If we queue a work item that calls iput(), make sure we ihold() before
attempting to queue work. Otherwise our queued work might miraculously run
before we notice the queue_work() succeeded and call ihold(), allowing the
inode to be destroyed.
That is, instead of
if (queue_work(...))
ihold();
we need to do
ihold();
if (!queue_work(...))
iput();
Reported-by: Amon Ott <a.ott@m-privacy.de>
Signed-off-by: Sage Weil <sage@newdream.net>