[PATCH] ext4: reserve codepoints used by the ext4 encryption feature

Theodore Ts'o
2015-01-23T19:36:24Z

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
---
fs/ext4/ext4.h | 17 +++++++++++++----
1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index a75fba6..b7f393d 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -364,7 +364,8 @@ struct flex_groups {
#define EXT4_DIRTY_FL 0x00000100
#define EXT4_COMPRBLK_FL 0x00000200 /* One or more compressed clusters */
#define EXT4_NOCOMPR_FL 0x00000400 /* Don't compress */
-#define EXT4_ECOMPR_FL 0x00000800 /* Compression error */
+ /* nb: was previously EXT2_ECOMPR_FL */
+#define EXT4_ENCRYPT_FL 0x00000800 /* encrypted file */
/* End compression flags --- maybe not all used */
#define EXT4_INDEX_FL 0x00001000 /* hash-indexed directory */
#define EXT4_IMAGIC_FL 0x00002000 /* AFS directory */
@@ -421,7 +422,7 @@ enum {
EXT4_INODE_DIRTY = 8,
EXT4_INODE_COMPRBLK = 9, /* One or more compressed clusters */
EXT4_INODE_NOCOMPR = 10, /* Don't compress */
- EXT4_INODE_ECOMPR = 11, /* Compression error */
+ EXT4_INODE_ENCRYPT = 11, /* Compression error */
/* End compression flags --- maybe not all used */
EXT4_INODE_INDEX = 12, /* hash-indexed directory */
EXT4_INODE_IMAGIC = 13, /* AFS directory */
@@ -466,7 +467,7 @@ static inline void ext4_check_flag_values(void)
CHECK_FLAG_VALUE(DIRTY);
CHECK_FLAG_VALUE(COMPRBLK);
CHECK_FLAG_VALUE(NOCOMPR);
- CHECK_FLAG_VALUE(ECOMPR);
+ CHECK_FLAG_VALUE(ENCRYPT);
CHECK_FLAG_VALUE(INDEX);
CHECK_FLAG_VALUE(IMAGIC);
CHECK_FLAG_VALUE(JOURNAL_DATA);
@@ -1043,6 +1044,12 @@ extern void ext4_set_bits(void *bm, int cur, int len);
/* Metadata checksum algorithm codes */
#define EXT4_CRC32C_CHKSUM 1

+/* Encryption algorithms */
+#define EXT4_ENCRYPTION_MODE_INVALID 0
+#define EXT4_ENCRYPTION_MODE_AES_256_XTS 1
+#define EXT4_ENCRYPTION_MODE_AES_256_GCM 2
+#define EXT4_ENCRYPTION_MODE_AES_256_CBC 3
+
/*
* Structure of the super block
*/
@@ -1156,7 +1163,8 @@ struct ext4_super_block {
__le32 s_grp_quota_inum; /* inode for tracking group quota */
__le32 s_overhead_clusters; /* overhead blocks/clusters in fs */
__le32 s_backup_bgs[2]; /* groups with sparse_super2 SBs */
- __le32 s_reserved[106]; /* Padding to the end of the block */
+ __u8 s_encrypt_algos[4]; /* Encryption algorithms in use */
+ __le32 s_reserved[105]; /* Padding to the end of the block */
__le32 s_checksum; /* crc32c(superblock) */
};

@@ -1537,6 +1545,7 @@ static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
#define EXT4_FEATURE_INCOMPAT_BG_USE_META_CSUM 0x2000 /* use crc32c for bg */
#define EXT4_FEATURE_INCOMPAT_LARGEDIR 0x4000 /* >2GB or 3-lvl htree */
#define EXT4_FEATURE_INCOMPAT_INLINE_DATA 0x8000 /* data in inode */
+#define EXT4_FEATURE_INCOMPAT_ENCRYPT 0x10000

#define EXT2_FEATURE_COMPAT_SUPP EXT4_FEATURE_COMPAT_EXT_ATTR
#define EXT2_FEATURE_INCOMPAT_SUPP (EXT4_FEATURE_INCOMPAT_FILETYPE| \
--
2.1.0