/*
* RelationCreateStorage
* Create physical storage for a relation.
*
* Create the underlying disk file storage for the relation. This only
* creates the main fork; additional forks are created lazily by the
* modules that need them.
*
* This function is transactional. The creation is WAL-logged, and if the
* transaction aborts later on, the storage will be destroyed.
*/
void
RelationCreateStorage(RelFileNode rnode, bool istemp)
{
PendingRelDelete *pending;
XLogRecPtr lsn;
XLogRecData rdata;
xl_smgr_create xlrec;
SMgrRelation srel;
srel = smgropen(rnode);
smgrcreate(srel, MAIN_FORKNUM, false);
if (!istemp)
{
/*
* Make an XLOG entry showing the file creation. If we abort, the
* file will be dropped at abort time.
*/
xlrec.rnode = rnode;
rdata.data = (char *) &xlrec;
rdata.len = sizeof(xlrec);
rdata.buffer = InvalidBuffer;
rdata.next = NULL;
lsn = XLogInsert(RM_SMGR_ID, XLOG_SMGR_CREATE, &rdata);
}
/* Add the relation to the list of stuff to delete at abort */
pending = (PendingRelDelete *)
MemoryContextAlloc(TopMemoryContext, sizeof(PendingRelDelete));
pending->relnode = rnode;
pending->isTemp = istemp;
pending->atCommit = false; /* delete if abort */
pending->nestLevel = GetCurrentTransactionNestLevel();
pending->next = pendingDeletes;
pendingDeletes = pending;
}
static int
FileRepPrimary_ResyncBufferPoolIncrementalWrite(ChangeTrackingRequest *request)
{
int status = STATUS_OK;
Page page;
Buffer buf;
BlockNumber numBlocks = 0;
SMgrRelation smgr_relation = NULL;
char relidstr[OIDCHARS + 1 + OIDCHARS + 1 + OIDCHARS + 1];
int ii;
XLogRecPtr loc;
XLogRecPtr loc1;
int count = 0;
int thresholdCount = 0;
bool mirrorDataLossOccurred = FALSE;
int NumberOfRelations = request->count;
FileRepResyncHashEntry_s entry;
ChangeTrackingResult *result = NULL;
while (1)
{
/* allow flushing buffers from buffer pool during scan */
FileRepResync_SetReadBufferRequest();
if ((result = ChangeTracking_GetChanges(request)) != NULL)
{
FileRepResync_ResetReadBufferRequest();
for (ii = 0; ii < result->count; ii++)
{
if (smgr_relation == NULL)
{
NumberOfRelations--;
smgr_relation = smgropen(result->entries[ii].relFileNode);
snprintf(relidstr, sizeof(relidstr), "%u/%u/%u",
smgr_relation->smgr_rnode.spcNode,
smgr_relation->smgr_rnode.dbNode,
smgr_relation->smgr_rnode.relNode);
numBlocks = smgrnblocks(smgr_relation);
if (Debug_filerep_print)
elog(LOG, "resynchronize buffer pool relation '%u/%u/%u' "
"number of blocks:'%u' ",
smgr_relation->smgr_rnode.spcNode,
smgr_relation->smgr_rnode.dbNode,
smgr_relation->smgr_rnode.relNode,
numBlocks);
thresholdCount = Min(numBlocks, 1024);
}
loc1 = result->entries[ii].lsn_end;
/*
* if relation was truncated then block_num from change tracking can be beyond numBlocks
*/
if (result->entries[ii].block_num >= numBlocks)
{
ereport(LOG,
(errmsg("could not resynchonize buffer pool relation '%s' block '%d' (maybe due to truncate), "
"lsn change tracking '%s(%u/%u)' "
"number of blocks '%d' ",
relidstr,
result->entries[ii].block_num,
XLogLocationToString(&loc1),
loc1.xlogid,
loc1.xrecoff,
numBlocks),
FileRep_errcontext()));
goto flush_check;
}
/* allow flushing buffers from buffer pool during scan */
FileRepResync_SetReadBufferRequest();
buf = ReadBuffer_Resync(smgr_relation,
result->entries[ii].block_num,
relidstr);
FileRepResync_ResetReadBufferRequest();
Assert(result->entries[ii].block_num < numBlocks);
LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
page = BufferGetPage(buf);
loc = PageGetLSN(page);
if(Debug_filerep_print)
{
elog(LOG,
"incremental resync buffer pool identifier '%s' num blocks '%d' blkno '%d' lsn page '%s(%u/%u)' "
"lsn end change tracking '%s(%u/%u)' ",
relidstr,
numBlocks,
result->entries[ii].block_num,
XLogLocationToString(&loc),
loc.xlogid,
loc.xrecoff,
XLogLocationToString(&loc1),
result->entries[ii].lsn_end.xlogid,
result->entries[ii].lsn_end.xrecoff);
}
else
{
char tmpBuf[FILEREP_MAX_LOG_DESCRIPTION_LEN];
snprintf(tmpBuf, sizeof(tmpBuf),
"incremental resync buffer pool identifier '%s' num blocks '%d' blkno '%d' lsn page '%s(%u/%u)' ",
relidstr,
numBlocks,
result->entries[ii].block_num,
XLogLocationToString(&loc),
loc.xlogid,
loc.xrecoff);
FileRep_InsertConfigLogEntry(tmpBuf);
snprintf(tmpBuf, sizeof(tmpBuf),
"incremental resync buffer pool identifier '%s' lsn end change tracking '%s(%u/%u)' ",
relidstr,
XLogLocationToString(&loc1),
result->entries[ii].lsn_end.xlogid,
result->entries[ii].lsn_end.xrecoff);
FileRep_InsertConfigLogEntry(tmpBuf);
}
if (XLByteLE(result->entries[ii].lsn_end, PageGetLSN(page)))
{
if (! XLByteEQ(PageGetLSN(page), result->entries[ii].lsn_end))
{
ereport(LOG,
(errmsg("Resynchonize buffer pool relation '%s' block '%d' has page lsn less than CT lsn, "
"lsn end change tracking '%s(%u/%u)' lsn page '%s(%u/%u)' "
"number of blocks '%d'",
relidstr,
result->entries[ii].block_num,
XLogLocationToString(&loc),
loc.xlogid,
loc.xrecoff,
XLogLocationToString(&loc1),
loc1.xlogid,
loc1.xrecoff,
numBlocks),
FileRep_errcontext()));
}
/*
* It's safe and better to perform write of the page to mirror,
* for this case, as primary and mirror data pages should always
* be same. So, we might do some extra work but definitely won't
* loose out blocks, or error out and need to perform full recovery.
* Need to cover for this case as there are some known scenarios where
* CT file can have extra records which should have been discarded,
* but as we loose out information of xlog LSN cannot be discarded.
* One such case is when CT_TRANSIENT being compacted to CT_COMPACT
* with specific xlog LSN (to discard extra records) in CT mode gets
* interrupted by resync. Compaction during Resync collects all the
* CT records and doesn't have xlog LSN information to discard any
* extra records from CT_TRANSIENT.
*/
smgrwrite(smgr_relation,
result->entries[ii].block_num,
(char *)BufferGetBlock(buf),
FALSE);
}
#ifdef FAULT_INJECTOR
FaultInjector_InjectFaultIfSet(
FileRepResyncWorker,
DDLNotSpecified,
"", // databaseName
""); // tableName
#endif
UnlockReleaseBuffer(buf);
#ifdef FAULT_INJECTOR
FaultInjector_InjectFaultIfSet(
FileRepResyncWorker,
DDLNotSpecified,
"", // databaseName
""); // tableName
#endif
flush_check:
if (((ii + 1) == result->count) ||
! (result->entries[ii].relFileNode.spcNode == result->entries[ii+1].relFileNode.spcNode &&
result->entries[ii].relFileNode.dbNode == result->entries[ii+1].relFileNode.dbNode &&
result->entries[ii].relFileNode.relNode == result->entries[ii+1].relFileNode.relNode))
{
if (result->ask_for_more == false)
{
smgrimmedsync(smgr_relation);
smgrclose(smgr_relation);
smgr_relation = NULL;
FileRep_GetRelationPath(
entry.fileName,
result->entries[ii].relFileNode,
0 /* segment file number is always 0 for Buffer Pool */);
status = FileRepResync_UpdateEntry(&entry);
if (status != STATUS_OK)
{
break;
}
}
}
if (count > thresholdCount)
{
count = 0;
FileRepSubProcess_ProcessSignals();
if (! (FileRepSubProcess_GetState() == FileRepStateReady &&
dataState == DataStateInResync))
{
mirrorDataLossOccurred = TRUE;
break;
}
}
else
count++;
} // for (ii = 0; ii < result->count; ii++)
} // if ((result = ChangeTracking_GetChanges(request)) != NULL)
FileRepResync_ResetReadBufferRequest();
if (result != NULL && result->ask_for_more == true)
{
Assert(request->count == 1);
request->entries[0].lsn_start = result->next_start_lsn;
}
else
{
break;
}
} // while(1)
ChangeTracking_FreeRequest(request);
ChangeTracking_FreeResult(result);
Insist(NumberOfRelations == 0);
if (mirrorDataLossOccurred)
status = STATUS_ERROR;
return status;
}
static int
FileRepPrimary_ResyncWrite(FileRepResyncHashEntry_s *entry)
{
int status = STATUS_OK;
Page page;
Buffer buf;
BlockNumber numBlocks;
BlockNumber blkno;
SMgrRelation smgr_relation;
char relidstr[OIDCHARS + 1 + OIDCHARS + 1 + OIDCHARS + 1];
XLogRecPtr loc;
int count = 0;
int thresholdCount = 0;
bool mirrorDataLossOccurred = FALSE;
switch (entry->relStorageMgr)
{
case PersistentFileSysRelStorageMgr_BufferPool:
switch (entry->mirrorDataSynchronizationState)
{
case MirroredRelDataSynchronizationState_BufferPoolScanIncremental:
case MirroredRelDataSynchronizationState_FullCopy:
smgr_relation = smgropen(entry->relFileNode);
numBlocks = smgrnblocks(smgr_relation);
snprintf(relidstr, sizeof(relidstr), "%u/%u/%u",
smgr_relation->smgr_rnode.spcNode,
smgr_relation->smgr_rnode.dbNode,
smgr_relation->smgr_rnode.relNode);
if (Debug_filerep_print)
elog(LOG, "resync buffer pool relation '%s' number of blocks '%d' ",
relidstr, numBlocks);
thresholdCount = Min(numBlocks, 1024);
/*
* required in order to report how many blocks were synchronized
* if gp_persistent_relation_node does not return that information
*/
if (entry->mirrorBufpoolResyncChangedPageCount == 0)
{
entry->mirrorBufpoolResyncChangedPageCount = numBlocks - entry->mirrorBufpoolResyncCkptBlockNum;
}
for (blkno = entry->mirrorBufpoolResyncCkptBlockNum; blkno < numBlocks; blkno++)
{
XLogRecPtr endResyncLSN = (isFullResync() ?
FileRepResync_GetEndFullResyncLSN() :
FileRepResync_GetEndIncrResyncLSN());
#ifdef FAULT_INJECTOR
FaultInjector_InjectFaultIfSet(
FileRepResyncWorkerRead,
DDLNotSpecified,
"", //databaseName
""); // tableName
#endif
FileRepResync_SetReadBufferRequest();
buf = ReadBuffer_Resync(smgr_relation, blkno, relidstr);
FileRepResync_ResetReadBufferRequest();
LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
page = BufferGetPage(buf);
loc = PageGetLSN(page);
if (Debug_filerep_print)
{
elog(LOG,
"full resync buffer pool identifier '%s' num blocks '%d' blkno '%d' lsn begin change tracking '%s(%u/%u)' "
"lsn page '%s(%u/%u)' lsn end change tracking '%s(%u/%u)' ",
relidstr,
numBlocks,
blkno,
XLogLocationToString(&entry->mirrorBufpoolResyncCkptLoc),
entry->mirrorBufpoolResyncCkptLoc.xlogid,
entry->mirrorBufpoolResyncCkptLoc.xrecoff,
XLogLocationToString(&loc),
loc.xlogid,
loc.xrecoff,
XLogLocationToString(&endResyncLSN),
endResyncLSN.xlogid,
endResyncLSN.xrecoff);
}
else
{
char tmpBuf[FILEREP_MAX_LOG_DESCRIPTION_LEN];
snprintf(tmpBuf, sizeof(tmpBuf),
"full resync buffer pool identifier '%s' num blocks '%d' blkno '%d' lsn begin change tracking '%s(%u/%u)' ",
relidstr,
numBlocks,
blkno,
XLogLocationToString(&entry->mirrorBufpoolResyncCkptLoc),
entry->mirrorBufpoolResyncCkptLoc.xlogid,
entry->mirrorBufpoolResyncCkptLoc.xrecoff);
FileRep_InsertConfigLogEntry(tmpBuf);
snprintf(tmpBuf, sizeof(tmpBuf),
"full resync buffer pool identifier '%s' lsn page '%s(%u/%u)' lsn end change tracking '%s(%u/%u)' ",
relidstr,
XLogLocationToString(&loc),
loc.xlogid,
loc.xrecoff,
XLogLocationToString(&endResyncLSN),
endResyncLSN.xlogid,
endResyncLSN.xrecoff);
FileRep_InsertConfigLogEntry(tmpBuf);
}
if (XLByteLE(PageGetLSN(page), endResyncLSN) &&
XLByteLE(entry->mirrorBufpoolResyncCkptLoc, PageGetLSN(page)))
{
smgrwrite(smgr_relation,
blkno,
(char *)BufferGetBlock(buf),
FALSE);
}
#ifdef FAULT_INJECTOR
FaultInjector_InjectFaultIfSet(
FileRepResyncWorker,
DDLNotSpecified,
"", // databaseName
""); // tableName
#endif
UnlockReleaseBuffer(buf);
if (count > thresholdCount)
{
count = 0;
FileRepSubProcess_ProcessSignals();
if (! (FileRepSubProcess_GetState() == FileRepStateReady &&
dataState == DataStateInResync))
{
mirrorDataLossOccurred = TRUE;
break;
}
}
else
count++;
}
if (mirrorDataLossOccurred)
break;
if (entry->mirrorDataSynchronizationState != MirroredRelDataSynchronizationState_FullCopy)
{
LockRelationForResyncExtension(&smgr_relation->smgr_rnode, ExclusiveLock);
numBlocks = smgrnblocks(smgr_relation);
smgrtruncate(smgr_relation,
numBlocks,
TRUE /* isTemp, TRUE means to not record in XLOG */,
FALSE /* isLocalBuf */,
&entry->persistentTid,
entry->persistentSerialNum);
UnlockRelationForResyncExtension(&smgr_relation->smgr_rnode, ExclusiveLock);
}
smgrimmedsync(smgr_relation);
smgrclose(smgr_relation);
smgr_relation = NULL;
break;
case MirroredRelDataSynchronizationState_None:
case MirroredRelDataSynchronizationState_DataSynchronized:
break;
default:
ereport(LOG,
(errmsg("could not resynchronize relation '%u/%u/%u' "
"mirror synchronization state:'%s(%d)' ",
entry->relFileNode.relNode,
entry->relFileNode.spcNode,
entry->relFileNode.dbNode,
MirroredRelDataSynchronizationState_Name(entry->mirrorDataSynchronizationState),
entry->mirrorDataSynchronizationState)));
break;
}
break;
case PersistentFileSysRelStorageMgr_AppendOnly:
{
MirroredAppendOnlyOpen mirroredOpen;
int primaryError;
bool mirrorDataLossOccurred;
char *buffer = NULL;
int64 endOffset = entry->mirrorAppendOnlyNewEof;
int64 startOffset = entry->mirrorAppendOnlyLossEof;
int32 bufferLen = 0;
int retval = 0;
switch (entry->mirrorDataSynchronizationState)
{
case MirroredRelDataSynchronizationState_AppendOnlyCatchup:
case MirroredRelDataSynchronizationState_FullCopy:
/*
* required in order to report how many blocks were synchronized
* if gp_persistent_relation_node does not return that information
*/
if (entry->mirrorBufpoolResyncChangedPageCount == 0)
{
entry->mirrorBufpoolResyncChangedPageCount = (endOffset - startOffset) / BLCKSZ;
}
/*
* The MirroredAppendOnly_OpenResynchonize routine knows we are a resynch worker and
* will open BOTH, but write only the MIRROR!!!
*/
MirroredAppendOnly_OpenResynchonize(
&mirroredOpen,
&entry->relFileNode,
entry->segmentFileNum,
startOffset,
&primaryError,
&mirrorDataLossOccurred);
if (primaryError != 0)
{
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not open file %u/%u/%u.%u : %s",
entry->relFileNode.dbNode,
entry->relFileNode.spcNode,
entry->relFileNode.relNode,
entry->segmentFileNum,
strerror(primaryError))));
break;
}
if (mirrorDataLossOccurred)
break;
/* AO and CO Data Store writes 64k size by default */
bufferLen = (Size) Min(2*BLCKSZ, endOffset - startOffset);
buffer = (char*) palloc(bufferLen);
if (buffer == NULL)
ereport(ERROR,
(errcode(ERRCODE_OUT_OF_MEMORY),
(errmsg("not enough memory for resynchronization"))));
MemSet(buffer, 0, bufferLen);
while (startOffset < endOffset)
{
retval = MirroredAppendOnly_Read(
&mirroredOpen,
buffer,
bufferLen);
if (retval != bufferLen)
{
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not read from position:" INT64_FORMAT " in file %u/%u/%u.%u : %m",
startOffset,
entry->relFileNode.dbNode,
entry->relFileNode.spcNode,
entry->relFileNode.relNode,
entry->segmentFileNum)));
break;
}
MirroredAppendOnly_Append(
&mirroredOpen,
buffer,
bufferLen,
&primaryError,
&mirrorDataLossOccurred);
if (mirrorDataLossOccurred)
break;
Assert(primaryError == 0); // No primary writes as resync worker.
startOffset += bufferLen;
/* AO and CO Data Store writes 64k size by default */
bufferLen = (Size) Min(2*BLCKSZ, endOffset - startOffset);
}
if (buffer)
{
pfree(buffer);
buffer = NULL;
}
if (mirrorDataLossOccurred)
break;
/* Flush written data on Mirror */
MirroredAppendOnly_Flush(
&mirroredOpen,
&primaryError,
&mirrorDataLossOccurred);
if (mirrorDataLossOccurred)
break;
Assert(primaryError == 0); // Not flushed on primary as resync worker.
/* Close Primary and Mirror */
MirroredAppendOnly_Close(
&mirroredOpen,
&mirrorDataLossOccurred);
break;
case MirroredRelDataSynchronizationState_None:
case MirroredRelDataSynchronizationState_DataSynchronized:
break;
default:
ereport(LOG,
(errmsg("could not resynchronize relation '%u/%u/%u' "
"mirror synchronization state:'%s(%d)' ",
entry->relFileNode.relNode,
entry->relFileNode.spcNode,
entry->relFileNode.dbNode,
MirroredRelDataSynchronizationState_Name(entry->mirrorDataSynchronizationState),
entry->mirrorDataSynchronizationState)));
break;
}
break;
} //case
default:
Assert(0);
break;
} //switch
if (mirrorDataLossOccurred)
status = STATUS_ERROR;
return status;
}
/*
* FinishPreparedTransaction: execute COMMIT PREPARED or ROLLBACK PREPARED
*/
void
FinishPreparedTransaction(const char *gid, bool isCommit)
{
GlobalTransaction gxact;
TransactionId xid;
char *buf;
char *bufptr;
TwoPhaseFileHeader *hdr;
TransactionId latestXid;
TransactionId *children;
RelFileNode *commitrels;
RelFileNode *abortrels;
RelFileNode *delrels;
int ndelrels;
int i;
/*
* Validate the GID, and lock the GXACT to ensure that two backends do not
* try to commit the same GID at once.
*/
gxact = LockGXact(gid, GetUserId());
xid = gxact->proc.xid;
/*
* Read and validate the state file
*/
buf = ReadTwoPhaseFile(xid);
if (buf == NULL)
ereport(ERROR,
(errcode(ERRCODE_DATA_CORRUPTED),
errmsg("two-phase state file for transaction %u is corrupt",
xid)));
/*
* Disassemble the header area
*/
hdr = (TwoPhaseFileHeader *) buf;
Assert(TransactionIdEquals(hdr->xid, xid));
bufptr = buf + MAXALIGN(sizeof(TwoPhaseFileHeader));
children = (TransactionId *) bufptr;
bufptr += MAXALIGN(hdr->nsubxacts * sizeof(TransactionId));
commitrels = (RelFileNode *) bufptr;
bufptr += MAXALIGN(hdr->ncommitrels * sizeof(RelFileNode));
abortrels = (RelFileNode *) bufptr;
bufptr += MAXALIGN(hdr->nabortrels * sizeof(RelFileNode));
/* compute latestXid among all children */
latestXid = TransactionIdLatest(xid, hdr->nsubxacts, children);
/*
* The order of operations here is critical: make the XLOG entry for
* commit or abort, then mark the transaction committed or aborted in
* pg_clog, then remove its PGPROC from the global ProcArray (which means
* TransactionIdIsInProgress will stop saying the prepared xact is in
* progress), then run the post-commit or post-abort callbacks. The
* callbacks will release the locks the transaction held.
*/
if (isCommit)
RecordTransactionCommitPrepared(xid,
hdr->nsubxacts, children,
hdr->ncommitrels, commitrels);
else
RecordTransactionAbortPrepared(xid,
hdr->nsubxacts, children,
hdr->nabortrels, abortrels);
ProcArrayRemove(&gxact->proc, latestXid);
/*
* In case we fail while running the callbacks, mark the gxact invalid so
* no one else will try to commit/rollback, and so it can be recycled
* properly later. It is still locked by our XID so it won't go away yet.
*
* (We assume it's safe to do this without taking TwoPhaseStateLock.)
*/
gxact->valid = false;
/*
* We have to remove any files that were supposed to be dropped. For
* consistency with the regular xact.c code paths, must do this before
* releasing locks, so do it before running the callbacks.
*
* NB: this code knows that we couldn't be dropping any temp rels ...
*/
if (isCommit)
{
delrels = commitrels;
ndelrels = hdr->ncommitrels;
}
else
{
delrels = abortrels;
ndelrels = hdr->nabortrels;
}
for (i = 0; i < ndelrels; i++)
{
SMgrRelation srel = smgropen(delrels[i]);
ForkNumber fork;
for (fork = 0; fork <= MAX_FORKNUM; fork++)
{
if (smgrexists(srel, fork))
smgrdounlink(srel, fork, false, false);
}
smgrclose(srel);
}
/* And now do the callbacks */
if (isCommit)
ProcessRecords(bufptr, xid, twophase_postcommit_callbacks);
else
ProcessRecords(bufptr, xid, twophase_postabort_callbacks);
/* Count the prepared xact as committed or aborted */
AtEOXact_PgStat(isCommit);
/*
* And now we can clean up our mess.
*/
RemoveTwoPhaseFile(xid, true);
RemoveGXact(gxact);
pfree(buf);
}
/*
* LocalBufferAlloc -
* Find or create a local buffer for the given page of the given relation.
*
* API is similar to bufmgr.c's BufferAlloc, except that we do not need
* to do any locking since this is all local. Also, IO_IN_PROGRESS
* does not get set. Lastly, we support only default access strategy
* (hence, usage_count is always advanced).
*/
BufferDesc *
LocalBufferAlloc(SMgrRelation smgr, ForkNumber forkNum, BlockNumber blockNum,
bool *foundPtr)
{
BufferTag newTag; /* identity of requested block */
LocalBufferLookupEnt *hresult;
BufferDesc *bufHdr;
int b;
int trycounter;
bool found;
INIT_BUFFERTAG(newTag, smgr->smgr_rnode.node, forkNum, blockNum);
/* Initialize local buffers if first request in this session */
if (LocalBufHash == NULL)
InitLocalBuffers();
/* See if the desired buffer already exists */
hresult = (LocalBufferLookupEnt *)
hash_search(LocalBufHash, (void *) &newTag, HASH_FIND, NULL);
if (hresult)
{
b = hresult->id;
bufHdr = &LocalBufferDescriptors[b];
Assert(BUFFERTAGS_EQUAL(bufHdr->tag, newTag));
#ifdef LBDEBUG
fprintf(stderr, "LB ALLOC (%u,%d,%d) %d\n",
smgr->smgr_rnode.node.relNode, forkNum, blockNum, -b - 1);
#endif
/* this part is equivalent to PinBuffer for a shared buffer */
if (LocalRefCount[b] == 0)
{
if (bufHdr->usage_count < BM_MAX_USAGE_COUNT)
bufHdr->usage_count++;
}
LocalRefCount[b]++;
ResourceOwnerRememberBuffer(CurrentResourceOwner,
BufferDescriptorGetBuffer(bufHdr));
if (bufHdr->flags & BM_VALID)
*foundPtr = TRUE;
else
{
/* Previous read attempt must have failed; try again */
*foundPtr = FALSE;
}
return bufHdr;
}
#ifdef LBDEBUG
fprintf(stderr, "LB ALLOC (%u,%d,%d) %d\n",
smgr->smgr_rnode.node.relNode, forkNum, blockNum,
-nextFreeLocalBuf - 1);
#endif
/*
* Need to get a new buffer. We use a clock sweep algorithm (essentially
* the same as what freelist.c does now...)
*/
trycounter = NLocBuffer;
for (;;)
{
b = nextFreeLocalBuf;
if (++nextFreeLocalBuf >= NLocBuffer)
nextFreeLocalBuf = 0;
bufHdr = &LocalBufferDescriptors[b];
if (LocalRefCount[b] == 0)
{
if (bufHdr->usage_count > 0)
{
bufHdr->usage_count--;
trycounter = NLocBuffer;
}
else
{
/* Found a usable buffer */
LocalRefCount[b]++;
ResourceOwnerRememberBuffer(CurrentResourceOwner,
BufferDescriptorGetBuffer(bufHdr));
break;
}
}
else if (--trycounter == 0)
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_RESOURCES),
errmsg("no empty local buffer available")));
}
/*
* this buffer is not referenced but it might still be dirty. if that's
* the case, write it out before reusing it!
*/
if (bufHdr->flags & BM_DIRTY)
{
SMgrRelation oreln;
/* Find smgr relation for buffer */
oreln = smgropen(bufHdr->tag.rnode, MyBackendId);
/* And write... */
smgrwrite(oreln,
bufHdr->tag.forkNum,
bufHdr->tag.blockNum,
(char *) LocalBufHdrGetBlock(bufHdr),
false);
/* Mark not-dirty now in case we error out below */
bufHdr->flags &= ~BM_DIRTY;
pgBufferUsage.local_blks_written++;
}
/*
* lazy memory allocation: allocate space on first use of a buffer.
*/
if (LocalBufHdrGetBlock(bufHdr) == NULL)
{
/* Set pointer for use by BufferGetBlock() macro */
LocalBufHdrGetBlock(bufHdr) = GetLocalBufferStorage();
}
/*
* Update the hash table: remove old entry, if any, and make new one.
*/
if (bufHdr->flags & BM_TAG_VALID)
{
hresult = (LocalBufferLookupEnt *)
hash_search(LocalBufHash, (void *) &bufHdr->tag,
HASH_REMOVE, NULL);
if (!hresult) /* shouldn't happen */
elog(ERROR, "local buffer hash table corrupted");
/* mark buffer invalid just in case hash insert fails */
CLEAR_BUFFERTAG(bufHdr->tag);
bufHdr->flags &= ~(BM_VALID | BM_TAG_VALID);
}
hresult = (LocalBufferLookupEnt *)
hash_search(LocalBufHash, (void *) &newTag, HASH_ENTER, &found);
if (found) /* shouldn't happen */
elog(ERROR, "local buffer hash table corrupted");
hresult->id = b;
/*
* it's all ours now.
*/
bufHdr->tag = newTag;
bufHdr->flags &= ~(BM_VALID | BM_DIRTY | BM_JUST_DIRTIED | BM_IO_ERROR);
bufHdr->flags |= BM_TAG_VALID;
bufHdr->usage_count = 1;
*foundPtr = FALSE;
return bufHdr;
}
/*
* XLogReadBufferExtended
* Read a page during XLOG replay
*
* This is functionally comparable to ReadBufferExtended. There's some
* differences in the behavior wrt. the "mode" argument:
*
* In RBM_NORMAL mode, if the page doesn't exist, or contains all-zeroes, we
* return InvalidBuffer. In this case the caller should silently skip the
* update on this page. (In this situation, we expect that the page was later
* dropped or truncated. If we don't see evidence of that later in the WAL
* sequence, we'll complain at the end of WAL replay.)
*
* In RBM_ZERO_* modes, if the page doesn't exist, the relation is extended
* with all-zeroes pages up to the given block number.
*
* In RBM_NORMAL_NO_LOG mode, we return InvalidBuffer if the page doesn't
* exist, and we don't check for all-zeroes. Thus, no log entry is made
* to imply that the page should be dropped or truncated later.
*
* NB: A redo function should normally not call this directly. To get a page
* to modify, use XLogReplayBuffer instead. It is important that all pages
* modified by a WAL record are registered in the WAL records, or they will be
* invisible to tools that that need to know which pages are modified.
*/
Buffer
XLogReadBufferExtended(RelFileNode rnode, ForkNumber forknum,
BlockNumber blkno, ReadBufferMode mode)
{
BlockNumber lastblock;
Buffer buffer;
SMgrRelation smgr;
Assert(blkno != P_NEW);
/* Open the relation at smgr level */
smgr = smgropen(rnode, InvalidBackendId);
/*
* Create the target file if it doesn't already exist. This lets us cope
* if the replay sequence contains writes to a relation that is later
* deleted. (The original coding of this routine would instead suppress
* the writes, but that seems like it risks losing valuable data if the
* filesystem loses an inode during a crash. Better to write the data
* until we are actually told to delete the file.)
*/
smgrcreate(smgr, forknum, true);
lastblock = smgrnblocks(smgr, forknum);
if (blkno < lastblock)
{
/* page exists in file */
buffer = ReadBufferWithoutRelcache(rnode, forknum, blkno,
mode, NULL);
}
else
{
/* hm, page doesn't exist in file */
if (mode == RBM_NORMAL)
{
log_invalid_page(rnode, forknum, blkno, false);
return InvalidBuffer;
}
if (mode == RBM_NORMAL_NO_LOG)
return InvalidBuffer;
/* OK to extend the file */
/* we do this in recovery only - no rel-extension lock needed */
Assert(InRecovery);
buffer = InvalidBuffer;
do
{
if (buffer != InvalidBuffer)
{
if (mode == RBM_ZERO_AND_LOCK || mode == RBM_ZERO_AND_CLEANUP_LOCK)
LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
ReleaseBuffer(buffer);
}
buffer = ReadBufferWithoutRelcache(rnode, forknum,
P_NEW, mode, NULL);
}
while (BufferGetBlockNumber(buffer) < blkno);
/* Handle the corner case that P_NEW returns non-consecutive pages */
if (BufferGetBlockNumber(buffer) != blkno)
{
if (mode == RBM_ZERO_AND_LOCK || mode == RBM_ZERO_AND_CLEANUP_LOCK)
LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
ReleaseBuffer(buffer);
buffer = ReadBufferWithoutRelcache(rnode, forknum, blkno,
mode, NULL);
}
}
if (mode == RBM_NORMAL)
{
/* check that page has been initialized */
Page page = (Page) BufferGetPage(buffer);
/*
* We assume that PageIsNew is safe without a lock. During recovery,
* there should be no other backends that could modify the buffer at
* the same time.
*/
if (PageIsNew(page))
{
ReleaseBuffer(buffer);
log_invalid_page(rnode, forknum, blkno, true);
return InvalidBuffer;
}
}
return buffer;
}
/*
* mdsync() -- Sync previous writes to stable storage.
*/
void
mdsync(void)
{
static bool mdsync_in_progress = false;
HASH_SEQ_STATUS hstat;
PendingOperationEntry *entry;
int absorb_counter;
/*
* This is only called during checkpoints, and checkpoints should only
* occur in processes that have created a pendingOpsTable.
*/
if (!pendingOpsTable)
elog(ERROR, "cannot sync without a pendingOpsTable");
/*
* If we are in the bgwriter, the sync had better include all fsync
* requests that were queued by backends up to this point. The tightest
* race condition that could occur is that a buffer that must be written
* and fsync'd for the checkpoint could have been dumped by a backend just
* before it was visited by BufferSync(). We know the backend will have
* queued an fsync request before clearing the buffer's dirtybit, so we
* are safe as long as we do an Absorb after completing BufferSync().
*/
AbsorbFsyncRequests();
/*
* To avoid excess fsync'ing (in the worst case, maybe a never-terminating
* checkpoint), we want to ignore fsync requests that are entered into the
* hashtable after this point --- they should be processed next time,
* instead. We use mdsync_cycle_ctr to tell old entries apart from new
* ones: new ones will have cycle_ctr equal to the incremented value of
* mdsync_cycle_ctr.
*
* In normal circumstances, all entries present in the table at this point
* will have cycle_ctr exactly equal to the current (about to be old)
* value of mdsync_cycle_ctr. However, if we fail partway through the
* fsync'ing loop, then older values of cycle_ctr might remain when we
* come back here to try again. Repeated checkpoint failures would
* eventually wrap the counter around to the point where an old entry
* might appear new, causing us to skip it, possibly allowing a checkpoint
* to succeed that should not have. To forestall wraparound, any time the
* previous mdsync() failed to complete, run through the table and
* forcibly set cycle_ctr = mdsync_cycle_ctr.
*
* Think not to merge this loop with the main loop, as the problem is
* exactly that that loop may fail before having visited all the entries.
* From a performance point of view it doesn't matter anyway, as this path
* will never be taken in a system that's functioning normally.
*/
if (mdsync_in_progress)
{
/* prior try failed, so update any stale cycle_ctr values */
hash_seq_init(&hstat, pendingOpsTable);
while ((entry = (PendingOperationEntry *) hash_seq_search(&hstat)) != NULL)
{
entry->cycle_ctr = mdsync_cycle_ctr;
}
}
/* Advance counter so that new hashtable entries are distinguishable */
mdsync_cycle_ctr++;
/* Set flag to detect failure if we don't reach the end of the loop */
mdsync_in_progress = true;
/* Now scan the hashtable for fsync requests to process */
absorb_counter = FSYNCS_PER_ABSORB;
hash_seq_init(&hstat, pendingOpsTable);
while ((entry = (PendingOperationEntry *) hash_seq_search(&hstat)) != NULL)
{
/*
* If the entry is new then don't process it this time. Note that
* "continue" bypasses the hash-remove call at the bottom of the loop.
*/
if (entry->cycle_ctr == mdsync_cycle_ctr)
continue;
/* Else assert we haven't missed it */
Assert((CycleCtr) (entry->cycle_ctr + 1) == mdsync_cycle_ctr);
/*
* If fsync is off then we don't have to bother opening the file at
* all. (We delay checking until this point so that changing fsync on
* the fly behaves sensibly.) Also, if the entry is marked canceled,
* fall through to delete it.
*/
if (enableFsync && !entry->canceled)
{
int failures;
/*
* If in bgwriter, we want to absorb pending requests every so
* often to prevent overflow of the fsync request queue. It is
* unspecified whether newly-added entries will be visited by
* hash_seq_search, but we don't care since we don't need to
* process them anyway.
*/
if (--absorb_counter <= 0)
{
AbsorbFsyncRequests();
absorb_counter = FSYNCS_PER_ABSORB;
}
/*
* The fsync table could contain requests to fsync segments that
* have been deleted (unlinked) by the time we get to them. Rather
* than just hoping an ENOENT (or EACCES on Windows) error can be
* ignored, what we do on error is absorb pending requests and
* then retry. Since mdunlink() queues a "revoke" message before
* actually unlinking, the fsync request is guaranteed to be
* marked canceled after the absorb if it really was this case.
* DROP DATABASE likewise has to tell us to forget fsync requests
* before it starts deletions.
*/
for (failures = 0;; failures++) /* loop exits at "break" */
{
SMgrRelation reln;
MdfdVec *seg;
char *path;
/*
* Find or create an smgr hash entry for this relation. This
* may seem a bit unclean -- md calling smgr? But it's really
* the best solution. It ensures that the open file reference
* isn't permanently leaked if we get an error here. (You may
* say "but an unreferenced SMgrRelation is still a leak!" Not
* really, because the only case in which a checkpoint is done
* by a process that isn't about to shut down is in the
* bgwriter, and it will periodically do smgrcloseall(). This
* fact justifies our not closing the reln in the success path
* either, which is a good thing since in non-bgwriter cases
* we couldn't safely do that.) Furthermore, in many cases
* the relation will have been dirtied through this same smgr
* relation, and so we can save a file open/close cycle.
*/
reln = smgropen(entry->tag.rnode);
/*
* It is possible that the relation has been dropped or
* truncated since the fsync request was entered. Therefore,
* allow ENOENT, but only if we didn't fail already on this
* file. This applies both during _mdfd_getseg() and during
* FileSync, since fd.c might have closed the file behind our
* back.
*/
seg = _mdfd_getseg(reln, entry->tag.forknum,
entry->tag.segno * ((BlockNumber) RELSEG_SIZE),
false, EXTENSION_RETURN_NULL);
if (seg != NULL &&
FileSync(seg->mdfd_vfd) >= 0)
break; /* success; break out of retry loop */
/*
* XXX is there any point in allowing more than one retry?
* Don't see one at the moment, but easy to change the test
* here if so.
*/
path = _mdfd_segpath(reln, entry->tag.forknum,
entry->tag.segno);
if (!FILE_POSSIBLY_DELETED(errno) ||
failures > 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not fsync file \"%s\": %m", path)));
else
ereport(DEBUG1,
(errcode_for_file_access(),
errmsg("could not fsync file \"%s\" but retrying: %m",
path)));
pfree(path);
/*
* Absorb incoming requests and check to see if canceled.
*/
AbsorbFsyncRequests();
absorb_counter = FSYNCS_PER_ABSORB; /* might as well... */
if (entry->canceled)
break;
} /* end retry loop */
}
/*
* If we get here, either we fsync'd successfully, or we don't have to
* because enableFsync is off, or the entry is (now) marked canceled.
* Okay to delete it.
*/
if (hash_search(pendingOpsTable, &entry->tag,
HASH_REMOVE, NULL) == NULL)
elog(ERROR, "pendingOpsTable corrupted");
} /* end loop over hashtable entries */
/* Flag successful completion of mdsync */
mdsync_in_progress = false;
}
void
smgr_redo(XLogRecPtr lsn, XLogRecord *record)
{
uint8 info = record->xl_info & ~XLR_INFO_MASK;
if (info == XLOG_SMGR_CREATE)
{
xl_smgr_create *xlrec = (xl_smgr_create *) XLogRecGetData(record);
SMgrRelation reln;
reln = smgropen(xlrec->rnode);
smgrcreate(reln, false, true);
}
else if (info == XLOG_SMGR_TRUNCATE)
{
xl_smgr_truncate *xlrec = (xl_smgr_truncate *) XLogRecGetData(record);
SMgrRelation reln;
BlockNumber newblks;
reln = smgropen(xlrec->rnode);
/*
* Forcibly create relation if it doesn't exist (which suggests that
* it was dropped somewhere later in the WAL sequence). As in
* XLogOpenRelation, we prefer to recreate the rel and replay the
* log as best we can until the drop is seen.
*/
smgrcreate(reln, false, true);
/* Can't use smgrtruncate because it would try to xlog */
/*
* First, force bufmgr to drop any buffers it has for the to-be-
* truncated blocks. We must do this, else subsequent XLogReadBuffer
* operations will not re-extend the file properly.
*/
DropRelFileNodeBuffers(xlrec->rnode, false, xlrec->blkno);
/*
* Tell the free space map to forget anything it may have stored for
* the about-to-be-deleted blocks. We want to be sure it won't return
* bogus block numbers later on.
*/
FreeSpaceMapTruncateRel(&reln->smgr_rnode, xlrec->blkno);
/* Do the truncation */
newblks = (*(smgrsw[reln->smgr_which].smgr_truncate)) (reln,
xlrec->blkno,
false);
if (newblks == InvalidBlockNumber)
ereport(WARNING,
(errcode_for_file_access(),
errmsg("could not truncate relation %u/%u/%u to %u blocks: %m",
reln->smgr_rnode.spcNode,
reln->smgr_rnode.dbNode,
reln->smgr_rnode.relNode,
xlrec->blkno)));
/* Also tell xlogutils.c about it */
XLogTruncateRelation(xlrec->rnode, xlrec->blkno);
}
else
elog(PANIC, "smgr_redo: unknown op code %u", info);
}
void
smgr_redo(XLogRecPtr lsn, XLogRecord *record)
{
uint8 info = record->xl_info & ~XLR_INFO_MASK;
/* Backup blocks are not used in smgr records */
Assert(!(record->xl_info & XLR_BKP_BLOCK_MASK));
if (info == XLOG_SMGR_CREATE)
{
xl_smgr_create *xlrec = (xl_smgr_create *) XLogRecGetData(record);
SMgrRelation reln;
reln = smgropen(xlrec->rnode, InvalidBackendId);
smgrcreate(reln, xlrec->forkNum, true);
}
else if (info == XLOG_SMGR_TRUNCATE)
{
xl_smgr_truncate *xlrec = (xl_smgr_truncate *) XLogRecGetData(record);
SMgrRelation reln;
Relation rel;
reln = smgropen(xlrec->rnode, InvalidBackendId);
/*
* Forcibly create relation if it doesn't exist (which suggests that
* it was dropped somewhere later in the WAL sequence). As in
* XLogReadBuffer, we prefer to recreate the rel and replay the log as
* best we can until the drop is seen.
*/
smgrcreate(reln, MAIN_FORKNUM, true);
/*
* Before we perform the truncation, update minimum recovery point
* to cover this WAL record. Once the relation is truncated, there's
* no going back. The buffer manager enforces the WAL-first rule
* for normal updates to relation files, so that the minimum recovery
* point is always updated before the corresponding change in the
* data file is flushed to disk. We have to do the same manually
* here.
*
* Doing this before the truncation means that if the truncation fails
* for some reason, you cannot start up the system even after restart,
* until you fix the underlying situation so that the truncation will
* succeed. Alternatively, we could update the minimum recovery point
* after truncation, but that would leave a small window where the
* WAL-first rule could be violated.
*/
XLogFlush(lsn);
smgrtruncate(reln, MAIN_FORKNUM, xlrec->blkno);
/* Also tell xlogutils.c about it */
XLogTruncateRelation(xlrec->rnode, MAIN_FORKNUM, xlrec->blkno);
/* Truncate FSM and VM too */
rel = CreateFakeRelcacheEntry(xlrec->rnode);
if (smgrexists(reln, FSM_FORKNUM))
FreeSpaceMapTruncateRel(rel, xlrec->blkno);
if (smgrexists(reln, VISIBILITYMAP_FORKNUM))
visibilitymap_truncate(rel, xlrec->blkno);
FreeFakeRelcacheEntry(rel);
}
else
elog(PANIC, "smgr_redo: unknown op code %u", info);
}
/*
* mdsync() -- Sync previous writes to stable storage.
*
* This is only called during checkpoints, and checkpoints should only
* occur in processes that have created a pendingOpsTable.
*/
bool
mdsync(void)
{
HASH_SEQ_STATUS hstat;
PendingOperationEntry *entry;
if (!pendingOpsTable)
return false;
/*
* If we are in the bgwriter, the sync had better include all fsync
* requests that were queued by backends before the checkpoint REDO point
* was determined. We go that a little better by accepting all requests
* queued up to the point where we start fsync'ing.
*/
AbsorbFsyncRequests();
hash_seq_init(&hstat, pendingOpsTable);
while ((entry = (PendingOperationEntry *) hash_seq_search(&hstat)) != NULL)
{
/*
* If fsync is off then we don't have to bother opening the file at
* all. (We delay checking until this point so that changing fsync on
* the fly behaves sensibly.)
*/
if (enableFsync)
{
SMgrRelation reln;
MdfdVec *seg;
/*
* Find or create an smgr hash entry for this relation. This may
* seem a bit unclean -- md calling smgr? But it's really the
* best solution. It ensures that the open file reference isn't
* permanently leaked if we get an error here. (You may say "but
* an unreferenced SMgrRelation is still a leak!" Not really,
* because the only case in which a checkpoint is done by a
* process that isn't about to shut down is in the bgwriter, and
* it will periodically do smgrcloseall(). This fact justifies
* our not closing the reln in the success path either, which is a
* good thing since in non-bgwriter cases we couldn't safely do
* that.) Furthermore, in many cases the relation will have been
* dirtied through this same smgr relation, and so we can save a
* file open/close cycle.
*/
reln = smgropen(entry->rnode);
/*
* It is possible that the relation has been dropped or truncated
* since the fsync request was entered. Therefore, we have to
* allow file-not-found errors. This applies both during
* _mdfd_getseg() and during FileSync, since fd.c might have
* closed the file behind our back.
*/
seg = _mdfd_getseg(reln,
entry->segno * ((BlockNumber) RELSEG_SIZE),
true);
if (seg)
{
if (FileSync(seg->mdfd_vfd) < 0 &&
errno != ENOENT)
{
ereport(LOG,
(errcode_for_file_access(),
errmsg("could not fsync segment %u of relation %u/%u/%u: %m",
entry->segno,
entry->rnode.spcNode,
entry->rnode.dbNode,
entry->rnode.relNode)));
return false;
}
}
}
/* Okay, delete this entry */
if (hash_search(pendingOpsTable, entry,
HASH_REMOVE, NULL) == NULL)
elog(ERROR, "pendingOpsTable corrupted");
}
return true;
}
static int64
PersistentBuild_TruncateAllGpRelationNode(void)
{
Relation pg_database;
HeapScanDesc scan;
HeapTuple tuple;
int64 count;
pg_database = heap_open(
DatabaseRelationId,
AccessShareLock);
/*
* Truncate gp_relation_node and its index in each database.
*/
scan = heap_beginscan(pg_database, SnapshotNow, 0, NULL);
count = 0;
while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
{
Form_pg_database form_pg_database =
(Form_pg_database)GETSTRUCT(tuple);
Oid dbOid;
Oid dattablespace;
RelFileNode relFileNode;
SMgrRelation smgrRelation;
Page btree_metapage;
dbOid = HeapTupleGetOid(tuple);
dattablespace = form_pg_database->dattablespace;
if (dbOid == HcatalogDbOid)
continue;
if (Debug_persistent_print)
elog(Persistent_DebugPrintLevel(),
"PersistentBuild_TruncateAllGpRelationNode: dbOid %u, '%s'",
dbOid,
form_pg_database->datname.data);
if (Debug_persistent_print)
elog(Persistent_DebugPrintLevel(),
"Truncating gp_relation_node %u/%u/%u in database oid %u ('%s')",
relFileNode.spcNode,
relFileNode.dbNode,
relFileNode.relNode,
dbOid,
form_pg_database->datname.data);
relFileNode.spcNode = dattablespace;
relFileNode.dbNode = dbOid;
relFileNode.relNode = GpRelfileNodeRelationId;
/*
* Truncate WITHOUT generating an XLOG record (i.e. pretend it is a temp relation).
*/
PersistentBuild_NonTransactionTruncate(&relFileNode);
count++;
/*
* And, the index. Unfortunately, the relfilenode OID can change due to a
* REINDEX {TABLE|INDEX} command.
*/
PersistentBuild_FindGpRelationNodeIndex(
dbOid,
dattablespace,
&relFileNode);
if (Debug_persistent_print)
elog(Persistent_DebugPrintLevel(),
"Truncating gp_relation_node_index %u/%u/%u in database oid %u ('%s'). relfilenode different %s, tablespace different %s",
relFileNode.spcNode,
relFileNode.dbNode,
relFileNode.relNode,
dbOid,
form_pg_database->datname.data,
((relFileNode.relNode != GpRelfileNodeOidIndexId) ? "true" : "false"),
((relFileNode.spcNode != dattablespace) ? "true" : "false"));
PersistentBuild_NonTransactionTruncate(&relFileNode);
// The BTree needs an empty meta-data block.
smgrRelation = smgropen(relFileNode);
btree_metapage = (Page)palloc(BLCKSZ);
_bt_initmetapage(btree_metapage, P_NONE, 0);
smgrwrite(
smgrRelation,
/* blockNum */ 0,
(char*)btree_metapage,
/* isTemp */ false);
smgrimmedsync(smgrRelation);
pfree(btree_metapage);
smgrclose(smgrRelation);
count++;
}
heap_endscan(scan);
heap_close(pg_database, AccessShareLock);
return count;
}
/*
* smgrDoPendingDeletes() -- Take care of relation deletes at end of xact.
*
* This also runs when aborting a subxact; we want to clean up a failed
* subxact immediately.
*
* Note: It's possible that we're being asked to remove a relation that has
* no physical storage in any fork. In particular, it's possible that we're
* cleaning up an old temporary relation for which RemovePgTempFiles has
* already recovered the physical storage.
*/
void
smgrDoPendingDeletes(bool isCommit)
{
int nestLevel = GetCurrentTransactionNestLevel();
PendingRelDelete *pending;
PendingRelDelete *prev;
PendingRelDelete *next;
int nrels = 0,
i = 0,
maxrels = 0;
SMgrRelation *srels = NULL;
prev = NULL;
for (pending = pendingDeletes; pending != NULL; pending = next)
{
next = pending->next;
if (pending->nestLevel < nestLevel)
{
/* outer-level entries should not be processed yet */
prev = pending;
}
else
{
/* unlink list entry first, so we don't retry on failure */
if (prev)
prev->next = next;
else
pendingDeletes = next;
/* do deletion if called for */
if (pending->atCommit == isCommit)
{
SMgrRelation srel;
srel = smgropen(pending->relnode, pending->backend);
/* allocate the initial array, or extend it, if needed */
if (maxrels == 0)
{
maxrels = 8;
srels = palloc(sizeof(SMgrRelation) * maxrels);
}
else if (maxrels <= nrels)
{
maxrels *= 2;
srels = repalloc(srels, sizeof(SMgrRelation) * maxrels);
}
srels[nrels++] = srel;
}
/* must explicitly free the list entry */
pfree(pending);
/* prev does not change */
}
}
if (nrels > 0)
{
smgrdounlinkall(srels, nrels, false);
for (i = 0; i < nrels; i++)
smgrclose(srels[i]);
pfree(srels);
}
}
