From 80727ce14fe61a66e840d663e3b7d12c0a8380ad Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Sat, 25 Jan 2003 03:06:04 +0000
Subject: [PATCH] Use stat(2) to probe for existing xlog segments in
InstallXLogFileSegment, rather than actually opening the files. This
eliminates some corner cases where the file indeed exists but open() fails
for another reason, such as being out of file descriptors. The net
reliability gain is probably tiny, since xlog.c is full of other file open
calls that will elog(PANIC) if they fail for any reason; but this specific
failure mode has been observed in the field, so we may as well fix it.
---
src/backend/access/transam/xlog.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index a78533c389..c35762bba9 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Header: /cvsroot/pgsql/src/backend/access/transam/xlog.c,v 1.110 2002/11/08 20:23:56 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/access/transam/xlog.c,v 1.111 2003/01/25 03:06:04 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -1471,7 +1471,7 @@ InstallXLogFileSegment(uint32 log, uint32 seg, char *tmppath,
bool use_lock)
{
char path[MAXPGPATH];
- int fd;
+ struct stat stat_buf;
XLogFileName(path, log, seg);
@@ -1489,10 +1489,8 @@ InstallXLogFileSegment(uint32 log, uint32 seg, char *tmppath,
else
{
/* Find a free slot to put it in */
- while ((fd = BasicOpenFile(path, O_RDWR | PG_BINARY,
- S_IRUSR | S_IWUSR)) >= 0)
+ while (stat(path, &stat_buf) == 0)
{
- close(fd);
if (--max_advance < 0)
{
/* Failed to find a free slot within specified range */