From 852ec80983d682dc08a0573d37eeaa9814c4f6b1 Mon Sep 17 00:00:00 2001
From: Bart Van Assche <bart.vanassche@wdc.com>
Date: Wed, 21 Jun 2017 10:55:47 -0700
Subject: [PATCH] blk-mq: Make it safe to quiesce and unquiesce from an
interrupt handler
Git-commit: 852ec80983d682dc08a0573d37eeaa9814c4f6b1
Patch-mainline: v4.13-rc1
References: fate#322738,fate#322919,fate#322950,fate#323773
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 <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: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Coly Li <colyli@suse.de>
---
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