tree 4a0929fa4e384718aabcc2180399b219f18f1615
parent 69e07c4adb8669fd77f3b59abdb436aca9f1bee9
author Ming Lei <ming.lei@redhat.com> 1496762528 +0800
committer Jens Axboe <axboe@kernel.dk> 1497817488 -0600

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>