fscrypt: support test_dummy_encryption=v2

v1 encryption policies are deprecated in favor of v2, and some new
features (e.g. encryption+casefolding) are only being added for v2.

Therefore, the "test_dummy_encryption" mount option (which is used for
encryption I/O testing with xfstests) needs to support v2 policies.

To do this, extend its syntax to be "test_dummy_encryption=v1" or
"test_dummy_encryption=v2".  The existing "test_dummy_encryption" (no
argument) also continues to be accepted, to specify the default setting
-- currently v1, but the next patch changes it to v2.

To cleanly support both v1 and v2 while also making it easy to support
specifying other encryption settings in the future (say, accepting
"$contents_mode:$filenames_mode:v2"), make ext4 and f2fs maintain a
pointer to the dummy fscrypt_context rather than using mount flags.

To avoid concurrency issues, don't allow test_dummy_encryption to be set
or changed during a remount.  (The former restriction is new, but
xfstests doesn't run into it, so no one should notice.)

Tested with 'gce-xfstests -c {ext4,f2fs}/encrypt -g auto'.  On ext4,
there are two regressions, both of which are test bugs: ext4/023 and
ext4/028 fail because they set an xattr and expect it to be stored
inline, but the increase in size of the fscrypt_context from
24 to 40 bytes causes this xattr to be spilled into an external block.

Link: https://lore.kernel.org/r/[email protected]
Acked-by: Jaegeuk Kim <[email protected]>
Reviewed-by: Theodore Ts'o <[email protected]>
Signed-off-by: Eric Biggers <[email protected]>
This commit is contained in:
Eric Biggers 2020-05-12 16:32:50 -07:00 • committed by Jaegeuk Kim
commit 11a91a97bc
10 changed files with 308 additions and 60 deletions

View file

@ -217,8 +217,12 @@ fsync_mode=%s Control the policy of fsync. Currently supports "posix",
pass, but the performance will regress. "nobarrier" is
based on "posix", but doesn't issue flush command for
non-atomic files likewise "nobarrier" mount option.
test_dummy_encryption Enable dummy encryption, which provides a fake fscrypt
test_dummy_encryption
test_dummy_encryption=%s
Enable dummy encryption, which provides a fake fscrypt
context. The fake fscrypt context is used by xfstests.
The argument may be either "v1" or "v2", in order to
select the corresponding fscrypt policy version.
checkpoint=%s[:%u[%]] Set to "disable" to turn off checkpointing. Set to "enable"
to reenable checkpointing. Is enabled by default. While
disabled, any unmounting or unexpected shutdowns will cause