[PATCH v2 32/51] btrfs: use bvec_get_last_page to get bio's last page

[Ming Lei <ming.lei@redhat.com>]

Preparing for supporting multipage bvec.

Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: David Sterba <dsterba@suse.com>
Cc: linux-btrfs@vger.kernel.org
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 fs/btrfs/compression.c | 5 ++++-
 fs/btrfs/extent_io.c   | 8 ++++++--
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 5972f74354ca..fdab5b821aa8 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -391,8 +391,11 @@ blk_status_t btrfs_submit_compressed_write(struct inode *inode, u64 start,
 static u64 bio_end_offset(struct bio *bio)
 {
 	struct bio_vec *last = &bio->bi_io_vec[bio->bi_vcnt - 1];
+	struct bio_vec bv;
 
-	return page_offset(last->bv_page) + last->bv_len + last->bv_offset;
+	bvec_get_last_page(last, &bv);
+
+	return page_offset(bv.bv_page) + bv.bv_len + bv.bv_offset;
 }
 
 static noinline int add_ra_bio_pages(struct inode *inode,
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 5b453cada1ea..7cc6c8a52e49 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2741,11 +2741,15 @@ static int __must_check submit_one_bio(struct bio *bio, int mirror_num,
 {
 	blk_status_t ret = 0;
 	struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
-	struct page *page = bvec->bv_page;
 	struct extent_io_tree *tree = bio->bi_private;
+	struct bio_vec bv;
+	struct page *page;
 	u64 start;
 
-	start = page_offset(page) + bvec->bv_offset;
+	bvec_get_last_page(bvec, &bv);
+	page = bv.bv_page;
+
+	start = page_offset(page) + bv.bv_offset;
 
 	bio->bi_private = NULL;
 	bio_get(bio);
-- 
2.9.4