[PATCH v1 52/54] btrfs: use bvec_get_last_sp to get the last singlepage bvec

[Ming Lei <tom.leiming@gmail.com>]

Preparing for supporting multipage bvec.

Signed-off-by: Ming Lei <tom.leiming@gmail.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 adcf5568f010..485a60923bba 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -448,8 +448,11 @@ int 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 uninitialized_var(bv);
 
-	return page_offset(last->bv_page) + last->bv_len + last->bv_offset;
+	bvec_get_last_sp(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 3c021f4dd8bf..4a1c81cee883 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2733,11 +2733,15 @@ static int __must_check submit_one_bio(struct bio *bio, int mirror_num,
 {
 	int 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 uninitialized_var(bv);
+	struct page *page;
 	u64 start;
 
-	start = page_offset(page) + bvec->bv_offset;
+	bvec_get_last_sp(bvec, &bv);
+	page = bv.bv_page;
+
+	start = page_offset(page) + bv.bv_offset;
 
 	bio->bi_private = NULL;
 	bio_get(bio);
-- 
2.7.4