Re: [PATCH 08/11] ntfs: submit one bio per compressed write unit

2026=EB=85=84 7=EC=9B=94 21=EC=9D=BC (=ED=99=94) =EC=98=A4=ED=9B=84 6:55, N=
amjae Jeon <[email protected]>=EB=8B=98=EC=9D=B4 =EC=9E=91=EC=84=B1:
>
> ntfs_write_cb() allocates a single-vector bio and synchronously submits i=
t
> whenever another output page cannot be added. A 64 KiB uncompressed unit
> therefore requires up to sixteen separate bio submissions.
>
> Allocate enough vectors for the complete unit, add all output pages, and
> perform one synchronous submission.
>
> Signed-off-by: Namjae Jeon <[email protected]>

Looks good to me.

Reviewed-by: Hyunchul Lee <[email protected]>


> ---
>  fs/ntfs/compress.c | 43 +++++++++++--------------------------------
>  1 file changed, 11 insertions(+), 32 deletions(-)
>
> diff --git a/fs/ntfs/compress.c b/fs/ntfs/compress.c
> index f3c14518f78e..a3af669b1008 100644
> --- a/fs/ntfs/compress.c
> +++ b/fs/ntfs/compress.c
> @@ -1327,7 +1327,7 @@ static int ntfs_write_cb(struct ntfs_inode *ni, lof=
f_t pos, struct page **pages,
>         static char twozeroes[] =3D {0x02, 0xb0, 0x00, 0x00, 0x00};
>         /* more compressed zeroes, to be followed by some count */
>         static char morezeroes[] =3D {0x03, 0xb0, 0x02, 0x00};
> -       s64 bio_lcn;
> +       s64 bio_lcn, bio_pos;
>         struct runlist_element *rlc, *rl;
>         int i, err;
>         u32 cb_clusters =3D ni->itype.compressed.block_clusters;
> @@ -1410,41 +1410,20 @@ static int ntfs_write_cb(struct ntfs_inode *ni, l=
off_t pos, struct page **pages,
>         }
>
>         bio_lcn =3D rlc->lcn;
> -       i =3D 0;
> -       while (bio_size > 0) {
> -               int page_size;
> -
> -               if (bio_size >=3D PAGE_SIZE) {
> -                       page_size =3D PAGE_SIZE;
> -                       bio_size -=3D PAGE_SIZE;
> -               } else {
> -                       page_size =3D bio_size;
> -                       bio_size =3D 0;
> -               }
> +       bio_pos =3D ntfs_cluster_to_bytes(vol, bio_lcn);
> +       bio =3D bio_alloc(vol->sb->s_bdev, DIV_ROUND_UP(bio_size, PAGE_SI=
ZE),
> +                       REQ_OP_WRITE, GFP_NOIO);
> +       bio->bi_iter.bi_sector =3D ntfs_bytes_to_sector(vol, bio_pos);
>
> -setup_bio:
> -               if (!bio) {
> -                       bio =3D bio_alloc(vol->sb->s_bdev, 1, REQ_OP_WRIT=
E,
> -                                       GFP_NOIO);
> -                       if (!bio) {
> -                               err =3D -ENOMEM;
> -                               goto free_rlc;
> -                       }
> -                       bio->bi_iter.bi_sector =3D
> -                               ntfs_bytes_to_sector(vol,
> -                                               ntfs_cluster_to_bytes(vol=
, bio_lcn) +
> -                                               ((s64)i << PAGE_SHIFT));
> -               }
> +       for (i =3D 0; bio_size; i++) {
> +               unsigned int len =3D min_t(unsigned int, bio_size, PAGE_S=
IZE);
>
> -               if (!bio_add_page(bio, ws->pages[i], page_size, 0)) {
> -                       err =3D submit_bio_wait(bio);
> +               if (bio_add_page(bio, ws->pages[i], len, 0) !=3D len) {
> +                       err =3D -EIO;
>                         bio_put(bio);
> -                       if (err)
> -                               goto free_rlc;
> -                       bio =3D NULL;
> -                       goto setup_bio;
> +                       goto free_rlc;
>                 }
> -               i++;
> +               bio_size -=3D len;
>         }
>
>         err =3D submit_bio_wait(bio);
> --
> 2.34.1
>


--=20
Thanks,
Hyunchul