ocfs2: fix posix_acl_create deadlock
authorJunxiao Bi <junxiao.bi@oracle.com>
Thu, 12 May 2016 22:42:18 +0000 (15:42 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 12 May 2016 22:52:50 +0000 (15:52 -0700)
commitc25a1e0671fbca7b2c0d0757d533bd2650d6dc0c
tree568387253124f7f9aa738aea26f7964d048aa70b
parent5ee0fbd50fdf1c1329de8bee35ea9d7c6a81a2e0
ocfs2: fix posix_acl_create deadlock

Commit 702e5bc68ad2 ("ocfs2: use generic posix ACL infrastructure")
refactored code to use posix_acl_create.  The problem with this function
is that it is not mindful of the cluster wide inode lock making it
unsuitable for use with ocfs2 inode creation with ACLs.  For example,
when used in ocfs2_mknod, this function can cause deadlock as follows.
The parent dir inode lock is taken when calling posix_acl_create ->
get_acl -> ocfs2_iop_get_acl which takes the inode lock again.  This can
cause deadlock if there is a blocked remote lock request waiting for the
lock to be downconverted.  And same deadlock happened in ocfs2_reflink.
This fix is to revert back using ocfs2_init_acl.

Fixes: 702e5bc68ad2 ("ocfs2: use generic posix ACL infrastructure")
Signed-off-by: Tariq Saeed <tariq.x.saeed@oracle.com>
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/ocfs2/acl.c
fs/ocfs2/acl.h
fs/ocfs2/namei.c
fs/ocfs2/refcounttree.c
fs/ocfs2/xattr.c
fs/ocfs2/xattr.h