[PATCH v3 3/3] f2fs: Handle casefolding with Encryption

[Eric Biggers]

On Wed, Nov 18, 2020 at 06:42:45AM +0000, Daniel Rosenberg wrote:
> Expand f2fs's casefolding support to include encrypted directories.  To
> index casefolded+encrypted directories, we use the SipHash of the
> casefolded name, keyed by a key derived from the directory's fscrypt
> master key.  This ensures that the dirhash doesn't leak information
> about the plaintext filenames.
> 
> Encryption keys are unavailable during roll-forward recovery, so we
> can't compute the dirhash when recovering a new dentry in an encrypted +
> casefolded directory.  To avoid having to force a checkpoint when a new
> file is fsync'ed, store the dirhash on-disk appended to i_name.
> 
> This patch incorporates work by Eric Biggers <ebiggers at google.com>
> and Jaegeuk Kim <jaegeuk at kernel.org>.
> 
> Co-developed-by: Eric Biggers <ebiggers at google.com>
> Signed-off-by: Eric Biggers <ebiggers at google.com>
> Signed-off-by: Daniel Rosenberg <drosen at google.com>

Looks good.  If it's needed (some may claim it's not needed because I have a
Co-developed-by), you can add:

	Reviewed-by: Eric Biggers <ebiggers at google.com>

- Eric