reserve-codepoints-used-by-the-ext4-encryption-feature

   1 ext4 crypto: reserve codepoints used by the ext4 encryption feature
   2
   3 From: Theodore Ts'o <tytso@mit.edu>
   4
   5 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
   6 ---
   7  fs/ext4/ext4.h | 16 +++++++++++++---
   8  1 file changed, 13 insertions(+), 3 deletions(-)
   9
  10 diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
  11 index f7f3f58..e168382 100644
  12 --- a/fs/ext4/ext4.h
  13 +++ b/fs/ext4/ext4.h
  14 @@ -422,7 +422,7 @@ enum {
  15         EXT4_INODE_DIRTY        = 8,
  16         EXT4_INODE_COMPRBLK     = 9,    /* One or more compressed clusters */
  17         EXT4_INODE_NOCOMPR      = 10,   /* Don't compress */
  18 -       EXT4_INODE_ENCRYPT      = 11,   /* Compression error */
  19 +       EXT4_INODE_ENCRYPT      = 11,   /* Encrypted file */
  20  /* End compression flags --- maybe not all used */
  21         EXT4_INODE_INDEX        = 12,   /* hash-indexed directory */
  22         EXT4_INODE_IMAGIC       = 13,   /* AFS directory */
  23 @@ -582,6 +582,13 @@ enum {
  24  #define EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER  0x0010
  25  #define EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER   0x0020
  26
  27 +/* Encryption algorithms */
  28 +#define EXT4_ENCRYPTION_MODE_INVALID           0
  29 +#define EXT4_ENCRYPTION_MODE_AES_256_XTS       1
  30 +#define EXT4_ENCRYPTION_MODE_AES_256_GCM       2
  31 +#define EXT4_ENCRYPTION_MODE_AES_256_CBC       3
  32 +#define EXT4_ENCRYPTION_MODE_AES_256_CTS       4
  33 +
  34  /*
  35   * ioctl commands
  36   */
  37 @@ -1142,7 +1149,8 @@ struct ext4_super_block {
  38         __le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
  39         __u8    s_log_groups_per_flex;  /* FLEX_BG group size */
  40         __u8    s_checksum_type;        /* metadata checksum algorithm used */
  41 -       __le16  s_reserved_pad;
  42 +       __u8    s_encryption_level;     /* versioning level for encryption */
  43 +       __u8    s_reserved_pad;         /* Padding to next 32bits */
  44         __le64  s_kbytes_written;       /* nr of lifetime kilobytes written */
  45         __le32  s_snapshot_inum;        /* Inode number of active snapshot */
  46         __le32  s_snapshot_id;          /* sequential ID of active snapshot */
  47 @@ -1169,7 +1177,9 @@ struct ext4_super_block {
  48         __le32  s_overhead_clusters;    /* overhead blocks/clusters in fs */
  49         __le32  s_backup_bgs[2];        /* groups with sparse_super2 SBs */
  50         __u8    s_encrypt_algos[4];     /* Encryption algorithms in use  */
  51 -       __le32  s_reserved[105];        /* Padding to the end of the block */
  52 +       __u8    s_encrypt_pw_salt[16];  /* Salt used for string2key algorithm */
  53 +       __le32  s_lpf_ino;              /* Location of the lost+found inode */
  54 +       __le32  s_reserved[100];        /* Padding to the end of the block */
  55         __le32  s_checksum;             /* crc32c(superblock) */
  56  };
  57