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ocfs2: fix posix_acl_create deadlock
authorJunxiao Bi <junxiao.bi@oracle.com>
Thu, 12 May 2016 22:42:18 +0000 (15:42 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 19 May 2016 00:06:44 +0000 (17:06 -0700)
commitdc3e6de00b00bb7b716d2653650fdd112e981578
tree0192b9dcafd6dd16289902b532eb1e0eb4991c19
parent3cbabd4e83f63d5271c8ff74c059f7cbe85c4c1d
ocfs2: fix posix_acl_create deadlock

commit c25a1e0671fbca7b2c0d0757d533bd2650d6dc0c upstream.

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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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