From 7dfdbc7367f6f789715cab2cb484b78ab45e9f3e Mon Sep 17 00:00:00 2001
From: Bart Van Assche <bart.vanassche@wdc.com>
Date: Wed, 7 Mar 2018 17:10:05 -0800
Subject: block: Protect queue flag changes with the queue lock

Since the queue flags may be changed concurrently from multiple
contexts after a queue becomes visible in sysfs, make these changes
safe by protecting these with the queue lock.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 block/blk-mq.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'block/blk-mq.c')

diff --git a/block/blk-mq.c b/block/blk-mq.c
index a86899022683..f5c7dbcb954f 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2997,7 +2997,7 @@ EXPORT_SYMBOL_GPL(blk_mq_update_nr_hw_queues);
 static bool blk_poll_stats_enable(struct request_queue *q)
 {
 	if (test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags) ||
-	    test_and_set_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags))
+	    blk_queue_flag_test_and_set(QUEUE_FLAG_POLL_STATS, q))
 		return true;
 	blk_stat_add_callback(q, q->poll_cb);
 	return false;
-- 
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