diff options
| author | Ming Lei <minlei@redhat.com> | 2017-08-02 08:01:45 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2017-08-02 08:23:57 -0600 |
| commit | 1ad43c0078b79a76accd0fe64062e47b3430dc6b (patch) | |
| tree | 480939827df51b046781e8d2f16def36f6412e0c /block | |
| parent | 46d556e6aaa0ec4dc83648ab1ca3d01dd2fa3ea3 (diff) | |
| download | lwn-1ad43c0078b79a76accd0fe64062e47b3430dc6b.tar.gz lwn-1ad43c0078b79a76accd0fe64062e47b3430dc6b.zip | |
blk-mq: don't leak preempt counter/q_usage_counter when allocating rq failed
When blk_mq_get_request() failed, preempt counter isn't
released, and blk_mq_make_request() doesn't release the counter
too.
This patch fixes the issue, and makes sure that preempt counter
is only held if rq is allocated successfully. The same policy is
applied on .q_usage_counter too.
Signed-off-by: Ming Lei <minlei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-mq.c | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c index 041f7b7fa0d6..211ef367345f 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -301,11 +301,12 @@ static struct request *blk_mq_get_request(struct request_queue *q, struct elevator_queue *e = q->elevator; struct request *rq; unsigned int tag; + struct blk_mq_ctx *local_ctx = NULL; blk_queue_enter_live(q); data->q = q; if (likely(!data->ctx)) - data->ctx = blk_mq_get_ctx(q); + data->ctx = local_ctx = blk_mq_get_ctx(q); if (likely(!data->hctx)) data->hctx = blk_mq_map_queue(q, data->ctx->cpu); if (op & REQ_NOWAIT) @@ -324,6 +325,10 @@ static struct request *blk_mq_get_request(struct request_queue *q, tag = blk_mq_get_tag(data); if (tag == BLK_MQ_TAG_FAIL) { + if (local_ctx) { + blk_mq_put_ctx(local_ctx); + data->ctx = NULL; + } blk_queue_exit(q); return NULL; } @@ -356,12 +361,12 @@ struct request *blk_mq_alloc_request(struct request_queue *q, unsigned int op, rq = blk_mq_get_request(q, NULL, op, &alloc_data); - blk_mq_put_ctx(alloc_data.ctx); - blk_queue_exit(q); - if (!rq) return ERR_PTR(-EWOULDBLOCK); + blk_mq_put_ctx(alloc_data.ctx); + blk_queue_exit(q); + rq->__data_len = 0; rq->__sector = (sector_t) -1; rq->bio = rq->biotail = NULL; @@ -407,11 +412,11 @@ struct request *blk_mq_alloc_request_hctx(struct request_queue *q, rq = blk_mq_get_request(q, NULL, op, &alloc_data); - blk_queue_exit(q); - if (!rq) return ERR_PTR(-EWOULDBLOCK); + blk_queue_exit(q); + return rq; } EXPORT_SYMBOL_GPL(blk_mq_alloc_request_hctx); |