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| author |   Ming Lei <ming.lei@redhat.com> | 2017-06-06 23:22:08 +0800 |
|---|---|---|
| committer |   Jens Axboe <axboe@kernel.dk> | 2017-06-18 14:24:48 -0600 |
| commit | 1d9e9bc6b56e1bb7e33e7e2e1b99d7088356c006 (patch) | |
| tree | 4a0929fa4e384718aabcc2180399b219f18f1615 /block | |
| parent | blk-mq: update comments on blk_mq_quiesce_queue() (diff) | |
| download | linux-dev-1d9e9bc6b56e1bb7e33e7e2e1b99d7088356c006.tar.xz linux-dev-1d9e9bc6b56e1bb7e33e7e2e1b99d7088356c006.zip | |
blk-mq: don't stop queue for quiescing
Queue can be started by other blk-mq APIs and can be used in
different cases, this limits uses of blk_mq_quiesce_queue()
if it is based on stopping queue, and make its usage very
difficult, especially users have to use the stop queue APIs
carefully for avoiding to break blk_mq_quiesce_queue().
We have applied the QUIESCED flag for draining and blocking
dispatch, so it isn't necessary to stop queue any more.
After stopping queue is removed, blk_mq_quiesce_queue() can
be used safely and easily, then users won't worry about queue
restarting during quiescing at all.
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-mq.c | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c index f2a73190f60d..dbae586602f6 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -169,11 +169,7 @@ void blk_mq_quiesce_queue(struct request_queue *q) unsigned int i; bool rcu = false; - __blk_mq_stop_hw_queues(q, true); - - spin_lock_irq(q->queue_lock); - queue_flag_set(QUEUE_FLAG_QUIESCED, q); - spin_unlock_irq(q->queue_lock); + blk_mq_quiesce_queue_nowait(q); queue_for_each_hw_ctx(q, hctx, i) { if (hctx->flags & BLK_MQ_F_BLOCKING) @@ -199,7 +195,8 @@ void blk_mq_unquiesce_queue(struct request_queue *q) queue_flag_clear(QUEUE_FLAG_QUIESCED, q); spin_unlock_irq(q->queue_lock); - blk_mq_start_stopped_hw_queues(q, true); + /* dispatch requests which are inserted during quiescing */ + blk_mq_run_hw_queues(q, true); } EXPORT_SYMBOL_GPL(blk_mq_unquiesce_queue); |