[PATCH 08/19] block: Introduce request_queue.initialize_rq_fn()
From: Bart Van Assche <hidden>
Date: 2017-05-25 18:43:16
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
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 <redacted> Reviewed-by: Hannes Reinecke <hare@suse.com> Cc: Jens Axboe <axboe@fb.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Omar Sandoval <redacted> Cc: linux-block@vger.kernel.org --- block/blk-core.c | 3 +++ block/blk-mq.c | 3 +++ include/linux/blkdev.h | 4 ++++ 3 files changed, 10 insertions(+)
diff --git a/block/blk-core.c b/block/blk-core.c
index 9416f6f495d4..fa453ed95973 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c@@ -126,6 +126,9 @@ void blk_rq_init(struct request_queue *q, struct request *rq) rq->start_time = jiffies; set_start_time_ns(rq); rq->part = NULL; + + if (q->initialize_rq_fn) + q->initialize_rq_fn(rq); } EXPORT_SYMBOL(blk_rq_init);
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 9ae1d9ccf4df..a1620b36b95c 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c@@ -241,6 +241,9 @@ void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx, rq->end_io_data = NULL; rq->next_rq = NULL; + if (q->initialize_rq_fn) + q->initialize_rq_fn(rq); + ctx->rq_dispatched[op_is_sync(op)]++; } EXPORT_SYMBOL_GPL(blk_mq_rq_ctx_init);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 94fd2600584d..8a223a0c95d5 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