dm-rq needs to free request which has been dispatched and not completed by underlying queue. However, the underlying queue may have allocated private data for this request in .queue_rq(), so the request private part is leaked.
Add one new callback of .cleanup_rq() to free the request private data. Another use case is to free request when the hctx is dead during cpu hotplug context. Cc: Ewan D. Milne <[email protected]> Cc: Bart Van Assche <[email protected]> Cc: Hannes Reinecke <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Mike Snitzer <[email protected]> Cc: [email protected] Cc: <[email protected]> Fixes: 396eaf21ee17 ("blk-mq: improve DM's blk-mq IO merging via blk_insert_cloned_request feedback") Signed-off-by: Ming Lei <[email protected]> --- block/blk-mq.c | 3 +++ include/linux/blk-mq.h | 7 +++++++ 2 files changed, 10 insertions(+) diff --git a/block/blk-mq.c b/block/blk-mq.c index b038ec680e84..fc38d95c557f 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -502,6 +502,9 @@ void blk_mq_free_request(struct request *rq) struct blk_mq_ctx *ctx = rq->mq_ctx; struct blk_mq_hw_ctx *hctx = rq->mq_hctx; + if (q->mq_ops->cleanup_rq) + q->mq_ops->cleanup_rq(rq); + if (rq->rq_flags & RQF_ELVPRIV) { if (e && e->type->ops.finish_request) e->type->ops.finish_request(rq); diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 3fa1fa59f9b2..5882675c1989 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -140,6 +140,7 @@ typedef int (poll_fn)(struct blk_mq_hw_ctx *); typedef int (map_queues_fn)(struct blk_mq_tag_set *set); typedef bool (busy_fn)(struct request_queue *); typedef void (complete_fn)(struct request *); +typedef void (cleanup_rq_fn)(struct request *); struct blk_mq_ops { @@ -200,6 +201,12 @@ struct blk_mq_ops { /* Called from inside blk_get_request() */ void (*initialize_rq_fn)(struct request *rq); + /* + * Called before freeing one request which isn't completed yet, + * and usually for freeing the driver private part + */ + cleanup_rq_fn *cleanup_rq; + /* * If set, returns whether or not this queue currently is busy */ -- 2.20.1 -- dm-devel mailing list [email protected] https://www.redhat.com/mailman/listinfo/dm-devel
