From: Eric Biggers <ebiggers@kernel.org>
To: linux-ext4@vger.kernel.org
Cc: linux-fscrypt@vger.kernel.org, linux-fsdevel@vger.kernel.org,
Chandan Rajendra <chandan@linux.ibm.com>
Subject: [PATCH 0/2] ext4: support encryption with blocksize != PAGE_SIZE
Date: Wed, 16 Oct 2019 15:11:40 -0700 [thread overview]
Message-ID: <20191016221142.298754-1-ebiggers@kernel.org> (raw)
Hello,
This patchset makes ext4 support encryption on filesystems where the
filesystem block size is not equal to PAGE_SIZE. This allows e.g.
PowerPC systems to use ext4 encryption.
Most of the work for this was already done in prior kernel releases; now
the only part missing is decryption support in block_read_full_page().
Chandan Rajendra has proposed a patchset "Consolidate FS read I/O
callbacks code" [1] to address this and do various other things like
make ext4 use mpage_readpages() again, and make ext4 and f2fs share more
code. But it doesn't seem to be going anywhere.
Therefore, I propose we simply add decryption support to
block_read_full_page() for now. This is a fairly small change, and it
gets ext4 encryption with subpage-sized blocks working.
Note: to keep things simple I'm just allocating the work object from the
bi_end_io function with GFP_ATOMIC. But if people think it's necessary,
it could be changed to use preallocation like the page-based read path.
Tested with 'gce-xfstests -c ext4/encrypt_1k -g auto', using the new
"encrypt_1k" config I created. All tests pass except for those that
already fail or are excluded with the encrypt or 1k configs, and 2 tests
that try to create 1023-byte symlinks which fails since encrypted
symlinks are limited to blocksize-3 bytes. Also ran the dedicated
encryption tests using 'kvm-xfstests -c ext4/1k -g encrypt'; all pass,
including the on-disk ciphertext verification tests.
[1] https://lkml.kernel.org/linux-fsdevel/20190910155115.28550-1-chandan@linux.ibm.com/T/#u
Chandan Rajendra (1):
ext4: Enable encryption for subpage-sized blocks
Eric Biggers (1):
fs/buffer.c: support fscrypt in block_read_full_page()
Documentation/filesystems/fscrypt.rst | 4 +--
fs/buffer.c | 47 ++++++++++++++++++++++++---
fs/ext4/super.c | 7 ----
3 files changed, 44 insertions(+), 14 deletions(-)
--
2.23.0
next reply other threads:[~2019-10-16 22:14 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-16 22:11 Eric Biggers [this message]
2019-10-16 22:11 ` [PATCH 1/2] fs/buffer.c: support fscrypt in block_read_full_page() Eric Biggers
2019-10-19 3:16 ` Eric Biggers
2019-10-16 22:11 ` [PATCH 2/2] ext4: Enable encryption for subpage-sized blocks Eric Biggers
2019-10-17 6:14 ` [PATCH 0/2] ext4: support encryption with blocksize != PAGE_SIZE Chandan Rajendra
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