block: simplify and export blk_rq_append_bio

The target SCSI passthrough backend is much better served with the low-level
blk_rq_append_bio construct then the helpers built on top of it, so export it.

Also use the opportunity to remove the pointless request_queue argument and
make the code flow a little more readable.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/block/blk-core.c b/block/blk-core.c
index 4d8794925fe94d029d1c6a10258ca134e2f3c55c..a2230186c36dacfd19b10529e8742379a2ec8e4d 100644 (file)
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1363,7 +1363,7 @@ struct request *blk_make_request(struct request_queue *q, struct bio *bio,
                int ret;
 
                blk_queue_bounce(q, &bounce_bio);
-               ret = blk_rq_append_bio(q, rq, bounce_bio);
+               ret = blk_rq_append_bio(rq, bounce_bio);
                if (unlikely(ret)) {
                        blk_put_request(rq);
                        return ERR_PTR(ret);

diff --git a/block/blk-map.c b/block/blk-map.c
index 61733a660c3afcbf5ae5362bbe3b3df04f0a24de..b8657fa8dc9af7b2f5fe7958693df063cc4c9019 100644 (file)
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -9,21 +9,26 @@
 
 #include "blk.h"
 
-int blk_rq_append_bio(struct request_queue *q, struct request *rq,
-                     struct bio *bio)
+/*
+ * Append a bio to a passthrough request.  Only works can be merged into
+ * the request based on the driver constraints.
+ */
+int blk_rq_append_bio(struct request *rq, struct bio *bio)
 {
-       if (!rq->bio)
-               blk_rq_bio_prep(q, rq, bio);
-       else if (!ll_back_merge_fn(q, rq, bio))
-               return -EINVAL;
-       else {
+       if (!rq->bio) {
+               blk_rq_bio_prep(rq->q, rq, bio);
+       } else {
+               if (!ll_back_merge_fn(rq->q, rq, bio))
+                       return -EINVAL;
+
                rq->biotail->bi_next = bio;
                rq->biotail = bio;
-
                rq->__data_len += bio->bi_iter.bi_size;
        }
+
        return 0;
 }
+EXPORT_SYMBOL(blk_rq_append_bio);
 
 static int __blk_rq_unmap_user(struct bio *bio)
 {
@@ -71,7 +76,7 @@ static int __blk_rq_map_user_iov(struct request *rq,
         */
        bio_get(bio);
 
-       ret = blk_rq_append_bio(q, rq, bio);
+       ret = blk_rq_append_bio(rq, bio);
        if (ret) {
                bio_endio(bio);
                __blk_rq_unmap_user(orig_bio);
@@ -229,7 +234,7 @@ int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
        if (do_copy)
                rq->cmd_flags |= REQ_COPY_USER;
 
-       ret = blk_rq_append_bio(q, rq, bio);
+       ret = blk_rq_append_bio(rq, bio);
        if (unlikely(ret)) {
                /* request is too big */
                bio_put(bio);

diff --git a/block/blk.h b/block/blk.h
index 70e4aee9cdcb6ead5974dce6a5abf454344b5b24..c37492f5edaaece9c7603a6844872c3f279cefb0 100644 (file)
--- a/block/blk.h
+++ b/block/blk.h
@@ -64,8 +64,6 @@ void blk_exit_rl(struct request_list *rl);
 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);
-int blk_rq_append_bio(struct request_queue *q, struct request *rq,
-                     struct bio *bio);
 void blk_queue_bypass_start(struct request_queue *q);
 void blk_queue_bypass_end(struct request_queue *q);
 void blk_dequeue_request(struct request *rq);

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 156455cb07ad00f68b66af4c5e5f7cd1222597ed..706c8bf61c84a21a970a34da98b2e848ff516a58 100644 (file)
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -802,6 +802,7 @@ extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
 extern void blk_rq_unprep_clone(struct request *rq);
 extern int blk_insert_cloned_request(struct request_queue *q,
                                     struct request *rq);
+extern int blk_rq_append_bio(struct request *rq, struct bio *bio);
 extern void blk_delay_queue(struct request_queue *, unsigned long);
 extern void blk_queue_split(struct request_queue *, struct bio **,
                            struct bio_set *);