block: rename and export rq_init()

This rename rq_init() blk_rq_init() and export it. Any path that hands
the request to the block layer needs to call it to initialize the
request.

This is a preparation for large command support, which needs to
initialize the request in a proper way (that is, just doing a memset()
will not work).
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

block/blk-barrier.c

@@ -143,7 +143,7 @@ static void queue_flush(struct request_queue *q, unsigned which)
 		end_io = post_flush_end_io;
 	}
 
-	rq_init(q, rq);
+	blk_rq_init(q, rq);
 	rq->cmd_flags = REQ_HARDBARRIER;
 	rq->rq_disk = q->bar_rq.rq_disk;
 	rq->end_io = end_io;
@@ -165,7 +165,7 @@ static inline struct request *start_ordered(struct request_queue *q,
 	blkdev_dequeue_request(rq);
 	q->orig_bar_rq = rq;
 	rq = &q->bar_rq;
-	rq_init(q, rq);
+	blk_rq_init(q, rq);
 	if (bio_data_dir(q->orig_bar_rq->bio) == WRITE)
 		rq->cmd_flags |= REQ_RW;
 	if (q->ordered & QUEUE_ORDERED_FUA)

block/blk-core.c

@@ -107,7 +107,7 @@ struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev)
 }
 EXPORT_SYMBOL(blk_get_backing_dev_info);
 
-void rq_init(struct request_queue *q, struct request *rq)
+void blk_rq_init(struct request_queue *q, struct request *rq)
 {
 	memset(rq, 0, sizeof(*rq));
 
@@ -120,6 +120,7 @@ void rq_init(struct request_queue *q, struct request *rq)
 	rq->tag = -1;
 	rq->ref_count = 1;
 }
+EXPORT_SYMBOL(blk_rq_init);
 
 static void req_bio_endio(struct request *rq, struct bio *bio,
 			  unsigned int nbytes, int error)
@@ -598,7 +599,7 @@ blk_alloc_request(struct request_queue *q, int rw, int priv, gfp_t gfp_mask)
 	if (!rq)
 		return NULL;
 
-	rq_init(q, rq);
+	blk_rq_init(q, rq);
 
 	/*
 	 * first three bits are identical in rq->cmd_flags and bio->bi_rw,

block/blk.h

@@ -10,7 +10,6 @@
 extern struct kmem_cache *blk_requestq_cachep;
 extern struct kobj_type blk_queue_ktype;
 
-void rq_init(struct request_queue *q, struct request *rq);
 void init_request_from_bio(struct request *req, struct bio *bio);
 void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
 			struct bio *bio);

include/linux/blkdev.h

@@ -607,6 +607,7 @@ extern int blk_register_queue(struct gendisk *disk);
 extern void blk_unregister_queue(struct gendisk *disk);
 extern void register_disk(struct gendisk *dev);
 extern void generic_make_request(struct bio *bio);
+extern void blk_rq_init(struct request_queue *q, struct request *rq);
 extern void blk_put_request(struct request *);
 extern void __blk_put_request(struct request_queue *, struct request *);
 extern void blk_end_sync_rq(struct request *rq, int error);