Update the fscrypt documentation file for inline encryption support. Signed-off-by: Satya Tangirala <satyat@xxxxxxxxxx> Reviewed-by: Eric Biggers <ebiggers@xxxxxxxxxx> Reviewed-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> --- 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 1a6ad6f736b5..423c5a0daf45 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.rc0.142.g3c755180ce-goog
