[PATCH v4 03/12] block: Introduce request_queue.initialize_rq_fn()
From: Bart Van Assche <hidden>
Date: 2017-06-19 22:07:52
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
From: Bart Van Assche <redacted> Several block drivers need to initialize the driver-private request 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 new callback functions to struct request_queue and to struct blk_mq_ops. Signed-off-by: Bart Van Assche <redacted> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.com> Cc: Omar Sandoval <redacted> --- block/blk-core.c | 17 +++++++++++++++-- include/linux/blk-mq.h | 2 ++ include/linux/blkdev.h | 4 ++++ 3 files changed, 21 insertions(+), 2 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index 93edf22009fe..0c08cf3559c9 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c@@ -1366,12 +1366,25 @@ 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)) + goto out; + + if (q->mq_ops && q->mq_ops->initialize_rq_fn) + q->mq_ops->initialize_rq_fn(req); + else if (!q->mq_ops && q->initialize_rq_fn) + q->initialize_rq_fn(req); + +out: + return req; } EXPORT_SYMBOL(blk_get_request);
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 698015526ca7..23d32ff0b462 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h@@ -144,6 +144,8 @@ struct blk_mq_ops { init_request_fn *init_request; exit_request_fn *exit_request; reinit_request_fn *reinit_request; + /* Called from inside blk_get_request() */ + void (*initialize_rq_fn)(struct request *rq); map_queues_fn *map_queues;
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index c2844c27ef65..ff0ae83235ea 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;
--
2.13.1