ocfs2: fix BUG in ocfs2_downconvert_thread_do_work()
authorJoseph Qi <joseph.qi@huawei.com>
Thu, 6 Aug 2015 22:46:23 +0000 (15:46 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 7 Aug 2015 01:39:40 +0000 (04:39 +0300)
commit209f7512d007980fd111a74a064d70a3656079cf
tree0b12e03001248c15a79286d66caa295c33d2dbd7
parent4248b0da460839e30eaaad78992b9a1dd3e63e21
ocfs2: fix BUG in ocfs2_downconvert_thread_do_work()

The "BUG_ON(list_empty(&osb->blocked_lock_list))" in
ocfs2_downconvert_thread_do_work can be triggered in the following case:

ocfs2dc has firstly saved osb->blocked_lock_count to local varibale
processed, and then processes the dentry lockres.  During the dentry
put, it calls iput and then deletes rw, inode and open lockres from
blocked list in ocfs2_mark_lockres_freeing.  And this causes the
variable `processed' to not reflect the number of blocked lockres to be
processed, which triggers the BUG.

Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
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/dlmglue.c