Commit 852ec809 authored by Bart Van Assche's avatar Bart Van Assche Committed by Jens Axboe
Browse files

blk-mq: Make it safe to quiesce and unquiesce from an interrupt handler 



Since blk_mq_quiesce_queue_nowait() can be called from interrupt
context, make this safe. Since this function is not in the hot
path, uninline it.

Fixes: commit f4560ffe ("blk-mq: use QUEUE_FLAG_QUIESCED to quiesce queue")
Signed-off-by: default avatarBart Van Assche <bart.vanassche@wdc.com>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 34bd9c1c

block/blk-mq.c

+18 −2
Original line number Diff line number Diff line
@@ -153,6 +153,20 @@ void blk_mq_unfreeze_queue(struct request_queue *q) 
}

EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue);



/*

 * FIXME: replace the scsi_internal_device_*block_nowait() calls in the

 * mpt3sas driver such that this function can be removed.

 */

void blk_mq_quiesce_queue_nowait(struct request_queue *q)

{

	unsigned long flags;



	spin_lock_irqsave(q->queue_lock, flags);

	queue_flag_set(QUEUE_FLAG_QUIESCED, q);

	spin_unlock_irqrestore(q->queue_lock, flags);

}

EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue_nowait);



/**

 * blk_mq_quiesce_queue() - wait until all ongoing dispatches have finished

 * @q: request queue.
@@ -190,9 +204,11 @@ EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue); 
 */

void blk_mq_unquiesce_queue(struct request_queue *q)

{

	spin_lock_irq(q->queue_lock);

	unsigned long flags;



	spin_lock_irqsave(q->queue_lock, flags);

	queue_flag_clear(QUEUE_FLAG_QUIESCED, q);

	spin_unlock_irq(q->queue_lock);

	spin_unlock_irqrestore(q->queue_lock, flags);



	/* dispatch requests which are inserted during quiescing */

	blk_mq_run_hw_queues(q, true);

include/linux/blk-mq.h

+1 −9
Original line number Diff line number Diff line
@@ -266,15 +266,7 @@ int blk_mq_reinit_tagset(struct blk_mq_tag_set *set); 
int blk_mq_map_queues(struct blk_mq_tag_set *set);

void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues);



/*

 * FIXME: this helper is just for working around mpt3sas.

 */

static inline void blk_mq_quiesce_queue_nowait(struct request_queue *q)

{

	spin_lock_irq(q->queue_lock);

	queue_flag_set(QUEUE_FLAG_QUIESCED, q);

	spin_unlock_irq(q->queue_lock);

}

void blk_mq_quiesce_queue_nowait(struct request_queue *q);



/*

 * Driver command data is immediately after the request. So subtract request

CRA Git | Maintained and supported by SUSTech CRA and CCSE