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Diffstat (limited to 'src/backend/access/transam/xlog.c')
-rw-r--r--src/backend/access/transam/xlog.c116
1 files changed, 61 insertions, 55 deletions
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index e65c109f665..e8f9ea20de7 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2004, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.166 2004/08/29 05:06:40 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.167 2004/08/29 16:34:47 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -409,6 +409,10 @@ static uint32 readOff = 0;
/* Buffer for currently read page (BLCKSZ bytes) */
static char *readBuf = NULL;
+/* Buffer for current ReadRecord result (expandable) */
+static char *readRecordBuf = NULL;
+static uint32 readRecordBufSize = 0;
+
/* State information for XLOG reading */
static XLogRecPtr ReadRecPtr;
static XLogRecPtr EndRecPtr;
@@ -440,11 +444,9 @@ static bool RestoreArchivedFile(char *path, const char *xlogfname,
const char *recovername, off_t expectedSize);
static void PreallocXlogFiles(XLogRecPtr endptr);
static void MoveOfflineLogs(uint32 log, uint32 seg, XLogRecPtr endptr);
-static XLogRecord *ReadRecord(XLogRecPtr *RecPtr, int emode, char *buffer);
+static XLogRecord *ReadRecord(XLogRecPtr *RecPtr, int emode);
static bool ValidXLOGHeader(XLogPageHeader hdr, int emode);
-static XLogRecord *ReadCheckpointRecord(XLogRecPtr RecPtr,
- int whichChkpt,
- char *buffer);
+static XLogRecord *ReadCheckpointRecord(XLogRecPtr RecPtr, int whichChkpt);
static List *readTimeLineHistory(TimeLineID targetTLI);
static bool existsTimeLineHistory(TimeLineID probeTLI);
static TimeLineID findNewestTimeLine(TimeLineID startTLI);
@@ -627,7 +629,7 @@ begin:;
* may not be true forever. If you need to remove the len == 0 check,
* also remove the check for xl_len == 0 in ReadRecord, below.
*/
- if (len == 0 || len > MAXLOGRECSZ)
+ if (len == 0)
elog(PANIC, "invalid xlog record length %u", len);
START_CRIT_SECTION();
@@ -745,14 +747,6 @@ begin:;
/* Insert record header */
record->xl_prev = Insert->PrevRecord;
- if (no_tran)
- {
- record->xl_xact_prev.xlogid = 0;
- record->xl_xact_prev.xrecoff = 0;
- }
- else
- record->xl_xact_prev = MyLastRecPtr;
-
record->xl_xid = GetCurrentTransactionId();
record->xl_len = len; /* doesn't include backup blocks */
record->xl_info = info;
@@ -2316,14 +2310,14 @@ RecordIsValid(XLogRecord *record, XLogRecPtr recptr, int emode)
* If no valid record is available, returns NULL, or fails if emode is PANIC.
* (emode must be either PANIC or LOG.)
*
- * buffer is a workspace at least _INTL_MAXLOGRECSZ bytes long. It is needed
- * to reassemble a record that crosses block boundaries. Note that on
- * successful return, the returned record pointer always points at buffer.
+ * The record is copied into readRecordBuf, so that on successful return,
+ * the returned record pointer always points there.
*/
static XLogRecord *
-ReadRecord(XLogRecPtr *RecPtr, int emode, char *buffer)
+ReadRecord(XLogRecPtr *RecPtr, int emode)
{
XLogRecord *record;
+ char *buffer;
XLogRecPtr tmpRecPtr = EndRecPtr;
bool randAccess = false;
uint32 len,
@@ -2467,6 +2461,13 @@ got_record:;
RecPtr->xlogid, RecPtr->xrecoff)));
goto next_record_is_invalid;
}
+ if (record->xl_rmid > RM_MAX_ID)
+ {
+ ereport(emode,
+ (errmsg("invalid resource manager ID %u at %X/%X",
+ record->xl_rmid, RecPtr->xlogid, RecPtr->xrecoff)));
+ goto next_record_is_invalid;
+ }
/*
* Compute total length of record including any appended backup
@@ -2481,24 +2482,34 @@ got_record:;
}
/*
- * Make sure it will fit in buffer (currently, it is mechanically
- * impossible for this test to fail, but it seems like a good idea
- * anyway).
+ * Allocate or enlarge readRecordBuf as needed. To avoid useless
+ * small increases, round its size to a multiple of BLCKSZ, and make
+ * sure it's at least 4*BLCKSZ to start with. (That is enough for
+ * all "normal" records, but very large commit or abort records might
+ * need more space.)
*/
- if (total_len > _INTL_MAXLOGRECSZ)
- {
- ereport(emode,
- (errmsg("record length %u at %X/%X too long",
- total_len, RecPtr->xlogid, RecPtr->xrecoff)));
- goto next_record_is_invalid;
- }
- if (record->xl_rmid > RM_MAX_ID)
+ if (total_len > readRecordBufSize)
{
- ereport(emode,
- (errmsg("invalid resource manager ID %u at %X/%X",
- record->xl_rmid, RecPtr->xlogid, RecPtr->xrecoff)));
- goto next_record_is_invalid;
+ uint32 newSize = total_len;
+
+ newSize += BLCKSZ - (newSize % BLCKSZ);
+ newSize = Max(newSize, 4 * BLCKSZ);
+ if (readRecordBuf)
+ free(readRecordBuf);
+ readRecordBuf = (char *) malloc(newSize);
+ if (!readRecordBuf)
+ {
+ readRecordBufSize = 0;
+ /* We treat this as a "bogus data" condition */
+ ereport(emode,
+ (errmsg("record length %u at %X/%X too long",
+ total_len, RecPtr->xlogid, RecPtr->xrecoff)));
+ goto next_record_is_invalid;
+ }
+ readRecordBufSize = newSize;
}
+
+ buffer = readRecordBuf;
nextRecord = NULL;
len = BLCKSZ - RecPtr->xrecoff % BLCKSZ;
if (total_len > len)
@@ -3481,8 +3492,6 @@ BootStrapXLOG(void)
record = (XLogRecord *) ((char *) page + SizeOfXLogLongPHD);
record->xl_prev.xlogid = 0;
record->xl_prev.xrecoff = 0;
- record->xl_xact_prev.xlogid = 0;
- record->xl_xact_prev.xrecoff = 0;
record->xl_xid = InvalidTransactionId;
record->xl_len = sizeof(checkPoint);
record->xl_info = XLOG_CHECKPOINT_SHUTDOWN;
@@ -3981,12 +3990,8 @@ StartupXLOG(void)
uint32 endLogId;
uint32 endLogSeg;
XLogRecord *record;
- char *buffer;
uint32 freespace;
- /* Use malloc() to ensure record buffer is MAXALIGNED */
- buffer = (char *) malloc(_INTL_MAXLOGRECSZ);
-
CritSectionCount++;
/*
@@ -4063,7 +4068,7 @@ StartupXLOG(void)
* from the checkpoint it identifies, rather than using
* pg_control.
*/
- record = ReadCheckpointRecord(checkPointLoc, 0, buffer);
+ record = ReadCheckpointRecord(checkPointLoc, 0);
if (record != NULL)
{
ereport(LOG,
@@ -4085,7 +4090,7 @@ StartupXLOG(void)
* according to pg_control is broken, try the next-to-last one.
*/
checkPointLoc = ControlFile->checkPoint;
- record = ReadCheckpointRecord(checkPointLoc, 1, buffer);
+ record = ReadCheckpointRecord(checkPointLoc, 1);
if (record != NULL)
{
ereport(LOG,
@@ -4095,7 +4100,7 @@ StartupXLOG(void)
else
{
checkPointLoc = ControlFile->prevCheckPoint;
- record = ReadCheckpointRecord(checkPointLoc, 2, buffer);
+ record = ReadCheckpointRecord(checkPointLoc, 2);
if (record != NULL)
{
ereport(LOG,
@@ -4198,12 +4203,12 @@ StartupXLOG(void)
if (XLByteLT(checkPoint.redo, RecPtr))
{
/* back up to find the record */
- record = ReadRecord(&(checkPoint.redo), PANIC, buffer);
+ record = ReadRecord(&(checkPoint.redo), PANIC);
}
else
{
/* just have to read next record after CheckPoint */
- record = ReadRecord(NULL, LOG, buffer);
+ record = ReadRecord(NULL, LOG);
}
if (record != NULL)
@@ -4263,7 +4268,7 @@ StartupXLOG(void)
LastRec = ReadRecPtr;
- record = ReadRecord(NULL, LOG, buffer);
+ record = ReadRecord(NULL, LOG);
} while (record != NULL && recoveryContinue);
/*
@@ -4287,7 +4292,7 @@ StartupXLOG(void)
* Re-fetch the last valid or last applied record, so we can identify
* the exact endpoint of what we consider the valid portion of WAL.
*/
- record = ReadRecord(&LastRec, PANIC, buffer);
+ record = ReadRecord(&LastRec, PANIC);
EndOfLog = EndRecPtr;
XLByteToPrevSeg(EndOfLog, endLogId, endLogSeg);
@@ -4404,7 +4409,7 @@ StartupXLOG(void)
RecPtr.xlogid, RecPtr.xrecoff)));
do
{
- record = ReadRecord(&RecPtr, PANIC, buffer);
+ record = ReadRecord(&RecPtr, PANIC);
if (TransactionIdIsValid(record->xl_xid) &&
!TransactionIdDidCommit(record->xl_xid))
RmgrTable[record->xl_rmid].rm_undo(EndRecPtr, record);
@@ -4498,8 +4503,12 @@ StartupXLOG(void)
free(readBuf);
readBuf = NULL;
}
-
- free(buffer);
+ if (readRecordBuf)
+ {
+ free(readRecordBuf);
+ readRecordBuf = NULL;
+ readRecordBufSize = 0;
+ }
}
/*
@@ -4509,9 +4518,7 @@ StartupXLOG(void)
* 1 for "primary", 2 for "secondary", 0 for "other" (backup_label)
*/
static XLogRecord *
-ReadCheckpointRecord(XLogRecPtr RecPtr,
- int whichChkpt,
- char *buffer)
+ReadCheckpointRecord(XLogRecPtr RecPtr, int whichChkpt)
{
XLogRecord *record;
@@ -4535,7 +4542,7 @@ ReadCheckpointRecord(XLogRecPtr RecPtr,
return NULL;
}
- record = ReadRecord(&RecPtr, LOG, buffer);
+ record = ReadRecord(&RecPtr, LOG);
if (record == NULL)
{
@@ -5080,9 +5087,8 @@ xlog_outrec(char *buf, XLogRecord *record)
int bkpb;
int i;
- sprintf(buf + strlen(buf), "prev %X/%X; xprev %X/%X; xid %u",
+ sprintf(buf + strlen(buf), "prev %X/%X; xid %u",
record->xl_prev.xlogid, record->xl_prev.xrecoff,
- record->xl_xact_prev.xlogid, record->xl_xact_prev.xrecoff,
record->xl_xid);
for (i = 0, bkpb = 0; i < XLR_MAX_BKP_BLOCKS; i++)
generated by cgit v1.2.3 (git 2.46.0) at 2025-08-16 22:26:03 +0000