| commit | 1ddeaea5338e280bf6ad194838a040ff2a13a9eb | |
| author | Jan Kara <jack@suse.cz> | |
| Thu, 5 May 2011 11:59:35 +0000 (5 13:59 +0200) | ||
| committer | Greg Kroah-Hartman <gregkh@suse.de> | |
| Fri, 3 Jun 2011 01:33:52 +0000 (3 10:33 +0900) | ||
| tree | dc7032b9556b5ed84c7341306ba8e4fc1e8a2562 | treesnapshot (tar.gz zip) |
| parent | d5994d14b3697d22117b2e3c91317c4bff87803a | commitdiff |
jbd: Fix forever sleeping process in do_get_write_access()
commit 2842bb20eed2e25cde5114298edc62c8883a1d9a upstream.
In do_get_write_access() we wait on BH_Unshadow bit for buffer to get
from shadow state. The waking code in journal_commit_transaction() has
a bug because it does not issue a memory barrier after the buffer is moved
from the shadow state and before wake_up_bit() is called. Thus a waitqueue
check can happen before the buffer is actually moved from the shadow state
and waiting process may never be woken. Fix the problem by issuing proper
barrier.
Reported-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 2842bb20eed2e25cde5114298edc62c8883a1d9a upstream.
In do_get_write_access() we wait on BH_Unshadow bit for buffer to get
from shadow state. The waking code in journal_commit_transaction() has
a bug because it does not issue a memory barrier after the buffer is moved
from the shadow state and before wake_up_bit() is called. Thus a waitqueue
check can happen before the buffer is actually moved from the shadow state
and waiting process may never be woken. Fix the problem by issuing proper
barrier.
Reported-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| fs/jbd/commit.c | diffblobblamehistory |