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

From: Ming Lei
Date: Mon Jun 26 2017 - 08:26:18 EST


Preparing for supporting multipage bvec.

Cc: Chris Mason <clm@xxxxxx>
Cc: Josef Bacik <jbacik@xxxxxx>
Cc: David Sterba <dsterba@xxxxxxxx>
Cc: linux-btrfs@xxxxxxxxxxxxxxx
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
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