[PATCH v4 07/12] block: Add a comment above queue_lockdep_assert_held()
From: Bart Van Assche <hidden>
Date: 2017-06-19 22:07:56
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
From: Bart Van Assche <redacted> Add a comment above the queue_lockdep_assert_held() macro that explains the purpose of the q->queue_lock test. Signed-off-by: Bart Van Assche <redacted> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.com> Cc: Omar Sandoval <redacted> Cc: Ming Lei <redacted> --- include/linux/blkdev.h | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index ff0ae83235ea..c00a6b99e77c 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h@@ -635,6 +635,13 @@ struct request_queue { (1 << QUEUE_FLAG_SAME_COMP) | \ (1 << QUEUE_FLAG_POLL)) +/* + * @q->queue_lock is set while a queue is being initialized. Since we know + * that no other threads access the queue object before @q->queue_lock has + * been set, it is safe to manipulate queue flags without holding the + * queue_lock if @q->queue_lock == NULL. See also blk_alloc_queue_node() and + * blk_init_allocated_queue(). + */ static inline void queue_lockdep_assert_held(struct request_queue *q) { if (q->queue_lock)
--
2.13.1