Don't actively violate the system limit of maximum open files (RLIMIT_NOFILE).

This avoids irritating kernel logs (if system overstep violations are enabled)
and also the grsecurity alert when starting PostgreSQL.

original patch by Jacek Drobiecki

References:
http://archives.postgresql.org/pgsql-bugs/2004-05/msg00103.php
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=248967
This commit is contained in:
Peter Eisentraut 2009-03-04 09:12:49 +00:00
parent a2e9de79a6
commit 9add9f95c3

View File

@ -7,7 +7,7 @@
* Portions Copyright (c) 1994, Regents of the University of California * Portions Copyright (c) 1994, Regents of the University of California
* *
* IDENTIFICATION * IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/storage/file/fd.c,v 1.147 2009/01/12 05:10:44 tgl Exp $ * $PostgreSQL: pgsql/src/backend/storage/file/fd.c,v 1.148 2009/03/04 09:12:49 petere Exp $
* *
* NOTES: * NOTES:
* *
@ -45,6 +45,9 @@
#include <sys/stat.h> #include <sys/stat.h>
#include <unistd.h> #include <unistd.h>
#include <fcntl.h> #include <fcntl.h>
#ifdef HAVE_SYS_RESOURCE_H
#include <sys/resource.h> /* for getrlimit */
#endif
#include "miscadmin.h" #include "miscadmin.h"
#include "access/xact.h" #include "access/xact.h"
@ -361,15 +364,35 @@ count_usable_fds(int max_to_probe, int *usable_fds, int *already_open)
int used = 0; int used = 0;
int highestfd = 0; int highestfd = 0;
int j; int j;
#ifdef HAVE_GETRLIMIT
struct rlimit rlim;
int getrlimit_status;
#endif
size = 1024; size = 1024;
fd = (int *) palloc(size * sizeof(int)); 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 */ /* dup until failure or probe limit reached */
for (;;) for (;;)
{ {
int thisfd; int thisfd;
#ifdef HAVE_GETRLIMIT
/* don't go beyond RLIMIT_NOFILE; causes irritating kernel logs on some platforms */
if (getrlimit_status == 0 && highestfd >= rlim.rlim_cur - 1)
break;
#endif
thisfd = dup(0); thisfd = dup(0);
if (thisfd < 0) if (thisfd < 0)
{ {