+union fscrypt_iv {
+ /* usual IV format */
+ struct {
+ /* logical block number within the file */
+ __le64 block_number;
+
+ /* per-file nonce; only set in DIRECT_KEY mode */
+ u8 nonce[FILE_NONCE_SIZE];
+ };
+ /* IV format for IV_INO_LBLK_* modes */
+ struct {
+ /*
+ * IV_INO_LBLK_64: logical block number within the file
+ * IV_INO_LBLK_32: hashed inode number + logical block number
+ * within the file, mod 2^32
+ */
+ __le32 block_number32;
+
+ /* IV_INO_LBLK_64: inode number */
+ __le32 inode_number;