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References: <20240426103528.406063-1-chao@kernel.org>
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From: Daeho Jeong <daeho43@gmail.com>
Date: Fri, 26 Apr 2024 07:14:50 -0700
Message-ID: <CACOAw_xiC08JTanBSLaBED8_zveCEhoaDWeJ3YVU0h9+dNkQUg@mail.gmail.com>
Subject: Re: [PATCH] f2fs: zone: fix to don't trigger OPU on pinfile for
 direct IO
To: Chao Yu <chao@kernel.org>
Cc: jaegeuk@kernel.org, linux-f2fs-devel@lists.sourceforge.net, 
	linux-kernel@vger.kernel.org
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On Fri, Apr 26, 2024 at 3:35=E2=80=AFAM Chao Yu <chao@kernel.org> wrote:
>
> Otherwise, it breaks pinfile's sematics.
>
> Cc: Daeho Jeong <daeho43@gmail.com>
> Signed-off-by: Chao Yu <chao@kernel.org>
> ---
>  fs/f2fs/data.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index bee1e45f76b8..e29000d83d52 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -1596,7 +1596,8 @@ int f2fs_map_blocks(struct inode *inode, struct f2f=
s_map_blocks *map, int flag)
>
>         /* use out-place-update for direct IO under LFS mode */
>         if (map->m_may_create &&
> -           (is_hole || (f2fs_lfs_mode(sbi) && flag =3D=3D F2FS_GET_BLOCK=
_DIO))) {
> +           (is_hole || (flag =3D=3D F2FS_GET_BLOCK_DIO && (f2fs_lfs_mode=
(sbi) &&
> +           (!f2fs_sb_has_blkzoned(sbi) || !f2fs_is_pinned_file(inode))))=
)) {
>                 if (unlikely(f2fs_cp_error(sbi))) {
>                         err =3D -EIO;
>                         goto sync_out;
> --
> 2.40.1

So, we block overwrite io for the pinfile here.

static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *fr=
om)

{
..
        if (f2fs_is_pinned_file(inode) &&
            !f2fs_overwrite_io(inode, pos, count)) {
                ret =3D -EIO;
                goto out_unlock;
        }


>