block: remove bio_clone() and all references.

bio_clone() is no longer used.
Only bio_clone_bioset() or bio_clone_fast().
This is for the best, as bio_clone() used fs_bio_set,
and filesystems are unlikely to want to use bio_clone().

So remove bio_clone() and all references.
This includes a fix to some incorrect documentation.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Documentation/block/biodoc.txt

@@ -632,7 +632,7 @@ to i/o submission, if the bio fields are likely to be accessed after the
 i/o is issued (since the bio may otherwise get freed in case i/o completion
 happens in the meantime).
 
-The bio_clone() routine may be used to duplicate a bio, where the clone
+The bio_clone_fast() routine may be used to duplicate a bio, where the clone
 shares the bio_vec_list with the original bio (i.e. both point to the
 same bio_vec_list). This would typically be used for splitting i/o requests
 in lvm or md.

block/bio.c

@@ -547,7 +547,7 @@ EXPORT_SYMBOL(zero_fill_bio);
  *
  * Description:
  *   Put a reference to a &struct bio, either one you have gotten with
- *   bio_alloc, bio_get or bio_clone. The last put of a bio will free it.
+ *   bio_alloc, bio_get or bio_clone_*. The last put of a bio will free it.
  **/
 void bio_put(struct bio *bio)
 {

block/blk-merge.c

@@ -115,13 +115,13 @@ static struct bio *blk_bio_segment_split(struct request_queue *q,
 		 * With arbitrary bio size, the incoming bio may be very
 		 * big. We have to split the bio into small bios so that
 		 * each holds at most BIO_MAX_PAGES bvecs because
-		 * bio_clone() can fail to allocate big bvecs.
+		 * bio_clone_bioset() can fail to allocate big bvecs.
 		 *
-		 * Those drivers which will need to use bio_clone()
+		 * Those drivers which will need to use bio_clone_bioset()
 		 * should tell us in some way.  For now, impose the
 		 * BIO_MAX_PAGES limit on all queues.
 		 *
-		 * TODO: handle users of bio_clone() differently.
+		 * TODO: handle users of bio_clone_bioset() differently.
 		 */
 		if (bvecs++ >= BIO_MAX_PAGES)
 			goto split;

drivers/md/md.c

@@ -185,7 +185,7 @@ static int start_readonly;
 static bool create_on_open = true;
 
 /* bio_clone_mddev
- * like bio_clone, but with a local bio set
+ * like bio_clone_bioset, but with a local bio set
  */
 
 struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs,

include/linux/bio.h

@@ -395,11 +395,6 @@ static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
 	return bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set);
 }
 
-static inline struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask)
-{
-	return bio_clone_bioset(bio, gfp_mask, fs_bio_set);
-}
-
 static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
 {
 	return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);