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authorEric Biggers <ebiggers@google.com>2019-10-25 00:54:37 +0300
committerEric Biggers <ebiggers@google.com>2019-11-06 23:34:42 +0300
commitb925acb8f83d7ce3582b34018c05aae1be666abf (patch)
treea60000768b7455c72cdf7aebb623191506d11634 /fs
parentb103fb7653fff09e7a6fb6ba9398a41584e7ae36 (diff)
downloadlinux-b925acb8f83d7ce3582b34018c05aae1be666abf.tar.xz
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>
Diffstat (limited to 'fs')
-rw-r--r--fs/ext4/ext4.h2
-rw-r--r--fs/ext4/super.c14
2 files changed, 16 insertions, 0 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 03db3e71676c..b3a2cc7c0252 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1678,6 +1678,7 @@ static inline bool ext4_verity_in_progress(struct inode *inode)
#define EXT4_FEATURE_COMPAT_RESIZE_INODE 0x0010
#define EXT4_FEATURE_COMPAT_DIR_INDEX 0x0020
#define EXT4_FEATURE_COMPAT_SPARSE_SUPER2 0x0200
+#define EXT4_FEATURE_COMPAT_STABLE_INODES 0x0800
#define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER 0x0001
#define EXT4_FEATURE_RO_COMPAT_LARGE_FILE 0x0002
@@ -1779,6 +1780,7 @@ EXT4_FEATURE_COMPAT_FUNCS(xattr, EXT_ATTR)
EXT4_FEATURE_COMPAT_FUNCS(resize_inode, RESIZE_INODE)
EXT4_FEATURE_COMPAT_FUNCS(dir_index, DIR_INDEX)
EXT4_FEATURE_COMPAT_FUNCS(sparse_super2, SPARSE_SUPER2)
+EXT4_FEATURE_COMPAT_FUNCS(stable_inodes, STABLE_INODES)
EXT4_FEATURE_RO_COMPAT_FUNCS(sparse_super, SPARSE_SUPER)
EXT4_FEATURE_RO_COMPAT_FUNCS(large_file, LARGE_FILE)
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index dd654e53ba3d..b3cbf8622eab 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1345,6 +1345,18 @@ static bool ext4_dummy_context(struct inode *inode)
return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
}
+static bool ext4_has_stable_inodes(struct super_block *sb)
+{
+ return ext4_has_feature_stable_inodes(sb);
+}
+
+static void ext4_get_ino_and_lblk_bits(struct super_block *sb,
+ int *ino_bits_ret, int *lblk_bits_ret)
+{
+ *ino_bits_ret = 8 * sizeof(EXT4_SB(sb)->s_es->s_inodes_count);
+ *lblk_bits_ret = 8 * sizeof(ext4_lblk_t);
+}
+
static const struct fscrypt_operations ext4_cryptops = {
.key_prefix = "ext4:",
.get_context = ext4_get_context,
@@ -1352,6 +1364,8 @@ static const struct fscrypt_operations ext4_cryptops = {
.dummy_context = ext4_dummy_context,
.empty_dir = ext4_empty_dir,
.max_namelen = EXT4_NAME_LEN,
+ .has_stable_inodes = ext4_has_stable_inodes,
+ .get_ino_and_lblk_bits = ext4_get_ino_and_lblk_bits,
};
#endif