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authorMing Lei <ming.lei@redhat.com>2019-06-04 15:08:02 +0200
committerJens Axboe <axboe@kernel.dk>2019-06-07 06:39:39 +0200
commitc3e2219216c92919a6bd1711f340f5faa98695e6 (patch)
tree392cb3a4e9f9de822cd0ef9bfcfca787adcca366 /block/blk-mq-sched.h
parentmmc: also set max_segment_size in the device (diff)
downloadlinux-c3e2219216c92919a6bd1711f340f5faa98695e6.tar.xz
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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 <bvanassche@acm.org> Cc: Christoph Hellwig <hch@lst.de> Fixes: 47cdee29ef9d94e485eb08f962c74943023a5271 ("block: move blk_exit_queue into __blk_release_queue") Tested-by: Yi Zhang <yi.zhang@redhat.com> Reported-by: kernel test robot <rong.a.chen@intel.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-mq-sched.h')
-rw-r--r--block/blk-mq-sched.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/block/blk-mq-sched.h b/block/blk-mq-sched.h
index c7bdb52367ac..3cf92cbbd8ac 100644
--- a/block/blk-mq-sched.h
+++ b/block/blk-mq-sched.h
@@ -28,6 +28,7 @@ void blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx);
int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e);
void blk_mq_exit_sched(struct request_queue *q, struct elevator_queue *e);
+void blk_mq_sched_free_requests(struct request_queue *q);
static inline bool
blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio)