On Mon, Nov 26, 2018 at 10:17:02AM +0800, Ming Lei wrote:
> From: Christoph Hellwig <hch@xxxxxx>
>
> bio_readpage_error currently uses bi_vcnt to decide if it is worth
> retrying an I/O. But the vector count is mostly an implementation
> artifact - it really should figure out if there is more than a
> single sector worth retrying. Use bi_size for that and shift by
> PAGE_SHIFT. This really should be blocks/sectors, but given that
> btrfs doesn't support a sector size different from the PAGE_SIZE
> using the page size keeps the changes to a minimum.
>
> Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Reviewed-by: Omar Sandoval <osandov@xxxxxx>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
> fs/btrfs/extent_io.c | 2 +-
> include/linux/bio.h | 6 ------
> 2 files changed, 1 insertion(+), 7 deletions(-)
>
> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
> index 15fd46582bb2..40751e86a2a9 100644
> --- a/fs/btrfs/extent_io.c
> +++ b/fs/btrfs/extent_io.c
> @@ -2368,7 +2368,7 @@ static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset,
> int read_mode = 0;
> blk_status_t status;
> int ret;
> - unsigned failed_bio_pages = bio_pages_all(failed_bio);
> + unsigned failed_bio_pages = failed_bio->bi_iter.bi_size >> PAGE_SHIFT;
>
> BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
>
> diff --git a/include/linux/bio.h b/include/linux/bio.h
> index 056fb627edb3..6f6bc331a5d1 100644
> --- a/include/linux/bio.h
> +++ b/include/linux/bio.h
> @@ -263,12 +263,6 @@ static inline void bio_get_last_bvec(struct bio *bio, struct bio_vec *bv)
> bv->bv_len = iter.bi_bvec_done;
> }
>
> -static inline unsigned bio_pages_all(struct bio *bio)
> -{
> - WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
> - return bio->bi_vcnt;
> -}
> -
> static inline struct bio_vec *bio_first_bvec_all(struct bio *bio)
> {
> WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
> --
> 2.9.5
>
