Currently, a patchset[1] is under review on the Linux kernel mailing lists, which introduces a new fs-level keyring. Once upstreamed, this patchset would enable cryptohome to manage unlocked directories and files by key, instead of clearing all caches wholesale. This issue tracks changes required to cryptohome to support the new interface and backporting the patchset to older branches.

[1] https://www.spinics.net/lists/keyrings/msg03101.html