Re: [PATCH v4 6/7] fscrypt: document inline encryption support

Jaegeuk Kim
2020-07-22T17:01:47Z

On 07/20, Satya Tangirala wrote:
> Update the fscrypt documentation file for inline encryption support.
>
> Signed-off-by: Satya Tangirala <satyat@google.com>
> Reviewed-by: Eric Biggers <ebiggers@google.com>

Reviewed-by: Jaegeuk Kim <jaegeuk@kernel.org>

> ---
> Documentation/filesystems/fscrypt.rst | 16 +++++++++++++++-
> 1 file changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/filesystems/fscrypt.rst b/Documentation/filesystems/fscrypt.rst
> index f5d8b0303ddf..ec81598477fc 100644
> --- a/Documentation/filesystems/fscrypt.rst
> +++ b/Documentation/filesystems/fscrypt.rst
> @@ -1204,6 +1204,18 @@ buffer. Some filesystems, such as UBIFS, already use temporary
> buffers regardless of encryption. Other filesystems, such as ext4 and
> F2FS, have to allocate bounce pages specially for encryption.
>
> +Fscrypt is also able to use inline encryption hardware instead of the
> +kernel crypto API for en/decryption of file contents. When possible,
> +and if directed to do so (by specifying the 'inlinecrypt' mount option
> +for an ext4/F2FS filesystem), it adds encryption contexts to bios and
> +uses blk-crypto to perform the en/decryption instead of making use of
> +the above read/write path changes. Of course, even if directed to
> +make use of inline encryption, fscrypt will only be able to do so if
> +either hardware inline encryption support is available for the
> +selected encryption algorithm or CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK
> +is selected. If neither is the case, fscrypt will fall back to using
> +the above mentioned read/write path changes for en/decryption.
> +
> Filename hashing and encoding
> -----------------------------
>
> @@ -1250,7 +1262,9 @@ Tests
>
> To test fscrypt, use xfstests, which is Linux's de facto standard
> filesystem test suite. First, run all the tests in the "encrypt"
> -group on the relevant filesystem(s). For example, to test ext4 and
> +group on the relevant filesystem(s). One can also run the tests
> +with the 'inlinecrypt' mount option to test the implementation for
> +inline encryption support. For example, to test ext4 and
> f2fs encryption using `kvm-xfstests
> <https://github.com/tytso/xfstests-bld/blob/master/Documentation/kvm-quickstart.md>`_::
>
> --
> 2.28.0.rc0.105.gf9edc3c819-goog