conf/59065: /tmp/.X0-lock is not removed if clear_tmp_enable is not enabled

[Eric van Gyzen]

The following reply was made to PR conf/59065; it has been noted by GNATS.

From: Eric van Gyzen <vangyzen at stat.duke.edu>
To: Kris Kennaway <kris at obsecurity.org>
Cc: FreeBSD-gnats-submit at FreeBSD.org
Subject: Re: conf/59065: /tmp/.X0-lock is not removed if clear_tmp_enable is not enabled
Date: Mon, 10 Nov 2003 12:59:39 -0500

 Kris Kennaway wrote:
 > On Sat, Nov 08, 2003 at 05:39:19PM -0500, Eric van Gyzen wrote:
 > > >Description:
 > > The /tmp/.X0-lock file is removed by /etc/rc.d/cleartmp, which runs only
 > > if the clear_tmp_enable variable is true.  The file should be removed on
 > > boot, unconditionally.
 >
 > I think you got precisely the behaviour you asked for.  Many
 > applications use /tmp for storage of lock files and other temporary
 > data - if you want them to restart correctly after a reboot, clear
 > /tmp.
 
 It's true that many applications -- and users -- use /tmp for storage of 
 various things...so many and so various, in fact, that clearing it at boot is 
 too drastic in some environments.  There might be plenty of reasons not to 
 clear /tmp; that's why it's not done by default.
 
 X is a well-known application that practically everyone uses, and there is no 
 imaginable reason NOT to remove the lock file.  It is a special case of a 
 lock file that just happens to be stored in /tmp.  If it were stored in 
 /var/run along with various other lock files (rpcbind.lock, ypbind.lock), it 
 would be removed unconditionally by the cleanvar rc script.  In fact, the old 
 rc system /did/ remove it unconditionally regardless of clear_tmp_enable:
 
   # Clearing /tmp at boot-time seems to have a long tradition.  It doesn't
   # help in any way for long-living systems, and it might accidentally
   # clobber files you would rather like to have preserved after a crash
 [snip]
   case ${clear_tmp_enable} in
 [snip]
   esac
 
   # Remove X lock files, since they will prevent you from restarting X11
   # after a system crash.
   #
   rm -f /tmp/.X*-lock
   rm -fr /tmp/.X11-unix
   mkdir -m 1777 /tmp/.X11-unix
 
 Eric
 
 -- 
 Eric van Gyzen                        Sr. Systems Programmer
 http://www.stat.duke.edu/~vangyzen/   ISDS, Duke University