path: root/block/elevator.c
diff options
authorMing Lei <>2019-06-04 21:08:02 +0800
committerJens Axboe <>2019-06-06 22:39:39 -0600
commitc3e2219216c92919a6bd1711f340f5faa98695e6 (patch)
tree392cb3a4e9f9de822cd0ef9bfcfca787adcca366 /block/elevator.c
parentcf1db7fc8c2d31222701bd5c01b9cbaf89d8e7ce (diff)
block: free sched's request pool in blk_cleanup_queue
In theory, IO scheduler belongs to request queue, and the request pool of sched tags belongs to the request queue too. However, the current tags allocation interfaces are re-used for both driver tags and sched tags, and driver tags is definitely host wide, and doesn't belong to any request queue, same with its request pool. So we need tagset instance for freeing request of sched tags. Meantime, blk_mq_free_tag_set() often follows blk_cleanup_queue() in case of non-BLK_MQ_F_TAG_SHARED, this way requires that request pool of sched tags to be freed before calling blk_mq_free_tag_set(). Commit 47cdee29ef9d94e ("block: move blk_exit_queue into __blk_release_queue") moves blk_exit_queue into __blk_release_queue for simplying the fast path in generic_make_request(), then causes oops during freeing requests of sched tags in __blk_release_queue(). Fix the above issue by move freeing request pool of sched tags into blk_cleanup_queue(), this way is safe becasue queue has been frozen and no any in-queue requests at that time. Freeing sched tags has to be kept in queue's release handler becasue there might be un-completed dispatch activity which might refer to sched tags. Cc: Bart Van Assche <> Cc: Christoph Hellwig <> Fixes: 47cdee29ef9d94e485eb08f962c74943023a5271 ("block: move blk_exit_queue into __blk_release_queue") Tested-by: Yi Zhang <> Reported-by: kernel test robot <> Signed-off-by: Ming Lei <> Signed-off-by: Jens Axboe <>
Diffstat (limited to 'block/elevator.c')
1 files changed, 1 insertions, 1 deletions
diff --git a/block/elevator.c b/block/elevator.c
index ec55d5fc0b3e..2f17d66d0e61 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -178,7 +178,7 @@ static void elevator_release(struct kobject *kobj)
-void elevator_exit(struct request_queue *q, struct elevator_queue *e)
+void __elevator_exit(struct request_queue *q, struct elevator_queue *e)
if (e->type->ops.exit_sched)