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dbcommands_xlog.h File Reference
#include "access/xlogreader.h"
#include "lib/stringinfo.h"
Include dependency graph for dbcommands_xlog.h:
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Data Structures

struct  xl_dbase_create_file_copy_rec
 
struct  xl_dbase_create_wal_log_rec
 
struct  xl_dbase_drop_rec
 

Macros

#define XLOG_DBASE_CREATE_FILE_COPY   0x00
 
#define XLOG_DBASE_CREATE_WAL_LOG   0x10
 
#define XLOG_DBASE_DROP   0x20
 
#define MinSizeOfDbaseDropRec   offsetof(xl_dbase_drop_rec, tablespace_ids)
 

Typedefs

typedef struct xl_dbase_create_file_copy_rec xl_dbase_create_file_copy_rec
 
typedef struct xl_dbase_create_wal_log_rec xl_dbase_create_wal_log_rec
 
typedef struct xl_dbase_drop_rec xl_dbase_drop_rec
 

Functions

void dbase_redo (XLogReaderState *rptr)
 
void dbase_desc (StringInfo buf, XLogReaderState *rptr)
 
const char * dbase_identify (uint8 info)
 

Macro Definition Documentation

◆ MinSizeOfDbaseDropRec

#define MinSizeOfDbaseDropRec   offsetof(xl_dbase_drop_rec, tablespace_ids)

Definition at line 54 of file dbcommands_xlog.h.

◆ XLOG_DBASE_CREATE_FILE_COPY

#define XLOG_DBASE_CREATE_FILE_COPY   0x00

Definition at line 21 of file dbcommands_xlog.h.

◆ XLOG_DBASE_CREATE_WAL_LOG

#define XLOG_DBASE_CREATE_WAL_LOG   0x10

Definition at line 22 of file dbcommands_xlog.h.

◆ XLOG_DBASE_DROP

#define XLOG_DBASE_DROP   0x20

Definition at line 23 of file dbcommands_xlog.h.

Typedef Documentation

◆ xl_dbase_create_file_copy_rec

◆ xl_dbase_create_wal_log_rec

◆ xl_dbase_drop_rec

Function Documentation

◆ dbase_desc()

void dbase_desc ( StringInfo  buf,
XLogReaderState rptr 
)

Definition at line 22 of file dbasedesc.c.

23 {
24  char *rec = XLogRecGetData(record);
25  uint8 info = XLogRecGetInfo(record) & ~XLR_INFO_MASK;
26 
27  if (info == XLOG_DBASE_CREATE_FILE_COPY)
28  {
31 
32  appendStringInfo(buf, "copy dir %u/%u to %u/%u",
33  xlrec->src_tablespace_id, xlrec->src_db_id,
34  xlrec->tablespace_id, xlrec->db_id);
35  }
36  else if (info == XLOG_DBASE_CREATE_WAL_LOG)
37  {
40 
41  appendStringInfo(buf, "create dir %u/%u",
42  xlrec->tablespace_id, xlrec->db_id);
43  }
44  else if (info == XLOG_DBASE_DROP)
45  {
46  xl_dbase_drop_rec *xlrec = (xl_dbase_drop_rec *) rec;
47  int i;
48 
50  for (i = 0; i < xlrec->ntablespaces; i++)
51  appendStringInfo(buf, " %u/%u",
52  xlrec->tablespace_ids[i], xlrec->db_id);
53  }
54 }
unsigned char uint8
Definition: c.h:439
#define XLOG_DBASE_CREATE_WAL_LOG
#define XLOG_DBASE_DROP
#define XLOG_DBASE_CREATE_FILE_COPY
int i
Definition: isn.c:73
static char * buf
Definition: pg_test_fsync.c:67
void appendStringInfo(StringInfo str, const char *fmt,...)
Definition: stringinfo.c:91
void appendStringInfoString(StringInfo str, const char *s)
Definition: stringinfo.c:176
Oid tablespace_ids[FLEXIBLE_ARRAY_MEMBER]
#define XLogRecGetInfo(decoder)
Definition: xlogreader.h:408
#define XLogRecGetData(decoder)
Definition: xlogreader.h:413
#define XLR_INFO_MASK
Definition: xlogrecord.h:62

References appendStringInfo(), appendStringInfoString(), buf, xl_dbase_create_file_copy_rec::db_id, xl_dbase_create_wal_log_rec::db_id, xl_dbase_drop_rec::db_id, i, xl_dbase_drop_rec::ntablespaces, xl_dbase_create_file_copy_rec::src_db_id, xl_dbase_create_file_copy_rec::src_tablespace_id, xl_dbase_create_file_copy_rec::tablespace_id, xl_dbase_create_wal_log_rec::tablespace_id, xl_dbase_drop_rec::tablespace_ids, XLOG_DBASE_CREATE_FILE_COPY, XLOG_DBASE_CREATE_WAL_LOG, XLOG_DBASE_DROP, XLogRecGetData, XLogRecGetInfo, and XLR_INFO_MASK.

◆ dbase_identify()

const char* dbase_identify ( uint8  info)

Definition at line 57 of file dbasedesc.c.

58 {
59  const char *id = NULL;
60 
61  switch (info & ~XLR_INFO_MASK)
62  {
64  id = "CREATE_FILE_COPY";
65  break;
67  id = "CREATE_WAL_LOG";
68  break;
69  case XLOG_DBASE_DROP:
70  id = "DROP";
71  break;
72  }
73 
74  return id;
75 }

References XLOG_DBASE_CREATE_FILE_COPY, XLOG_DBASE_CREATE_WAL_LOG, XLOG_DBASE_DROP, and XLR_INFO_MASK.

◆ dbase_redo()

void dbase_redo ( XLogReaderState rptr)

Definition at line 3015 of file dbcommands.c.

3016 {
3017  uint8 info = XLogRecGetInfo(record) & ~XLR_INFO_MASK;
3018 
3019  /* Backup blocks are not used in dbase records */
3020  Assert(!XLogRecHasAnyBlockRefs(record));
3021 
3022  if (info == XLOG_DBASE_CREATE_FILE_COPY)
3023  {
3026  char *src_path;
3027  char *dst_path;
3028  struct stat st;
3029 
3030  src_path = GetDatabasePath(xlrec->src_db_id, xlrec->src_tablespace_id);
3031  dst_path = GetDatabasePath(xlrec->db_id, xlrec->tablespace_id);
3032 
3033  /*
3034  * Our theory for replaying a CREATE is to forcibly drop the target
3035  * subdirectory if present, then re-copy the source data. This may be
3036  * more work than needed, but it is simple to implement.
3037  */
3038  if (stat(dst_path, &st) == 0 && S_ISDIR(st.st_mode))
3039  {
3040  if (!rmtree(dst_path, true))
3041  /* If this failed, copydir() below is going to error. */
3042  ereport(WARNING,
3043  (errmsg("some useless files may be left behind in old database directory \"%s\"",
3044  dst_path)));
3045  }
3046 
3047  /*
3048  * Force dirty buffers out to disk, to ensure source database is
3049  * up-to-date for the copy.
3050  */
3052 
3053  /* Close all sgmr fds in all backends. */
3055 
3056  /*
3057  * Copy this subdirectory to the new location
3058  *
3059  * We don't need to copy subdirectories
3060  */
3061  copydir(src_path, dst_path, false);
3062 
3063  pfree(src_path);
3064  pfree(dst_path);
3065  }
3066  else if (info == XLOG_DBASE_CREATE_WAL_LOG)
3067  {
3070  char *dbpath;
3071 
3072  dbpath = GetDatabasePath(xlrec->db_id, xlrec->tablespace_id);
3073 
3074  /* Create the database directory with the version file. */
3075  CreateDirAndVersionFile(dbpath, xlrec->db_id, xlrec->tablespace_id,
3076  true);
3077  pfree(dbpath);
3078  }
3079  else if (info == XLOG_DBASE_DROP)
3080  {
3081  xl_dbase_drop_rec *xlrec = (xl_dbase_drop_rec *) XLogRecGetData(record);
3082  char *dst_path;
3083  int i;
3084 
3085  if (InHotStandby)
3086  {
3087  /*
3088  * Lock database while we resolve conflicts to ensure that
3089  * InitPostgres() cannot fully re-execute concurrently. This
3090  * avoids backends re-connecting automatically to same database,
3091  * which can happen in some cases.
3092  *
3093  * This will lock out walsenders trying to connect to db-specific
3094  * slots for logical decoding too, so it's safe for us to drop
3095  * slots.
3096  */
3097  LockSharedObjectForSession(DatabaseRelationId, xlrec->db_id, 0, AccessExclusiveLock);
3099  }
3100 
3101  /* Drop any database-specific replication slots */
3103 
3104  /* Drop pages for this database that are in the shared buffer cache */
3105  DropDatabaseBuffers(xlrec->db_id);
3106 
3107  /* Also, clean out any fsync requests that might be pending in md.c */
3109 
3110  /* Clean out the xlog relcache too */
3111  XLogDropDatabase(xlrec->db_id);
3112 
3113  /* Close all sgmr fds in all backends. */
3115 
3116  for (i = 0; i < xlrec->ntablespaces; i++)
3117  {
3118  dst_path = GetDatabasePath(xlrec->db_id, xlrec->tablespace_ids[i]);
3119 
3120  /* And remove the physical files */
3121  if (!rmtree(dst_path, true))
3122  ereport(WARNING,
3123  (errmsg("some useless files may be left behind in old database directory \"%s\"",
3124  dst_path)));
3125  pfree(dst_path);
3126  }
3127 
3128  if (InHotStandby)
3129  {
3130  /*
3131  * Release locks prior to commit. XXX There is a race condition
3132  * here that may allow backends to reconnect, but the window for
3133  * this is small because the gap between here and commit is mostly
3134  * fairly small and it is unlikely that people will be dropping
3135  * databases that we are trying to connect to anyway.
3136  */
3137  UnlockSharedObjectForSession(DatabaseRelationId, xlrec->db_id, 0, AccessExclusiveLock);
3138  }
3139  }
3140  else
3141  elog(PANIC, "dbase_redo: unknown op code %u", info);
3142 }
void DropDatabaseBuffers(Oid dbid)
Definition: bufmgr.c:3404
void FlushDatabaseBuffers(Oid dbid)
Definition: bufmgr.c:3852
void copydir(char *fromdir, char *todir, bool recurse)
Definition: copydir.c:37
static void CreateDirAndVersionFile(char *dbpath, Oid dbid, Oid tsid, bool isRedo)
Definition: dbcommands.c:460
int errmsg(const char *fmt,...)
Definition: elog.c:904
#define WARNING
Definition: elog.h:30
#define PANIC
Definition: elog.h:36
#define elog(elevel,...)
Definition: elog.h:218
#define ereport(elevel,...)
Definition: elog.h:143
Assert(fmt[strlen(fmt) - 1] !='\n')
void UnlockSharedObjectForSession(Oid classid, Oid objid, uint16 objsubid, LOCKMODE lockmode)
Definition: lmgr.c:1106
void LockSharedObjectForSession(Oid classid, Oid objid, uint16 objsubid, LOCKMODE lockmode)
Definition: lmgr.c:1088
#define AccessExclusiveLock
Definition: lockdefs.h:43
void pfree(void *pointer)
Definition: mcxt.c:1175
void ForgetDatabaseSyncRequests(Oid dbid)
Definition: md.c:1039
void WaitForProcSignalBarrier(uint64 generation)
Definition: procsignal.c:392
uint64 EmitProcSignalBarrier(ProcSignalBarrierType type)
Definition: procsignal.c:332
@ PROCSIGNAL_BARRIER_SMGRRELEASE
Definition: procsignal.h:52
char * GetDatabasePath(Oid dbNode, Oid spcNode)
Definition: relpath.c:110
bool rmtree(const char *path, bool rmtopdir)
Definition: rmtree.c:42
void ReplicationSlotsDropDBSlots(Oid dboid)
Definition: slot.c:1038
void ResolveRecoveryConflictWithDatabase(Oid dbid)
Definition: standby.c:531
#define stat
Definition: win32_port.h:283
#define S_ISDIR(m)
Definition: win32_port.h:324
#define XLogRecHasAnyBlockRefs(decoder)
Definition: xlogreader.h:415
void XLogDropDatabase(Oid dbid)
Definition: xlogutils.c:666
#define InHotStandby
Definition: xlogutils.h:57

References AccessExclusiveLock, Assert(), copydir(), CreateDirAndVersionFile(), xl_dbase_create_file_copy_rec::db_id, xl_dbase_create_wal_log_rec::db_id, xl_dbase_drop_rec::db_id, DropDatabaseBuffers(), elog, EmitProcSignalBarrier(), ereport, errmsg(), FlushDatabaseBuffers(), ForgetDatabaseSyncRequests(), GetDatabasePath(), i, InHotStandby, LockSharedObjectForSession(), xl_dbase_drop_rec::ntablespaces, PANIC, pfree(), PROCSIGNAL_BARRIER_SMGRRELEASE, ReplicationSlotsDropDBSlots(), ResolveRecoveryConflictWithDatabase(), rmtree(), S_ISDIR, xl_dbase_create_file_copy_rec::src_db_id, xl_dbase_create_file_copy_rec::src_tablespace_id, stat::st_mode, stat, xl_dbase_create_file_copy_rec::tablespace_id, xl_dbase_create_wal_log_rec::tablespace_id, xl_dbase_drop_rec::tablespace_ids, UnlockSharedObjectForSession(), WaitForProcSignalBarrier(), WARNING, XLOG_DBASE_CREATE_FILE_COPY, XLOG_DBASE_CREATE_WAL_LOG, XLOG_DBASE_DROP, XLogDropDatabase(), XLogRecGetData, XLogRecGetInfo, XLogRecHasAnyBlockRefs, and XLR_INFO_MASK.