Re: [PATCH 2/3] ntfs: redirty folio when ntfs_write_mft_block() runs out of memory

[Hyunchul Lee]

2026년 5월 1일 (금) 오전 2:21, DaeMyung Kang <charsyam@xxxxxxxxx>님이 작성:
>
> ntfs_write_mft_block() is called by writeback_iter() with the folio
> locked.  When the per-call allocations for @locked_nis or @ref_inos
> fail, the function returns -ENOMEM directly without unlocking the
> folio.  Any later task that needs the folio's lock then stalls, and
> the folio's dirty state is silently lost from the writeback
> iterator's point of view.
>
> Use folio_redirty_for_writepage() so the folio remains dirty for a
> subsequent writeback pass, unlock it, and only then return -ENOMEM
> so the caller can propagate the error to fsync()/sync_filesystem().
>
> Fixes: f462fdf3d6a4 ("ntfs: reduce stack usage in ntfs_write_mft_block()")
> Signed-off-by: DaeMyung Kang <charsyam@xxxxxxxxx>

Looks good to me.

Reviewed-by: Hyunchul Lee <hyc.lee@xxxxxxxxx>


> ---
>  fs/ntfs/mft.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/fs/ntfs/mft.c b/fs/ntfs/mft.c
> index 4051b4823162..00f172fd1b21 100644
> --- a/fs/ntfs/mft.c
> +++ b/fs/ntfs/mft.c
> @@ -2740,8 +2740,11 @@ static int ntfs_write_mft_block(struct folio *folio, struct writeback_control *w
>         ntfs_debug("Entering for inode 0x%llx, attribute type 0x%x, folio index 0x%lx.",
>                         ni->mft_no, ni->type, folio->index);
>
> -       if (!locked_nis || !ref_inos)
> +       if (!locked_nis || !ref_inos) {
> +               folio_redirty_for_writepage(wbc, folio);
> +               folio_unlock(folio);
>                 return -ENOMEM;
> +       }
>
>         /* We have to zero every time due to mmap-at-end-of-file. */
>         if (folio->index >= (i_size >> folio_shift(folio)))
> --
> 2.43.0
>


--
Thanks,
Hyunchul