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first commit for openGauss server

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This commit is contained in:
lishifu
2020-06-30 17:38:27 +08:00
parent bcb52078d5
commit 815a9771fb
7975 changed files with 9646516 additions and 61 deletions
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985
src/common/backend/utils/cache/relmapper.cpp vendored Normal file
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/* -------------------------------------------------------------------------
*
* relmapper.c
* Catalog-to-filenode mapping
*
* For most tables, the physical file underlying the table is specified by
* pg_class.relfilenode. However, that obviously won't work for pg_class
* itself, nor for the other "nailed" catalogs for which we have to be able
* to set up working Relation entries without access to pg_class. It also
* does not work for shared catalogs, since there is no practical way to
* update other databases' pg_class entries when relocating a shared catalog.
* Therefore, for these special catalogs (henceforth referred to as "mapped
* catalogs") we rely on a separately maintained file that shows the mapping
* from catalog OIDs to filenode numbers. Each database has a map file for
* its local mapped catalogs, and there is a separate map file for shared
* catalogs. Mapped catalogs have zero in their pg_class.relfilenode entries.
*
* Relocation of a normal table is committed (ie, the new physical file becomes
* authoritative) when the pg_class row update commits. For mapped catalogs,
* the act of updating the map file is effectively commit of the relocation.
* We postpone the file update till just before commit of the transaction
* doing the rewrite, but there is necessarily a window between. Therefore
* mapped catalogs can only be relocated by operations such as VACUUM FULL
* and CLUSTER, which make no transactionally-significant changes: it must be
* safe for the new file to replace the old, even if the transaction itself
* aborts. An important factor here is that the indexes and toast table of
* a mapped catalog must also be mapped, so that the rewrites/relocations of
* all these files commit in a single map file update rather than being tied
* to transaction commit.
*
* Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* src/backend/utils/cache/relmapper.c
*
* -------------------------------------------------------------------------
*/
#include "postgres.h"
#include "knl/knl_variable.h"
#include <fcntl.h>
#include <sys/stat.h>
#include <unistd.h>
#include "access/xact.h"
#include "access/xlog.h"
#include "access/xloginsert.h"
#include "catalog/catalog.h"
#include "catalog/pg_tablespace.h"
#include "catalog/storage.h"
#include "miscadmin.h"
#include "storage/fd.h"
#include "storage/lwlock.h"
#include "utils/inval.h"
#include "utils/relmapper.h"
/* non-export function prototypes */
static void apply_map_update(RelMapFile* map, Oid relationId, Oid fileNode, bool add_okay);
static void merge_map_updates(RelMapFile* map, const RelMapFile* updates, bool add_okay);
static void load_relmap_file(bool shared);
static void recover_relmap_file(bool shared, bool backupfile);
static void write_relmap_file(bool shared, RelMapFile* newmap, bool write_wal, bool send_sinval, bool preserve_files,
Oid dbid, Oid tsid, const char* dbpath);
static void perform_relmap_update(bool shared, const RelMapFile* updates);
/*
* RelationMapOidToFilenode
*
* The raison d' etre ... given a relation OID, look up its filenode.
*
* Although shared and local relation OIDs should never overlap, the caller
* always knows which we need --- so pass that information to avoid useless
* searching.
*
* Returns InvalidOid if the OID is not known (which should never happen,
* but the caller is in a better position to report a meaningful error).
*/
Oid RelationMapOidToFilenode(Oid relationId, bool shared)
{
const RelMapFile* map = NULL;
int32 i;
/* If there are active updates, believe those over the main maps */
if (shared) {
map = u_sess->relmap_cxt.active_shared_updates;
for (i = 0; i < map->num_mappings; i++) {
if (relationId == map->mappings[i].mapoid) {
return map->mappings[i].mapfilenode;
}
}
map = u_sess->relmap_cxt.shared_map;
for (i = 0; i < map->num_mappings; i++) {
if (relationId == map->mappings[i].mapoid) {
return map->mappings[i].mapfilenode;
}
}
} else {
map = u_sess->relmap_cxt.active_local_updates;
for (i = 0; i < map->num_mappings; i++) {
if (relationId == map->mappings[i].mapoid) {
return map->mappings[i].mapfilenode;
}
}
map = u_sess->relmap_cxt.local_map;
for (i = 0; i < map->num_mappings; i++) {
if (relationId == map->mappings[i].mapoid) {
return map->mappings[i].mapfilenode;
}
}
}
return InvalidOid;
}
/*
* RelationMapFilenodeToOid
*
* Do the reverse of the normal direction of mapping done in
* RelationMapOidToFilenode.
*
* This is not supposed to be used during normal running but rather for
* information purposes when looking at the filesystem or xlog.
*
* Returns InvalidOid if the OID is not known; this can easily happen if the
* relfilenode doesn't pertain to a mapped relation.
*/
Oid RelationMapFilenodeToOid(Oid filenode, bool shared)
{
const RelMapFile* map = NULL;
int32 i;
/* If there are active updates, believe those over the main maps */
if (shared) {
map = u_sess->relmap_cxt.active_shared_updates;
for (i = 0; i < map->num_mappings; i++) {
if (filenode == map->mappings[i].mapfilenode) {
return map->mappings[i].mapoid;
}
}
map = u_sess->relmap_cxt.shared_map;
for (i = 0; i < map->num_mappings; i++) {
if (filenode == map->mappings[i].mapfilenode) {
return map->mappings[i].mapoid;
}
}
} else {
map = u_sess->relmap_cxt.active_local_updates;
for (i = 0; i < map->num_mappings; i++) {
if (filenode == map->mappings[i].mapfilenode) {
return map->mappings[i].mapoid;
}
}
map = u_sess->relmap_cxt.local_map;
for (i = 0; i < map->num_mappings; i++) {
if (filenode == map->mappings[i].mapfilenode) {
return map->mappings[i].mapoid;
}
}
}
return InvalidOid;
}
/*
* RelationMapUpdateMap
*
* Install a new relfilenode mapping for the specified relation.
*
* If immediate is true (or we're bootstrapping), the mapping is activated
* immediately. Otherwise it is made pending until CommandCounterIncrement.
*/
void RelationMapUpdateMap(Oid relationId, Oid fileNode, bool shared, bool immediate)
{
RelMapFile* map = NULL;
if (IsBootstrapProcessingMode()) {
/*
* In bootstrap mode, the mapping gets installed in permanent map.
*/
if (shared) {
map = u_sess->relmap_cxt.shared_map;
} else {
map = u_sess->relmap_cxt.local_map;
}
} else {
/*
* We don't currently support map changes within subtransactions. This
* could be done with more bookkeeping infrastructure, but it doesn't
* presently seem worth it.
*/
if (GetCurrentTransactionNestLevel() > 1) {
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot change relation mapping within subtransaction")));
}
if (immediate) {
/* Make it active, but only locally */
if (shared) {
map = u_sess->relmap_cxt.active_shared_updates;
} else {
map = u_sess->relmap_cxt.active_local_updates;
}
} else {
/* Make it pending */
if (shared) {
map = u_sess->relmap_cxt.pending_shared_updates;
} else {
map = u_sess->relmap_cxt.pending_local_updates;
}
}
}
apply_map_update(map, relationId, fileNode, true);
}
/*
* apply_map_update
*
* Insert a new mapping into the given map variable, replacing any existing
* mapping for the same relation.
*
* In some cases the caller knows there must be an existing mapping; pass
* add_okay = false to draw an error if not.
*/
static void apply_map_update(RelMapFile* map, Oid relationId, Oid fileNode, bool add_okay)
{
int32 i;
/* Replace any existing mapping */
for (i = 0; i < map->num_mappings; i++) {
if (relationId == map->mappings[i].mapoid) {
map->mappings[i].mapfilenode = fileNode;
return;
}
}
/* Nope, need to add a new mapping */
if (!add_okay) {
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("attempt to apply a mapping to unmapped relation %u", relationId)));
}
if (map->num_mappings >= MAX_MAPPINGS) {
ereport(ERROR, (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED), errmsg("ran out of space in relation map")));
}
map->mappings[map->num_mappings].mapoid = relationId;
map->mappings[map->num_mappings].mapfilenode = fileNode;
map->num_mappings++;
}
/*
* merge_map_updates
*
* Merge all the updates in the given pending-update map into the target map.
* This is just a bulk form of apply_map_update.
*/
static void merge_map_updates(RelMapFile* map, const RelMapFile* updates, bool add_okay)
{
int32 i;
for (i = 0; i < updates->num_mappings; i++) {
apply_map_update(map, updates->mappings[i].mapoid, updates->mappings[i].mapfilenode, add_okay);
}
}
/*
* RelationMapRemoveMapping
*
* Remove a relation's entry in the map. This is only allowed for "active"
* (but not committed) local mappings. We need it so we can back out the
* entry for the transient target file when doing VACUUM FULL/CLUSTER on
* a mapped relation.
*/
void RelationMapRemoveMapping(Oid relationId)
{
RelMapFile* map = u_sess->relmap_cxt.active_local_updates;
int32 i;
for (i = 0; i < map->num_mappings; i++) {
if (relationId == map->mappings[i].mapoid) {
/* Found it, collapse it out */
map->mappings[i] = map->mappings[map->num_mappings - 1];
map->num_mappings--;
return;
}
}
ereport(ERROR,
(errcode(ERRCODE_NO_DATA_FOUND), errmsg("could not find temporary mapping for relation %u", relationId)));
}
/*
* RelationMapInvalidate
*
* This routine is invoked for SI cache flush messages. We must re-read
* the indicated map file. However, we might receive a SI message in a
* process that hasn't yet, and might never, load the mapping files;
* for example the autovacuum launcher, which *must not* try to read
* a local map since it is attached to no particular database.
* So, re-read only if the map is valid now.
*/
void RelationMapInvalidate(bool shared)
{
if (shared) {
if (u_sess->relmap_cxt.shared_map->magic == RELMAPPER_FILEMAGIC) {
LWLockAcquire(RelationMappingLock, LW_SHARED);
load_relmap_file(true);
LWLockRelease(RelationMappingLock);
}
} else {
if (u_sess->relmap_cxt.local_map->magic == RELMAPPER_FILEMAGIC) {
LWLockAcquire(RelationMappingLock, LW_SHARED);
load_relmap_file(false);
LWLockRelease(RelationMappingLock);
}
}
}
/*
* RelationMapInvalidateAll
*
* Reload all map files. This is used to recover from SI message buffer
* overflow: we can't be sure if we missed an inval message.
* Again, reload only currently-valid maps.
*/
void RelationMapInvalidateAll(void)
{
LWLockAcquire(RelationMappingLock, LW_SHARED);
if (u_sess->relmap_cxt.shared_map->magic == RELMAPPER_FILEMAGIC) {
load_relmap_file(true);
}
if (u_sess->relmap_cxt.local_map->magic == RELMAPPER_FILEMAGIC) {
load_relmap_file(false);
}
LWLockRelease(RelationMappingLock);
}
/*
* AtCCI_RelationMap
*
* Activate any "pending" relation map updates at CommandCounterIncrement time.
*/
void AtCCI_RelationMap(void)
{
if (u_sess->relmap_cxt.pending_shared_updates->num_mappings != 0) {
merge_map_updates(u_sess->relmap_cxt.active_shared_updates, u_sess->relmap_cxt.pending_shared_updates, true);
u_sess->relmap_cxt.pending_shared_updates->num_mappings = 0;
}
if (u_sess->relmap_cxt.pending_local_updates->num_mappings != 0) {
merge_map_updates(u_sess->relmap_cxt.active_local_updates, u_sess->relmap_cxt.pending_local_updates, true);
u_sess->relmap_cxt.pending_local_updates->num_mappings = 0;
}
}
/*
* AtEOXact_RelationMap
*
* Handle relation mapping at main-transaction commit or abort.
*
* During commit, this must be called as late as possible before the actual
* transaction commit, so as to minimize the window where the transaction
* could still roll back after committing map changes. Although nothing
* critically bad happens in such a case, we still would prefer that it
* not happen, since we'd possibly be losing useful updates to the relations'
* pg_class row(s).
*
* During abort, we just have to throw away any pending map changes.
* Normal post-abort cleanup will take care of fixing relcache entries.
*/
void AtEOXact_RelationMap(bool isCommit)
{
if (isCommit) {
/*
* We should not get here with any "pending" updates. (We could
* logically choose to treat such as committed, but in the current
* code this should never happen.)
*/
Assert(u_sess->relmap_cxt.pending_shared_updates->num_mappings == 0);
Assert(u_sess->relmap_cxt.pending_local_updates->num_mappings == 0);
/*
* Write any active updates to the actual map files, then reset them.
*/
if (u_sess->relmap_cxt.active_shared_updates->num_mappings != 0) {
perform_relmap_update(true, u_sess->relmap_cxt.active_shared_updates);
u_sess->relmap_cxt.active_shared_updates->num_mappings = 0;
}
if (u_sess->relmap_cxt.active_local_updates->num_mappings != 0) {
perform_relmap_update(false, u_sess->relmap_cxt.active_local_updates);
u_sess->relmap_cxt.active_local_updates->num_mappings = 0;
}
} else {
/* Abort --- drop all local and pending updates */
u_sess->relmap_cxt.active_shared_updates->num_mappings = 0;
u_sess->relmap_cxt.active_local_updates->num_mappings = 0;
u_sess->relmap_cxt.pending_shared_updates->num_mappings = 0;
u_sess->relmap_cxt.pending_local_updates->num_mappings = 0;
}
}
/*
* AtPrepare_RelationMap
*
* Handle relation mapping at PREPARE.
*
* Currently, we don't support preparing any transaction that changes the map.
*/
void AtPrepare_RelationMap(void)
{
if (u_sess->attr.attr_common.IsInplaceUpgrade) {
return;
}
if (u_sess->relmap_cxt.active_shared_updates->num_mappings != 0 ||
u_sess->relmap_cxt.active_local_updates->num_mappings != 0 ||
u_sess->relmap_cxt.pending_shared_updates->num_mappings != 0 ||
u_sess->relmap_cxt.pending_local_updates->num_mappings != 0) {
ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot PREPARE a transaction that modified relation mapping")));
}
}
/*
* CheckPointRelationMap
*
* This is called during a checkpoint. It must ensure that any relation map
* updates that were WAL-logged before the start of the checkpoint are
* securely flushed to disk and will not need to be replayed later. This
* seems unlikely to be a performance-critical issue, so we use a simple
* method: we just take and release the RelationMappingLock. This ensures
* that any already-logged map update is complete, because write_relmap_file
* will fsync the map file before the lock is released.
*/
void CheckPointRelationMap(void)
{
LWLockAcquire(RelationMappingLock, LW_SHARED);
LWLockRelease(RelationMappingLock);
}
/*
* RelationMapFinishBootstrap
*
* Write out the initial relation mapping files at the completion of
* bootstrap. All the mapped files should have been made known to us
* via RelationMapUpdateMap calls.
*/
void RelationMapFinishBootstrap(void)
{
Assert(IsBootstrapProcessingMode());
/* Shouldn't be anything "pending" ... */
Assert(u_sess->relmap_cxt.active_shared_updates->num_mappings == 0);
Assert(u_sess->relmap_cxt.active_local_updates->num_mappings == 0);
Assert(u_sess->relmap_cxt.pending_shared_updates->num_mappings == 0);
Assert(u_sess->relmap_cxt.pending_local_updates->num_mappings == 0);
/* Write the files; no WAL or sinval needed */
write_relmap_file(true, u_sess->relmap_cxt.shared_map, false, false, false, InvalidOid, GLOBALTABLESPACE_OID, NULL);
write_relmap_file(false,
u_sess->relmap_cxt.local_map,
false,
false,
false,
u_sess->proc_cxt.MyDatabaseId,
u_sess->proc_cxt.MyDatabaseTableSpace,
u_sess->proc_cxt.DatabasePath);
}
/*
* RelationMapInitialize
*
* This initializes the mapper module at process startup. We can't access the
* database yet, so just make sure the maps are empty.
*/
void RelationMapInitialize(void)
{
/* The static variables should initialize to zeroes, but let's be sure */
u_sess->relmap_cxt.shared_map->magic = 0; /* mark it not loaded */
u_sess->relmap_cxt.local_map->magic = 0;
u_sess->relmap_cxt.shared_map->num_mappings = 0;
u_sess->relmap_cxt.local_map->num_mappings = 0;
u_sess->relmap_cxt.active_shared_updates->num_mappings = 0;
u_sess->relmap_cxt.active_local_updates->num_mappings = 0;
u_sess->relmap_cxt.pending_shared_updates->num_mappings = 0;
u_sess->relmap_cxt.pending_local_updates->num_mappings = 0;
}
/*
* RelationMapInitializePhase2
*
* This is called to prepare for access to pg_database during startup.
* We should be able to read the shared map file now.
*/
void RelationMapInitializePhase2(void)
{
/*
* In bootstrap mode, the map file isn't there yet, so do nothing.
*/
if (IsBootstrapProcessingMode()) {
return;
}
/*
* Load the shared map file, die on error.
*/
LWLockAcquire(RelationMappingLock, LW_SHARED);
load_relmap_file(true);
LWLockRelease(RelationMappingLock);
}
/*
* RelationMapInitializePhase3
*
* This is called as soon as we have determined u_sess->proc_cxt.MyDatabaseId and set up
* u_sess->proc_cxt.DatabasePath. At this point we should be able to read the local map file.
*/
void RelationMapInitializePhase3(void)
{
/*
* In bootstrap mode, the map file isn't there yet, so do nothing.
*/
if (IsBootstrapProcessingMode()) {
return;
}
/*
* Load the local map file, die on error.
*/
LWLockAcquire(RelationMappingLock, LW_SHARED);
load_relmap_file(false);
LWLockRelease(RelationMappingLock);
}
/*
* load_relmap_file -- load data from the shared or local map file
*
* Because the map file is essential for access to core system catalogs,
* failure to read it is a fatal error.
*
* Note that the local case requires u_sess->proc_cxt.DatabasePath to be set up.
*/
static void load_relmap_file(bool shared)
{
RelMapFile* map = NULL;
char map_file_name[2][MAXPGPATH];
char* file_name = NULL;
pg_crc32 crc;
int fd;
bool fix_backup = false;
bool retry = false;
struct stat stat_buf;
errno_t rc;
if (shared) {
rc = snprintf_s(
map_file_name[0], sizeof(map_file_name[0]), sizeof(map_file_name[0]) - 1, "global/%s", RELMAPPER_FILENAME);
securec_check_ss(rc, "\0", "\0");
rc = snprintf_s(map_file_name[1], sizeof(map_file_name[1]), sizeof(map_file_name[1]) - 1, "global/%s",
RELMAPPER_FILENAME_BAK);
securec_check_ss(rc, "\0", "\0");
map = u_sess->relmap_cxt.shared_map;
} else {
rc = snprintf_s(map_file_name[0],
sizeof(map_file_name[0]),
sizeof(map_file_name[0]) - 1,
"%s/%s",
u_sess->proc_cxt.DatabasePath,
RELMAPPER_FILENAME);
securec_check_ss(rc, "\0", "\0");
rc = snprintf_s(map_file_name[1],
sizeof(map_file_name[1]),
sizeof(map_file_name[1]) - 1,
"%s/%s",
u_sess->proc_cxt.DatabasePath,
RELMAPPER_FILENAME_BAK);
securec_check_ss(rc, "\0", "\0");
map = u_sess->relmap_cxt.local_map;
}
// check backup file
if (stat(map_file_name[1], &stat_buf) != 0) {
if (ENOENT != errno) {
ereport(LOG, (errmsg("can not stat file \"%s\", ignore backup file", map_file_name[1])));
}
else {
fix_backup = true;
// switch to exclusive lock to do backup map file recovery
LWLockRelease(RelationMappingLock);
LWLockAcquire(RelationMappingLock, LW_EXCLUSIVE);
}
}
file_name = map_file_name[0];
loop:
/* Read data ... */
fd = BasicOpenFile(file_name, O_RDONLY | PG_BINARY, S_IRUSR | S_IWUSR);
if (fd < 0) {
ereport(
FATAL, (errcode_for_file_access(), errmsg("could not open relation mapping file \"%s\": %m", file_name)));
}
/*
* Note: we take RelationMappingLock in shared mode here, because it
* seems that read() may not be atomic against any
* concurrent updater's write(). If the file is updated shortly after we
* look, the sinval signaling mechanism will make us re-read it before we
* are able to access any relation that's affected by the change.
*/
if (read(fd, map, sizeof(RelMapFile)) != sizeof(RelMapFile)) {
close(fd);
ereport(
FATAL, (errcode_for_file_access(), errmsg("could not read relation mapping file \"%s\": %m", file_name)));
}
if (close(fd)) {
ereport(PANIC, (errcode_for_file_access(), errmsg("could not close control file: %m")));
}
/* verify the CRC */
INIT_CRC32(crc);
COMP_CRC32(crc, (char*)map, offsetof(RelMapFile, crc));
FIN_CRC32(crc);
if (!EQ_CRC32(crc, (pg_crc32)(map->crc))) {
if (retry == false) {
ereport(WARNING,
(errmsg("relation mapping file \"%s\" contains incorrect checksum, try backup file", file_name)));
file_name = map_file_name[1];
retry = true;
if (fix_backup == false) {
// switch to exclusive lock to do map file recovery
LWLockRelease(RelationMappingLock);
LWLockAcquire(RelationMappingLock, LW_EXCLUSIVE);
}
goto loop;
} else {
ereport(FATAL, (errmsg("relation mapping file \"%s\" contains incorrect checksum", file_name)));
}
}
// check for correct magic number, etc
if (map->magic != RELMAPPER_FILEMAGIC || map->num_mappings < 0 || map->num_mappings > MAX_MAPPINGS) {
ereport(FATAL, (errmsg("relation mapping file \"%s\" contains invalid data", file_name)));
}
if (retry == true) {
recover_relmap_file(shared, false);
} else if (fix_backup == true) {
recover_relmap_file(shared, true);
}
}
/*
* Write out a new shared or local map file with the given contents.
*
* The magic number and CRC are automatically updated in *newmap. On
* success, we copy the data to the appropriate permanent static variable.
*
* If write_wal is TRUE then an appropriate WAL message is emitted.
* (It will be false for bootstrap and WAL replay cases.)
*
* If send_sinval is TRUE then a SI invalidation message is sent.
* (This should be true except in bootstrap case.)
*
* If preserve_files is TRUE then the storage manager is warned not to
* delete the files listed in the map.
*
* Because this may be called during WAL replay when u_sess->proc_cxt.MyDatabaseId,
* u_sess->proc_cxt.DatabasePath, etc aren't valid, we require the caller to pass in suitable
* values. The caller is also responsible for being sure no concurrent
* map update could be happening.
*/
static void write_relmap_file(bool shared, RelMapFile* newmap, bool write_wal, bool send_sinval, bool preserve_files,
Oid dbid, Oid tsid, const char* dbpath)
{
int fd;
RelMapFile* real_map = NULL;
char map_file_name[MAXPGPATH];
errno_t rc = 0;
char* fname[2];
/*
* Fill in the overhead fields and update CRC.
*/
newmap->magic = RELMAPPER_FILEMAGIC;
if (newmap->num_mappings < 0 || newmap->num_mappings > MAX_MAPPINGS) {
ereport(
ERROR, (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE), errmsg("attempt to write bogus relation mapping")));
}
INIT_CRC32(newmap->crc);
COMP_CRC32(newmap->crc, (char*)newmap, offsetof(RelMapFile, crc));
FIN_CRC32(newmap->crc);
/*
* Open the target file. We prefer to do this before entering the
* critical section, so that an open() failure need not force PANIC.
*
* Note: since we use BasicOpenFile, we are nominally responsible for
* ensuring the fd is closed on error. In practice, this isn't important
* because either an error happens inside the critical section, or we are
* in bootstrap or WAL replay; so an error past this point is always fatal
* anyway.
*/
fname[0] = RELMAPPER_FILENAME_BAK;
fname[1] = RELMAPPER_FILENAME;
for (int i = 0; i < 2; i++) {
if (shared) {
rc = snprintf_s(map_file_name, sizeof(map_file_name), sizeof(map_file_name) - 1, "global/%s", fname[i]);
securec_check_ss_c(rc, "\0", "\0");
real_map = u_sess->relmap_cxt.shared_map;
} else {
rc = snprintf_s(map_file_name, sizeof(map_file_name), sizeof(map_file_name) - 1, "%s/%s", dbpath, fname[i]);
securec_check_ss_c(rc, "\0", "\0");
real_map = u_sess->relmap_cxt.local_map;
}
fd = BasicOpenFile(map_file_name, O_WRONLY | O_CREAT | PG_BINARY, S_IRUSR | S_IWUSR);
if (fd < 0) {
ereport(ERROR,
(errcode_for_file_access(), errmsg("could not open relation mapping file \"%s\": %m", map_file_name)));
}
if (write_wal && (i == 0)) {
xl_relmap_update xlrec;
XLogRecPtr lsn;
/* now errors are fatal ... */
START_CRIT_SECTION();
xlrec.dbid = dbid;
xlrec.tsid = tsid;
xlrec.nbytes = sizeof(RelMapFile);
XLogBeginInsert();
XLogRegisterData((char*)(&xlrec), MinSizeOfRelmapUpdate);
XLogRegisterData((char*)newmap, sizeof(RelMapFile));
lsn = XLogInsert(RM_RELMAP_ID, XLOG_RELMAP_UPDATE);
/* As always, WAL must hit the disk before the data update does */
XLogFlush(lsn);
}
errno = 0;
if (write(fd, newmap, sizeof(RelMapFile)) != sizeof(RelMapFile)) {
close(fd);
/* if write didn't set errno, assume problem is no disk space */
if (errno == 0) {
errno = ENOSPC;
}
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not write to relation mapping file \"%s\": %m", map_file_name)));
}
/*
* We choose to fsync the data to disk before considering the task done.
* It would be possible to relax this if it turns out to be a performance
* issue, but it would complicate checkpointing --- see notes for
* CheckPointRelationMap.
*/
if (pg_fsync(fd) != 0) {
close(fd);
ereport(data_sync_elevel(ERROR),
(errcode_for_file_access(), errmsg("could not fsync relation mapping file \"%s\": %m", map_file_name)));
}
if (close(fd)) {
ereport(ERROR,
(errcode_for_file_access(), errmsg("could not close relation mapping file \"%s\": %m", map_file_name)));
}
}
/*
* Now that the file is safely on disk, send sinval message to let other
* backends know to re-read it. We must do this inside the critical
* section: if for some reason we fail to send the message, we have to
* force a database-wide PANIC. Otherwise other backends might continue
* execution with stale mapping information, which would be catastrophic
* as soon as others began to use the now-committed data.
*/
if (send_sinval) {
CacheInvalidateRelmap(dbid);
}
/*
* Make sure that the files listed in the map are not deleted if the outer
* transaction aborts. This had better be within the critical section
* too: it's not likely to fail, but if it did, we'd arrive at transaction
* abort with the files still vulnerable. PANICing will leave things in a
* good state on-disk.
*
* Note: we're cheating a little bit here by assuming that mapped files
* are either in pg_global or the database's default tablespace.
*/
if (preserve_files) {
int32 i;
for (i = 0; i < newmap->num_mappings; i++) {
RelFileNode rnode;
rnode.spcNode = tsid;
rnode.dbNode = dbid;
rnode.relNode = newmap->mappings[i].mapfilenode;
RelationPreserveStorage(rnode, false);
}
}
/* Success, update permanent copy */
rc = memcpy_s(real_map, sizeof(RelMapFile), newmap, sizeof(RelMapFile));
securec_check(rc, "", "");
/* Critical section done */
if (write_wal) {
END_CRIT_SECTION();
}
}
/*
* Merge the specified updates into the appropriate "real" map,
* and write out the changes. This function must be used for committing
* updates during normal multiuser operation.
*/
static void perform_relmap_update(bool shared, const RelMapFile* updates)
{
RelMapFile new_map;
errno_t rc;
/*
* Anyone updating a relation's mapping info should take exclusive lock on
* that rel and hold it until commit. This ensures that there will not be
* concurrent updates on the same mapping value; but there could easily be
* concurrent updates on different values in the same file. We cover that
* by acquiring the RelationMappingLock, re-reading the target file to
* ensure it's up to date, applying the updates, and writing the data
* before releasing RelationMappingLock.
*
* There is only one RelationMappingLock. In principle we could try to
* have one per mapping file, but it seems unlikely to be worth the
* trouble.
*/
LWLockAcquire(RelationMappingLock, LW_EXCLUSIVE);
/* Be certain we see any other updates just made */
load_relmap_file(shared);
/* Prepare updated data in a local variable */
if (shared) {
rc = memcpy_s(&new_map, sizeof(RelMapFile), u_sess->relmap_cxt.shared_map, sizeof(RelMapFile));
securec_check(rc, "", "");
} else {
rc = memcpy_s(&new_map, sizeof(RelMapFile), u_sess->relmap_cxt.local_map, sizeof(RelMapFile));
securec_check(rc, "", "");
}
/*
* Apply the updates to newmap. No new mappings should appear, unless
* somebody is adding indexes to system catalogs.
*/
merge_map_updates(&new_map,
updates,
(g_instance.attr.attr_common.allowSystemTableMods || u_sess->attr.attr_common.IsInplaceUpgrade));
/* Write out the updated map and do other necessary tasks */
write_relmap_file(shared,
&new_map,
true,
true,
true,
(shared ? InvalidOid : u_sess->proc_cxt.MyDatabaseId),
(shared ? GLOBALTABLESPACE_OID : u_sess->proc_cxt.MyDatabaseTableSpace),
u_sess->proc_cxt.DatabasePath);
/* Now we can release the lock */
LWLockRelease(RelationMappingLock);
}
/*
* when incorrect checksum is detected in relation map file,
* we should recover the file using the content of backup file or,
* if there is no backup file, we create it immediately.
*/
static void recover_relmap_file(bool shared, bool backupfile)
{
int fd;
RelMapFile* real_map = NULL;
char map_file_name[MAXPGPATH];
char* file_name = NULL;
int level;
errno_t rc;
if (backupfile) {
file_name = RELMAPPER_FILENAME_BAK;
level = LOG;
} else {
file_name = RELMAPPER_FILENAME;
level = WARNING;
}
if (shared) {
rc = snprintf_s(map_file_name, sizeof(map_file_name), sizeof(map_file_name) - 1, "global/%s", file_name);
securec_check_ss(rc, "\0", "\0");
real_map = u_sess->relmap_cxt.shared_map;
} else {
rc = snprintf_s(map_file_name,
sizeof(map_file_name),
sizeof(map_file_name) - 1,
"%s/%s",
u_sess->proc_cxt.DatabasePath,
file_name);
securec_check_ss(rc, "\0", "\0");
real_map = u_sess->relmap_cxt.local_map;
}
ereport(level, (errmsg("recover the relation mapping file %s", map_file_name)));
fd = BasicOpenFile(map_file_name, O_CREAT | O_TRUNC | O_WRONLY | PG_BINARY, S_IRUSR | S_IWUSR);
if (fd < 0) {
ereport(ERROR, (errcode_for_file_access(), errmsg("could not open relation mapping file \"%s\": %m",
map_file_name)));
}
errno = 0;
if (write(fd, real_map, sizeof(RelMapFile)) != sizeof(RelMapFile)) {
/* if write didn't set errno, assume problem is no disk space */
if (errno == 0) {
errno = ENOSPC;
}
ereport(PANIC,
(errcode_for_file_access(),
errmsg("recover failed could not write to relation mapping file \"%s\": %m", map_file_name)));
}
if (pg_fsync(fd) != 0) {
ereport(PANIC,
(errcode_for_file_access(),
errmsg("recover failed could not fsync relation mapping file \"%s\": %m", map_file_name)));
}
if (close(fd)) {
ereport(ERROR,
(errcode_for_file_access(),
errmsg("recover failed could not close relation mapping file \"%s\": %m", map_file_name)));
}
}
/*
* RELMAP resource manager's routines
*/
void relmap_redo(XLogReaderState* record)
{
uint8 info = XLogRecGetInfo(record) & ~XLR_INFO_MASK;
/* Backup blocks are not used in relmap records */
Assert(!XLogRecHasAnyBlockRefs(record));
if (info == XLOG_RELMAP_UPDATE) {
xl_relmap_update* xlrec = (xl_relmap_update*)XLogRecGetData(record);
RelMapFile new_map;
char* dbpath = NULL;
errno_t rc;
if (xlrec->nbytes != sizeof(RelMapFile)) {
ereport(PANIC,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("relmap_redo: wrong size %d in relmap update record", xlrec->nbytes)));
}
rc = memcpy_s(&new_map, sizeof(new_map), xlrec->data, sizeof(new_map));
securec_check(rc, "\0", "\0");
/* We need to construct the pathname for this database */
dbpath = GetDatabasePath(xlrec->dbid, xlrec->tsid);
/*
* Write out the new map and send sinval, but of course don't write a
* new WAL entry. There's no surrounding transaction to tell to
* preserve files, either.
*
* There shouldn't be anyone else updating relmaps during WAL replay,
* so we don't bother to take the RelationMappingLock. We would need
* to do so if load_relmap_file needed to interlock against writers.
*/
XLogRecPtr lsn = record->EndRecPtr;
UpdateMinRecoveryPoint(lsn, false);
write_relmap_file((xlrec->dbid == InvalidOid), &new_map, false, true, false, xlrec->dbid, xlrec->tsid, dbpath);
pfree_ext(dbpath);
} else {
ereport(PANIC, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("relmap_redo: unknown op code %u", info)));
}
}