openrc/sh/rc-mount.sh
William Hubbs 6794441224 Make fuser command time out
This avoids situations in which fuser hangs because of open files on
remote file systems when the remote system goes down.
I have also passed this bug on to the maintainers of psmisc since it
should really be fixed in fuser.
This is based on a patch submitted by evermind@tuxfamily.org

Reported-by: evermind@tuxfamily.org
X-Gentoo-Bug: 455458
X-Gentoo-Bug-URL: https://bugs.gentoo.org/show_bug.cgi?id=455458
2013-03-12 12:57:44 -05:00

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# Copyright (c) 2007-2009 Roy Marples <roy@marples.name>
# Released under the 2-clause BSD license.
# Declare this here so that no formatting doesn't affect the embedded newline
__IFS="
"
# Handy function to handle all our unmounting needs
# mountinfo is a C program to actually find our mounts on our supported OS's
# We rely on fuser being present, so if it's not then don't unmount anything.
# This isn't a real issue for the BSD's, but it is for Linux.
do_unmount()
{
local cmd="$1" retval=0 retry= pids=-
local f_opts="-m -c" f_kill="-s " mnt=
if [ "$RC_UNAME" = "Linux" ]; then
f_opts="-m"
f_kill="-"
fi
shift
local IFS="$__IFS"
set -- $(mountinfo "$@")
unset IFS
for mnt; do
# Unmounting a shared mount can unmount other mounts, so
# we need to check the mount is still valid
mountinfo --quiet "$mnt" || continue
# Ensure we interpret all characters properly.
mnt=$(printf "$mnt")
case "$cmd" in
umount)
ebegin "Unmounting $mnt"
;;
*)
ebegin "Remounting $mnt read only"
;;
esac
retry=4 # Effectively TERM, sleep 1, TERM, sleep 1, KILL, sleep 1
while ! LC_ALL=C $cmd "$mnt" 2>/dev/null; do
if type fuser >/dev/null 2>&1; then
pids="$(timeout -k 10 -s KILL "${rc_fuser_timeout:-60}" \
fuser $f_opts "$mnt" 2>/dev/null)"
fi
case " $pids " in
*" $$ "*)
eend 1 "failed because we are using" \
"$mnt"
retry=0;;
" - ")
eend 1
retry=0;;
" ")
eend 1 "in use but fuser finds nothing"
retry=0;;
*)
if [ $retry -le 0 ]; then
eend 1
else
local sig="TERM"
: $(( retry -= 1 ))
[ $retry = 1 ] && sig="KILL"
fuser $f_kill$sig -k $f_opts \
"$mnt" >/dev/null 2>&1
sleep 1
fi
;;
esac
[ $retry -le 0 ] && break
done
if [ $retry -le 0 ]; then
retval=1
else
eend 0
fi
done
return $retval
}