block: Consolidate duplicated bio_trim() implementations

Someone cut and pasted md's md_trim_bio() into xen-blkfront.c. Come on,
we should know better than this.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Neil Brown <neilb@suse.de>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 1 insertions, 52 deletions

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index a4660bbee8a6..8d53ed293606 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -1336,57 +1336,6 @@ static int blkfront_probe(struct xenbus_device *dev,
 	return 0;
 }
 
-/*
- * This is a clone of md_trim_bio, used to split a bio into smaller ones
- */
-static void trim_bio(struct bio *bio, int offset, int size)
-{
-	/* 'bio' is a cloned bio which we need to trim to match
-	 * the given offset and size.
-	 * This requires adjusting bi_sector, bi_size, and bi_io_vec
-	 */
-	int i;
-	struct bio_vec *bvec;
-	int sofar = 0;
-
-	size <<= 9;
-	if (offset == 0 && size == bio->bi_size)
-		return;
-
-	bio->bi_sector += offset;
-	bio->bi_size = size;
-	offset <<= 9;
-	clear_bit(BIO_SEG_VALID, &bio->bi_flags);
-
-	while (bio->bi_idx < bio->bi_vcnt &&
-	       bio->bi_io_vec[bio->bi_idx].bv_len <= offset) {
-		/* remove this whole bio_vec */
-		offset -= bio->bi_io_vec[bio->bi_idx].bv_len;
-		bio->bi_idx++;
-	}
-	if (bio->bi_idx < bio->bi_vcnt) {
-		bio->bi_io_vec[bio->bi_idx].bv_offset += offset;
-		bio->bi_io_vec[bio->bi_idx].bv_len -= offset;
-	}
-	/* avoid any complications with bi_idx being non-zero*/
-	if (bio->bi_idx) {
-		memmove(bio->bi_io_vec, bio->bi_io_vec+bio->bi_idx,
-			(bio->bi_vcnt - bio->bi_idx) * sizeof(struct bio_vec));
-		bio->bi_vcnt -= bio->bi_idx;
-		bio->bi_idx = 0;
-	}
-	/* Make sure vcnt and last bv are not too big */
-	bio_for_each_segment(bvec, bio, i) {
-		if (sofar + bvec->bv_len > size)
-			bvec->bv_len = size - sofar;
-		if (bvec->bv_len == 0) {
-			bio->bi_vcnt = i;
-			break;
-		}
-		sofar += bvec->bv_len;
-	}
-}
-
 static void split_bio_end(struct bio *bio, int error)
 {
 	struct split_bio *split_bio = bio->bi_private;
@@ -1522,7 +1471,7 @@ static int blkif_recover(struct blkfront_info *info)
 					   (unsigned int)(bio->bi_size >> 9) - offset);
 				cloned_bio = bio_clone(bio, GFP_NOIO);
 				BUG_ON(cloned_bio == NULL);
-				trim_bio(cloned_bio, offset, size);
+				bio_trim(cloned_bio, offset, size);
 				cloned_bio->bi_private = split_bio;
 				cloned_bio->bi_end_io = split_bio_end;
 				submit_bio(cloned_bio->bi_rw, cloned_bio);