Re: [PATCH v6 8/8] fscrypt: make prepared keys record their type

[Josef Bacik <josef@toxicpanda.com>]

On Tue, Aug 08, 2023 at 01:08:08PM -0400, Sweet Tea Dorminy wrote:
> Right now fscrypt_infos have two fields dedicated solely to recording
> what type of prepared key the info has: whether it solely owns the
> prepared key, or has borrowed it from a master key, or from a direct
> key.
> 
> The ci_direct_key field is only used for v1 direct key policies,
> recording the direct key that needs to have its refcount reduced when
> the crypt_info is freed. However, now that crypt_info->ci_enc_key is a
> pointer to the authoritative prepared key -- embedded in the direct key,
> in this case, we no longer need to keep a full pointer to the direct key
> -- we can use container_of() to go from the prepared key to its
> surrounding direct key.
> 
> The key ownership information doesn't change during the lifetime of a
> prepared key.  Since at worst there's a prepared key per info, and at
> best many infos share a single prepared key, it can be slightly more
> efficient to store this ownership info in the prepared key instead of in
> the fscrypt_info, especially since we can squash both fields down into
> a single enum.
> 
> Signed-off-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>

Reviewed-by: Josef Bacik <josef@toxicpanda.com>

Thanks,

Josef