6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Bart Van Assche <bvanassche@xxxxxxx>
commit ccd9e252c515ac5a3ed04a414c95d1307d17f159 upstream.
Make sure that the tag_list_lock mutex is not held any longer than
necessary. This change reduces latency if e.g. blk_mq_quiesce_tagset()
is called concurrently from more than one thread. This function is used
by the NVMe core and also by the UFS driver.
Reported-by: Peter Wang <peter.wang@xxxxxxxxxxxx>
Cc: Chao Leng <lengchao@xxxxxxxxxx>
Cc: Ming Lei <ming.lei@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 414dd48e882c ("blk-mq: add tagset quiesce interface")
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
Reviewed-by: Keith Busch <kbusch@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20241022181617.2716173-1-bvanassche@xxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
block/blk-mq.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -283,8 +283,9 @@ void blk_mq_quiesce_tagset(struct blk_mq
if (!blk_queue_skip_tagset_quiesce(q))
blk_mq_quiesce_queue_nowait(q);
}
- blk_mq_wait_quiesce_done(set);
mutex_unlock(&set->tag_list_lock);
+
+ blk_mq_wait_quiesce_done(set);
}
EXPORT_SYMBOL_GPL(blk_mq_quiesce_tagset);
