Re: [PATCH 3/4] f2fs: add inline encryption support

[Eric Biggers <ebiggers@kernel.org>]

On Wed, Jun 17, 2020 at 07:57:31AM +0000, Satya Tangirala wrote:
> Wire up f2fs to support inline encryption via the helper functions which
> fs/crypto/ now provides.  This includes:
> 
> - Adding a mount option 'inlinecrypt' which enables inline encryption
>   on encrypted files where it can be used.
> 
> - Setting the bio_crypt_ctx on bios that will be submitted to an
>   inline-encrypted file.
> 
> - Not adding logically discontiguous data to bios that will be submitted
>   to an inline-encrypted file.
> 
> - Not doing filesystem-layer crypto on inline-encrypted files.
> 
> This patch includes a fix for a race during IPU by
> Sahitya Tummala <stummala@codeaurora.org>
> 
> Co-developed-by: Eric Biggers <ebiggers@google.com>
> Signed-off-by: Eric Biggers <ebiggers@google.com>
> Signed-off-by: Satya Tangirala <satyat@google.com>
> ---
>  Documentation/filesystems/f2fs.rst |  7 ++-
>  fs/f2fs/compress.c                 |  2 +-
>  fs/f2fs/data.c                     | 81 ++++++++++++++++++++++++------
>  fs/f2fs/super.c                    | 32 ++++++++++++
>  4 files changed, 104 insertions(+), 18 deletions(-)
> 
> diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst
> index 099d45ac8d8f..4dc36143ff82 100644
> --- a/Documentation/filesystems/f2fs.rst
> +++ b/Documentation/filesystems/f2fs.rst
> @@ -258,7 +258,12 @@ compress_extension=%s  Support adding specified extension, so that f2fs can enab
>                         on compression extension list and enable compression on
>                         these file by default rather than to enable it via ioctl.
>                         For other files, we can still enable compression via ioctl.
> -====================== ============================================================

The above line being deleted marks the end of a table, so it shouldn't be
deleted (it should go after the part below).

> +inlinecrypt
> +                       Encrypt/decrypt the contents of encrypted files using the
> +                       blk-crypto framework rather than filesystem-layer encryption.
> +                       This allows the use of inline encryption hardware. The on-disk
> +                       format is unaffected. For more details, see
> +                       Documentation/block/inline-encryption.rst.

Like I commented on one of the commit messages -- this doesn't make it clear
what happens in cases where blk-crypto can't be used.  Maybe just replace:
"Encrypt/decrypt" => "When possible, encrypt/decrypt".

Likewise for the ext4 documentation for this same mount option.

- Eric