blk-mq: handle already freed tags gracefully in blk_mq_free_rqs

To simplify further changes allow for double calling blk_mq_free_rqs on
a queue.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
[hch: split out from a larger patch]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20220308055200.735835-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 40f634ab7026620faa09ee94c58b67ce344b2b0e..f7ef8e2ab935b7f972e44050e36f630906a372de 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -3071,6 +3071,9 @@ void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
        struct blk_mq_tags *drv_tags;
        struct page *page;
 
+       if (list_empty(&tags->page_list))
+               return;
+
        if (blk_mq_is_shared_tags(set->flags))
                drv_tags = set->shared_tags;
        else