Movatterモバイル変換

[0]ホーム
URL:

Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

 Sign up
Appearance settings

Commit8f5500e

Browse files
committed
Make it reasonably safe to use pg_ctl to start the postmaster from a boot-time
script.To do this, have pg_ctl pass down its parent shell's PID in an environmentvariable PG_GRANDPARENT_PID, and teach CreateLockFile() to disregard that PIDas a false match if it finds it in postmaster.pid. This allows us to copewith one level of postgres-owned shell process even with pg_ctl in the way,so it's just as safe as starting the postmaster directly. You still have tobe careful about how you write the initscript though.Adjust the comments in contrib/start-scripts/ to not deprecate use ofpg_ctl. Also, fix the ROTATELOGS option in the OSX script, which wasindulging in exactly the sort of unsafe coding that renders this fixpointless :-(. A pipe inside the "sudo" will probably result in morethan one postgres-owned process hanging around.
1 parent0e3f0cb commit8f5500e

File tree

5 files changed

+77
-38
lines changed

5 files changed

+77
-38
lines changed

‎contrib/start-scripts/freebsd‎

Lines changed: 4 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -6,7 +6,7 @@
66
# Created through merger of the Linux start script by Ryan Kirkpatrick
77
# and the script in the FreeBSD ports collection.
88

9-
# $PostgreSQL: pgsql/contrib/start-scripts/freebsd,v 1.4 2004/10/01 18:30:21 tgl Exp $
9+
# $PostgreSQL: pgsql/contrib/start-scripts/freebsd,v 1.5 2009/08/27 16:59:38 tgl Exp $
1010

1111
## EDIT FROM HERE
1212

@@ -27,9 +27,9 @@ PGLOG="$PGDATA/serverlog"
2727
# The path that is to be used for the script
2828
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
2929

30-
# What to use to start up the postmaster (we do NOT use pg_ctl for this,
31-
#as it adds no value and can cause the postmaster to misrecognize a stale
32-
#lock file)
30+
# What to use to start up the postmaster. (If you want the script to wait
31+
#until the server has started, you could use "pg_ctl start -w" here.
32+
#But without -w, pg_ctl adds no value.)
3333
DAEMON="$prefix/bin/postmaster"
3434

3535
# What to use to shut down the postmaster

‎contrib/start-scripts/linux‎

Lines changed: 4 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -24,7 +24,7 @@
2424

2525
# Original author: Ryan Kirkpatrick <pgsql@rkirkpat.net>
2626

27-
# $PostgreSQL: pgsql/contrib/start-scripts/linux,v 1.8 2006/07/13 14:44:33 petere Exp $
27+
# $PostgreSQL: pgsql/contrib/start-scripts/linux,v 1.9 2009/08/27 16:59:38 tgl Exp $
2828

2929
## EDIT FROM HERE
3030

@@ -45,9 +45,9 @@ PGLOG="$PGDATA/serverlog"
4545
# The path that is to be used for the script
4646
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
4747

48-
# What to use to start up the postmaster (we do NOT use pg_ctl for this,
49-
#as it adds no value and can cause the postmaster to misrecognize a stale
50-
#lock file)
48+
# What to use to start up the postmaster. (If you want the script to wait
49+
#until the server has started, you could use "pg_ctl start -w" here.
50+
#But without -w, pg_ctl adds no value.)
5151
DAEMON="$prefix/bin/postmaster"
5252

5353
# What to use to shut down the postmaster

‎contrib/start-scripts/osx/PostgreSQL‎

Lines changed: 5 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -68,9 +68,9 @@ ROTATESEC="604800"
6868
# The path that is to be used for the script
6969
PATH="$prefix/bin:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin"
7070

71-
# What to use to start up the postmaster (we do NOT use pg_ctl for this,
72-
#as it adds no value and can cause the postmaster to misrecognize a stale
73-
#lock file)
71+
# What to use to start up the postmaster. (If you want the script to wait
72+
#until the server has started, you could use "pg_ctl start -w" here.
73+
#But without -w, pg_ctl adds no value.)
7474
DAEMON="$prefix/bin/postmaster"
7575

7676
# What to use to shut down the postmaster
@@ -85,7 +85,7 @@ StartService () {
8585
if ["${POSTGRESQL:=-NO-}"="-YES-" ];then
8686
ConsoleMessage"Starting PostgreSQL database server"
8787
if ["${ROTATELOGS}"="1" ];then
88-
sudo -u$PGUSER sh -c"${DAEMON} -D '${PGDATA}' 2>&1 |${LOGUTIL} '${PGLOG}'${ROTATESEC} &"
88+
sudo -u$PGUSER sh -c"${DAEMON} -D '${PGDATA}'&"2>&1|${LOGUTIL}'${PGLOG}'${ROTATESEC}&
8989
else
9090
sudo -u$PGUSER sh -c"${DAEMON} -D '${PGDATA}' &">>$PGLOG2>&1
9191
fi
@@ -104,7 +104,7 @@ RestartService () {
104104
sudo -u$PGUSER$PGCTL stop -D"$PGDATA" -s -m fast
105105
# should match StartService:
106106
if ["${ROTATELOGS}"="1" ];then
107-
sudo -u$PGUSER sh -c"${DAEMON} -D '${PGDATA}' 2>&1 |${LOGUTIL} '${PGLOG}'${ROTATESEC} &"
107+
sudo -u$PGUSER sh -c"${DAEMON} -D '${PGDATA}'&"2>&1|${LOGUTIL}'${PGLOG}'${ROTATESEC}&
108108
else
109109
sudo -u$PGUSER sh -c"${DAEMON} -D '${PGDATA}' &">>$PGLOG2>&1
110110
fi

‎src/backend/utils/init/miscinit.c‎

Lines changed: 48 additions & 24 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $PostgreSQL: pgsql/src/backend/utils/init/miscinit.c,v 1.176 2009/08/12 20:53:30 tgl Exp $
11+
* $PostgreSQL: pgsql/src/backend/utils/init/miscinit.c,v 1.177 2009/08/27 16:59:38 tgl Exp $
1212
*
1313
*-------------------------------------------------------------------------
1414
*/
@@ -683,7 +683,46 @@ CreateLockFile(const char *filename, bool amPostmaster,
683683
intlen;
684684
intencoded_pid;
685685
pid_tother_pid;
686-
pid_tmy_pid=getpid();
686+
pid_tmy_pid,
687+
my_p_pid,
688+
my_gp_pid;
689+
constchar*envvar;
690+
691+
/*
692+
* If the PID in the lockfile is our own PID or our parent's or
693+
* grandparent's PID, then the file must be stale (probably left over from
694+
* a previous system boot cycle). We need to check this because of the
695+
* likelihood that a reboot will assign exactly the same PID as we had in
696+
* the previous reboot, or one that's only one or two counts larger and
697+
* hence the lockfile's PID now refers to an ancestor shell process. We
698+
* allow pg_ctl to pass down its parent shell PID (our grandparent PID)
699+
* via the environment variable PG_GRANDPARENT_PID; this is so that
700+
* launching the postmaster via pg_ctl can be just as reliable as
701+
* launching it directly. There is no provision for detecting
702+
* further-removed ancestor processes, but if the init script is written
703+
* carefully then all but the immediate parent shell will be root-owned
704+
* processes and so the kill test will fail with EPERM. Note that we
705+
* cannot get a false negative this way, because an existing postmaster
706+
* would surely never launch a competing postmaster or pg_ctl process
707+
* directly.
708+
*/
709+
my_pid=getpid();
710+
711+
#ifndefWIN32
712+
my_p_pid=getppid();
713+
#else
714+
/*
715+
* Windows hasn't got getppid(), but doesn't need it since it's not
716+
* using real kill() either...
717+
*/
718+
my_p_pid=0;
719+
#endif
720+
721+
envvar=getenv("PG_GRANDPARENT_PID");
722+
if (envvar)
723+
my_gp_pid=atoi(envvar);
724+
else
725+
my_gp_pid=0;
687726

688727
/*
689728
* We need a loop here because of race conditions.But don't loop forever
@@ -745,17 +784,11 @@ CreateLockFile(const char *filename, bool amPostmaster,
745784
/*
746785
* Check to see if the other process still exists
747786
*
748-
* If the PID in the lockfile is our own PID or our parent's PID, then
749-
* the file must be stale (probably left over from a previous system
750-
* boot cycle). We need this test because of the likelihood that a
751-
* reboot will assign exactly the same PID as we had in the previous
752-
* reboot.Also, if there is just one more process launch in this
753-
* reboot than in the previous one, the lockfile might mention our
754-
* parent's PID. We can reject that since we'd never be launched
755-
* directly by a competing postmaster.We can't detect grandparent
756-
* processes unfortunately, but if the init script is written
757-
* carefully then all but the immediate parent shell will be
758-
* root-owned processes and so the kill test will fail with EPERM.
787+
* Per discussion above, my_pid, my_p_pid, and my_gp_pid can be
788+
* ignored as false matches.
789+
*
790+
* Normally kill() will fail with ESRCH if the given PID doesn't
791+
* exist.
759792
*
760793
* We can treat the EPERM-error case as okay because that error
761794
* implies that the existing process has a different userid than we
@@ -772,18 +805,9 @@ CreateLockFile(const char *filename, bool amPostmaster,
772805
* Unix socket file belonging to an instance of Postgres being run by
773806
* someone else, at least on machines where /tmp hasn't got a
774807
* stickybit.)
775-
*
776-
* Windows hasn't got getppid(), but doesn't need it since it's not
777-
* using real kill() either...
778-
*
779-
* Normally kill() will fail with ESRCH if the given PID doesn't
780-
* exist.
781808
*/
782-
if (other_pid!=my_pid
783-
#ifndefWIN32
784-
&&other_pid!=getppid()
785-
#endif
786-
)
809+
if (other_pid!=my_pid&&other_pid!=my_p_pid&&
810+
other_pid!=my_gp_pid)
787811
{
788812
if (kill(other_pid,0)==0||
789813
(errno!=ESRCH&&errno!=EPERM))

‎src/bin/pg_ctl/pg_ctl.c‎

Lines changed: 16 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -4,7 +4,7 @@
44
*
55
* Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
66
*
7-
* $PostgreSQL: pgsql/src/bin/pg_ctl/pg_ctl.c,v 1.111 2009/06/11 14:49:07 momjian Exp $
7+
* $PostgreSQL: pgsql/src/bin/pg_ctl/pg_ctl.c,v 1.112 2009/08/27 16:59:38 tgl Exp $
88
*
99
*-------------------------------------------------------------------------
1010
*/
@@ -672,6 +672,21 @@ do_start(void)
672672
unlimit_core_size();
673673
#endif
674674

675+
/*
676+
* If possible, tell the postmaster our parent shell's PID (see the
677+
* comments in CreateLockFile() for motivation). Windows hasn't got
678+
* getppid() unfortunately.
679+
*/
680+
#ifndefWIN32
681+
{
682+
staticcharenv_var[32];
683+
684+
snprintf(env_var,sizeof(env_var),"PG_GRANDPARENT_PID=%d",
685+
(int)getppid());
686+
putenv(env_var);
687+
}
688+
#endif
689+
675690
exitcode=start_postmaster();
676691
if (exitcode!=0)
677692
{

0 commit comments

Comments
 (0)
[8]ページ先頭
©2009-2025 Movatter.jp