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xlog.c File Reference
#include "postgres.h"
#include <ctype.h>
#include <math.h>
#include <time.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <unistd.h>
#include "access/clog.h"
#include "access/commit_ts.h"
#include "access/heaptoast.h"
#include "access/multixact.h"
#include "access/rewriteheap.h"
#include "access/subtrans.h"
#include "access/timeline.h"
#include "access/transam.h"
#include "access/twophase.h"
#include "access/xact.h"
#include "access/xlog_internal.h"
#include "access/xlogarchive.h"
#include "access/xloginsert.h"
#include "access/xlogreader.h"
#include "access/xlogrecovery.h"
#include "access/xlogutils.h"
#include "backup/basebackup.h"
#include "catalog/catversion.h"
#include "catalog/pg_control.h"
#include "catalog/pg_database.h"
#include "common/controldata_utils.h"
#include "common/file_utils.h"
#include "executor/instrument.h"
#include "miscadmin.h"
#include "pg_trace.h"
#include "pgstat.h"
#include "port/atomics.h"
#include "postmaster/bgwriter.h"
#include "postmaster/startup.h"
#include "postmaster/walsummarizer.h"
#include "postmaster/walwriter.h"
#include "replication/origin.h"
#include "replication/slot.h"
#include "replication/snapbuild.h"
#include "replication/walreceiver.h"
#include "replication/walsender.h"
#include "storage/bufmgr.h"
#include "storage/fd.h"
#include "storage/ipc.h"
#include "storage/large_object.h"
#include "storage/latch.h"
#include "storage/predicate.h"
#include "storage/proc.h"
#include "storage/procarray.h"
#include "storage/reinit.h"
#include "storage/spin.h"
#include "storage/sync.h"
#include "utils/guc_hooks.h"
#include "utils/guc_tables.h"
#include "utils/injection_point.h"
#include "utils/ps_status.h"
#include "utils/relmapper.h"
#include "utils/snapmgr.h"
#include "utils/timeout.h"
#include "utils/timestamp.h"
#include "utils/varlena.h"
Include dependency graph for xlog.c:

Go to the source code of this file.

Data Structures

struct  XLogwrtRqst
 
struct  XLogwrtResult
 
struct  WALInsertLock
 
union  WALInsertLockPadded
 
struct  XLogCtlInsert
 
struct  XLogCtlData
 

Macros

#define BootstrapTimeLineID   1
 
#define NUM_XLOGINSERT_LOCKS   8
 
#define INSERT_FREESPACE(endptr)    (((endptr) % XLOG_BLCKSZ == 0) ? 0 : (XLOG_BLCKSZ - (endptr) % XLOG_BLCKSZ))
 
#define NextBufIdx(idx)    (((idx) == XLogCtl->XLogCacheBlck) ? 0 : ((idx) + 1))
 
#define XLogRecPtrToBufIdx(recptr)    (((recptr) / XLOG_BLCKSZ) % (XLogCtl->XLogCacheBlck + 1))
 
#define UsableBytesInPage   (XLOG_BLCKSZ - SizeOfXLogShortPHD)
 
#define ConvertToXSegs(x, segsize)   XLogMBVarToSegs((x), (segsize))
 
#define RefreshXLogWriteResult(_target)
 

Typedefs

typedef struct XLogwrtRqst XLogwrtRqst
 
typedef struct XLogwrtResult XLogwrtResult
 
typedef union WALInsertLockPadded WALInsertLockPadded
 
typedef struct XLogCtlInsert XLogCtlInsert
 
typedef struct XLogCtlData XLogCtlData
 

Enumerations

enum  WalInsertClass { WALINSERT_NORMAL , WALINSERT_SPECIAL_SWITCH , WALINSERT_SPECIAL_CHECKPOINT }
 

Functions

static void CleanupAfterArchiveRecovery (TimeLineID EndOfLogTLI, XLogRecPtr EndOfLog, TimeLineID newTLI)
 
static void CheckRequiredParameterValues (void)
 
static void XLogReportParameters (void)
 
static int LocalSetXLogInsertAllowed (void)
 
static void CreateEndOfRecoveryRecord (void)
 
static XLogRecPtr CreateOverwriteContrecordRecord (XLogRecPtr aborted_lsn, XLogRecPtr pagePtr, TimeLineID newTLI)
 
static void CheckPointGuts (XLogRecPtr checkPointRedo, int flags)
 
static void KeepLogSeg (XLogRecPtr recptr, XLogSegNo *logSegNo)
 
static XLogRecPtr XLogGetReplicationSlotMinimumLSN (void)
 
static void AdvanceXLInsertBuffer (XLogRecPtr upto, TimeLineID tli, bool opportunistic)
 
static void XLogWrite (XLogwrtRqst WriteRqst, TimeLineID tli, bool flexible)
 
static bool InstallXLogFileSegment (XLogSegNo *segno, char *tmppath, bool find_free, XLogSegNo max_segno, TimeLineID tli)
 
static void XLogFileClose (void)
 
static void PreallocXlogFiles (XLogRecPtr endptr, TimeLineID tli)
 
static void RemoveTempXlogFiles (void)
 
static void RemoveOldXlogFiles (XLogSegNo segno, XLogRecPtr lastredoptr, XLogRecPtr endptr, TimeLineID insertTLI)
 
static void RemoveXlogFile (const struct dirent *segment_de, XLogSegNo recycleSegNo, XLogSegNo *endlogSegNo, TimeLineID insertTLI)
 
static void UpdateLastRemovedPtr (char *filename)
 
static void ValidateXLOGDirectoryStructure (void)
 
static void CleanupBackupHistory (void)
 
static void UpdateMinRecoveryPoint (XLogRecPtr lsn, bool force)
 
static bool PerformRecoveryXLogAction (void)
 
static void InitControlFile (uint64 sysidentifier, uint32 data_checksum_version)
 
static void WriteControlFile (void)
 
static void ReadControlFile (void)
 
static void UpdateControlFile (void)
 
static char * str_time (pg_time_t tnow)
 
static int get_sync_bit (int method)
 
static void CopyXLogRecordToWAL (int write_len, bool isLogSwitch, XLogRecData *rdata, XLogRecPtr StartPos, XLogRecPtr EndPos, TimeLineID tli)
 
static void ReserveXLogInsertLocation (int size, XLogRecPtr *StartPos, XLogRecPtr *EndPos, XLogRecPtr *PrevPtr)
 
static bool ReserveXLogSwitch (XLogRecPtr *StartPos, XLogRecPtr *EndPos, XLogRecPtr *PrevPtr)
 
static XLogRecPtr WaitXLogInsertionsToFinish (XLogRecPtr upto)
 
static char * GetXLogBuffer (XLogRecPtr ptr, TimeLineID tli)
 
static XLogRecPtr XLogBytePosToRecPtr (uint64 bytepos)
 
static XLogRecPtr XLogBytePosToEndRecPtr (uint64 bytepos)
 
static uint64 XLogRecPtrToBytePos (XLogRecPtr ptr)
 
static void WALInsertLockAcquire (void)
 
static void WALInsertLockAcquireExclusive (void)
 
static void WALInsertLockRelease (void)
 
static void WALInsertLockUpdateInsertingAt (XLogRecPtr insertingAt)
 
XLogRecPtr XLogInsertRecord (XLogRecData *rdata, XLogRecPtr fpw_lsn, uint8 flags, int num_fpi, bool topxid_included)
 
Size WALReadFromBuffers (char *dstbuf, XLogRecPtr startptr, Size count, TimeLineID tli)
 
static void CalculateCheckpointSegments (void)
 
void assign_max_wal_size (int newval, void *extra)
 
void assign_checkpoint_completion_target (double newval, void *extra)
 
bool check_wal_segment_size (int *newval, void **extra, GucSource source)
 
bool check_max_slot_wal_keep_size (int *newval, void **extra, GucSource source)
 
static XLogSegNo XLOGfileslop (XLogRecPtr lastredoptr)
 
bool XLogCheckpointNeeded (XLogSegNo new_segno)
 
void XLogSetAsyncXactLSN (XLogRecPtr asyncXactLSN)
 
void XLogSetReplicationSlotMinimumLSN (XLogRecPtr lsn)
 
void XLogFlush (XLogRecPtr record)
 
bool XLogBackgroundFlush (void)
 
bool XLogNeedsFlush (XLogRecPtr record)
 
static int XLogFileInitInternal (XLogSegNo logsegno, TimeLineID logtli, bool *added, char *path)
 
int XLogFileInit (XLogSegNo logsegno, TimeLineID logtli)
 
static void XLogFileCopy (TimeLineID destTLI, XLogSegNo destsegno, TimeLineID srcTLI, XLogSegNo srcsegno, int upto)
 
int XLogFileOpen (XLogSegNo segno, TimeLineID tli)
 
void CheckXLogRemoved (XLogSegNo segno, TimeLineID tli)
 
XLogSegNo XLogGetLastRemovedSegno (void)
 
XLogSegNo XLogGetOldestSegno (TimeLineID tli)
 
void RemoveNonParentXlogFiles (XLogRecPtr switchpoint, TimeLineID newTLI)
 
uint64 GetSystemIdentifier (void)
 
char * GetMockAuthenticationNonce (void)
 
bool DataChecksumsEnabled (void)
 
XLogRecPtr GetFakeLSNForUnloggedRel (void)
 
static int XLOGChooseNumBuffers (void)
 
bool check_wal_buffers (int *newval, void **extra, GucSource source)
 
bool check_wal_consistency_checking (char **newval, void **extra, GucSource source)
 
void assign_wal_consistency_checking (const char *newval, void *extra)
 
void InitializeWalConsistencyChecking (void)
 
const char * show_archive_command (void)
 
const char * show_in_hot_standby (void)
 
void LocalProcessControlFile (bool reset)
 
WalLevel GetActiveWalLevelOnStandby (void)
 
Size XLOGShmemSize (void)
 
void XLOGShmemInit (void)
 
void BootStrapXLOG (uint32 data_checksum_version)
 
static void XLogInitNewTimeline (TimeLineID endTLI, XLogRecPtr endOfLog, TimeLineID newTLI)
 
void StartupXLOG (void)
 
void SwitchIntoArchiveRecovery (XLogRecPtr EndRecPtr, TimeLineID replayTLI)
 
void ReachedEndOfBackup (XLogRecPtr EndRecPtr, TimeLineID tli)
 
bool RecoveryInProgress (void)
 
RecoveryState GetRecoveryState (void)
 
bool XLogInsertAllowed (void)
 
XLogRecPtr GetRedoRecPtr (void)
 
void GetFullPageWriteInfo (XLogRecPtr *RedoRecPtr_p, bool *doPageWrites_p)
 
XLogRecPtr GetInsertRecPtr (void)
 
XLogRecPtr GetFlushRecPtr (TimeLineID *insertTLI)
 
TimeLineID GetWALInsertionTimeLine (void)
 
TimeLineID GetWALInsertionTimeLineIfSet (void)
 
XLogRecPtr GetLastImportantRecPtr (void)
 
pg_time_t GetLastSegSwitchData (XLogRecPtr *lastSwitchLSN)
 
void ShutdownXLOG (int code, Datum arg)
 
static void LogCheckpointStart (int flags, bool restartpoint)
 
static void LogCheckpointEnd (bool restartpoint)
 
static void UpdateCheckPointDistanceEstimate (uint64 nbytes)
 
static void update_checkpoint_display (int flags, bool restartpoint, bool reset)
 
bool CreateCheckPoint (int flags)
 
static void RecoveryRestartPoint (const CheckPoint *checkPoint, XLogReaderState *record)
 
bool CreateRestartPoint (int flags)
 
WALAvailability GetWALAvailability (XLogRecPtr targetLSN)
 
void XLogPutNextOid (Oid nextOid)
 
XLogRecPtr RequestXLogSwitch (bool mark_unimportant)
 
XLogRecPtr XLogRestorePoint (const char *rpName)
 
void UpdateFullPageWrites (void)
 
void xlog_redo (XLogReaderState *record)
 
void assign_wal_sync_method (int new_wal_sync_method, void *extra)
 
void issue_xlog_fsync (int fd, XLogSegNo segno, TimeLineID tli)
 
void do_pg_backup_start (const char *backupidstr, bool fast, List **tablespaces, BackupState *state, StringInfo tblspcmapfile)
 
SessionBackupState get_backup_status (void)
 
void do_pg_backup_stop (BackupState *state, bool waitforarchive)
 
void do_pg_abort_backup (int code, Datum arg)
 
void register_persistent_abort_backup_handler (void)
 
XLogRecPtr GetXLogInsertRecPtr (void)
 
XLogRecPtr GetXLogWriteRecPtr (void)
 
void GetOldestRestartPoint (XLogRecPtr *oldrecptr, TimeLineID *oldtli)
 
void XLogShutdownWalRcv (void)
 
void SetInstallXLogFileSegmentActive (void)
 
bool IsInstallXLogFileSegmentActive (void)
 
void SetWalWriterSleeping (bool sleeping)
 

Variables

int max_wal_size_mb = 1024
 
int min_wal_size_mb = 80
 
int wal_keep_size_mb = 0
 
int XLOGbuffers = -1
 
int XLogArchiveTimeout = 0
 
int XLogArchiveMode = ARCHIVE_MODE_OFF
 
char * XLogArchiveCommand = NULL
 
bool EnableHotStandby = false
 
bool fullPageWrites = true
 
bool wal_log_hints = false
 
int wal_compression = WAL_COMPRESSION_NONE
 
char * wal_consistency_checking_string = NULL
 
bool * wal_consistency_checking = NULL
 
bool wal_init_zero = true
 
bool wal_recycle = true
 
bool log_checkpoints = true
 
int wal_sync_method = DEFAULT_WAL_SYNC_METHOD
 
int wal_level = WAL_LEVEL_REPLICA
 
int CommitDelay = 0
 
int CommitSiblings = 5
 
int wal_retrieve_retry_interval = 5000
 
int max_slot_wal_keep_size_mb = -1
 
int wal_decode_buffer_size = 512 * 1024
 
bool track_wal_io_timing = false
 
int wal_segment_size = DEFAULT_XLOG_SEG_SIZE
 
int CheckPointSegments
 
static double CheckPointDistanceEstimate = 0
 
static double PrevCheckPointDistance = 0
 
static bool check_wal_consistency_checking_deferred = false
 
const struct config_enum_entry wal_sync_method_options []
 
const struct config_enum_entry archive_mode_options []
 
CheckpointStatsData CheckpointStats
 
static bool lastFullPageWrites
 
static bool LocalRecoveryInProgress = true
 
static int LocalXLogInsertAllowed = -1
 
XLogRecPtr ProcLastRecPtr = InvalidXLogRecPtr
 
XLogRecPtr XactLastRecEnd = InvalidXLogRecPtr
 
XLogRecPtr XactLastCommitEnd = InvalidXLogRecPtr
 
static XLogRecPtr RedoRecPtr
 
static bool doPageWrites
 
static SessionBackupState sessionBackupState = SESSION_BACKUP_NONE
 
static XLogCtlDataXLogCtl = NULL
 
static WALInsertLockPaddedWALInsertLocks = NULL
 
static ControlFileDataControlFile = NULL
 
static int UsableBytesInSegment
 
static XLogwrtResult LogwrtResult = {0, 0}
 
static int openLogFile = -1
 
static XLogSegNo openLogSegNo = 0
 
static TimeLineID openLogTLI = 0
 
static XLogRecPtr LocalMinRecoveryPoint
 
static TimeLineID LocalMinRecoveryPointTLI
 
static bool updateMinRecoveryPoint = true
 
static int MyLockNo = 0
 
static bool holdingAllLocks = false
 

Macro Definition Documentation

◆ BootstrapTimeLineID

#define BootstrapTimeLineID   1

Definition at line 111 of file xlog.c.

◆ ConvertToXSegs

#define ConvertToXSegs (   x,
  segsize 
)    XLogMBVarToSegs((x), (segsize))

Definition at line 603 of file xlog.c.

◆ INSERT_FREESPACE

#define INSERT_FREESPACE (   endptr)     (((endptr) % XLOG_BLCKSZ == 0) ? 0 : (XLOG_BLCKSZ - (endptr) % XLOG_BLCKSZ))

Definition at line 580 of file xlog.c.

◆ NextBufIdx

#define NextBufIdx (   idx)     (((idx) == XLogCtl->XLogCacheBlck) ? 0 : ((idx) + 1))

Definition at line 584 of file xlog.c.

◆ NUM_XLOGINSERT_LOCKS

#define NUM_XLOGINSERT_LOCKS   8

Definition at line 150 of file xlog.c.

◆ RefreshXLogWriteResult

#define RefreshXLogWriteResult (   _target)
Value:
do { \
pg_read_barrier(); \
} while (0)
static uint64 pg_atomic_read_u64(volatile pg_atomic_uint64 *ptr)
Definition: atomics.h:467
pg_atomic_uint64 logWriteResult
Definition: xlog.c:472
pg_atomic_uint64 logFlushResult
Definition: xlog.c:473
static XLogCtlData * XLogCtl
Definition: xlog.c:566

Definition at line 620 of file xlog.c.

◆ UsableBytesInPage

#define UsableBytesInPage   (XLOG_BLCKSZ - SizeOfXLogShortPHD)

Definition at line 597 of file xlog.c.

◆ XLogRecPtrToBufIdx

#define XLogRecPtrToBufIdx (   recptr)     (((recptr) / XLOG_BLCKSZ) % (XLogCtl->XLogCacheBlck + 1))

Definition at line 591 of file xlog.c.

Typedef Documentation

◆ WALInsertLockPadded

◆ XLogCtlData

typedef struct XLogCtlData XLogCtlData

◆ XLogCtlInsert

typedef struct XLogCtlInsert XLogCtlInsert

◆ XLogwrtResult

typedef struct XLogwrtResult XLogwrtResult

◆ XLogwrtRqst

typedef struct XLogwrtRqst XLogwrtRqst

Enumeration Type Documentation

◆ WalInsertClass

Enumerator
WALINSERT_NORMAL 
WALINSERT_SPECIAL_SWITCH 
WALINSERT_SPECIAL_CHECKPOINT 

Definition at line 559 of file xlog.c.

560{
WalInsertClass
Definition: xlog.c:560
@ WALINSERT_SPECIAL_SWITCH
Definition: xlog.c:562
@ WALINSERT_NORMAL
Definition: xlog.c:561
@ WALINSERT_SPECIAL_CHECKPOINT
Definition: xlog.c:563

Function Documentation

◆ AdvanceXLInsertBuffer()

static void AdvanceXLInsertBuffer ( XLogRecPtr  upto,
TimeLineID  tli,
bool  opportunistic 
)
static

Definition at line 1985 of file xlog.c.

1986{
1988 int nextidx;
1989 XLogRecPtr OldPageRqstPtr;
1990 XLogwrtRqst WriteRqst;
1991 XLogRecPtr NewPageEndPtr = InvalidXLogRecPtr;
1992 XLogRecPtr NewPageBeginPtr;
1993 XLogPageHeader NewPage;
1994 int npages pg_attribute_unused() = 0;
1995
1996 LWLockAcquire(WALBufMappingLock, LW_EXCLUSIVE);
1997
1998 /*
1999 * Now that we have the lock, check if someone initialized the page
2000 * already.
2001 */
2002 while (upto >= XLogCtl->InitializedUpTo || opportunistic)
2003 {
2005
2006 /*
2007 * Get ending-offset of the buffer page we need to replace (this may
2008 * be zero if the buffer hasn't been used yet). Fall through if it's
2009 * already written out.
2010 */
2011 OldPageRqstPtr = pg_atomic_read_u64(&XLogCtl->xlblocks[nextidx]);
2012 if (LogwrtResult.Write < OldPageRqstPtr)
2013 {
2014 /*
2015 * Nope, got work to do. If we just want to pre-initialize as much
2016 * as we can without flushing, give up now.
2017 */
2018 if (opportunistic)
2019 break;
2020
2021 /* Advance shared memory write request position */
2023 if (XLogCtl->LogwrtRqst.Write < OldPageRqstPtr)
2024 XLogCtl->LogwrtRqst.Write = OldPageRqstPtr;
2026
2027 /*
2028 * Acquire an up-to-date LogwrtResult value and see if we still
2029 * need to write it or if someone else already did.
2030 */
2032 if (LogwrtResult.Write < OldPageRqstPtr)
2033 {
2034 /*
2035 * Must acquire write lock. Release WALBufMappingLock first,
2036 * to make sure that all insertions that we need to wait for
2037 * can finish (up to this same position). Otherwise we risk
2038 * deadlock.
2039 */
2040 LWLockRelease(WALBufMappingLock);
2041
2042 WaitXLogInsertionsToFinish(OldPageRqstPtr);
2043
2044 LWLockAcquire(WALWriteLock, LW_EXCLUSIVE);
2045
2047 if (LogwrtResult.Write >= OldPageRqstPtr)
2048 {
2049 /* OK, someone wrote it already */
2050 LWLockRelease(WALWriteLock);
2051 }
2052 else
2053 {
2054 /* Have to write it ourselves */
2055 TRACE_POSTGRESQL_WAL_BUFFER_WRITE_DIRTY_START();
2056 WriteRqst.Write = OldPageRqstPtr;
2057 WriteRqst.Flush = 0;
2058 XLogWrite(WriteRqst, tli, false);
2059 LWLockRelease(WALWriteLock);
2061 TRACE_POSTGRESQL_WAL_BUFFER_WRITE_DIRTY_DONE();
2062 }
2063 /* Re-acquire WALBufMappingLock and retry */
2064 LWLockAcquire(WALBufMappingLock, LW_EXCLUSIVE);
2065 continue;
2066 }
2067 }
2068
2069 /*
2070 * Now the next buffer slot is free and we can set it up to be the
2071 * next output page.
2072 */
2073 NewPageBeginPtr = XLogCtl->InitializedUpTo;
2074 NewPageEndPtr = NewPageBeginPtr + XLOG_BLCKSZ;
2075
2076 Assert(XLogRecPtrToBufIdx(NewPageBeginPtr) == nextidx);
2077
2078 NewPage = (XLogPageHeader) (XLogCtl->pages + nextidx * (Size) XLOG_BLCKSZ);
2079
2080 /*
2081 * Mark the xlblock with InvalidXLogRecPtr and issue a write barrier
2082 * before initializing. Otherwise, the old page may be partially
2083 * zeroed but look valid.
2084 */
2087
2088 /*
2089 * Be sure to re-zero the buffer so that bytes beyond what we've
2090 * written will look like zeroes and not valid XLOG records...
2091 */
2092 MemSet((char *) NewPage, 0, XLOG_BLCKSZ);
2093
2094 /*
2095 * Fill the new page's header
2096 */
2097 NewPage->xlp_magic = XLOG_PAGE_MAGIC;
2098
2099 /* NewPage->xlp_info = 0; */ /* done by memset */
2100 NewPage->xlp_tli = tli;
2101 NewPage->xlp_pageaddr = NewPageBeginPtr;
2102
2103 /* NewPage->xlp_rem_len = 0; */ /* done by memset */
2104
2105 /*
2106 * If online backup is not in progress, mark the header to indicate
2107 * that WAL records beginning in this page have removable backup
2108 * blocks. This allows the WAL archiver to know whether it is safe to
2109 * compress archived WAL data by transforming full-block records into
2110 * the non-full-block format. It is sufficient to record this at the
2111 * page level because we force a page switch (in fact a segment
2112 * switch) when starting a backup, so the flag will be off before any
2113 * records can be written during the backup. At the end of a backup,
2114 * the last page will be marked as all unsafe when perhaps only part
2115 * is unsafe, but at worst the archiver would miss the opportunity to
2116 * compress a few records.
2117 */
2118 if (Insert->runningBackups == 0)
2119 NewPage->xlp_info |= XLP_BKP_REMOVABLE;
2120
2121 /*
2122 * If first page of an XLOG segment file, make it a long header.
2123 */
2124 if ((XLogSegmentOffset(NewPage->xlp_pageaddr, wal_segment_size)) == 0)
2125 {
2126 XLogLongPageHeader NewLongPage = (XLogLongPageHeader) NewPage;
2127
2128 NewLongPage->xlp_sysid = ControlFile->system_identifier;
2129 NewLongPage->xlp_seg_size = wal_segment_size;
2130 NewLongPage->xlp_xlog_blcksz = XLOG_BLCKSZ;
2131 NewPage->xlp_info |= XLP_LONG_HEADER;
2132 }
2133
2134 /*
2135 * Make sure the initialization of the page becomes visible to others
2136 * before the xlblocks update. GetXLogBuffer() reads xlblocks without
2137 * holding a lock.
2138 */
2140
2141 pg_atomic_write_u64(&XLogCtl->xlblocks[nextidx], NewPageEndPtr);
2142 XLogCtl->InitializedUpTo = NewPageEndPtr;
2143
2144 npages++;
2145 }
2146 LWLockRelease(WALBufMappingLock);
2147
2148#ifdef WAL_DEBUG
2149 if (XLOG_DEBUG && npages > 0)
2150 {
2151 elog(DEBUG1, "initialized %d pages, up to %X/%X",
2152 npages, LSN_FORMAT_ARGS(NewPageEndPtr));
2153 }
2154#endif
2155}
static void pg_atomic_write_u64(volatile pg_atomic_uint64 *ptr, uint64 val)
Definition: atomics.h:485
#define pg_write_barrier()
Definition: atomics.h:157
#define pg_attribute_unused()
Definition: c.h:130
#define Assert(condition)
Definition: c.h:812
#define MemSet(start, val, len)
Definition: c.h:974
size_t Size
Definition: c.h:559
#define DEBUG1
Definition: elog.h:30
#define elog(elevel,...)
Definition: elog.h:225
static void Insert(File file)
Definition: fd.c:1312
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1168
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1781
@ LW_EXCLUSIVE
Definition: lwlock.h:114
PgStat_PendingWalStats PendingWalStats
Definition: pgstat_wal.c:24
#define SpinLockRelease(lock)
Definition: spin.h:61
#define SpinLockAcquire(lock)
Definition: spin.h:59
uint64 system_identifier
Definition: pg_control.h:110
PgStat_Counter wal_buffers_full
Definition: pgstat.h:519
XLogwrtRqst LogwrtRqst
Definition: xlog.c:455
slock_t info_lck
Definition: xlog.c:553
XLogRecPtr InitializedUpTo
Definition: xlog.c:485
char * pages
Definition: xlog.c:492
pg_atomic_uint64 * xlblocks
Definition: xlog.c:493
XLogCtlInsert Insert
Definition: xlog.c:452
TimeLineID xlp_tli
Definition: xlog_internal.h:40
XLogRecPtr xlp_pageaddr
Definition: xlog_internal.h:41
XLogRecPtr Write
Definition: xlog.c:327
XLogRecPtr Flush
Definition: xlog.c:322
XLogRecPtr Write
Definition: xlog.c:321
static XLogRecPtr WaitXLogInsertionsToFinish(XLogRecPtr upto)
Definition: xlog.c:1504
#define RefreshXLogWriteResult(_target)
Definition: xlog.c:620
int wal_segment_size
Definition: xlog.c:143
static XLogwrtResult LogwrtResult
Definition: xlog.c:612
#define XLogRecPtrToBufIdx(recptr)
Definition: xlog.c:591
static void XLogWrite(XLogwrtRqst WriteRqst, TimeLineID tli, bool flexible)
Definition: xlog.c:2314
static ControlFileData * ControlFile
Definition: xlog.c:574
XLogLongPageHeaderData * XLogLongPageHeader
Definition: xlog_internal.h:71
#define XLogSegmentOffset(xlogptr, wal_segsz_bytes)
XLogPageHeaderData * XLogPageHeader
Definition: xlog_internal.h:54
#define XLP_LONG_HEADER
Definition: xlog_internal.h:76
#define XLP_BKP_REMOVABLE
Definition: xlog_internal.h:78
#define XLOG_PAGE_MAGIC
Definition: xlog_internal.h:34
#define LSN_FORMAT_ARGS(lsn)
Definition: xlogdefs.h:43
uint64 XLogRecPtr
Definition: xlogdefs.h:21
#define InvalidXLogRecPtr
Definition: xlogdefs.h:28

References Assert, ControlFile, DEBUG1, elog, XLogwrtRqst::Flush, XLogCtlData::info_lck, XLogCtlData::InitializedUpTo, XLogCtlData::Insert, Insert(), InvalidXLogRecPtr, LogwrtResult, XLogCtlData::LogwrtRqst, LSN_FORMAT_ARGS, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), MemSet, XLogCtlData::pages, PendingWalStats, pg_atomic_read_u64(), pg_atomic_write_u64(), pg_attribute_unused, pg_write_barrier, RefreshXLogWriteResult, SpinLockAcquire, SpinLockRelease, ControlFileData::system_identifier, WaitXLogInsertionsToFinish(), PgStat_PendingWalStats::wal_buffers_full, wal_segment_size, XLogwrtRqst::Write, XLogwrtResult::Write, XLogCtlData::xlblocks, XLOG_PAGE_MAGIC, XLogCtl, XLogRecPtrToBufIdx, XLogSegmentOffset, XLogWrite(), XLP_BKP_REMOVABLE, XLP_LONG_HEADER, XLogLongPageHeaderData::xlp_seg_size, XLogLongPageHeaderData::xlp_sysid, and XLogLongPageHeaderData::xlp_xlog_blcksz.

Referenced by GetXLogBuffer(), and XLogBackgroundFlush().

◆ assign_checkpoint_completion_target()

void assign_checkpoint_completion_target ( double  newval,
void *  extra 
)

Definition at line 2198 of file xlog.c.

2199{
2202}
double CheckPointCompletionTarget
Definition: checkpointer.c:138
#define newval
static void CalculateCheckpointSegments(void)
Definition: xlog.c:2162

References CalculateCheckpointSegments(), CheckPointCompletionTarget, and newval.

◆ assign_max_wal_size()

void assign_max_wal_size ( int  newval,
void *  extra 
)

Definition at line 2191 of file xlog.c.

2192{
2195}
int max_wal_size_mb
Definition: xlog.c:114

References CalculateCheckpointSegments(), max_wal_size_mb, and newval.

◆ assign_wal_consistency_checking()

void assign_wal_consistency_checking ( const char *  newval,
void *  extra 
)

Definition at line 4757 of file xlog.c.

4758{
4759 /*
4760 * If some checks were deferred, it's possible that the checks will fail
4761 * later during InitializeWalConsistencyChecking(). But in that case, the
4762 * postmaster will exit anyway, so it's safe to proceed with the
4763 * assignment.
4764 *
4765 * Any built-in resource managers specified are assigned immediately,
4766 * which affects WAL created before shared_preload_libraries are
4767 * processed. Any custom resource managers specified won't be assigned
4768 * until after shared_preload_libraries are processed, but that's OK
4769 * because WAL for a custom resource manager can't be written before the
4770 * module is loaded anyway.
4771 */
4773}
bool * wal_consistency_checking
Definition: xlog.c:126

References wal_consistency_checking.

◆ assign_wal_sync_method()

void assign_wal_sync_method ( int  new_wal_sync_method,
void *  extra 
)

Definition at line 8641 of file xlog.c.

8642{
8643 if (wal_sync_method != new_wal_sync_method)
8644 {
8645 /*
8646 * To ensure that no blocks escape unsynced, force an fsync on the
8647 * currently open log segment (if any). Also, if the open flag is
8648 * changing, close the log file so it will be reopened (with new flag
8649 * bit) at next use.
8650 */
8651 if (openLogFile >= 0)
8652 {
8653 pgstat_report_wait_start(WAIT_EVENT_WAL_SYNC_METHOD_ASSIGN);
8654 if (pg_fsync(openLogFile) != 0)
8655 {
8656 char xlogfname[MAXFNAMELEN];
8657 int save_errno;
8658
8659 save_errno = errno;
8662 errno = save_errno;
8663 ereport(PANIC,
8665 errmsg("could not fsync file \"%s\": %m", xlogfname)));
8666 }
8667
8669 if (get_sync_bit(wal_sync_method) != get_sync_bit(new_wal_sync_method))
8670 XLogFileClose();
8671 }
8672 }
8673}
int errcode_for_file_access(void)
Definition: elog.c:876
int errmsg(const char *fmt,...)
Definition: elog.c:1070
#define PANIC
Definition: elog.h:42
#define ereport(elevel,...)
Definition: elog.h:149
int pg_fsync(int fd)
Definition: fd.c:385
static void pgstat_report_wait_start(uint32 wait_event_info)
Definition: wait_event.h:85
static void pgstat_report_wait_end(void)
Definition: wait_event.h:101
static int openLogFile
Definition: xlog.c:635
static int get_sync_bit(int method)
Definition: xlog.c:8593
int wal_sync_method
Definition: xlog.c:130
static TimeLineID openLogTLI
Definition: xlog.c:637
static void XLogFileClose(void)
Definition: xlog.c:3639
static XLogSegNo openLogSegNo
Definition: xlog.c:636
#define MAXFNAMELEN
static void XLogFileName(char *fname, TimeLineID tli, XLogSegNo logSegNo, int wal_segsz_bytes)

References ereport, errcode_for_file_access(), errmsg(), get_sync_bit(), MAXFNAMELEN, openLogFile, openLogSegNo, openLogTLI, PANIC, pg_fsync(), pgstat_report_wait_end(), pgstat_report_wait_start(), wal_segment_size, wal_sync_method, XLogFileClose(), and XLogFileName().

◆ BootStrapXLOG()

void BootStrapXLOG ( uint32  data_checksum_version)

Definition at line 5033 of file xlog.c.

5034{
5035 CheckPoint checkPoint;
5036 char *buffer;
5037 XLogPageHeader page;
5038 XLogLongPageHeader longpage;
5039 XLogRecord *record;
5040 char *recptr;
5041 uint64 sysidentifier;
5042 struct timeval tv;
5043 pg_crc32c crc;
5044
5045 /* allow ordinary WAL segment creation, like StartupXLOG() would */
5047
5048 /*
5049 * Select a hopefully-unique system identifier code for this installation.
5050 * We use the result of gettimeofday(), including the fractional seconds
5051 * field, as being about as unique as we can easily get. (Think not to
5052 * use random(), since it hasn't been seeded and there's no portable way
5053 * to seed it other than the system clock value...) The upper half of the
5054 * uint64 value is just the tv_sec part, while the lower half contains the
5055 * tv_usec part (which must fit in 20 bits), plus 12 bits from our current
5056 * PID for a little extra uniqueness. A person knowing this encoding can
5057 * determine the initialization time of the installation, which could
5058 * perhaps be useful sometimes.
5059 */
5060 gettimeofday(&tv, NULL);
5061 sysidentifier = ((uint64) tv.tv_sec) << 32;
5062 sysidentifier |= ((uint64) tv.tv_usec) << 12;
5063 sysidentifier |= getpid() & 0xFFF;
5064
5065 /* page buffer must be aligned suitably for O_DIRECT */
5066 buffer = (char *) palloc(XLOG_BLCKSZ + XLOG_BLCKSZ);
5067 page = (XLogPageHeader) TYPEALIGN(XLOG_BLCKSZ, buffer);
5068 memset(page, 0, XLOG_BLCKSZ);
5069
5070 /*
5071 * Set up information for the initial checkpoint record
5072 *
5073 * The initial checkpoint record is written to the beginning of the WAL
5074 * segment with logid=0 logseg=1. The very first WAL segment, 0/0, is not
5075 * used, so that we can use 0/0 to mean "before any valid WAL segment".
5076 */
5080 checkPoint.fullPageWrites = fullPageWrites;
5081 checkPoint.wal_level = wal_level;
5082 checkPoint.nextXid =
5084 checkPoint.nextOid = FirstGenbkiObjectId;
5085 checkPoint.nextMulti = FirstMultiXactId;
5086 checkPoint.nextMultiOffset = 0;
5088 checkPoint.oldestXidDB = Template1DbOid;
5089 checkPoint.oldestMulti = FirstMultiXactId;
5090 checkPoint.oldestMultiDB = Template1DbOid;
5093 checkPoint.time = (pg_time_t) time(NULL);
5095
5096 TransamVariables->nextXid = checkPoint.nextXid;
5097 TransamVariables->nextOid = checkPoint.nextOid;
5099 MultiXactSetNextMXact(checkPoint.nextMulti, checkPoint.nextMultiOffset);
5100 AdvanceOldestClogXid(checkPoint.oldestXid);
5101 SetTransactionIdLimit(checkPoint.oldestXid, checkPoint.oldestXidDB);
5102 SetMultiXactIdLimit(checkPoint.oldestMulti, checkPoint.oldestMultiDB, true);
5104
5105 /* Set up the XLOG page header */
5106 page->xlp_magic = XLOG_PAGE_MAGIC;
5107 page->xlp_info = XLP_LONG_HEADER;
5110 longpage = (XLogLongPageHeader) page;
5111 longpage->xlp_sysid = sysidentifier;
5112 longpage->xlp_seg_size = wal_segment_size;
5113 longpage->xlp_xlog_blcksz = XLOG_BLCKSZ;
5114
5115 /* Insert the initial checkpoint record */
5116 recptr = ((char *) page + SizeOfXLogLongPHD);
5117 record = (XLogRecord *) recptr;
5118 record->xl_prev = 0;
5119 record->xl_xid = InvalidTransactionId;
5120 record->xl_tot_len = SizeOfXLogRecord + SizeOfXLogRecordDataHeaderShort + sizeof(checkPoint);
5122 record->xl_rmid = RM_XLOG_ID;
5123 recptr += SizeOfXLogRecord;
5124 /* fill the XLogRecordDataHeaderShort struct */
5125 *(recptr++) = (char) XLR_BLOCK_ID_DATA_SHORT;
5126 *(recptr++) = sizeof(checkPoint);
5127 memcpy(recptr, &checkPoint, sizeof(checkPoint));
5128 recptr += sizeof(checkPoint);
5129 Assert(recptr - (char *) record == record->xl_tot_len);
5130
5132 COMP_CRC32C(crc, ((char *) record) + SizeOfXLogRecord, record->xl_tot_len - SizeOfXLogRecord);
5133 COMP_CRC32C(crc, (char *) record, offsetof(XLogRecord, xl_crc));
5134 FIN_CRC32C(crc);
5135 record->xl_crc = crc;
5136
5137 /* Create first XLOG segment file */
5140
5141 /*
5142 * We needn't bother with Reserve/ReleaseExternalFD here, since we'll
5143 * close the file again in a moment.
5144 */
5145
5146 /* Write the first page with the initial record */
5147 errno = 0;
5148 pgstat_report_wait_start(WAIT_EVENT_WAL_BOOTSTRAP_WRITE);
5149 if (write(openLogFile, page, XLOG_BLCKSZ) != XLOG_BLCKSZ)
5150 {
5151 /* if write didn't set errno, assume problem is no disk space */
5152 if (errno == 0)
5153 errno = ENOSPC;
5154 ereport(PANIC,
5156 errmsg("could not write bootstrap write-ahead log file: %m")));
5157 }
5159
5160 pgstat_report_wait_start(WAIT_EVENT_WAL_BOOTSTRAP_SYNC);
5161 if (pg_fsync(openLogFile) != 0)
5162 ereport(PANIC,
5164 errmsg("could not fsync bootstrap write-ahead log file: %m")));
5166
5167 if (close(openLogFile) != 0)
5168 ereport(PANIC,
5170 errmsg("could not close bootstrap write-ahead log file: %m")));
5171
5172 openLogFile = -1;
5173
5174 /* Now create pg_control */
5175 InitControlFile(sysidentifier, data_checksum_version);
5176 ControlFile->time = checkPoint.time;
5177 ControlFile->checkPoint = checkPoint.redo;
5178 ControlFile->checkPointCopy = checkPoint;
5179
5180 /* some additional ControlFile fields are set in WriteControlFile() */
5182
5183 /* Bootstrap the commit log, too */
5184 BootStrapCLOG();
5188
5189 pfree(buffer);
5190
5191 /*
5192 * Force control file to be read - in contrast to normal processing we'd
5193 * otherwise never run the checks and GUC related initializations therein.
5194 */
5196}
#define TYPEALIGN(ALIGNVAL, LEN)
Definition: c.h:758
uint64_t uint64
Definition: c.h:486
void BootStrapCLOG(void)
Definition: clog.c:833
void BootStrapCommitTs(void)
Definition: commit_ts.c:596
void SetCommitTsLimit(TransactionId oldestXact, TransactionId newestXact)
Definition: commit_ts.c:909
#define close(a)
Definition: win32.h:12
#define write(a, b, c)
Definition: win32.h:14
void pfree(void *pointer)
Definition: mcxt.c:1521
void * palloc(Size size)
Definition: mcxt.c:1317
void MultiXactSetNextMXact(MultiXactId nextMulti, MultiXactOffset nextMultiOffset)
Definition: multixact.c:2328
void SetMultiXactIdLimit(MultiXactId oldest_datminmxid, Oid oldest_datoid, bool is_startup)
Definition: multixact.c:2362
void BootStrapMultiXact(void)
Definition: multixact.c:2034
#define FirstMultiXactId
Definition: multixact.h:25
#define XLOG_CHECKPOINT_SHUTDOWN
Definition: pg_control.h:68
uint32 pg_crc32c
Definition: pg_crc32c.h:38
#define COMP_CRC32C(crc, data, len)
Definition: pg_crc32c.h:98
#define INIT_CRC32C(crc)
Definition: pg_crc32c.h:41
#define FIN_CRC32C(crc)
Definition: pg_crc32c.h:103
return crc
int64 pg_time_t
Definition: pgtime.h:23
Oid oldestMultiDB
Definition: pg_control.h:51
MultiXactId oldestMulti
Definition: pg_control.h:50
MultiXactOffset nextMultiOffset
Definition: pg_control.h:47
TransactionId newestCommitTsXid
Definition: pg_control.h:55
TransactionId oldestXid
Definition: pg_control.h:48
TimeLineID PrevTimeLineID
Definition: pg_control.h:40
TimeLineID ThisTimeLineID
Definition: pg_control.h:39
Oid nextOid
Definition: pg_control.h:45
TransactionId oldestActiveXid
Definition: pg_control.h:64
bool fullPageWrites
Definition: pg_control.h:42
MultiXactId nextMulti
Definition: pg_control.h:46
FullTransactionId nextXid
Definition: pg_control.h:44
TransactionId oldestCommitTsXid
Definition: pg_control.h:53
pg_time_t time
Definition: pg_control.h:52
int wal_level
Definition: pg_control.h:43
XLogRecPtr redo
Definition: pg_control.h:37
Oid oldestXidDB
Definition: pg_control.h:49
CheckPoint checkPointCopy
Definition: pg_control.h:135
pg_time_t time
Definition: pg_control.h:132
XLogRecPtr checkPoint
Definition: pg_control.h:133
FullTransactionId nextXid
Definition: transam.h:220
XLogRecPtr xl_prev
Definition: xlogrecord.h:45
uint8 xl_info
Definition: xlogrecord.h:46
uint32 xl_tot_len
Definition: xlogrecord.h:43
TransactionId xl_xid
Definition: xlogrecord.h:44
RmgrId xl_rmid
Definition: xlogrecord.h:47
void BootStrapSUBTRANS(void)
Definition: subtrans.c:270
#define InvalidTransactionId
Definition: transam.h:31
#define FirstGenbkiObjectId
Definition: transam.h:195
#define FirstNormalTransactionId
Definition: transam.h:34
static FullTransactionId FullTransactionIdFromEpochAndXid(uint32 epoch, TransactionId xid)
Definition: transam.h:71
void SetTransactionIdLimit(TransactionId oldest_datfrozenxid, Oid oldest_datoid)
Definition: varsup.c:372
void AdvanceOldestClogXid(TransactionId oldest_datfrozenxid)
Definition: varsup.c:355
TransamVariablesData * TransamVariables
Definition: varsup.c:34
int gettimeofday(struct timeval *tp, void *tzp)
int XLogFileInit(XLogSegNo logsegno, TimeLineID logtli)
Definition: xlog.c:3380
bool fullPageWrites
Definition: xlog.c:122
static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version)
Definition: xlog.c:4204
void SetInstallXLogFileSegmentActive(void)
Definition: xlog.c:9484
int wal_level
Definition: xlog.c:131
static void WriteControlFile(void)
Definition: xlog.c:4239
#define BootstrapTimeLineID
Definition: xlog.c:111
static void ReadControlFile(void)
Definition: xlog.c:4321
#define SizeOfXLogLongPHD
Definition: xlog_internal.h:69
#define SizeOfXLogRecordDataHeaderShort
Definition: xlogrecord.h:217
#define XLR_BLOCK_ID_DATA_SHORT
Definition: xlogrecord.h:241
#define SizeOfXLogRecord
Definition: xlogrecord.h:55

References AdvanceOldestClogXid(), Assert, BootStrapCLOG(), BootStrapCommitTs(), BootStrapMultiXact(), BootStrapSUBTRANS(), BootstrapTimeLineID, ControlFileData::checkPoint, ControlFileData::checkPointCopy, close, COMP_CRC32C, ControlFile, crc, ereport, errcode_for_file_access(), errmsg(), FIN_CRC32C, FirstGenbkiObjectId, FirstMultiXactId, FirstNormalTransactionId, fullPageWrites, CheckPoint::fullPageWrites, FullTransactionIdFromEpochAndXid(), gettimeofday(), INIT_CRC32C, InitControlFile(), InvalidTransactionId, MultiXactSetNextMXact(), CheckPoint::newestCommitTsXid, CheckPoint::nextMulti, CheckPoint::nextMultiOffset, TransamVariablesData::nextOid, CheckPoint::nextOid, TransamVariablesData::nextXid, CheckPoint::nextXid, TransamVariablesData::oidCount, CheckPoint::oldestActiveXid, CheckPoint::oldestCommitTsXid, CheckPoint::oldestMulti, CheckPoint::oldestMultiDB, CheckPoint::oldestXid, CheckPoint::oldestXidDB, openLogFile, openLogTLI, palloc(), PANIC, pfree(), pg_fsync(), pgstat_report_wait_end(), pgstat_report_wait_start(), CheckPoint::PrevTimeLineID, ReadControlFile(), CheckPoint::redo, SetCommitTsLimit(), SetInstallXLogFileSegmentActive(), SetMultiXactIdLimit(), SetTransactionIdLimit(), SizeOfXLogLongPHD, SizeOfXLogRecord, SizeOfXLogRecordDataHeaderShort, CheckPoint::ThisTimeLineID, CheckPoint::time, ControlFileData::time, TransamVariables, TYPEALIGN, wal_level, CheckPoint::wal_level, wal_segment_size, write, WriteControlFile(), XLogRecord::xl_crc, XLogRecord::xl_info, XLogRecord::xl_prev, XLogRecord::xl_rmid, XLogRecord::xl_tot_len, XLogRecord::xl_xid, XLOG_CHECKPOINT_SHUTDOWN, XLOG_PAGE_MAGIC, XLogFileInit(), XLogPageHeaderData::xlp_info, XLP_LONG_HEADER, XLogPageHeaderData::xlp_magic, XLogPageHeaderData::xlp_pageaddr, XLogLongPageHeaderData::xlp_seg_size, XLogLongPageHeaderData::xlp_sysid, XLogPageHeaderData::xlp_tli, XLogLongPageHeaderData::xlp_xlog_blcksz, and XLR_BLOCK_ID_DATA_SHORT.

Referenced by BootstrapModeMain().

◆ CalculateCheckpointSegments()

static void CalculateCheckpointSegments ( void  )
static

Definition at line 2162 of file xlog.c.

2163{
2164 double target;
2165
2166 /*-------
2167 * Calculate the distance at which to trigger a checkpoint, to avoid
2168 * exceeding max_wal_size_mb. This is based on two assumptions:
2169 *
2170 * a) we keep WAL for only one checkpoint cycle (prior to PG11 we kept
2171 * WAL for two checkpoint cycles to allow us to recover from the
2172 * secondary checkpoint if the first checkpoint failed, though we
2173 * only did this on the primary anyway, not on standby. Keeping just
2174 * one checkpoint simplifies processing and reduces disk space in
2175 * many smaller databases.)
2176 * b) during checkpoint, we consume checkpoint_completion_target *
2177 * number of segments consumed between checkpoints.
2178 *-------
2179 */
2180 target = (double) ConvertToXSegs(max_wal_size_mb, wal_segment_size) /
2182
2183 /* round down */
2184 CheckPointSegments = (int) target;
2185
2186 if (CheckPointSegments < 1)
2188}
#define ConvertToXSegs(x, segsize)
Definition: xlog.c:603
int CheckPointSegments
Definition: xlog.c:156

References CheckPointCompletionTarget, CheckPointSegments, ConvertToXSegs, max_wal_size_mb, and wal_segment_size.

Referenced by assign_checkpoint_completion_target(), assign_max_wal_size(), and ReadControlFile().

◆ check_max_slot_wal_keep_size()

bool check_max_slot_wal_keep_size ( int *  newval,
void **  extra,
GucSource  source 
)

Definition at line 2223 of file xlog.c.

2224{
2225 if (IsBinaryUpgrade && *newval != -1)
2226 {
2227 GUC_check_errdetail("\"%s\" must be set to -1 during binary upgrade mode.",
2228 "max_slot_wal_keep_size");
2229 return false;
2230 }
2231
2232 return true;
2233}
bool IsBinaryUpgrade
Definition: globals.c:120
#define GUC_check_errdetail
Definition: guc.h:476

References GUC_check_errdetail, IsBinaryUpgrade, and newval.

◆ check_wal_buffers()

bool check_wal_buffers ( int *  newval,
void **  extra,
GucSource  source 
)

Definition at line 4637 of file xlog.c.

4638{
4639 /*
4640 * -1 indicates a request for auto-tune.
4641 */
4642 if (*newval == -1)
4643 {
4644 /*
4645 * If we haven't yet changed the boot_val default of -1, just let it
4646 * be. We'll fix it when XLOGShmemSize is called.
4647 */
4648 if (XLOGbuffers == -1)
4649 return true;
4650
4651 /* Otherwise, substitute the auto-tune value */
4653 }
4654
4655 /*
4656 * We clamp manually-set values to at least 4 blocks. Prior to PostgreSQL
4657 * 9.1, a minimum of 4 was enforced by guc.c, but since that is no longer
4658 * the case, we just silently treat such values as a request for the
4659 * minimum. (We could throw an error instead, but that doesn't seem very
4660 * helpful.)
4661 */
4662 if (*newval < 4)
4663 *newval = 4;
4664
4665 return true;
4666}
static int XLOGChooseNumBuffers(void)
Definition: xlog.c:4621
int XLOGbuffers
Definition: xlog.c:117

References newval, XLOGbuffers, and XLOGChooseNumBuffers().

◆ check_wal_consistency_checking()

bool check_wal_consistency_checking ( char **  newval,
void **  extra,
GucSource  source 
)

Definition at line 4672 of file xlog.c.

4673{
4674 char *rawstring;
4675 List *elemlist;
4676 ListCell *l;
4677 bool newwalconsistency[RM_MAX_ID + 1];
4678
4679 /* Initialize the array */
4680 MemSet(newwalconsistency, 0, (RM_MAX_ID + 1) * sizeof(bool));
4681
4682 /* Need a modifiable copy of string */
4683 rawstring = pstrdup(*newval);
4684
4685 /* Parse string into list of identifiers */
4686 if (!SplitIdentifierString(rawstring, ',', &elemlist))
4687 {
4688 /* syntax error in list */
4689 GUC_check_errdetail("List syntax is invalid.");
4690 pfree(rawstring);
4691 list_free(elemlist);
4692 return false;
4693 }
4694
4695 foreach(l, elemlist)
4696 {
4697 char *tok = (char *) lfirst(l);
4698 int rmid;
4699
4700 /* Check for 'all'. */
4701 if (pg_strcasecmp(tok, "all") == 0)
4702 {
4703 for (rmid = 0; rmid <= RM_MAX_ID; rmid++)
4704 if (RmgrIdExists(rmid) && GetRmgr(rmid).rm_mask != NULL)
4705 newwalconsistency[rmid] = true;
4706 }
4707 else
4708 {
4709 /* Check if the token matches any known resource manager. */
4710 bool found = false;
4711
4712 for (rmid = 0; rmid <= RM_MAX_ID; rmid++)
4713 {
4714 if (RmgrIdExists(rmid) && GetRmgr(rmid).rm_mask != NULL &&
4715 pg_strcasecmp(tok, GetRmgr(rmid).rm_name) == 0)
4716 {
4717 newwalconsistency[rmid] = true;
4718 found = true;
4719 break;
4720 }
4721 }
4722 if (!found)
4723 {
4724 /*
4725 * During startup, it might be a not-yet-loaded custom
4726 * resource manager. Defer checking until
4727 * InitializeWalConsistencyChecking().
4728 */
4730 {
4732 }
4733 else
4734 {
4735 GUC_check_errdetail("Unrecognized key word: \"%s\".", tok);
4736 pfree(rawstring);
4737 list_free(elemlist);
4738 return false;
4739 }
4740 }
4741 }
4742 }
4743
4744 pfree(rawstring);
4745 list_free(elemlist);
4746
4747 /* assign new value */
4748 *extra = guc_malloc(ERROR, (RM_MAX_ID + 1) * sizeof(bool));
4749 memcpy(*extra, newwalconsistency, (RM_MAX_ID + 1) * sizeof(bool));
4750 return true;
4751}
#define ERROR
Definition: elog.h:39
void * guc_malloc(int elevel, size_t size)
Definition: guc.c:638
void list_free(List *list)
Definition: list.c:1546
char * pstrdup(const char *in)
Definition: mcxt.c:1696
bool process_shared_preload_libraries_done
Definition: miscinit.c:1835
#define lfirst(lc)
Definition: pg_list.h:172
int pg_strcasecmp(const char *s1, const char *s2)
Definition: pgstrcasecmp.c:36
#define RM_MAX_ID
Definition: rmgr.h:33
Definition: pg_list.h:54
void(* rm_mask)(char *pagedata, BlockNumber blkno)
bool SplitIdentifierString(char *rawstring, char separator, List **namelist)
Definition: varlena.c:3432
static bool check_wal_consistency_checking_deferred
Definition: xlog.c:166
static RmgrData GetRmgr(RmgrId rmid)
static bool RmgrIdExists(RmgrId rmid)

References check_wal_consistency_checking_deferred, ERROR, GetRmgr(), GUC_check_errdetail, guc_malloc(), lfirst, list_free(), MemSet, newval, pfree(), pg_strcasecmp(), process_shared_preload_libraries_done, pstrdup(), RmgrData::rm_mask, RM_MAX_ID, RmgrIdExists(), and SplitIdentifierString().

◆ check_wal_segment_size()

bool check_wal_segment_size ( int *  newval,
void **  extra,
GucSource  source 
)

Definition at line 2205 of file xlog.c.

2206{
2208 {
2209 GUC_check_errdetail("The WAL segment size must be a power of two between 1 MB and 1 GB.");
2210 return false;
2211 }
2212
2213 return true;
2214}
#define IsValidWalSegSize(size)
Definition: xlog_internal.h:96

References GUC_check_errdetail, IsValidWalSegSize, and newval.

◆ CheckPointGuts()

static void CheckPointGuts ( XLogRecPtr  checkPointRedo,
int  flags 
)
static

Definition at line 7510 of file xlog.c.

7511{
7517
7518 /* Write out all dirty data in SLRUs and the main buffer pool */
7519 TRACE_POSTGRESQL_BUFFER_CHECKPOINT_START(flags);
7526 CheckPointBuffers(flags);
7527
7528 /* Perform all queued up fsyncs */
7529 TRACE_POSTGRESQL_BUFFER_CHECKPOINT_SYNC_START();
7533 TRACE_POSTGRESQL_BUFFER_CHECKPOINT_DONE();
7534
7535 /* We deliberately delay 2PC checkpointing as long as possible */
7536 CheckPointTwoPhase(checkPointRedo);
7537}
TimestampTz GetCurrentTimestamp(void)
Definition: timestamp.c:1644
void CheckPointBuffers(int flags)
Definition: bufmgr.c:3710
void CheckPointCLOG(void)
Definition: clog.c:937
void CheckPointCommitTs(void)
Definition: commit_ts.c:820
void CheckPointMultiXact(void)
Definition: multixact.c:2304
void CheckPointReplicationOrigin(void)
Definition: origin.c:577
void CheckPointPredicate(void)
Definition: predicate.c:1041
void CheckPointRelationMap(void)
Definition: relmapper.c:611
void CheckPointLogicalRewriteHeap(void)
Definition: rewriteheap.c:1155
void CheckPointReplicationSlots(bool is_shutdown)
Definition: slot.c:1867
void CheckPointSnapBuild(void)
Definition: snapbuild.c:1922
TimestampTz ckpt_write_t
Definition: xlog.h:162
TimestampTz ckpt_sync_end_t
Definition: xlog.h:164
TimestampTz ckpt_sync_t
Definition: xlog.h:163
void CheckPointSUBTRANS(void)
Definition: subtrans.c:355
void ProcessSyncRequests(void)
Definition: sync.c:286
void CheckPointTwoPhase(XLogRecPtr redo_horizon)
Definition: twophase.c:1822
CheckpointStatsData CheckpointStats
Definition: xlog.c:209
#define CHECKPOINT_IS_SHUTDOWN
Definition: xlog.h:139

References CHECKPOINT_IS_SHUTDOWN, CheckPointBuffers(), CheckPointCLOG(), CheckPointCommitTs(), CheckPointLogicalRewriteHeap(), CheckPointMultiXact(), CheckPointPredicate(), CheckPointRelationMap(), CheckPointReplicationOrigin(), CheckPointReplicationSlots(), CheckPointSnapBuild(), CheckpointStats, CheckPointSUBTRANS(), CheckPointTwoPhase(), CheckpointStatsData::ckpt_sync_end_t, CheckpointStatsData::ckpt_sync_t, CheckpointStatsData::ckpt_write_t, GetCurrentTimestamp(), and ProcessSyncRequests().

Referenced by CreateCheckPoint(), and CreateRestartPoint().

◆ CheckRequiredParameterValues()

static void CheckRequiredParameterValues ( void  )
static

Definition at line 5385 of file xlog.c.

5386{
5387 /*
5388 * For archive recovery, the WAL must be generated with at least 'replica'
5389 * wal_level.
5390 */
5392 {
5393 ereport(FATAL,
5394 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
5395 errmsg("WAL was generated with \"wal_level=minimal\", cannot continue recovering"),
5396 errdetail("This happens if you temporarily set \"wal_level=minimal\" on the server."),
5397 errhint("Use a backup taken after setting \"wal_level\" to higher than \"minimal\".")));
5398 }
5399
5400 /*
5401 * For Hot Standby, the WAL must be generated with 'replica' mode, and we
5402 * must have at least as many backend slots as the primary.
5403 */
5405 {
5406 /* We ignore autovacuum_max_workers when we make this test. */
5407 RecoveryRequiresIntParameter("max_connections",
5410 RecoveryRequiresIntParameter("max_worker_processes",
5413 RecoveryRequiresIntParameter("max_wal_senders",
5416 RecoveryRequiresIntParameter("max_prepared_transactions",
5419 RecoveryRequiresIntParameter("max_locks_per_transaction",
5422 }
5423}
int errdetail(const char *fmt,...)
Definition: elog.c:1203
int errhint(const char *fmt,...)
Definition: elog.c:1317
int errcode(int sqlerrcode)
Definition: elog.c:853
#define FATAL
Definition: elog.h:41
int MaxConnections
Definition: globals.c:142
int max_worker_processes
Definition: globals.c:143
int max_locks_per_xact
Definition: lock.c:52
int max_worker_processes
Definition: pg_control.h:181
int max_locks_per_xact
Definition: pg_control.h:184
int max_prepared_xacts
Definition: pg_control.h:183
int max_prepared_xacts
Definition: twophase.c:115
int max_wal_senders
Definition: walsender.c:121
bool EnableHotStandby
Definition: xlog.c:121
@ WAL_LEVEL_MINIMAL
Definition: xlog.h:74
bool ArchiveRecoveryRequested
Definition: xlogrecovery.c:137
void RecoveryRequiresIntParameter(const char *param_name, int currValue, int minValue)

References ArchiveRecoveryRequested, ControlFile, EnableHotStandby, ereport, errcode(), errdetail(), errhint(), errmsg(), FATAL, max_locks_per_xact, ControlFileData::max_locks_per_xact, max_prepared_xacts, ControlFileData::max_prepared_xacts, max_wal_senders, ControlFileData::max_wal_senders, max_worker_processes, ControlFileData::max_worker_processes, MaxConnections, ControlFileData::MaxConnections, RecoveryRequiresIntParameter(), ControlFileData::wal_level, and WAL_LEVEL_MINIMAL.

Referenced by StartupXLOG(), and xlog_redo().

◆ CheckXLogRemoved()

void CheckXLogRemoved ( XLogSegNo  segno,
TimeLineID  tli 
)

Definition at line 3727 of file xlog.c.

3728{
3729 int save_errno = errno;
3730 XLogSegNo lastRemovedSegNo;
3731
3733 lastRemovedSegNo = XLogCtl->lastRemovedSegNo;
3735
3736 if (segno <= lastRemovedSegNo)
3737 {
3738 char filename[MAXFNAMELEN];
3739
3741 errno = save_errno;
3742 ereport(ERROR,
3744 errmsg("requested WAL segment %s has already been removed",
3745 filename)));
3746 }
3747 errno = save_errno;
3748}
static char * filename
Definition: pg_dumpall.c:119
XLogSegNo lastRemovedSegNo
Definition: xlog.c:461
uint64 XLogSegNo
Definition: xlogdefs.h:48

References ereport, errcode_for_file_access(), errmsg(), ERROR, filename, XLogCtlData::info_lck, XLogCtlData::lastRemovedSegNo, MAXFNAMELEN, SpinLockAcquire, SpinLockRelease, wal_segment_size, XLogCtl, and XLogFileName().

Referenced by logical_read_xlog_page(), perform_base_backup(), and XLogSendPhysical().

◆ CleanupAfterArchiveRecovery()

static void CleanupAfterArchiveRecovery ( TimeLineID  EndOfLogTLI,
XLogRecPtr  EndOfLog,
TimeLineID  newTLI 
)
static

Definition at line 5289 of file xlog.c.

5291{
5292 /*
5293 * Execute the recovery_end_command, if any.
5294 */
5295 if (recoveryEndCommand && strcmp(recoveryEndCommand, "") != 0)
5297 "recovery_end_command",
5298 true,
5299 WAIT_EVENT_RECOVERY_END_COMMAND);
5300
5301 /*
5302 * We switched to a new timeline. Clean up segments on the old timeline.
5303 *
5304 * If there are any higher-numbered segments on the old timeline, remove
5305 * them. They might contain valid WAL, but they might also be
5306 * pre-allocated files containing garbage. In any case, they are not part
5307 * of the new timeline's history so we don't need them.
5308 */
5309 RemoveNonParentXlogFiles(EndOfLog, newTLI);
5310
5311 /*
5312 * If the switch happened in the middle of a segment, what to do with the
5313 * last, partial segment on the old timeline? If we don't archive it, and
5314 * the server that created the WAL never archives it either (e.g. because
5315 * it was hit by a meteor), it will never make it to the archive. That's
5316 * OK from our point of view, because the new segment that we created with
5317 * the new TLI contains all the WAL from the old timeline up to the switch
5318 * point. But if you later try to do PITR to the "missing" WAL on the old
5319 * timeline, recovery won't find it in the archive. It's physically
5320 * present in the new file with new TLI, but recovery won't look there
5321 * when it's recovering to the older timeline. On the other hand, if we
5322 * archive the partial segment, and the original server on that timeline
5323 * is still running and archives the completed version of the same segment
5324 * later, it will fail. (We used to do that in 9.4 and below, and it
5325 * caused such problems).
5326 *
5327 * As a compromise, we rename the last segment with the .partial suffix,
5328 * and archive it. Archive recovery will never try to read .partial
5329 * segments, so they will normally go unused. But in the odd PITR case,
5330 * the administrator can copy them manually to the pg_wal directory
5331 * (removing the suffix). They can be useful in debugging, too.
5332 *
5333 * If a .done or .ready file already exists for the old timeline, however,
5334 * we had already determined that the segment is complete, so we can let
5335 * it be archived normally. (In particular, if it was restored from the
5336 * archive to begin with, it's expected to have a .done file).
5337 */
5338 if (XLogSegmentOffset(EndOfLog, wal_segment_size) != 0 &&
5340 {
5341 char origfname[MAXFNAMELEN];
5342 XLogSegNo endLogSegNo;
5343
5344 XLByteToPrevSeg(EndOfLog, endLogSegNo, wal_segment_size);
5345 XLogFileName(origfname, EndOfLogTLI, endLogSegNo, wal_segment_size);
5346
5347 if (!XLogArchiveIsReadyOrDone(origfname))
5348 {
5349 char origpath[MAXPGPATH];
5350 char partialfname[MAXFNAMELEN];
5351 char partialpath[MAXPGPATH];
5352
5353 /*
5354 * If we're summarizing WAL, we can't rename the partial file
5355 * until the summarizer finishes with it, else it will fail.
5356 */
5357 if (summarize_wal)
5358 WaitForWalSummarization(EndOfLog);
5359
5360 XLogFilePath(origpath, EndOfLogTLI, endLogSegNo, wal_segment_size);
5361 snprintf(partialfname, MAXFNAMELEN, "%s.partial", origfname);
5362 snprintf(partialpath, MAXPGPATH, "%s.partial", origpath);
5363
5364 /*
5365 * Make sure there's no .done or .ready file for the .partial
5366 * file.
5367 */
5368 XLogArchiveCleanup(partialfname);
5369
5370 durable_rename(origpath, partialpath, ERROR);
5371 XLogArchiveNotify(partialfname);
5372 }
5373 }
5374}
int durable_rename(const char *oldfile, const char *newfile, int elevel)
Definition: fd.c:781
#define MAXPGPATH
#define snprintf
Definition: port.h:238
bool summarize_wal
void WaitForWalSummarization(XLogRecPtr lsn)
void RemoveNonParentXlogFiles(XLogRecPtr switchpoint, TimeLineID newTLI)
Definition: xlog.c:3940
#define XLogArchivingActive()
Definition: xlog.h:99
#define XLByteToPrevSeg(xlrp, logSegNo, wal_segsz_bytes)
static void XLogFilePath(char *path, TimeLineID tli, XLogSegNo logSegNo, int wal_segsz_bytes)
bool XLogArchiveIsReadyOrDone(const char *xlog)
Definition: xlogarchive.c:664
void ExecuteRecoveryCommand(const char *command, const char *commandName, bool failOnSignal, uint32 wait_event_info)
Definition: xlogarchive.c:295
void XLogArchiveNotify(const char *xlog)
Definition: xlogarchive.c:444
void XLogArchiveCleanup(const char *xlog)
Definition: xlogarchive.c:712
char * recoveryEndCommand
Definition: xlogrecovery.c:83

References durable_rename(), ERROR, ExecuteRecoveryCommand(), MAXFNAMELEN, MAXPGPATH, recoveryEndCommand, RemoveNonParentXlogFiles(), snprintf, summarize_wal, WaitForWalSummarization(), wal_segment_size, XLByteToPrevSeg, XLogArchiveCleanup(), XLogArchiveIsReadyOrDone(), XLogArchiveNotify(), XLogArchivingActive, XLogFileName(), XLogFilePath(), and XLogSegmentOffset.

Referenced by StartupXLOG().

◆ CleanupBackupHistory()

static void CleanupBackupHistory ( void  )
static

Definition at line 4161 of file xlog.c.

4162{
4163 DIR *xldir;
4164 struct dirent *xlde;
4165 char path[MAXPGPATH + sizeof(XLOGDIR)];
4166
4167 xldir = AllocateDir(XLOGDIR);
4168
4169 while ((xlde = ReadDir(xldir, XLOGDIR)) != NULL)
4170 {
4172 {
4173 if (XLogArchiveCheckDone(xlde->d_name))
4174 {
4175 elog(DEBUG2, "removing WAL backup history file \"%s\"",
4176 xlde->d_name);
4177 snprintf(path, sizeof(path), XLOGDIR "/%s", xlde->d_name);
4178 unlink(path);
4180 }
4181 }
4182 }
4183
4184 FreeDir(xldir);
4185}
#define DEBUG2
Definition: elog.h:29
int FreeDir(DIR *dir)
Definition: fd.c:2983
DIR * AllocateDir(const char *dirname)
Definition: fd.c:2865
struct dirent * ReadDir(DIR *dir, const char *dirname)
Definition: fd.c:2931
Definition: dirent.c:26
Definition: dirent.h:10
char d_name[MAX_PATH]
Definition: dirent.h:15
#define XLOGDIR
static bool IsBackupHistoryFileName(const char *fname)
bool XLogArchiveCheckDone(const char *xlog)
Definition: xlogarchive.c:565

References AllocateDir(), dirent::d_name, DEBUG2, elog, FreeDir(), IsBackupHistoryFileName(), MAXPGPATH, ReadDir(), snprintf, XLogArchiveCheckDone(), XLogArchiveCleanup(), and XLOGDIR.

Referenced by do_pg_backup_stop().

◆ CopyXLogRecordToWAL()

static void CopyXLogRecordToWAL ( int  write_len,
bool  isLogSwitch,
XLogRecData rdata,
XLogRecPtr  StartPos,
XLogRecPtr  EndPos,
TimeLineID  tli 
)
static

Definition at line 1225 of file xlog.c.

1227{
1228 char *currpos;
1229 int freespace;
1230 int written;
1231 XLogRecPtr CurrPos;
1232 XLogPageHeader pagehdr;
1233
1234 /*
1235 * Get a pointer to the right place in the right WAL buffer to start
1236 * inserting to.
1237 */
1238 CurrPos = StartPos;
1239 currpos = GetXLogBuffer(CurrPos, tli);
1240 freespace = INSERT_FREESPACE(CurrPos);
1241
1242 /*
1243 * there should be enough space for at least the first field (xl_tot_len)
1244 * on this page.
1245 */
1246 Assert(freespace >= sizeof(uint32));
1247
1248 /* Copy record data */
1249 written = 0;
1250 while (rdata != NULL)
1251 {
1252 const char *rdata_data = rdata->data;
1253 int rdata_len = rdata->len;
1254
1255 while (rdata_len > freespace)
1256 {
1257 /*
1258 * Write what fits on this page, and continue on the next page.
1259 */
1260 Assert(CurrPos % XLOG_BLCKSZ >= SizeOfXLogShortPHD || freespace == 0);
1261 memcpy(currpos, rdata_data, freespace);
1262 rdata_data += freespace;
1263 rdata_len -= freespace;
1264 written += freespace;
1265 CurrPos += freespace;
1266
1267 /*
1268 * Get pointer to beginning of next page, and set the xlp_rem_len
1269 * in the page header. Set XLP_FIRST_IS_CONTRECORD.
1270 *
1271 * It's safe to set the contrecord flag and xlp_rem_len without a
1272 * lock on the page. All the other flags were already set when the
1273 * page was initialized, in AdvanceXLInsertBuffer, and we're the
1274 * only backend that needs to set the contrecord flag.
1275 */
1276 currpos = GetXLogBuffer(CurrPos, tli);
1277 pagehdr = (XLogPageHeader) currpos;
1278 pagehdr->xlp_rem_len = write_len - written;
1280
1281 /* skip over the page header */
1282 if (XLogSegmentOffset(CurrPos, wal_segment_size) == 0)
1283 {
1284 CurrPos += SizeOfXLogLongPHD;
1285 currpos += SizeOfXLogLongPHD;
1286 }
1287 else
1288 {
1289 CurrPos += SizeOfXLogShortPHD;
1290 currpos += SizeOfXLogShortPHD;
1291 }
1292 freespace = INSERT_FREESPACE(CurrPos);
1293 }
1294
1295 Assert(CurrPos % XLOG_BLCKSZ >= SizeOfXLogShortPHD || rdata_len == 0);
1296 memcpy(currpos, rdata_data, rdata_len);
1297 currpos += rdata_len;
1298 CurrPos += rdata_len;
1299 freespace -= rdata_len;
1300 written += rdata_len;
1301
1302 rdata = rdata->next;
1303 }
1304 Assert(written == write_len);
1305
1306 /*
1307 * If this was an xlog-switch, it's not enough to write the switch record,
1308 * we also have to consume all the remaining space in the WAL segment. We
1309 * have already reserved that space, but we need to actually fill it.
1310 */
1311 if (isLogSwitch && XLogSegmentOffset(CurrPos, wal_segment_size) != 0)
1312 {
1313 /* An xlog-switch record doesn't contain any data besides the header */
1314 Assert(write_len == SizeOfXLogRecord);
1315
1316 /* Assert that we did reserve the right amount of space */
1318
1319 /* Use up all the remaining space on the current page */
1320 CurrPos += freespace;
1321
1322 /*
1323 * Cause all remaining pages in the segment to be flushed, leaving the
1324 * XLog position where it should be, at the start of the next segment.
1325 * We do this one page at a time, to make sure we don't deadlock
1326 * against ourselves if wal_buffers < wal_segment_size.
1327 */
1328 while (CurrPos < EndPos)
1329 {
1330 /*
1331 * The minimal action to flush the page would be to call
1332 * WALInsertLockUpdateInsertingAt(CurrPos) followed by
1333 * AdvanceXLInsertBuffer(...). The page would be left initialized
1334 * mostly to zeros, except for the page header (always the short
1335 * variant, as this is never a segment's first page).
1336 *
1337 * The large vistas of zeros are good for compressibility, but the
1338 * headers interrupting them every XLOG_BLCKSZ (with values that
1339 * differ from page to page) are not. The effect varies with
1340 * compression tool, but bzip2 for instance compresses about an
1341 * order of magnitude worse if those headers are left in place.
1342 *
1343 * Rather than complicating AdvanceXLInsertBuffer itself (which is
1344 * called in heavily-loaded circumstances as well as this lightly-
1345 * loaded one) with variant behavior, we just use GetXLogBuffer
1346 * (which itself calls the two methods we need) to get the pointer
1347 * and zero most of the page. Then we just zero the page header.
1348 */
1349 currpos = GetXLogBuffer(CurrPos, tli);
1350 MemSet(currpos, 0, SizeOfXLogShortPHD);
1351
1352 CurrPos += XLOG_BLCKSZ;
1353 }
1354 }
1355 else
1356 {
1357 /* Align the end position, so that the next record starts aligned */
1358 CurrPos = MAXALIGN64(CurrPos);
1359 }
1360
1361 if (CurrPos != EndPos)
1362 ereport(PANIC,
1364 errmsg_internal("space reserved for WAL record does not match what was written"));
1365}
uint32_t uint32
Definition: c.h:485
#define MAXALIGN64(LEN)
Definition: c.h:790
int errmsg_internal(const char *fmt,...)
Definition: elog.c:1157
#define ERRCODE_DATA_CORRUPTED
Definition: pg_basebackup.c:41
const char * data
struct XLogRecData * next
#define INSERT_FREESPACE(endptr)
Definition: xlog.c:580
static char * GetXLogBuffer(XLogRecPtr ptr, TimeLineID tli)
Definition: xlog.c:1632
#define XLP_FIRST_IS_CONTRECORD
Definition: xlog_internal.h:74
#define SizeOfXLogShortPHD
Definition: xlog_internal.h:52

References Assert, XLogRecData::data, ereport, errcode(), ERRCODE_DATA_CORRUPTED, errmsg_internal(), GetXLogBuffer(), INSERT_FREESPACE, XLogRecData::len, MAXALIGN64, MemSet, XLogRecData::next, PANIC, SizeOfXLogLongPHD, SizeOfXLogRecord, SizeOfXLogShortPHD, wal_segment_size, XLogSegmentOffset, XLP_FIRST_IS_CONTRECORD, XLogPageHeaderData::xlp_info, and XLogPageHeaderData::xlp_rem_len.

Referenced by XLogInsertRecord().

◆ CreateCheckPoint()

bool CreateCheckPoint ( int  flags)

Definition at line 6889 of file xlog.c.

6890{
6891 bool shutdown;
6892 CheckPoint checkPoint;
6893 XLogRecPtr recptr;
6894 XLogSegNo _logSegNo;
6896 uint32 freespace;
6897 XLogRecPtr PriorRedoPtr;
6898 XLogRecPtr last_important_lsn;
6899 VirtualTransactionId *vxids;
6900 int nvxids;
6901 int oldXLogAllowed = 0;
6902
6903 /*
6904 * An end-of-recovery checkpoint is really a shutdown checkpoint, just
6905 * issued at a different time.
6906 */
6908 shutdown = true;
6909 else
6910 shutdown = false;
6911
6912 /* sanity check */
6913 if (RecoveryInProgress() && (flags & CHECKPOINT_END_OF_RECOVERY) == 0)
6914 elog(ERROR, "can't create a checkpoint during recovery");
6915
6916 /*
6917 * Prepare to accumulate statistics.
6918 *
6919 * Note: because it is possible for log_checkpoints to change while a
6920 * checkpoint proceeds, we always accumulate stats, even if
6921 * log_checkpoints is currently off.
6922 */
6925
6926 /*
6927 * Let smgr prepare for checkpoint; this has to happen outside the
6928 * critical section and before we determine the REDO pointer. Note that
6929 * smgr must not do anything that'd have to be undone if we decide no
6930 * checkpoint is needed.
6931 */
6933
6934 /*
6935 * Use a critical section to force system panic if we have trouble.
6936 */
6938
6939 if (shutdown)
6940 {
6941 LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
6944 LWLockRelease(ControlFileLock);
6945 }
6946
6947 /* Begin filling in the checkpoint WAL record */
6948 MemSet(&checkPoint, 0, sizeof(checkPoint));
6949 checkPoint.time = (pg_time_t) time(NULL);
6950
6951 /*
6952 * For Hot Standby, derive the oldestActiveXid before we fix the redo
6953 * pointer. This allows us to begin accumulating changes to assemble our
6954 * starting snapshot of locks and transactions.
6955 */
6956 if (!shutdown && XLogStandbyInfoActive())
6958 else
6960
6961 /*
6962 * Get location of last important record before acquiring insert locks (as
6963 * GetLastImportantRecPtr() also locks WAL locks).
6964 */
6965 last_important_lsn = GetLastImportantRecPtr();
6966
6967 /*
6968 * If this isn't a shutdown or forced checkpoint, and if there has been no
6969 * WAL activity requiring a checkpoint, skip it. The idea here is to
6970 * avoid inserting duplicate checkpoints when the system is idle.
6971 */
6973 CHECKPOINT_FORCE)) == 0)
6974 {
6975 if (last_important_lsn == ControlFile->checkPoint)
6976 {
6979 (errmsg_internal("checkpoint skipped because system is idle")));
6980 return false;
6981 }
6982 }
6983
6984 /*
6985 * An end-of-recovery checkpoint is created before anyone is allowed to
6986 * write WAL. To allow us to write the checkpoint record, temporarily
6987 * enable XLogInsertAllowed.
6988 */
6989 if (flags & CHECKPOINT_END_OF_RECOVERY)
6990 oldXLogAllowed = LocalSetXLogInsertAllowed();
6991
6993 if (flags & CHECKPOINT_END_OF_RECOVERY)
6995 else
6996 checkPoint.PrevTimeLineID = checkPoint.ThisTimeLineID;
6997
6998 /*
6999 * We must block concurrent insertions while examining insert state.
7000 */
7002
7003 checkPoint.fullPageWrites = Insert->fullPageWrites;
7004 checkPoint.wal_level = wal_level;
7005
7006 if (shutdown)
7007 {
7008 XLogRecPtr curInsert = XLogBytePosToRecPtr(Insert->CurrBytePos);
7009
7010 /*
7011 * Compute new REDO record ptr = location of next XLOG record.
7012 *
7013 * Since this is a shutdown checkpoint, there can't be any concurrent
7014 * WAL insertion.
7015 */
7016 freespace = INSERT_FREESPACE(curInsert);
7017 if (freespace == 0)
7018 {
7019 if (XLogSegmentOffset(curInsert, wal_segment_size) == 0)
7020 curInsert += SizeOfXLogLongPHD;
7021 else
7022 curInsert += SizeOfXLogShortPHD;
7023 }
7024 checkPoint.redo = curInsert;
7025
7026 /*
7027 * Here we update the shared RedoRecPtr for future XLogInsert calls;
7028 * this must be done while holding all the insertion locks.
7029 *
7030 * Note: if we fail to complete the checkpoint, RedoRecPtr will be
7031 * left pointing past where it really needs to point. This is okay;
7032 * the only consequence is that XLogInsert might back up whole buffers
7033 * that it didn't really need to. We can't postpone advancing
7034 * RedoRecPtr because XLogInserts that happen while we are dumping
7035 * buffers must assume that their buffer changes are not included in
7036 * the checkpoint.
7037 */
7038 RedoRecPtr = XLogCtl->Insert.RedoRecPtr = checkPoint.redo;
7039 }
7040
7041 /*
7042 * Now we can release the WAL insertion locks, allowing other xacts to
7043 * proceed while we are flushing disk buffers.
7044 */
7046
7047 /*
7048 * If this is an online checkpoint, we have not yet determined the redo
7049 * point. We do so now by inserting the special XLOG_CHECKPOINT_REDO
7050 * record; the LSN at which it starts becomes the new redo pointer. We
7051 * don't do this for a shutdown checkpoint, because in that case no WAL
7052 * can be written between the redo point and the insertion of the
7053 * checkpoint record itself, so the checkpoint record itself serves to
7054 * mark the redo point.
7055 */
7056 if (!shutdown)
7057 {
7058 /* Include WAL level in record for WAL summarizer's benefit. */
7060 XLogRegisterData((char *) &wal_level, sizeof(wal_level));
7061 (void) XLogInsert(RM_XLOG_ID, XLOG_CHECKPOINT_REDO);
7062
7063 /*
7064 * XLogInsertRecord will have updated XLogCtl->Insert.RedoRecPtr in
7065 * shared memory and RedoRecPtr in backend-local memory, but we need
7066 * to copy that into the record that will be inserted when the
7067 * checkpoint is complete.
7068 */
7069 checkPoint.redo = RedoRecPtr;
7070 }
7071
7072 /* Update the info_lck-protected copy of RedoRecPtr as well */
7074 XLogCtl->RedoRecPtr = checkPoint.redo;
7076
7077 /*
7078 * If enabled, log checkpoint start. We postpone this until now so as not
7079 * to log anything if we decided to skip the checkpoint.
7080 */
7081 if (log_checkpoints)
7082 LogCheckpointStart(flags, false);
7083
7084 /* Update the process title */
7085 update_checkpoint_display(flags, false, false);
7086
7087 TRACE_POSTGRESQL_CHECKPOINT_START(flags);
7088
7089 /*
7090 * Get the other info we need for the checkpoint record.
7091 *
7092 * We don't need to save oldestClogXid in the checkpoint, it only matters
7093 * for the short period in which clog is being truncated, and if we crash
7094 * during that we'll redo the clog truncation and fix up oldestClogXid
7095 * there.
7096 */
7097 LWLockAcquire(XidGenLock, LW_SHARED);
7098 checkPoint.nextXid = TransamVariables->nextXid;
7099 checkPoint.oldestXid = TransamVariables->oldestXid;
7101 LWLockRelease(XidGenLock);
7102
7103 LWLockAcquire(CommitTsLock, LW_SHARED);
7106 LWLockRelease(CommitTsLock);
7107
7108 LWLockAcquire(OidGenLock, LW_SHARED);
7109 checkPoint.nextOid = TransamVariables->nextOid;
7110 if (!shutdown)
7111 checkPoint.nextOid += TransamVariables->oidCount;
7112 LWLockRelease(OidGenLock);
7113
7114 MultiXactGetCheckptMulti(shutdown,
7115 &checkPoint.nextMulti,
7116 &checkPoint.nextMultiOffset,
7117 &checkPoint.oldestMulti,
7118 &checkPoint.oldestMultiDB);
7119
7120 /*
7121 * Having constructed the checkpoint record, ensure all shmem disk buffers
7122 * and commit-log buffers are flushed to disk.
7123 *
7124 * This I/O could fail for various reasons. If so, we will fail to
7125 * complete the checkpoint, but there is no reason to force a system
7126 * panic. Accordingly, exit critical section while doing it.
7127 */
7129
7130 /*
7131 * In some cases there are groups of actions that must all occur on one
7132 * side or the other of a checkpoint record. Before flushing the
7133 * checkpoint record we must explicitly wait for any backend currently
7134 * performing those groups of actions.
7135 *
7136 * One example is end of transaction, so we must wait for any transactions
7137 * that are currently in commit critical sections. If an xact inserted
7138 * its commit record into XLOG just before the REDO point, then a crash
7139 * restart from the REDO point would not replay that record, which means
7140 * that our flushing had better include the xact's update of pg_xact. So
7141 * we wait till he's out of his commit critical section before proceeding.
7142 * See notes in RecordTransactionCommit().
7143 *
7144 * Because we've already released the insertion locks, this test is a bit
7145 * fuzzy: it is possible that we will wait for xacts we didn't really need
7146 * to wait for. But the delay should be short and it seems better to make
7147 * checkpoint take a bit longer than to hold off insertions longer than
7148 * necessary. (In fact, the whole reason we have this issue is that xact.c
7149 * does commit record XLOG insertion and clog update as two separate steps
7150 * protected by different locks, but again that seems best on grounds of
7151 * minimizing lock contention.)
7152 *
7153 * A transaction that has not yet set delayChkptFlags when we look cannot
7154 * be at risk, since it has not inserted its commit record yet; and one
7155 * that's already cleared it is not at risk either, since it's done fixing
7156 * clog and we will correctly flush the update below. So we cannot miss
7157 * any xacts we need to wait for.
7158 */
7160 if (nvxids > 0)
7161 {
7162 do
7163 {
7164 /*
7165 * Keep absorbing fsync requests while we wait. There could even
7166 * be a deadlock if we don't, if the process that prevents the
7167 * checkpoint is trying to add a request to the queue.
7168 */
7170
7171 pgstat_report_wait_start(WAIT_EVENT_CHECKPOINT_DELAY_START);
7172 pg_usleep(10000L); /* wait for 10 msec */
7174 } while (HaveVirtualXIDsDelayingChkpt(vxids, nvxids,
7176 }
7177 pfree(vxids);
7178
7179 CheckPointGuts(checkPoint.redo, flags);
7180
7182 if (nvxids > 0)
7183 {
7184 do
7185 {
7187
7188 pgstat_report_wait_start(WAIT_EVENT_CHECKPOINT_DELAY_COMPLETE);
7189 pg_usleep(10000L); /* wait for 10 msec */
7191 } while (HaveVirtualXIDsDelayingChkpt(vxids, nvxids,
7193 }
7194 pfree(vxids);
7195
7196 /*
7197 * Take a snapshot of running transactions and write this to WAL. This
7198 * allows us to reconstruct the state of running transactions during
7199 * archive recovery, if required. Skip, if this info disabled.
7200 *
7201 * If we are shutting down, or Startup process is completing crash
7202 * recovery we don't need to write running xact data.
7203 */
7204 if (!shutdown && XLogStandbyInfoActive())
7206
7208
7209 /*
7210 * Now insert the checkpoint record into XLOG.
7211 */
7213 XLogRegisterData((char *) (&checkPoint), sizeof(checkPoint));
7214 recptr = XLogInsert(RM_XLOG_ID,
7215 shutdown ? XLOG_CHECKPOINT_SHUTDOWN :
7217
7218 XLogFlush(recptr);
7219
7220 /*
7221 * We mustn't write any new WAL after a shutdown checkpoint, or it will be
7222 * overwritten at next startup. No-one should even try, this just allows
7223 * sanity-checking. In the case of an end-of-recovery checkpoint, we want
7224 * to just temporarily disable writing until the system has exited
7225 * recovery.
7226 */
7227 if (shutdown)
7228 {
7229 if (flags & CHECKPOINT_END_OF_RECOVERY)
7230 LocalXLogInsertAllowed = oldXLogAllowed;
7231 else
7232 LocalXLogInsertAllowed = 0; /* never again write WAL */
7233 }
7234
7235 /*
7236 * We now have ProcLastRecPtr = start of actual checkpoint record, recptr
7237 * = end of actual checkpoint record.
7238 */
7239 if (shutdown && checkPoint.redo != ProcLastRecPtr)
7240 ereport(PANIC,
7241 (errmsg("concurrent write-ahead log activity while database system is shutting down")));
7242
7243 /*
7244 * Remember the prior checkpoint's redo ptr for
7245 * UpdateCheckPointDistanceEstimate()
7246 */
7247 PriorRedoPtr = ControlFile->checkPointCopy.redo;
7248
7249 /*
7250 * Update the control file.
7251 */
7252 LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
7253 if (shutdown)
7256 ControlFile->checkPointCopy = checkPoint;
7257 /* crash recovery should always recover to the end of WAL */
7260
7261 /*
7262 * Persist unloggedLSN value. It's reset on crash recovery, so this goes
7263 * unused on non-shutdown checkpoints, but seems useful to store it always
7264 * for debugging purposes.
7265 */
7267
7269 LWLockRelease(ControlFileLock);
7270
7271 /* Update shared-memory copy of checkpoint XID/epoch */
7273 XLogCtl->ckptFullXid = checkPoint.nextXid;
7275
7276 /*
7277 * We are now done with critical updates; no need for system panic if we
7278 * have trouble while fooling with old log segments.
7279 */
7281
7282 /*
7283 * WAL summaries end when the next XLOG_CHECKPOINT_REDO or
7284 * XLOG_CHECKPOINT_SHUTDOWN record is reached. This is the first point
7285 * where (a) we're not inside of a critical section and (b) we can be
7286 * certain that the relevant record has been flushed to disk, which must
7287 * happen before it can be summarized.
7288 *
7289 * If this is a shutdown checkpoint, then this happens reasonably
7290 * promptly: we've only just inserted and flushed the
7291 * XLOG_CHECKPOINT_SHUTDOWN record. If this is not a shutdown checkpoint,
7292 * then this might not be very prompt at all: the XLOG_CHECKPOINT_REDO
7293 * record was written before we began flushing data to disk, and that
7294 * could be many minutes ago at this point. However, we don't XLogFlush()
7295 * after inserting that record, so we're not guaranteed that it's on disk
7296 * until after the above call that flushes the XLOG_CHECKPOINT_ONLINE
7297 * record.
7298 */
7300
7301 /*
7302 * Let smgr do post-checkpoint cleanup (eg, deleting old files).
7303 */
7305
7306 /*
7307 * Update the average distance between checkpoints if the prior checkpoint
7308 * exists.
7309 */
7310 if (PriorRedoPtr != InvalidXLogRecPtr)
7312
7313 /*
7314 * Delete old log files, those no longer needed for last checkpoint to
7315 * prevent the disk holding the xlog from growing full.
7316 */
7318 KeepLogSeg(recptr, &_logSegNo);
7320 _logSegNo, InvalidOid,
7322 {
7323 /*
7324 * Some slots have been invalidated; recalculate the old-segment
7325 * horizon, starting again from RedoRecPtr.
7326 */
7328 KeepLogSeg(recptr, &_logSegNo);
7329 }
7330 _logSegNo--;
7331 RemoveOldXlogFiles(_logSegNo, RedoRecPtr, recptr,
7332 checkPoint.ThisTimeLineID);
7333
7334 /*
7335 * Make more log segments if needed. (Do this after recycling old log
7336 * segments, since that may supply some of the needed files.)
7337 */
7338 if (!shutdown)
7339 PreallocXlogFiles(recptr, checkPoint.ThisTimeLineID);
7340
7341 /*
7342 * Truncate pg_subtrans if possible. We can throw away all data before
7343 * the oldest XMIN of any running transaction. No future transaction will
7344 * attempt to reference any pg_subtrans entry older than that (see Asserts
7345 * in subtrans.c). During recovery, though, we mustn't do this because
7346 * StartupSUBTRANS hasn't been called yet.
7347 */
7348 if (!RecoveryInProgress())
7350
7351 /* Real work is done; log and update stats. */
7352 LogCheckpointEnd(false);
7353
7354 /* Reset the process title */
7355 update_checkpoint_display(flags, false, true);
7356
7357 TRACE_POSTGRESQL_CHECKPOINT_DONE(CheckpointStats.ckpt_bufs_written,
7358 NBuffers,
7362
7363 return true;
7364}
static uint64 pg_atomic_read_membarrier_u64(volatile pg_atomic_uint64 *ptr)
Definition: atomics.h:476
void AbsorbSyncRequests(void)
int NBuffers
Definition: globals.c:141
@ LW_SHARED
Definition: lwlock.h:115
#define START_CRIT_SECTION()
Definition: miscadmin.h:149
#define END_CRIT_SECTION()
Definition: miscadmin.h:151
void MultiXactGetCheckptMulti(bool is_shutdown, MultiXactId *nextMulti, MultiXactOffset *nextMultiOffset, MultiXactId *oldestMulti, Oid *oldestMultiDB)
Definition: multixact.c:2282
#define XLOG_CHECKPOINT_REDO
Definition: pg_control.h:82
@ DB_SHUTDOWNING
Definition: pg_control.h:94
@ DB_SHUTDOWNED
Definition: pg_control.h:92
#define XLOG_CHECKPOINT_ONLINE
Definition: pg_control.h:69
#define InvalidOid
Definition: postgres_ext.h:36
#define DELAY_CHKPT_START
Definition: proc.h:119
#define DELAY_CHKPT_COMPLETE
Definition: proc.h:120
TransactionId GetOldestActiveTransactionId(void)
Definition: procarray.c:2880
TransactionId GetOldestTransactionIdConsideredRunning(void)
Definition: procarray.c:2034
bool HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids, int nvxids, int type)
Definition: procarray.c:3089
VirtualTransactionId * GetVirtualXIDsDelayingChkpt(int *nvxids, int type)
Definition: procarray.c:3043
void pg_usleep(long microsec)
Definition: signal.c:53
bool InvalidateObsoleteReplicationSlots(ReplicationSlotInvalidationCause cause, XLogSegNo oldestSegno, Oid dboid, TransactionId snapshotConflictHorizon)
Definition: slot.c:1811
@ RS_INVAL_WAL_REMOVED
Definition: slot.h:54
XLogRecPtr LogStandbySnapshot(void)
Definition: standby.c:1281
TimestampTz ckpt_start_t
Definition: xlog.h:161
int ckpt_segs_removed
Definition: xlog.h:171
int ckpt_segs_added
Definition: xlog.h:170
int ckpt_bufs_written
Definition: xlog.h:167
int ckpt_segs_recycled
Definition: xlog.h:172
XLogRecPtr minRecoveryPoint
Definition: pg_control.h:168
XLogRecPtr unloggedLSN
Definition: pg_control.h:137
TimeLineID minRecoveryPointTLI
Definition: pg_control.h:169
TransactionId oldestCommitTsXid
Definition: transam.h:232
TransactionId newestCommitTsXid
Definition: transam.h:233
TransactionId oldestXid
Definition: transam.h:222
FullTransactionId ckptFullXid
Definition: xlog.c:457
TimeLineID InsertTimeLineID
Definition: xlog.c:509
XLogRecPtr RedoRecPtr
Definition: xlog.c:456
TimeLineID PrevTimeLineID
Definition: xlog.c:510
pg_atomic_uint64 unloggedLSN
Definition: xlog.c:464
XLogRecPtr RedoRecPtr
Definition: xlog.c:430
void TruncateSUBTRANS(TransactionId oldestXact)
Definition: subtrans.c:411
void SyncPreCheckpoint(void)
Definition: sync.c:177
void SyncPostCheckpoint(void)
Definition: sync.c:202
void WakeupWalSummarizer(void)
XLogRecPtr ProcLastRecPtr
Definition: xlog.c:253
bool RecoveryInProgress(void)
Definition: xlog.c:6334
static void WALInsertLockRelease(void)
Definition: xlog.c:1445
static XLogRecPtr XLogBytePosToRecPtr(uint64 bytepos)
Definition: xlog.c:1858
static void WALInsertLockAcquireExclusive(void)
Definition: xlog.c:1416
static void UpdateControlFile(void)
Definition: xlog.c:4559
static void RemoveOldXlogFiles(XLogSegNo segno, XLogRecPtr lastredoptr, XLogRecPtr endptr, TimeLineID insertTLI)
Definition: xlog.c:3865
static void LogCheckpointStart(int flags, bool restartpoint)
Definition: xlog.c:6649
static XLogRecPtr RedoRecPtr
Definition: xlog.c:273
static void LogCheckpointEnd(bool restartpoint)
Definition: xlog.c:6681
static void PreallocXlogFiles(XLogRecPtr endptr, TimeLineID tli)
Definition: xlog.c:3690
bool log_checkpoints
Definition: xlog.c:129
static void KeepLogSeg(XLogRecPtr recptr, XLogSegNo *logSegNo)
Definition: xlog.c:7953
static int LocalSetXLogInsertAllowed(void)
Definition: xlog.c:6422
XLogRecPtr GetLastImportantRecPtr(void)
Definition: xlog.c:6556
static void UpdateCheckPointDistanceEstimate(uint64 nbytes)
Definition: xlog.c:6786
static int LocalXLogInsertAllowed
Definition: xlog.c:236
void XLogFlush(XLogRecPtr record)
Definition: xlog.c:2802
static void CheckPointGuts(XLogRecPtr checkPointRedo, int flags)
Definition: xlog.c:7510
static void update_checkpoint_display(int flags, bool restartpoint, bool reset)
Definition: xlog.c:6824
#define CHECKPOINT_END_OF_RECOVERY
Definition: xlog.h:140
#define CHECKPOINT_FORCE
Definition: xlog.h:142
#define XLogStandbyInfoActive()
Definition: xlog.h:123
#define XLByteToSeg(xlrp, logSegNo, wal_segsz_bytes)
XLogRecPtr XLogInsert(RmgrId rmid, uint8 info)
Definition: xloginsert.c:474
void XLogRegisterData(const char *data, uint32 len)
Definition: xloginsert.c:364
void XLogBeginInsert(void)
Definition: xloginsert.c:149

References AbsorbSyncRequests(), ControlFileData::checkPoint, CHECKPOINT_END_OF_RECOVERY, CHECKPOINT_FORCE, CHECKPOINT_IS_SHUTDOWN, ControlFileData::checkPointCopy, CheckPointGuts(), CheckpointStats, CheckpointStatsData::ckpt_bufs_written, CheckpointStatsData::ckpt_segs_added, CheckpointStatsData::ckpt_segs_recycled, CheckpointStatsData::ckpt_segs_removed, CheckpointStatsData::ckpt_start_t, XLogCtlData::ckptFullXid, ControlFile, DB_SHUTDOWNED, DB_SHUTDOWNING, DEBUG1, DELAY_CHKPT_COMPLETE, DELAY_CHKPT_START, elog, END_CRIT_SECTION, ereport, errmsg(), errmsg_internal(), ERROR, CheckPoint::fullPageWrites, GetCurrentTimestamp(), GetLastImportantRecPtr(), GetOldestActiveTransactionId(), GetOldestTransactionIdConsideredRunning(), GetVirtualXIDsDelayingChkpt(), HaveVirtualXIDsDelayingChkpt(), XLogCtlData::info_lck, XLogCtlData::Insert, Insert(), INSERT_FREESPACE, XLogCtlData::InsertTimeLineID, InvalidateObsoleteReplicationSlots(), InvalidOid, InvalidTransactionId, InvalidXLogRecPtr, KeepLogSeg(), LocalSetXLogInsertAllowed(), LocalXLogInsertAllowed, log_checkpoints, LogCheckpointEnd(), LogCheckpointStart(), LogStandbySnapshot(), LW_EXCLUSIVE, LW_SHARED, LWLockAcquire(), LWLockRelease(), MemSet, ControlFileData::minRecoveryPoint, ControlFileData::minRecoveryPointTLI, MultiXactGetCheckptMulti(), NBuffers, TransamVariablesData::newestCommitTsXid, CheckPoint::newestCommitTsXid, CheckPoint::nextMulti, CheckPoint::nextMultiOffset, TransamVariablesData::nextOid, CheckPoint::nextOid, TransamVariablesData::nextXid, CheckPoint::nextXid, TransamVariablesData::oidCount, CheckPoint::oldestActiveXid, TransamVariablesData::oldestCommitTsXid, CheckPoint::oldestCommitTsXid, CheckPoint::oldestMulti, CheckPoint::oldestMultiDB, TransamVariablesData::oldestXid, CheckPoint::oldestXid, TransamVariablesData::oldestXidDB, CheckPoint::oldestXidDB, PANIC, pfree(), pg_atomic_read_membarrier_u64(), pg_usleep(), pgstat_report_wait_end(), pgstat_report_wait_start(), PreallocXlogFiles(), XLogCtlData::PrevTimeLineID, CheckPoint::PrevTimeLineID, ProcLastRecPtr, RecoveryInProgress(), CheckPoint::redo, RedoRecPtr, XLogCtlInsert::RedoRecPtr, XLogCtlData::RedoRecPtr, RemoveOldXlogFiles(), RS_INVAL_WAL_REMOVED, SizeOfXLogLongPHD, SizeOfXLogShortPHD, SpinLockAcquire, SpinLockRelease, START_CRIT_SECTION, ControlFileData::state, SyncPostCheckpoint(), SyncPreCheckpoint(), CheckPoint::ThisTimeLineID, CheckPoint::time, TransamVariables, TruncateSUBTRANS(), XLogCtlData::unloggedLSN, ControlFileData::unloggedLSN, update_checkpoint_display(), UpdateCheckPointDistanceEstimate(), UpdateControlFile(), WakeupWalSummarizer(), wal_level, CheckPoint::wal_level, wal_segment_size, WALInsertLockAcquireExclusive(), WALInsertLockRelease(), XLByteToSeg, XLOG_CHECKPOINT_ONLINE, XLOG_CHECKPOINT_REDO, XLOG_CHECKPOINT_SHUTDOWN, XLogBeginInsert(), XLogBytePosToRecPtr(), XLogCtl, XLogFlush(), XLogInsert(), XLogRegisterData(), XLogSegmentOffset, and XLogStandbyInfoActive.

Referenced by CheckpointerMain(), RequestCheckpoint(), and ShutdownXLOG().

◆ CreateEndOfRecoveryRecord()

static void CreateEndOfRecoveryRecord ( void  )
static

Definition at line 7375 of file xlog.c.

7376{
7377 xl_end_of_recovery xlrec;
7378 XLogRecPtr recptr;
7379
7380 /* sanity check */
7381 if (!RecoveryInProgress())
7382 elog(ERROR, "can only be used to end recovery");
7383
7384 xlrec.end_time = GetCurrentTimestamp();
7385 xlrec.wal_level = wal_level;
7386
7391
7393
7395 XLogRegisterData((char *) &xlrec, sizeof(xl_end_of_recovery));
7396 recptr = XLogInsert(RM_XLOG_ID, XLOG_END_OF_RECOVERY);
7397
7398 XLogFlush(recptr);
7399
7400 /*
7401 * Update the control file so that crash recovery can follow the timeline
7402 * changes to this point.
7403 */
7404 LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
7405 ControlFile->minRecoveryPoint = recptr;
7406 ControlFile->minRecoveryPointTLI = xlrec.ThisTimeLineID;
7408 LWLockRelease(ControlFileLock);
7409
7411}
#define XLOG_END_OF_RECOVERY
Definition: pg_control.h:77
TimeLineID PrevTimeLineID
TimestampTz end_time
TimeLineID ThisTimeLineID

References ControlFile, elog, END_CRIT_SECTION, xl_end_of_recovery::end_time, ERROR, GetCurrentTimestamp(), XLogCtlData::InsertTimeLineID, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), ControlFileData::minRecoveryPoint, ControlFileData::minRecoveryPointTLI, XLogCtlData::PrevTimeLineID, xl_end_of_recovery::PrevTimeLineID, RecoveryInProgress(), START_CRIT_SECTION, xl_end_of_recovery::ThisTimeLineID, UpdateControlFile(), wal_level, xl_end_of_recovery::wal_level, WALInsertLockAcquireExclusive(), WALInsertLockRelease(), XLOG_END_OF_RECOVERY, XLogBeginInsert(), XLogCtl, XLogFlush(), XLogInsert(), and XLogRegisterData().

Referenced by PerformRecoveryXLogAction().

◆ CreateOverwriteContrecordRecord()

static XLogRecPtr CreateOverwriteContrecordRecord ( XLogRecPtr  aborted_lsn,
XLogRecPtr  pagePtr,
TimeLineID  newTLI 
)
static

Definition at line 7440 of file xlog.c.

7442{
7444 XLogRecPtr recptr;
7445 XLogPageHeader pagehdr;
7446 XLogRecPtr startPos;
7447
7448 /* sanity checks */
7449 if (!RecoveryInProgress())
7450 elog(ERROR, "can only be used at end of recovery");
7451 if (pagePtr % XLOG_BLCKSZ != 0)
7452 elog(ERROR, "invalid position for missing continuation record %X/%X",
7453 LSN_FORMAT_ARGS(pagePtr));
7454
7455 /* The current WAL insert position should be right after the page header */
7456 startPos = pagePtr;
7457 if (XLogSegmentOffset(startPos, wal_segment_size) == 0)
7458 startPos += SizeOfXLogLongPHD;
7459 else
7460 startPos += SizeOfXLogShortPHD;
7461 recptr = GetXLogInsertRecPtr();
7462 if (recptr != startPos)
7463 elog(ERROR, "invalid WAL insert position %X/%X for OVERWRITE_CONTRECORD",
7464 LSN_FORMAT_ARGS(recptr));
7465
7467
7468 /*
7469 * Initialize the XLOG page header (by GetXLogBuffer), and set the
7470 * XLP_FIRST_IS_OVERWRITE_CONTRECORD flag.
7471 *
7472 * No other backend is allowed to write WAL yet, so acquiring the WAL
7473 * insertion lock is just pro forma.
7474 */
7476 pagehdr = (XLogPageHeader) GetXLogBuffer(pagePtr, newTLI);
7479
7480 /*
7481 * Insert the XLOG_OVERWRITE_CONTRECORD record as the first record on the
7482 * page. We know it becomes the first record, because no other backend is
7483 * allowed to write WAL yet.
7484 */
7486 xlrec.overwritten_lsn = aborted_lsn;
7488 XLogRegisterData((char *) &xlrec, sizeof(xl_overwrite_contrecord));
7489 recptr = XLogInsert(RM_XLOG_ID, XLOG_OVERWRITE_CONTRECORD);
7490
7491 /* check that the record was inserted to the right place */
7492 if (ProcLastRecPtr != startPos)
7493 elog(ERROR, "OVERWRITE_CONTRECORD was inserted to unexpected position %X/%X",
7495
7496 XLogFlush(recptr);
7497
7499
7500 return recptr;
7501}
#define XLOG_OVERWRITE_CONTRECORD
Definition: pg_control.h:81
static void WALInsertLockAcquire(void)
Definition: xlog.c:1371
XLogRecPtr GetXLogInsertRecPtr(void)
Definition: xlog.c:9435
#define XLP_FIRST_IS_OVERWRITE_CONTRECORD
Definition: xlog_internal.h:80

References elog, END_CRIT_SECTION, ERROR, GetCurrentTimestamp(), GetXLogBuffer(), GetXLogInsertRecPtr(), LSN_FORMAT_ARGS, xl_overwrite_contrecord::overwrite_time, xl_overwrite_contrecord::overwritten_lsn, ProcLastRecPtr, RecoveryInProgress(), SizeOfXLogLongPHD, SizeOfXLogShortPHD, START_CRIT_SECTION, wal_segment_size, WALInsertLockAcquire(), WALInsertLockRelease(), XLOG_OVERWRITE_CONTRECORD, XLogBeginInsert(), XLogFlush(), XLogInsert(), XLogRegisterData(), XLogSegmentOffset, XLP_FIRST_IS_OVERWRITE_CONTRECORD, and XLogPageHeaderData::xlp_info.

Referenced by StartupXLOG().

◆ CreateRestartPoint()

bool CreateRestartPoint ( int  flags)

Definition at line 7591 of file xlog.c.

7592{
7593 XLogRecPtr lastCheckPointRecPtr;
7594 XLogRecPtr lastCheckPointEndPtr;
7595 CheckPoint lastCheckPoint;
7596 XLogRecPtr PriorRedoPtr;
7597 XLogRecPtr receivePtr;
7598 XLogRecPtr replayPtr;
7599 TimeLineID replayTLI;
7600 XLogRecPtr endptr;
7601 XLogSegNo _logSegNo;
7602 TimestampTz xtime;
7603
7604 /* Concurrent checkpoint/restartpoint cannot happen */
7606
7607 /* Get a local copy of the last safe checkpoint record. */
7609 lastCheckPointRecPtr = XLogCtl->lastCheckPointRecPtr;
7610 lastCheckPointEndPtr = XLogCtl->lastCheckPointEndPtr;
7611 lastCheckPoint = XLogCtl->lastCheckPoint;
7613
7614 /*
7615 * Check that we're still in recovery mode. It's ok if we exit recovery
7616 * mode after this check, the restart point is valid anyway.
7617 */
7618 if (!RecoveryInProgress())
7619 {
7621 (errmsg_internal("skipping restartpoint, recovery has already ended")));
7622 return false;
7623 }
7624
7625 /*
7626 * If the last checkpoint record we've replayed is already our last
7627 * restartpoint, we can't perform a new restart point. We still update
7628 * minRecoveryPoint in that case, so that if this is a shutdown restart
7629 * point, we won't start up earlier than before. That's not strictly
7630 * necessary, but when hot standby is enabled, it would be rather weird if
7631 * the database opened up for read-only connections at a point-in-time
7632 * before the last shutdown. Such time travel is still possible in case of
7633 * immediate shutdown, though.
7634 *
7635 * We don't explicitly advance minRecoveryPoint when we do create a
7636 * restartpoint. It's assumed that flushing the buffers will do that as a
7637 * side-effect.
7638 */
7639 if (XLogRecPtrIsInvalid(lastCheckPointRecPtr) ||
7640 lastCheckPoint.redo <= ControlFile->checkPointCopy.redo)
7641 {
7643 (errmsg_internal("skipping restartpoint, already performed at %X/%X",
7644 LSN_FORMAT_ARGS(lastCheckPoint.redo))));
7645
7647 if (flags & CHECKPOINT_IS_SHUTDOWN)
7648 {
7649 LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
7652 LWLockRelease(ControlFileLock);
7653 }
7654 return false;
7655 }
7656
7657 /*
7658 * Update the shared RedoRecPtr so that the startup process can calculate
7659 * the number of segments replayed since last restartpoint, and request a
7660 * restartpoint if it exceeds CheckPointSegments.
7661 *
7662 * Like in CreateCheckPoint(), hold off insertions to update it, although
7663 * during recovery this is just pro forma, because no WAL insertions are
7664 * happening.
7665 */
7667 RedoRecPtr = XLogCtl->Insert.RedoRecPtr = lastCheckPoint.redo;
7669
7670 /* Also update the info_lck-protected copy */
7672 XLogCtl->RedoRecPtr = lastCheckPoint.redo;
7674
7675 /*
7676 * Prepare to accumulate statistics.
7677 *
7678 * Note: because it is possible for log_checkpoints to change while a
7679 * checkpoint proceeds, we always accumulate stats, even if
7680 * log_checkpoints is currently off.
7681 */
7684
7685 if (log_checkpoints)
7686 LogCheckpointStart(flags, true);
7687
7688 /* Update the process title */
7689 update_checkpoint_display(flags, true, false);
7690
7691 CheckPointGuts(lastCheckPoint.redo, flags);
7692
7693 /*
7694 * This location needs to be after CheckPointGuts() to ensure that some
7695 * work has already happened during this checkpoint.
7696 */
7697 INJECTION_POINT("create-restart-point");
7698
7699 /*
7700 * Remember the prior checkpoint's redo ptr for
7701 * UpdateCheckPointDistanceEstimate()
7702 */
7703 PriorRedoPtr = ControlFile->checkPointCopy.redo;
7704
7705 /*
7706 * Update pg_control, using current time. Check that it still shows an
7707 * older checkpoint, else do nothing; this is a quick hack to make sure
7708 * nothing really bad happens if somehow we get here after the
7709 * end-of-recovery checkpoint.
7710 */
7711 LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
7712 if (ControlFile->checkPointCopy.redo < lastCheckPoint.redo)
7713 {
7714 /*
7715 * Update the checkpoint information. We do this even if the cluster
7716 * does not show DB_IN_ARCHIVE_RECOVERY to match with the set of WAL
7717 * segments recycled below.
7718 */
7719 ControlFile->checkPoint = lastCheckPointRecPtr;
7720 ControlFile->checkPointCopy = lastCheckPoint;
7721
7722 /*
7723 * Ensure minRecoveryPoint is past the checkpoint record and update it
7724 * if the control file still shows DB_IN_ARCHIVE_RECOVERY. Normally,
7725 * this will have happened already while writing out dirty buffers,
7726 * but not necessarily - e.g. because no buffers were dirtied. We do
7727 * this because a backup performed in recovery uses minRecoveryPoint
7728 * to determine which WAL files must be included in the backup, and
7729 * the file (or files) containing the checkpoint record must be
7730 * included, at a minimum. Note that for an ordinary restart of
7731 * recovery there's no value in having the minimum recovery point any
7732 * earlier than this anyway, because redo will begin just after the
7733 * checkpoint record.
7734 */
7736 {
7737 if (ControlFile->minRecoveryPoint < lastCheckPointEndPtr)
7738 {
7739 ControlFile->minRecoveryPoint = lastCheckPointEndPtr;
7741
7742 /* update local copy */
7745 }
7746 if (flags & CHECKPOINT_IS_SHUTDOWN)
7748 }
7750 }
7751 LWLockRelease(ControlFileLock);
7752
7753 /*
7754 * Update the average distance between checkpoints/restartpoints if the
7755 * prior checkpoint exists.
7756 */
7757 if (PriorRedoPtr != InvalidXLogRecPtr)
7759
7760 /*
7761 * Delete old log files, those no longer needed for last restartpoint to
7762 * prevent the disk holding the xlog from growing full.
7763 */
7765
7766 /*
7767 * Retreat _logSegNo using the current end of xlog replayed or received,
7768 * whichever is later.
7769 */
7770 receivePtr = GetWalRcvFlushRecPtr(NULL, NULL);
7771 replayPtr = GetXLogReplayRecPtr(&replayTLI);
7772 endptr = (receivePtr < replayPtr) ? replayPtr : receivePtr;
7773 KeepLogSeg(endptr, &_logSegNo);
7775 _logSegNo, InvalidOid,
7777 {
7778 /*
7779 * Some slots have been invalidated; recalculate the old-segment
7780 * horizon, starting again from RedoRecPtr.
7781 */
7783 KeepLogSeg(endptr, &_logSegNo);
7784 }
7785 _logSegNo--;
7786
7787 /*
7788 * Try to recycle segments on a useful timeline. If we've been promoted
7789 * since the beginning of this restartpoint, use the new timeline chosen
7790 * at end of recovery. If we're still in recovery, use the timeline we're
7791 * currently replaying.
7792 *
7793 * There is no guarantee that the WAL segments will be useful on the
7794 * current timeline; if recovery proceeds to a new timeline right after
7795 * this, the pre-allocated WAL segments on this timeline will not be used,
7796 * and will go wasted until recycled on the next restartpoint. We'll live
7797 * with that.
7798 */
7799 if (!RecoveryInProgress())
7800 replayTLI = XLogCtl->InsertTimeLineID;
7801
7802 RemoveOldXlogFiles(_logSegNo, RedoRecPtr, endptr, replayTLI);
7803
7804 /*
7805 * Make more log segments if needed. (Do this after recycling old log
7806 * segments, since that may supply some of the needed files.)
7807 */
7808 PreallocXlogFiles(endptr, replayTLI);
7809
7810 /*
7811 * Truncate pg_subtrans if possible. We can throw away all data before
7812 * the oldest XMIN of any running transaction. No future transaction will
7813 * attempt to reference any pg_subtrans entry older than that (see Asserts
7814 * in subtrans.c). When hot standby is disabled, though, we mustn't do
7815 * this because StartupSUBTRANS hasn't been called yet.
7816 */
7817 if (EnableHotStandby)
7819
7820 /* Real work is done; log and update stats. */
7821 LogCheckpointEnd(true);
7822
7823 /* Reset the process title */
7824 update_checkpoint_display(flags, true, true);
7825
7826 xtime = GetLatestXTime();
7828 (errmsg("recovery restart point at %X/%X",
7829 LSN_FORMAT_ARGS(lastCheckPoint.redo)),
7830 xtime ? errdetail("Last completed transaction was at log time %s.",
7831 timestamptz_to_str(xtime)) : 0));
7832
7833 /*
7834 * Finally, execute archive_cleanup_command, if any.
7835 */
7836 if (archiveCleanupCommand && strcmp(archiveCleanupCommand, "") != 0)
7838 "archive_cleanup_command",
7839 false,
7840 WAIT_EVENT_ARCHIVE_CLEANUP_COMMAND);
7841
7842 return true;
7843}
const char * timestamptz_to_str(TimestampTz t)
Definition: timestamp.c:1843
int64 TimestampTz
Definition: timestamp.h:39
#define LOG
Definition: elog.h:31
bool IsUnderPostmaster
Definition: globals.c:119
#define INJECTION_POINT(name)
@ B_CHECKPOINTER
Definition: miscadmin.h:362
BackendType MyBackendType
Definition: miscinit.c:64
@ DB_IN_ARCHIVE_RECOVERY
Definition: pg_control.h:96
@ DB_SHUTDOWNED_IN_RECOVERY
Definition: pg_control.h:93
CheckPoint lastCheckPoint
Definition: xlog.c:545
XLogRecPtr lastCheckPointRecPtr
Definition: xlog.c:543
XLogRecPtr lastCheckPointEndPtr
Definition: xlog.c:544
XLogRecPtr GetWalRcvFlushRecPtr(XLogRecPtr *latestChunkStart, TimeLineID *receiveTLI)
static void UpdateMinRecoveryPoint(XLogRecPtr lsn, bool force)
Definition: xlog.c:2722
static XLogRecPtr LocalMinRecoveryPoint
Definition: xlog.c:646
static TimeLineID LocalMinRecoveryPointTLI
Definition: xlog.c:647
#define XLogRecPtrIsInvalid(r)
Definition: xlogdefs.h:29
uint32 TimeLineID
Definition: xlogdefs.h:59
char * archiveCleanupCommand
Definition: xlogrecovery.c:84
XLogRecPtr GetXLogReplayRecPtr(TimeLineID *replayTLI)
TimestampTz GetLatestXTime(void)

References archiveCleanupCommand, Assert, B_CHECKPOINTER, ControlFileData::checkPoint, CHECKPOINT_IS_SHUTDOWN, ControlFileData::checkPointCopy, CheckPointGuts(), CheckpointStats, CheckpointStatsData::ckpt_start_t, ControlFile, DB_IN_ARCHIVE_RECOVERY, DB_SHUTDOWNED_IN_RECOVERY, DEBUG2, EnableHotStandby, ereport, errdetail(), errmsg(), errmsg_internal(), ExecuteRecoveryCommand(), GetCurrentTimestamp(), GetLatestXTime(), GetOldestTransactionIdConsideredRunning(), GetWalRcvFlushRecPtr(), GetXLogReplayRecPtr(), XLogCtlData::info_lck, INJECTION_POINT, XLogCtlData::Insert, XLogCtlData::InsertTimeLineID, InvalidateObsoleteReplicationSlots(), InvalidOid, InvalidTransactionId, InvalidXLogRecPtr, IsUnderPostmaster, KeepLogSeg(), XLogCtlData::lastCheckPoint, XLogCtlData::lastCheckPointEndPtr, XLogCtlData::lastCheckPointRecPtr, LocalMinRecoveryPoint, LocalMinRecoveryPointTLI, LOG, log_checkpoints, LogCheckpointEnd(), LogCheckpointStart(), LSN_FORMAT_ARGS, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), MemSet, ControlFileData::minRecoveryPoint, ControlFileData::minRecoveryPointTLI, MyBackendType, PreallocXlogFiles(), RecoveryInProgress(), CheckPoint::redo, RedoRecPtr, XLogCtlInsert::RedoRecPtr, XLogCtlData::RedoRecPtr, RemoveOldXlogFiles(), RS_INVAL_WAL_REMOVED, SpinLockAcquire, SpinLockRelease, ControlFileData::state, CheckPoint::ThisTimeLineID, timestamptz_to_str(), TruncateSUBTRANS(), update_checkpoint_display(), UpdateCheckPointDistanceEstimate(), UpdateControlFile(), UpdateMinRecoveryPoint(), wal_segment_size, WALInsertLockAcquireExclusive(), WALInsertLockRelease(), XLByteToSeg, XLogCtl, and XLogRecPtrIsInvalid.

Referenced by CheckpointerMain(), and ShutdownXLOG().

◆ DataChecksumsEnabled()

◆ do_pg_abort_backup()

void do_pg_abort_backup ( int  code,
Datum  arg 
)

Definition at line 9394 of file xlog.c.

9395{
9396 bool during_backup_start = DatumGetBool(arg);
9397
9398 /* If called during backup start, there shouldn't be one already running */
9399 Assert(!during_backup_start || sessionBackupState == SESSION_BACKUP_NONE);
9400
9401 if (during_backup_start || sessionBackupState != SESSION_BACKUP_NONE)
9402 {
9406
9409
9410 if (!during_backup_start)
9412 errmsg("aborting backup due to backend exiting before pg_backup_stop was called"));
9413 }
9414}
#define WARNING
Definition: elog.h:36
void * arg
static bool DatumGetBool(Datum X)
Definition: postgres.h:90
int runningBackups
Definition: xlog.c:438
static SessionBackupState sessionBackupState
Definition: xlog.c:391
@ SESSION_BACKUP_NONE
Definition: xlog.h:287

References arg, Assert, DatumGetBool(), ereport, errmsg(), XLogCtlData::Insert, XLogCtlInsert::runningBackups, SESSION_BACKUP_NONE, sessionBackupState, WALInsertLockAcquireExclusive(), WALInsertLockRelease(), WARNING, and XLogCtl.

Referenced by do_pg_backup_start(), perform_base_backup(), and register_persistent_abort_backup_handler().

◆ do_pg_backup_start()

void do_pg_backup_start ( const char *  backupidstr,
bool  fast,
List **  tablespaces,
BackupState state,
StringInfo  tblspcmapfile 
)

Definition at line 8792 of file xlog.c.

8794{
8796
8797 Assert(state != NULL);
8799
8800 /*
8801 * During recovery, we don't need to check WAL level. Because, if WAL
8802 * level is not sufficient, it's impossible to get here during recovery.
8803 */
8805 ereport(ERROR,
8806 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
8807 errmsg("WAL level not sufficient for making an online backup"),
8808 errhint("\"wal_level\" must be set to \"replica\" or \"logical\" at server start.")));
8809
8810 if (strlen(backupidstr) > MAXPGPATH)
8811 ereport(ERROR,
8812 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
8813 errmsg("backup label too long (max %d bytes)",
8814 MAXPGPATH)));
8815
8816 strlcpy(state->name, backupidstr, sizeof(state->name));
8817
8818 /*
8819 * Mark backup active in shared memory. We must do full-page WAL writes
8820 * during an on-line backup even if not doing so at other times, because
8821 * it's quite possible for the backup dump to obtain a "torn" (partially
8822 * written) copy of a database page if it reads the page concurrently with
8823 * our write to the same page. This can be fixed as long as the first
8824 * write to the page in the WAL sequence is a full-page write. Hence, we
8825 * increment runningBackups then force a CHECKPOINT, to ensure there are
8826 * no dirty pages in shared memory that might get dumped while the backup
8827 * is in progress without having a corresponding WAL record. (Once the
8828 * backup is complete, we need not force full-page writes anymore, since
8829 * we expect that any pages not modified during the backup interval must
8830 * have been correctly captured by the backup.)
8831 *
8832 * Note that forcing full-page writes has no effect during an online
8833 * backup from the standby.
8834 *
8835 * We must hold all the insertion locks to change the value of
8836 * runningBackups, to ensure adequate interlocking against
8837 * XLogInsertRecord().
8838 */
8842
8843 /*
8844 * Ensure we decrement runningBackups if we fail below. NB -- for this to
8845 * work correctly, it is critical that sessionBackupState is only updated
8846 * after this block is over.
8847 */
8849 {
8850 bool gotUniqueStartpoint = false;
8851 DIR *tblspcdir;
8852 struct dirent *de;
8853 tablespaceinfo *ti;
8854 int datadirpathlen;
8855
8856 /*
8857 * Force an XLOG file switch before the checkpoint, to ensure that the
8858 * WAL segment the checkpoint is written to doesn't contain pages with
8859 * old timeline IDs. That would otherwise happen if you called
8860 * pg_backup_start() right after restoring from a PITR archive: the
8861 * first WAL segment containing the startup checkpoint has pages in
8862 * the beginning with the old timeline ID. That can cause trouble at
8863 * recovery: we won't have a history file covering the old timeline if
8864 * pg_wal directory was not included in the base backup and the WAL
8865 * archive was cleared too before starting the backup.
8866 *
8867 * This also ensures that we have emitted a WAL page header that has
8868 * XLP_BKP_REMOVABLE off before we emit the checkpoint record.
8869 * Therefore, if a WAL archiver (such as pglesslog) is trying to
8870 * compress out removable backup blocks, it won't remove any that
8871 * occur after this point.
8872 *
8873 * During recovery, we skip forcing XLOG file switch, which means that
8874 * the backup taken during recovery is not available for the special
8875 * recovery case described above.
8876 */
8878 RequestXLogSwitch(false);
8879
8880 do
8881 {
8882 bool checkpointfpw;
8883
8884 /*
8885 * Force a CHECKPOINT. Aside from being necessary to prevent torn
8886 * page problems, this guarantees that two successive backup runs
8887 * will have different checkpoint positions and hence different
8888 * history file names, even if nothing happened in between.
8889 *
8890 * During recovery, establish a restartpoint if possible. We use
8891 * the last restartpoint as the backup starting checkpoint. This
8892 * means that two successive backup runs can have same checkpoint
8893 * positions.
8894 *
8895 * Since the fact that we are executing do_pg_backup_start()
8896 * during recovery means that checkpointer is running, we can use
8897 * RequestCheckpoint() to establish a restartpoint.
8898 *
8899 * We use CHECKPOINT_IMMEDIATE only if requested by user (via
8900 * passing fast = true). Otherwise this can take awhile.
8901 */
8903 (fast ? CHECKPOINT_IMMEDIATE : 0));
8904
8905 /*
8906 * Now we need to fetch the checkpoint record location, and also
8907 * its REDO pointer. The oldest point in WAL that would be needed
8908 * to restore starting from the checkpoint is precisely the REDO
8909 * pointer.
8910 */
8911 LWLockAcquire(ControlFileLock, LW_SHARED);
8912 state->checkpointloc = ControlFile->checkPoint;
8913 state->startpoint = ControlFile->checkPointCopy.redo;
8915 checkpointfpw = ControlFile->checkPointCopy.fullPageWrites;
8916 LWLockRelease(ControlFileLock);
8917
8919 {
8920 XLogRecPtr recptr;
8921
8922 /*
8923 * Check to see if all WAL replayed during online backup
8924 * (i.e., since last restartpoint used as backup starting
8925 * checkpoint) contain full-page writes.
8926 */
8928 recptr = XLogCtl->lastFpwDisableRecPtr;
8930
8931 if (!checkpointfpw || state->startpoint <= recptr)
8932 ereport(ERROR,
8933 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
8934 errmsg("WAL generated with \"full_page_writes=off\" was replayed "
8935 "since last restartpoint"),
8936 errhint("This means that the backup being taken on the standby "
8937 "is corrupt and should not be used. "
8938 "Enable \"full_page_writes\" and run CHECKPOINT on the primary, "
8939 "and then try an online backup again.")));
8940
8941 /*
8942 * During recovery, since we don't use the end-of-backup WAL
8943 * record and don't write the backup history file, the
8944 * starting WAL location doesn't need to be unique. This means
8945 * that two base backups started at the same time might use
8946 * the same checkpoint as starting locations.
8947 */
8948 gotUniqueStartpoint = true;
8949 }
8950
8951 /*
8952 * If two base backups are started at the same time (in WAL sender
8953 * processes), we need to make sure that they use different
8954 * checkpoints as starting locations, because we use the starting
8955 * WAL location as a unique identifier for the base backup in the
8956 * end-of-backup WAL record and when we write the backup history
8957 * file. Perhaps it would be better generate a separate unique ID
8958 * for each backup instead of forcing another checkpoint, but
8959 * taking a checkpoint right after another is not that expensive
8960 * either because only few buffers have been dirtied yet.
8961 */
8963 if (XLogCtl->Insert.lastBackupStart < state->startpoint)
8964 {
8965 XLogCtl->Insert.lastBackupStart = state->startpoint;
8966 gotUniqueStartpoint = true;
8967 }
8969 } while (!gotUniqueStartpoint);
8970
8971 /*
8972 * Construct tablespace_map file.
8973 */
8974 datadirpathlen = strlen(DataDir);
8975
8976 /* Collect information about all tablespaces */
8977 tblspcdir = AllocateDir(PG_TBLSPC_DIR);
8978 while ((de = ReadDir(tblspcdir, PG_TBLSPC_DIR)) != NULL)
8979 {
8980 char fullpath[MAXPGPATH + sizeof(PG_TBLSPC_DIR)];
8981 char linkpath[MAXPGPATH];
8982 char *relpath = NULL;
8983 char *s;
8984 PGFileType de_type;
8985 char *badp;
8986 Oid tsoid;
8987
8988 /*
8989 * Try to parse the directory name as an unsigned integer.
8990 *
8991 * Tablespace directories should be positive integers that can be
8992 * represented in 32 bits, with no leading zeroes or trailing
8993 * garbage. If we come across a name that doesn't meet those
8994 * criteria, skip it.
8995 */
8996 if (de->d_name[0] < '1' || de->d_name[1] > '9')
8997 continue;
8998 errno = 0;
8999 tsoid = strtoul(de->d_name, &badp, 10);
9000 if (*badp != '\0' || errno == EINVAL || errno == ERANGE)
9001 continue;
9002
9003 snprintf(fullpath, sizeof(fullpath), "%s/%s", PG_TBLSPC_DIR, de->d_name);
9004
9005 de_type = get_dirent_type(fullpath, de, false, ERROR);
9006
9007 if (de_type == PGFILETYPE_LNK)
9008 {
9009 StringInfoData escapedpath;
9010 int rllen;
9011
9012 rllen = readlink(fullpath, linkpath, sizeof(linkpath));
9013 if (rllen < 0)
9014 {
9016 (errmsg("could not read symbolic link \"%s\": %m",
9017 fullpath)));
9018 continue;
9019 }
9020 else if (rllen >= sizeof(linkpath))
9021 {
9023 (errmsg("symbolic link \"%s\" target is too long",
9024 fullpath)));
9025 continue;
9026 }
9027 linkpath[rllen] = '\0';
9028
9029 /*
9030 * Relpath holds the relative path of the tablespace directory
9031 * when it's located within PGDATA, or NULL if it's located
9032 * elsewhere.
9033 */
9034 if (rllen > datadirpathlen &&
9035 strncmp(linkpath, DataDir, datadirpathlen) == 0 &&
9036 IS_DIR_SEP(linkpath[datadirpathlen]))
9037 relpath = pstrdup(linkpath + datadirpathlen + 1);
9038
9039 /*
9040 * Add a backslash-escaped version of the link path to the
9041 * tablespace map file.
9042 */
9043 initStringInfo(&escapedpath);
9044 for (s = linkpath; *s; s++)
9045 {
9046 if (*s == '\n' || *s == '\r' || *s == '\\')
9047 appendStringInfoChar(&escapedpath, '\\');
9048 appendStringInfoChar(&escapedpath, *s);
9049 }
9050 appendStringInfo(tblspcmapfile, "%s %s\n",
9051 de->d_name, escapedpath.data);
9052 pfree(escapedpath.data);
9053 }
9054 else if (de_type == PGFILETYPE_DIR)
9055 {
9056 /*
9057 * It's possible to use allow_in_place_tablespaces to create
9058 * directories directly under pg_tblspc, for testing purposes
9059 * only.
9060 *
9061 * In this case, we store a relative path rather than an
9062 * absolute path into the tablespaceinfo.
9063 */
9064 snprintf(linkpath, sizeof(linkpath), "%s/%s",
9065 PG_TBLSPC_DIR, de->d_name);
9066 relpath = pstrdup(linkpath);
9067 }
9068 else
9069 {
9070 /* Skip any other file type that appears here. */
9071 continue;
9072 }
9073
9074 ti = palloc(sizeof(tablespaceinfo));
9075 ti->oid = tsoid;
9076 ti->path = pstrdup(linkpath);
9077 ti->rpath = relpath;
9078 ti->size = -1;
9079
9080 if (tablespaces)
9081 *tablespaces = lappend(*tablespaces, ti);
9082 }
9083 FreeDir(tblspcdir);
9084
9085 state->starttime = (pg_time_t) time(NULL);
9086 }
9088
9089 state->started_in_recovery = backup_started_in_recovery;
9090
9091 /*
9092 * Mark that the start phase has correctly finished for the backup.
9093 */
9095}
static bool backup_started_in_recovery
Definition: basebackup.c:123
void RequestCheckpoint(int flags)
Definition: checkpointer.c:952
PGFileType get_dirent_type(const char *path, const struct dirent *de, bool look_through_symlinks, int elevel)
Definition: file_utils.c:526
PGFileType
Definition: file_utils.h:19
@ PGFILETYPE_LNK
Definition: file_utils.h:24
@ PGFILETYPE_DIR
Definition: file_utils.h:23
char * DataDir
Definition: globals.c:70
#define PG_ENSURE_ERROR_CLEANUP(cleanup_function, arg)
Definition: ipc.h:47
#define PG_END_ENSURE_ERROR_CLEANUP(cleanup_function, arg)
Definition: ipc.h:52
List * lappend(List *list, void *datum)
Definition: list.c:339
#define IS_DIR_SEP(ch)
Definition: port.h:102
size_t strlcpy(char *dst, const char *src, size_t siz)
Definition: strlcpy.c:45
unsigned int Oid
Definition: postgres_ext.h:31
#define relpath(rlocator, forknum)
Definition: relpath.h:102
#define PG_TBLSPC_DIR
Definition: relpath.h:41
void appendStringInfo(StringInfo str, const char *fmt,...)
Definition: stringinfo.c:94
void appendStringInfoChar(StringInfo str, char ch)
Definition: stringinfo.c:191
void initStringInfo(StringInfo str)
Definition: stringinfo.c:56
XLogRecPtr lastFpwDisableRecPtr
Definition: xlog.c:551
XLogRecPtr lastBackupStart
Definition: xlog.c:439
Definition: regguts.h:323
char * rpath
Definition: basebackup.h:32
#define readlink(path, buf, size)
Definition: win32_port.h:236
XLogRecPtr RequestXLogSwitch(bool mark_unimportant)
Definition: xlog.c:8060
void do_pg_abort_backup(int code, Datum arg)
Definition: xlog.c:9394
@ SESSION_BACKUP_RUNNING
Definition: xlog.h:288
#define CHECKPOINT_WAIT
Definition: xlog.h:145
#define CHECKPOINT_IMMEDIATE
Definition: xlog.h:141
#define XLogIsNeeded()
Definition: xlog.h:109

References AllocateDir(), appendStringInfo(), appendStringInfoChar(), Assert, backup_started_in_recovery, ControlFileData::checkPoint, CHECKPOINT_FORCE, CHECKPOINT_IMMEDIATE, CHECKPOINT_WAIT, ControlFileData::checkPointCopy, ControlFile, dirent::d_name, StringInfoData::data, DataDir, DatumGetBool(), do_pg_abort_backup(), ereport, errcode(), errhint(), errmsg(), ERROR, FreeDir(), CheckPoint::fullPageWrites, get_dirent_type(), XLogCtlData::info_lck, initStringInfo(), XLogCtlData::Insert, IS_DIR_SEP, lappend(), XLogCtlInsert::lastBackupStart, XLogCtlData::lastFpwDisableRecPtr, LW_SHARED, LWLockAcquire(), LWLockRelease(), MAXPGPATH, tablespaceinfo::oid, palloc(), tablespaceinfo::path, pfree(), PG_END_ENSURE_ERROR_CLEANUP, PG_ENSURE_ERROR_CLEANUP, PG_TBLSPC_DIR, PGFILETYPE_DIR, PGFILETYPE_LNK, pstrdup(), ReadDir(), readlink, RecoveryInProgress(), CheckPoint::redo, relpath, RequestCheckpoint(), RequestXLogSwitch(), tablespaceinfo::rpath, XLogCtlInsert::runningBackups, SESSION_BACKUP_RUNNING, sessionBackupState, tablespaceinfo::size, snprintf, SpinLockAcquire, SpinLockRelease, strlcpy(), CheckPoint::ThisTimeLineID, WALInsertLockAcquireExclusive(), WALInsertLockRelease(), WARNING, XLogCtl, and XLogIsNeeded.

Referenced by perform_base_backup(), and pg_backup_start().

◆ do_pg_backup_stop()

void do_pg_backup_stop ( BackupState state,
bool  waitforarchive 
)

Definition at line 9120 of file xlog.c.

9121{
9122 bool backup_stopped_in_recovery = false;
9123 char histfilepath[MAXPGPATH];
9124 char lastxlogfilename[MAXFNAMELEN];
9125 char histfilename[MAXFNAMELEN];
9126 XLogSegNo _logSegNo;
9127 FILE *fp;
9128 int seconds_before_warning;
9129 int waits = 0;
9130 bool reported_waiting = false;
9131
9132 Assert(state != NULL);
9133
9134 backup_stopped_in_recovery = RecoveryInProgress();
9135
9136 /*
9137 * During recovery, we don't need to check WAL level. Because, if WAL
9138 * level is not sufficient, it's impossible to get here during recovery.
9139 */
9140 if (!backup_stopped_in_recovery && !XLogIsNeeded())
9141 ereport(ERROR,
9142 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
9143 errmsg("WAL level not sufficient for making an online backup"),
9144 errhint("\"wal_level\" must be set to \"replica\" or \"logical\" at server start.")));
9145
9146 /*
9147 * OK to update backup counter and session-level lock.
9148 *
9149 * Note that CHECK_FOR_INTERRUPTS() must not occur while updating them,
9150 * otherwise they can be updated inconsistently, which might cause
9151 * do_pg_abort_backup() to fail.
9152 */
9154
9155 /*
9156 * It is expected that each do_pg_backup_start() call is matched by
9157 * exactly one do_pg_backup_stop() call.
9158 */
9161
9162 /*
9163 * Clean up session-level lock.
9164 *
9165 * You might think that WALInsertLockRelease() can be called before
9166 * cleaning up session-level lock because session-level lock doesn't need
9167 * to be protected with WAL insertion lock. But since
9168 * CHECK_FOR_INTERRUPTS() can occur in it, session-level lock must be
9169 * cleaned up before it.
9170 */
9172
9174
9175 /*
9176 * If we are taking an online backup from the standby, we confirm that the
9177 * standby has not been promoted during the backup.
9178 */
9179 if (state->started_in_recovery && !backup_stopped_in_recovery)
9180 ereport(ERROR,
9181 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
9182 errmsg("the standby was promoted during online backup"),
9183 errhint("This means that the backup being taken is corrupt "
9184 "and should not be used. "
9185 "Try taking another online backup.")));
9186
9187 /*
9188 * During recovery, we don't write an end-of-backup record. We assume that
9189 * pg_control was backed up last and its minimum recovery point can be
9190 * available as the backup end location. Since we don't have an
9191 * end-of-backup record, we use the pg_control value to check whether
9192 * we've reached the end of backup when starting recovery from this
9193 * backup. We have no way of checking if pg_control wasn't backed up last
9194 * however.
9195 *
9196 * We don't force a switch to new WAL file but it is still possible to
9197 * wait for all the required files to be archived if waitforarchive is
9198 * true. This is okay if we use the backup to start a standby and fetch
9199 * the missing WAL using streaming replication. But in the case of an
9200 * archive recovery, a user should set waitforarchive to true and wait for
9201 * them to be archived to ensure that all the required files are
9202 * available.
9203 *
9204 * We return the current minimum recovery point as the backup end
9205 * location. Note that it can be greater than the exact backup end
9206 * location if the minimum recovery point is updated after the backup of
9207 * pg_control. This is harmless for current uses.
9208 *
9209 * XXX currently a backup history file is for informational and debug
9210 * purposes only. It's not essential for an online backup. Furthermore,
9211 * even if it's created, it will not be archived during recovery because
9212 * an archiver is not invoked. So it doesn't seem worthwhile to write a
9213 * backup history file during recovery.
9214 */
9215 if (backup_stopped_in_recovery)
9216 {
9217 XLogRecPtr recptr;
9218
9219 /*
9220 * Check to see if all WAL replayed during online backup contain
9221 * full-page writes.
9222 */
9224 recptr = XLogCtl->lastFpwDisableRecPtr;
9226
9227 if (state->startpoint <= recptr)
9228 ereport(ERROR,
9229 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
9230 errmsg("WAL generated with \"full_page_writes=off\" was replayed "
9231 "during online backup"),
9232 errhint("This means that the backup being taken on the standby "
9233 "is corrupt and should not be used. "
9234 "Enable \"full_page_writes\" and run CHECKPOINT on the primary, "
9235 "and then try an online backup again.")));
9236
9237
9238 LWLockAcquire(ControlFileLock, LW_SHARED);
9239 state->stoppoint = ControlFile->minRecoveryPoint;
9241 LWLockRelease(ControlFileLock);
9242 }
9243 else
9244 {
9245 char *history_file;
9246
9247 /*
9248 * Write the backup-end xlog record
9249 */
9251 XLogRegisterData((char *) (&state->startpoint),
9252 sizeof(state->startpoint));
9253 state->stoppoint = XLogInsert(RM_XLOG_ID, XLOG_BACKUP_END);
9254
9255 /*
9256 * Given that we're not in recovery, InsertTimeLineID is set and can't
9257 * change, so we can read it without a lock.
9258 */
9259 state->stoptli = XLogCtl->InsertTimeLineID;
9260
9261 /*
9262 * Force a switch to a new xlog segment file, so that the backup is
9263 * valid as soon as archiver moves out the current segment file.
9264 */
9265 RequestXLogSwitch(false);
9266
9267 state->stoptime = (pg_time_t) time(NULL);
9268
9269 /*
9270 * Write the backup history file
9271 */
9272 XLByteToSeg(state->startpoint, _logSegNo, wal_segment_size);
9273 BackupHistoryFilePath(histfilepath, state->stoptli, _logSegNo,
9274 state->startpoint, wal_segment_size);
9275 fp = AllocateFile(histfilepath, "w");
9276 if (!fp)
9277 ereport(ERROR,
9279 errmsg("could not create file \"%s\": %m",
9280 histfilepath)));
9281
9282 /* Build and save the contents of the backup history file */
9283 history_file = build_backup_content(state, true);
9284 fprintf(fp, "%s", history_file);
9285 pfree(history_file);
9286
9287 if (fflush(fp) || ferror(fp) || FreeFile(fp))
9288 ereport(ERROR,
9290 errmsg("could not write file \"%s\": %m",
9291 histfilepath)));
9292
9293 /*
9294 * Clean out any no-longer-needed history files. As a side effect,
9295 * this will post a .ready file for the newly created history file,
9296 * notifying the archiver that history file may be archived
9297 * immediately.
9298 */
9300 }
9301
9302 /*
9303 * If archiving is enabled, wait for all the required WAL files to be
9304 * archived before returning. If archiving isn't enabled, the required WAL
9305 * needs to be transported via streaming replication (hopefully with
9306 * wal_keep_size set high enough), or some more exotic mechanism like
9307 * polling and copying files from pg_wal with script. We have no knowledge
9308 * of those mechanisms, so it's up to the user to ensure that he gets all
9309 * the required WAL.
9310 *
9311 * We wait until both the last WAL file filled during backup and the
9312 * history file have been archived, and assume that the alphabetic sorting
9313 * property of the WAL files ensures any earlier WAL files are safely
9314 * archived as well.
9315 *
9316 * We wait forever, since archive_command is supposed to work and we
9317 * assume the admin wanted his backup to work completely. If you don't
9318 * wish to wait, then either waitforarchive should be passed in as false,
9319 * or you can set statement_timeout. Also, some notices are issued to
9320 * clue in anyone who might be doing this interactively.
9321 */
9322
9323 if (waitforarchive &&
9324 ((!backup_stopped_in_recovery && XLogArchivingActive()) ||
9325 (backup_stopped_in_recovery && XLogArchivingAlways())))
9326 {
9327 XLByteToPrevSeg(state->stoppoint, _logSegNo, wal_segment_size);
9328 XLogFileName(lastxlogfilename, state->stoptli, _logSegNo,
9330
9331 XLByteToSeg(state->startpoint, _logSegNo, wal_segment_size);
9332 BackupHistoryFileName(histfilename, state->stoptli, _logSegNo,
9333 state->startpoint, wal_segment_size);
9334
9335 seconds_before_warning = 60;
9336 waits = 0;
9337
9338 while (XLogArchiveIsBusy(lastxlogfilename) ||
9339 XLogArchiveIsBusy(histfilename))
9340 {
9342
9343 if (!reported_waiting && waits > 5)
9344 {
9346 (errmsg("base backup done, waiting for required WAL segments to be archived")));
9347 reported_waiting = true;
9348 }
9349
9350 (void) WaitLatch(MyLatch,
9352 1000L,
9353 WAIT_EVENT_BACKUP_WAIT_WAL_ARCHIVE);
9355
9356 if (++waits >= seconds_before_warning)
9357 {
9358 seconds_before_warning *= 2; /* This wraps in >10 years... */
9360 (errmsg("still waiting for all required WAL segments to be archived (%d seconds elapsed)",
9361 waits),
9362 errhint("Check that your \"archive_command\" is executing properly. "
9363 "You can safely cancel this backup, "
9364 "but the database backup will not be usable without all the WAL segments.")));
9365 }
9366 }
9367
9369 (errmsg("all required WAL segments have been archived")));
9370 }
9371 else if (waitforarchive)
9373 (errmsg("WAL archiving is not enabled; you must ensure that all required WAL segments are copied through other means to complete the backup")));
9374}
#define fprintf(file, fmt, msg)
Definition: cubescan.l:21
#define NOTICE
Definition: elog.h:35
int FreeFile(FILE *file)
Definition: fd.c:2803
FILE * AllocateFile(const char *name, const char *mode)
Definition: fd.c:2605
struct Latch * MyLatch
Definition: globals.c:62
void ResetLatch(Latch *latch)
Definition: latch.c:724
int WaitLatch(Latch *latch, int wakeEvents, long timeout, uint32 wait_event_info)
Definition: latch.c:517
#define WL_TIMEOUT
Definition: latch.h:130
#define WL_EXIT_ON_PM_DEATH
Definition: latch.h:132
#define WL_LATCH_SET
Definition: latch.h:127
static void const char fflush(stdout)
#define CHECK_FOR_INTERRUPTS()
Definition: miscadmin.h:122
#define XLOG_BACKUP_END
Definition: pg_control.h:73
static void CleanupBackupHistory(void)
Definition: xlog.c:4161
#define XLogArchivingAlways()
Definition: xlog.h:102
static void BackupHistoryFileName(char *fname, TimeLineID tli, XLogSegNo logSegNo, XLogRecPtr startpoint, int wal_segsz_bytes)
static void BackupHistoryFilePath(char *path, TimeLineID tli, XLogSegNo logSegNo, XLogRecPtr startpoint, int wal_segsz_bytes)
bool XLogArchiveIsBusy(const char *xlog)
Definition: xlogarchive.c:619
char * build_backup_content(BackupState *state, bool ishistoryfile)
Definition: xlogbackup.c:29

References AllocateFile(), Assert, BackupHistoryFileName(), BackupHistoryFilePath(), build_backup_content(), CHECK_FOR_INTERRUPTS, CleanupBackupHistory(), ControlFile, ereport, errcode(), errcode_for_file_access(), errhint(), errmsg(), ERROR, fflush(), fprintf, FreeFile(), XLogCtlData::info_lck, XLogCtlData::Insert, XLogCtlData::InsertTimeLineID, XLogCtlData::lastFpwDisableRecPtr, LW_SHARED, LWLockAcquire(), LWLockRelease(), MAXFNAMELEN, MAXPGPATH, ControlFileData::minRecoveryPoint, ControlFileData::minRecoveryPointTLI, MyLatch, NOTICE, pfree(), RecoveryInProgress(), RequestXLogSwitch(), ResetLatch(), XLogCtlInsert::runningBackups, SESSION_BACKUP_NONE, sessionBackupState, SpinLockAcquire, SpinLockRelease, WaitLatch(), wal_segment_size, WALInsertLockAcquireExclusive(), WALInsertLockRelease(), WARNING, WL_EXIT_ON_PM_DEATH, WL_LATCH_SET, WL_TIMEOUT, XLByteToPrevSeg, XLByteToSeg, XLOG_BACKUP_END, XLogArchiveIsBusy(), XLogArchivingActive, XLogArchivingAlways, XLogBeginInsert(), XLogCtl, XLogFileName(), XLogInsert(), XLogIsNeeded, and XLogRegisterData().

Referenced by perform_base_backup(), and pg_backup_stop().

◆ get_backup_status()

SessionBackupState get_backup_status ( void  )

Definition at line 9101 of file xlog.c.

9102{
9103 return sessionBackupState;
9104}

References sessionBackupState.

Referenced by pg_backup_start(), pg_backup_stop(), and SendBaseBackup().

◆ get_sync_bit()

static int get_sync_bit ( int  method)
static

Definition at line 8593 of file xlog.c.

8594{
8595 int o_direct_flag = 0;
8596
8597 /*
8598 * Use O_DIRECT if requested, except in walreceiver process. The WAL
8599 * written by walreceiver is normally read by the startup process soon
8600 * after it's written. Also, walreceiver performs unaligned writes, which
8601 * don't work with O_DIRECT, so it is required for correctness too.
8602 */
8604 o_direct_flag = PG_O_DIRECT;
8605
8606 /* If fsync is disabled, never open in sync mode */
8607 if (!enableFsync)
8608 return o_direct_flag;
8609
8610 switch (method)
8611 {
8612 /*
8613 * enum values for all sync options are defined even if they are
8614 * not supported on the current platform. But if not, they are
8615 * not included in the enum option array, and therefore will never
8616 * be seen here.
8617 */
8621 return o_direct_flag;
8622#ifdef O_SYNC
8624 return O_SYNC | o_direct_flag;
8625#endif
8626#ifdef O_DSYNC
8628 return O_DSYNC | o_direct_flag;
8629#endif
8630 default:
8631 /* can't happen (unless we are out of sync with option array) */
8632 elog(ERROR, "unrecognized \"wal_sync_method\": %d", method);
8633 return 0; /* silence warning */
8634 }
8635}
int io_direct_flags
Definition: fd.c:167
#define IO_DIRECT_WAL
Definition: fd.h:55
#define PG_O_DIRECT
Definition: fd.h:97
bool enableFsync
Definition: globals.c:128
#define AmWalReceiverProcess()
Definition: miscadmin.h:389
#define O_DSYNC
Definition: win32_port.h:352
@ WAL_SYNC_METHOD_OPEN
Definition: xlog.h:26
@ WAL_SYNC_METHOD_FDATASYNC
Definition: xlog.h:25
@ WAL_SYNC_METHOD_FSYNC_WRITETHROUGH
Definition: xlog.h:27
@ WAL_SYNC_METHOD_OPEN_DSYNC
Definition: xlog.h:28
@ WAL_SYNC_METHOD_FSYNC
Definition: xlog.h:24

References AmWalReceiverProcess, elog, enableFsync, ERROR, io_direct_flags, IO_DIRECT_WAL, O_DSYNC, PG_O_DIRECT, WAL_SYNC_METHOD_FDATASYNC, WAL_SYNC_METHOD_FSYNC, WAL_SYNC_METHOD_FSYNC_WRITETHROUGH, WAL_SYNC_METHOD_OPEN, and WAL_SYNC_METHOD_OPEN_DSYNC.

Referenced by assign_wal_sync_method(), XLogFileInit(), XLogFileInitInternal(), and XLogFileOpen().

◆ GetActiveWalLevelOnStandby()

WalLevel GetActiveWalLevelOnStandby ( void  )

Definition at line 4859 of file xlog.c.

4860{
4861 return ControlFile->wal_level;
4862}

References ControlFile, and ControlFileData::wal_level.

Referenced by CheckLogicalDecodingRequirements().

◆ GetFakeLSNForUnloggedRel()

XLogRecPtr GetFakeLSNForUnloggedRel ( void  )

Definition at line 4604 of file xlog.c.

4605{
4607}
static uint64 pg_atomic_fetch_add_u64(volatile pg_atomic_uint64 *ptr, int64 add_)
Definition: atomics.h:522

References pg_atomic_fetch_add_u64(), XLogCtlData::unloggedLSN, and XLogCtl.

Referenced by gistGetFakeLSN().

◆ GetFlushRecPtr()

XLogRecPtr GetFlushRecPtr ( TimeLineID insertTLI)

◆ GetFullPageWriteInfo()

void GetFullPageWriteInfo ( XLogRecPtr RedoRecPtr_p,
bool *  doPageWrites_p 
)

Definition at line 6467 of file xlog.c.

6468{
6469 *RedoRecPtr_p = RedoRecPtr;
6470 *doPageWrites_p = doPageWrites;
6471}
static bool doPageWrites
Definition: xlog.c:286

References doPageWrites, and RedoRecPtr.

Referenced by XLogCheckBufferNeedsBackup(), and XLogInsert().

◆ GetInsertRecPtr()

XLogRecPtr GetInsertRecPtr ( void  )

Definition at line 6482 of file xlog.c.

6483{
6484 XLogRecPtr recptr;
6485
6487 recptr = XLogCtl->LogwrtRqst.Write;
6489
6490 return recptr;
6491}

References XLogCtlData::info_lck, XLogCtlData::LogwrtRqst, SpinLockAcquire, SpinLockRelease, XLogwrtRqst::Write, and XLogCtl.

Referenced by CheckpointerMain(), gistvacuumscan(), and IsCheckpointOnSchedule().

◆ GetLastImportantRecPtr()

XLogRecPtr GetLastImportantRecPtr ( void  )

Definition at line 6556 of file xlog.c.

6557{
6559 int i;
6560
6561 for (i = 0; i < NUM_XLOGINSERT_LOCKS; i++)
6562 {
6563 XLogRecPtr last_important;
6564
6565 /*
6566 * Need to take a lock to prevent torn reads of the LSN, which are
6567 * possible on some of the supported platforms. WAL insert locks only
6568 * support exclusive mode, so we have to use that.
6569 */
6571 last_important = WALInsertLocks[i].l.lastImportantAt;
6572 LWLockRelease(&WALInsertLocks[i].l.lock);
6573
6574 if (res < last_important)
6575 res = last_important;
6576 }
6577
6578 return res;
6579}
int i
Definition: isn.c:72
XLogRecPtr lastImportantAt
Definition: xlog.c:371
WALInsertLock l
Definition: xlog.c:383
static WALInsertLockPadded * WALInsertLocks
Definition: xlog.c:569
#define NUM_XLOGINSERT_LOCKS
Definition: xlog.c:150

References i, InvalidXLogRecPtr, WALInsertLockPadded::l, WALInsertLock::lastImportantAt, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), NUM_XLOGINSERT_LOCKS, res, and WALInsertLocks.

Referenced by BackgroundWriterMain(), CheckArchiveTimeout(), and CreateCheckPoint().

◆ GetLastSegSwitchData()

pg_time_t GetLastSegSwitchData ( XLogRecPtr lastSwitchLSN)

Definition at line 6585 of file xlog.c.

6586{
6587 pg_time_t result;
6588
6589 /* Need WALWriteLock, but shared lock is sufficient */
6590 LWLockAcquire(WALWriteLock, LW_SHARED);
6591 result = XLogCtl->lastSegSwitchTime;
6592 *lastSwitchLSN = XLogCtl->lastSegSwitchLSN;
6593 LWLockRelease(WALWriteLock);
6594
6595 return result;
6596}
pg_time_t lastSegSwitchTime
Definition: xlog.c:467
XLogRecPtr lastSegSwitchLSN
Definition: xlog.c:468

References XLogCtlData::lastSegSwitchLSN, XLogCtlData::lastSegSwitchTime, LW_SHARED, LWLockAcquire(), LWLockRelease(), and XLogCtl.

Referenced by CheckArchiveTimeout().

◆ GetMockAuthenticationNonce()

char * GetMockAuthenticationNonce ( void  )

Definition at line 4578 of file xlog.c.

4579{
4580 Assert(ControlFile != NULL);
4582}
char mock_authentication_nonce[MOCK_AUTH_NONCE_LEN]
Definition: pg_control.h:229

References Assert, ControlFile, and ControlFileData::mock_authentication_nonce.

Referenced by scram_mock_salt().

◆ GetOldestRestartPoint()

void GetOldestRestartPoint ( XLogRecPtr oldrecptr,
TimeLineID oldtli 
)

◆ GetRecoveryState()

RecoveryState GetRecoveryState ( void  )

Definition at line 6370 of file xlog.c.

6371{
6372 RecoveryState retval;
6373
6375 retval = XLogCtl->SharedRecoveryState;
6377
6378 return retval;
6379}
RecoveryState
Definition: xlog.h:90

References XLogCtlData::info_lck, XLogCtlData::SharedRecoveryState, SpinLockAcquire, SpinLockRelease, and XLogCtl.

Referenced by XLogArchiveCheckDone().

◆ GetRedoRecPtr()

XLogRecPtr GetRedoRecPtr ( void  )

Definition at line 6437 of file xlog.c.

6438{
6439 XLogRecPtr ptr;
6440
6441 /*
6442 * The possibly not up-to-date copy in XlogCtl is enough. Even if we
6443 * grabbed a WAL insertion lock to read the authoritative value in
6444 * Insert->RedoRecPtr, someone might update it just after we've released
6445 * the lock.
6446 */
6448 ptr = XLogCtl->RedoRecPtr;
6450
6451 if (RedoRecPtr < ptr)
6452 RedoRecPtr = ptr;
6453
6454 return RedoRecPtr;
6455}

References XLogCtlData::info_lck, RedoRecPtr, XLogCtlData::RedoRecPtr, SpinLockAcquire, SpinLockRelease, and XLogCtl.

Referenced by CheckPointLogicalRewriteHeap(), CheckPointSnapBuild(), MaybeRemoveOldWalSummaries(), nextval_internal(), pgstat_before_server_shutdown(), ReplicationSlotReserveWal(), smgr_bulk_finish(), smgr_bulk_start_smgr(), XLogPageRead(), XLogSaveBufferForHint(), and XLogWrite().

◆ GetSystemIdentifier()

◆ GetWALAvailability()

WALAvailability GetWALAvailability ( XLogRecPtr  targetLSN)

Definition at line 7869 of file xlog.c.

7870{
7871 XLogRecPtr currpos; /* current write LSN */
7872 XLogSegNo currSeg; /* segid of currpos */
7873 XLogSegNo targetSeg; /* segid of targetLSN */
7874 XLogSegNo oldestSeg; /* actual oldest segid */
7875 XLogSegNo oldestSegMaxWalSize; /* oldest segid kept by max_wal_size */
7876 XLogSegNo oldestSlotSeg; /* oldest segid kept by slot */
7877 uint64 keepSegs;
7878
7879 /*
7880 * slot does not reserve WAL. Either deactivated, or has never been active
7881 */
7882 if (XLogRecPtrIsInvalid(targetLSN))
7883 return WALAVAIL_INVALID_LSN;
7884
7885 /*
7886 * Calculate the oldest segment currently reserved by all slots,
7887 * considering wal_keep_size and max_slot_wal_keep_size. Initialize
7888 * oldestSlotSeg to the current segment.
7889 */
7890 currpos = GetXLogWriteRecPtr();
7891 XLByteToSeg(currpos, oldestSlotSeg, wal_segment_size);
7892 KeepLogSeg(currpos, &oldestSlotSeg);
7893
7894 /*
7895 * Find the oldest extant segment file. We get 1 until checkpoint removes
7896 * the first WAL segment file since startup, which causes the status being
7897 * wrong under certain abnormal conditions but that doesn't actually harm.
7898 */
7899 oldestSeg = XLogGetLastRemovedSegno() + 1;
7900
7901 /* calculate oldest segment by max_wal_size */
7902 XLByteToSeg(currpos, currSeg, wal_segment_size);
7904
7905 if (currSeg > keepSegs)
7906 oldestSegMaxWalSize = currSeg - keepSegs;
7907 else
7908 oldestSegMaxWalSize = 1;
7909
7910 /* the segment we care about */
7911 XLByteToSeg(targetLSN, targetSeg, wal_segment_size);
7912
7913 /*
7914 * No point in returning reserved or extended status values if the
7915 * targetSeg is known to be lost.
7916 */
7917 if (targetSeg >= oldestSlotSeg)
7918 {
7919 /* show "reserved" when targetSeg is within max_wal_size */
7920 if (targetSeg >= oldestSegMaxWalSize)
7921 return WALAVAIL_RESERVED;
7922
7923 /* being retained by slots exceeding max_wal_size */
7924 return WALAVAIL_EXTENDED;
7925 }
7926
7927 /* WAL segments are no longer retained but haven't been removed yet */
7928 if (targetSeg >= oldestSeg)
7929 return WALAVAIL_UNRESERVED;
7930
7931 /* Definitely lost */
7932 return WALAVAIL_REMOVED;
7933}
XLogSegNo XLogGetLastRemovedSegno(void)
Definition: xlog.c:3758
XLogRecPtr GetXLogWriteRecPtr(void)
Definition: xlog.c:9451
@ WALAVAIL_REMOVED
Definition: xlog.h:194
@ WALAVAIL_RESERVED
Definition: xlog.h:190
@ WALAVAIL_UNRESERVED
Definition: xlog.h:193
@ WALAVAIL_EXTENDED
Definition: xlog.h:191
@ WALAVAIL_INVALID_LSN
Definition: xlog.h:189

References ConvertToXSegs, GetXLogWriteRecPtr(), KeepLogSeg(), max_wal_size_mb, wal_segment_size, WALAVAIL_EXTENDED, WALAVAIL_INVALID_LSN, WALAVAIL_REMOVED, WALAVAIL_RESERVED, WALAVAIL_UNRESERVED, XLByteToSeg, XLogGetLastRemovedSegno(), and XLogRecPtrIsInvalid.

Referenced by pg_get_replication_slots().

◆ GetWALInsertionTimeLine()

TimeLineID GetWALInsertionTimeLine ( void  )

Definition at line 6520 of file xlog.c.

6521{
6523
6524 /* Since the value can't be changing, no lock is required. */
6525 return XLogCtl->InsertTimeLineID;
6526}

References Assert, XLogCtlData::InsertTimeLineID, RECOVERY_STATE_DONE, XLogCtlData::SharedRecoveryState, and XLogCtl.

Referenced by logical_read_xlog_page(), pg_walfile_name(), pg_walfile_name_offset(), ReadReplicationSlot(), WALReadFromBuffers(), and XLogSendPhysical().

◆ GetWALInsertionTimeLineIfSet()

TimeLineID GetWALInsertionTimeLineIfSet ( void  )

Definition at line 6536 of file xlog.c.

6537{
6538 TimeLineID insertTLI;
6539
6541 insertTLI = XLogCtl->InsertTimeLineID;
6543
6544 return insertTLI;
6545}

References XLogCtlData::info_lck, XLogCtlData::InsertTimeLineID, SpinLockAcquire, SpinLockRelease, and XLogCtl.

Referenced by GetLatestLSN().

◆ GetXLogBuffer()

static char * GetXLogBuffer ( XLogRecPtr  ptr,
TimeLineID  tli 
)
static

Definition at line 1632 of file xlog.c.

1633{
1634 int idx;
1635 XLogRecPtr endptr;
1636 static uint64 cachedPage = 0;
1637 static char *cachedPos = NULL;
1638 XLogRecPtr expectedEndPtr;
1639
1640 /*
1641 * Fast path for the common case that we need to access again the same
1642 * page as last time.
1643 */
1644 if (ptr / XLOG_BLCKSZ == cachedPage)
1645 {
1646 Assert(((XLogPageHeader) cachedPos)->xlp_magic == XLOG_PAGE_MAGIC);
1647 Assert(((XLogPageHeader) cachedPos)->xlp_pageaddr == ptr - (ptr % XLOG_BLCKSZ));
1648 return cachedPos + ptr % XLOG_BLCKSZ;
1649 }
1650
1651 /*
1652 * The XLog buffer cache is organized so that a page is always loaded to a
1653 * particular buffer. That way we can easily calculate the buffer a given
1654 * page must be loaded into, from the XLogRecPtr alone.
1655 */
1656 idx = XLogRecPtrToBufIdx(ptr);
1657
1658 /*
1659 * See what page is loaded in the buffer at the moment. It could be the
1660 * page we're looking for, or something older. It can't be anything newer
1661 * - that would imply the page we're looking for has already been written
1662 * out to disk and evicted, and the caller is responsible for making sure
1663 * that doesn't happen.
1664 *
1665 * We don't hold a lock while we read the value. If someone is just about
1666 * to initialize or has just initialized the page, it's possible that we
1667 * get InvalidXLogRecPtr. That's ok, we'll grab the mapping lock (in
1668 * AdvanceXLInsertBuffer) and retry if we see anything other than the page
1669 * we're looking for.
1670 */
1671 expectedEndPtr = ptr;
1672 expectedEndPtr += XLOG_BLCKSZ - ptr % XLOG_BLCKSZ;
1673
1675 if (expectedEndPtr != endptr)
1676 {
1677 XLogRecPtr initializedUpto;
1678
1679 /*
1680 * Before calling AdvanceXLInsertBuffer(), which can block, let others
1681 * know how far we're finished with inserting the record.
1682 *
1683 * NB: If 'ptr' points to just after the page header, advertise a
1684 * position at the beginning of the page rather than 'ptr' itself. If
1685 * there are no other insertions running, someone might try to flush
1686 * up to our advertised location. If we advertised a position after
1687 * the page header, someone might try to flush the page header, even
1688 * though page might actually not be initialized yet. As the first
1689 * inserter on the page, we are effectively responsible for making
1690 * sure that it's initialized, before we let insertingAt to move past
1691 * the page header.
1692 */
1693 if (ptr % XLOG_BLCKSZ == SizeOfXLogShortPHD &&
1694 XLogSegmentOffset(ptr, wal_segment_size) > XLOG_BLCKSZ)
1695 initializedUpto = ptr - SizeOfXLogShortPHD;
1696 else if (ptr % XLOG_BLCKSZ == SizeOfXLogLongPHD &&
1697 XLogSegmentOffset(ptr, wal_segment_size) < XLOG_BLCKSZ)
1698 initializedUpto = ptr - SizeOfXLogLongPHD;
1699 else
1700 initializedUpto = ptr;
1701
1702 WALInsertLockUpdateInsertingAt(initializedUpto);
1703
1704 AdvanceXLInsertBuffer(ptr, tli, false);
1706
1707 if (expectedEndPtr != endptr)
1708 elog(PANIC, "could not find WAL buffer for %X/%X",
1709 LSN_FORMAT_ARGS(ptr));
1710 }
1711 else
1712 {
1713 /*
1714 * Make sure the initialization of the page is visible to us, and
1715 * won't arrive later to overwrite the WAL data we write on the page.
1716 */
1718 }
1719
1720 /*
1721 * Found the buffer holding this page. Return a pointer to the right
1722 * offset within the page.
1723 */
1724 cachedPage = ptr / XLOG_BLCKSZ;
1725 cachedPos = XLogCtl->pages + idx * (Size) XLOG_BLCKSZ;
1726
1727 Assert(((XLogPageHeader) cachedPos)->xlp_magic == XLOG_PAGE_MAGIC);
1728 Assert(((XLogPageHeader) cachedPos)->xlp_pageaddr == ptr - (ptr % XLOG_BLCKSZ));
1729
1730 return cachedPos + ptr % XLOG_BLCKSZ;
1731}
Datum idx(PG_FUNCTION_ARGS)
Definition: _int_op.c:259
#define pg_memory_barrier()
Definition: atomics.h:143
static void WALInsertLockUpdateInsertingAt(XLogRecPtr insertingAt)
Definition: xlog.c:1471
static void AdvanceXLInsertBuffer(XLogRecPtr upto, TimeLineID tli, bool opportunistic)
Definition: xlog.c:1985

References AdvanceXLInsertBuffer(), Assert, elog, idx(), LSN_FORMAT_ARGS, XLogCtlData::pages, PANIC, pg_atomic_read_u64(), pg_memory_barrier, SizeOfXLogLongPHD, SizeOfXLogShortPHD, wal_segment_size, WALInsertLockUpdateInsertingAt(), XLogCtlData::xlblocks, XLOG_PAGE_MAGIC, XLogCtl, XLogRecPtrToBufIdx, and XLogSegmentOffset.

Referenced by CopyXLogRecordToWAL(), and CreateOverwriteContrecordRecord().

◆ GetXLogInsertRecPtr()

XLogRecPtr GetXLogInsertRecPtr ( void  )

Definition at line 9435 of file xlog.c.

9436{
9438 uint64 current_bytepos;
9439
9440 SpinLockAcquire(&Insert->insertpos_lck);
9441 current_bytepos = Insert->CurrBytePos;
9442 SpinLockRelease(&Insert->insertpos_lck);
9443
9444 return XLogBytePosToRecPtr(current_bytepos);
9445}

References XLogCtlData::Insert, Insert(), SpinLockAcquire, SpinLockRelease, XLogBytePosToRecPtr(), and XLogCtl.

Referenced by CreateOverwriteContrecordRecord(), gistGetFakeLSN(), logical_begin_heap_rewrite(), pg_current_wal_insert_lsn(), and ReplicationSlotReserveWal().

◆ GetXLogWriteRecPtr()

XLogRecPtr GetXLogWriteRecPtr ( void  )

◆ InitControlFile()

static void InitControlFile ( uint64  sysidentifier,
uint32  data_checksum_version 
)
static

Definition at line 4204 of file xlog.c.

4205{
4206 char mock_auth_nonce[MOCK_AUTH_NONCE_LEN];
4207
4208 /*
4209 * Generate a random nonce. This is used for authentication requests that
4210 * will fail because the user does not exist. The nonce is used to create
4211 * a genuine-looking password challenge for the non-existent user, in lieu
4212 * of an actual stored password.
4213 */
4214 if (!pg_strong_random(mock_auth_nonce, MOCK_AUTH_NONCE_LEN))
4215 ereport(PANIC,
4216 (errcode(ERRCODE_INTERNAL_ERROR),
4217 errmsg("could not generate secret authorization token")));
4218
4219 memset(ControlFile, 0, sizeof(ControlFileData));
4220 /* Initialize pg_control status fields */
4221 ControlFile->system_identifier = sysidentifier;
4225
4226 /* Set important parameter values for use when replaying WAL */
4235 ControlFile->data_checksum_version = data_checksum_version;
4236}
bool track_commit_timestamp
Definition: commit_ts.c:109
#define MOCK_AUTH_NONCE_LEN
Definition: pg_control.h:28
bool pg_strong_random(void *buf, size_t len)
bool track_commit_timestamp
Definition: pg_control.h:185
bool wal_log_hints
Definition: xlog.c:123
#define FirstNormalUnloggedLSN
Definition: xlogdefs.h:36

References ControlFile, ControlFileData::data_checksum_version, DB_SHUTDOWNED, ereport, errcode(), errmsg(), FirstNormalUnloggedLSN, max_locks_per_xact, ControlFileData::max_locks_per_xact, max_prepared_xacts, ControlFileData::max_prepared_xacts, max_wal_senders, ControlFileData::max_wal_senders, max_worker_processes, ControlFileData::max_worker_processes, MaxConnections, ControlFileData::MaxConnections, MOCK_AUTH_NONCE_LEN, ControlFileData::mock_authentication_nonce, PANIC, pg_strong_random(), ControlFileData::state, ControlFileData::system_identifier, track_commit_timestamp, ControlFileData::track_commit_timestamp, ControlFileData::unloggedLSN, wal_level, ControlFileData::wal_level, wal_log_hints, and ControlFileData::wal_log_hints.

Referenced by BootStrapXLOG().

◆ InitializeWalConsistencyChecking()

void InitializeWalConsistencyChecking ( void  )

Definition at line 4784 of file xlog.c.

4785{
4787
4789 {
4790 struct config_generic *guc;
4791
4792 guc = find_option("wal_consistency_checking", false, false, ERROR);
4793
4795
4796 set_config_option_ext("wal_consistency_checking",
4798 guc->scontext, guc->source, guc->srole,
4799 GUC_ACTION_SET, true, ERROR, false);
4800
4801 /* checking should not be deferred again */
4803 }
4804}
int set_config_option_ext(const char *name, const char *value, GucContext context, GucSource source, Oid srole, GucAction action, bool changeVal, int elevel, bool is_reload)
Definition: guc.c:3382
struct config_generic * find_option(const char *name, bool create_placeholders, bool skip_errors, int elevel)
Definition: guc.c:1235
@ GUC_ACTION_SET
Definition: guc.h:199
GucContext scontext
Definition: guc_tables.h:167
GucSource source
Definition: guc_tables.h:165
char * wal_consistency_checking_string
Definition: xlog.c:125

References Assert, check_wal_consistency_checking_deferred, ERROR, find_option(), GUC_ACTION_SET, process_shared_preload_libraries_done, config_generic::scontext, set_config_option_ext(), config_generic::source, config_generic::srole, and wal_consistency_checking_string.

Referenced by PostgresSingleUserMain(), and PostmasterMain().

◆ InstallXLogFileSegment()

static bool InstallXLogFileSegment ( XLogSegNo segno,
char *  tmppath,
bool  find_free,
XLogSegNo  max_segno,
TimeLineID  tli 
)
static

Definition at line 3563 of file xlog.c.

3565{
3566 char path[MAXPGPATH];
3567 struct stat stat_buf;
3568
3569 Assert(tli != 0);
3570
3571 XLogFilePath(path, tli, *segno, wal_segment_size);
3572
3573 LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
3575 {
3576 LWLockRelease(ControlFileLock);
3577 return false;
3578 }
3579
3580 if (!find_free)
3581 {
3582 /* Force installation: get rid of any pre-existing segment file */
3583 durable_unlink(path, DEBUG1);
3584 }
3585 else
3586 {
3587 /* Find a free slot to put it in */
3588 while (stat(path, &stat_buf) == 0)
3589 {
3590 if ((*segno) >= max_segno)
3591 {
3592 /* Failed to find a free slot within specified range */
3593 LWLockRelease(ControlFileLock);
3594 return false;
3595 }
3596 (*segno)++;
3597 XLogFilePath(path, tli, *segno, wal_segment_size);
3598 }
3599 }
3600
3601 Assert(access(path, F_OK) != 0 && errno == ENOENT);
3602 if (durable_rename(tmppath, path, LOG) != 0)
3603 {
3604 LWLockRelease(ControlFileLock);
3605 /* durable_rename already emitted log message */
3606 return false;
3607 }
3608
3609 LWLockRelease(ControlFileLock);
3610
3611 return true;
3612}
int durable_unlink(const char *fname, int elevel)
Definition: fd.c:871
short access
Definition: preproc-type.c:36
bool InstallXLogFileSegmentActive
Definition: xlog.c:526
#define stat
Definition: win32_port.h:284

References Assert, DEBUG1, durable_rename(), durable_unlink(), XLogCtlData::InstallXLogFileSegmentActive, LOG, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), MAXPGPATH, stat, wal_segment_size, XLogCtl, and XLogFilePath().

Referenced by RemoveXlogFile(), XLogFileCopy(), and XLogFileInitInternal().

◆ IsInstallXLogFileSegmentActive()

bool IsInstallXLogFileSegmentActive ( void  )

Definition at line 9492 of file xlog.c.

9493{
9494 bool result;
9495
9496 LWLockAcquire(ControlFileLock, LW_SHARED);
9498 LWLockRelease(ControlFileLock);
9499
9500 return result;
9501}

References XLogCtlData::InstallXLogFileSegmentActive, LW_SHARED, LWLockAcquire(), LWLockRelease(), and XLogCtl.

Referenced by XLogFileRead().

◆ issue_xlog_fsync()

void issue_xlog_fsync ( int  fd,
XLogSegNo  segno,
TimeLineID  tli 
)

Definition at line 8683 of file xlog.c.

8684{
8685 char *msg = NULL;
8687
8688 Assert(tli != 0);
8689
8690 /*
8691 * Quick exit if fsync is disabled or write() has already synced the WAL
8692 * file.
8693 */
8694 if (!enableFsync ||
8697 return;
8698
8699 /* Measure I/O timing to sync the WAL file */
8702 else
8704
8705 pgstat_report_wait_start(WAIT_EVENT_WAL_SYNC);
8706 switch (wal_sync_method)
8707 {
8709 if (pg_fsync_no_writethrough(fd) != 0)
8710 msg = _("could not fsync file \"%s\": %m");
8711 break;
8712#ifdef HAVE_FSYNC_WRITETHROUGH
8714 if (pg_fsync_writethrough(fd) != 0)
8715 msg = _("could not fsync write-through file \"%s\": %m");
8716 break;
8717#endif
8719 if (pg_fdatasync(fd) != 0)
8720 msg = _("could not fdatasync file \"%s\": %m");
8721 break;
8724 /* not reachable */
8725 Assert(false);
8726 break;
8727 default:
8728 ereport(PANIC,
8729 errcode(ERRCODE_INVALID_PARAMETER_VALUE),
8730 errmsg_internal("unrecognized \"wal_sync_method\": %d", wal_sync_method));
8731 break;
8732 }
8733
8734 /* PANIC if failed to fsync */
8735 if (msg)
8736 {
8737 char xlogfname[MAXFNAMELEN];
8738 int save_errno = errno;
8739
8740 XLogFileName(xlogfname, tli, segno, wal_segment_size);
8741 errno = save_errno;
8742 ereport(PANIC,
8744 errmsg(msg, xlogfname)));
8745 }
8746
8748
8749 /*
8750 * Increment the I/O timing and the number of times WAL files were synced.
8751 */
8753 {
8754 instr_time end;
8755
8758 }
8759
8761}
#define _(x)
Definition: elog.c:90
int pg_fsync_no_writethrough(int fd)
Definition: fd.c:440
int pg_fdatasync(int fd)
Definition: fd.c:479
int pg_fsync_writethrough(int fd)
Definition: fd.c:460
return str start
#define INSTR_TIME_SET_CURRENT(t)
Definition: instr_time.h:122
#define INSTR_TIME_SET_ZERO(t)
Definition: instr_time.h:172
#define INSTR_TIME_ACCUM_DIFF(x, y, z)
Definition: instr_time.h:184
static int fd(const char *x, int i)
Definition: preproc-init.c:105
instr_time wal_sync_time
Definition: pgstat.h:523
PgStat_Counter wal_sync
Definition: pgstat.h:521
bool track_wal_io_timing
Definition: xlog.c:137

References _, Assert, enableFsync, ereport, errcode(), errcode_for_file_access(), errmsg(), errmsg_internal(), fd(), INSTR_TIME_ACCUM_DIFF, INSTR_TIME_SET_CURRENT, INSTR_TIME_SET_ZERO, MAXFNAMELEN, PANIC, PendingWalStats, pg_fdatasync(), pg_fsync_no_writethrough(), pg_fsync_writethrough(), pgstat_report_wait_end(), pgstat_report_wait_start(), start, track_wal_io_timing, wal_segment_size, PgStat_PendingWalStats::wal_sync, wal_sync_method, WAL_SYNC_METHOD_FDATASYNC, WAL_SYNC_METHOD_FSYNC, WAL_SYNC_METHOD_FSYNC_WRITETHROUGH, WAL_SYNC_METHOD_OPEN, WAL_SYNC_METHOD_OPEN_DSYNC, PgStat_PendingWalStats::wal_sync_time, and XLogFileName().

Referenced by XLogWalRcvFlush(), and XLogWrite().

◆ KeepLogSeg()

static void KeepLogSeg ( XLogRecPtr  recptr,
XLogSegNo logSegNo 
)
static

Definition at line 7953 of file xlog.c.

7954{
7955 XLogSegNo currSegNo;
7956 XLogSegNo segno;
7957 XLogRecPtr keep;
7958
7959 XLByteToSeg(recptr, currSegNo, wal_segment_size);
7960 segno = currSegNo;
7961
7962 /*
7963 * Calculate how many segments are kept by slots first, adjusting for
7964 * max_slot_wal_keep_size.
7965 */
7967 if (keep != InvalidXLogRecPtr && keep < recptr)
7968 {
7969 XLByteToSeg(keep, segno, wal_segment_size);
7970
7971 /* Cap by max_slot_wal_keep_size ... */
7973 {
7974 uint64 slot_keep_segs;
7975
7976 slot_keep_segs =
7978
7979 if (currSegNo - segno > slot_keep_segs)
7980 segno = currSegNo - slot_keep_segs;
7981 }
7982 }
7983
7984 /*
7985 * If WAL summarization is in use, don't remove WAL that has yet to be
7986 * summarized.
7987 */
7988 keep = GetOldestUnsummarizedLSN(NULL, NULL);
7989 if (keep != InvalidXLogRecPtr)
7990 {
7991 XLogSegNo unsummarized_segno;
7992
7993 XLByteToSeg(keep, unsummarized_segno, wal_segment_size);
7994 if (unsummarized_segno < segno)
7995 segno = unsummarized_segno;
7996 }
7997
7998 /* but, keep at least wal_keep_size if that's set */
7999 if (wal_keep_size_mb > 0)
8000 {
8001 uint64 keep_segs;
8002
8004 if (currSegNo - segno < keep_segs)
8005 {
8006 /* avoid underflow, don't go below 1 */
8007 if (currSegNo <= keep_segs)
8008 segno = 1;
8009 else
8010 segno = currSegNo - keep_segs;
8011 }
8012 }
8013
8014 /* don't delete WAL segments newer than the calculated segment */
8015 if (segno < *logSegNo)
8016 *logSegNo = segno;
8017}
XLogRecPtr GetOldestUnsummarizedLSN(TimeLineID *tli, bool *lsn_is_exact)
int wal_keep_size_mb
Definition: xlog.c:116
static XLogRecPtr XLogGetReplicationSlotMinimumLSN(void)
Definition: xlog.c:2701
int max_slot_wal_keep_size_mb
Definition: xlog.c:135

References ConvertToXSegs, GetOldestUnsummarizedLSN(), InvalidXLogRecPtr, max_slot_wal_keep_size_mb, wal_keep_size_mb, wal_segment_size, XLByteToSeg, and XLogGetReplicationSlotMinimumLSN().

Referenced by CreateCheckPoint(), CreateRestartPoint(), and GetWALAvailability().

◆ LocalProcessControlFile()

void LocalProcessControlFile ( bool  reset)

Definition at line 4846 of file xlog.c.

4847{
4848 Assert(reset || ControlFile == NULL);
4851}
void reset(void)
Definition: sql-declare.c:600

References Assert, ControlFile, palloc(), ReadControlFile(), and reset().

Referenced by PostgresSingleUserMain(), PostmasterMain(), and PostmasterStateMachine().

◆ LocalSetXLogInsertAllowed()

static int LocalSetXLogInsertAllowed ( void  )
static

Definition at line 6422 of file xlog.c.

6423{
6424 int oldXLogAllowed = LocalXLogInsertAllowed;
6425
6427
6428 return oldXLogAllowed;
6429}

References LocalXLogInsertAllowed.

Referenced by CreateCheckPoint(), and StartupXLOG().

◆ LogCheckpointEnd()

static void LogCheckpointEnd ( bool  restartpoint)
static

Definition at line 6681 of file xlog.c.

6682{
6683 long write_msecs,
6684 sync_msecs,
6685 total_msecs,
6686 longest_msecs,
6687 average_msecs;
6688 uint64 average_sync_time;
6689
6691
6694
6697
6698 /* Accumulate checkpoint timing summary data, in milliseconds. */
6699 PendingCheckpointerStats.write_time += write_msecs;
6700 PendingCheckpointerStats.sync_time += sync_msecs;
6701
6702 /*
6703 * All of the published timing statistics are accounted for. Only
6704 * continue if a log message is to be written.
6705 */
6706 if (!log_checkpoints)
6707 return;
6708
6711
6712 /*
6713 * Timing values returned from CheckpointStats are in microseconds.
6714 * Convert to milliseconds for consistent printing.
6715 */
6716 longest_msecs = (long) ((CheckpointStats.ckpt_longest_sync + 999) / 1000);
6717
6718 average_sync_time = 0;
6720 average_sync_time = CheckpointStats.ckpt_agg_sync_time /
6722 average_msecs = (long) ((average_sync_time + 999) / 1000);
6723
6724 /*
6725 * ControlFileLock is not required to see ControlFile->checkPoint and
6726 * ->checkPointCopy here as we are the only updator of those variables at
6727 * this moment.
6728 */
6729 if (restartpoint)
6730 ereport(LOG,
6731 (errmsg("restartpoint complete: wrote %d buffers (%.1f%%), "
6732 "wrote %d SLRU buffers; %d WAL file(s) added, "
6733 "%d removed, %d recycled; write=%ld.%03d s, "
6734 "sync=%ld.%03d s, total=%ld.%03d s; sync files=%d, "
6735 "longest=%ld.%03d s, average=%ld.%03d s; distance=%d kB, "
6736 "estimate=%d kB; lsn=%X/%X, redo lsn=%X/%X",
6743 write_msecs / 1000, (int) (write_msecs % 1000),
6744 sync_msecs / 1000, (int) (sync_msecs % 1000),
6745 total_msecs / 1000, (int) (total_msecs % 1000),
6747 longest_msecs / 1000, (int) (longest_msecs % 1000),
6748 average_msecs / 1000, (int) (average_msecs % 1000),
6749 (int) (PrevCheckPointDistance / 1024.0),
6750 (int) (CheckPointDistanceEstimate / 1024.0),
6753 else
6754 ereport(LOG,
6755 (errmsg("checkpoint complete: wrote %d buffers (%.1f%%), "
6756 "wrote %d SLRU buffers; %d WAL file(s) added, "
6757 "%d removed, %d recycled; write=%ld.%03d s, "
6758 "sync=%ld.%03d s, total=%ld.%03d s; sync files=%d, "
6759 "longest=%ld.%03d s, average=%ld.%03d s; distance=%d kB, "
6760 "estimate=%d kB; lsn=%X/%X, redo lsn=%X/%X",
6767 write_msecs / 1000, (int) (write_msecs % 1000),
6768 sync_msecs / 1000, (int) (sync_msecs % 1000),
6769 total_msecs / 1000, (int) (total_msecs % 1000),
6771 longest_msecs / 1000, (int) (longest_msecs % 1000),
6772 average_msecs / 1000, (int) (average_msecs % 1000),
6773 (int) (PrevCheckPointDistance / 1024.0),
6774 (int) (CheckPointDistanceEstimate / 1024.0),
6777}
long TimestampDifferenceMilliseconds(TimestampTz start_time, TimestampTz stop_time)
Definition: timestamp.c:1756
PgStat_CheckpointerStats PendingCheckpointerStats
uint64 ckpt_agg_sync_time
Definition: xlog.h:176
uint64 ckpt_longest_sync
Definition: xlog.h:175
TimestampTz ckpt_end_t
Definition: xlog.h:165
int ckpt_slru_written
Definition: xlog.h:168
int ckpt_sync_rels
Definition: xlog.h:174
PgStat_Counter sync_time
Definition: pgstat.h:318
PgStat_Counter write_time
Definition: pgstat.h:317
static double CheckPointDistanceEstimate
Definition: xlog.c:159
static double PrevCheckPointDistance
Definition: xlog.c:160

References ControlFileData::checkPoint, ControlFileData::checkPointCopy, CheckPointDistanceEstimate, CheckpointStats, CheckpointStatsData::ckpt_agg_sync_time, CheckpointStatsData::ckpt_bufs_written, CheckpointStatsData::ckpt_end_t, CheckpointStatsData::ckpt_longest_sync, CheckpointStatsData::ckpt_segs_added, CheckpointStatsData::ckpt_segs_recycled, CheckpointStatsData::ckpt_segs_removed, CheckpointStatsData::ckpt_slru_written, CheckpointStatsData::ckpt_start_t, CheckpointStatsData::ckpt_sync_end_t, CheckpointStatsData::ckpt_sync_rels, CheckpointStatsData::ckpt_sync_t, CheckpointStatsData::ckpt_write_t, ControlFile, ereport, errmsg(), GetCurrentTimestamp(), LOG, log_checkpoints, LSN_FORMAT_ARGS, NBuffers, PendingCheckpointerStats, PrevCheckPointDistance, CheckPoint::redo, PgStat_CheckpointerStats::sync_time, TimestampDifferenceMilliseconds(), and PgStat_CheckpointerStats::write_time.

Referenced by CreateCheckPoint(), and CreateRestartPoint().

◆ LogCheckpointStart()

static void LogCheckpointStart ( int  flags,
bool  restartpoint 
)
static

Definition at line 6649 of file xlog.c.

6650{
6651 if (restartpoint)
6652 ereport(LOG,
6653 /* translator: the placeholders show checkpoint options */
6654 (errmsg("restartpoint starting:%s%s%s%s%s%s%s%s",
6655 (flags & CHECKPOINT_IS_SHUTDOWN) ? " shutdown" : "",
6656 (flags & CHECKPOINT_END_OF_RECOVERY) ? " end-of-recovery" : "",
6657 (flags & CHECKPOINT_IMMEDIATE) ? " immediate" : "",
6658 (flags & CHECKPOINT_FORCE) ? " force" : "",
6659 (flags & CHECKPOINT_WAIT) ? " wait" : "",
6660 (flags & CHECKPOINT_CAUSE_XLOG) ? " wal" : "",
6661 (flags & CHECKPOINT_CAUSE_TIME) ? " time" : "",
6662 (flags & CHECKPOINT_FLUSH_ALL) ? " flush-all" : "")));
6663 else
6664 ereport(LOG,
6665 /* translator: the placeholders show checkpoint options */
6666 (errmsg("checkpoint starting:%s%s%s%s%s%s%s%s",
6667 (flags & CHECKPOINT_IS_SHUTDOWN) ? " shutdown" : "",
6668 (flags & CHECKPOINT_END_OF_RECOVERY) ? " end-of-recovery" : "",
6669 (flags & CHECKPOINT_IMMEDIATE) ? " immediate" : "",
6670 (flags & CHECKPOINT_FORCE) ? " force" : "",
6671 (flags & CHECKPOINT_WAIT) ? " wait" : "",
6672 (flags & CHECKPOINT_CAUSE_XLOG) ? " wal" : "",
6673 (flags & CHECKPOINT_CAUSE_TIME) ? " time" : "",
6674 (flags & CHECKPOINT_FLUSH_ALL) ? " flush-all" : "")));
6675}
#define CHECKPOINT_CAUSE_XLOG
Definition: xlog.h:148
#define CHECKPOINT_FLUSH_ALL
Definition: xlog.h:143
#define CHECKPOINT_CAUSE_TIME
Definition: xlog.h:149

References CHECKPOINT_CAUSE_TIME, CHECKPOINT_CAUSE_XLOG, CHECKPOINT_END_OF_RECOVERY, CHECKPOINT_FLUSH_ALL, CHECKPOINT_FORCE, CHECKPOINT_IMMEDIATE, CHECKPOINT_IS_SHUTDOWN, CHECKPOINT_WAIT, ereport, errmsg(), and LOG.

Referenced by CreateCheckPoint(), and CreateRestartPoint().

◆ PerformRecoveryXLogAction()

static bool PerformRecoveryXLogAction ( void  )
static

Definition at line 6284 of file xlog.c.

6285{
6286 bool promoted = false;
6287
6288 /*
6289 * Perform a checkpoint to update all our recovery activity to disk.
6290 *
6291 * Note that we write a shutdown checkpoint rather than an on-line one.
6292 * This is not particularly critical, but since we may be assigning a new
6293 * TLI, using a shutdown checkpoint allows us to have the rule that TLI
6294 * only changes in shutdown checkpoints, which allows some extra error
6295 * checking in xlog_redo.
6296 *
6297 * In promotion, only create a lightweight end-of-recovery record instead
6298 * of a full checkpoint. A checkpoint is requested later, after we're
6299 * fully out of recovery mode and already accepting queries.
6300 */
6303 {
6304 promoted = true;
6305
6306 /*
6307 * Insert a special WAL record to mark the end of recovery, since we
6308 * aren't doing a checkpoint. That means that the checkpointer process
6309 * may likely be in the middle of a time-smoothed restartpoint and
6310 * could continue to be for minutes after this. That sounds strange,
6311 * but the effect is roughly the same and it would be stranger to try
6312 * to come out of the restartpoint and then checkpoint. We request a
6313 * checkpoint later anyway, just for safety.
6314 */
6316 }
6317 else
6318 {
6322 }
6323
6324 return promoted;
6325}
static void CreateEndOfRecoveryRecord(void)
Definition: xlog.c:7375
bool PromoteIsTriggered(void)

References ArchiveRecoveryRequested, CHECKPOINT_END_OF_RECOVERY, CHECKPOINT_IMMEDIATE, CHECKPOINT_WAIT, CreateEndOfRecoveryRecord(), IsUnderPostmaster, PromoteIsTriggered(), and RequestCheckpoint().

Referenced by StartupXLOG().

◆ PreallocXlogFiles()

static void PreallocXlogFiles ( XLogRecPtr  endptr,
TimeLineID  tli 
)
static

Definition at line 3690 of file xlog.c.

3691{
3692 XLogSegNo _logSegNo;
3693 int lf;
3694 bool added;
3695 char path[MAXPGPATH];
3696 uint64 offset;
3697
3699 return; /* unlocked check says no */
3700
3701 XLByteToPrevSeg(endptr, _logSegNo, wal_segment_size);
3702 offset = XLogSegmentOffset(endptr - 1, wal_segment_size);
3703 if (offset >= (uint32) (0.75 * wal_segment_size))
3704 {
3705 _logSegNo++;
3706 lf = XLogFileInitInternal(_logSegNo, tli, &added, path);
3707 if (lf >= 0)
3708 close(lf);
3709 if (added)
3711 }
3712}
static int XLogFileInitInternal(XLogSegNo logsegno, TimeLineID logtli, bool *added, char *path)
Definition: xlog.c:3210

References CheckpointStats, CheckpointStatsData::ckpt_segs_added, close, XLogCtlData::InstallXLogFileSegmentActive, MAXPGPATH, wal_segment_size, XLByteToPrevSeg, XLogCtl, XLogFileInitInternal(), and XLogSegmentOffset.

Referenced by CreateCheckPoint(), CreateRestartPoint(), and StartupXLOG().

◆ ReachedEndOfBackup()

void ReachedEndOfBackup ( XLogRecPtr  EndRecPtr,
TimeLineID  tli 
)

Definition at line 6247 of file xlog.c.

6248{
6249 /*
6250 * We have reached the end of base backup, as indicated by pg_control. The
6251 * data on disk is now consistent (unless minRecoveryPoint is further
6252 * ahead, which can happen if we crashed during previous recovery). Reset
6253 * backupStartPoint and backupEndPoint, and update minRecoveryPoint to
6254 * make sure we don't allow starting up at an earlier point even if
6255 * recovery is stopped and restarted soon after this.
6256 */
6257 LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
6258
6259 if (ControlFile->minRecoveryPoint < EndRecPtr)
6260 {
6261 ControlFile->minRecoveryPoint = EndRecPtr;
6263 }
6264
6269
6270 LWLockRelease(ControlFileLock);
6271}
XLogRecPtr backupStartPoint
Definition: pg_control.h:170
bool backupEndRequired
Definition: pg_control.h:172
XLogRecPtr backupEndPoint
Definition: pg_control.h:171

References ControlFileData::backupEndPoint, ControlFileData::backupEndRequired, ControlFileData::backupStartPoint, ControlFile, InvalidXLogRecPtr, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), ControlFileData::minRecoveryPoint, ControlFileData::minRecoveryPointTLI, and UpdateControlFile().

Referenced by CheckRecoveryConsistency().

◆ ReadControlFile()

static void ReadControlFile ( void  )
static

Definition at line 4321 of file xlog.c.

4322{
4323 pg_crc32c crc;
4324 int fd;
4325 char wal_segsz_str[20];
4326 int r;
4327
4328 /*
4329 * Read data...
4330 */
4332 O_RDWR | PG_BINARY);
4333 if (fd < 0)
4334 ereport(PANIC,
4336 errmsg("could not open file \"%s\": %m",
4338
4339 pgstat_report_wait_start(WAIT_EVENT_CONTROL_FILE_READ);
4340 r = read(fd, ControlFile, sizeof(ControlFileData));
4341 if (r != sizeof(ControlFileData))
4342 {
4343 if (r < 0)
4344 ereport(PANIC,
4346 errmsg("could not read file \"%s\": %m",
4348 else
4349 ereport(PANIC,
4351 errmsg("could not read file \"%s\": read %d of %zu",
4352 XLOG_CONTROL_FILE, r, sizeof(ControlFileData))));
4353 }
4355
4356 close(fd);
4357
4358 /*
4359 * Check for expected pg_control format version. If this is wrong, the
4360 * CRC check will likely fail because we'll be checking the wrong number
4361 * of bytes. Complaining about wrong version will probably be more
4362 * enlightening than complaining about wrong CRC.
4363 */
4364
4366 ereport(FATAL,
4367 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4368 errmsg("database files are incompatible with server"),
4369 errdetail("The database cluster was initialized with PG_CONTROL_VERSION %d (0x%08x),"
4370 " but the server was compiled with PG_CONTROL_VERSION %d (0x%08x).",
4373 errhint("This could be a problem of mismatched byte ordering. It looks like you need to initdb.")));
4374
4376 ereport(FATAL,
4377 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4378 errmsg("database files are incompatible with server"),
4379 errdetail("The database cluster was initialized with PG_CONTROL_VERSION %d,"
4380 " but the server was compiled with PG_CONTROL_VERSION %d.",
4382 errhint("It looks like you need to initdb.")));
4383
4384 /* Now check the CRC. */
4387 (char *) ControlFile,
4388 offsetof(ControlFileData, crc));
4389 FIN_CRC32C(crc);
4390
4391 if (!EQ_CRC32C(crc, ControlFile->crc))
4392 ereport(FATAL,
4393 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4394 errmsg("incorrect checksum in control file")));
4395
4396 /*
4397 * Do compatibility checking immediately. If the database isn't
4398 * compatible with the backend executable, we want to abort before we can
4399 * possibly do any damage.
4400 */
4402 ereport(FATAL,
4403 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4404 errmsg("database files are incompatible with server"),
4405 /* translator: %s is a variable name and %d is its value */
4406 errdetail("The database cluster was initialized with %s %d,"
4407 " but the server was compiled with %s %d.",
4408 "CATALOG_VERSION_NO", ControlFile->catalog_version_no,
4409 "CATALOG_VERSION_NO", CATALOG_VERSION_NO),
4410 errhint("It looks like you need to initdb.")));
4411 if (ControlFile->maxAlign != MAXIMUM_ALIGNOF)
4412 ereport(FATAL,
4413 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4414 errmsg("database files are incompatible with server"),
4415 /* translator: %s is a variable name and %d is its value */
4416 errdetail("The database cluster was initialized with %s %d,"
4417 " but the server was compiled with %s %d.",
4418 "MAXALIGN", ControlFile->maxAlign,
4419 "MAXALIGN", MAXIMUM_ALIGNOF),
4420 errhint("It looks like you need to initdb.")));
4422 ereport(FATAL,
4423 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4424 errmsg("database files are incompatible with server"),
4425 errdetail("The database cluster appears to use a different floating-point number format than the server executable."),
4426 errhint("It looks like you need to initdb.")));
4427 if (ControlFile->blcksz != BLCKSZ)
4428 ereport(FATAL,
4429 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4430 errmsg("database files are incompatible with server"),
4431 /* translator: %s is a variable name and %d is its value */
4432 errdetail("The database cluster was initialized with %s %d,"
4433 " but the server was compiled with %s %d.",
4434 "BLCKSZ", ControlFile->blcksz,
4435 "BLCKSZ", BLCKSZ),
4436 errhint("It looks like you need to recompile or initdb.")));
4437 if (ControlFile->relseg_size != RELSEG_SIZE)
4438 ereport(FATAL,
4439 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4440 errmsg("database files are incompatible with server"),
4441 /* translator: %s is a variable name and %d is its value */
4442 errdetail("The database cluster was initialized with %s %d,"
4443 " but the server was compiled with %s %d.",
4444 "RELSEG_SIZE", ControlFile->relseg_size,
4445 "RELSEG_SIZE", RELSEG_SIZE),
4446 errhint("It looks like you need to recompile or initdb.")));
4447 if (ControlFile->xlog_blcksz != XLOG_BLCKSZ)
4448 ereport(FATAL,
4449 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4450 errmsg("database files are incompatible with server"),
4451 /* translator: %s is a variable name and %d is its value */
4452 errdetail("The database cluster was initialized with %s %d,"
4453 " but the server was compiled with %s %d.",
4454 "XLOG_BLCKSZ", ControlFile->xlog_blcksz,
4455 "XLOG_BLCKSZ", XLOG_BLCKSZ),
4456 errhint("It looks like you need to recompile or initdb.")));
4458 ereport(FATAL,
4459 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4460 errmsg("database files are incompatible with server"),
4461 /* translator: %s is a variable name and %d is its value */
4462 errdetail("The database cluster was initialized with %s %d,"
4463 " but the server was compiled with %s %d.",
4464 "NAMEDATALEN", ControlFile->nameDataLen,
4465 "NAMEDATALEN", NAMEDATALEN),
4466 errhint("It looks like you need to recompile or initdb.")));
4468 ereport(FATAL,
4469 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4470 errmsg("database files are incompatible with server"),
4471 /* translator: %s is a variable name and %d is its value */
4472 errdetail("The database cluster was initialized with %s %d,"
4473 " but the server was compiled with %s %d.",
4474 "INDEX_MAX_KEYS", ControlFile->indexMaxKeys,
4475 "INDEX_MAX_KEYS", INDEX_MAX_KEYS),
4476 errhint("It looks like you need to recompile or initdb.")));
4478 ereport(FATAL,
4479 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4480 errmsg("database files are incompatible with server"),
4481 /* translator: %s is a variable name and %d is its value */
4482 errdetail("The database cluster was initialized with %s %d,"
4483 " but the server was compiled with %s %d.",
4484 "TOAST_MAX_CHUNK_SIZE", ControlFile->toast_max_chunk_size,
4485 "TOAST_MAX_CHUNK_SIZE", (int) TOAST_MAX_CHUNK_SIZE),
4486 errhint("It looks like you need to recompile or initdb.")));
4488 ereport(FATAL,
4489 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4490 errmsg("database files are incompatible with server"),
4491 /* translator: %s is a variable name and %d is its value */
4492 errdetail("The database cluster was initialized with %s %d,"
4493 " but the server was compiled with %s %d.",
4494 "LOBLKSIZE", ControlFile->loblksize,
4495 "LOBLKSIZE", (int) LOBLKSIZE),
4496 errhint("It looks like you need to recompile or initdb.")));
4497
4498#ifdef USE_FLOAT8_BYVAL
4499 if (ControlFile->float8ByVal != true)
4500 ereport(FATAL,
4501 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4502 errmsg("database files are incompatible with server"),
4503 errdetail("The database cluster was initialized without USE_FLOAT8_BYVAL"
4504 " but the server was compiled with USE_FLOAT8_BYVAL."),
4505 errhint("It looks like you need to recompile or initdb.")));
4506#else
4507 if (ControlFile->float8ByVal != false)
4508 ereport(FATAL,
4509 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4510 errmsg("database files are incompatible with server"),
4511 errdetail("The database cluster was initialized with USE_FLOAT8_BYVAL"
4512 " but the server was compiled without USE_FLOAT8_BYVAL."),
4513 errhint("It looks like you need to recompile or initdb.")));
4514#endif
4515
4517
4519 ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4520 errmsg_plural("invalid WAL segment size in control file (%d byte)",
4521 "invalid WAL segment size in control file (%d bytes)",
4524 errdetail("The WAL segment size must be a power of two between 1 MB and 1 GB.")));
4525
4526 snprintf(wal_segsz_str, sizeof(wal_segsz_str), "%d", wal_segment_size);
4527 SetConfigOption("wal_segment_size", wal_segsz_str, PGC_INTERNAL,
4529
4530 /* check and update variables dependent on wal_segment_size */
4532 ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4533 /* translator: both %s are GUC names */
4534 errmsg("\"%s\" must be at least twice \"%s\"",
4535 "min_wal_size", "wal_segment_size")));
4536
4538 ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4539 /* translator: both %s are GUC names */
4540 errmsg("\"%s\" must be at least twice \"%s\"",
4541 "max_wal_size", "wal_segment_size")));
4542
4544 (wal_segment_size / XLOG_BLCKSZ * UsableBytesInPage) -
4546
4548
4549 /* Make the initdb settings visible as GUC variables, too */
4550 SetConfigOption("data_checksums", DataChecksumsEnabled() ? "yes" : "no",
4552}
#define PG_BINARY
Definition: c.h:1227
#define CATALOG_VERSION_NO
Definition: catversion.h:60
int errmsg_plural(const char *fmt_singular, const char *fmt_plural, unsigned long n,...)
Definition: elog.c:1180
int BasicOpenFile(const char *fileName, int fileFlags)
Definition: fd.c:1086
void SetConfigOption(const char *name, const char *value, GucContext context, GucSource source)
Definition: guc.c:4332
@ PGC_S_DYNAMIC_DEFAULT
Definition: guc.h:110
@ PGC_INTERNAL
Definition: guc.h:69
#define TOAST_MAX_CHUNK_SIZE
Definition: heaptoast.h:84
#define read(a, b, c)
Definition: win32.h:13
#define LOBLKSIZE
Definition: large_object.h:70
#define INDEX_MAX_KEYS
#define NAMEDATALEN
#define FLOATFORMAT_VALUE
Definition: pg_control.h:201
#define PG_CONTROL_VERSION
Definition: pg_control.h:25
#define EQ_CRC32C(c1, c2)
Definition: pg_crc32c.h:42
uint32 pg_control_version
Definition: pg_control.h:125
uint32 xlog_seg_size
Definition: pg_control.h:211
uint32 nameDataLen
Definition: pg_control.h:213
uint32 indexMaxKeys
Definition: pg_control.h:214
uint32 relseg_size
Definition: pg_control.h:208
uint32 catalog_version_no
Definition: pg_control.h:126
double floatFormat
Definition: pg_control.h:200
uint32 xlog_blcksz
Definition: pg_control.h:210
uint32 loblksize
Definition: pg_control.h:217
pg_crc32c crc
Definition: pg_control.h:232
uint32 toast_max_chunk_size
Definition: pg_control.h:216
#define UsableBytesInPage
Definition: xlog.c:597
bool DataChecksumsEnabled(void)
Definition: xlog.c:4588
static int UsableBytesInSegment
Definition: xlog.c:606
int min_wal_size_mb
Definition: xlog.c:115
#define XLOG_CONTROL_FILE

References BasicOpenFile(), ControlFileData::blcksz, CalculateCheckpointSegments(), CATALOG_VERSION_NO, ControlFileData::catalog_version_no, close, COMP_CRC32C, ControlFile, ConvertToXSegs, ControlFileData::crc, crc, DataChecksumsEnabled(), EQ_CRC32C, ereport, errcode(), ERRCODE_DATA_CORRUPTED, errcode_for_file_access(), errdetail(), errhint(), errmsg(), errmsg_plural(), ERROR, FATAL, fd(), FIN_CRC32C, ControlFileData::float8ByVal, ControlFileData::floatFormat, FLOATFORMAT_VALUE, INDEX_MAX_KEYS, ControlFileData::indexMaxKeys, INIT_CRC32C, IsValidWalSegSize, ControlFileData::loblksize, LOBLKSIZE, max_wal_size_mb, ControlFileData::maxAlign, min_wal_size_mb, ControlFileData::nameDataLen, NAMEDATALEN, PANIC, PG_BINARY, PG_CONTROL_VERSION, ControlFileData::pg_control_version, PGC_INTERNAL, PGC_S_DYNAMIC_DEFAULT, pgstat_report_wait_end(), pgstat_report_wait_start(), read, ControlFileData::relseg_size, SetConfigOption(), SizeOfXLogLongPHD, SizeOfXLogShortPHD, snprintf, TOAST_MAX_CHUNK_SIZE, ControlFileData::toast_max_chunk_size, UsableBytesInPage, UsableBytesInSegment, wal_segment_size, ControlFileData::xlog_blcksz, XLOG_CONTROL_FILE, and ControlFileData::xlog_seg_size.

Referenced by BootStrapXLOG(), and LocalProcessControlFile().

◆ RecoveryInProgress()

bool RecoveryInProgress ( void  )

Definition at line 6334 of file xlog.c.

6335{
6336 /*
6337 * We check shared state each time only until we leave recovery mode. We
6338 * can't re-enter recovery, so there's no need to keep checking after the
6339 * shared variable has once been seen false.
6340 */
6342 return false;
6343 else
6344 {
6345 /*
6346 * use volatile pointer to make sure we make a fresh read of the
6347 * shared variable.
6348 */
6349 volatile XLogCtlData *xlogctl = XLogCtl;
6350
6352
6353 /*
6354 * Note: We don't need a memory barrier when we're still in recovery.
6355 * We might exit recovery immediately after return, so the caller
6356 * can't rely on 'true' meaning that we're still in recovery anyway.
6357 */
6358
6360 }
6361}
static bool LocalRecoveryInProgress
Definition: xlog.c:224

References LocalRecoveryInProgress, RECOVERY_STATE_DONE, XLogCtlData::SharedRecoveryState, and XLogCtl.

Referenced by attribute_statistics_update(), BackgroundWriterMain(), BeginReportingGUCOptions(), brin_desummarize_range(), brin_summarize_range(), btree_index_mainfork_expected(), check_transaction_isolation(), check_transaction_read_only(), CheckArchiveTimeout(), CheckLogicalDecodingRequirements(), CheckpointerMain(), ComputeXidHorizons(), CreateCheckPoint(), CreateDecodingContext(), CreateEndOfRecoveryRecord(), CreateOverwriteContrecordRecord(), CreateRestartPoint(), do_pg_backup_start(), do_pg_backup_stop(), error_commit_ts_disabled(), get_relation_info(), GetCurrentLSN(), GetLatestLSN(), GetNewMultiXactId(), GetNewObjectId(), GetNewTransactionId(), GetOldestActiveTransactionId(), GetOldestSafeDecodingTransactionId(), GetRunningTransactionData(), GetSerializableTransactionSnapshot(), GetSerializableTransactionSnapshotInt(), GetSnapshotData(), GetStrictOldestNonRemovableTransactionId(), gin_clean_pending_list(), GlobalVisHorizonKindForRel(), heap_force_common(), heap_page_prune_opt(), IdentifySystem(), InitTempTableNamespace(), IsCheckpointOnSchedule(), LockAcquireExtended(), logical_read_xlog_page(), MaintainLatestCompletedXid(), MarkBufferDirtyHint(), perform_base_backup(), pg_clear_attribute_stats(), pg_create_restore_point(), pg_current_wal_flush_lsn(), pg_current_wal_insert_lsn(), pg_current_wal_lsn(), pg_get_sequence_data(), pg_get_wal_replay_pause_state(), pg_is_in_recovery(), pg_is_wal_replay_paused(), pg_log_standby_snapshot(), pg_logical_slot_get_changes_guts(), pg_promote(), pg_replication_slot_advance(), pg_sequence_last_value(), pg_switch_wal(), pg_sync_replication_slots(), pg_wal_replay_pause(), pg_wal_replay_resume(), pg_walfile_name(), pg_walfile_name_offset(), PhysicalWakeupLogicalWalSnd(), PrepareRedoAdd(), PrepareRedoRemove(), PreventCommandDuringRecovery(), ProcSleep(), read_local_xlog_page_guts(), ReadReplicationSlot(), recovery_create_dbdir(), relation_statistics_update(), ReplicationSlotAlter(), ReplicationSlotCreate(), ReplicationSlotDrop(), ReplicationSlotReserveWal(), replorigin_check_prerequisites(), ReportChangedGUCOptions(), sendDir(), SerialSetActiveSerXmin(), show_in_hot_standby(), ShutdownXLOG(), SnapBuildWaitSnapshot(), standard_ProcessUtility(), StandbySlotsHaveCaughtup(), StartLogicalReplication(), StartReplication(), StartTransaction(), TransactionIdIsInProgress(), TruncateMultiXact(), UpdateFullPageWrites(), verify_heapam(), WALReadFromBuffers(), WalReceiverMain(), WalSndWaitForWal(), xlog_decode(), XLogBackgroundFlush(), XLogFlush(), XLogInsertAllowed(), XLogNeedsFlush(), and XLogSendPhysical().

◆ RecoveryRestartPoint()

static void RecoveryRestartPoint ( const CheckPoint checkPoint,
XLogReaderState record 
)
static

Definition at line 7550 of file xlog.c.

7551{
7552 /*
7553 * Also refrain from creating a restartpoint if we have seen any
7554 * references to non-existent pages. Restarting recovery from the
7555 * restartpoint would not see the references, so we would lose the
7556 * cross-check that the pages belonged to a relation that was dropped
7557 * later.
7558 */
7560 {
7561 elog(DEBUG2,
7562 "could not record restart point at %X/%X because there "
7563 "are unresolved references to invalid pages",
7564 LSN_FORMAT_ARGS(checkPoint->redo));
7565 return;
7566 }
7567
7568 /*
7569 * Copy the checkpoint record to shared memory, so that checkpointer can
7570 * work out the next time it wants to perform a restartpoint.
7571 */
7575 XLogCtl->lastCheckPoint = *checkPoint;
7577}
XLogRecPtr EndRecPtr
Definition: xlogreader.h:207
XLogRecPtr ReadRecPtr
Definition: xlogreader.h:206
bool XLogHaveInvalidPages(void)
Definition: xlogutils.c:235

References DEBUG2, elog, XLogReaderState::EndRecPtr, XLogCtlData::info_lck, XLogCtlData::lastCheckPoint, XLogCtlData::lastCheckPointEndPtr, XLogCtlData::lastCheckPointRecPtr, LSN_FORMAT_ARGS, XLogReaderState::ReadRecPtr, CheckPoint::redo, SpinLockAcquire, SpinLockRelease, XLogCtl, and XLogHaveInvalidPages().

Referenced by xlog_redo().

◆ register_persistent_abort_backup_handler()

void register_persistent_abort_backup_handler ( void  )

Definition at line 9421 of file xlog.c.

9422{
9423 static bool already_done = false;
9424
9425 if (already_done)
9426 return;
9428 already_done = true;
9429}
void before_shmem_exit(pg_on_exit_callback function, Datum arg)
Definition: ipc.c:337

References before_shmem_exit(), DatumGetBool(), and do_pg_abort_backup().

Referenced by pg_backup_start().

◆ RemoveNonParentXlogFiles()

void RemoveNonParentXlogFiles ( XLogRecPtr  switchpoint,
TimeLineID  newTLI 
)

Definition at line 3940 of file xlog.c.

3941{
3942 DIR *xldir;
3943 struct dirent *xlde;
3944 char switchseg[MAXFNAMELEN];
3945 XLogSegNo endLogSegNo;
3946 XLogSegNo switchLogSegNo;
3947 XLogSegNo recycleSegNo;
3948
3949 /*
3950 * Initialize info about where to begin the work. This will recycle,
3951 * somewhat arbitrarily, 10 future segments.
3952 */
3953 XLByteToPrevSeg(switchpoint, switchLogSegNo, wal_segment_size);
3954 XLByteToSeg(switchpoint, endLogSegNo, wal_segment_size);
3955 recycleSegNo = endLogSegNo + 10;
3956
3957 /*
3958 * Construct a filename of the last segment to be kept.
3959 */
3960 XLogFileName(switchseg, newTLI, switchLogSegNo, wal_segment_size);
3961
3962 elog(DEBUG2, "attempting to remove WAL segments newer than log file %s",
3963 switchseg);
3964
3965 xldir = AllocateDir(XLOGDIR);
3966
3967 while ((xlde = ReadDir(xldir, XLOGDIR)) != NULL)
3968 {
3969 /* Ignore files that are not XLOG segments */
3970 if (!IsXLogFileName(xlde->d_name))
3971 continue;
3972
3973 /*
3974 * Remove files that are on a timeline older than the new one we're
3975 * switching to, but with a segment number >= the first segment on the
3976 * new timeline.
3977 */
3978 if (strncmp(xlde->d_name, switchseg, 8) < 0 &&
3979 strcmp(xlde->d_name + 8, switchseg + 8) > 0)
3980 {
3981 /*
3982 * If the file has already been marked as .ready, however, don't
3983 * remove it yet. It should be OK to remove it - files that are
3984 * not part of our timeline history are not required for recovery
3985 * - but seems safer to let them be archived and removed later.
3986 */
3987 if (!XLogArchiveIsReady(xlde->d_name))
3988 RemoveXlogFile(xlde, recycleSegNo, &endLogSegNo, newTLI);
3989 }
3990 }
3991
3992 FreeDir(xldir);
3993}
static void RemoveXlogFile(const struct dirent *segment_de, XLogSegNo recycleSegNo, XLogSegNo *endlogSegNo, TimeLineID insertTLI)
Definition: xlog.c:4009
static bool IsXLogFileName(const char *fname)
bool XLogArchiveIsReady(const char *xlog)
Definition: xlogarchive.c:694

References AllocateDir(), dirent::d_name, DEBUG2, elog, FreeDir(), IsXLogFileName(), MAXFNAMELEN, ReadDir(), RemoveXlogFile(), wal_segment_size, XLByteToPrevSeg, XLByteToSeg, XLogArchiveIsReady(), XLOGDIR, and XLogFileName().

Referenced by ApplyWalRecord(), and CleanupAfterArchiveRecovery().

◆ RemoveOldXlogFiles()

static void RemoveOldXlogFiles ( XLogSegNo  segno,
XLogRecPtr  lastredoptr,
XLogRecPtr  endptr,
TimeLineID  insertTLI 
)
static

Definition at line 3865 of file xlog.c.

3867{
3868 DIR *xldir;
3869 struct dirent *xlde;
3870 char lastoff[MAXFNAMELEN];
3871 XLogSegNo endlogSegNo;
3872 XLogSegNo recycleSegNo;
3873
3874 /* Initialize info about where to try to recycle to */
3875 XLByteToSeg(endptr, endlogSegNo, wal_segment_size);
3876 recycleSegNo = XLOGfileslop(lastredoptr);
3877
3878 /*
3879 * Construct a filename of the last segment to be kept. The timeline ID
3880 * doesn't matter, we ignore that in the comparison. (During recovery,
3881 * InsertTimeLineID isn't set, so we can't use that.)
3882 */
3883 XLogFileName(lastoff, 0, segno, wal_segment_size);
3884
3885 elog(DEBUG2, "attempting to remove WAL segments older than log file %s",
3886 lastoff);
3887
3888 xldir = AllocateDir(XLOGDIR);
3889
3890 while ((xlde = ReadDir(xldir, XLOGDIR)) != NULL)
3891 {
3892 /* Ignore files that are not XLOG segments */
3893 if (!IsXLogFileName(xlde->d_name) &&
3895 continue;
3896
3897 /*
3898 * We ignore the timeline part of the XLOG segment identifiers in
3899 * deciding whether a segment is still needed. This ensures that we
3900 * won't prematurely remove a segment from a parent timeline. We could
3901 * probably be a little more proactive about removing segments of
3902 * non-parent timelines, but that would be a whole lot more
3903 * complicated.
3904 *
3905 * We use the alphanumeric sorting property of the filenames to decide
3906 * which ones are earlier than the lastoff segment.
3907 */
3908 if (strcmp(xlde->d_name + 8, lastoff + 8) <= 0)
3909 {
3910 if (XLogArchiveCheckDone(xlde->d_name))
3911 {
3912 /* Update the last removed location in shared memory first */
3914
3915 RemoveXlogFile(xlde, recycleSegNo, &endlogSegNo, insertTLI);
3916 }
3917 }
3918 }
3919
3920 FreeDir(xldir);
3921}
static XLogSegNo XLOGfileslop(XLogRecPtr lastredoptr)
Definition: xlog.c:2240
static void UpdateLastRemovedPtr(char *filename)
Definition: xlog.c:3812
static bool IsPartialXLogFileName(const char *fname)

References AllocateDir(), dirent::d_name, DEBUG2, elog, FreeDir(), IsPartialXLogFileName(), IsXLogFileName(), MAXFNAMELEN, ReadDir(), RemoveXlogFile(), UpdateLastRemovedPtr(), wal_segment_size, XLByteToSeg, XLogArchiveCheckDone(), XLOGDIR, XLogFileName(), and XLOGfileslop().

Referenced by CreateCheckPoint(), and CreateRestartPoint().

◆ RemoveTempXlogFiles()

static void RemoveTempXlogFiles ( void  )
static

Definition at line 3832 of file xlog.c.

3833{
3834 DIR *xldir;
3835 struct dirent *xlde;
3836
3837 elog(DEBUG2, "removing all temporary WAL segments");
3838
3839 xldir = AllocateDir(XLOGDIR);
3840 while ((xlde = ReadDir(xldir, XLOGDIR)) != NULL)
3841 {
3842 char path[MAXPGPATH];
3843
3844 if (strncmp(xlde->d_name, "xlogtemp.", 9) != 0)
3845 continue;
3846
3847 snprintf(path, MAXPGPATH, XLOGDIR "/%s", xlde->d_name);
3848 unlink(path);
3849 elog(DEBUG2, "removed temporary WAL segment \"%s\"", path);
3850 }
3851 FreeDir(xldir);
3852}

References AllocateDir(), dirent::d_name, DEBUG2, elog, FreeDir(), MAXPGPATH, ReadDir(), snprintf, and XLOGDIR.

Referenced by StartupXLOG().

◆ RemoveXlogFile()

static void RemoveXlogFile ( const struct dirent segment_de,
XLogSegNo  recycleSegNo,
XLogSegNo endlogSegNo,
TimeLineID  insertTLI 
)
static

Definition at line 4009 of file xlog.c.

4012{
4013 char path[MAXPGPATH];
4014#ifdef WIN32
4015 char newpath[MAXPGPATH];
4016#endif
4017 const char *segname = segment_de->d_name;
4018
4019 snprintf(path, MAXPGPATH, XLOGDIR "/%s", segname);
4020
4021 /*
4022 * Before deleting the file, see if it can be recycled as a future log
4023 * segment. Only recycle normal files, because we don't want to recycle
4024 * symbolic links pointing to a separate archive directory.
4025 */
4026 if (wal_recycle &&
4027 *endlogSegNo <= recycleSegNo &&
4028 XLogCtl->InstallXLogFileSegmentActive && /* callee rechecks this */
4029 get_dirent_type(path, segment_de, false, DEBUG2) == PGFILETYPE_REG &&
4030 InstallXLogFileSegment(endlogSegNo, path,
4031 true, recycleSegNo, insertTLI))
4032 {
4034 (errmsg_internal("recycled write-ahead log file \"%s\"",
4035 segname)));
4037 /* Needn't recheck that slot on future iterations */
4038 (*endlogSegNo)++;
4039 }
4040 else
4041 {
4042 /* No need for any more future segments, or recycling failed ... */
4043 int rc;
4044
4046 (errmsg_internal("removing write-ahead log file \"%s\"",
4047 segname)));
4048
4049#ifdef WIN32
4050
4051 /*
4052 * On Windows, if another process (e.g another backend) holds the file
4053 * open in FILE_SHARE_DELETE mode, unlink will succeed, but the file
4054 * will still show up in directory listing until the last handle is
4055 * closed. To avoid confusing the lingering deleted file for a live
4056 * WAL file that needs to be archived, rename it before deleting it.
4057 *
4058 * If another process holds the file open without FILE_SHARE_DELETE
4059 * flag, rename will fail. We'll try again at the next checkpoint.
4060 */
4061 snprintf(newpath, MAXPGPATH, "%s.deleted", path);
4062 if (rename(path, newpath) != 0)
4063 {
4064 ereport(LOG,
4066 errmsg("could not rename file \"%s\": %m",
4067 path)));
4068 return;
4069 }
4070 rc = durable_unlink(newpath, LOG);
4071#else
4072 rc = durable_unlink(path, LOG);
4073#endif
4074 if (rc != 0)
4075 {
4076 /* Message already logged by durable_unlink() */
4077 return;
4078 }
4080 }
4081
4082 XLogArchiveCleanup(segname);
4083}
@ PGFILETYPE_REG
Definition: file_utils.h:22
static bool InstallXLogFileSegment(XLogSegNo *segno, char *tmppath, bool find_free, XLogSegNo max_segno, TimeLineID tli)
Definition: xlog.c:3563
bool wal_recycle
Definition: xlog.c:128

References CheckpointStats, CheckpointStatsData::ckpt_segs_recycled, CheckpointStatsData::ckpt_segs_removed, dirent::d_name, DEBUG2, durable_unlink(), ereport, errcode_for_file_access(), errmsg(), errmsg_internal(), get_dirent_type(), InstallXLogFileSegment(), XLogCtlData::InstallXLogFileSegmentActive, LOG, MAXPGPATH, PGFILETYPE_REG, snprintf, wal_recycle, XLogArchiveCleanup(), XLogCtl, and XLOGDIR.

Referenced by RemoveNonParentXlogFiles(), and RemoveOldXlogFiles().

◆ RequestXLogSwitch()

XLogRecPtr RequestXLogSwitch ( bool  mark_unimportant)

Definition at line 8060 of file xlog.c.

8061{
8062 XLogRecPtr RecPtr;
8063
8064 /* XLOG SWITCH has no data */
8066
8067 if (mark_unimportant)
8069 RecPtr = XLogInsert(RM_XLOG_ID, XLOG_SWITCH);
8070
8071 return RecPtr;
8072}
#define XLOG_SWITCH
Definition: pg_control.h:72
#define XLOG_MARK_UNIMPORTANT
Definition: xlog.h:155
void XLogSetRecordFlags(uint8 flags)
Definition: xloginsert.c:456

References XLOG_MARK_UNIMPORTANT, XLOG_SWITCH, XLogBeginInsert(), XLogInsert(), and XLogSetRecordFlags().

Referenced by CheckArchiveTimeout(), do_pg_backup_start(), do_pg_backup_stop(), pg_switch_wal(), and ShutdownXLOG().

◆ ReserveXLogInsertLocation()

static pg_attribute_always_inline void ReserveXLogInsertLocation ( int  size,
XLogRecPtr StartPos,
XLogRecPtr EndPos,
XLogRecPtr PrevPtr 
)
static

Definition at line 1108 of file xlog.c.

1110{
1112 uint64 startbytepos;
1113 uint64 endbytepos;
1114 uint64 prevbytepos;
1115
1116 size = MAXALIGN(size);
1117
1118 /* All (non xlog-switch) records should contain data. */
1120
1121 /*
1122 * The duration the spinlock needs to be held is minimized by minimizing
1123 * the calculations that have to be done while holding the lock. The
1124 * current tip of reserved WAL is kept in CurrBytePos, as a byte position
1125 * that only counts "usable" bytes in WAL, that is, it excludes all WAL
1126 * page headers. The mapping between "usable" byte positions and physical
1127 * positions (XLogRecPtrs) can be done outside the locked region, and
1128 * because the usable byte position doesn't include any headers, reserving
1129 * X bytes from WAL is almost as simple as "CurrBytePos += X".
1130 */
1131 SpinLockAcquire(&Insert->insertpos_lck);
1132
1133 startbytepos = Insert->CurrBytePos;
1134 endbytepos = startbytepos + size;
1135 prevbytepos = Insert->PrevBytePos;
1136 Insert->CurrBytePos = endbytepos;
1137 Insert->PrevBytePos = startbytepos;
1138
1139 SpinLockRelease(&Insert->insertpos_lck);
1140
1141 *StartPos = XLogBytePosToRecPtr(startbytepos);
1142 *EndPos = XLogBytePosToEndRecPtr(endbytepos);
1143 *PrevPtr = XLogBytePosToRecPtr(prevbytepos);
1144
1145 /*
1146 * Check that the conversions between "usable byte positions" and
1147 * XLogRecPtrs work consistently in both directions.
1148 */
1149 Assert(XLogRecPtrToBytePos(*StartPos) == startbytepos);
1150 Assert(XLogRecPtrToBytePos(*EndPos) == endbytepos);
1151 Assert(XLogRecPtrToBytePos(*PrevPtr) == prevbytepos);
1152}
#define MAXALIGN(LEN)
Definition: c.h:765
static pg_noinline void Size size
Definition: slab.c:607
static XLogRecPtr XLogBytePosToEndRecPtr(uint64 bytepos)
Definition: xlog.c:1898
static uint64 XLogRecPtrToBytePos(XLogRecPtr ptr)
Definition: xlog.c:1941

References Assert, XLogCtlData::Insert, Insert(), MAXALIGN, size, SizeOfXLogRecord, SpinLockAcquire, SpinLockRelease, XLogBytePosToEndRecPtr(), XLogBytePosToRecPtr(), XLogCtl, and XLogRecPtrToBytePos().

Referenced by XLogInsertRecord().

◆ ReserveXLogSwitch()

static bool ReserveXLogSwitch ( XLogRecPtr StartPos,
XLogRecPtr EndPos,
XLogRecPtr PrevPtr 
)
static

Definition at line 1164 of file xlog.c.

1165{
1167 uint64 startbytepos;
1168 uint64 endbytepos;
1169 uint64 prevbytepos;
1171 XLogRecPtr ptr;
1172 uint32 segleft;
1173
1174 /*
1175 * These calculations are a bit heavy-weight to be done while holding a
1176 * spinlock, but since we're holding all the WAL insertion locks, there
1177 * are no other inserters competing for it. GetXLogInsertRecPtr() does
1178 * compete for it, but that's not called very frequently.
1179 */
1180 SpinLockAcquire(&Insert->insertpos_lck);
1181
1182 startbytepos = Insert->CurrBytePos;
1183
1184 ptr = XLogBytePosToEndRecPtr(startbytepos);
1185 if (XLogSegmentOffset(ptr, wal_segment_size) == 0)
1186 {
1187 SpinLockRelease(&Insert->insertpos_lck);
1188 *EndPos = *StartPos = ptr;
1189 return false;
1190 }
1191
1192 endbytepos = startbytepos + size;
1193 prevbytepos = Insert->PrevBytePos;
1194
1195 *StartPos = XLogBytePosToRecPtr(startbytepos);
1196 *EndPos = XLogBytePosToEndRecPtr(endbytepos);
1197
1199 if (segleft != wal_segment_size)
1200 {
1201 /* consume the rest of the segment */
1202 *EndPos += segleft;
1203 endbytepos = XLogRecPtrToBytePos(*EndPos);
1204 }
1205 Insert->CurrBytePos = endbytepos;
1206 Insert->PrevBytePos = startbytepos;
1207
1208 SpinLockRelease(&Insert->insertpos_lck);
1209
1210 *PrevPtr = XLogBytePosToRecPtr(prevbytepos);
1211
1213 Assert(XLogRecPtrToBytePos(*EndPos) == endbytepos);
1214 Assert(XLogRecPtrToBytePos(*StartPos) == startbytepos);
1215 Assert(XLogRecPtrToBytePos(*PrevPtr) == prevbytepos);
1216
1217 return true;
1218}

References Assert, XLogCtlData::Insert, Insert(), MAXALIGN, size, SizeOfXLogRecord, SpinLockAcquire, SpinLockRelease, wal_segment_size, XLogBytePosToEndRecPtr(), XLogBytePosToRecPtr(), XLogCtl, XLogRecPtrToBytePos(), and XLogSegmentOffset.

Referenced by XLogInsertRecord().

◆ SetInstallXLogFileSegmentActive()

void SetInstallXLogFileSegmentActive ( void  )

Definition at line 9484 of file xlog.c.

9485{
9486 LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
9488 LWLockRelease(ControlFileLock);
9489}

References XLogCtlData::InstallXLogFileSegmentActive, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), and XLogCtl.

Referenced by BootStrapXLOG(), StartupXLOG(), and WaitForWALToBecomeAvailable().

◆ SetWalWriterSleeping()

void SetWalWriterSleeping ( bool  sleeping)

Definition at line 9507 of file xlog.c.

9508{
9510 XLogCtl->WalWriterSleeping = sleeping;
9512}
bool WalWriterSleeping
Definition: xlog.c:533

References XLogCtlData::info_lck, SpinLockAcquire, SpinLockRelease, XLogCtlData::WalWriterSleeping, and XLogCtl.

Referenced by WalWriterMain().

◆ show_archive_command()

const char * show_archive_command ( void  )

Definition at line 4810 of file xlog.c.

4811{
4812 if (XLogArchivingActive())
4813 return XLogArchiveCommand;
4814 else
4815 return "(disabled)";
4816}
char * XLogArchiveCommand
Definition: xlog.c:120

References XLogArchiveCommand, and XLogArchivingActive.

◆ show_in_hot_standby()

const char * show_in_hot_standby ( void  )

Definition at line 4822 of file xlog.c.

4823{
4824 /*
4825 * We display the actual state based on shared memory, so that this GUC
4826 * reports up-to-date state if examined intra-query. The underlying
4827 * variable (in_hot_standby_guc) changes only when we transmit a new value
4828 * to the client.
4829 */
4830 return RecoveryInProgress() ? "on" : "off";
4831}

References RecoveryInProgress().

◆ ShutdownXLOG()

void ShutdownXLOG ( int  code,
Datum  arg 
)

Definition at line 6602 of file xlog.c.

6603{
6604 /*
6605 * We should have an aux process resource owner to use, and we should not
6606 * be in a transaction that's installed some other resowner.
6607 */
6609 Assert(CurrentResourceOwner == NULL ||
6612
6613 /* Don't be chatty in standalone mode */
6615 (errmsg("shutting down")));
6616
6617 /*
6618 * Signal walsenders to move to stopping state.
6619 */
6621
6622 /*
6623 * Wait for WAL senders to be in stopping state. This prevents commands
6624 * from writing new WAL.
6625 */
6627
6628 if (RecoveryInProgress())
6630 else
6631 {
6632 /*
6633 * If archiving is enabled, rotate the last XLOG file so that all the
6634 * remaining records are archived (postmaster wakes up the archiver
6635 * process one more time at the end of shutdown). The checkpoint
6636 * record will go to the next XLOG file and won't be archived (yet).
6637 */
6638 if (XLogArchivingActive())
6639 RequestXLogSwitch(false);
6640
6642 }
6643}
bool IsPostmasterEnvironment
Definition: globals.c:118
ResourceOwner CurrentResourceOwner
Definition: resowner.c:165
ResourceOwner AuxProcessResourceOwner
Definition: resowner.c:168
void WalSndInitStopping(void)
Definition: walsender.c:3718
void WalSndWaitStopping(void)
Definition: walsender.c:3744
bool CreateRestartPoint(int flags)
Definition: xlog.c:7591
bool CreateCheckPoint(int flags)
Definition: xlog.c:6889

References Assert, AuxProcessResourceOwner, CHECKPOINT_IMMEDIATE, CHECKPOINT_IS_SHUTDOWN, CreateCheckPoint(), CreateRestartPoint(), CurrentResourceOwner, ereport, errmsg(), IsPostmasterEnvironment, LOG, NOTICE, RecoveryInProgress(), RequestXLogSwitch(), WalSndInitStopping(), WalSndWaitStopping(), and XLogArchivingActive.

Referenced by HandleCheckpointerInterrupts(), and InitPostgres().

◆ StartupXLOG()

void StartupXLOG ( void  )

Definition at line 5429 of file xlog.c.

5430{
5432 CheckPoint checkPoint;
5433 bool wasShutdown;
5434 bool didCrash;
5435 bool haveTblspcMap;
5436 bool haveBackupLabel;
5437 XLogRecPtr EndOfLog;
5438 TimeLineID EndOfLogTLI;
5439 TimeLineID newTLI;
5440 bool performedWalRecovery;
5441 EndOfWalRecoveryInfo *endOfRecoveryInfo;
5444 TransactionId oldestActiveXID;
5445 bool promoted = false;
5446
5447 /*
5448 * We should have an aux process resource owner to use, and we should not
5449 * be in a transaction that's installed some other resowner.
5450 */
5452 Assert(CurrentResourceOwner == NULL ||
5455
5456 /*
5457 * Check that contents look valid.
5458 */
5460 ereport(FATAL,
5462 errmsg("control file contains invalid checkpoint location")));
5463
5464 switch (ControlFile->state)
5465 {
5466 case DB_SHUTDOWNED:
5467
5468 /*
5469 * This is the expected case, so don't be chatty in standalone
5470 * mode
5471 */
5473 (errmsg("database system was shut down at %s",
5475 break;
5476
5478 ereport(LOG,
5479 (errmsg("database system was shut down in recovery at %s",
5481 break;
5482
5483 case DB_SHUTDOWNING:
5484 ereport(LOG,
5485 (errmsg("database system shutdown was interrupted; last known up at %s",
5487 break;
5488
5490 ereport(LOG,
5491 (errmsg("database system was interrupted while in recovery at %s",
5493 errhint("This probably means that some data is corrupted and"
5494 " you will have to use the last backup for recovery.")));
5495 break;
5496
5498 ereport(LOG,
5499 (errmsg("database system was interrupted while in recovery at log time %s",
5501 errhint("If this has occurred more than once some data might be corrupted"
5502 " and you might need to choose an earlier recovery target.")));
5503 break;
5504
5505 case DB_IN_PRODUCTION:
5506 ereport(LOG,
5507 (errmsg("database system was interrupted; last known up at %s",
5509 break;
5510
5511 default:
5512 ereport(FATAL,
5514 errmsg("control file contains invalid database cluster state")));
5515 }
5516
5517 /* This is just to allow attaching to startup process with a debugger */
5518#ifdef XLOG_REPLAY_DELAY
5520 pg_usleep(60000000L);
5521#endif
5522
5523 /*
5524 * Verify that pg_wal, pg_wal/archive_status, and pg_wal/summaries exist.
5525 * In cases where someone has performed a copy for PITR, these directories
5526 * may have been excluded and need to be re-created.
5527 */
5529
5530 /* Set up timeout handler needed to report startup progress. */
5534
5535 /*----------
5536 * If we previously crashed, perform a couple of actions:
5537 *
5538 * - The pg_wal directory may still include some temporary WAL segments
5539 * used when creating a new segment, so perform some clean up to not
5540 * bloat this path. This is done first as there is no point to sync
5541 * this temporary data.
5542 *
5543 * - There might be data which we had written, intending to fsync it, but
5544 * which we had not actually fsync'd yet. Therefore, a power failure in
5545 * the near future might cause earlier unflushed writes to be lost, even
5546 * though more recent data written to disk from here on would be
5547 * persisted. To avoid that, fsync the entire data directory.
5548 */
5551 {
5554 didCrash = true;
5555 }
5556 else
5557 didCrash = false;
5558
5559 /*
5560 * Prepare for WAL recovery if needed.
5561 *
5562 * InitWalRecovery analyzes the control file and the backup label file, if
5563 * any. It updates the in-memory ControlFile buffer according to the
5564 * starting checkpoint, and sets InRecovery and ArchiveRecoveryRequested.
5565 * It also applies the tablespace map file, if any.
5566 */
5567 InitWalRecovery(ControlFile, &wasShutdown,
5568 &haveBackupLabel, &haveTblspcMap);
5569 checkPoint = ControlFile->checkPointCopy;
5570
5571 /* initialize shared memory variables from the checkpoint record */
5572 TransamVariables->nextXid = checkPoint.nextXid;
5573 TransamVariables->nextOid = checkPoint.nextOid;
5575 MultiXactSetNextMXact(checkPoint.nextMulti, checkPoint.nextMultiOffset);
5576 AdvanceOldestClogXid(checkPoint.oldestXid);
5577 SetTransactionIdLimit(checkPoint.oldestXid, checkPoint.oldestXidDB);
5578 SetMultiXactIdLimit(checkPoint.oldestMulti, checkPoint.oldestMultiDB, true);
5580 checkPoint.newestCommitTsXid);
5581 XLogCtl->ckptFullXid = checkPoint.nextXid;
5582
5583 /*
5584 * Clear out any old relcache cache files. This is *necessary* if we do
5585 * any WAL replay, since that would probably result in the cache files
5586 * being out of sync with database reality. In theory we could leave them
5587 * in place if the database had been cleanly shut down, but it seems
5588 * safest to just remove them always and let them be rebuilt during the
5589 * first backend startup. These files needs to be removed from all
5590 * directories including pg_tblspc, however the symlinks are created only
5591 * after reading tablespace_map file in case of archive recovery from
5592 * backup, so needs to clear old relcache files here after creating
5593 * symlinks.
5594 */
5596
5597 /*
5598 * Initialize replication slots, before there's a chance to remove
5599 * required resources.
5600 */
5602
5603 /*
5604 * Startup logical state, needs to be setup now so we have proper data
5605 * during crash recovery.
5606 */
5608
5609 /*
5610 * Startup CLOG. This must be done after TransamVariables->nextXid has
5611 * been initialized and before we accept connections or begin WAL replay.
5612 */
5613 StartupCLOG();
5614
5615 /*
5616 * Startup MultiXact. We need to do this early to be able to replay
5617 * truncations.
5618 */
5620
5621 /*
5622 * Ditto for commit timestamps. Activate the facility if the setting is
5623 * enabled in the control file, as there should be no tracking of commit
5624 * timestamps done when the setting was disabled. This facility can be
5625 * started or stopped when replaying a XLOG_PARAMETER_CHANGE record.
5626 */
5629
5630 /*
5631 * Recover knowledge about replay progress of known replication partners.
5632 */
5634
5635 /*
5636 * Initialize unlogged LSN. On a clean shutdown, it's restored from the
5637 * control file. On recovery, all unlogged relations are blown away, so
5638 * the unlogged LSN counter can be reset too.
5639 */
5643 else
5646
5647 /*
5648 * Copy any missing timeline history files between 'now' and the recovery
5649 * target timeline from archive to pg_wal. While we don't need those files
5650 * ourselves - the history file of the recovery target timeline covers all
5651 * the previous timelines in the history too - a cascading standby server
5652 * might be interested in them. Or, if you archive the WAL from this
5653 * server to a different archive than the primary, it'd be good for all
5654 * the history files to get archived there after failover, so that you can
5655 * use one of the old timelines as a PITR target. Timeline history files
5656 * are small, so it's better to copy them unnecessarily than not copy them
5657 * and regret later.
5658 */
5660
5661 /*
5662 * Before running in recovery, scan pg_twophase and fill in its status to
5663 * be able to work on entries generated by redo. Doing a scan before
5664 * taking any recovery action has the merit to discard any 2PC files that
5665 * are newer than the first record to replay, saving from any conflicts at
5666 * replay. This avoids as well any subsequent scans when doing recovery
5667 * of the on-disk two-phase data.
5668 */
5670
5671 /*
5672 * When starting with crash recovery, reset pgstat data - it might not be
5673 * valid. Otherwise restore pgstat data. It's safe to do this here,
5674 * because postmaster will not yet have started any other processes.
5675 *
5676 * NB: Restoring replication slot stats relies on slot state to have
5677 * already been restored from disk.
5678 *
5679 * TODO: With a bit of extra work we could just start with a pgstat file
5680 * associated with the checkpoint redo location we're starting from.
5681 */
5682 if (didCrash)
5684 else
5685 pgstat_restore_stats(checkPoint.redo);
5686
5688
5691
5692 /* REDO */
5693 if (InRecovery)
5694 {
5695 /* Initialize state for RecoveryInProgress() */
5699 else
5702
5703 /*
5704 * Update pg_control to show that we are recovering and to show the
5705 * selected checkpoint as the place we are starting from. We also mark
5706 * pg_control with any minimum recovery stop point obtained from a
5707 * backup history file.
5708 *
5709 * No need to hold ControlFileLock yet, we aren't up far enough.
5710 */
5712
5713 /*
5714 * If there was a backup label file, it's done its job and the info
5715 * has now been propagated into pg_control. We must get rid of the
5716 * label file so that if we crash during recovery, we'll pick up at
5717 * the latest recovery restartpoint instead of going all the way back
5718 * to the backup start point. It seems prudent though to just rename
5719 * the file out of the way rather than delete it completely.
5720 */
5721 if (haveBackupLabel)
5722 {
5723 unlink(BACKUP_LABEL_OLD);
5725 }
5726
5727 /*
5728 * If there was a tablespace_map file, it's done its job and the
5729 * symlinks have been created. We must get rid of the map file so
5730 * that if we crash during recovery, we don't create symlinks again.
5731 * It seems prudent though to just rename the file out of the way
5732 * rather than delete it completely.
5733 */
5734 if (haveTblspcMap)
5735 {
5736 unlink(TABLESPACE_MAP_OLD);
5738 }
5739
5740 /*
5741 * Initialize our local copy of minRecoveryPoint. When doing crash
5742 * recovery we want to replay up to the end of WAL. Particularly, in
5743 * the case of a promoted standby minRecoveryPoint value in the
5744 * control file is only updated after the first checkpoint. However,
5745 * if the instance crashes before the first post-recovery checkpoint
5746 * is completed then recovery will use a stale location causing the
5747 * startup process to think that there are still invalid page
5748 * references when checking for data consistency.
5749 */
5751 {
5754 }
5755 else
5756 {
5759 }
5760
5761 /* Check that the GUCs used to generate the WAL allow recovery */
5763
5764 /*
5765 * We're in recovery, so unlogged relations may be trashed and must be
5766 * reset. This should be done BEFORE allowing Hot Standby
5767 * connections, so that read-only backends don't try to read whatever
5768 * garbage is left over from before.
5769 */
5771
5772 /*
5773 * Likewise, delete any saved transaction snapshot files that got left
5774 * behind by crashed backends.
5775 */
5777
5778 /*
5779 * Initialize for Hot Standby, if enabled. We won't let backends in
5780 * yet, not until we've reached the min recovery point specified in
5781 * control file and we've established a recovery snapshot from a
5782 * running-xacts WAL record.
5783 */
5785 {
5786 TransactionId *xids;
5787 int nxids;
5788
5790 (errmsg_internal("initializing for hot standby")));
5791
5793
5794 if (wasShutdown)
5795 oldestActiveXID = PrescanPreparedTransactions(&xids, &nxids);
5796 else
5797 oldestActiveXID = checkPoint.oldestActiveXid;
5798 Assert(TransactionIdIsValid(oldestActiveXID));
5799
5800 /* Tell procarray about the range of xids it has to deal with */
5802
5803 /*
5804 * Startup subtrans only. CLOG, MultiXact and commit timestamp
5805 * have already been started up and other SLRUs are not maintained
5806 * during recovery and need not be started yet.
5807 */
5808 StartupSUBTRANS(oldestActiveXID);
5809
5810 /*
5811 * If we're beginning at a shutdown checkpoint, we know that
5812 * nothing was running on the primary at this point. So fake-up an
5813 * empty running-xacts record and use that here and now. Recover
5814 * additional standby state for prepared transactions.
5815 */
5816 if (wasShutdown)
5817 {
5819 TransactionId latestCompletedXid;
5820
5821 /* Update pg_subtrans entries for any prepared transactions */
5823
5824 /*
5825 * Construct a RunningTransactions snapshot representing a
5826 * shut down server, with only prepared transactions still
5827 * alive. We're never overflowed at this point because all
5828 * subxids are listed with their parent prepared transactions.
5829 */
5830 running.xcnt = nxids;
5831 running.subxcnt = 0;
5833 running.nextXid = XidFromFullTransactionId(checkPoint.nextXid);
5834 running.oldestRunningXid = oldestActiveXID;
5835 latestCompletedXid = XidFromFullTransactionId(checkPoint.nextXid);
5836 TransactionIdRetreat(latestCompletedXid);
5837 Assert(TransactionIdIsNormal(latestCompletedXid));
5838 running.latestCompletedXid = latestCompletedXid;
5839 running.xids = xids;
5840
5842 }
5843 }
5844
5845 /*
5846 * We're all set for replaying the WAL now. Do it.
5847 */
5849 performedWalRecovery = true;
5850 }
5851 else
5852 performedWalRecovery = false;
5853
5854 /*
5855 * Finish WAL recovery.
5856 */
5857 endOfRecoveryInfo = FinishWalRecovery();
5858 EndOfLog = endOfRecoveryInfo->endOfLog;
5859 EndOfLogTLI = endOfRecoveryInfo->endOfLogTLI;
5860 abortedRecPtr = endOfRecoveryInfo->abortedRecPtr;
5861 missingContrecPtr = endOfRecoveryInfo->missingContrecPtr;
5862
5863 /*
5864 * Reset ps status display, so as no information related to recovery shows
5865 * up.
5866 */
5867 set_ps_display("");
5868
5869 /*
5870 * When recovering from a backup (we are in recovery, and archive recovery
5871 * was requested), complain if we did not roll forward far enough to reach
5872 * the point where the database is consistent. For regular online
5873 * backup-from-primary, that means reaching the end-of-backup WAL record
5874 * (at which point we reset backupStartPoint to be Invalid), for
5875 * backup-from-replica (which can't inject records into the WAL stream),
5876 * that point is when we reach the minRecoveryPoint in pg_control (which
5877 * we purposefully copy last when backing up from a replica). For
5878 * pg_rewind (which creates a backup_label with a method of "pg_rewind")
5879 * or snapshot-style backups (which don't), backupEndRequired will be set
5880 * to false.
5881 *
5882 * Note: it is indeed okay to look at the local variable
5883 * LocalMinRecoveryPoint here, even though ControlFile->minRecoveryPoint
5884 * might be further ahead --- ControlFile->minRecoveryPoint cannot have
5885 * been advanced beyond the WAL we processed.
5886 */
5887 if (InRecovery &&
5888 (EndOfLog < LocalMinRecoveryPoint ||
5890 {
5891 /*
5892 * Ran off end of WAL before reaching end-of-backup WAL record, or
5893 * minRecoveryPoint. That's a bad sign, indicating that you tried to
5894 * recover from an online backup but never called pg_backup_stop(), or
5895 * you didn't archive all the WAL needed.
5896 */
5898 {
5900 ereport(FATAL,
5901 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
5902 errmsg("WAL ends before end of online backup"),
5903 errhint("All WAL generated while online backup was taken must be available at recovery.")));
5904 else
5905 ereport(FATAL,
5906 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
5907 errmsg("WAL ends before consistent recovery point")));
5908 }
5909 }
5910
5911 /*
5912 * Reset unlogged relations to the contents of their INIT fork. This is
5913 * done AFTER recovery is complete so as to include any unlogged relations
5914 * created during recovery, but BEFORE recovery is marked as having
5915 * completed successfully. Otherwise we'd not retry if any of the post
5916 * end-of-recovery steps fail.
5917 */
5918 if (InRecovery)
5920
5921 /*
5922 * Pre-scan prepared transactions to find out the range of XIDs present.
5923 * This information is not quite needed yet, but it is positioned here so
5924 * as potential problems are detected before any on-disk change is done.
5925 */
5926 oldestActiveXID = PrescanPreparedTransactions(NULL, NULL);
5927
5928 /*
5929 * Allow ordinary WAL segment creation before possibly switching to a new
5930 * timeline, which creates a new segment, and after the last ReadRecord().
5931 */
5933
5934 /*
5935 * Consider whether we need to assign a new timeline ID.
5936 *
5937 * If we did archive recovery, we always assign a new ID. This handles a
5938 * couple of issues. If we stopped short of the end of WAL during
5939 * recovery, then we are clearly generating a new timeline and must assign
5940 * it a unique new ID. Even if we ran to the end, modifying the current
5941 * last segment is problematic because it may result in trying to
5942 * overwrite an already-archived copy of that segment, and we encourage
5943 * DBAs to make their archive_commands reject that. We can dodge the
5944 * problem by making the new active segment have a new timeline ID.
5945 *
5946 * In a normal crash recovery, we can just extend the timeline we were in.
5947 */
5948 newTLI = endOfRecoveryInfo->lastRecTLI;
5950 {
5952 ereport(LOG,
5953 (errmsg("selected new timeline ID: %u", newTLI)));
5954
5955 /*
5956 * Make a writable copy of the last WAL segment. (Note that we also
5957 * have a copy of the last block of the old WAL in
5958 * endOfRecovery->lastPage; we will use that below.)
5959 */
5960 XLogInitNewTimeline(EndOfLogTLI, EndOfLog, newTLI);
5961
5962 /*
5963 * Remove the signal files out of the way, so that we don't
5964 * accidentally re-enter archive recovery mode in a subsequent crash.
5965 */
5966 if (endOfRecoveryInfo->standby_signal_file_found)
5968
5969 if (endOfRecoveryInfo->recovery_signal_file_found)
5971
5972 /*
5973 * Write the timeline history file, and have it archived. After this
5974 * point (or rather, as soon as the file is archived), the timeline
5975 * will appear as "taken" in the WAL archive and to any standby
5976 * servers. If we crash before actually switching to the new
5977 * timeline, standby servers will nevertheless think that we switched
5978 * to the new timeline, and will try to connect to the new timeline.
5979 * To minimize the window for that, try to do as little as possible
5980 * between here and writing the end-of-recovery record.
5981 */
5983 EndOfLog, endOfRecoveryInfo->recoveryStopReason);
5984
5985 ereport(LOG,
5986 (errmsg("archive recovery complete")));
5987 }
5988
5989 /* Save the selected TimeLineID in shared memory, too */
5991 XLogCtl->InsertTimeLineID = newTLI;
5992 XLogCtl->PrevTimeLineID = endOfRecoveryInfo->lastRecTLI;
5994
5995 /*
5996 * Actually, if WAL ended in an incomplete record, skip the parts that
5997 * made it through and start writing after the portion that persisted.
5998 * (It's critical to first write an OVERWRITE_CONTRECORD message, which
5999 * we'll do as soon as we're open for writing new WAL.)
6000 */
6002 {
6003 /*
6004 * We should only have a missingContrecPtr if we're not switching to a
6005 * new timeline. When a timeline switch occurs, WAL is copied from the
6006 * old timeline to the new only up to the end of the last complete
6007 * record, so there can't be an incomplete WAL record that we need to
6008 * disregard.
6009 */
6010 Assert(newTLI == endOfRecoveryInfo->lastRecTLI);
6012 EndOfLog = missingContrecPtr;
6013 }
6014
6015 /*
6016 * Prepare to write WAL starting at EndOfLog location, and init xlog
6017 * buffer cache using the block containing the last record from the
6018 * previous incarnation.
6019 */
6020 Insert = &XLogCtl->Insert;
6021 Insert->PrevBytePos = XLogRecPtrToBytePos(endOfRecoveryInfo->lastRec);
6022 Insert->CurrBytePos = XLogRecPtrToBytePos(EndOfLog);
6023
6024 /*
6025 * Tricky point here: lastPage contains the *last* block that the LastRec
6026 * record spans, not the one it starts in. The last block is indeed the
6027 * one we want to use.
6028 */
6029 if (EndOfLog % XLOG_BLCKSZ != 0)
6030 {
6031 char *page;
6032 int len;
6033 int firstIdx;
6034
6035 firstIdx = XLogRecPtrToBufIdx(EndOfLog);
6036 len = EndOfLog - endOfRecoveryInfo->lastPageBeginPtr;
6037 Assert(len < XLOG_BLCKSZ);
6038
6039 /* Copy the valid part of the last block, and zero the rest */
6040 page = &XLogCtl->pages[firstIdx * XLOG_BLCKSZ];
6041 memcpy(page, endOfRecoveryInfo->lastPage, len);
6042 memset(page + len, 0, XLOG_BLCKSZ - len);
6043
6044 pg_atomic_write_u64(&XLogCtl->xlblocks[firstIdx], endOfRecoveryInfo->lastPageBeginPtr + XLOG_BLCKSZ);
6045 XLogCtl->InitializedUpTo = endOfRecoveryInfo->lastPageBeginPtr + XLOG_BLCKSZ;
6046 }
6047 else
6048 {
6049 /*
6050 * There is no partial block to copy. Just set InitializedUpTo, and
6051 * let the first attempt to insert a log record to initialize the next
6052 * buffer.
6053 */
6054 XLogCtl->InitializedUpTo = EndOfLog;
6055 }
6056
6057 /*
6058 * Update local and shared status. This is OK to do without any locks
6059 * because no other process can be reading or writing WAL yet.
6060 */
6061 LogwrtResult.Write = LogwrtResult.Flush = EndOfLog;
6065 XLogCtl->LogwrtRqst.Write = EndOfLog;
6066 XLogCtl->LogwrtRqst.Flush = EndOfLog;
6067
6068 /*
6069 * Preallocate additional log files, if wanted.
6070 */
6071 PreallocXlogFiles(EndOfLog, newTLI);
6072
6073 /*
6074 * Okay, we're officially UP.
6075 */
6076 InRecovery = false;
6077
6078 /* start the archive_timeout timer and LSN running */
6079 XLogCtl->lastSegSwitchTime = (pg_time_t) time(NULL);
6080 XLogCtl->lastSegSwitchLSN = EndOfLog;
6081
6082 /* also initialize latestCompletedXid, to nextXid - 1 */
6083 LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
6086 LWLockRelease(ProcArrayLock);
6087
6088 /*
6089 * Start up subtrans, if not already done for hot standby. (commit
6090 * timestamps are started below, if necessary.)
6091 */
6093 StartupSUBTRANS(oldestActiveXID);
6094
6095 /*
6096 * Perform end of recovery actions for any SLRUs that need it.
6097 */
6098 TrimCLOG();
6099 TrimMultiXact();
6100
6101 /*
6102 * Reload shared-memory state for prepared transactions. This needs to
6103 * happen before renaming the last partial segment of the old timeline as
6104 * it may be possible that we have to recovery some transactions from it.
6105 */
6107
6108 /* Shut down xlogreader */
6110
6111 /* Enable WAL writes for this backend only. */
6113
6114 /* If necessary, write overwrite-contrecord before doing anything else */
6116 {
6119 }
6120
6121 /*
6122 * Update full_page_writes in shared memory and write an XLOG_FPW_CHANGE
6123 * record before resource manager writes cleanup WAL records or checkpoint
6124 * record is written.
6125 */
6126 Insert->fullPageWrites = lastFullPageWrites;
6128
6129 /*
6130 * Emit checkpoint or end-of-recovery record in XLOG, if required.
6131 */
6132 if (performedWalRecovery)
6133 promoted = PerformRecoveryXLogAction();
6134
6135 /*
6136 * If any of the critical GUCs have changed, log them before we allow
6137 * backends to write WAL.
6138 */
6140
6141 /* If this is archive recovery, perform post-recovery cleanup actions. */
6143 CleanupAfterArchiveRecovery(EndOfLogTLI, EndOfLog, newTLI);
6144
6145 /*
6146 * Local WAL inserts enabled, so it's time to finish initialization of
6147 * commit timestamp.
6148 */
6150
6151 /*
6152 * All done with end-of-recovery actions.
6153 *
6154 * Now allow backends to write WAL and update the control file status in
6155 * consequence. SharedRecoveryState, that controls if backends can write
6156 * WAL, is updated while holding ControlFileLock to prevent other backends
6157 * to look at an inconsistent state of the control file in shared memory.
6158 * There is still a small window during which backends can write WAL and
6159 * the control file is still referring to a system not in DB_IN_PRODUCTION
6160 * state while looking at the on-disk control file.
6161 *
6162 * Also, we use info_lck to update SharedRecoveryState to ensure that
6163 * there are no race conditions concerning visibility of other recent
6164 * updates to shared memory.
6165 */
6166 LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
6168
6172
6174 LWLockRelease(ControlFileLock);
6175
6176 /*
6177 * Shutdown the recovery environment. This must occur after
6178 * RecoverPreparedTransactions() (see notes in lock_twophase_recover())
6179 * and after switching SharedRecoveryState to RECOVERY_STATE_DONE so as
6180 * any session building a snapshot will not rely on KnownAssignedXids as
6181 * RecoveryInProgress() would return false at this stage. This is
6182 * particularly critical for prepared 2PC transactions, that would still
6183 * need to be included in snapshots once recovery has ended.
6184 */
6187
6188 /*
6189 * If there were cascading standby servers connected to us, nudge any wal
6190 * sender processes to notice that we've been promoted.
6191 */
6192 WalSndWakeup(true, true);
6193
6194 /*
6195 * If this was a promotion, request an (online) checkpoint now. This isn't
6196 * required for consistency, but the last restartpoint might be far back,
6197 * and in case of a crash, recovering from it might take a longer than is
6198 * appropriate now that we're not in standby mode anymore.
6199 */
6200 if (promoted)
6202}
static void pg_atomic_write_membarrier_u64(volatile pg_atomic_uint64 *ptr, uint64 val)
Definition: atomics.h:494
TimeLineID findNewestTimeLine(TimeLineID startTLI)
Definition: timeline.c:264
void restoreTimeLineHistoryFiles(TimeLineID begin, TimeLineID end)
Definition: timeline.c:50
void writeTimeLineHistory(TimeLineID newTLI, TimeLineID parentTLI, XLogRecPtr switchpoint, char *reason)
Definition: timeline.c:304
void startup_progress_timeout_handler(void)
Definition: startup.c:303
uint32 TransactionId
Definition: c.h:606
void StartupCLOG(void)
Definition: clog.c:877
void TrimCLOG(void)
Definition: clog.c:892
void StartupCommitTs(void)
Definition: commit_ts.c:632
void CompleteCommitTsInitialization(void)
Definition: commit_ts.c:642
void SyncDataDirectory(void)
Definition: fd.c:3567
#define IsBootstrapProcessingMode()
Definition: miscadmin.h:466
void TrimMultiXact(void)
Definition: multixact.c:2178
void StartupMultiXact(void)
Definition: multixact.c:2153
void StartupReplicationOrigin(void)
Definition: origin.c:703
@ DB_IN_PRODUCTION
Definition: pg_control.h:97
@ DB_IN_CRASH_RECOVERY
Definition: pg_control.h:95
const void size_t len
void pgstat_restore_stats(XLogRecPtr redo)
Definition: pgstat.c:505
void pgstat_discard_stats(void)
Definition: pgstat.c:517
void ProcArrayApplyRecoveryInfo(RunningTransactions running)
Definition: procarray.c:1054
void ProcArrayInitRecovery(TransactionId initializedUptoXID)
Definition: procarray.c:1023
static void set_ps_display(const char *activity)
Definition: ps_status.h:40
void ResetUnloggedRelations(int op)
Definition: reinit.c:47
#define UNLOGGED_RELATION_INIT
Definition: reinit.h:28
#define UNLOGGED_RELATION_CLEANUP
Definition: reinit.h:27
void RelationCacheInitFileRemove(void)
Definition: relcache.c:6819
void StartupReorderBuffer(void)
void StartupReplicationSlots(void)
Definition: slot.c:1924
void DeleteAllExportedSnapshotFiles(void)
Definition: snapmgr.c:1515
void InitRecoveryTransactionEnvironment(void)
Definition: standby.c:94
void ShutdownRecoveryTransactionEnvironment(void)
Definition: standby.c:160
@ SUBXIDS_IN_SUBTRANS
Definition: standby.h:82
XLogRecPtr lastPageBeginPtr
Definition: xlogrecovery.h:111
XLogRecPtr abortedRecPtr
Definition: xlogrecovery.h:120
XLogRecPtr missingContrecPtr
Definition: xlogrecovery.h:121
TimeLineID endOfLogTLI
Definition: xlogrecovery.h:109
TransactionId oldestRunningXid
Definition: standby.h:92
TransactionId nextXid
Definition: standby.h:91
TransactionId latestCompletedXid
Definition: standby.h:95
subxids_array_status subxid_status
Definition: standby.h:90
TransactionId * xids
Definition: standby.h:97
FullTransactionId latestCompletedXid
Definition: transam.h:238
pg_atomic_uint64 logInsertResult
Definition: xlog.c:471
void StartupSUBTRANS(TransactionId oldestActiveXID)
Definition: subtrans.c:309
TimeoutId RegisterTimeout(TimeoutId id, timeout_handler_proc handler)
Definition: timeout.c:505
@ STARTUP_PROGRESS_TIMEOUT
Definition: timeout.h:38
#define TransactionIdRetreat(dest)
Definition: transam.h:141
static void FullTransactionIdRetreat(FullTransactionId *dest)
Definition: transam.h:103
#define XidFromFullTransactionId(x)
Definition: transam.h:48
#define TransactionIdIsValid(xid)
Definition: transam.h:41
#define TransactionIdIsNormal(xid)
Definition: transam.h:42
void RecoverPreparedTransactions(void)
Definition: twophase.c:2089
void restoreTwoPhaseData(void)
Definition: twophase.c:1904
TransactionId PrescanPreparedTransactions(TransactionId **xids_p, int *nxids_p)
Definition: twophase.c:1968
void StandbyRecoverPreparedTransactions(void)
Definition: twophase.c:2048
void WalSndWakeup(bool physical, bool logical)
Definition: walsender.c:3639
void UpdateFullPageWrites(void)
Definition: xlog.c:8166
static char * str_time(pg_time_t tnow)
Definition: xlog.c:5199
static void ValidateXLOGDirectoryStructure(void)
Definition: xlog.c:4099
static XLogRecPtr CreateOverwriteContrecordRecord(XLogRecPtr aborted_lsn, XLogRecPtr pagePtr, TimeLineID newTLI)
Definition: xlog.c:7440
static void XLogReportParameters(void)
Definition: xlog.c:8103
static bool PerformRecoveryXLogAction(void)
Definition: xlog.c:6284
static void CleanupAfterArchiveRecovery(TimeLineID EndOfLogTLI, XLogRecPtr EndOfLog, TimeLineID newTLI)
Definition: xlog.c:5289
static bool lastFullPageWrites
Definition: xlog.c:217
static void XLogInitNewTimeline(TimeLineID endTLI, XLogRecPtr endOfLog, TimeLineID newTLI)
Definition: xlog.c:5214
static void CheckRequiredParameterValues(void)
Definition: xlog.c:5385
static void RemoveTempXlogFiles(void)
Definition: xlog.c:3832
#define TABLESPACE_MAP_OLD
Definition: xlog.h:306
#define TABLESPACE_MAP
Definition: xlog.h:305
#define STANDBY_SIGNAL_FILE
Definition: xlog.h:301
#define BACKUP_LABEL_OLD
Definition: xlog.h:303
#define BACKUP_LABEL_FILE
Definition: xlog.h:302
#define RECOVERY_SIGNAL_FILE
Definition: xlog.h:300
@ RECOVERY_STATE_CRASH
Definition: xlog.h:91
@ RECOVERY_STATE_ARCHIVE
Definition: xlog.h:92
#define XRecOffIsValid(xlrp)
void ShutdownWalRecovery(void)
bool InArchiveRecovery
Definition: xlogrecovery.c:138
void PerformWalRecovery(void)
static XLogRecPtr missingContrecPtr
Definition: xlogrecovery.c:373
static XLogRecPtr abortedRecPtr
Definition: xlogrecovery.c:372
EndOfWalRecoveryInfo * FinishWalRecovery(void)
void InitWalRecovery(ControlFileData *ControlFile, bool *wasShutdown_ptr, bool *haveBackupLabel_ptr, bool *haveTblspcMap_ptr)
Definition: xlogrecovery.c:512
TimeLineID recoveryTargetTLI
Definition: xlogrecovery.c:122
HotStandbyState standbyState
Definition: xlogutils.c:53
bool InRecovery
Definition: xlogutils.c:50
@ STANDBY_DISABLED
Definition: xlogutils.h:52

References abortedRecPtr, EndOfWalRecoveryInfo::abortedRecPtr, AdvanceOldestClogXid(), ArchiveRecoveryRequested, Assert, AuxProcessResourceOwner, BACKUP_LABEL_FILE, BACKUP_LABEL_OLD, ControlFileData::backupEndRequired, ControlFileData::backupStartPoint, ControlFileData::checkPoint, CHECKPOINT_FORCE, ControlFileData::checkPointCopy, CheckRequiredParameterValues(), XLogCtlData::ckptFullXid, CleanupAfterArchiveRecovery(), CompleteCommitTsInitialization(), ControlFile, CreateOverwriteContrecordRecord(), CurrentResourceOwner, DB_IN_ARCHIVE_RECOVERY, DB_IN_CRASH_RECOVERY, DB_IN_PRODUCTION, DB_SHUTDOWNED, DB_SHUTDOWNED_IN_RECOVERY, DB_SHUTDOWNING, DEBUG1, DeleteAllExportedSnapshotFiles(), doPageWrites, durable_rename(), durable_unlink(), EnableHotStandby, EndOfWalRecoveryInfo::endOfLog, EndOfWalRecoveryInfo::endOfLogTLI, ereport, errcode(), ERRCODE_DATA_CORRUPTED, errhint(), errmsg(), errmsg_internal(), FATAL, findNewestTimeLine(), FinishWalRecovery(), FirstNormalUnloggedLSN, XLogwrtRqst::Flush, XLogwrtResult::Flush, CheckPoint::fullPageWrites, FullTransactionIdRetreat(), InArchiveRecovery, XLogCtlData::info_lck, XLogCtlData::InitializedUpTo, InitRecoveryTransactionEnvironment(), InitWalRecovery(), InRecovery, XLogCtlData::Insert, Insert(), XLogCtlData::InsertTimeLineID, InvalidXLogRecPtr, IsBootstrapProcessingMode, IsPostmasterEnvironment, lastFullPageWrites, EndOfWalRecoveryInfo::lastPage, EndOfWalRecoveryInfo::lastPageBeginPtr, EndOfWalRecoveryInfo::lastRec, EndOfWalRecoveryInfo::lastRecTLI, XLogCtlData::lastSegSwitchLSN, XLogCtlData::lastSegSwitchTime, TransamVariablesData::latestCompletedXid, RunningTransactionsData::latestCompletedXid, len, LocalMinRecoveryPoint, LocalMinRecoveryPointTLI, LocalSetXLogInsertAllowed(), LOG, XLogCtlData::logFlushResult, XLogCtlData::logInsertResult, XLogCtlData::logWriteResult, LogwrtResult, XLogCtlData::LogwrtRqst, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), ControlFileData::minRecoveryPoint, ControlFileData::minRecoveryPointTLI, missingContrecPtr, EndOfWalRecoveryInfo::missingContrecPtr, MultiXactSetNextMXact(), CheckPoint::newestCommitTsXid, CheckPoint::nextMulti, CheckPoint::nextMultiOffset, TransamVariablesData::nextOid, CheckPoint::nextOid, TransamVariablesData::nextXid, CheckPoint::nextXid, RunningTransactionsData::nextXid, NOTICE, TransamVariablesData::oidCount, CheckPoint::oldestActiveXid, CheckPoint::oldestCommitTsXid, CheckPoint::oldestMulti, CheckPoint::oldestMultiDB, RunningTransactionsData::oldestRunningXid, CheckPoint::oldestXid, CheckPoint::oldestXidDB, XLogCtlData::pages, PerformRecoveryXLogAction(), PerformWalRecovery(), pg_atomic_write_membarrier_u64(), pg_atomic_write_u64(), pg_usleep(), pgstat_discard_stats(), pgstat_restore_stats(), PreallocXlogFiles(), PrescanPreparedTransactions(), XLogCtlData::PrevTimeLineID, ProcArrayApplyRecoveryInfo(), ProcArrayInitRecovery(), RecoverPreparedTransactions(), RECOVERY_SIGNAL_FILE, EndOfWalRecoveryInfo::recovery_signal_file_found, RECOVERY_STATE_ARCHIVE, RECOVERY_STATE_CRASH, RECOVERY_STATE_DONE, EndOfWalRecoveryInfo::recoveryStopReason, recoveryTargetTLI, CheckPoint::redo, RedoRecPtr, XLogCtlInsert::RedoRecPtr, XLogCtlData::RedoRecPtr, RegisterTimeout(), RelationCacheInitFileRemove(), RemoveTempXlogFiles(), RequestCheckpoint(), ResetUnloggedRelations(), restoreTimeLineHistoryFiles(), restoreTwoPhaseData(), set_ps_display(), SetCommitTsLimit(), SetInstallXLogFileSegmentActive(), SetMultiXactIdLimit(), SetTransactionIdLimit(), XLogCtlData::SharedRecoveryState, ShutdownRecoveryTransactionEnvironment(), ShutdownWalRecovery(), SpinLockAcquire, SpinLockRelease, STANDBY_DISABLED, STANDBY_SIGNAL_FILE, EndOfWalRecoveryInfo::standby_signal_file_found, StandbyRecoverPreparedTransactions(), standbyState, STARTUP_PROGRESS_TIMEOUT, startup_progress_timeout_handler(), StartupCLOG(), StartupCommitTs(), StartupMultiXact(), StartupReorderBuffer(), StartupReplicationOrigin(), StartupReplicationSlots(), StartupSUBTRANS(), ControlFileData::state, str_time(), RunningTransactionsData::subxcnt, RunningTransactionsData::subxid_status, SUBXIDS_IN_SUBTRANS, SyncDataDirectory(), TABLESPACE_MAP, TABLESPACE_MAP_OLD, CheckPoint::ThisTimeLineID, CheckPoint::time, ControlFileData::time, ControlFileData::track_commit_timestamp, TransactionIdIsNormal, TransactionIdIsValid, TransactionIdRetreat, TransamVariables, TrimCLOG(), TrimMultiXact(), UNLOGGED_RELATION_CLEANUP, UNLOGGED_RELATION_INIT, XLogCtlData::unloggedLSN, ControlFileData::unloggedLSN, UpdateControlFile(), UpdateFullPageWrites(), ValidateXLOGDirectoryStructure(), WalSndWakeup(), XLogwrtRqst::Write, XLogwrtResult::Write, writeTimeLineHistory(), RunningTransactionsData::xcnt, XidFromFullTransactionId, RunningTransactionsData::xids, XLogCtlData::xlblocks, XLogCtl, XLogInitNewTimeline(), XLogRecPtrIsInvalid, XLogRecPtrToBufIdx, XLogRecPtrToBytePos(), XLogReportParameters(), and XRecOffIsValid.

Referenced by InitPostgres(), and StartupProcessMain().

◆ str_time()

static char * str_time ( pg_time_t  tnow)
static

Definition at line 5199 of file xlog.c.

5200{
5201 char *buf = palloc(128);
5202
5203 pg_strftime(buf, 128,
5204 "%Y-%m-%d %H:%M:%S %Z",
5205 pg_localtime(&tnow, log_timezone));
5206
5207 return buf;
5208}
static char * buf
Definition: pg_test_fsync.c:72
size_t pg_strftime(char *s, size_t maxsize, const char *format, const struct pg_tm *t)
Definition: strftime.c:128
struct pg_tm * pg_localtime(const pg_time_t *timep, const pg_tz *tz)
Definition: localtime.c:1344
PGDLLIMPORT pg_tz * log_timezone
Definition: pgtz.c:31

References buf, log_timezone, palloc(), pg_localtime(), and pg_strftime().

Referenced by StartupXLOG().

◆ SwitchIntoArchiveRecovery()

void SwitchIntoArchiveRecovery ( XLogRecPtr  EndRecPtr,
TimeLineID  replayTLI 
)

Definition at line 6209 of file xlog.c.

6210{
6211 /* initialize minRecoveryPoint to this record */
6212 LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
6214 if (ControlFile->minRecoveryPoint < EndRecPtr)
6215 {
6216 ControlFile->minRecoveryPoint = EndRecPtr;
6217 ControlFile->minRecoveryPointTLI = replayTLI;
6218 }
6219 /* update local copy */
6222
6223 /*
6224 * The startup process can update its local copy of minRecoveryPoint from
6225 * this point.
6226 */
6228
6230
6231 /*
6232 * We update SharedRecoveryState while holding the lock on ControlFileLock
6233 * so both states are consistent in shared memory.
6234 */
6238
6239 LWLockRelease(ControlFileLock);
6240}
static bool updateMinRecoveryPoint
Definition: xlog.c:648

References ControlFile, DB_IN_ARCHIVE_RECOVERY, XLogCtlData::info_lck, LocalMinRecoveryPoint, LocalMinRecoveryPointTLI, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), ControlFileData::minRecoveryPoint, ControlFileData::minRecoveryPointTLI, RECOVERY_STATE_ARCHIVE, XLogCtlData::SharedRecoveryState, SpinLockAcquire, SpinLockRelease, ControlFileData::state, UpdateControlFile(), updateMinRecoveryPoint, and XLogCtl.

Referenced by ReadRecord().

◆ update_checkpoint_display()

static void update_checkpoint_display ( int  flags,
bool  restartpoint,
bool  reset 
)
static

Definition at line 6824 of file xlog.c.

6825{
6826 /*
6827 * The status is reported only for end-of-recovery and shutdown
6828 * checkpoints or shutdown restartpoints. Updating the ps display is
6829 * useful in those situations as it may not be possible to rely on
6830 * pg_stat_activity to see the status of the checkpointer or the startup
6831 * process.
6832 */
6834 return;
6835
6836 if (reset)
6837 set_ps_display("");
6838 else
6839 {
6840 char activitymsg[128];
6841
6842 snprintf(activitymsg, sizeof(activitymsg), "performing %s%s%s",
6843 (flags & CHECKPOINT_END_OF_RECOVERY) ? "end-of-recovery " : "",
6844 (flags & CHECKPOINT_IS_SHUTDOWN) ? "shutdown " : "",
6845 restartpoint ? "restartpoint" : "checkpoint");
6846 set_ps_display(activitymsg);
6847 }
6848}

References CHECKPOINT_END_OF_RECOVERY, CHECKPOINT_IS_SHUTDOWN, reset(), set_ps_display(), and snprintf.

Referenced by CreateCheckPoint(), and CreateRestartPoint().

◆ UpdateCheckPointDistanceEstimate()

static void UpdateCheckPointDistanceEstimate ( uint64  nbytes)
static

Definition at line 6786 of file xlog.c.

6787{
6788 /*
6789 * To estimate the number of segments consumed between checkpoints, keep a
6790 * moving average of the amount of WAL generated in previous checkpoint
6791 * cycles. However, if the load is bursty, with quiet periods and busy
6792 * periods, we want to cater for the peak load. So instead of a plain
6793 * moving average, let the average decline slowly if the previous cycle
6794 * used less WAL than estimated, but bump it up immediately if it used
6795 * more.
6796 *
6797 * When checkpoints are triggered by max_wal_size, this should converge to
6798 * CheckpointSegments * wal_segment_size,
6799 *
6800 * Note: This doesn't pay any attention to what caused the checkpoint.
6801 * Checkpoints triggered manually with CHECKPOINT command, or by e.g.
6802 * starting a base backup, are counted the same as those created
6803 * automatically. The slow-decline will largely mask them out, if they are
6804 * not frequent. If they are frequent, it seems reasonable to count them
6805 * in as any others; if you issue a manual checkpoint every 5 minutes and
6806 * never let a timed checkpoint happen, it makes sense to base the
6807 * preallocation on that 5 minute interval rather than whatever
6808 * checkpoint_timeout is set to.
6809 */
6810 PrevCheckPointDistance = nbytes;
6811 if (CheckPointDistanceEstimate < nbytes)
6813 else
6815 (0.90 * CheckPointDistanceEstimate + 0.10 * (double) nbytes);
6816}

References CheckPointDistanceEstimate, and PrevCheckPointDistance.

Referenced by CreateCheckPoint(), and CreateRestartPoint().

◆ UpdateControlFile()

static void UpdateControlFile ( void  )
static

Definition at line 4559 of file xlog.c.

4560{
4562}
void update_controlfile(const char *DataDir, ControlFileData *ControlFile, bool do_sync)

References ControlFile, DataDir, and update_controlfile().

Referenced by CreateCheckPoint(), CreateEndOfRecoveryRecord(), CreateRestartPoint(), ReachedEndOfBackup(), StartupXLOG(), SwitchIntoArchiveRecovery(), UpdateMinRecoveryPoint(), xlog_redo(), and XLogReportParameters().

◆ UpdateFullPageWrites()

void UpdateFullPageWrites ( void  )

Definition at line 8166 of file xlog.c.

8167{
8169 bool recoveryInProgress;
8170
8171 /*
8172 * Do nothing if full_page_writes has not been changed.
8173 *
8174 * It's safe to check the shared full_page_writes without the lock,
8175 * because we assume that there is no concurrently running process which
8176 * can update it.
8177 */
8178 if (fullPageWrites == Insert->fullPageWrites)
8179 return;
8180
8181 /*
8182 * Perform this outside critical section so that the WAL insert
8183 * initialization done by RecoveryInProgress() doesn't trigger an
8184 * assertion failure.
8185 */
8186 recoveryInProgress = RecoveryInProgress();
8187
8189
8190 /*
8191 * It's always safe to take full page images, even when not strictly
8192 * required, but not the other round. So if we're setting full_page_writes
8193 * to true, first set it true and then write the WAL record. If we're
8194 * setting it to false, first write the WAL record and then set the global
8195 * flag.
8196 */
8197 if (fullPageWrites)
8198 {
8200 Insert->fullPageWrites = true;
8202 }
8203
8204 /*
8205 * Write an XLOG_FPW_CHANGE record. This allows us to keep track of
8206 * full_page_writes during archive recovery, if required.
8207 */
8208 if (XLogStandbyInfoActive() && !recoveryInProgress)
8209 {
8211 XLogRegisterData((char *) (&fullPageWrites), sizeof(bool));
8212
8213 XLogInsert(RM_XLOG_ID, XLOG_FPW_CHANGE);
8214 }
8215
8216 if (!fullPageWrites)
8217 {
8219 Insert->fullPageWrites = false;
8221 }
8223}
#define XLOG_FPW_CHANGE
Definition: pg_control.h:76

References END_CRIT_SECTION, fullPageWrites, XLogCtlData::Insert, Insert(), RecoveryInProgress(), START_CRIT_SECTION, WALInsertLockAcquireExclusive(), WALInsertLockRelease(), XLOG_FPW_CHANGE, XLogBeginInsert(), XLogCtl, XLogInsert(), XLogRegisterData(), and XLogStandbyInfoActive.

Referenced by StartupXLOG(), and UpdateSharedMemoryConfig().

◆ UpdateLastRemovedPtr()

static void UpdateLastRemovedPtr ( char *  filename)
static

Definition at line 3812 of file xlog.c.

3813{
3814 uint32 tli;
3815 XLogSegNo segno;
3816
3818
3820 if (segno > XLogCtl->lastRemovedSegNo)
3821 XLogCtl->lastRemovedSegNo = segno;
3823}
static void XLogFromFileName(const char *fname, TimeLineID *tli, XLogSegNo *logSegNo, int wal_segsz_bytes)

References filename, XLogCtlData::info_lck, XLogCtlData::lastRemovedSegNo, SpinLockAcquire, SpinLockRelease, wal_segment_size, XLogCtl, and XLogFromFileName().

Referenced by RemoveOldXlogFiles().

◆ UpdateMinRecoveryPoint()

static void UpdateMinRecoveryPoint ( XLogRecPtr  lsn,
bool  force 
)
static

Definition at line 2722 of file xlog.c.

2723{
2724 /* Quick check using our local copy of the variable */
2725 if (!updateMinRecoveryPoint || (!force && lsn <= LocalMinRecoveryPoint))
2726 return;
2727
2728 /*
2729 * An invalid minRecoveryPoint means that we need to recover all the WAL,
2730 * i.e., we're doing crash recovery. We never modify the control file's
2731 * value in that case, so we can short-circuit future checks here too. The
2732 * local values of minRecoveryPoint and minRecoveryPointTLI should not be
2733 * updated until crash recovery finishes. We only do this for the startup
2734 * process as it should not update its own reference of minRecoveryPoint
2735 * until it has finished crash recovery to make sure that all WAL
2736 * available is replayed in this case. This also saves from extra locks
2737 * taken on the control file from the startup process.
2738 */
2740 {
2741 updateMinRecoveryPoint = false;
2742 return;
2743 }
2744
2745 LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
2746
2747 /* update local copy */
2750
2752 updateMinRecoveryPoint = false;
2753 else if (force || LocalMinRecoveryPoint < lsn)
2754 {
2755 XLogRecPtr newMinRecoveryPoint;
2756 TimeLineID newMinRecoveryPointTLI;
2757
2758 /*
2759 * To avoid having to update the control file too often, we update it
2760 * all the way to the last record being replayed, even though 'lsn'
2761 * would suffice for correctness. This also allows the 'force' case
2762 * to not need a valid 'lsn' value.
2763 *
2764 * Another important reason for doing it this way is that the passed
2765 * 'lsn' value could be bogus, i.e., past the end of available WAL, if
2766 * the caller got it from a corrupted heap page. Accepting such a
2767 * value as the min recovery point would prevent us from coming up at
2768 * all. Instead, we just log a warning and continue with recovery.
2769 * (See also the comments about corrupt LSNs in XLogFlush.)
2770 */
2771 newMinRecoveryPoint = GetCurrentReplayRecPtr(&newMinRecoveryPointTLI);
2772 if (!force && newMinRecoveryPoint < lsn)
2773 elog(WARNING,
2774 "xlog min recovery request %X/%X is past current point %X/%X",
2775 LSN_FORMAT_ARGS(lsn), LSN_FORMAT_ARGS(newMinRecoveryPoint));
2776
2777 /* update control file */
2778 if (ControlFile->minRecoveryPoint < newMinRecoveryPoint)
2779 {
2780 ControlFile->minRecoveryPoint = newMinRecoveryPoint;
2781 ControlFile->minRecoveryPointTLI = newMinRecoveryPointTLI;
2783 LocalMinRecoveryPoint = newMinRecoveryPoint;
2784 LocalMinRecoveryPointTLI = newMinRecoveryPointTLI;
2785
2787 (errmsg_internal("updated min recovery point to %X/%X on timeline %u",
2788 LSN_FORMAT_ARGS(newMinRecoveryPoint),
2789 newMinRecoveryPointTLI)));
2790 }
2791 }
2792 LWLockRelease(ControlFileLock);
2793}
XLogRecPtr GetCurrentReplayRecPtr(TimeLineID *replayEndTLI)

References ControlFile, DEBUG2, elog, ereport, errmsg_internal(), GetCurrentReplayRecPtr(), InRecovery, LocalMinRecoveryPoint, LocalMinRecoveryPointTLI, LSN_FORMAT_ARGS, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), ControlFileData::minRecoveryPoint, ControlFileData::minRecoveryPointTLI, UpdateControlFile(), updateMinRecoveryPoint, WARNING, and XLogRecPtrIsInvalid.

Referenced by CreateRestartPoint(), XLogFlush(), and XLogInitNewTimeline().

◆ ValidateXLOGDirectoryStructure()

static void ValidateXLOGDirectoryStructure ( void  )
static

Definition at line 4099 of file xlog.c.

4100{
4101 char path[MAXPGPATH];
4102 struct stat stat_buf;
4103
4104 /* Check for pg_wal; if it doesn't exist, error out */
4105 if (stat(XLOGDIR, &stat_buf) != 0 ||
4106 !S_ISDIR(stat_buf.st_mode))
4107 ereport(FATAL,
4109 errmsg("required WAL directory \"%s\" does not exist",
4110 XLOGDIR)));
4111
4112 /* Check for archive_status */
4113 snprintf(path, MAXPGPATH, XLOGDIR "/archive_status");
4114 if (stat(path, &stat_buf) == 0)
4115 {
4116 /* Check for weird cases where it exists but isn't a directory */
4117 if (!S_ISDIR(stat_buf.st_mode))
4118 ereport(FATAL,
4120 errmsg("required WAL directory \"%s\" does not exist",
4121 path)));
4122 }
4123 else
4124 {
4125 ereport(LOG,
4126 (errmsg("creating missing WAL directory \"%s\"", path)));
4127 if (MakePGDirectory(path) < 0)
4128 ereport(FATAL,
4130 errmsg("could not create missing directory \"%s\": %m",
4131 path)));
4132 }
4133
4134 /* Check for summaries */
4135 snprintf(path, MAXPGPATH, XLOGDIR "/summaries");
4136 if (stat(path, &stat_buf) == 0)
4137 {
4138 /* Check for weird cases where it exists but isn't a directory */
4139 if (!S_ISDIR(stat_buf.st_mode))
4140 ereport(FATAL,
4141 (errmsg("required WAL directory \"%s\" does not exist",
4142 path)));
4143 }
4144 else
4145 {
4146 ereport(LOG,
4147 (errmsg("creating missing WAL directory \"%s\"", path)));
4148 if (MakePGDirectory(path) < 0)
4149 ereport(FATAL,
4150 (errmsg("could not create missing directory \"%s\": %m",
4151 path)));
4152 }
4153}
int MakePGDirectory(const char *directoryName)
Definition: fd.c:3936
#define S_ISDIR(m)
Definition: win32_port.h:325

References ereport, errcode_for_file_access(), errmsg(), FATAL, LOG, MakePGDirectory(), MAXPGPATH, S_ISDIR, snprintf, stat::st_mode, stat, and XLOGDIR.

Referenced by StartupXLOG().

◆ WaitXLogInsertionsToFinish()

static XLogRecPtr WaitXLogInsertionsToFinish ( XLogRecPtr  upto)
static

Definition at line 1504 of file xlog.c.

1505{
1506 uint64 bytepos;
1507 XLogRecPtr inserted;
1508 XLogRecPtr reservedUpto;
1509 XLogRecPtr finishedUpto;
1511 int i;
1512
1513 if (MyProc == NULL)
1514 elog(PANIC, "cannot wait without a PGPROC structure");
1515
1516 /*
1517 * Check if there's any work to do. Use a barrier to ensure we get the
1518 * freshest value.
1519 */
1521 if (upto <= inserted)
1522 return inserted;
1523
1524 /* Read the current insert position */
1525 SpinLockAcquire(&Insert->insertpos_lck);
1526 bytepos = Insert->CurrBytePos;
1527 SpinLockRelease(&Insert->insertpos_lck);
1528 reservedUpto = XLogBytePosToEndRecPtr(bytepos);
1529
1530 /*
1531 * No-one should request to flush a piece of WAL that hasn't even been
1532 * reserved yet. However, it can happen if there is a block with a bogus
1533 * LSN on disk, for example. XLogFlush checks for that situation and
1534 * complains, but only after the flush. Here we just assume that to mean
1535 * that all WAL that has been reserved needs to be finished. In this
1536 * corner-case, the return value can be smaller than 'upto' argument.
1537 */
1538 if (upto > reservedUpto)
1539 {
1540 ereport(LOG,
1541 (errmsg("request to flush past end of generated WAL; request %X/%X, current position %X/%X",
1542 LSN_FORMAT_ARGS(upto), LSN_FORMAT_ARGS(reservedUpto))));
1543 upto = reservedUpto;
1544 }
1545
1546 /*
1547 * Loop through all the locks, sleeping on any in-progress insert older
1548 * than 'upto'.
1549 *
1550 * finishedUpto is our return value, indicating the point upto which all
1551 * the WAL insertions have been finished. Initialize it to the head of
1552 * reserved WAL, and as we iterate through the insertion locks, back it
1553 * out for any insertion that's still in progress.
1554 */
1555 finishedUpto = reservedUpto;
1556 for (i = 0; i < NUM_XLOGINSERT_LOCKS; i++)
1557 {
1558 XLogRecPtr insertingat = InvalidXLogRecPtr;
1559
1560 do
1561 {
1562 /*
1563 * See if this insertion is in progress. LWLockWaitForVar will
1564 * wait for the lock to be released, or for the 'value' to be set
1565 * by a LWLockUpdateVar call. When a lock is initially acquired,
1566 * its value is 0 (InvalidXLogRecPtr), which means that we don't
1567 * know where it's inserting yet. We will have to wait for it. If
1568 * it's a small insertion, the record will most likely fit on the
1569 * same page and the inserter will release the lock without ever
1570 * calling LWLockUpdateVar. But if it has to sleep, it will
1571 * advertise the insertion point with LWLockUpdateVar before
1572 * sleeping.
1573 *
1574 * In this loop we are only waiting for insertions that started
1575 * before WaitXLogInsertionsToFinish was called. The lack of
1576 * memory barriers in the loop means that we might see locks as
1577 * "unused" that have since become used. This is fine because
1578 * they only can be used for later insertions that we would not
1579 * want to wait on anyway. Not taking a lock to acquire the
1580 * current insertingAt value means that we might see older
1581 * insertingAt values. This is also fine, because if we read a
1582 * value too old, we will add ourselves to the wait queue, which
1583 * contains atomic operations.
1584 */
1585 if (LWLockWaitForVar(&WALInsertLocks[i].l.lock,
1587 insertingat, &insertingat))
1588 {
1589 /* the lock was free, so no insertion in progress */
1590 insertingat = InvalidXLogRecPtr;
1591 break;
1592 }
1593
1594 /*
1595 * This insertion is still in progress. Have to wait, unless the
1596 * inserter has proceeded past 'upto'.
1597 */
1598 } while (insertingat < upto);
1599
1600 if (insertingat != InvalidXLogRecPtr && insertingat < finishedUpto)
1601 finishedUpto = insertingat;
1602 }
1603
1604 /*
1605 * Advance the limit we know to have been inserted and return the freshest
1606 * value we know of, which might be beyond what we requested if somebody
1607 * is concurrently doing this with an 'upto' pointer ahead of us.
1608 */
1610 finishedUpto);
1611
1612 return finishedUpto;
1613}
static uint64 pg_atomic_monotonic_advance_u64(volatile pg_atomic_uint64 *ptr, uint64 target)
Definition: atomics.h:585
bool LWLockWaitForVar(LWLock *lock, pg_atomic_uint64 *valptr, uint64 oldval, uint64 *newval)
Definition: lwlock.c:1584
PGPROC * MyProc
Definition: proc.c:66
pg_atomic_uint64 insertingAt
Definition: xlog.c:370

References elog, ereport, errmsg(), i, XLogCtlData::Insert, Insert(), WALInsertLock::insertingAt, InvalidXLogRecPtr, WALInsertLockPadded::l, LOG, XLogCtlData::logInsertResult, LSN_FORMAT_ARGS, LWLockWaitForVar(), MyProc, NUM_XLOGINSERT_LOCKS, PANIC, pg_atomic_monotonic_advance_u64(), pg_atomic_read_membarrier_u64(), SpinLockAcquire, SpinLockRelease, WALInsertLocks, XLogBytePosToEndRecPtr(), and XLogCtl.

Referenced by AdvanceXLInsertBuffer(), XLogBackgroundFlush(), and XLogFlush().

◆ WALInsertLockAcquire()

static void WALInsertLockAcquire ( void  )
static

Definition at line 1371 of file xlog.c.

1372{
1373 bool immed;
1374
1375 /*
1376 * It doesn't matter which of the WAL insertion locks we acquire, so try
1377 * the one we used last time. If the system isn't particularly busy, it's
1378 * a good bet that it's still available, and it's good to have some
1379 * affinity to a particular lock so that you don't unnecessarily bounce
1380 * cache lines between processes when there's no contention.
1381 *
1382 * If this is the first time through in this backend, pick a lock
1383 * (semi-)randomly. This allows the locks to be used evenly if you have a
1384 * lot of very short connections.
1385 */
1386 static int lockToTry = -1;
1387
1388 if (lockToTry == -1)
1389 lockToTry = MyProcNumber % NUM_XLOGINSERT_LOCKS;
1390 MyLockNo = lockToTry;
1391
1392 /*
1393 * The insertingAt value is initially set to 0, as we don't know our
1394 * insert location yet.
1395 */
1397 if (!immed)
1398 {
1399 /*
1400 * If we couldn't get the lock immediately, try another lock next
1401 * time. On a system with more insertion locks than concurrent
1402 * inserters, this causes all the inserters to eventually migrate to a
1403 * lock that no-one else is using. On a system with more inserters
1404 * than locks, it still helps to distribute the inserters evenly
1405 * across the locks.
1406 */
1407 lockToTry = (lockToTry + 1) % NUM_XLOGINSERT_LOCKS;
1408 }
1409}
ProcNumber MyProcNumber
Definition: globals.c:89
static int MyLockNo
Definition: xlog.c:651

References LW_EXCLUSIVE, LWLockAcquire(), MyLockNo, MyProcNumber, NUM_XLOGINSERT_LOCKS, and WALInsertLocks.

Referenced by CreateOverwriteContrecordRecord(), and XLogInsertRecord().

◆ WALInsertLockAcquireExclusive()

static void WALInsertLockAcquireExclusive ( void  )
static

Definition at line 1416 of file xlog.c.

1417{
1418 int i;
1419
1420 /*
1421 * When holding all the locks, all but the last lock's insertingAt
1422 * indicator is set to 0xFFFFFFFFFFFFFFFF, which is higher than any real
1423 * XLogRecPtr value, to make sure that no-one blocks waiting on those.
1424 */
1425 for (i = 0; i < NUM_XLOGINSERT_LOCKS - 1; i++)
1426 {
1431 }
1432 /* Variable value reset to 0 at release */
1434
1435 holdingAllLocks = true;
1436}
#define PG_UINT64_MAX
Definition: c.h:547
void LWLockUpdateVar(LWLock *lock, pg_atomic_uint64 *valptr, uint64 val)
Definition: lwlock.c:1720
static bool holdingAllLocks
Definition: xlog.c:652

References holdingAllLocks, i, WALInsertLock::insertingAt, WALInsertLockPadded::l, LW_EXCLUSIVE, LWLockAcquire(), LWLockUpdateVar(), NUM_XLOGINSERT_LOCKS, PG_UINT64_MAX, and WALInsertLocks.

Referenced by CreateCheckPoint(), CreateEndOfRecoveryRecord(), CreateRestartPoint(), do_pg_abort_backup(), do_pg_backup_start(), do_pg_backup_stop(), UpdateFullPageWrites(), and XLogInsertRecord().

◆ WALInsertLockRelease()

static void WALInsertLockRelease ( void  )
static

Definition at line 1445 of file xlog.c.

1446{
1447 if (holdingAllLocks)
1448 {
1449 int i;
1450
1451 for (i = 0; i < NUM_XLOGINSERT_LOCKS; i++)
1454 0);
1455
1456 holdingAllLocks = false;
1457 }
1458 else
1459 {
1462 0);
1463 }
1464}
void LWLockReleaseClearVar(LWLock *lock, pg_atomic_uint64 *valptr, uint64 val)
Definition: lwlock.c:1854

References holdingAllLocks, i, WALInsertLock::insertingAt, WALInsertLockPadded::l, LWLockReleaseClearVar(), MyLockNo, NUM_XLOGINSERT_LOCKS, and WALInsertLocks.

Referenced by CreateCheckPoint(), CreateEndOfRecoveryRecord(), CreateOverwriteContrecordRecord(), CreateRestartPoint(), do_pg_abort_backup(), do_pg_backup_start(), do_pg_backup_stop(), UpdateFullPageWrites(), and XLogInsertRecord().

◆ WALInsertLockUpdateInsertingAt()

static void WALInsertLockUpdateInsertingAt ( XLogRecPtr  insertingAt)
static

Definition at line 1471 of file xlog.c.

1472{
1473 if (holdingAllLocks)
1474 {
1475 /*
1476 * We use the last lock to mark our actual position, see comments in
1477 * WALInsertLockAcquireExclusive.
1478 */
1481 insertingAt);
1482 }
1483 else
1486 insertingAt);
1487}

References holdingAllLocks, WALInsertLock::insertingAt, WALInsertLockPadded::l, LWLockUpdateVar(), MyLockNo, NUM_XLOGINSERT_LOCKS, and WALInsertLocks.

Referenced by GetXLogBuffer().

◆ WALReadFromBuffers()

Size WALReadFromBuffers ( char *  dstbuf,
XLogRecPtr  startptr,
Size  count,
TimeLineID  tli 
)

Definition at line 1748 of file xlog.c.

1750{
1751 char *pdst = dstbuf;
1752 XLogRecPtr recptr = startptr;
1753 XLogRecPtr inserted;
1754 Size nbytes = count;
1755
1757 return 0;
1758
1759 Assert(!XLogRecPtrIsInvalid(startptr));
1760
1761 /*
1762 * Caller should ensure that the requested data has been inserted into WAL
1763 * buffers before we try to read it.
1764 */
1766 if (startptr + count > inserted)
1767 ereport(ERROR,
1768 errmsg("cannot read past end of generated WAL: requested %X/%X, current position %X/%X",
1769 LSN_FORMAT_ARGS(startptr + count),
1770 LSN_FORMAT_ARGS(inserted)));
1771
1772 /*
1773 * Loop through the buffers without a lock. For each buffer, atomically
1774 * read and verify the end pointer, then copy the data out, and finally
1775 * re-read and re-verify the end pointer.
1776 *
1777 * Once a page is evicted, it never returns to the WAL buffers, so if the
1778 * end pointer matches the expected end pointer before and after we copy
1779 * the data, then the right page must have been present during the data
1780 * copy. Read barriers are necessary to ensure that the data copy actually
1781 * happens between the two verification steps.
1782 *
1783 * If either verification fails, we simply terminate the loop and return
1784 * with the data that had been already copied out successfully.
1785 */
1786 while (nbytes > 0)
1787 {
1788 uint32 offset = recptr % XLOG_BLCKSZ;
1789 int idx = XLogRecPtrToBufIdx(recptr);
1790 XLogRecPtr expectedEndPtr;
1791 XLogRecPtr endptr;
1792 const char *page;
1793 const char *psrc;
1794 Size npagebytes;
1795
1796 /*
1797 * Calculate the end pointer we expect in the xlblocks array if the
1798 * correct page is present.
1799 */
1800 expectedEndPtr = recptr + (XLOG_BLCKSZ - offset);
1801
1802 /*
1803 * First verification step: check that the correct page is present in
1804 * the WAL buffers.
1805 */
1807 if (expectedEndPtr != endptr)
1808 break;
1809
1810 /*
1811 * The correct page is present (or was at the time the endptr was
1812 * read; must re-verify later). Calculate pointer to source data and
1813 * determine how much data to read from this page.
1814 */
1815 page = XLogCtl->pages + idx * (Size) XLOG_BLCKSZ;
1816 psrc = page + offset;
1817 npagebytes = Min(nbytes, XLOG_BLCKSZ - offset);
1818
1819 /*
1820 * Ensure that the data copy and the first verification step are not
1821 * reordered.
1822 */
1824
1825 /* data copy */
1826 memcpy(pdst, psrc, npagebytes);
1827
1828 /*
1829 * Ensure that the data copy and the second verification step are not
1830 * reordered.
1831 */
1833
1834 /*
1835 * Second verification step: check that the page we read from wasn't
1836 * evicted while we were copying the data.
1837 */
1839 if (expectedEndPtr != endptr)
1840 break;
1841
1842 pdst += npagebytes;
1843 recptr += npagebytes;
1844 nbytes -= npagebytes;
1845 }
1846
1847 Assert(pdst - dstbuf <= count);
1848
1849 return pdst - dstbuf;
1850}
#define pg_read_barrier()
Definition: atomics.h:156
#define Min(x, y)
Definition: c.h:958
TimeLineID GetWALInsertionTimeLine(void)
Definition: xlog.c:6520

References Assert, ereport, errmsg(), ERROR, GetWALInsertionTimeLine(), idx(), XLogCtlData::logInsertResult, LSN_FORMAT_ARGS, Min, XLogCtlData::pages, pg_atomic_read_u64(), pg_read_barrier, RecoveryInProgress(), XLogCtlData::xlblocks, XLogCtl, XLogRecPtrIsInvalid, and XLogRecPtrToBufIdx.

Referenced by XLogSendPhysical().

◆ WriteControlFile()

static void WriteControlFile ( void  )
static

Definition at line 4239 of file xlog.c.

4240{
4241 int fd;
4242 char buffer[PG_CONTROL_FILE_SIZE]; /* need not be aligned */
4243
4244 /*
4245 * Initialize version and compatibility-check fields
4246 */
4249
4250 ControlFile->maxAlign = MAXIMUM_ALIGNOF;
4252
4253 ControlFile->blcksz = BLCKSZ;
4254 ControlFile->relseg_size = RELSEG_SIZE;
4255 ControlFile->xlog_blcksz = XLOG_BLCKSZ;
4257
4260
4263
4265
4266 /* Contents are protected with a CRC */
4269 (char *) ControlFile,
4270 offsetof(ControlFileData, crc));
4272
4273 /*
4274 * We write out PG_CONTROL_FILE_SIZE bytes into pg_control, zero-padding
4275 * the excess over sizeof(ControlFileData). This reduces the odds of
4276 * premature-EOF errors when reading pg_control. We'll still fail when we
4277 * check the contents of the file, but hopefully with a more specific
4278 * error than "couldn't read pg_control".
4279 */
4280 memset(buffer, 0, PG_CONTROL_FILE_SIZE);
4281 memcpy(buffer, ControlFile, sizeof(ControlFileData));
4282
4284 O_RDWR | O_CREAT | O_EXCL | PG_BINARY);
4285 if (fd < 0)
4286 ereport(PANIC,
4288 errmsg("could not create file \"%s\": %m",
4290
4291 errno = 0;
4292 pgstat_report_wait_start(WAIT_EVENT_CONTROL_FILE_WRITE);
4294 {
4295 /* if write didn't set errno, assume problem is no disk space */
4296 if (errno == 0)
4297 errno = ENOSPC;
4298 ereport(PANIC,
4300 errmsg("could not write to file \"%s\": %m",
4302 }
4304
4305 pgstat_report_wait_start(WAIT_EVENT_CONTROL_FILE_SYNC);
4306 if (pg_fsync(fd) != 0)
4307 ereport(PANIC,
4309 errmsg("could not fsync file \"%s\": %m",
4312
4313 if (close(fd) != 0)
4314 ereport(PANIC,
4316 errmsg("could not close file \"%s\": %m",
4318}
#define FLOAT8PASSBYVAL
Definition: c.h:589
#define PG_CONTROL_FILE_SIZE
Definition: pg_control.h:250

References BasicOpenFile(), ControlFileData::blcksz, CATALOG_VERSION_NO, ControlFileData::catalog_version_no, close, COMP_CRC32C, ControlFile, ControlFileData::crc, crc, ereport, errcode_for_file_access(), errmsg(), fd(), FIN_CRC32C, ControlFileData::float8ByVal, FLOAT8PASSBYVAL, ControlFileData::floatFormat, FLOATFORMAT_VALUE, INDEX_MAX_KEYS, ControlFileData::indexMaxKeys, INIT_CRC32C, ControlFileData::loblksize, LOBLKSIZE, ControlFileData::maxAlign, ControlFileData::nameDataLen, NAMEDATALEN, PANIC, PG_BINARY, PG_CONTROL_FILE_SIZE, PG_CONTROL_VERSION, ControlFileData::pg_control_version, pg_fsync(), pgstat_report_wait_end(), pgstat_report_wait_start(), ControlFileData::relseg_size, TOAST_MAX_CHUNK_SIZE, ControlFileData::toast_max_chunk_size, wal_segment_size, write, ControlFileData::xlog_blcksz, XLOG_CONTROL_FILE, and ControlFileData::xlog_seg_size.

Referenced by BootStrapXLOG().

◆ xlog_redo()

void xlog_redo ( XLogReaderState record)

Definition at line 8235 of file xlog.c.

8236{
8237 uint8 info = XLogRecGetInfo(record) & ~XLR_INFO_MASK;
8238 XLogRecPtr lsn = record->EndRecPtr;
8239
8240 /*
8241 * In XLOG rmgr, backup blocks are only used by XLOG_FPI and
8242 * XLOG_FPI_FOR_HINT records.
8243 */
8244 Assert(info == XLOG_FPI || info == XLOG_FPI_FOR_HINT ||
8245 !XLogRecHasAnyBlockRefs(record));
8246
8247 if (info == XLOG_NEXTOID)
8248 {
8249 Oid nextOid;
8250
8251 /*
8252 * We used to try to take the maximum of TransamVariables->nextOid and
8253 * the recorded nextOid, but that fails if the OID counter wraps
8254 * around. Since no OID allocation should be happening during replay
8255 * anyway, better to just believe the record exactly. We still take
8256 * OidGenLock while setting the variable, just in case.
8257 */
8258 memcpy(&nextOid, XLogRecGetData(record), sizeof(Oid));
8259 LWLockAcquire(OidGenLock, LW_EXCLUSIVE);
8260 TransamVariables->nextOid = nextOid;
8262 LWLockRelease(OidGenLock);
8263 }
8264 else if (info == XLOG_CHECKPOINT_SHUTDOWN)
8265 {
8266 CheckPoint checkPoint;
8267 TimeLineID replayTLI;
8268
8269 memcpy(&checkPoint, XLogRecGetData(record), sizeof(CheckPoint));
8270 /* In a SHUTDOWN checkpoint, believe the counters exactly */
8271 LWLockAcquire(XidGenLock, LW_EXCLUSIVE);
8272 TransamVariables->nextXid = checkPoint.nextXid;
8273 LWLockRelease(XidGenLock);
8274 LWLockAcquire(OidGenLock, LW_EXCLUSIVE);
8275 TransamVariables->nextOid = checkPoint.nextOid;
8277 LWLockRelease(OidGenLock);
8279 checkPoint.nextMultiOffset);
8280
8282 checkPoint.oldestMultiDB);
8283
8284 /*
8285 * No need to set oldestClogXid here as well; it'll be set when we
8286 * redo an xl_clog_truncate if it changed since initialization.
8287 */
8288 SetTransactionIdLimit(checkPoint.oldestXid, checkPoint.oldestXidDB);
8289
8290 /*
8291 * If we see a shutdown checkpoint while waiting for an end-of-backup
8292 * record, the backup was canceled and the end-of-backup record will
8293 * never arrive.
8294 */
8298 ereport(PANIC,
8299 (errmsg("online backup was canceled, recovery cannot continue")));
8300
8301 /*
8302 * If we see a shutdown checkpoint, we know that nothing was running
8303 * on the primary at this point. So fake-up an empty running-xacts
8304 * record and use that here and now. Recover additional standby state
8305 * for prepared transactions.
8306 */
8308 {
8309 TransactionId *xids;
8310 int nxids;
8311 TransactionId oldestActiveXID;
8312 TransactionId latestCompletedXid;
8314
8315 oldestActiveXID = PrescanPreparedTransactions(&xids, &nxids);
8316
8317 /* Update pg_subtrans entries for any prepared transactions */
8319
8320 /*
8321 * Construct a RunningTransactions snapshot representing a shut
8322 * down server, with only prepared transactions still alive. We're
8323 * never overflowed at this point because all subxids are listed
8324 * with their parent prepared transactions.
8325 */
8326 running.xcnt = nxids;
8327 running.subxcnt = 0;
8329 running.nextXid = XidFromFullTransactionId(checkPoint.nextXid);
8330 running.oldestRunningXid = oldestActiveXID;
8331 latestCompletedXid = XidFromFullTransactionId(checkPoint.nextXid);
8332 TransactionIdRetreat(latestCompletedXid);
8333 Assert(TransactionIdIsNormal(latestCompletedXid));
8334 running.latestCompletedXid = latestCompletedXid;
8335 running.xids = xids;
8336
8338 }
8339
8340 /* ControlFile->checkPointCopy always tracks the latest ckpt XID */
8341 LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
8343 LWLockRelease(ControlFileLock);
8344
8345 /* Update shared-memory copy of checkpoint XID/epoch */
8347 XLogCtl->ckptFullXid = checkPoint.nextXid;
8349
8350 /*
8351 * We should've already switched to the new TLI before replaying this
8352 * record.
8353 */
8354 (void) GetCurrentReplayRecPtr(&replayTLI);
8355 if (checkPoint.ThisTimeLineID != replayTLI)
8356 ereport(PANIC,
8357 (errmsg("unexpected timeline ID %u (should be %u) in shutdown checkpoint record",
8358 checkPoint.ThisTimeLineID, replayTLI)));
8359
8360 RecoveryRestartPoint(&checkPoint, record);
8361 }
8362 else if (info == XLOG_CHECKPOINT_ONLINE)
8363 {
8364 CheckPoint checkPoint;
8365 TimeLineID replayTLI;
8366
8367 memcpy(&checkPoint, XLogRecGetData(record), sizeof(CheckPoint));
8368 /* In an ONLINE checkpoint, treat the XID counter as a minimum */
8369 LWLockAcquire(XidGenLock, LW_EXCLUSIVE);
8371 checkPoint.nextXid))
8372 TransamVariables->nextXid = checkPoint.nextXid;
8373 LWLockRelease(XidGenLock);
8374
8375 /*
8376 * We ignore the nextOid counter in an ONLINE checkpoint, preferring
8377 * to track OID assignment through XLOG_NEXTOID records. The nextOid
8378 * counter is from the start of the checkpoint and might well be stale
8379 * compared to later XLOG_NEXTOID records. We could try to take the
8380 * maximum of the nextOid counter and our latest value, but since
8381 * there's no particular guarantee about the speed with which the OID
8382 * counter wraps around, that's a risky thing to do. In any case,
8383 * users of the nextOid counter are required to avoid assignment of
8384 * duplicates, so that a somewhat out-of-date value should be safe.
8385 */
8386
8387 /* Handle multixact */
8389 checkPoint.nextMultiOffset);
8390
8391 /*
8392 * NB: This may perform multixact truncation when replaying WAL
8393 * generated by an older primary.
8394 */
8396 checkPoint.oldestMultiDB);
8398 checkPoint.oldestXid))
8400 checkPoint.oldestXidDB);
8401 /* ControlFile->checkPointCopy always tracks the latest ckpt XID */
8402 LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
8404 LWLockRelease(ControlFileLock);
8405
8406 /* Update shared-memory copy of checkpoint XID/epoch */
8408 XLogCtl->ckptFullXid = checkPoint.nextXid;
8410
8411 /* TLI should not change in an on-line checkpoint */
8412 (void) GetCurrentReplayRecPtr(&replayTLI);
8413 if (checkPoint.ThisTimeLineID != replayTLI)
8414 ereport(PANIC,
8415 (errmsg("unexpected timeline ID %u (should be %u) in online checkpoint record",
8416 checkPoint.ThisTimeLineID, replayTLI)));
8417
8418 RecoveryRestartPoint(&checkPoint, record);
8419 }
8420 else if (info == XLOG_OVERWRITE_CONTRECORD)
8421 {
8422 /* nothing to do here, handled in xlogrecovery_redo() */
8423 }
8424 else if (info == XLOG_END_OF_RECOVERY)
8425 {
8426 xl_end_of_recovery xlrec;
8427 TimeLineID replayTLI;
8428
8429 memcpy(&xlrec, XLogRecGetData(record), sizeof(xl_end_of_recovery));
8430
8431 /*
8432 * For Hot Standby, we could treat this like a Shutdown Checkpoint,
8433 * but this case is rarer and harder to test, so the benefit doesn't
8434 * outweigh the potential extra cost of maintenance.
8435 */
8436
8437 /*
8438 * We should've already switched to the new TLI before replaying this
8439 * record.
8440 */
8441 (void) GetCurrentReplayRecPtr(&replayTLI);
8442 if (xlrec.ThisTimeLineID != replayTLI)
8443 ereport(PANIC,
8444 (errmsg("unexpected timeline ID %u (should be %u) in end-of-recovery record",
8445 xlrec.ThisTimeLineID, replayTLI)));
8446 }
8447 else if (info == XLOG_NOOP)
8448 {
8449 /* nothing to do here */
8450 }
8451 else if (info == XLOG_SWITCH)
8452 {
8453 /* nothing to do here */
8454 }
8455 else if (info == XLOG_RESTORE_POINT)
8456 {
8457 /* nothing to do here, handled in xlogrecovery.c */
8458 }
8459 else if (info == XLOG_FPI || info == XLOG_FPI_FOR_HINT)
8460 {
8461 /*
8462 * XLOG_FPI records contain nothing else but one or more block
8463 * references. Every block reference must include a full-page image
8464 * even if full_page_writes was disabled when the record was generated
8465 * - otherwise there would be no point in this record.
8466 *
8467 * XLOG_FPI_FOR_HINT records are generated when a page needs to be
8468 * WAL-logged because of a hint bit update. They are only generated
8469 * when checksums and/or wal_log_hints are enabled. They may include
8470 * no full-page images if full_page_writes was disabled when they were
8471 * generated. In this case there is nothing to do here.
8472 *
8473 * No recovery conflicts are generated by these generic records - if a
8474 * resource manager needs to generate conflicts, it has to define a
8475 * separate WAL record type and redo routine.
8476 */
8477 for (uint8 block_id = 0; block_id <= XLogRecMaxBlockId(record); block_id++)
8478 {
8479 Buffer buffer;
8480
8481 if (!XLogRecHasBlockImage(record, block_id))
8482 {
8483 if (info == XLOG_FPI)
8484 elog(ERROR, "XLOG_FPI record did not contain a full-page image");
8485 continue;
8486 }
8487
8488 if (XLogReadBufferForRedo(record, block_id, &buffer) != BLK_RESTORED)
8489 elog(ERROR, "unexpected XLogReadBufferForRedo result when restoring backup block");
8490 UnlockReleaseBuffer(buffer);
8491 }
8492 }
8493 else if (info == XLOG_BACKUP_END)
8494 {
8495 /* nothing to do here, handled in xlogrecovery_redo() */
8496 }
8497 else if (info == XLOG_PARAMETER_CHANGE)
8498 {
8499 xl_parameter_change xlrec;
8500
8501 /* Update our copy of the parameters in pg_control */
8502 memcpy(&xlrec, XLogRecGetData(record), sizeof(xl_parameter_change));
8503
8504 /*
8505 * Invalidate logical slots if we are in hot standby and the primary
8506 * does not have a WAL level sufficient for logical decoding. No need
8507 * to search for potentially conflicting logically slots if standby is
8508 * running with wal_level lower than logical, because in that case, we
8509 * would have either disallowed creation of logical slots or
8510 * invalidated existing ones.
8511 */
8512 if (InRecovery && InHotStandby &&
8513 xlrec.wal_level < WAL_LEVEL_LOGICAL &&
8516 0, InvalidOid,
8518
8519 LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
8527
8528 /*
8529 * Update minRecoveryPoint to ensure that if recovery is aborted, we
8530 * recover back up to this point before allowing hot standby again.
8531 * This is important if the max_* settings are decreased, to ensure
8532 * you don't run queries against the WAL preceding the change. The
8533 * local copies cannot be updated as long as crash recovery is
8534 * happening and we expect all the WAL to be replayed.
8535 */
8537 {
8540 }
8542 {
8543 TimeLineID replayTLI;
8544
8545 (void) GetCurrentReplayRecPtr(&replayTLI);
8547 ControlFile->minRecoveryPointTLI = replayTLI;
8548 }
8549
8553
8555 LWLockRelease(ControlFileLock);
8556
8557 /* Check to see if any parameter change gives a problem on recovery */
8559 }
8560 else if (info == XLOG_FPW_CHANGE)
8561 {
8562 bool fpw;
8563
8564 memcpy(&fpw, XLogRecGetData(record), sizeof(bool));
8565
8566 /*
8567 * Update the LSN of the last replayed XLOG_FPW_CHANGE record so that
8568 * do_pg_backup_start() and do_pg_backup_stop() can check whether
8569 * full_page_writes has been disabled during online backup.
8570 */
8571 if (!fpw)
8572 {
8577 }
8578
8579 /* Keep track of full_page_writes */
8580 lastFullPageWrites = fpw;
8581 }
8582 else if (info == XLOG_CHECKPOINT_REDO)
8583 {
8584 /* nothing to do here, just for informational purposes */
8585 }
8586}
int Buffer
Definition: buf.h:23
void UnlockReleaseBuffer(Buffer buffer)
Definition: bufmgr.c:4941
uint8_t uint8
Definition: c.h:483
void CommitTsParameterChange(bool newvalue, bool oldvalue)
Definition: commit_ts.c:664
void MultiXactAdvanceOldest(MultiXactId oldestMulti, Oid oldestMultiDB)
Definition: multixact.c:2536
void MultiXactAdvanceNextMXact(MultiXactId minMulti, MultiXactOffset minMultiOffset)
Definition: multixact.c:2511
#define XLOG_RESTORE_POINT
Definition: pg_control.h:75
#define XLOG_FPI
Definition: pg_control.h:79
#define XLOG_FPI_FOR_HINT
Definition: pg_control.h:78
#define XLOG_NEXTOID
Definition: pg_control.h:71
#define XLOG_NOOP
Definition: pg_control.h:70
#define XLOG_PARAMETER_CHANGE
Definition: pg_control.h:74
@ RS_INVAL_WAL_LEVEL
Definition: slot.h:58
bool TransactionIdPrecedes(TransactionId id1, TransactionId id2)
Definition: transam.c:280
#define FullTransactionIdPrecedes(a, b)
Definition: transam.h:51
static void RecoveryRestartPoint(const CheckPoint *checkPoint, XLogReaderState *record)
Definition: xlog.c:7550
@ WAL_LEVEL_LOGICAL
Definition: xlog.h:76
#define XLogRecGetInfo(decoder)
Definition: xlogreader.h:410
#define XLogRecGetData(decoder)
Definition: xlogreader.h:415
#define XLogRecMaxBlockId(decoder)
Definition: xlogreader.h:418
#define XLogRecHasBlockImage(decoder, block_id)
Definition: xlogreader.h:423
#define XLogRecHasAnyBlockRefs(decoder)
Definition: xlogreader.h:417
XLogRedoAction XLogReadBufferForRedo(XLogReaderState *record, uint8 block_id, Buffer *buf)
Definition: xlogutils.c:314
@ STANDBY_INITIALIZED
Definition: xlogutils.h:53
#define InHotStandby
Definition: xlogutils.h:60
@ BLK_RESTORED
Definition: xlogutils.h:76

References ArchiveRecoveryRequested, Assert, ControlFileData::backupEndPoint, ControlFileData::backupStartPoint, BLK_RESTORED, ControlFileData::checkPointCopy, CheckRequiredParameterValues(), XLogCtlData::ckptFullXid, CommitTsParameterChange(), ControlFile, elog, XLogReaderState::EndRecPtr, ereport, errmsg(), ERROR, FullTransactionIdPrecedes, GetCurrentReplayRecPtr(), InArchiveRecovery, XLogCtlData::info_lck, InHotStandby, InRecovery, InvalidateObsoleteReplicationSlots(), InvalidOid, InvalidTransactionId, InvalidXLogRecPtr, XLogCtlData::lastFpwDisableRecPtr, lastFullPageWrites, RunningTransactionsData::latestCompletedXid, LocalMinRecoveryPoint, LocalMinRecoveryPointTLI, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), xl_parameter_change::max_locks_per_xact, ControlFileData::max_locks_per_xact, xl_parameter_change::max_prepared_xacts, ControlFileData::max_prepared_xacts, xl_parameter_change::max_wal_senders, ControlFileData::max_wal_senders, xl_parameter_change::max_worker_processes, ControlFileData::max_worker_processes, xl_parameter_change::MaxConnections, ControlFileData::MaxConnections, ControlFileData::minRecoveryPoint, ControlFileData::minRecoveryPointTLI, MultiXactAdvanceNextMXact(), MultiXactAdvanceOldest(), MultiXactSetNextMXact(), CheckPoint::nextMulti, CheckPoint::nextMultiOffset, TransamVariablesData::nextOid, CheckPoint::nextOid, TransamVariablesData::nextXid, CheckPoint::nextXid, RunningTransactionsData::nextXid, TransamVariablesData::oidCount, CheckPoint::oldestMulti, CheckPoint::oldestMultiDB, RunningTransactionsData::oldestRunningXid, TransamVariablesData::oldestXid, CheckPoint::oldestXid, CheckPoint::oldestXidDB, PANIC, PrescanPreparedTransactions(), ProcArrayApplyRecoveryInfo(), XLogReaderState::ReadRecPtr, RecoveryRestartPoint(), RS_INVAL_WAL_LEVEL, SetTransactionIdLimit(), SpinLockAcquire, SpinLockRelease, STANDBY_INITIALIZED, StandbyRecoverPreparedTransactions(), standbyState, RunningTransactionsData::subxcnt, RunningTransactionsData::subxid_status, SUBXIDS_IN_SUBTRANS, xl_end_of_recovery::ThisTimeLineID, CheckPoint::ThisTimeLineID, xl_parameter_change::track_commit_timestamp, ControlFileData::track_commit_timestamp, TransactionIdIsNormal, TransactionIdPrecedes(), TransactionIdRetreat, TransamVariables, UnlockReleaseBuffer(), UpdateControlFile(), wal_level, xl_parameter_change::wal_level, ControlFileData::wal_level, WAL_LEVEL_LOGICAL, xl_parameter_change::wal_log_hints, ControlFileData::wal_log_hints, RunningTransactionsData::xcnt, XidFromFullTransactionId, RunningTransactionsData::xids, XLOG_BACKUP_END, XLOG_CHECKPOINT_ONLINE, XLOG_CHECKPOINT_REDO, XLOG_CHECKPOINT_SHUTDOWN, XLOG_END_OF_RECOVERY, XLOG_FPI, XLOG_FPI_FOR_HINT, XLOG_FPW_CHANGE, XLOG_NEXTOID, XLOG_NOOP, XLOG_OVERWRITE_CONTRECORD, XLOG_PARAMETER_CHANGE, XLOG_RESTORE_POINT, XLOG_SWITCH, XLogCtl, XLogReadBufferForRedo(), XLogRecGetData, XLogRecGetInfo, XLogRecHasAnyBlockRefs, XLogRecHasBlockImage, XLogRecMaxBlockId, and XLogRecPtrIsInvalid.

◆ XLogBackgroundFlush()

bool XLogBackgroundFlush ( void  )

Definition at line 2990 of file xlog.c.

2991{
2992 XLogwrtRqst WriteRqst;
2993 bool flexible = true;
2994 static TimestampTz lastflush;
2996 int flushblocks;
2997 TimeLineID insertTLI;
2998
2999 /* XLOG doesn't need flushing during recovery */
3000 if (RecoveryInProgress())
3001 return false;
3002
3003 /*
3004 * Since we're not in recovery, InsertTimeLineID is set and can't change,
3005 * so we can read it without a lock.
3006 */
3007 insertTLI = XLogCtl->InsertTimeLineID;
3008
3009 /* read updated LogwrtRqst */
3011 WriteRqst = XLogCtl->LogwrtRqst;
3013
3014 /* back off to last completed page boundary */
3015 WriteRqst.Write -= WriteRqst.Write % XLOG_BLCKSZ;
3016
3017 /* if we have already flushed that far, consider async commit records */
3019 if (WriteRqst.Write <= LogwrtResult.Flush)
3020 {
3022 WriteRqst.Write = XLogCtl->asyncXactLSN;
3024 flexible = false; /* ensure it all gets written */
3025 }
3026
3027 /*
3028 * If already known flushed, we're done. Just need to check if we are
3029 * holding an open file handle to a logfile that's no longer in use,
3030 * preventing the file from being deleted.
3031 */
3032 if (WriteRqst.Write <= LogwrtResult.Flush)
3033 {
3034 if (openLogFile >= 0)
3035 {
3038 {
3039 XLogFileClose();
3040 }
3041 }
3042 return false;
3043 }
3044
3045 /*
3046 * Determine how far to flush WAL, based on the wal_writer_delay and
3047 * wal_writer_flush_after GUCs.
3048 *
3049 * Note that XLogSetAsyncXactLSN() performs similar calculation based on
3050 * wal_writer_flush_after, to decide when to wake us up. Make sure the
3051 * logic is the same in both places if you change this.
3052 */
3054 flushblocks =
3055 WriteRqst.Write / XLOG_BLCKSZ - LogwrtResult.Flush / XLOG_BLCKSZ;
3056
3057 if (WalWriterFlushAfter == 0 || lastflush == 0)
3058 {
3059 /* first call, or block based limits disabled */
3060 WriteRqst.Flush = WriteRqst.Write;
3061 lastflush = now;
3062 }
3063 else if (TimestampDifferenceExceeds(lastflush, now, WalWriterDelay))
3064 {
3065 /*
3066 * Flush the writes at least every WalWriterDelay ms. This is
3067 * important to bound the amount of time it takes for an asynchronous
3068 * commit to hit disk.
3069 */
3070 WriteRqst.Flush = WriteRqst.Write;
3071 lastflush = now;
3072 }
3073 else if (flushblocks >= WalWriterFlushAfter)
3074 {
3075 /* exceeded wal_writer_flush_after blocks, flush */
3076 WriteRqst.Flush = WriteRqst.Write;
3077 lastflush = now;
3078 }
3079 else
3080 {
3081 /* no flushing, this time round */
3082 WriteRqst.Flush = 0;
3083 }
3084
3085#ifdef WAL_DEBUG
3086 if (XLOG_DEBUG)
3087 elog(LOG, "xlog bg flush request write %X/%X; flush: %X/%X, current is write %X/%X; flush %X/%X",
3088 LSN_FORMAT_ARGS(WriteRqst.Write),
3089 LSN_FORMAT_ARGS(WriteRqst.Flush),
3092#endif
3093
3095
3096 /* now wait for any in-progress insertions to finish and get write lock */
3098 LWLockAcquire(WALWriteLock, LW_EXCLUSIVE);
3100 if (WriteRqst.Write > LogwrtResult.Write ||
3101 WriteRqst.Flush > LogwrtResult.Flush)
3102 {
3103 XLogWrite(WriteRqst, insertTLI, flexible);
3104 }
3105 LWLockRelease(WALWriteLock);
3106
3108
3109 /* wake up walsenders now that we've released heavily contended locks */
3111
3112 /*
3113 * Great, done. To take some work off the critical path, try to initialize
3114 * as many of the no-longer-needed WAL buffers for future use as we can.
3115 */
3116 AdvanceXLInsertBuffer(InvalidXLogRecPtr, insertTLI, true);
3117
3118 /*
3119 * If we determined that we need to write data, but somebody else
3120 * wrote/flushed already, it should be considered as being active, to
3121 * avoid hibernating too early.
3122 */
3123 return true;
3124}
bool TimestampDifferenceExceeds(TimestampTz start_time, TimestampTz stop_time, int msec)
Definition: timestamp.c:1780
Datum now(PG_FUNCTION_ARGS)
Definition: timestamp.c:1608
XLogRecPtr asyncXactLSN
Definition: xlog.c:458
static void WalSndWakeupProcessRequests(bool physical, bool logical)
Definition: walsender.h:65
int WalWriterFlushAfter
Definition: walwriter.c:70
int WalWriterDelay
Definition: walwriter.c:69
#define XLByteInPrevSeg(xlrp, logSegNo, wal_segsz_bytes)

References AdvanceXLInsertBuffer(), XLogCtlData::asyncXactLSN, elog, END_CRIT_SECTION, XLogwrtRqst::Flush, XLogwrtResult::Flush, GetCurrentTimestamp(), XLogCtlData::info_lck, XLogCtlData::InsertTimeLineID, InvalidXLogRecPtr, LOG, LogwrtResult, XLogCtlData::LogwrtRqst, LSN_FORMAT_ARGS, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), now(), openLogFile, openLogSegNo, RecoveryInProgress(), RefreshXLogWriteResult, SpinLockAcquire, SpinLockRelease, START_CRIT_SECTION, TimestampDifferenceExceeds(), WaitXLogInsertionsToFinish(), wal_segment_size, WalSndWakeupProcessRequests(), WalWriterDelay, WalWriterFlushAfter, XLogwrtRqst::Write, XLogwrtResult::Write, XLByteInPrevSeg, XLogCtl, XLogFileClose(), and XLogWrite().

Referenced by WalSndWaitForWal(), and WalWriterMain().

◆ XLogBytePosToEndRecPtr()

static XLogRecPtr XLogBytePosToEndRecPtr ( uint64  bytepos)
static

Definition at line 1898 of file xlog.c.

1899{
1900 uint64 fullsegs;
1901 uint64 fullpages;
1902 uint64 bytesleft;
1903 uint32 seg_offset;
1904 XLogRecPtr result;
1905
1906 fullsegs = bytepos / UsableBytesInSegment;
1907 bytesleft = bytepos % UsableBytesInSegment;
1908
1909 if (bytesleft < XLOG_BLCKSZ - SizeOfXLogLongPHD)
1910 {
1911 /* fits on first page of segment */
1912 if (bytesleft == 0)
1913 seg_offset = 0;
1914 else
1915 seg_offset = bytesleft + SizeOfXLogLongPHD;
1916 }
1917 else
1918 {
1919 /* account for the first page on segment with long header */
1920 seg_offset = XLOG_BLCKSZ;
1921 bytesleft -= XLOG_BLCKSZ - SizeOfXLogLongPHD;
1922
1923 fullpages = bytesleft / UsableBytesInPage;
1924 bytesleft = bytesleft % UsableBytesInPage;
1925
1926 if (bytesleft == 0)
1927 seg_offset += fullpages * XLOG_BLCKSZ + bytesleft;
1928 else
1929 seg_offset += fullpages * XLOG_BLCKSZ + bytesleft + SizeOfXLogShortPHD;
1930 }
1931
1932 XLogSegNoOffsetToRecPtr(fullsegs, seg_offset, wal_segment_size, result);
1933
1934 return result;
1935}
#define XLogSegNoOffsetToRecPtr(segno, offset, wal_segsz_bytes, dest)

References SizeOfXLogLongPHD, SizeOfXLogShortPHD, UsableBytesInPage, UsableBytesInSegment, wal_segment_size, and XLogSegNoOffsetToRecPtr.

Referenced by ReserveXLogInsertLocation(), ReserveXLogSwitch(), and WaitXLogInsertionsToFinish().

◆ XLogBytePosToRecPtr()

static XLogRecPtr XLogBytePosToRecPtr ( uint64  bytepos)
static

Definition at line 1858 of file xlog.c.

1859{
1860 uint64 fullsegs;
1861 uint64 fullpages;
1862 uint64 bytesleft;
1863 uint32 seg_offset;
1864 XLogRecPtr result;
1865
1866 fullsegs = bytepos / UsableBytesInSegment;
1867 bytesleft = bytepos % UsableBytesInSegment;
1868
1869 if (bytesleft < XLOG_BLCKSZ - SizeOfXLogLongPHD)
1870 {
1871 /* fits on first page of segment */
1872 seg_offset = bytesleft + SizeOfXLogLongPHD;
1873 }
1874 else
1875 {
1876 /* account for the first page on segment with long header */
1877 seg_offset = XLOG_BLCKSZ;
1878 bytesleft -= XLOG_BLCKSZ - SizeOfXLogLongPHD;
1879
1880 fullpages = bytesleft / UsableBytesInPage;
1881 bytesleft = bytesleft % UsableBytesInPage;
1882
1883 seg_offset += fullpages * XLOG_BLCKSZ + bytesleft + SizeOfXLogShortPHD;
1884 }
1885
1886 XLogSegNoOffsetToRecPtr(fullsegs, seg_offset, wal_segment_size, result);
1887
1888 return result;
1889}

References SizeOfXLogLongPHD, SizeOfXLogShortPHD, UsableBytesInPage, UsableBytesInSegment, wal_segment_size, and XLogSegNoOffsetToRecPtr.

Referenced by CreateCheckPoint(), GetXLogInsertRecPtr(), ReserveXLogInsertLocation(), and ReserveXLogSwitch().

◆ XLogCheckpointNeeded()

bool XLogCheckpointNeeded ( XLogSegNo  new_segno)

Definition at line 2290 of file xlog.c.

2291{
2292 XLogSegNo old_segno;
2293
2295
2296 if (new_segno >= old_segno + (uint64) (CheckPointSegments - 1))
2297 return true;
2298 return false;
2299}

References CheckPointSegments, RedoRecPtr, wal_segment_size, and XLByteToSeg.

Referenced by XLogPageRead(), and XLogWrite().

◆ XLOGChooseNumBuffers()

static int XLOGChooseNumBuffers ( void  )
static

Definition at line 4621 of file xlog.c.

4622{
4623 int xbuffers;
4624
4625 xbuffers = NBuffers / 32;
4626 if (xbuffers > (wal_segment_size / XLOG_BLCKSZ))
4627 xbuffers = (wal_segment_size / XLOG_BLCKSZ);
4628 if (xbuffers < 8)
4629 xbuffers = 8;
4630 return xbuffers;
4631}

References NBuffers, and wal_segment_size.

Referenced by check_wal_buffers(), and XLOGShmemSize().

◆ XLogFileClose()

static void XLogFileClose ( void  )
static

Definition at line 3639 of file xlog.c.

3640{
3641 Assert(openLogFile >= 0);
3642
3643 /*
3644 * WAL segment files will not be re-read in normal operation, so we advise
3645 * the OS to release any cached pages. But do not do so if WAL archiving
3646 * or streaming is active, because archiver and walsender process could
3647 * use the cache to read the WAL segment.
3648 */
3649#if defined(USE_POSIX_FADVISE) && defined(POSIX_FADV_DONTNEED)
3650 if (!XLogIsNeeded() && (io_direct_flags & IO_DIRECT_WAL) == 0)
3651 (void) posix_fadvise(openLogFile, 0, 0, POSIX_FADV_DONTNEED);
3652#endif
3653
3654 if (close(openLogFile) != 0)
3655 {
3656 char xlogfname[MAXFNAMELEN];
3657 int save_errno = errno;
3658
3660 errno = save_errno;
3661 ereport(PANIC,
3663 errmsg("could not close file \"%s\": %m", xlogfname)));
3664 }
3665
3666 openLogFile = -1;
3668}
void ReleaseExternalFD(void)
Definition: fd.c:1238

References Assert, close, ereport, errcode_for_file_access(), errmsg(), io_direct_flags, IO_DIRECT_WAL, MAXFNAMELEN, openLogFile, openLogSegNo, openLogTLI, PANIC, ReleaseExternalFD(), wal_segment_size, XLogFileName(), and XLogIsNeeded.

Referenced by assign_wal_sync_method(), XLogBackgroundFlush(), and XLogWrite().

◆ XLogFileCopy()

static void XLogFileCopy ( TimeLineID  destTLI,
XLogSegNo  destsegno,
TimeLineID  srcTLI,
XLogSegNo  srcsegno,
int  upto 
)
static

Definition at line 3418 of file xlog.c.

3421{
3422 char path[MAXPGPATH];
3423 char tmppath[MAXPGPATH];
3424 PGAlignedXLogBlock buffer;
3425 int srcfd;
3426 int fd;
3427 int nbytes;
3428
3429 /*
3430 * Open the source file
3431 */
3432 XLogFilePath(path, srcTLI, srcsegno, wal_segment_size);
3433 srcfd = OpenTransientFile(path, O_RDONLY | PG_BINARY);
3434 if (srcfd < 0)
3435 ereport(ERROR,
3437 errmsg("could not open file \"%s\": %m", path)));
3438
3439 /*
3440 * Copy into a temp file name.
3441 */
3442 snprintf(tmppath, MAXPGPATH, XLOGDIR "/xlogtemp.%d", (int) getpid());
3443
3444 unlink(tmppath);
3445
3446 /* do not use get_sync_bit() here --- want to fsync only at end of fill */
3447 fd = OpenTransientFile(tmppath, O_RDWR | O_CREAT | O_EXCL | PG_BINARY);
3448 if (fd < 0)
3449 ereport(ERROR,
3451 errmsg("could not create file \"%s\": %m", tmppath)));
3452
3453 /*
3454 * Do the data copying.
3455 */
3456 for (nbytes = 0; nbytes < wal_segment_size; nbytes += sizeof(buffer))
3457 {
3458 int nread;
3459
3460 nread = upto - nbytes;
3461
3462 /*
3463 * The part that is not read from the source file is filled with
3464 * zeros.
3465 */
3466 if (nread < sizeof(buffer))
3467 memset(buffer.data, 0, sizeof(buffer));
3468
3469 if (nread > 0)
3470 {
3471 int r;
3472
3473 if (nread > sizeof(buffer))
3474 nread = sizeof(buffer);
3475 pgstat_report_wait_start(WAIT_EVENT_WAL_COPY_READ);
3476 r = read(srcfd, buffer.data, nread);
3477 if (r != nread)
3478 {
3479 if (r < 0)
3480 ereport(ERROR,
3482 errmsg("could not read file \"%s\": %m",
3483 path)));
3484 else
3485 ereport(ERROR,
3487 errmsg("could not read file \"%s\": read %d of %zu",
3488 path, r, (Size) nread)));
3489 }
3491 }
3492 errno = 0;
3493 pgstat_report_wait_start(WAIT_EVENT_WAL_COPY_WRITE);
3494 if ((int) write(fd, buffer.data, sizeof(buffer)) != (int) sizeof(buffer))
3495 {
3496 int save_errno = errno;
3497
3498 /*
3499 * If we fail to make the file, delete it to release disk space
3500 */
3501 unlink(tmppath);
3502 /* if write didn't set errno, assume problem is no disk space */
3503 errno = save_errno ? save_errno : ENOSPC;
3504
3505 ereport(ERROR,
3507 errmsg("could not write to file \"%s\": %m", tmppath)));
3508 }
3510 }
3511
3512 pgstat_report_wait_start(WAIT_EVENT_WAL_COPY_SYNC);
3513 if (pg_fsync(fd) != 0)
3516 errmsg("could not fsync file \"%s\": %m", tmppath)));
3518
3519 if (CloseTransientFile(fd) != 0)
3520 ereport(ERROR,
3522 errmsg("could not close file \"%s\": %m", tmppath)));
3523
3524 if (CloseTransientFile(srcfd) != 0)
3525 ereport(ERROR,
3527 errmsg("could not close file \"%s\": %m", path)));
3528
3529 /*
3530 * Now move the segment into place with its final name.
3531 */
3532 if (!InstallXLogFileSegment(&destsegno, tmppath, false, 0, destTLI))
3533 elog(ERROR, "InstallXLogFileSegment should not have failed");
3534}
int CloseTransientFile(int fd)
Definition: fd.c:2831
int data_sync_elevel(int elevel)
Definition: fd.c:3959
int OpenTransientFile(const char *fileName, int fileFlags)
Definition: fd.c:2655
char data[XLOG_BLCKSZ]
Definition: c.h:1102

References CloseTransientFile(), PGAlignedXLogBlock::data, data_sync_elevel(), elog, ereport, errcode(), ERRCODE_DATA_CORRUPTED, errcode_for_file_access(), errmsg(), ERROR, fd(), InstallXLogFileSegment(), MAXPGPATH, OpenTransientFile(), PG_BINARY, pg_fsync(), pgstat_report_wait_end(), pgstat_report_wait_start(), read, snprintf, wal_segment_size, write, XLOGDIR, and XLogFilePath().

Referenced by XLogInitNewTimeline().

◆ XLogFileInit()

int XLogFileInit ( XLogSegNo  logsegno,
TimeLineID  logtli 
)

Definition at line 3380 of file xlog.c.

3381{
3382 bool ignore_added;
3383 char path[MAXPGPATH];
3384 int fd;
3385
3386 Assert(logtli != 0);
3387
3388 fd = XLogFileInitInternal(logsegno, logtli, &ignore_added, path);
3389 if (fd >= 0)
3390 return fd;
3391
3392 /* Now open original target segment (might not be file I just made) */
3393 fd = BasicOpenFile(path, O_RDWR | PG_BINARY | O_CLOEXEC |
3395 if (fd < 0)
3396 ereport(ERROR,
3398 errmsg("could not open file \"%s\": %m", path)));
3399 return fd;
3400}
#define O_CLOEXEC
Definition: win32_port.h:359

References Assert, BasicOpenFile(), ereport, errcode_for_file_access(), errmsg(), ERROR, fd(), get_sync_bit(), MAXPGPATH, O_CLOEXEC, PG_BINARY, wal_sync_method, and XLogFileInitInternal().

Referenced by BootStrapXLOG(), XLogInitNewTimeline(), XLogWalRcvWrite(), and XLogWrite().

◆ XLogFileInitInternal()

static int XLogFileInitInternal ( XLogSegNo  logsegno,
TimeLineID  logtli,
bool *  added,
char *  path 
)
static

Definition at line 3210 of file xlog.c.

3212{
3213 char tmppath[MAXPGPATH];
3214 XLogSegNo installed_segno;
3215 XLogSegNo max_segno;
3216 int fd;
3217 int save_errno;
3218 int open_flags = O_RDWR | O_CREAT | O_EXCL | PG_BINARY;
3219
3220 Assert(logtli != 0);
3221
3222 XLogFilePath(path, logtli, logsegno, wal_segment_size);
3223
3224 /*
3225 * Try to use existent file (checkpoint maker may have created it already)
3226 */
3227 *added = false;
3228 fd = BasicOpenFile(path, O_RDWR | PG_BINARY | O_CLOEXEC |
3230 if (fd < 0)
3231 {
3232 if (errno != ENOENT)
3233 ereport(ERROR,
3235 errmsg("could not open file \"%s\": %m", path)));
3236 }
3237 else
3238 return fd;
3239
3240 /*
3241 * Initialize an empty (all zeroes) segment. NOTE: it is possible that
3242 * another process is doing the same thing. If so, we will end up
3243 * pre-creating an extra log segment. That seems OK, and better than
3244 * holding the lock throughout this lengthy process.
3245 */
3246 elog(DEBUG2, "creating and filling new WAL file");
3247
3248 snprintf(tmppath, MAXPGPATH, XLOGDIR "/xlogtemp.%d", (int) getpid());
3249
3250 unlink(tmppath);
3251
3253 open_flags |= PG_O_DIRECT;
3254
3255 /* do not use get_sync_bit() here --- want to fsync only at end of fill */
3256 fd = BasicOpenFile(tmppath, open_flags);
3257 if (fd < 0)
3258 ereport(ERROR,
3260 errmsg("could not create file \"%s\": %m", tmppath)));
3261
3262 pgstat_report_wait_start(WAIT_EVENT_WAL_INIT_WRITE);
3263 save_errno = 0;
3264 if (wal_init_zero)
3265 {
3266 ssize_t rc;
3267
3268 /*
3269 * Zero-fill the file. With this setting, we do this the hard way to
3270 * ensure that all the file space has really been allocated. On
3271 * platforms that allow "holes" in files, just seeking to the end
3272 * doesn't allocate intermediate space. This way, we know that we
3273 * have all the space and (after the fsync below) that all the
3274 * indirect blocks are down on disk. Therefore, fdatasync(2) or
3275 * O_DSYNC will be sufficient to sync future writes to the log file.
3276 */
3278
3279 if (rc < 0)
3280 save_errno = errno;
3281 }
3282 else
3283 {
3284 /*
3285 * Otherwise, seeking to the end and writing a solitary byte is
3286 * enough.
3287 */
3288 errno = 0;
3289 if (pg_pwrite(fd, "\0", 1, wal_segment_size - 1) != 1)
3290 {
3291 /* if write didn't set errno, assume no disk space */
3292 save_errno = errno ? errno : ENOSPC;
3293 }
3294 }
3296
3297 if (save_errno)
3298 {
3299 /*
3300 * If we fail to make the file, delete it to release disk space
3301 */
3302 unlink(tmppath);
3303
3304 close(fd);
3305
3306 errno = save_errno;
3307
3308 ereport(ERROR,
3310 errmsg("could not write to file \"%s\": %m", tmppath)));
3311 }
3312
3313 pgstat_report_wait_start(WAIT_EVENT_WAL_INIT_SYNC);
3314 if (pg_fsync(fd) != 0)
3315 {
3316 save_errno = errno;
3317 close(fd);
3318 errno = save_errno;
3319 ereport(ERROR,
3321 errmsg("could not fsync file \"%s\": %m", tmppath)));
3322 }
3324
3325 if (close(fd) != 0)
3326 ereport(ERROR,
3328 errmsg("could not close file \"%s\": %m", tmppath)));
3329
3330 /*
3331 * Now move the segment into place with its final name. Cope with
3332 * possibility that someone else has created the file while we were
3333 * filling ours: if so, use ours to pre-create a future log segment.
3334 */
3335 installed_segno = logsegno;
3336
3337 /*
3338 * XXX: What should we use as max_segno? We used to use XLOGfileslop when
3339 * that was a constant, but that was always a bit dubious: normally, at a
3340 * checkpoint, XLOGfileslop was the offset from the checkpoint record, but
3341 * here, it was the offset from the insert location. We can't do the
3342 * normal XLOGfileslop calculation here because we don't have access to
3343 * the prior checkpoint's redo location. So somewhat arbitrarily, just use
3344 * CheckPointSegments.
3345 */
3346 max_segno = logsegno + CheckPointSegments;
3347 if (InstallXLogFileSegment(&installed_segno, tmppath, true, max_segno,
3348 logtli))
3349 {
3350 *added = true;
3351 elog(DEBUG2, "done creating and filling new WAL file");
3352 }
3353 else
3354 {
3355 /*
3356 * No need for any more future segments, or InstallXLogFileSegment()
3357 * failed to rename the file into place. If the rename failed, a
3358 * caller opening the file may fail.
3359 */
3360 unlink(tmppath);
3361 elog(DEBUG2, "abandoned new WAL file");
3362 }
3363
3364 return -1;
3365}
#define IO_DIRECT_WAL_INIT
Definition: fd.h:56
ssize_t pg_pwrite_zeros(int fd, size_t size, off_t offset)
Definition: file_utils.c:688
#define pg_pwrite
Definition: port.h:226
bool wal_init_zero
Definition: xlog.c:127

References Assert, BasicOpenFile(), CheckPointSegments, close, DEBUG2, elog, ereport, errcode_for_file_access(), errmsg(), ERROR, fd(), get_sync_bit(), InstallXLogFileSegment(), io_direct_flags, IO_DIRECT_WAL_INIT, MAXPGPATH, O_CLOEXEC, PG_BINARY, pg_fsync(), PG_O_DIRECT, pg_pwrite, pg_pwrite_zeros(), pgstat_report_wait_end(), pgstat_report_wait_start(), snprintf, wal_init_zero, wal_segment_size, wal_sync_method, XLOGDIR, and XLogFilePath().

Referenced by PreallocXlogFiles(), and XLogFileInit().

◆ XLogFileOpen()

int XLogFileOpen ( XLogSegNo  segno,
TimeLineID  tli 
)

Definition at line 3618 of file xlog.c.

3619{
3620 char path[MAXPGPATH];
3621 int fd;
3622
3623 XLogFilePath(path, tli, segno, wal_segment_size);
3624
3625 fd = BasicOpenFile(path, O_RDWR | PG_BINARY | O_CLOEXEC |
3627 if (fd < 0)
3628 ereport(PANIC,
3630 errmsg("could not open file \"%s\": %m", path)));
3631
3632 return fd;
3633}

References BasicOpenFile(), ereport, errcode_for_file_access(), errmsg(), fd(), get_sync_bit(), MAXPGPATH, O_CLOEXEC, PANIC, PG_BINARY, wal_segment_size, wal_sync_method, and XLogFilePath().

Referenced by XLogWrite().

◆ XLOGfileslop()

static XLogSegNo XLOGfileslop ( XLogRecPtr  lastredoptr)
static

Definition at line 2240 of file xlog.c.

2241{
2242 XLogSegNo minSegNo;
2243 XLogSegNo maxSegNo;
2244 double distance;
2245 XLogSegNo recycleSegNo;
2246
2247 /*
2248 * Calculate the segment numbers that min_wal_size_mb and max_wal_size_mb
2249 * correspond to. Always recycle enough segments to meet the minimum, and
2250 * remove enough segments to stay below the maximum.
2251 */
2252 minSegNo = lastredoptr / wal_segment_size +
2254 maxSegNo = lastredoptr / wal_segment_size +
2256
2257 /*
2258 * Between those limits, recycle enough segments to get us through to the
2259 * estimated end of next checkpoint.
2260 *
2261 * To estimate where the next checkpoint will finish, assume that the
2262 * system runs steadily consuming CheckPointDistanceEstimate bytes between
2263 * every checkpoint.
2264 */
2266 /* add 10% for good measure. */
2267 distance *= 1.10;
2268
2269 recycleSegNo = (XLogSegNo) ceil(((double) lastredoptr + distance) /
2271
2272 if (recycleSegNo < minSegNo)
2273 recycleSegNo = minSegNo;
2274 if (recycleSegNo > maxSegNo)
2275 recycleSegNo = maxSegNo;
2276
2277 return recycleSegNo;
2278}

References CheckPointCompletionTarget, CheckPointDistanceEstimate, ConvertToXSegs, max_wal_size_mb, min_wal_size_mb, and wal_segment_size.

Referenced by RemoveOldXlogFiles().

◆ XLogFlush()

void XLogFlush ( XLogRecPtr  record)

Definition at line 2802 of file xlog.c.

2803{
2804 XLogRecPtr WriteRqstPtr;
2805 XLogwrtRqst WriteRqst;
2806 TimeLineID insertTLI = XLogCtl->InsertTimeLineID;
2807
2808 /*
2809 * During REDO, we are reading not writing WAL. Therefore, instead of
2810 * trying to flush the WAL, we should update minRecoveryPoint instead. We
2811 * test XLogInsertAllowed(), not InRecovery, because we need checkpointer
2812 * to act this way too, and because when it tries to write the
2813 * end-of-recovery checkpoint, it should indeed flush.
2814 */
2815 if (!XLogInsertAllowed())
2816 {
2817 UpdateMinRecoveryPoint(record, false);
2818 return;
2819 }
2820
2821 /* Quick exit if already known flushed */
2822 if (record <= LogwrtResult.Flush)
2823 return;
2824
2825#ifdef WAL_DEBUG
2826 if (XLOG_DEBUG)
2827 elog(LOG, "xlog flush request %X/%X; write %X/%X; flush %X/%X",
2828 LSN_FORMAT_ARGS(record),
2831#endif
2832
2834
2835 /*
2836 * Since fsync is usually a horribly expensive operation, we try to
2837 * piggyback as much data as we can on each fsync: if we see any more data
2838 * entered into the xlog buffer, we'll write and fsync that too, so that
2839 * the final value of LogwrtResult.Flush is as large as possible. This
2840 * gives us some chance of avoiding another fsync immediately after.
2841 */
2842
2843 /* initialize to given target; may increase below */
2844 WriteRqstPtr = record;
2845
2846 /*
2847 * Now wait until we get the write lock, or someone else does the flush
2848 * for us.
2849 */
2850 for (;;)
2851 {
2852 XLogRecPtr insertpos;
2853
2854 /* done already? */
2856 if (record <= LogwrtResult.Flush)
2857 break;
2858
2859 /*
2860 * Before actually performing the write, wait for all in-flight
2861 * insertions to the pages we're about to write to finish.
2862 */
2864 if (WriteRqstPtr < XLogCtl->LogwrtRqst.Write)
2865 WriteRqstPtr = XLogCtl->LogwrtRqst.Write;
2867 insertpos = WaitXLogInsertionsToFinish(WriteRqstPtr);
2868
2869 /*
2870 * Try to get the write lock. If we can't get it immediately, wait
2871 * until it's released, and recheck if we still need to do the flush
2872 * or if the backend that held the lock did it for us already. This
2873 * helps to maintain a good rate of group committing when the system
2874 * is bottlenecked by the speed of fsyncing.
2875 */
2876 if (!LWLockAcquireOrWait(WALWriteLock, LW_EXCLUSIVE))
2877 {
2878 /*
2879 * The lock is now free, but we didn't acquire it yet. Before we
2880 * do, loop back to check if someone else flushed the record for
2881 * us already.
2882 */
2883 continue;
2884 }
2885
2886 /* Got the lock; recheck whether request is satisfied */
2888 if (record <= LogwrtResult.Flush)
2889 {
2890 LWLockRelease(WALWriteLock);
2891 break;
2892 }
2893
2894 /*
2895 * Sleep before flush! By adding a delay here, we may give further
2896 * backends the opportunity to join the backlog of group commit
2897 * followers; this can significantly improve transaction throughput,
2898 * at the risk of increasing transaction latency.
2899 *
2900 * We do not sleep if enableFsync is not turned on, nor if there are
2901 * fewer than CommitSiblings other backends with active transactions.
2902 */
2903 if (CommitDelay > 0 && enableFsync &&
2905 {
2907
2908 /*
2909 * Re-check how far we can now flush the WAL. It's generally not
2910 * safe to call WaitXLogInsertionsToFinish while holding
2911 * WALWriteLock, because an in-progress insertion might need to
2912 * also grab WALWriteLock to make progress. But we know that all
2913 * the insertions up to insertpos have already finished, because
2914 * that's what the earlier WaitXLogInsertionsToFinish() returned.
2915 * We're only calling it again to allow insertpos to be moved
2916 * further forward, not to actually wait for anyone.
2917 */
2918 insertpos = WaitXLogInsertionsToFinish(insertpos);
2919 }
2920
2921 /* try to write/flush later additions to XLOG as well */
2922 WriteRqst.Write = insertpos;
2923 WriteRqst.Flush = insertpos;
2924
2925 XLogWrite(WriteRqst, insertTLI, false);
2926
2927 LWLockRelease(WALWriteLock);
2928 /* done */
2929 break;
2930 }
2931
2933
2934 /* wake up walsenders now that we've released heavily contended locks */
2936
2937 /*
2938 * If we still haven't flushed to the request point then we have a
2939 * problem; most likely, the requested flush point is past end of XLOG.
2940 * This has been seen to occur when a disk page has a corrupted LSN.
2941 *
2942 * Formerly we treated this as a PANIC condition, but that hurts the
2943 * system's robustness rather than helping it: we do not want to take down
2944 * the whole system due to corruption on one data page. In particular, if
2945 * the bad page is encountered again during recovery then we would be
2946 * unable to restart the database at all! (This scenario actually
2947 * happened in the field several times with 7.1 releases.) As of 8.4, bad
2948 * LSNs encountered during recovery are UpdateMinRecoveryPoint's problem;
2949 * the only time we can reach here during recovery is while flushing the
2950 * end-of-recovery checkpoint record, and we don't expect that to have a
2951 * bad LSN.
2952 *
2953 * Note that for calls from xact.c, the ERROR will be promoted to PANIC
2954 * since xact.c calls this routine inside a critical section. However,
2955 * calls from bufmgr.c are not within critical sections and so we will not
2956 * force a restart for a bad LSN on a data page.
2957 */
2958 if (LogwrtResult.Flush < record)
2959 elog(ERROR,
2960 "xlog flush request %X/%X is not satisfied --- flushed only to %X/%X",
2961 LSN_FORMAT_ARGS(record),
2963}
bool LWLockAcquireOrWait(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1396
bool MinimumActiveBackends(int min)
Definition: procarray.c:3546
int CommitDelay
Definition: xlog.c:132
int CommitSiblings
Definition: xlog.c:133
bool XLogInsertAllowed(void)
Definition: xlog.c:6389

References CommitDelay, CommitSiblings, elog, enableFsync, END_CRIT_SECTION, ERROR, XLogwrtRqst::Flush, XLogwrtResult::Flush, XLogCtlData::info_lck, XLogCtlData::InsertTimeLineID, LOG, LogwrtResult, XLogCtlData::LogwrtRqst, LSN_FORMAT_ARGS, LW_EXCLUSIVE, LWLockAcquireOrWait(), LWLockRelease(), MinimumActiveBackends(), pg_usleep(), RecoveryInProgress(), RefreshXLogWriteResult, SpinLockAcquire, SpinLockRelease, START_CRIT_SECTION, UpdateMinRecoveryPoint(), WaitXLogInsertionsToFinish(), WalSndWakeupProcessRequests(), XLogwrtRqst::Write, XLogwrtResult::Write, XLogCtl, XLogInsertAllowed(), and XLogWrite().

Referenced by CheckPointReplicationOrigin(), CreateCheckPoint(), CreateEndOfRecoveryRecord(), CreateOverwriteContrecordRecord(), dropdb(), EndPrepare(), FlushBuffer(), LogLogicalMessage(), pg_attribute_noreturn(), pg_truncate_visibility_map(), RecordTransactionAbortPrepared(), RecordTransactionCommit(), RecordTransactionCommitPrepared(), RelationTruncate(), ReplicationSlotReserveWal(), replorigin_get_progress(), replorigin_session_get_progress(), SlruPhysicalWritePage(), smgr_redo(), write_relmap_file(), WriteMTruncateXlogRec(), WriteTruncateXlogRec(), xact_redo_abort(), xact_redo_commit(), XLogInsertRecord(), and XLogReportParameters().

◆ XLogGetLastRemovedSegno()

XLogSegNo XLogGetLastRemovedSegno ( void  )

Definition at line 3758 of file xlog.c.

3759{
3760 XLogSegNo lastRemovedSegNo;
3761
3763 lastRemovedSegNo = XLogCtl->lastRemovedSegNo;
3765
3766 return lastRemovedSegNo;
3767}

References XLogCtlData::info_lck, XLogCtlData::lastRemovedSegNo, SpinLockAcquire, SpinLockRelease, and XLogCtl.

Referenced by copy_replication_slot(), GetWALAvailability(), ReplicationSlotReserveWal(), and reserve_wal_for_local_slot().

◆ XLogGetOldestSegno()

XLogSegNo XLogGetOldestSegno ( TimeLineID  tli)

Definition at line 3774 of file xlog.c.

3775{
3776 DIR *xldir;
3777 struct dirent *xlde;
3778 XLogSegNo oldest_segno = 0;
3779
3780 xldir = AllocateDir(XLOGDIR);
3781 while ((xlde = ReadDir(xldir, XLOGDIR)) != NULL)
3782 {
3783 TimeLineID file_tli;
3784 XLogSegNo file_segno;
3785
3786 /* Ignore files that are not XLOG segments. */
3787 if (!IsXLogFileName(xlde->d_name))
3788 continue;
3789
3790 /* Parse filename to get TLI and segno. */
3791 XLogFromFileName(xlde->d_name, &file_tli, &file_segno,
3793
3794 /* Ignore anything that's not from the TLI of interest. */
3795 if (tli != file_tli)
3796 continue;
3797
3798 /* If it's the oldest so far, update oldest_segno. */
3799 if (oldest_segno == 0 || file_segno < oldest_segno)
3800 oldest_segno = file_segno;
3801 }
3802
3803 FreeDir(xldir);
3804 return oldest_segno;
3805}

References AllocateDir(), dirent::d_name, FreeDir(), IsXLogFileName(), ReadDir(), wal_segment_size, XLOGDIR, and XLogFromFileName().

Referenced by GetOldestUnsummarizedLSN(), MaybeRemoveOldWalSummaries(), and reserve_wal_for_local_slot().

◆ XLogGetReplicationSlotMinimumLSN()

static XLogRecPtr XLogGetReplicationSlotMinimumLSN ( void  )
static

Definition at line 2701 of file xlog.c.

2702{
2703 XLogRecPtr retval;
2704
2708
2709 return retval;
2710}
XLogRecPtr replicationSlotMinLSN
Definition: xlog.c:459

References XLogCtlData::info_lck, XLogCtlData::replicationSlotMinLSN, SpinLockAcquire, SpinLockRelease, and XLogCtl.

Referenced by KeepLogSeg().

◆ XLogInitNewTimeline()

static void XLogInitNewTimeline ( TimeLineID  endTLI,
XLogRecPtr  endOfLog,
TimeLineID  newTLI 
)
static

Definition at line 5214 of file xlog.c.

5215{
5216 char xlogfname[MAXFNAMELEN];
5217 XLogSegNo endLogSegNo;
5218 XLogSegNo startLogSegNo;
5219
5220 /* we always switch to a new timeline after archive recovery */
5221 Assert(endTLI != newTLI);
5222
5223 /*
5224 * Update min recovery point one last time.
5225 */
5227
5228 /*
5229 * Calculate the last segment on the old timeline, and the first segment
5230 * on the new timeline. If the switch happens in the middle of a segment,
5231 * they are the same, but if the switch happens exactly at a segment
5232 * boundary, startLogSegNo will be endLogSegNo + 1.
5233 */
5234 XLByteToPrevSeg(endOfLog, endLogSegNo, wal_segment_size);
5235 XLByteToSeg(endOfLog, startLogSegNo, wal_segment_size);
5236
5237 /*
5238 * Initialize the starting WAL segment for the new timeline. If the switch
5239 * happens in the middle of a segment, copy data from the last WAL segment
5240 * of the old timeline up to the switch point, to the starting WAL segment
5241 * on the new timeline.
5242 */
5243 if (endLogSegNo == startLogSegNo)
5244 {
5245 /*
5246 * Make a copy of the file on the new timeline.
5247 *
5248 * Writing WAL isn't allowed yet, so there are no locking
5249 * considerations. But we should be just as tense as XLogFileInit to
5250 * avoid emplacing a bogus file.
5251 */
5252 XLogFileCopy(newTLI, endLogSegNo, endTLI, endLogSegNo,
5254 }
5255 else
5256 {
5257 /*
5258 * The switch happened at a segment boundary, so just create the next
5259 * segment on the new timeline.
5260 */
5261 int fd;
5262
5263 fd = XLogFileInit(startLogSegNo, newTLI);
5264
5265 if (close(fd) != 0)
5266 {
5267 int save_errno = errno;
5268
5269 XLogFileName(xlogfname, newTLI, startLogSegNo, wal_segment_size);
5270 errno = save_errno;
5271 ereport(ERROR,
5273 errmsg("could not close file \"%s\": %m", xlogfname)));
5274 }
5275 }
5276
5277 /*
5278 * Let's just make real sure there are not .ready or .done flags posted
5279 * for the new segment.
5280 */
5281 XLogFileName(xlogfname, newTLI, startLogSegNo, wal_segment_size);
5282 XLogArchiveCleanup(xlogfname);
5283}
static void XLogFileCopy(TimeLineID destTLI, XLogSegNo destsegno, TimeLineID srcTLI, XLogSegNo srcsegno, int upto)
Definition: xlog.c:3418

References Assert, close, ereport, errcode_for_file_access(), errmsg(), ERROR, fd(), InvalidXLogRecPtr, MAXFNAMELEN, UpdateMinRecoveryPoint(), wal_segment_size, XLByteToPrevSeg, XLByteToSeg, XLogArchiveCleanup(), XLogFileCopy(), XLogFileInit(), XLogFileName(), and XLogSegmentOffset.

Referenced by StartupXLOG().

◆ XLogInsertAllowed()

bool XLogInsertAllowed ( void  )

Definition at line 6389 of file xlog.c.

6390{
6391 /*
6392 * If value is "unconditionally true" or "unconditionally false", just
6393 * return it. This provides the normal fast path once recovery is known
6394 * done.
6395 */
6396 if (LocalXLogInsertAllowed >= 0)
6397 return (bool) LocalXLogInsertAllowed;
6398
6399 /*
6400 * Else, must check to see if we're still in recovery.
6401 */
6402 if (RecoveryInProgress())
6403 return false;
6404
6405 /*
6406 * On exit from recovery, reset to "unconditionally true", since there is
6407 * no need to keep checking.
6408 */
6410 return true;
6411}

References LocalXLogInsertAllowed, and RecoveryInProgress().

Referenced by XLogBeginInsert(), XLogFlush(), and XLogInsertRecord().

◆ XLogInsertRecord()

XLogRecPtr XLogInsertRecord ( XLogRecData rdata,
XLogRecPtr  fpw_lsn,
uint8  flags,
int  num_fpi,
bool  topxid_included 
)

Definition at line 748 of file xlog.c.

753{
755 pg_crc32c rdata_crc;
756 bool inserted;
757 XLogRecord *rechdr = (XLogRecord *) rdata->data;
758 uint8 info = rechdr->xl_info & ~XLR_INFO_MASK;
760 XLogRecPtr StartPos;
761 XLogRecPtr EndPos;
762 bool prevDoPageWrites = doPageWrites;
763 TimeLineID insertTLI;
764
765 /* Does this record type require special handling? */
766 if (unlikely(rechdr->xl_rmid == RM_XLOG_ID))
767 {
768 if (info == XLOG_SWITCH)
770 else if (info == XLOG_CHECKPOINT_REDO)
772 }
773
774 /* we assume that all of the record header is in the first chunk */
775 Assert(rdata->len >= SizeOfXLogRecord);
776
777 /* cross-check on whether we should be here or not */
778 if (!XLogInsertAllowed())
779 elog(ERROR, "cannot make new WAL entries during recovery");
780
781 /*
782 * Given that we're not in recovery, InsertTimeLineID is set and can't
783 * change, so we can read it without a lock.
784 */
785 insertTLI = XLogCtl->InsertTimeLineID;
786
787 /*----------
788 *
789 * We have now done all the preparatory work we can without holding a
790 * lock or modifying shared state. From here on, inserting the new WAL
791 * record to the shared WAL buffer cache is a two-step process:
792 *
793 * 1. Reserve the right amount of space from the WAL. The current head of
794 * reserved space is kept in Insert->CurrBytePos, and is protected by
795 * insertpos_lck.
796 *
797 * 2. Copy the record to the reserved WAL space. This involves finding the
798 * correct WAL buffer containing the reserved space, and copying the
799 * record in place. This can be done concurrently in multiple processes.
800 *
801 * To keep track of which insertions are still in-progress, each concurrent
802 * inserter acquires an insertion lock. In addition to just indicating that
803 * an insertion is in progress, the lock tells others how far the inserter
804 * has progressed. There is a small fixed number of insertion locks,
805 * determined by NUM_XLOGINSERT_LOCKS. When an inserter crosses a page
806 * boundary, it updates the value stored in the lock to the how far it has
807 * inserted, to allow the previous buffer to be flushed.
808 *
809 * Holding onto an insertion lock also protects RedoRecPtr and
810 * fullPageWrites from changing until the insertion is finished.
811 *
812 * Step 2 can usually be done completely in parallel. If the required WAL
813 * page is not initialized yet, you have to grab WALBufMappingLock to
814 * initialize it, but the WAL writer tries to do that ahead of insertions
815 * to avoid that from happening in the critical path.
816 *
817 *----------
818 */
820
821 if (likely(class == WALINSERT_NORMAL))
822 {
824
825 /*
826 * Check to see if my copy of RedoRecPtr is out of date. If so, may
827 * have to go back and have the caller recompute everything. This can
828 * only happen just after a checkpoint, so it's better to be slow in
829 * this case and fast otherwise.
830 *
831 * Also check to see if fullPageWrites was just turned on or there's a
832 * running backup (which forces full-page writes); if we weren't
833 * already doing full-page writes then go back and recompute.
834 *
835 * If we aren't doing full-page writes then RedoRecPtr doesn't
836 * actually affect the contents of the XLOG record, so we'll update
837 * our local copy but not force a recomputation. (If doPageWrites was
838 * just turned off, we could recompute the record without full pages,
839 * but we choose not to bother.)
840 */
841 if (RedoRecPtr != Insert->RedoRecPtr)
842 {
843 Assert(RedoRecPtr < Insert->RedoRecPtr);
844 RedoRecPtr = Insert->RedoRecPtr;
845 }
846 doPageWrites = (Insert->fullPageWrites || Insert->runningBackups > 0);
847
848 if (doPageWrites &&
849 (!prevDoPageWrites ||
850 (fpw_lsn != InvalidXLogRecPtr && fpw_lsn <= RedoRecPtr)))
851 {
852 /*
853 * Oops, some buffer now needs to be backed up that the caller
854 * didn't back up. Start over.
855 */
858 return InvalidXLogRecPtr;
859 }
860
861 /*
862 * Reserve space for the record in the WAL. This also sets the xl_prev
863 * pointer.
864 */
865 ReserveXLogInsertLocation(rechdr->xl_tot_len, &StartPos, &EndPos,
866 &rechdr->xl_prev);
867
868 /* Normal records are always inserted. */
869 inserted = true;
870 }
871 else if (class == WALINSERT_SPECIAL_SWITCH)
872 {
873 /*
874 * In order to insert an XLOG_SWITCH record, we need to hold all of
875 * the WAL insertion locks, not just one, so that no one else can
876 * begin inserting a record until we've figured out how much space
877 * remains in the current WAL segment and claimed all of it.
878 *
879 * Nonetheless, this case is simpler than the normal cases handled
880 * below, which must check for changes in doPageWrites and RedoRecPtr.
881 * Those checks are only needed for records that can contain buffer
882 * references, and an XLOG_SWITCH record never does.
883 */
884 Assert(fpw_lsn == InvalidXLogRecPtr);
886 inserted = ReserveXLogSwitch(&StartPos, &EndPos, &rechdr->xl_prev);
887 }
888 else
889 {
891
892 /*
893 * We need to update both the local and shared copies of RedoRecPtr,
894 * which means that we need to hold all the WAL insertion locks.
895 * However, there can't be any buffer references, so as above, we need
896 * not check RedoRecPtr before inserting the record; we just need to
897 * update it afterwards.
898 */
899 Assert(fpw_lsn == InvalidXLogRecPtr);
901 ReserveXLogInsertLocation(rechdr->xl_tot_len, &StartPos, &EndPos,
902 &rechdr->xl_prev);
903 RedoRecPtr = Insert->RedoRecPtr = StartPos;
904 inserted = true;
905 }
906
907 if (inserted)
908 {
909 /*
910 * Now that xl_prev has been filled in, calculate CRC of the record
911 * header.
912 */
913 rdata_crc = rechdr->xl_crc;
914 COMP_CRC32C(rdata_crc, rechdr, offsetof(XLogRecord, xl_crc));
915 FIN_CRC32C(rdata_crc);
916 rechdr->xl_crc = rdata_crc;
917
918 /*
919 * All the record data, including the header, is now ready to be
920 * inserted. Copy the record in the space reserved.
921 */
923 class == WALINSERT_SPECIAL_SWITCH, rdata,
924 StartPos, EndPos, insertTLI);
925
926 /*
927 * Unless record is flagged as not important, update LSN of last
928 * important record in the current slot. When holding all locks, just
929 * update the first one.
930 */
931 if ((flags & XLOG_MARK_UNIMPORTANT) == 0)
932 {
933 int lockno = holdingAllLocks ? 0 : MyLockNo;
934
935 WALInsertLocks[lockno].l.lastImportantAt = StartPos;
936 }
937 }
938 else
939 {
940 /*
941 * This was an xlog-switch record, but the current insert location was
942 * already exactly at the beginning of a segment, so there was no need
943 * to do anything.
944 */
945 }
946
947 /*
948 * Done! Let others know that we're finished.
949 */
951
953
955
956 /*
957 * Mark top transaction id is logged (if needed) so that we should not try
958 * to log it again with the next WAL record in the current subtransaction.
959 */
960 if (topxid_included)
962
963 /*
964 * Update shared LogwrtRqst.Write, if we crossed page boundary.
965 */
966 if (StartPos / XLOG_BLCKSZ != EndPos / XLOG_BLCKSZ)
967 {
969 /* advance global request to include new block(s) */
970 if (XLogCtl->LogwrtRqst.Write < EndPos)
971 XLogCtl->LogwrtRqst.Write = EndPos;
974 }
975
976 /*
977 * If this was an XLOG_SWITCH record, flush the record and the empty
978 * padding space that fills the rest of the segment, and perform
979 * end-of-segment actions (eg, notifying archiver).
980 */
981 if (class == WALINSERT_SPECIAL_SWITCH)
982 {
983 TRACE_POSTGRESQL_WAL_SWITCH();
984 XLogFlush(EndPos);
985
986 /*
987 * Even though we reserved the rest of the segment for us, which is
988 * reflected in EndPos, we return a pointer to just the end of the
989 * xlog-switch record.
990 */
991 if (inserted)
992 {
993 EndPos = StartPos + SizeOfXLogRecord;
994 if (StartPos / XLOG_BLCKSZ != EndPos / XLOG_BLCKSZ)
995 {
996 uint64 offset = XLogSegmentOffset(EndPos, wal_segment_size);
997
998 if (offset == EndPos % XLOG_BLCKSZ)
999 EndPos += SizeOfXLogLongPHD;
1000 else
1001 EndPos += SizeOfXLogShortPHD;
1002 }
1003 }
1004 }
1005
1006#ifdef WAL_DEBUG
1007 if (XLOG_DEBUG)
1008 {
1009 static XLogReaderState *debug_reader = NULL;
1010 XLogRecord *record;
1011 DecodedXLogRecord *decoded;
1013 StringInfoData recordBuf;
1014 char *errormsg = NULL;
1015 MemoryContext oldCxt;
1016
1017 oldCxt = MemoryContextSwitchTo(walDebugCxt);
1018
1020 appendStringInfo(&buf, "INSERT @ %X/%X: ", LSN_FORMAT_ARGS(EndPos));
1021
1022 /*
1023 * We have to piece together the WAL record data from the XLogRecData
1024 * entries, so that we can pass it to the rm_desc function as one
1025 * contiguous chunk.
1026 */
1027 initStringInfo(&recordBuf);
1028 for (; rdata != NULL; rdata = rdata->next)
1029 appendBinaryStringInfo(&recordBuf, rdata->data, rdata->len);
1030
1031 /* We also need temporary space to decode the record. */
1032 record = (XLogRecord *) recordBuf.data;
1033 decoded = (DecodedXLogRecord *)
1035
1036 if (!debug_reader)
1037 debug_reader = XLogReaderAllocate(wal_segment_size, NULL,
1038 XL_ROUTINE(.page_read = NULL,
1039 .segment_open = NULL,
1040 .segment_close = NULL),
1041 NULL);
1042 if (!debug_reader)
1043 {
1044 appendStringInfoString(&buf, "error decoding record: out of memory while allocating a WAL reading processor");
1045 }
1046 else if (!DecodeXLogRecord(debug_reader,
1047 decoded,
1048 record,
1049 EndPos,
1050 &errormsg))
1051 {
1052 appendStringInfo(&buf, "error decoding record: %s",
1053 errormsg ? errormsg : "no error message");
1054 }
1055 else
1056 {
1057 appendStringInfoString(&buf, " - ");
1058
1059 debug_reader->record = decoded;
1060 xlog_outdesc(&buf, debug_reader);
1061 debug_reader->record = NULL;
1062 }
1063 elog(LOG, "%s", buf.data);
1064
1065 pfree(decoded);
1066 pfree(buf.data);
1067 pfree(recordBuf.data);
1068 MemoryContextSwitchTo(oldCxt);
1069 }
1070#endif
1071
1072 /*
1073 * Update our global variables
1074 */
1075 ProcLastRecPtr = StartPos;
1076 XactLastRecEnd = EndPos;
1077
1078 /* Report WAL traffic to the instrumentation. */
1079 if (inserted)
1080 {
1081 pgWalUsage.wal_bytes += rechdr->xl_tot_len;
1083 pgWalUsage.wal_fpi += num_fpi;
1084 }
1085
1086 return EndPos;
1087}
#define likely(x)
Definition: c.h:329
#define unlikely(x)
Definition: c.h:330
WalUsage pgWalUsage
Definition: instrument.c:22
if(TABLE==NULL||TABLE_index==NULL)
Definition: isn.c:76
MemoryContextSwitchTo(old_ctx)
void appendBinaryStringInfo(StringInfo str, const void *data, int datalen)
Definition: stringinfo.c:230
void appendStringInfoString(StringInfo str, const char *s)
Definition: stringinfo.c:179
uint64 wal_bytes
Definition: instrument.h:55
int64 wal_fpi
Definition: instrument.h:54
int64 wal_records
Definition: instrument.h:53
DecodedXLogRecord * record
Definition: xlogreader.h:236
pg_crc32c xl_crc
Definition: xlogrecord.h:49
void MarkSubxactTopXidLogged(void)
Definition: xact.c:590
void MarkCurrentTransactionIdLoggedIfAny(void)
Definition: xact.c:540
XLogRecPtr XactLastRecEnd
Definition: xlog.c:254
static void CopyXLogRecordToWAL(int write_len, bool isLogSwitch, XLogRecData *rdata, XLogRecPtr StartPos, XLogRecPtr EndPos, TimeLineID tli)
Definition: xlog.c:1225
static void ReserveXLogInsertLocation(int size, XLogRecPtr *StartPos, XLogRecPtr *EndPos, XLogRecPtr *PrevPtr)
Definition: xlog.c:1108
static bool ReserveXLogSwitch(XLogRecPtr *StartPos, XLogRecPtr *EndPos, XLogRecPtr *PrevPtr)
Definition: xlog.c:1164
XLogReaderState * XLogReaderAllocate(int wal_segment_size, const char *waldir, XLogReaderRoutine *routine, void *private_data)
Definition: xlogreader.c:106
bool DecodeXLogRecord(XLogReaderState *state, DecodedXLogRecord *decoded, XLogRecord *record, XLogRecPtr lsn, char **errormsg)
Definition: xlogreader.c:1662
size_t DecodeXLogRecordRequiredSpace(size_t xl_tot_len)
Definition: xlogreader.c:1629
#define XL_ROUTINE(...)
Definition: xlogreader.h:117
#define XLR_INFO_MASK
Definition: xlogrecord.h:62
void xlog_outdesc(StringInfo buf, XLogReaderState *record)

References appendBinaryStringInfo(), appendStringInfo(), appendStringInfoString(), Assert, buf, COMP_CRC32C, CopyXLogRecordToWAL(), XLogRecData::data, StringInfoData::data, DecodeXLogRecord(), DecodeXLogRecordRequiredSpace(), doPageWrites, elog, END_CRIT_SECTION, ERROR, FIN_CRC32C, holdingAllLocks, if(), XLogCtlData::info_lck, initStringInfo(), XLogCtlData::Insert, Insert(), XLogCtlData::InsertTimeLineID, InvalidXLogRecPtr, WALInsertLockPadded::l, WALInsertLock::lastImportantAt, XLogRecData::len, likely, LOG, LogwrtResult, XLogCtlData::LogwrtRqst, LSN_FORMAT_ARGS, MarkCurrentTransactionIdLoggedIfAny(), MarkSubxactTopXidLogged(), MemoryContextSwitchTo(), MyLockNo, XLogRecData::next, palloc(), pfree(), pgWalUsage, ProcLastRecPtr, XLogReaderState::record, RedoRecPtr, RefreshXLogWriteResult, ReserveXLogInsertLocation(), ReserveXLogSwitch(), SizeOfXLogLongPHD, SizeOfXLogRecord, SizeOfXLogShortPHD, SpinLockAcquire, SpinLockRelease, START_CRIT_SECTION, unlikely, WalUsage::wal_bytes, WalUsage::wal_fpi, WalUsage::wal_records, wal_segment_size, WALINSERT_NORMAL, WALINSERT_SPECIAL_CHECKPOINT, WALINSERT_SPECIAL_SWITCH, WALInsertLockAcquire(), WALInsertLockAcquireExclusive(), WALInsertLockRelease(), WALInsertLocks, XLogwrtRqst::Write, XactLastRecEnd, XLogRecord::xl_crc, XLogRecord::xl_info, XLogRecord::xl_prev, XLogRecord::xl_rmid, XL_ROUTINE, XLogRecord::xl_tot_len, XLOG_CHECKPOINT_REDO, XLOG_MARK_UNIMPORTANT, xlog_outdesc(), XLOG_SWITCH, XLogCtl, XLogFlush(), XLogInsertAllowed(), XLogReaderAllocate(), XLogSegmentOffset, and XLR_INFO_MASK.

Referenced by XLogInsert().

◆ XLogNeedsFlush()

bool XLogNeedsFlush ( XLogRecPtr  record)

Definition at line 3133 of file xlog.c.

3134{
3135 /*
3136 * During recovery, we don't flush WAL but update minRecoveryPoint
3137 * instead. So "needs flush" is taken to mean whether minRecoveryPoint
3138 * would need to be updated.
3139 */
3140 if (RecoveryInProgress())
3141 {
3142 /*
3143 * An invalid minRecoveryPoint means that we need to recover all the
3144 * WAL, i.e., we're doing crash recovery. We never modify the control
3145 * file's value in that case, so we can short-circuit future checks
3146 * here too. This triggers a quick exit path for the startup process,
3147 * which cannot update its local copy of minRecoveryPoint as long as
3148 * it has not replayed all WAL available when doing crash recovery.
3149 */
3151 updateMinRecoveryPoint = false;
3152
3153 /* Quick exit if already known to be updated or cannot be updated */
3155 return false;
3156
3157 /*
3158 * Update local copy of minRecoveryPoint. But if the lock is busy,
3159 * just return a conservative guess.
3160 */
3161 if (!LWLockConditionalAcquire(ControlFileLock, LW_SHARED))
3162 return true;
3165 LWLockRelease(ControlFileLock);
3166
3167 /*
3168 * Check minRecoveryPoint for any other process than the startup
3169 * process doing crash recovery, which should not update the control
3170 * file value if crash recovery is still running.
3171 */
3173 updateMinRecoveryPoint = false;
3174
3175 /* check again */
3177 return false;
3178 else
3179 return true;
3180 }
3181
3182 /* Quick exit if already known flushed */
3183 if (record <= LogwrtResult.Flush)
3184 return false;
3185
3186 /* read LogwrtResult and update local state */
3188
3189 /* check again */
3190 if (record <= LogwrtResult.Flush)
3191 return false;
3192
3193 return true;
3194}
bool LWLockConditionalAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1339

References ControlFile, XLogwrtResult::Flush, InRecovery, LocalMinRecoveryPoint, LocalMinRecoveryPointTLI, LogwrtResult, LW_SHARED, LWLockConditionalAcquire(), LWLockRelease(), ControlFileData::minRecoveryPoint, ControlFileData::minRecoveryPointTLI, RecoveryInProgress(), RefreshXLogWriteResult, updateMinRecoveryPoint, and XLogRecPtrIsInvalid.

Referenced by GetVictimBuffer(), and SetHintBits().

◆ XLogPutNextOid()

void XLogPutNextOid ( Oid  nextOid)

Definition at line 8023 of file xlog.c.

8024{
8026 XLogRegisterData((char *) (&nextOid), sizeof(Oid));
8027 (void) XLogInsert(RM_XLOG_ID, XLOG_NEXTOID);
8028
8029 /*
8030 * We need not flush the NEXTOID record immediately, because any of the
8031 * just-allocated OIDs could only reach disk as part of a tuple insert or
8032 * update that would have its own XLOG record that must follow the NEXTOID
8033 * record. Therefore, the standard buffer LSN interlock applied to those
8034 * records will ensure no such OID reaches disk before the NEXTOID record
8035 * does.
8036 *
8037 * Note, however, that the above statement only covers state "within" the
8038 * database. When we use a generated OID as a file or directory name, we
8039 * are in a sense violating the basic WAL rule, because that filesystem
8040 * change may reach disk before the NEXTOID WAL record does. The impact
8041 * of this is that if a database crash occurs immediately afterward, we
8042 * might after restart re-generate the same OID and find that it conflicts
8043 * with the leftover file or directory. But since for safety's sake we
8044 * always loop until finding a nonconflicting filename, this poses no real
8045 * problem in practice. See pgsql-hackers discussion 27-Sep-2006.
8046 */
8047}

References XLOG_NEXTOID, XLogBeginInsert(), XLogInsert(), and XLogRegisterData().

Referenced by GetNewObjectId().

◆ XLogRecPtrToBytePos()

static uint64 XLogRecPtrToBytePos ( XLogRecPtr  ptr)
static

Definition at line 1941 of file xlog.c.

1942{
1943 uint64 fullsegs;
1944 uint32 fullpages;
1945 uint32 offset;
1946 uint64 result;
1947
1948 XLByteToSeg(ptr, fullsegs, wal_segment_size);
1949
1950 fullpages = (XLogSegmentOffset(ptr, wal_segment_size)) / XLOG_BLCKSZ;
1951 offset = ptr % XLOG_BLCKSZ;
1952
1953 if (fullpages == 0)
1954 {
1955 result = fullsegs * UsableBytesInSegment;
1956 if (offset > 0)
1957 {
1958 Assert(offset >= SizeOfXLogLongPHD);
1959 result += offset - SizeOfXLogLongPHD;
1960 }
1961 }
1962 else
1963 {
1964 result = fullsegs * UsableBytesInSegment +
1965 (XLOG_BLCKSZ - SizeOfXLogLongPHD) + /* account for first page */
1966 (fullpages - 1) * UsableBytesInPage; /* full pages */
1967 if (offset > 0)
1968 {
1969 Assert(offset >= SizeOfXLogShortPHD);
1970 result += offset - SizeOfXLogShortPHD;
1971 }
1972 }
1973
1974 return result;
1975}

References Assert, SizeOfXLogLongPHD, SizeOfXLogShortPHD, UsableBytesInPage, UsableBytesInSegment, wal_segment_size, XLByteToSeg, and XLogSegmentOffset.

Referenced by ReserveXLogInsertLocation(), ReserveXLogSwitch(), and StartupXLOG().

◆ XLogReportParameters()

static void XLogReportParameters ( void  )
static

Definition at line 8103 of file xlog.c.

8104{
8113 {
8114 /*
8115 * The change in number of backend slots doesn't need to be WAL-logged
8116 * if archiving is not enabled, as you can't start archive recovery
8117 * with wal_level=minimal anyway. We don't really care about the
8118 * values in pg_control either if wal_level=minimal, but seems better
8119 * to keep them up-to-date to avoid confusion.
8120 */
8122 {
8123 xl_parameter_change xlrec;
8124 XLogRecPtr recptr;
8125
8131 xlrec.wal_level = wal_level;
8134
8136 XLogRegisterData((char *) &xlrec, sizeof(xlrec));
8137
8138 recptr = XLogInsert(RM_XLOG_ID, XLOG_PARAMETER_CHANGE);
8139 XLogFlush(recptr);
8140 }
8141
8142 LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
8143
8153
8154 LWLockRelease(ControlFileLock);
8155 }
8156}

References ControlFile, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), max_locks_per_xact, xl_parameter_change::max_locks_per_xact, ControlFileData::max_locks_per_xact, max_prepared_xacts, xl_parameter_change::max_prepared_xacts, ControlFileData::max_prepared_xacts, max_wal_senders, xl_parameter_change::max_wal_senders, ControlFileData::max_wal_senders, max_worker_processes, xl_parameter_change::max_worker_processes, ControlFileData::max_worker_processes, MaxConnections, xl_parameter_change::MaxConnections, ControlFileData::MaxConnections, track_commit_timestamp, xl_parameter_change::track_commit_timestamp, ControlFileData::track_commit_timestamp, UpdateControlFile(), wal_level, xl_parameter_change::wal_level, ControlFileData::wal_level, wal_log_hints, xl_parameter_change::wal_log_hints, ControlFileData::wal_log_hints, XLOG_PARAMETER_CHANGE, XLogBeginInsert(), XLogFlush(), XLogInsert(), XLogIsNeeded, and XLogRegisterData().

Referenced by StartupXLOG().

◆ XLogRestorePoint()

XLogRecPtr XLogRestorePoint ( const char *  rpName)

Definition at line 8078 of file xlog.c.

8079{
8080 XLogRecPtr RecPtr;
8081 xl_restore_point xlrec;
8082
8083 xlrec.rp_time = GetCurrentTimestamp();
8084 strlcpy(xlrec.rp_name, rpName, MAXFNAMELEN);
8085
8087 XLogRegisterData((char *) &xlrec, sizeof(xl_restore_point));
8088
8089 RecPtr = XLogInsert(RM_XLOG_ID, XLOG_RESTORE_POINT);
8090
8091 ereport(LOG,
8092 (errmsg("restore point \"%s\" created at %X/%X",
8093 rpName, LSN_FORMAT_ARGS(RecPtr))));
8094
8095 return RecPtr;
8096}
char rp_name[MAXFNAMELEN]
TimestampTz rp_time

References ereport, errmsg(), GetCurrentTimestamp(), LOG, LSN_FORMAT_ARGS, MAXFNAMELEN, xl_restore_point::rp_name, xl_restore_point::rp_time, strlcpy(), XLOG_RESTORE_POINT, XLogBeginInsert(), XLogInsert(), and XLogRegisterData().

Referenced by pg_create_restore_point().

◆ XLogSetAsyncXactLSN()

void XLogSetAsyncXactLSN ( XLogRecPtr  asyncXactLSN)

Definition at line 2631 of file xlog.c.

2632{
2633 XLogRecPtr WriteRqstPtr = asyncXactLSN;
2634 bool sleeping;
2635 bool wakeup = false;
2636 XLogRecPtr prevAsyncXactLSN;
2637
2639 sleeping = XLogCtl->WalWriterSleeping;
2640 prevAsyncXactLSN = XLogCtl->asyncXactLSN;
2641 if (XLogCtl->asyncXactLSN < asyncXactLSN)
2642 XLogCtl->asyncXactLSN = asyncXactLSN;
2644
2645 /*
2646 * If somebody else already called this function with a more aggressive
2647 * LSN, they will have done what we needed (and perhaps more).
2648 */
2649 if (asyncXactLSN <= prevAsyncXactLSN)
2650 return;
2651
2652 /*
2653 * If the WALWriter is sleeping, kick it to make it come out of low-power
2654 * mode, so that this async commit will reach disk within the expected
2655 * amount of time. Otherwise, determine whether it has enough WAL
2656 * available to flush, the same way that XLogBackgroundFlush() does.
2657 */
2658 if (sleeping)
2659 wakeup = true;
2660 else
2661 {
2662 int flushblocks;
2663
2665
2666 flushblocks =
2667 WriteRqstPtr / XLOG_BLCKSZ - LogwrtResult.Flush / XLOG_BLCKSZ;
2668
2669 if (WalWriterFlushAfter == 0 || flushblocks >= WalWriterFlushAfter)
2670 wakeup = true;
2671 }
2672
2673 if (wakeup)
2674 {
2675 volatile PROC_HDR *procglobal = ProcGlobal;
2676 ProcNumber walwriterProc = procglobal->walwriterProc;
2677
2678 if (walwriterProc != INVALID_PROC_NUMBER)
2679 SetLatch(&GetPGProcByNumber(walwriterProc)->procLatch);
2680 }
2681}
void SetLatch(Latch *latch)
Definition: latch.c:632
#define GetPGProcByNumber(n)
Definition: proc.h:436
#define INVALID_PROC_NUMBER
Definition: procnumber.h:26
int ProcNumber
Definition: procnumber.h:24
PROC_HDR * ProcGlobal
Definition: proc.c:78
Definition: proc.h:382
ProcNumber walwriterProc
Definition: proc.h:420
static TimestampTz wakeup[NUM_WALRCV_WAKEUPS]
Definition: walreceiver.c:129

References XLogCtlData::asyncXactLSN, XLogwrtResult::Flush, GetPGProcByNumber, XLogCtlData::info_lck, INVALID_PROC_NUMBER, LogwrtResult, ProcGlobal, RefreshXLogWriteResult, SetLatch(), SpinLockAcquire, SpinLockRelease, wakeup, WalWriterFlushAfter, PROC_HDR::walwriterProc, XLogCtlData::WalWriterSleeping, and XLogCtl.

Referenced by AbortTransaction(), LogCurrentRunningXacts(), RecordTransactionAbort(), and RecordTransactionCommit().

◆ XLogSetReplicationSlotMinimumLSN()

void XLogSetReplicationSlotMinimumLSN ( XLogRecPtr  lsn)

◆ XLOGShmemInit()

void XLOGShmemInit ( void  )

Definition at line 4918 of file xlog.c.

4919{
4920 bool foundCFile,
4921 foundXLog;
4922 char *allocptr;
4923 int i;
4924 ControlFileData *localControlFile;
4925
4926#ifdef WAL_DEBUG
4927
4928 /*
4929 * Create a memory context for WAL debugging that's exempt from the normal
4930 * "no pallocs in critical section" rule. Yes, that can lead to a PANIC if
4931 * an allocation fails, but wal_debug is not for production use anyway.
4932 */
4933 if (walDebugCxt == NULL)
4934 {
4936 "WAL Debug",
4938 MemoryContextAllowInCriticalSection(walDebugCxt, true);
4939 }
4940#endif
4941
4942
4943 XLogCtl = (XLogCtlData *)
4944 ShmemInitStruct("XLOG Ctl", XLOGShmemSize(), &foundXLog);
4945
4946 localControlFile = ControlFile;
4948 ShmemInitStruct("Control File", sizeof(ControlFileData), &foundCFile);
4949
4950 if (foundCFile || foundXLog)
4951 {
4952 /* both should be present or neither */
4953 Assert(foundCFile && foundXLog);
4954
4955 /* Initialize local copy of WALInsertLocks */
4957
4958 if (localControlFile)
4959 pfree(localControlFile);
4960 return;
4961 }
4962 memset(XLogCtl, 0, sizeof(XLogCtlData));
4963
4964 /*
4965 * Already have read control file locally, unless in bootstrap mode. Move
4966 * contents into shared memory.
4967 */
4968 if (localControlFile)
4969 {
4970 memcpy(ControlFile, localControlFile, sizeof(ControlFileData));
4971 pfree(localControlFile);
4972 }
4973
4974 /*
4975 * Since XLogCtlData contains XLogRecPtr fields, its sizeof should be a
4976 * multiple of the alignment for same, so no extra alignment padding is
4977 * needed here.
4978 */
4979 allocptr = ((char *) XLogCtl) + sizeof(XLogCtlData);
4980 XLogCtl->xlblocks = (pg_atomic_uint64 *) allocptr;
4981 allocptr += sizeof(pg_atomic_uint64) * XLOGbuffers;
4982
4983 for (i = 0; i < XLOGbuffers; i++)
4984 {
4986 }
4987
4988 /* WAL insertion locks. Ensure they're aligned to the full padded size */
4989 allocptr += sizeof(WALInsertLockPadded) -
4990 ((uintptr_t) allocptr) % sizeof(WALInsertLockPadded);
4992 (WALInsertLockPadded *) allocptr;
4993 allocptr += sizeof(WALInsertLockPadded) * NUM_XLOGINSERT_LOCKS;
4994
4995 for (i = 0; i < NUM_XLOGINSERT_LOCKS; i++)
4996 {
5000 }
5001
5002 /*
5003 * Align the start of the page buffers to a full xlog block size boundary.
5004 * This simplifies some calculations in XLOG insertion. It is also
5005 * required for O_DIRECT.
5006 */
5007 allocptr = (char *) TYPEALIGN(XLOG_BLCKSZ, allocptr);
5008 XLogCtl->pages = allocptr;
5009 memset(XLogCtl->pages, 0, (Size) XLOG_BLCKSZ * XLOGbuffers);
5010
5011 /*
5012 * Do basic initialization of XLogCtl shared data. (StartupXLOG will fill
5013 * in additional info.)
5014 */
5018 XLogCtl->WalWriterSleeping = false;
5019
5026}
static void pg_atomic_init_u64(volatile pg_atomic_uint64 *ptr, uint64 val)
Definition: atomics.h:453
struct pg_atomic_uint64 pg_atomic_uint64
void LWLockInitialize(LWLock *lock, int tranche_id)
Definition: lwlock.c:707
@ LWTRANCHE_WAL_INSERT
Definition: lwlock.h:186
MemoryContext TopMemoryContext
Definition: mcxt.c:149
void MemoryContextAllowInCriticalSection(MemoryContext context, bool allow)
Definition: mcxt.c:694
#define AllocSetContextCreate
Definition: memutils.h:129
#define ALLOCSET_DEFAULT_SIZES
Definition: memutils.h:160
void * ShmemInitStruct(const char *name, Size size, bool *foundPtr)
Definition: shmem.c:382
#define SpinLockInit(lock)
Definition: spin.h:57
int XLogCacheBlck
Definition: xlog.c:494
WALInsertLockPadded * WALInsertLocks
Definition: xlog.c:444
slock_t insertpos_lck
Definition: xlog.c:398
union WALInsertLockPadded WALInsertLockPadded
Size XLOGShmemSize(void)
Definition: xlog.c:4868
struct XLogCtlData XLogCtlData

References ALLOCSET_DEFAULT_SIZES, AllocSetContextCreate, Assert, ControlFile, i, XLogCtlData::info_lck, XLogCtlData::Insert, XLogCtlInsert::insertpos_lck, XLogCtlData::InstallXLogFileSegmentActive, InvalidXLogRecPtr, WALInsertLockPadded::l, WALInsertLock::lastImportantAt, XLogCtlData::logFlushResult, XLogCtlData::logInsertResult, XLogCtlData::logWriteResult, LWLockInitialize(), LWTRANCHE_WAL_INSERT, MemoryContextAllowInCriticalSection(), NUM_XLOGINSERT_LOCKS, XLogCtlData::pages, pfree(), pg_atomic_init_u64(), RECOVERY_STATE_CRASH, XLogCtlData::SharedRecoveryState, ShmemInitStruct(), SpinLockInit, TopMemoryContext, TYPEALIGN, XLogCtlData::unloggedLSN, XLogCtlInsert::WALInsertLocks, WALInsertLocks, XLogCtlData::WalWriterSleeping, XLogCtlData::xlblocks, XLOGbuffers, XLogCtlData::XLogCacheBlck, XLogCtl, and XLOGShmemSize().

Referenced by CreateOrAttachShmemStructs().

◆ XLOGShmemSize()

Size XLOGShmemSize ( void  )

Definition at line 4868 of file xlog.c.

4869{
4870 Size size;
4871
4872 /*
4873 * If the value of wal_buffers is -1, use the preferred auto-tune value.
4874 * This isn't an amazingly clean place to do this, but we must wait till
4875 * NBuffers has received its final value, and must do it before using the
4876 * value of XLOGbuffers to do anything important.
4877 *
4878 * We prefer to report this value's source as PGC_S_DYNAMIC_DEFAULT.
4879 * However, if the DBA explicitly set wal_buffers = -1 in the config file,
4880 * then PGC_S_DYNAMIC_DEFAULT will fail to override that and we must force
4881 * the matter with PGC_S_OVERRIDE.
4882 */
4883 if (XLOGbuffers == -1)
4884 {
4885 char buf[32];
4886
4887 snprintf(buf, sizeof(buf), "%d", XLOGChooseNumBuffers());
4888 SetConfigOption("wal_buffers", buf, PGC_POSTMASTER,
4890 if (XLOGbuffers == -1) /* failed to apply it? */
4891 SetConfigOption("wal_buffers", buf, PGC_POSTMASTER,
4893 }
4894 Assert(XLOGbuffers > 0);
4895
4896 /* XLogCtl */
4897 size = sizeof(XLogCtlData);
4898
4899 /* WAL insertion locks, plus alignment */
4901 /* xlblocks array */
4903 /* extra alignment padding for XLOG I/O buffers */
4904 size = add_size(size, Max(XLOG_BLCKSZ, PG_IO_ALIGN_SIZE));
4905 /* and the buffers themselves */
4906 size = add_size(size, mul_size(XLOG_BLCKSZ, XLOGbuffers));
4907
4908 /*
4909 * Note: we don't count ControlFileData, it comes out of the "slop factor"
4910 * added by CreateSharedMemoryAndSemaphores. This lets us use this
4911 * routine again below to compute the actual allocation size.
4912 */
4913
4914 return size;
4915}
#define Max(x, y)
Definition: c.h:952
@ PGC_S_OVERRIDE
Definition: guc.h:119
@ PGC_POSTMASTER
Definition: guc.h:70
#define PG_IO_ALIGN_SIZE
Size add_size(Size s1, Size s2)
Definition: shmem.c:488
Size mul_size(Size s1, Size s2)
Definition: shmem.c:505

References add_size(), Assert, buf, Max, mul_size(), NUM_XLOGINSERT_LOCKS, PG_IO_ALIGN_SIZE, PGC_POSTMASTER, PGC_S_DYNAMIC_DEFAULT, PGC_S_OVERRIDE, SetConfigOption(), size, snprintf, XLOGbuffers, and XLOGChooseNumBuffers().

Referenced by CalculateShmemSize(), and XLOGShmemInit().

◆ XLogShutdownWalRcv()

void XLogShutdownWalRcv ( void  )

Definition at line 9473 of file xlog.c.

9474{
9476
9477 LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
9479 LWLockRelease(ControlFileLock);
9480}
void ShutdownWalRcv(void)

References XLogCtlData::InstallXLogFileSegmentActive, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), ShutdownWalRcv(), and XLogCtl.

Referenced by FinishWalRecovery(), and WaitForWALToBecomeAvailable().

◆ XLogWrite()

static void XLogWrite ( XLogwrtRqst  WriteRqst,
TimeLineID  tli,
bool  flexible 
)
static

Definition at line 2314 of file xlog.c.

2315{
2316 bool ispartialpage;
2317 bool last_iteration;
2318 bool finishing_seg;
2319 int curridx;
2320 int npages;
2321 int startidx;
2322 uint32 startoffset;
2323
2324 /* We should always be inside a critical section here */
2326
2327 /*
2328 * Update local LogwrtResult (caller probably did this already, but...)
2329 */
2331
2332 /*
2333 * Since successive pages in the xlog cache are consecutively allocated,
2334 * we can usually gather multiple pages together and issue just one
2335 * write() call. npages is the number of pages we have determined can be
2336 * written together; startidx is the cache block index of the first one,
2337 * and startoffset is the file offset at which it should go. The latter
2338 * two variables are only valid when npages > 0, but we must initialize
2339 * all of them to keep the compiler quiet.
2340 */
2341 npages = 0;
2342 startidx = 0;
2343 startoffset = 0;
2344
2345 /*
2346 * Within the loop, curridx is the cache block index of the page to
2347 * consider writing. Begin at the buffer containing the next unwritten
2348 * page, or last partially written page.
2349 */
2351
2352 while (LogwrtResult.Write < WriteRqst.Write)
2353 {
2354 /*
2355 * Make sure we're not ahead of the insert process. This could happen
2356 * if we're passed a bogus WriteRqst.Write that is past the end of the
2357 * last page that's been initialized by AdvanceXLInsertBuffer.
2358 */
2359 XLogRecPtr EndPtr = pg_atomic_read_u64(&XLogCtl->xlblocks[curridx]);
2360
2361 if (LogwrtResult.Write >= EndPtr)
2362 elog(PANIC, "xlog write request %X/%X is past end of log %X/%X",
2364 LSN_FORMAT_ARGS(EndPtr));
2365
2366 /* Advance LogwrtResult.Write to end of current buffer page */
2367 LogwrtResult.Write = EndPtr;
2368 ispartialpage = WriteRqst.Write < LogwrtResult.Write;
2369
2372 {
2373 /*
2374 * Switch to new logfile segment. We cannot have any pending
2375 * pages here (since we dump what we have at segment end).
2376 */
2377 Assert(npages == 0);
2378 if (openLogFile >= 0)
2379 XLogFileClose();
2382 openLogTLI = tli;
2383
2384 /* create/use new log file */
2387 }
2388
2389 /* Make sure we have the current logfile open */
2390 if (openLogFile < 0)
2391 {
2394 openLogTLI = tli;
2397 }
2398
2399 /* Add current page to the set of pending pages-to-dump */
2400 if (npages == 0)
2401 {
2402 /* first of group */
2403 startidx = curridx;
2404 startoffset = XLogSegmentOffset(LogwrtResult.Write - XLOG_BLCKSZ,
2406 }
2407 npages++;
2408
2409 /*
2410 * Dump the set if this will be the last loop iteration, or if we are
2411 * at the last page of the cache area (since the next page won't be
2412 * contiguous in memory), or if we are at the end of the logfile
2413 * segment.
2414 */
2415 last_iteration = WriteRqst.Write <= LogwrtResult.Write;
2416
2417 finishing_seg = !ispartialpage &&
2418 (startoffset + npages * XLOG_BLCKSZ) >= wal_segment_size;
2419
2420 if (last_iteration ||
2421 curridx == XLogCtl->XLogCacheBlck ||
2422 finishing_seg)
2423 {
2424 char *from;
2425 Size nbytes;
2426 Size nleft;
2427 ssize_t written;
2429
2430 /* OK to write the page(s) */
2431 from = XLogCtl->pages + startidx * (Size) XLOG_BLCKSZ;
2432 nbytes = npages * (Size) XLOG_BLCKSZ;
2433 nleft = nbytes;
2434 do
2435 {
2436 errno = 0;
2437
2438 /* Measure I/O timing to write WAL data */
2441 else
2443
2444 pgstat_report_wait_start(WAIT_EVENT_WAL_WRITE);
2445 written = pg_pwrite(openLogFile, from, nleft, startoffset);
2447
2448 /*
2449 * Increment the I/O timing and the number of times WAL data
2450 * were written out to disk.
2451 */
2453 {
2454 instr_time end;
2455
2458 }
2459
2461
2462 if (written <= 0)
2463 {
2464 char xlogfname[MAXFNAMELEN];
2465 int save_errno;
2466
2467 if (errno == EINTR)
2468 continue;
2469
2470 save_errno = errno;
2471 XLogFileName(xlogfname, tli, openLogSegNo,
2473 errno = save_errno;
2474 ereport(PANIC,
2476 errmsg("could not write to log file \"%s\" at offset %u, length %zu: %m",
2477 xlogfname, startoffset, nleft)));
2478 }
2479 nleft -= written;
2480 from += written;
2481 startoffset += written;
2482 } while (nleft > 0);
2483
2484 npages = 0;
2485
2486 /*
2487 * If we just wrote the whole last page of a logfile segment,
2488 * fsync the segment immediately. This avoids having to go back
2489 * and re-open prior segments when an fsync request comes along
2490 * later. Doing it here ensures that one and only one backend will
2491 * perform this fsync.
2492 *
2493 * This is also the right place to notify the Archiver that the
2494 * segment is ready to copy to archival storage, and to update the
2495 * timer for archive_timeout, and to signal for a checkpoint if
2496 * too many logfile segments have been used since the last
2497 * checkpoint.
2498 */
2499 if (finishing_seg)
2500 {
2502
2503 /* signal that we need to wakeup walsenders later */
2505
2506 LogwrtResult.Flush = LogwrtResult.Write; /* end of page */
2507
2508 if (XLogArchivingActive())
2510
2511 XLogCtl->lastSegSwitchTime = (pg_time_t) time(NULL);
2513
2514 /*
2515 * Request a checkpoint if we've consumed too much xlog since
2516 * the last one. For speed, we first check using the local
2517 * copy of RedoRecPtr, which might be out of date; if it looks
2518 * like a checkpoint is needed, forcibly update RedoRecPtr and
2519 * recheck.
2520 */
2522 {
2523 (void) GetRedoRecPtr();
2526 }
2527 }
2528 }
2529
2530 if (ispartialpage)
2531 {
2532 /* Only asked to write a partial page */
2533 LogwrtResult.Write = WriteRqst.Write;
2534 break;
2535 }
2536 curridx = NextBufIdx(curridx);
2537
2538 /* If flexible, break out of loop as soon as we wrote something */
2539 if (flexible && npages == 0)
2540 break;
2541 }
2542
2543 Assert(npages == 0);
2544
2545 /*
2546 * If asked to flush, do so
2547 */
2548 if (LogwrtResult.Flush < WriteRqst.Flush &&
2550 {
2551 /*
2552 * Could get here without iterating above loop, in which case we might
2553 * have no open file or the wrong one. However, we do not need to
2554 * fsync more than one file.
2555 */
2558 {
2559 if (openLogFile >= 0 &&
2562 XLogFileClose();
2563 if (openLogFile < 0)
2564 {
2567 openLogTLI = tli;
2570 }
2571
2573 }
2574
2575 /* signal that we need to wakeup walsenders later */
2577
2579 }
2580
2581 /*
2582 * Update shared-memory status
2583 *
2584 * We make sure that the shared 'request' values do not fall behind the
2585 * 'result' values. This is not absolutely essential, but it saves some
2586 * code in a couple of places.
2587 */
2594
2595 /*
2596 * We write Write first, bar, then Flush. When reading, the opposite must
2597 * be done (with a matching barrier in between), so that we always see a
2598 * Flush value that trails behind the Write value seen.
2599 */
2603
2604#ifdef USE_ASSERT_CHECKING
2605 {
2609
2615
2616 /* WAL written to disk is always ahead of WAL flushed */
2617 Assert(Write >= Flush);
2618
2619 /* WAL inserted to buffers is always ahead of WAL written */
2620 Assert(Insert >= Write);
2621 }
2622#endif
2623}
void ReserveExternalFD(void)
Definition: fd.c:1220
volatile uint32 CritSectionCount
Definition: globals.c:44
PgStat_Counter wal_write
Definition: pgstat.h:520
instr_time wal_write_time
Definition: pgstat.h:522
XLogRecPtr Flush
Definition: walreceiver.c:111
XLogRecPtr Write
Definition: walreceiver.c:110
#define WalSndWakeupRequest()
Definition: walsender.h:58
#define EINTR
Definition: win32_port.h:374
XLogRecPtr GetRedoRecPtr(void)
Definition: xlog.c:6437
int XLogFileOpen(XLogSegNo segno, TimeLineID tli)
Definition: xlog.c:3618
#define NextBufIdx(idx)
Definition: xlog.c:584
void issue_xlog_fsync(int fd, XLogSegNo segno, TimeLineID tli)
Definition: xlog.c:8683
bool XLogCheckpointNeeded(XLogSegNo new_segno)
Definition: xlog.c:2290
void XLogArchiveNotifySeg(XLogSegNo segno, TimeLineID tli)
Definition: xlogarchive.c:492

References Assert, CHECKPOINT_CAUSE_XLOG, CritSectionCount, EINTR, elog, ereport, errcode_for_file_access(), errmsg(), XLogwrtRqst::Flush, XLogwrtResult::Flush, Flush, GetRedoRecPtr(), XLogCtlData::info_lck, Insert(), INSTR_TIME_ACCUM_DIFF, INSTR_TIME_SET_CURRENT, INSTR_TIME_SET_ZERO, issue_xlog_fsync(), IsUnderPostmaster, XLogCtlData::lastSegSwitchLSN, XLogCtlData::lastSegSwitchTime, XLogCtlData::logFlushResult, XLogCtlData::logInsertResult, XLogCtlData::logWriteResult, LogwrtResult, XLogCtlData::LogwrtRqst, LSN_FORMAT_ARGS, MAXFNAMELEN, NextBufIdx, openLogFile, openLogSegNo, openLogTLI, XLogCtlData::pages, PANIC, PendingWalStats, pg_atomic_read_u64(), pg_atomic_write_u64(), pg_pwrite, pg_read_barrier, pg_write_barrier, pgstat_report_wait_end(), pgstat_report_wait_start(), RefreshXLogWriteResult, RequestCheckpoint(), ReserveExternalFD(), SpinLockAcquire, SpinLockRelease, start, track_wal_io_timing, wal_segment_size, wal_sync_method, WAL_SYNC_METHOD_OPEN, WAL_SYNC_METHOD_OPEN_DSYNC, PgStat_PendingWalStats::wal_write, PgStat_PendingWalStats::wal_write_time, WalSndWakeupRequest, XLogwrtRqst::Write, XLogwrtResult::Write, Write, XLogCtlData::xlblocks, XLByteInPrevSeg, XLByteToPrevSeg, XLogArchiveNotifySeg(), XLogArchivingActive, XLogCtlData::XLogCacheBlck, XLogCheckpointNeeded(), XLogCtl, XLogFileClose(), XLogFileInit(), XLogFileName(), XLogFileOpen(), XLogRecPtrToBufIdx, and XLogSegmentOffset.

Referenced by AdvanceXLInsertBuffer(), XLogBackgroundFlush(), and XLogFlush().

Variable Documentation

◆ archive_mode_options

const struct config_enum_entry archive_mode_options[]
Initial value:
= {
{"always", ARCHIVE_MODE_ALWAYS, false},
{"on", ARCHIVE_MODE_ON, false},
{"off", ARCHIVE_MODE_OFF, false},
{"true", ARCHIVE_MODE_ON, true},
{"false", ARCHIVE_MODE_OFF, true},
{"yes", ARCHIVE_MODE_ON, true},
{"no", ARCHIVE_MODE_OFF, true},
{"1", ARCHIVE_MODE_ON, true},
{"0", ARCHIVE_MODE_OFF, true},
{NULL, 0, false}
}
@ ARCHIVE_MODE_ALWAYS
Definition: xlog.h:67
@ ARCHIVE_MODE_OFF
Definition: xlog.h:65
@ ARCHIVE_MODE_ON
Definition: xlog.h:66

Definition at line 191 of file xlog.c.

◆ check_wal_consistency_checking_deferred

bool check_wal_consistency_checking_deferred = false
static

Definition at line 166 of file xlog.c.

Referenced by check_wal_consistency_checking(), and InitializeWalConsistencyChecking().

◆ CheckPointDistanceEstimate

double CheckPointDistanceEstimate = 0
static

Definition at line 159 of file xlog.c.

Referenced by LogCheckpointEnd(), UpdateCheckPointDistanceEstimate(), and XLOGfileslop().

◆ CheckPointSegments

int CheckPointSegments

◆ CheckpointStats

◆ CommitDelay

int CommitDelay = 0

Definition at line 132 of file xlog.c.

Referenced by XLogFlush().

◆ CommitSiblings

int CommitSiblings = 5

Definition at line 133 of file xlog.c.

Referenced by XLogFlush().

◆ ControlFile

◆ doPageWrites

bool doPageWrites
static

◆ EnableHotStandby

◆ fullPageWrites

bool fullPageWrites = true

Definition at line 122 of file xlog.c.

Referenced by BootStrapXLOG(), and UpdateFullPageWrites().

◆ holdingAllLocks

bool holdingAllLocks = false
static

◆ lastFullPageWrites

bool lastFullPageWrites
static

Definition at line 217 of file xlog.c.

Referenced by StartupXLOG(), and xlog_redo().

◆ LocalMinRecoveryPoint

XLogRecPtr LocalMinRecoveryPoint
static

◆ LocalMinRecoveryPointTLI

TimeLineID LocalMinRecoveryPointTLI
static

◆ LocalRecoveryInProgress

bool LocalRecoveryInProgress = true
static

Definition at line 224 of file xlog.c.

Referenced by RecoveryInProgress().

◆ LocalXLogInsertAllowed

int LocalXLogInsertAllowed = -1
static

Definition at line 236 of file xlog.c.

Referenced by CreateCheckPoint(), LocalSetXLogInsertAllowed(), and XLogInsertAllowed().

◆ log_checkpoints

bool log_checkpoints = true

◆ LogwrtResult

◆ max_slot_wal_keep_size_mb

int max_slot_wal_keep_size_mb = -1

Definition at line 135 of file xlog.c.

Referenced by KeepLogSeg(), and pg_get_replication_slots().

◆ max_wal_size_mb

int max_wal_size_mb = 1024

◆ min_wal_size_mb

int min_wal_size_mb = 80

Definition at line 115 of file xlog.c.

Referenced by ReadControlFile(), and XLOGfileslop().

◆ MyLockNo

int MyLockNo = 0
static

◆ openLogFile

int openLogFile = -1
static

◆ openLogSegNo

XLogSegNo openLogSegNo = 0
static

Definition at line 636 of file xlog.c.

Referenced by assign_wal_sync_method(), XLogBackgroundFlush(), XLogFileClose(), and XLogWrite().

◆ openLogTLI

TimeLineID openLogTLI = 0
static

Definition at line 637 of file xlog.c.

Referenced by assign_wal_sync_method(), BootStrapXLOG(), XLogFileClose(), and XLogWrite().

◆ PrevCheckPointDistance

double PrevCheckPointDistance = 0
static

Definition at line 160 of file xlog.c.

Referenced by LogCheckpointEnd(), and UpdateCheckPointDistanceEstimate().

◆ ProcLastRecPtr

◆ RedoRecPtr

◆ sessionBackupState

SessionBackupState sessionBackupState = SESSION_BACKUP_NONE
static

◆ track_wal_io_timing

bool track_wal_io_timing = false

Definition at line 137 of file xlog.c.

Referenced by issue_xlog_fsync(), and XLogWrite().

◆ updateMinRecoveryPoint

bool updateMinRecoveryPoint = true
static

Definition at line 648 of file xlog.c.

Referenced by SwitchIntoArchiveRecovery(), UpdateMinRecoveryPoint(), and XLogNeedsFlush().

◆ UsableBytesInSegment

int UsableBytesInSegment
static

◆ wal_compression

int wal_compression = WAL_COMPRESSION_NONE

Definition at line 124 of file xlog.c.

Referenced by XLogCompressBackupBlock(), and XLogRecordAssemble().

◆ wal_consistency_checking

bool* wal_consistency_checking = NULL

Definition at line 126 of file xlog.c.

Referenced by assign_wal_consistency_checking(), and XLogRecordAssemble().

◆ wal_consistency_checking_string

char* wal_consistency_checking_string = NULL

Definition at line 125 of file xlog.c.

Referenced by InitializeWalConsistencyChecking().

◆ wal_decode_buffer_size

int wal_decode_buffer_size = 512 * 1024

Definition at line 136 of file xlog.c.

Referenced by InitWalRecovery().

◆ wal_init_zero

bool wal_init_zero = true

Definition at line 127 of file xlog.c.

Referenced by XLogFileInitInternal().

◆ wal_keep_size_mb

int wal_keep_size_mb = 0

Definition at line 116 of file xlog.c.

Referenced by KeepLogSeg(), and pg_get_replication_slots().

◆ wal_level

◆ wal_log_hints

bool wal_log_hints = false

Definition at line 123 of file xlog.c.

Referenced by InitControlFile(), and XLogReportParameters().

◆ wal_recycle

bool wal_recycle = true

Definition at line 128 of file xlog.c.

Referenced by RemoveXlogFile().

◆ wal_retrieve_retry_interval

int wal_retrieve_retry_interval = 5000

◆ wal_segment_size

int wal_segment_size = DEFAULT_XLOG_SEG_SIZE

Definition at line 143 of file xlog.c.

Referenced by AdvanceXLInsertBuffer(), assign_wal_sync_method(), BootStrapXLOG(), build_backup_content(), CalculateCheckpointSegments(), CheckArchiveTimeout(), CheckXLogRemoved(), CleanupAfterArchiveRecovery(), copy_replication_slot(), CopyXLogRecordToWAL(), CreateCheckPoint(), CreateOverwriteContrecordRecord(), CreateRestartPoint(), do_pg_backup_stop(), ExecuteRecoveryCommand(), FinishWalRecovery(), GetOldestUnsummarizedLSN(), GetWALAvailability(), GetXLogBuffer(), InitWalRecovery(), InitXLogReaderState(), InstallXLogFileSegment(), InvalidateObsoleteReplicationSlots(), IsCheckpointOnSchedule(), issue_xlog_fsync(), KeepLogSeg(), MaybeRemoveOldWalSummaries(), perform_base_backup(), pg_control_checkpoint(), pg_get_replication_slots(), pg_split_walfile_name(), pg_walfile_name(), pg_walfile_name_offset(), PreallocXlogFiles(), ReadControlFile(), ReadRecord(), RemoveNonParentXlogFiles(), RemoveOldXlogFiles(), ReorderBufferRestoreChanges(), ReorderBufferRestoreCleanup(), ReorderBufferSerializedPath(), ReorderBufferSerializeTXN(), ReplicationSlotReserveWal(), RequestXLogStreaming(), reserve_wal_for_local_slot(), ReserveXLogSwitch(), RestoreArchivedFile(), StartReplication(), StartupDecodingContext(), SummarizeWAL(), UpdateLastRemovedPtr(), WALReadRaiseError(), WalReceiverMain(), WalSndSegmentOpen(), WriteControlFile(), XLogArchiveNotifySeg(), XLogBackgroundFlush(), XLogBytePosToEndRecPtr(), XLogBytePosToRecPtr(), XLogCheckpointNeeded(), XLOGChooseNumBuffers(), XLogFileClose(), XLogFileCopy(), XLogFileInitInternal(), XLogFileOpen(), XLogFileRead(), XLogFileReadAnyTLI(), XLOGfileslop(), XLogGetOldestSegno(), XLogInitNewTimeline(), XLogInsertRecord(), XLogPageRead(), XLogReaderAllocate(), XlogReadTwoPhaseData(), XLogRecPtrToBytePos(), XLogWalRcvClose(), XLogWalRcvWrite(), and XLogWrite().

◆ wal_sync_method

◆ wal_sync_method_options

const struct config_enum_entry wal_sync_method_options[]
Initial value:
= {
{"fsync", WAL_SYNC_METHOD_FSYNC, false},
{"fdatasync", WAL_SYNC_METHOD_FDATASYNC, false},
{NULL, 0, false}
}

Definition at line 171 of file xlog.c.

◆ WALInsertLocks

◆ XactLastCommitEnd

◆ XactLastRecEnd

◆ XLogArchiveCommand

char* XLogArchiveCommand = NULL

◆ XLogArchiveMode

◆ XLogArchiveTimeout

int XLogArchiveTimeout = 0

Definition at line 118 of file xlog.c.

Referenced by CheckArchiveTimeout(), and CheckpointerMain().

◆ XLOGbuffers

int XLOGbuffers = -1

Definition at line 117 of file xlog.c.

Referenced by check_wal_buffers(), XLOGShmemInit(), and XLOGShmemSize().

◆ XLogCtl