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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 *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:491
#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:73
void appendStringInfo(StringInfo str, const char *fmt,...)
Definition: stringinfo.c:97
void appendStringInfoString(StringInfo str, const char *s)
Definition: stringinfo.c:182
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 3184 of file dbcommands.c.

3185 {
3186  uint8 info = XLogRecGetInfo(record) & ~XLR_INFO_MASK;
3187 
3188  /* Backup blocks are not used in dbase records */
3189  Assert(!XLogRecHasAnyBlockRefs(record));
3190 
3191  if (info == XLOG_DBASE_CREATE_FILE_COPY)
3192  {
3195  char *src_path;
3196  char *dst_path;
3197  char *parent_path;
3198  struct stat st;
3199 
3200  src_path = GetDatabasePath(xlrec->src_db_id, xlrec->src_tablespace_id);
3201  dst_path = GetDatabasePath(xlrec->db_id, xlrec->tablespace_id);
3202 
3203  /*
3204  * Our theory for replaying a CREATE is to forcibly drop the target
3205  * subdirectory if present, then re-copy the source data. This may be
3206  * more work than needed, but it is simple to implement.
3207  */
3208  if (stat(dst_path, &st) == 0 && S_ISDIR(st.st_mode))
3209  {
3210  if (!rmtree(dst_path, true))
3211  /* If this failed, copydir() below is going to error. */
3212  ereport(WARNING,
3213  (errmsg("some useless files may be left behind in old database directory \"%s\"",
3214  dst_path)));
3215  }
3216 
3217  /*
3218  * If the parent of the target path doesn't exist, create it now. This
3219  * enables us to create the target underneath later.
3220  */
3221  parent_path = pstrdup(dst_path);
3222  get_parent_directory(parent_path);
3223  if (stat(parent_path, &st) < 0)
3224  {
3225  if (errno != ENOENT)
3226  ereport(FATAL,
3227  errmsg("could not stat directory \"%s\": %m",
3228  dst_path));
3229 
3230  /* create the parent directory if needed and valid */
3231  recovery_create_dbdir(parent_path, true);
3232  }
3233  pfree(parent_path);
3234 
3235  /*
3236  * There's a case where the copy source directory is missing for the
3237  * same reason above. Create the empty source directory so that
3238  * copydir below doesn't fail. The directory will be dropped soon by
3239  * recovery.
3240  */
3241  if (stat(src_path, &st) < 0 && errno == ENOENT)
3242  recovery_create_dbdir(src_path, false);
3243 
3244  /*
3245  * Force dirty buffers out to disk, to ensure source database is
3246  * up-to-date for the copy.
3247  */
3249 
3250  /* Close all sgmr fds in all backends. */
3252 
3253  /*
3254  * Copy this subdirectory to the new location
3255  *
3256  * We don't need to copy subdirectories
3257  */
3258  copydir(src_path, dst_path, false);
3259 
3260  pfree(src_path);
3261  pfree(dst_path);
3262  }
3263  else if (info == XLOG_DBASE_CREATE_WAL_LOG)
3264  {
3267  char *dbpath;
3268  char *parent_path;
3269 
3270  dbpath = GetDatabasePath(xlrec->db_id, xlrec->tablespace_id);
3271 
3272  /* create the parent directory if needed and valid */
3273  parent_path = pstrdup(dbpath);
3274  get_parent_directory(parent_path);
3275  recovery_create_dbdir(parent_path, true);
3276 
3277  /* Create the database directory with the version file. */
3278  CreateDirAndVersionFile(dbpath, xlrec->db_id, xlrec->tablespace_id,
3279  true);
3280  pfree(dbpath);
3281  }
3282  else if (info == XLOG_DBASE_DROP)
3283  {
3284  xl_dbase_drop_rec *xlrec = (xl_dbase_drop_rec *) XLogRecGetData(record);
3285  char *dst_path;
3286  int i;
3287 
3288  if (InHotStandby)
3289  {
3290  /*
3291  * Lock database while we resolve conflicts to ensure that
3292  * InitPostgres() cannot fully re-execute concurrently. This
3293  * avoids backends re-connecting automatically to same database,
3294  * which can happen in some cases.
3295  *
3296  * This will lock out walsenders trying to connect to db-specific
3297  * slots for logical decoding too, so it's safe for us to drop
3298  * slots.
3299  */
3300  LockSharedObjectForSession(DatabaseRelationId, xlrec->db_id, 0, AccessExclusiveLock);
3302  }
3303 
3304  /* Drop any database-specific replication slots */
3306 
3307  /* Drop pages for this database that are in the shared buffer cache */
3308  DropDatabaseBuffers(xlrec->db_id);
3309 
3310  /* Also, clean out any fsync requests that might be pending in md.c */
3312 
3313  /* Clean out the xlog relcache too */
3314  XLogDropDatabase(xlrec->db_id);
3315 
3316  /* Close all sgmr fds in all backends. */
3318 
3319  for (i = 0; i < xlrec->ntablespaces; i++)
3320  {
3321  dst_path = GetDatabasePath(xlrec->db_id, xlrec->tablespace_ids[i]);
3322 
3323  /* And remove the physical files */
3324  if (!rmtree(dst_path, true))
3325  ereport(WARNING,
3326  (errmsg("some useless files may be left behind in old database directory \"%s\"",
3327  dst_path)));
3328  pfree(dst_path);
3329  }
3330 
3331  if (InHotStandby)
3332  {
3333  /*
3334  * Release locks prior to commit. XXX There is a race condition
3335  * here that may allow backends to reconnect, but the window for
3336  * this is small because the gap between here and commit is mostly
3337  * fairly small and it is unlikely that people will be dropping
3338  * databases that we are trying to connect to anyway.
3339  */
3340  UnlockSharedObjectForSession(DatabaseRelationId, xlrec->db_id, 0, AccessExclusiveLock);
3341  }
3342  }
3343  else
3344  elog(PANIC, "dbase_redo: unknown op code %u", info);
3345 }
void DropDatabaseBuffers(Oid dbid)
Definition: bufmgr.c:4039
void FlushDatabaseBuffers(Oid dbid)
Definition: bufmgr.c:4498
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:3155
int errmsg(const char *fmt,...)
Definition: elog.c:1072
#define FATAL
Definition: elog.h:41
#define WARNING
Definition: elog.h:36
#define PANIC
Definition: elog.h:42
#define elog(elevel,...)
Definition: elog.h:224
#define ereport(elevel,...)
Definition: elog.h:149
Assert(fmt[strlen(fmt) - 1] !='\n')
void UnlockSharedObjectForSession(Oid classid, Oid objid, uint16 objsubid, LOCKMODE lockmode)
Definition: lmgr.c:1143
void LockSharedObjectForSession(Oid classid, Oid objid, uint16 objsubid, LOCKMODE lockmode)
Definition: lmgr.c:1125
#define AccessExclusiveLock
Definition: lockdefs.h:43
char * pstrdup(const char *in)
Definition: mcxt.c:1576
void pfree(void *pointer)
Definition: mcxt.c:1401
void ForgetDatabaseSyncRequests(Oid dbid)
Definition: md.c:1428
void get_parent_directory(char *path)
Definition: path.c:977
void WaitForProcSignalBarrier(uint64 generation)
Definition: procsignal.c:389
uint64 EmitProcSignalBarrier(ProcSignalBarrierType type)
Definition: procsignal.c:329
@ 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:1206
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: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(), 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.