database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-09-02 04:21:28 +03:00
Code Activity

Remove XLogFileNameP() from the tree

Browse Source 
XLogFileNameP() is a wrapper routine able to build a palloc'd string for
a WAL segment name, which is used for error string generation.  There
were several code paths where it gets called in a critical section,
where memory allocation is not allowed.  This results in triggering
an assertion failure instead of generating the wanted error message.

Another, more annoying, problem is that if the allocation to generate
the WAL segment name fails on OOM, then the failure would be escalated
to a PANIC.

This removes the routine and all its callers are replaced with a logic
using a fixed-size buffer.  This way, all the existing mistakes are
fixed and future ones are prevented.

Author: Masahiko Sawada
Reviewed-by: Michael Paquier, Álvaro Herrera
Discussion: https://postgr.es/m/CA+fd4k5gC9H4uoWMLg9K_QfNrnkkdEw+-AFveob9YX7z8JnKTA@mail.gmail.com
This commit is contained in:
Michael Paquier
2019-12-03 15:06:04 +09:00
parent e5532f194c
commit 9989d37d1c
6 changed files with 96 additions and 44 deletions
Download Patch File Download Diff File Expand all files Collapse all files

30
src/backend/replication/walreceiver.c
View File

@@ -576,17 +576,17 @@ WalReceiverMain(void)
char xlogfname[MAXFNAMELEN];
XLogWalRcvFlush(false);
XLogFileName(xlogfname, recvFileTLI, recvSegNo, wal_segment_size);
if (close(recvFile) != 0)
ereport(PANIC,
(errcode_for_file_access(),
errmsg("could not close log segment %s: %m",
XLogFileNameP(recvFileTLI, recvSegNo))));
xlogfname)));
/*
* Create .done file forcibly to prevent the streamed segment from
* being archived later.
*/
XLogFileName(xlogfname, recvFileTLI, recvSegNo, wal_segment_size);
if (XLogArchiveMode != ARCHIVE_MODE_ALWAYS)
XLogArchiveForceDone(xlogfname);
else
@@ -900,6 +900,8 @@ XLogWalRcvWrite(char *buf, Size nbytes, XLogRecPtr recptr)
XLogWalRcvFlush(false);
XLogFileName(xlogfname, recvFileTLI, recvSegNo, wal_segment_size);
/*
* XLOG segment files will be re-read by recovery in startup
* process soon, so we don't advise the OS to release cache
@@ -909,13 +911,12 @@ XLogWalRcvWrite(char *buf, Size nbytes, XLogRecPtr recptr)
ereport(PANIC,
(errcode_for_file_access(),
errmsg("could not close log segment %s: %m",
XLogFileNameP(recvFileTLI, recvSegNo))));
xlogfname)));
/*
* Create .done file forcibly to prevent the streamed segment
* from being archived later.
*/
XLogFileName(xlogfname, recvFileTLI, recvSegNo, wal_segment_size);
if (XLogArchiveMode != ARCHIVE_MODE_ALWAYS)
XLogArchiveForceDone(xlogfname);
else
@@ -943,11 +944,18 @@ XLogWalRcvWrite(char *buf, Size nbytes, XLogRecPtr recptr)
if (recvOff != startoff)
{
if (lseek(recvFile, (off_t) startoff, SEEK_SET) < 0)
{
char xlogfname[MAXFNAMELEN];
int save_errno = errno;
XLogFileName(xlogfname, recvFileTLI, recvSegNo, wal_segment_size);
errno = save_errno;
ereport(PANIC,
(errcode_for_file_access(),
errmsg("could not seek in log segment %s to offset %u: %m",
XLogFileNameP(recvFileTLI, recvSegNo),
startoff)));
xlogfname, startoff)));
}
recvOff = startoff;
}
@@ -957,15 +965,21 @@ XLogWalRcvWrite(char *buf, Size nbytes, XLogRecPtr recptr)
byteswritten = write(recvFile, buf, segbytes);
if (byteswritten <= 0)
{
char xlogfname[MAXFNAMELEN];
int save_errno;
/* if write didn't set errno, assume no disk space */
if (errno == 0)
errno = ENOSPC;
save_errno = errno;
XLogFileName(xlogfname, recvFileTLI, recvSegNo, wal_segment_size);
errno = save_errno;
ereport(PANIC,
(errcode_for_file_access(),
errmsg("could not write to log segment %s "
"at offset %u, length %lu: %m",
XLogFileNameP(recvFileTLI, recvSegNo),
recvOff, (unsigned long) segbytes)));
xlogfname, recvOff, (unsigned long) segbytes)));
}
/* Update state for write */

9
src/backend/replication/walsender.c
View File

@@ -2434,10 +2434,17 @@ WalSndSegmentOpen(XLogSegNo nextSegNo, WALSegmentContext *segcxt,
* too old WAL segment that has already been removed or recycled.
*/
if (errno == ENOENT)
{
char xlogfname[MAXFNAMELEN];
int save_errno = errno;
XLogFileName(xlogfname, *tli_p, nextSegNo, wal_segment_size);
errno = save_errno;
ereport(ERROR,
(errcode_for_file_access(),
errmsg("requested WAL segment %s has already been removed",
XLogFileNameP(*tli_p, nextSegNo))));
xlogfname)));
}
else
ereport(ERROR,
(errcode_for_file_access(),