md: Convert md_trim_bio() to use bio_advance()

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: NeilBrown <neilb@suse.de>
Acked-by: NeilBrown <neilb@suse.de>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index fcb878f..d323676 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -194,21 +194,12 @@ void md_trim_bio(struct bio *bio, int offset, int size)
        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;
-       }
+       bio_advance(bio, offset << 9);
+
+       bio->bi_size = size;
+
        /* 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,