Messages in this thread Patch in this message | | | From | Tejun Heo <> | Subject | [PATCH 5/6] block: fix drain_all condition in blk_drain_queue() | Date | Tue, 25 Oct 2011 18:02:06 -0700 |
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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 <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> --- block/blk-core.c | 24 ++++++++++++++++++------ 1 files changed, 18 insertions(+), 6 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c index 7d39897..4224e0a 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); } -- 1.7.3.1
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