Re: [PATCH] ecryptfs: use filemap_dirty_folio for address space operations

[Tyler Hicks <code@tyhicks.com>]

On 2026-07-03 09:00:44, Aditya Prakash Srivastava wrote:
> ecryptfs does not use buffer_heads. The legacy block_dirty_folio and
> block_invalidate_folio mapping operations were only added as a
> temporary compatibility fallback under CONFIG_BLOCK.
> 
> Since ecryptfs does not attach private metadata (such as buffer_heads)
> to its folios, block_dirty_folio is unnecessary.
> 
> Modernize ecryptfs to use filemap_dirty_folio for its dirty_folio
> address space operation. This allows removing the block_dirty_folio
> and block_invalidate_folio fallbacks, removing the buffer_head header
> include, and removing the CONFIG_BLOCK dependency inside ecryptfs_aops.
> 
> Signed-off-by: Aditya Prakash Srivastava <aditya.ansh182@gmail.com>

This looks correct to me and I've successfully ran the kernel tests in
the ecryptfs-utils test suite with the patch applied.

Adding Christoph for comment since this addresses the concern he
documented in the code comment below.

Tyler

> ---
>  fs/ecryptfs/mmap.c | 15 +--------------
>  1 file changed, 1 insertion(+), 14 deletions(-)
> 
> diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
> index 2c2b12fedeae..a057472b409c 100644
> --- a/fs/ecryptfs/mmap.c
> +++ b/fs/ecryptfs/mmap.c
> @@ -510,21 +510,8 @@ static sector_t ecryptfs_bmap(struct address_space *mapping, sector_t block)
>  	return block;
>  }
>  
> -#include <linux/buffer_head.h>
> -
>  const struct address_space_operations ecryptfs_aops = {
> -	/*
> -	 * XXX: This is pretty broken for multiple reasons: ecryptfs does not
> -	 * actually use buffer_heads, and ecryptfs will crash without
> -	 * CONFIG_BLOCK.  But it matches the behavior before the default for
> -	 * address_space_operations without the ->dirty_folio method was
> -	 * cleaned up, so this is the best we can do without maintainer
> -	 * feedback.
> -	 */
> -#ifdef CONFIG_BLOCK
> -	.dirty_folio	= block_dirty_folio,
> -	.invalidate_folio = block_invalidate_folio,
> -#endif
> +	.dirty_folio	= filemap_dirty_folio,
>  	.writepages = ecryptfs_writepages,
>  	.read_folio = ecryptfs_read_folio,
>  	.write_begin = ecryptfs_write_begin,
> -- 
> 2.47.3
>