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

[Omar Sandoval]

On Thu, Nov 15, 2018 at 04:52:54PM +0800, Ming Lei wrote:
> Preparing for supporting multi-page bvec.
> 
> Cc: Dave Chinner <dchinner@xxxxxxxxxx>
> Cc: Kent Overstreet <kent.overstreet@xxxxxxxxx>
> Cc: Mike Snitzer <snitzer@xxxxxxxxxx>
> Cc: dm-devel@xxxxxxxxxx
> Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
> Cc: linux-fsdevel@xxxxxxxxxxxxxxx
> Cc: Shaohua Li <shli@xxxxxxxxxx>
> Cc: linux-raid@xxxxxxxxxxxxxxx
> Cc: linux-erofs@xxxxxxxxxxxxxxxx
> Cc: David Sterba <dsterba@xxxxxxxx>
> Cc: linux-btrfs@xxxxxxxxxxxxxxx
> Cc: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> Cc: linux-xfs@xxxxxxxxxxxxxxx
> Cc: Gao Xiang <gaoxiang25@xxxxxxxxxx>
> Cc: Christoph Hellwig <hch@xxxxxx>
> Cc: Theodore Ts'o <tytso@xxxxxxx>
> Cc: linux-ext4@xxxxxxxxxxxxxxx
> Cc: Coly Li <colyli@xxxxxxx>
> Cc: linux-bcache@xxxxxxxxxxxxxxx
> Cc: Boaz Harrosh <ooo@xxxxxxxxxxxxxxx>
> Cc: Bob Peterson <rpeterso@xxxxxxxxxx>
> Cc: cluster-devel@xxxxxxxxxx

Reviewed-by: Omar Sandoval <osandov@xxxxxx>

> Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
> ---
>  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
>