[PATCH 3/3] blk-mq: Make it safe to quiesce and unquiesce from an interrupt handler
From: Bart Van Assche <hidden>
Date: 2017-06-21 17:55:47
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
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 f4560ffe8cec ("blk-mq: use QUEUE_FLAG_QUIESCED to quiesce queue")
Signed-off-by: Bart Van Assche <redacted>
Cc: Ming Lei <redacted>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
---
block/blk-mq.c | 20 ++++++++++++++++++--
include/linux/blk-mq.h | 10 +---------
2 files changed, 19 insertions(+), 11 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 1c4f1f4978c6..2caac30e128a 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c@@ -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);
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 366b83cee955..23d32ff0b462 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h@@ -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
--
2.13.1