From 481a7d64790cd7ca61a8bbcbd9d017ce58e6fe39 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 14 Dec 2011 00:33:37 +0100 Subject: block: fix drain_all condition in blk_drain_queue() When trying to drain all requests, blk_drain_queue() checked only q->rq.count[]; however, this only tracks REQ_ALLOCED requests. This patch updates blk_drain_queue() such that it looks at all the counters and queues so that request_queue is actually empty on completion. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-core.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index b5ed4f4a8d96..c37e9e7c9d07 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -358,7 +358,8 @@ EXPORT_SYMBOL(blk_put_queue); void blk_drain_queue(struct request_queue *q, bool drain_all) { while (true) { - int nr_rqs; + bool drain = false; + int i; spin_lock_irq(q->queue_lock); @@ -368,14 +369,25 @@ void blk_drain_queue(struct request_queue *q, bool drain_all) __blk_run_queue(q); - if (drain_all) - nr_rqs = q->rq.count[0] + q->rq.count[1]; - else - nr_rqs = q->rq.elvpriv; + drain |= q->rq.elvpriv; + + /* + * Unfortunately, requests are queued at and tracked from + * multiple places and there's no single counter which can + * be drained. Check all the queues and counters. + */ + if (drain_all) { + drain |= !list_empty(&q->queue_head); + for (i = 0; i < 2; i++) { + drain |= q->rq.count[i]; + drain |= q->in_flight[i]; + drain |= !list_empty(&q->flush_queue[i]); + } + } spin_unlock_irq(q->queue_lock); - if (!nr_rqs) + if (!drain) break; msleep(10); } -- cgit v1.2.3-59-g8ed1b