This is an updated and properly autoconf-guarded patch for this
previously reported issue:
"""
Jacek Drobiecki recently sent me a patch which stops postgresql to
actively violate the system limit of maximum open files
(RLIMIT_NOFILE) in src/backend/storage/file/fd.c, function
count_usable_fds().
This avoids irritating kernel logs (if system overstep violations are
enabled) and also the grsecurity alert when starting PostgreSQL.
"""
References:
http://archives.postgresql.org/pgsql-bugs/2004-05/msg00103.php
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=248967
I think we can put this into 8.4 or the first commit fest of 8.5.
Index: src/backend/storage/file/fd.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/storage/file/fd.c,v
retrieving revision 1.147
diff -u -3 -p -r1.147 fd.c
--- src/backend/storage/file/fd.c 12 Jan 2009 05:10:44 -0000 1.147
+++ src/backend/storage/file/fd.c 27 Feb 2009 12:45:25 -0000
@@ -45,6 +45,9 @@
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
+#ifdef HAVE_SYS_RESOURCE_H
+#include <sys/resource.h> /* for getrlimit */
+#endif
#include "miscadmin.h"
#include "access/xact.h"
@@ -361,15 +364,35 @@ count_usable_fds(int max_to_probe, int *
int used = 0;
int highestfd = 0;
int j;
+#ifdef HAVE_GETRLIMIT
+ struct rlimit rlim;
+ int getrlimit_status;
+#endif
size = 1024;
fd = (int *) palloc(size * sizeof(int));
+#ifdef HAVE_GETRLIMIT
+# ifdef RLIMIT_NOFILE /* most platforms use RLIMIT_NOFILE */
+ getrlimit_status = getrlimit(RLIMIT_NOFILE, &rlim);
+# else /* but BSD doesn't ... */
+ getrlimit_status = getrlimit(RLIMIT_OFILE, &rlim);
+# endif /* RLIMIT_NOFILE */
+ if (getrlimit_status != 0)
+ ereport(WARNING, (errmsg("getrlimit failed: %m")));
+#endif /* HAVE_GETRLIMIT */
+
/* dup until failure or probe limit reached */
for (;;)
{
int thisfd;
+#ifdef HAVE_GETRLIMIT
+ /* don't go beyond RLIMIT_NOFILE */
+ if (getrlimit_status == 0 && highestfd >= rlim.rlim_cur - 1)
+ break;
+#endif
+
thisfd = dup(0);
if (thisfd < 0)
{
