[Devel] [PATCH VZ10 1/2] fs/fuse: restore fuse_writepages() to mainstream behavior

[Alexey Kuznetsov]

Ack

On Mon, Apr 20, 2026 at 3:26 PM Liu Kui <kui.liu at virtuozzo.com> wrote:
>
> Restore fuse_writepages() and fuse_writepages_fill() to their original
> behavior by removing changes from commit "67d9ccc4cc1d fuse: fix
> writeback/release race". These changes make no sense at all, in particular
> set err to 0 even after write_cache_pages() returns an error is just
> wrong. The original commit should have been dropped as indicated by
> "083cb0ac8e38 fuse: Wait inflight requests"
>
> Signed-off-by: Liu Kui <kui.liu at virtuozzo.com>
> ---
>  fs/fuse/file.c | 27 +++++++++------------------
>  1 file changed, 9 insertions(+), 18 deletions(-)
>
> diff --git a/fs/fuse/file.c b/fs/fuse/file.c
> index 11fb3996a2ac..b84aac13bfc9 100644
> --- a/fs/fuse/file.c
> +++ b/fs/fuse/file.c
> @@ -1233,7 +1233,7 @@ void fuse_release_ff(struct inode *inode, struct fuse_file *ff)
>                         struct fuse_inode *fi = get_fuse_inode(inode);
>                         spin_lock(&fi->lock);
>                         __fuse_file_put(ff);
> -                       wake_up(&get_fuse_inode(inode)->page_waitq);
> +                       wake_up(&fi->page_waitq);
>                         spin_unlock(&fi->lock);
>                 } else {
>                         fuse_file_put(ff, false);
> @@ -2724,17 +2724,20 @@ static int fuse_writepages_fill(struct folio *folio,
>         int err;
>         int check_for_blocked = 0;
>
> -       BUG_ON(wpa && !data->ff);
> -
>         if (!wpa && test_bit(FUSE_I_INVAL_FILES, &fi->state)) {
>                 unlock_page(&folio->page);
>                 return -EIO;
>         }
>
> +       if (!data->ff) {
> +               err = -EIO;
> +               data->ff = fuse_write_file_get(fi);
> +               if (!data->ff)
> +                       goto out_unlock;
> +       }
> +
>         if (wpa && fuse_writepage_need_send(fc, &folio->page, ap, data)) {
>                 fuse_writepages_send(data);
> -               fuse_release_ff(inode, data->ff);
> -               data->ff = NULL;
>                 data->wpa = NULL;
>         }
>
> @@ -2757,13 +2760,6 @@ static int fuse_writepages_fill(struct folio *folio,
>          * under writeback, so we can release the page lock.
>          */
>         if (data->wpa == NULL) {
> -               /* we can acquire ff here because we do have locked pages here! */
> -               BUG_ON(data->ff);
> -               err = -EIO;
> -               data->ff = fuse_write_file_get(fi);
> -               if (!data->ff)
> -                       goto out_unlock;
> -
>                 err = -ENOMEM;
>                 wpa = fuse_writepage_args_setup(folio, data->ff);
>                 if (!wpa) {
> @@ -2794,8 +2790,6 @@ static int fuse_writepages_fill(struct folio *folio,
>                 data->wpa = wpa;
>         } else {
>                 folio_end_writeback(folio);
> -               fuse_release_ff(inode, data->ff);
> -               data->ff = NULL;
>         }
>  out_unlock:
>         folio_unlock(folio);
> @@ -2845,11 +2839,8 @@ static int fuse_writepages(struct address_space *mapping,
>         if (data.wpa) {
>                 WARN_ON(!data.wpa->ia.ap.num_pages);
>                 fuse_writepages_send(&data);
> -               fuse_release_ff(inode, data.ff);
> -               data.ff = NULL;
> -               err = 0;
>         }
> -       BUG_ON(data.ff);
> +       fuse_release_ff(inode, data.ff);
>
>         kfree(data.orig_pages);
>  out:
> --
> 2.39.5 (Apple Git-154)