linux-ext4 - Re: [PATCH 10/11] fuse: update ki_pos in fuse_perform

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Date:   Wed, 24 May 2023 09:07:22 +0200
From:   Miklos Szeredi <miklos@...redi.hu>
To:     Christoph Hellwig <hch@....de>
Cc:     Matthew Wilcox <willy@...radead.org>, Jens Axboe <axboe@...nel.dk>,
        Xiubo Li <xiubli@...hat.com>,
        Ilya Dryomov <idryomov@...il.com>,
        Alexander Viro <viro@...iv.linux.org.uk>,
        Christian Brauner <brauner@...nel.org>,
        "Theodore Ts'o" <tytso@....edu>, Jaegeuk Kim <jaegeuk@...nel.org>,
        Chao Yu <chao@...nel.org>,
        Andreas Gruenbacher <agruenba@...hat.com>,
        "Darrick J. Wong" <djwong@...nel.org>,
        Trond Myklebust <trond.myklebust@...merspace.com>,
        Anna Schumaker <anna@...nel.org>,
        Damien Le Moal <dlemoal@...nel.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        linux-block@...r.kernel.org, ceph-devel@...r.kernel.org,
        linux-fsdevel@...r.kernel.org, linux-ext4@...r.kernel.org,
        linux-f2fs-devel@...ts.sourceforge.net, cluster-devel@...hat.com,
        linux-xfs@...r.kernel.org, linux-nfs@...r.kernel.org,
        linux-mm@...ck.org
Subject: Re: [PATCH 10/11] fuse: update ki_pos in fuse_perform_write

On Wed, 24 May 2023 at 08:38, Christoph Hellwig <hch@....de> wrote:
>
> Both callers of fuse_perform_write need to updated ki_pos, move it into
> common code.
>
> Signed-off-by: Christoph Hellwig <hch@....de>
> Reviewed-by: Damien Le Moal <dlemoal@...nel.org>
> ---
>  fs/fuse/file.c | 25 +++++++++++--------------
>  1 file changed, 11 insertions(+), 14 deletions(-)
>
> diff --git a/fs/fuse/file.c b/fs/fuse/file.c
> index 97d435874b14aa..90d587a7bdf813 100644
> --- a/fs/fuse/file.c
> +++ b/fs/fuse/file.c
> @@ -1329,7 +1329,10 @@ static ssize_t fuse_perform_write(struct kiocb *iocb,
>         fuse_write_update_attr(inode, pos, res);
>         clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
>
> -       return res > 0 ? res : err;
> +       if (!res)
> +               return err;
> +       iocb->ki_pos += res;
> +       return res;
>  }
>
>  static ssize_t fuse_cache_write_iter(struct kiocb *iocb, struct iov_iter *from)
> @@ -1375,41 +1378,35 @@ static ssize_t fuse_cache_write_iter(struct kiocb *iocb, struct iov_iter *from)
>                 goto out;
>
>         if (iocb->ki_flags & IOCB_DIRECT) {
> -               loff_t pos = iocb->ki_pos;
>                 written = generic_file_direct_write(iocb, from);
>                 if (written < 0 || !iov_iter_count(from))
>                         goto out;
>
> -               pos += written;
> -
> -               written_buffered = fuse_perform_write(iocb, mapping, from, pos);
> +               written_buffered = fuse_perform_write(iocb, mapping, from,
> +                                                     iocb->ki_pos);
>                 if (written_buffered < 0) {
>                         err = written_buffered;
>                         goto out;
>                 }
> -               endbyte = pos + written_buffered - 1;
> +               endbyte = iocb->ki_pos + written_buffered - 1;

Wrong endpos.

>
> -               err = filemap_write_and_wait_range(file->f_mapping, pos,
> +               err = filemap_write_and_wait_range(file->f_mapping,
> +                                                  iocb->ki_pos,

Wrong startpos.

>                                                    endbyte);
>                 if (err)
>                         goto out;
>
>                 invalidate_mapping_pages(file->f_mapping,
> -                                        pos >> PAGE_SHIFT,
> +                                        iocb->ki_pos >> PAGE_SHIFT,

Same here.

>                                          endbyte >> PAGE_SHIFT);
>
>                 written += written_buffered;
> -               iocb->ki_pos = pos + written_buffered;
> +               iocb->ki_pos += written_buffered;

Already added in fuse_perform_write().

>         } else {
>                 written = fuse_perform_write(iocb, mapping, from, iocb->ki_pos);
> -               if (written >= 0)
> -                       iocb->ki_pos += written;
>         }
>  out:
>         inode_unlock(inode);
> -       if (written > 0)
> -               written = generic_write_sync(iocb, written);
> -
>         return written ? written : err;
>  }
>
> --
> 2.39.2
>