blk-mq: Don't clear driver tags own mapping

Function blk_mq_clear_rq_mapping() is required to clear the sched tags
mappings in driver tags rqs[].

But there is no need for a driver tags to clear its own mapping, so skip
clearing the mapping in this scenario.

Signed-off-by: John Garry <john.garry@huawei.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/1633429419-228500-9-git-send-email-john.garry@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 0619298..38cffe3 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2317,6 +2317,10 @@ static void blk_mq_clear_rq_mapping(struct blk_mq_tags *drv_tags,
        struct page *page;
        unsigned long flags;
 
+       /* There is no need to clear a driver tags own mapping */
+       if (drv_tags == tags)
+               return;
+
        list_for_each_entry(page, &tags->page_list, lru) {
                unsigned long start = (unsigned long)page_address(page);
                unsigned long end = start + order_to_size(page->private);