cgroup: fix root_count when mount fails due to busy subsystem
authorPaul Menage <menage@google.com>
Thu, 29 Jan 2009 22:25:22 +0000 (14:25 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 30 Jan 2009 02:04:45 +0000 (18:04 -0800)
commit839ec5452ebfd5905b9c69b20ceb640903a8ea1a
tree42e371a4230c50c3cb34c92e80f5fa199b01dd2b
parent804b3c28a4e4fa1c224571bf76edb534b9c4b1ed
cgroup: fix root_count when mount fails due to busy subsystem

root_count was being incremented in cgroup_get_sb() after all error
checking was complete, but decremented in cgroup_kill_sb(), which can be
called on a superblock that we gave up on due to an error.  This patch
changes cgroup_kill_sb() to only decrement root_count if the root was
previously linked into the list of roots.

Signed-off-by: Paul Menage <menage@google.com>
Tested-by: Serge Hallyn <serue@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kernel/cgroup.c