This changeset adds extent-based data encryption to fscrypt. Some filesystems need to encrypt data based on extents, rather than on inodes, due to features incompatible with inode-based encryption. For instance, btrfs can have multiple inodes referencing a single block of data, and moves logical data blocks to different physical locations on disk in the background. As per discussion last year in [1] and later in [2], we would like to allow the use of fscrypt with btrfs, with authenticated encryption. This is the first step of that work, adding extent-based encryption to fscrypt; authenticated encryption is the next step. Extent-based encryption should be usable by other filesystems which wish to support snapshotting or background data rearrangement also, but btrfs is the first user. This changeset requires extent encryption to use inlinecrypt, as discussed previously. There are two questionable parts: the forget_extent_info hook is not yet in use by btrfs, as I haven't yet written a test exercising a race where it would be relevant; and saving the session key credentials just to enable v1 session-based policies is perhaps less good than This applies atop [3], which itself is based on kdave/misc-next. It passes encryption fstests with suitable changes to btrfs-progs and tests. [1] https://docs.google.com/document/d/1janjxewlewtVPqctkWOjSa7OhCgB8Gdx7iDaCDQQNZA/edit?usp=sharing [2] https://lore.kernel.org/linux-fscrypt/80496cfe-161d-fb0d-8230-93818b966b1b@xxxxxxxxxx/T/#t [3] https://lore.kernel.org/linux-fscrypt/cover.1688927423.git.sweettea-kernel@xxxxxxxxxx/ Changelog: v2: - Change to soft-delete keys in use by inodes using extent encryption at key removal time (new changes 9 and 10), as per feedback. - Add a missing error check in fscrypt_mergeable_bio (change 3) v1: - https://lore.kernel.org/linux-fscrypt/248eac32-96cc-eb2e-85da-422a8d75a376@xxxxxxxxxx/T/#t Sweet Tea Dorminy (14): fscrypt: factor helper for locking master key fscrypt: factor getting info for a specific block fscrypt: adjust effective lblks based on extents fscrypt: add a super_block pointer to fscrypt_info fscrypt: setup leaf inodes for extent encryption fscrypt: allow infos to be owned by extents fscrypt: notify per-extent infos if master key vanishes fscrypt: use an optional ino equivalent for per-extent infos fscrypt: move function call warning of busy inodes fscrypt: revamp key removal for extent encryption fscrypt: add creation/usage/freeing of per-extent infos fscrypt: allow load/save of extent contexts fscrypt: save session key credentials for extent infos fscrypt: update documentation for per-extent keys Documentation/filesystems/fscrypt.rst | 43 +++- fs/crypto/crypto.c | 6 +- fs/crypto/fscrypt_private.h | 128 +++++++++++- fs/crypto/inline_crypt.c | 28 ++- fs/crypto/keyring.c | 79 +++++--- fs/crypto/keysetup.c | 274 ++++++++++++++++++++++---- fs/crypto/keysetup_v1.c | 7 +- fs/crypto/policy.c | 20 ++ include/linux/fscrypt.h | 65 ++++++ 9 files changed, 562 insertions(+), 88 deletions(-) base-commit: e0144e6be2ec62c8d874076a6292a8d83b00ee32 prerequisite-patch-id: ab342a72cf967dadfb8bec1320c5906fd3c6800f prerequisite-patch-id: ced2a9dab36539f55c14cd74a28950087c475ff2 prerequisite-patch-id: d4f1a64c994c2fa0d2d4cab83f9ddff52f0622e9 prerequisite-patch-id: 1af0fc98277159b31c26bc5751663efc0d322d75 prerequisite-patch-id: 3b21b62208587486cf9b31618f7c3bc875362f1a prerequisite-patch-id: c43d693f5b7c498a876d9ffcfc49c11a8ca93d80 prerequisite-patch-id: f120bde1cf47fbef1d9f8fd09cdcccc1408c3ff4 prerequisite-patch-id: c6a1f087d4a67b928b9c6af04e00310bfa74ace1 -- 2.40.1
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