blk_mq_drain_queue() is introduced so that we can drain mq queue during cleanup queue.
Also don't accept new requests any more if queue is marked as dying. Cc: Jens Axboe <[email protected]> Signed-off-by: Ming Lei <[email protected]> --- block/blk-core.c | 13 +++++++++---- block/blk-mq.c | 24 +++++++++++++++++++++--- block/blk-mq.h | 1 + 3 files changed, 31 insertions(+), 7 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 5da8e90..eb13db0 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -38,6 +38,7 @@ #include "blk.h" #include "blk-cgroup.h" +#include "blk-mq.h" EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_remap); EXPORT_TRACEPOINT_SYMBOL_GPL(block_rq_remap); @@ -497,10 +498,14 @@ void blk_cleanup_queue(struct request_queue *q) * Drain all requests queued before DYING marking. Set DEAD flag to * prevent that q->request_fn() gets invoked after draining finished. */ - spin_lock_irq(lock); - __blk_drain_queue(q, true); - queue_flag_set(QUEUE_FLAG_DEAD, q); - spin_unlock_irq(lock); + if (q->mq_ops) { + blk_mq_drain_queue(q); + } else { + spin_lock_irq(lock); + __blk_drain_queue(q, true); + queue_flag_set(QUEUE_FLAG_DEAD, q); + spin_unlock_irq(lock); + } /* @q won't process any more request, flush async actions */ del_timer_sync(&q->backing_dev_info.laptop_mode_wb_timer); diff --git a/block/blk-mq.c b/block/blk-mq.c index 53dc9f7..fcfdf35 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -104,10 +104,13 @@ static int blk_mq_queue_enter(struct request_queue *q) spin_lock_irq(q->queue_lock); ret = wait_event_interruptible_lock_irq(q->mq_freeze_wq, - !blk_queue_bypass(q), *q->queue_lock); + !blk_queue_bypass(q) || blk_queue_dying(q), + *q->queue_lock); /* inc usage with lock hold to avoid freeze_queue runs here */ - if (!ret) + if (!ret && !blk_queue_dying(q)) __percpu_counter_add(&q->mq_usage_counter, 1, 1000000); + else if (blk_queue_dying(q)) + ret = -ENODEV; spin_unlock_irq(q->queue_lock); return ret; @@ -122,10 +125,14 @@ static void blk_mq_queue_exit(struct request_queue *q) * Guarantee no request is in use, so we can change any data structure of * the queue afterward. */ -static void blk_mq_freeze_queue(struct request_queue *q) +static void __blk_mq_freeze_queue(struct request_queue *q, + bool force_drain) { bool drain; + if (force_drain) + goto do_drain; + spin_lock_irq(q->queue_lock); drain = !q->bypass_depth++; queue_flag_set(QUEUE_FLAG_BYPASS, q); @@ -134,6 +141,7 @@ static void blk_mq_freeze_queue(struct request_queue *q) if (!drain) return; + do_drain: while (true) { s64 count; @@ -148,6 +156,16 @@ static void blk_mq_freeze_queue(struct request_queue *q) } } +static void blk_mq_freeze_queue(struct request_queue *q) +{ + __blk_mq_freeze_queue(q, false); +} + +void blk_mq_drain_queue(struct request_queue *q) +{ + __blk_mq_freeze_queue(q, true); +} + static void blk_mq_unfreeze_queue(struct request_queue *q) { bool wake = false; diff --git a/block/blk-mq.h b/block/blk-mq.h index 5761eed..35ff4f7 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -27,6 +27,7 @@ void blk_mq_complete_request(struct request *rq, int error); void blk_mq_run_request(struct request *rq, bool run_queue, bool async); void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async); void blk_mq_init_flush(struct request_queue *q); +void blk_mq_drain_queue(struct request_queue *q); /* * CPU hotplug helpers -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
