Re: [PATCH v2 2/6] iomap: support invalidating partial folios

From: Darrick J. Wong
Date: Mon Aug 12 2024 - 12:55:48 EST


On Mon, Aug 12, 2024 at 08:11:55PM +0800, Zhang Yi wrote:
> From: Zhang Yi <yi.zhang@xxxxxxxxxx>
>
> Current iomap_invalidate_folio() could only invalidate an entire folio,
> if we truncate a partial folio on a filesystem with blocksize < folio
> size, it will left over the dirty bits of truncated/punched blocks, and
> the write back process will try to map the invalid hole range, but
> fortunately it hasn't trigger any real problems now since ->map_blocks()
> will fix the length. Fix this by supporting invalidating partial folios.
>
> Signed-off-by: Zhang Yi <yi.zhang@xxxxxxxxxx>

Seems ok to me
Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>

--D

> ---
> fs/iomap/buffered-io.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> index 4da453394aaf..763deabe8331 100644
> --- a/fs/iomap/buffered-io.c
> +++ b/fs/iomap/buffered-io.c
> @@ -644,6 +644,8 @@ void iomap_invalidate_folio(struct folio *folio, size_t offset, size_t len)
> WARN_ON_ONCE(folio_test_writeback(folio));
> folio_cancel_dirty(folio);
> ifs_free(folio);
> + } else {
> + iomap_clear_range_dirty(folio, offset, len);
> }
> }
> EXPORT_SYMBOL_GPL(iomap_invalidate_folio);
> --
> 2.39.2
>
>