Re: [PATCH v3 0/3] f2fs: support encrypted inline data

[Eric Biggers <ebiggers@kernel.org>]

On Tue, Jun 16, 2026 at 05:46:12PM +0800, LiaoYuanhong-vivo wrote:
> Could you share more about the direction you have in mind for simplifying
> f2fs/ext4 contents encryption around blk-crypto?

Currently ext4 and f2fs each have two implementations of file contents
encryption and decryption:

- One where the en/decryption is done in the filesystem layer

- One where the filesystem attaches a bio_crypt_ctx to the bios and the
  en/decryption is done either in the block layer by blk-crypto-fallback
  or by inline encryption hardware

I'd like to drop the first one, for simplicity and to reduce the burden
on ongoing developments like large folio support.

> For f2fs inline_data, there is still a real space-saving benefit on phones,
> since many encrypted files are smaller than 4K. Is there any acceptable
> future direction to support this kind of inode-resident data with
> blk-crypto or hardware-wrapped keys?

It is incompatible with inline encryption hardware.  A CPU-based
solution like Intel Key Locker or RISC-V High Assurance Cryptography
could provide similar security properties.  But there's nothing for
arm64 yet.  And I should mention that no one has wanted to use Key
Locker anyway because it's really slow.

- Eric