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| author | Ming Lei <ming.lei@redhat.com> | 2021-11-11 09:51:33 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-11-11 19:52:33 +0100 |
| commit | 10f7335e3627b4efa341ef8ac457f2c0770c5c19 (patch) | |
| tree | 0f53e8e80279c25b7992bae4d94d93004fa15980 /block/blk-mq-sched.c | |
| parent | block: fix kerneldoc for disk_register_independent_access__ranges() (diff) | |
| download | linux-10f7335e3627b4efa341ef8ac457f2c0770c5c19.tar.xz linux-10f7335e3627b4efa341ef8ac457f2c0770c5c19.zip | |
blk-mq: don't grab ->q_usage_counter in blk_mq_sched_bio_merge
blk_mq_sched_bio_merge is only called from blk-mq.c:blk_attempt_bio_merge(),
which is called when queue usage counter is grabbed already:
1) blk_mq_get_new_requests()
2) blk_mq_get_request()
- cached request in current plug owns one queue usage counter
So don't grab ->q_usage_counter in blk_mq_sched_bio_merge(), and more
importantly this nest way causes hang in blk_mq_freeze_queue_wait().
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211111085134.345235-2-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-mq-sched.c')
| -rw-r--r-- | block/blk-mq-sched.c | 4 |
1 files changed, 0 insertions, 4 deletions
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index 4be652fa38e7..ba21449439cc 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -370,9 +370,6 @@ bool blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio, bool ret = false; enum hctx_type type; - if (bio_queue_enter(bio)) - return false; - if (e && e->type->ops.bio_merge) { ret = e->type->ops.bio_merge(q, bio, nr_segs); goto out_put; @@ -397,7 +394,6 @@ bool blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio, spin_unlock(&ctx->lock); out_put: - blk_queue_exit(q); return ret; } |