Re: [PATCH 1/6] fs: Move clearing of mappedtodisk to buffer.c

[Jan Kara <jack@suse.cz>]

On Wed 02-10-24 05:01:03, Matthew Wilcox (Oracle) wrote:
> The mappedtodisk flag is only meaningful for buffer head based
> filesystems.  It should not be cleared for other filesystems.  This allows
> us to reuse the mappedtodisk flag to have other meanings in filesystems
> that do not use buffer heads.
> 
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

The patch looks good. But I'm bit confused about the changelog. There's no
generic code checking for mappedtodisk. Only nilfs2 actually uses it for
anything, all other filesystems just never look at it as far as my grepping
shows. So speaking about "filesystems that do not use buffer heads" looks
somewhat broad to me. Anyway feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
>  fs/buffer.c   | 1 +
>  mm/truncate.c | 1 -
>  2 files changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/buffer.c b/fs/buffer.c
> index 1fc9a50def0b..35f9af799e0a 100644
> --- a/fs/buffer.c
> +++ b/fs/buffer.c
> @@ -1649,6 +1649,7 @@ void block_invalidate_folio(struct folio *folio, size_t offset, size_t length)
>  	if (length == folio_size(folio))
>  		filemap_release_folio(folio, 0);
>  out:
> +	folio_clear_mappedtodisk(folio);
>  	return;
>  }
>  EXPORT_SYMBOL(block_invalidate_folio);
> diff --git a/mm/truncate.c b/mm/truncate.c
> index 0668cd340a46..870af79fb446 100644
> --- a/mm/truncate.c
> +++ b/mm/truncate.c
> @@ -166,7 +166,6 @@ static void truncate_cleanup_folio(struct folio *folio)
>  	 * Hence dirty accounting check is placed after invalidation.
>  	 */
>  	folio_cancel_dirty(folio);
> -	folio_clear_mappedtodisk(folio);
>  }
>  
>  int truncate_inode_folio(struct address_space *mapping, struct folio *folio)
> -- 
> 2.43.0
> 
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR