block: Add bio_end_sector()

Just a little convenience macro - main reason to add it now is preparing
for immutable bio vecs, it'll reduce the size of the patch that puts
bi_sector/bi_size/bi_idx into a struct bvec_iter.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: Lars Ellenberg <drbd-dev@lists.linbit.com>
CC: Jiri Kosina <jkosina@suse.cz>
CC: Alasdair Kergon <agk@redhat.com>
CC: dm-devel@redhat.com
CC: Neil Brown <neilb@suse.de>
CC: Martin Schwidefsky <schwidefsky@de.ibm.com>
CC: Heiko Carstens <heiko.carstens@de.ibm.com>
CC: linux-s390@vger.kernel.org
CC: Chris Mason <chris.mason@fusionio.com>
CC: Steven Whitehouse <swhiteho@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 1 insertions, 2 deletions

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index f173c5af6461..bed072aa461f 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2527,8 +2527,7 @@ static int submit_extent_page(int rw, struct extent_io_tree *tree,
                 if (old_compressed)
                         contig = bio->bi_sector == sector;
                 else
-                        contig = bio->bi_sector + (bio->bi_size >> 9) ==
-                                sector;
+                        contig = bio_end_sector(bio) == sector;
 
                 if (prev_bio_flags != bio_flags || !contig ||
                     merge_bio(rw, tree, page, offset, page_size, bio, bio_flags) ||