From: Yu Kuai <yukuai3@xxxxxxxxxx> In the case user trigger tags grow by queue sysfs attribute nr_requests, hctx->sched_tags will be freed directly and replaced with a new allocated tags, see blk_mq_tag_update_depth(). The problem is that hctx->sched_tags is from elevator->et->tags, while et->tags is still the freed tags, hence later elevator exit will try to free the tags again, causing kernel panic. Fix this problem by replacing et->tags with new allocated tags as well. Noted there are still some long term problems that will require some refactor to be fixed thoroughly[1]. [1] https://lore.kernel.org/all/20250815080216.410665-1-yukuai1@xxxxxxxxxxxxxxx/ Fixes: f5a6604f7a44 ("block: fix lockdep warning caused by lock dependency in elv_iosched_store") Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx> Reviewed-by: Ming Lei <ming.lei@xxxxxxxxxx> Reviewed-by: Nilay Shroff<nilay@xxxxxxxxxxxxx> --- block/blk-mq-tag.c | 1 + 1 file changed, 1 insertion(+) diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index d880c50629d6..5cffa5668d0c 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -622,6 +622,7 @@ int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx, return -ENOMEM; blk_mq_free_map_and_rqs(set, *tagsptr, hctx->queue_num); + hctx->queue->elevator->et->tags[hctx->queue_num] = new; *tagsptr = new; } else { /* -- 2.39.2
