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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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Go to the source code of this file.

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 *record)
 
void dbase_desc (StringInfo buf, XLogReaderState *record)
 
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 record 
)

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:490
#define XLOG_DBASE_CREATE_WAL_LOG
#define XLOG_DBASE_DROP
#define XLOG_DBASE_CREATE_FILE_COPY
int i
Definition: isn.c:72
static char * buf
Definition: pg_test_fsync.c:72
void appendStringInfo(StringInfo str, const char *fmt,...)
Definition: stringinfo.c:94
void appendStringInfoString(StringInfo str, const char *s)
Definition: stringinfo.c:179
Oid tablespace_ids[FLEXIBLE_ARRAY_MEMBER]
#define XLogRecGetInfo(decoder)
Definition: xlogreader.h:410
#define XLogRecGetData(decoder)
Definition: xlogreader.h:415
#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 record)

Definition at line 3283 of file dbcommands.c.

3284 {
3285  uint8 info = XLogRecGetInfo(record) & ~XLR_INFO_MASK;
3286 
3287  /* Backup blocks are not used in dbase records */
3288  Assert(!XLogRecHasAnyBlockRefs(record));
3289 
3290  if (info == XLOG_DBASE_CREATE_FILE_COPY)
3291  {
3294  char *src_path;
3295  char *dst_path;
3296  char *parent_path;
3297  struct stat st;
3298 
3299  src_path = GetDatabasePath(xlrec->src_db_id, xlrec->src_tablespace_id);
3300  dst_path = GetDatabasePath(xlrec->db_id, xlrec->tablespace_id);
3301 
3302  /*
3303  * Our theory for replaying a CREATE is to forcibly drop the target
3304  * subdirectory if present, then re-copy the source data. This may be
3305  * more work than needed, but it is simple to implement.
3306  */
3307  if (stat(dst_path, &st) == 0 && S_ISDIR(st.st_mode))
3308  {
3309  if (!rmtree(dst_path, true))
3310  /* If this failed, copydir() below is going to error. */
3311  ereport(WARNING,
3312  (errmsg("some useless files may be left behind in old database directory \"%s\"",
3313  dst_path)));
3314  }
3315 
3316  /*
3317  * If the parent of the target path doesn't exist, create it now. This
3318  * enables us to create the target underneath later.
3319  */
3320  parent_path = pstrdup(dst_path);
3321  get_parent_directory(parent_path);
3322  if (stat(parent_path, &st) < 0)
3323  {
3324  if (errno != ENOENT)
3325  ereport(FATAL,
3326  errmsg("could not stat directory \"%s\": %m",
3327  dst_path));
3328 
3329  /* create the parent directory if needed and valid */
3330  recovery_create_dbdir(parent_path, true);
3331  }
3332  pfree(parent_path);
3333 
3334  /*
3335  * There's a case where the copy source directory is missing for the
3336  * same reason above. Create the empty source directory so that
3337  * copydir below doesn't fail. The directory will be dropped soon by
3338  * recovery.
3339  */
3340  if (stat(src_path, &st) < 0 && errno == ENOENT)
3341  recovery_create_dbdir(src_path, false);
3342 
3343  /*
3344  * Force dirty buffers out to disk, to ensure source database is
3345  * up-to-date for the copy.
3346  */
3348 
3349  /* Close all smgr fds in all backends. */
3351 
3352  /*
3353  * Copy this subdirectory to the new location
3354  *
3355  * We don't need to copy subdirectories
3356  */
3357  copydir(src_path, dst_path, false);
3358 
3359  pfree(src_path);
3360  pfree(dst_path);
3361  }
3362  else if (info == XLOG_DBASE_CREATE_WAL_LOG)
3363  {
3366  char *dbpath;
3367  char *parent_path;
3368 
3369  dbpath = GetDatabasePath(xlrec->db_id, xlrec->tablespace_id);
3370 
3371  /* create the parent directory if needed and valid */
3372  parent_path = pstrdup(dbpath);
3373  get_parent_directory(parent_path);
3374  recovery_create_dbdir(parent_path, true);
3375 
3376  /* Create the database directory with the version file. */
3377  CreateDirAndVersionFile(dbpath, xlrec->db_id, xlrec->tablespace_id,
3378  true);
3379  pfree(dbpath);
3380  }
3381  else if (info == XLOG_DBASE_DROP)
3382  {
3383  xl_dbase_drop_rec *xlrec = (xl_dbase_drop_rec *) XLogRecGetData(record);
3384  char *dst_path;
3385  int i;
3386 
3387  if (InHotStandby)
3388  {
3389  /*
3390  * Lock database while we resolve conflicts to ensure that
3391  * InitPostgres() cannot fully re-execute concurrently. This
3392  * avoids backends re-connecting automatically to same database,
3393  * which can happen in some cases.
3394  *
3395  * This will lock out walsenders trying to connect to db-specific
3396  * slots for logical decoding too, so it's safe for us to drop
3397  * slots.
3398  */
3399  LockSharedObjectForSession(DatabaseRelationId, xlrec->db_id, 0, AccessExclusiveLock);
3401  }
3402 
3403  /* Drop any database-specific replication slots */
3405 
3406  /* Drop pages for this database that are in the shared buffer cache */
3407  DropDatabaseBuffers(xlrec->db_id);
3408 
3409  /* Also, clean out any fsync requests that might be pending in md.c */
3411 
3412  /* Clean out the xlog relcache too */
3413  XLogDropDatabase(xlrec->db_id);
3414 
3415  /* Close all smgr fds in all backends. */
3417 
3418  for (i = 0; i < xlrec->ntablespaces; i++)
3419  {
3420  dst_path = GetDatabasePath(xlrec->db_id, xlrec->tablespace_ids[i]);
3421 
3422  /* And remove the physical files */
3423  if (!rmtree(dst_path, true))
3424  ereport(WARNING,
3425  (errmsg("some useless files may be left behind in old database directory \"%s\"",
3426  dst_path)));
3427  pfree(dst_path);
3428  }
3429 
3430  if (InHotStandby)
3431  {
3432  /*
3433  * Release locks prior to commit. XXX There is a race condition
3434  * here that may allow backends to reconnect, but the window for
3435  * this is small because the gap between here and commit is mostly
3436  * fairly small and it is unlikely that people will be dropping
3437  * databases that we are trying to connect to anyway.
3438  */
3439  UnlockSharedObjectForSession(DatabaseRelationId, xlrec->db_id, 0, AccessExclusiveLock);
3440  }
3441  }
3442  else
3443  elog(PANIC, "dbase_redo: unknown op code %u", info);
3444 }
void DropDatabaseBuffers(Oid dbid)
Definition: bufmgr.c:4386
void FlushDatabaseBuffers(Oid dbid)
Definition: bufmgr.c:4862
#define Assert(condition)
Definition: c.h:837
void copydir(const char *fromdir, const char *todir, bool recurse)
Definition: copydir.c:37
static void CreateDirAndVersionFile(char *dbpath, Oid dbid, Oid tsid, bool isRedo)
Definition: dbcommands.c:456
static void recovery_create_dbdir(char *path, bool only_tblspc)
Definition: dbcommands.c:3254
int errmsg(const char *fmt,...)
Definition: elog.c:1070
#define FATAL
Definition: elog.h:41
#define WARNING
Definition: elog.h:36
#define PANIC
Definition: elog.h:42
#define elog(elevel,...)
Definition: elog.h:225
#define ereport(elevel,...)
Definition: elog.h:149
void UnlockSharedObjectForSession(Oid classid, Oid objid, uint16 objsubid, LOCKMODE lockmode)
Definition: lmgr.c:1170
void LockSharedObjectForSession(Oid classid, Oid objid, uint16 objsubid, LOCKMODE lockmode)
Definition: lmgr.c:1152
#define AccessExclusiveLock
Definition: lockdefs.h:43
char * pstrdup(const char *in)
Definition: mcxt.c:1696
void pfree(void *pointer)
Definition: mcxt.c:1521
void ForgetDatabaseSyncRequests(Oid dbid)
Definition: md.c:1449
void get_parent_directory(char *path)
Definition: path.c:991
void WaitForProcSignalBarrier(uint64 generation)
Definition: procsignal.c:421
uint64 EmitProcSignalBarrier(ProcSignalBarrierType type)
Definition: procsignal.c:353
@ PROCSIGNAL_BARRIER_SMGRRELEASE
Definition: procsignal.h:56
char * GetDatabasePath(Oid dbOid, Oid spcOid)
Definition: relpath.c:110
bool rmtree(const char *path, bool rmtopdir)
Definition: rmtree.c:50
void ReplicationSlotsDropDBSlots(Oid dboid)
Definition: slot.c:1298
void ResolveRecoveryConflictWithDatabase(Oid dbid)
Definition: standby.c:568
#define stat
Definition: win32_port.h:284
#define S_ISDIR(m)
Definition: win32_port.h:325
#define XLogRecHasAnyBlockRefs(decoder)
Definition: xlogreader.h:417
void XLogDropDatabase(Oid dbid)
Definition: xlogutils.c:652
#define InHotStandby
Definition: xlogutils.h:60

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(), FATAL, FlushDatabaseBuffers(), ForgetDatabaseSyncRequests(), get_parent_directory(), GetDatabasePath(), i, InHotStandby, LockSharedObjectForSession(), xl_dbase_drop_rec::ntablespaces, PANIC, pfree(), PROCSIGNAL_BARRIER_SMGRRELEASE, pstrdup(), recovery_create_dbdir(), 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.