Re: [PATCH] fscrypt: support decrypting data from large folios

[Eric Biggers <ebiggers@kernel.org>]

On Fri, Jan 27, 2023 at 02:42:02PM -0800, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@google.com>
> 
> Try to make the filesystem-level decryption functions in fs/crypto/
> aware of large folios.  This includes making fscrypt_decrypt_bio()
> support the case where the bio contains large folios, and making
> fscrypt_decrypt_pagecache_blocks() take a folio instead of a page.
> 
> There's no way to actually test this with large folios yet, but I've
> tested that this doesn't cause any regressions.
> 
> Note that this patch just handles *decryption*, not encryption which
> will be a little more difficult.
> 
> Signed-off-by: Eric Biggers <ebiggers@google.com>
> ---
>  Documentation/filesystems/fscrypt.rst |  4 ++--
>  fs/buffer.c                           |  4 ++--
>  fs/crypto/bio.c                       | 10 ++++------
>  fs/crypto/crypto.c                    | 28 ++++++++++++++-------------
>  fs/ext4/inode.c                       |  6 ++++--
>  include/linux/fscrypt.h               |  9 ++++-----
>  6 files changed, 31 insertions(+), 30 deletions(-)

Applied to https://git.kernel.org/pub/scm/fs/fsverity/linux.git/log/?h=for-next

(I used the fsverity tree instead of the fscrypt tree, so that I could resolve
the conflict with "fs/buffer.c: support fsverity in block_read_full_folio()" in
the fsverity tree.)

- Eric