Several block drivers need to initialize the driver-private data after having called blk_get_request() and before .prep_rq_fn() is called, e.g. when submitting a REQ_OP_SCSI_* request. Avoid that that initialization code has to be repeated after every blk_get_request() call by adding a new callback function to struct request_queue.
Signed-off-by: Bart Van Assche <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Hannes Reinecke <[email protected]> Cc: Omar Sandoval <[email protected]> --- block/blk-core.c | 11 +++++++++-- include/linux/blkdev.h | 4 ++++ 2 files changed, 13 insertions(+), 2 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 3bc431a77309..3f68bc1f044c 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1308,12 +1308,19 @@ static struct request *blk_old_get_request(struct request_queue *q, struct request *blk_get_request(struct request_queue *q, unsigned int op, gfp_t gfp_mask) { + struct request *req; + if (q->mq_ops) - return blk_mq_alloc_request(q, op, + req = blk_mq_alloc_request(q, op, (gfp_mask & __GFP_DIRECT_RECLAIM) ? 0 : BLK_MQ_REQ_NOWAIT); else - return blk_old_get_request(q, op, gfp_mask); + req = blk_old_get_request(q, op, gfp_mask); + + if (!IS_ERR(req) && q->initialize_rq_fn) + q->initialize_rq_fn(req); + + return req; } EXPORT_SYMBOL(blk_get_request); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 6c4235018b49..cbc0028290e4 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -410,8 +410,12 @@ struct request_queue { rq_timed_out_fn *rq_timed_out_fn; dma_drain_needed_fn *dma_drain_needed; lld_busy_fn *lld_busy_fn; + /* Called just after a request is allocated */ init_rq_fn *init_rq_fn; + /* Called just before a request is freed */ exit_rq_fn *exit_rq_fn; + /* Called from inside blk_get_request() */ + void (*initialize_rq_fn)(struct request *rq); const struct blk_mq_ops *mq_ops; -- 2.12.2
