On Fri, Jul 17, 2020 at 01:45:39AM +0000, Satya Tangirala wrote: > Update the fscrypt documentation file for inline encryption support. > > Signed-off-by: Satya Tangirala <satyat@xxxxxxxxxx> Reviewed-by: Eric Biggers <ebiggers@xxxxxxxxxx> > diff --git a/Documentation/filesystems/fscrypt.rst b/Documentation/filesystems/fscrypt.rst > index f5d8b0303ddf..f3d87a1a0a7f 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. > + Nit: most of the text in this file is formatted with textwidth=70. > 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 >
