Re: [PATCH V10 07/19] btrfs: use bvec_last_segment to get bio's last page

Omar Sandoval
2018-11-16T00:22:04Z

On Thu, Nov 15, 2018 at 04:52:54PM +0800, Ming Lei wrote:
> Preparing for supporting multi-page bvec.
>
> Cc: Dave Chinner <dchinner@redhat.com>
> Cc: Kent Overstreet <kent.overstreet@gmail.com>
> Cc: Mike Snitzer <snitzer@redhat.com>
> Cc: dm-devel@redhat.com
> Cc: Alexander Viro <viro@zeniv.linux.org.uk>
> Cc: linux-fsdevel@vger.kernel.org
> Cc: Shaohua Li <shli@kernel.org>
> Cc: linux-raid@vger.kernel.org
> Cc: linux-erofs@lists.ozlabs.org
> Cc: David Sterba <dsterba@suse.com>
> Cc: linux-btrfs@vger.kernel.org
> Cc: Darrick J. Wong <darrick.wong@oracle.com>
> Cc: linux-xfs@vger.kernel.org
> Cc: Gao Xiang <gaoxiang25@huawei.com>
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: Theodore Ts'o <tytso@mit.edu>
> Cc: linux-ext4@vger.kernel.org
> Cc: Coly Li <colyli@suse.de>
> Cc: linux-bcache@vger.kernel.org
> Cc: Boaz Harrosh <ooo@electrozaur.com>
> Cc: Bob Peterson <rpeterso@redhat.com>
> Cc: cluster-devel@redhat.com

Reviewed-by: Omar Sandoval <osandov@fb.com>

> Signed-off-by: Ming Lei <ming.lei@redhat.com>
> ---
> fs/btrfs/compression.c | 5 ++++-
> fs/btrfs/extent_io.c | 5 +++--
> 2 files changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
> index 2955a4ea2fa8..161e14b8b180 100644
> --- a/fs/btrfs/compression.c
> +++ b/fs/btrfs/compression.c
> @@ -400,8 +400,11 @@ 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_last_bvec_all(bio);
> + struct bio_vec bv;
>
> - return page_offset(last->bv_page) + last->bv_len + last->bv_offset;
> + bvec_last_segment(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 d228f706ff3e..5d5965297e7e 100644
> --- a/fs/btrfs/extent_io.c
> +++ b/fs/btrfs/extent_io.c
> @@ -2720,11 +2720,12 @@ static int __must_check submit_one_bio(struct bio *bio, int mirror_num,
> {
> blk_status_t ret = 0;
> struct bio_vec *bvec = bio_last_bvec_all(bio);
> - struct page *page = bvec->bv_page;
> + struct bio_vec bv;
> struct extent_io_tree *tree = bio->bi_private;
> u64 start;
>
> - start = page_offset(page) + bvec->bv_offset;
> + bvec_last_segment(bvec, &bv);
> + start = page_offset(bv.bv_page) + bv.bv_offset;
>
> bio->bi_private = NULL;
>
> --
> 2.9.5
>