tree 430e13982f894c44e4a33dee188b3c718ec989ed
parent 593195f9b2309693f27b402f34573f7920b82c3e
author Tejun Heo <htejun@gmail.com> 1137076766 +0100
committer Linus Torvalds <torvalds@g5.osdl.org> 1137085539 -0800

[PATCH] fix queue stalling while barrier sequencing

If ordered tag isn't supported, request ordering for barrier
sequencing is performed by queue draining, which basically hangs the
request queue until elv_completed_request() reports completion of all
previous fs requests.

The condition check in elv_completed_request() was only performed for
fs requests.  If a special request is queued between the last
to-be-drained request and the barrier sequence, draining is never
completed and the queue is stalled forever.

This patch moves the end-of-draining condition check such that it's
performed for all requests.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>