aboutsummaryrefslogtreecommitdiff
path: root/block
diff options
context:
space:
mode:
authorTejun Heo <htejun@gmail.com>2006-01-12 15:39:26 +0100
committerLinus Torvalds <torvalds@g5.osdl.org>2006-01-12 09:05:39 -0800
commit1bc691d357c646700b9523d2aeca02847d3fb3f4 (patch)
tree430e13982f894c44e4a33dee188b3c718ec989ed /block
parent593195f9b2309693f27b402f34573f7920b82c3e (diff)
downloadlinux-2.6.34-ux500-1bc691d357c646700b9523d2aeca02847d3fb3f4.tar.gz
[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>
Diffstat (limited to 'block')
-rw-r--r--block/elevator.c20
1 files changed, 10 insertions, 10 deletions
diff --git a/block/elevator.c b/block/elevator.c
index 99a4d7b2f8a..1d0759178e4 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -610,23 +610,23 @@ void elv_completed_request(request_queue_t *q, struct request *rq)
* request is released from the driver, io must be done
*/
if (blk_account_rq(rq)) {
- struct request *first_rq = list_entry_rq(q->queue_head.next);
-
q->in_flight--;
+ if (blk_sorted_rq(rq) && e->ops->elevator_completed_req_fn)
+ e->ops->elevator_completed_req_fn(q, rq);
+ }
- /*
- * Check if the queue is waiting for fs requests to be
- * drained for flush sequence.
- */
- if (q->ordseq && q->in_flight == 0 &&
+ /*
+ * Check if the queue is waiting for fs requests to be
+ * drained for flush sequence.
+ */
+ if (unlikely(q->ordseq)) {
+ struct request *first_rq = list_entry_rq(q->queue_head.next);
+ if (q->in_flight == 0 &&
blk_ordered_cur_seq(q) == QUEUE_ORDSEQ_DRAIN &&
blk_ordered_req_seq(first_rq) > QUEUE_ORDSEQ_DRAIN) {
blk_ordered_complete_seq(q, QUEUE_ORDSEQ_DRAIN, 0);
q->request_fn(q);
}
-
- if (blk_sorted_rq(rq) && e->ops->elevator_completed_req_fn)
- e->ops->elevator_completed_req_fn(q, rq);
}
}