6.6-stable review patch. If anyone has any objections, please let me know.
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From: Bart Van Assche bvanassche@acm.org
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@mediatek.com Cc: Chao Leng lengchao@huawei.com Cc: Ming Lei ming.lei@redhat.com Cc: stable@vger.kernel.org Fixes: 414dd48e882c ("blk-mq: add tagset quiesce interface") Signed-off-by: Bart Van Assche bvanassche@acm.org Reviewed-by: Keith Busch kbusch@kernel.org Link: https://lore.kernel.org/r/20241022181617.2716173-1-bvanassche@acm.org Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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);