ext4: add support for IV_INO_LBLK_64 encryption policies
IV_INO_LBLK_64 encryption policies have special requirements from the
filesystem beyond those of the existing encryption policies:
- Inode numbers must never change, even if the filesystem is resized.
- Inode numbers must be <= 32 bits.
- File logical block numbers must be <= 32 bits.
ext4 has 32-bit inode and file logical block numbers. However,
resize2fs can re-number inodes when shrinking an ext4 filesystem.
However, typically the people who would want to use this format don't
care about filesystem shrinking. They'd be fine with a solution that
just prevents the filesystem from being shrunk.
Therefore, add a new feature flag EXT4_FEATURE_COMPAT_STABLE_INODES that
will do exactly that. Then wire up the fscrypt_operations to expose
this flag to fs/crypto/, so that it allows IV_INO_LBLK_64 policies when
this flag is set.
Acked-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
2 files changed
