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| author | Ming Lei <ming.lei@redhat.com> | 2019-09-26 06:23:54 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2019-09-26 00:45:05 -0600 |
| commit | 284b94be1925dbe035ce5218d8b5c197321262c7 (patch) | |
| tree | cf92c78c0064fa7b31b0d03baf266a18ed21f5e7 /block | |
| parent | f41def397161053eb0d3ed6861ef65985efbf293 (diff) | |
| download | lwn-284b94be1925dbe035ce5218d8b5c197321262c7.tar.gz lwn-284b94be1925dbe035ce5218d8b5c197321262c7.zip | |
blk-mq: move lockdep_assert_held() into elevator_exit
Commit c48dac137a62 ("block: don't hold q->sysfs_lock in elevator_init_mq")
removes q->sysfs_lock from elevator_init_mq(), but forgot to deal with
lockdep_assert_held() called in blk_mq_sched_free_requests() which is
run in failure path of elevator_init_mq().
blk_mq_sched_free_requests() is called in the following 3 functions:
elevator_init_mq()
elevator_exit()
blk_cleanup_queue()
In blk_cleanup_queue(), blk_mq_sched_free_requests() is followed exactly
by 'mutex_lock(&q->sysfs_lock)'.
So moving the lockdep_assert_held() from blk_mq_sched_free_requests()
into elevator_exit() for fixing the report by syzbot.
Reported-by: syzbot+da3b7677bb913dc1b737@syzkaller.appspotmail.com
Fixed: c48dac137a62 ("block: don't hold q->sysfs_lock in elevator_init_mq")
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-mq-sched.c | 2 | ||||
| -rw-r--r-- | block/blk.h | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index c9d183d6c499..ca22afd47b3d 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -555,8 +555,6 @@ void blk_mq_sched_free_requests(struct request_queue *q) struct blk_mq_hw_ctx *hctx; int i; - lockdep_assert_held(&q->sysfs_lock); - queue_for_each_hw_ctx(q, hctx, i) { if (hctx->sched_tags) blk_mq_free_rqs(q->tag_set, hctx->sched_tags, i); diff --git a/block/blk.h b/block/blk.h index ed347f7a97b1..25773d668ec0 100644 --- a/block/blk.h +++ b/block/blk.h @@ -194,6 +194,8 @@ void elv_unregister_queue(struct request_queue *q); static inline void elevator_exit(struct request_queue *q, struct elevator_queue *e) { + lockdep_assert_held(&q->sysfs_lock); + blk_mq_sched_free_requests(q); __elevator_exit(q, e); } |