diff --git a/libc/kernel/uapi/linux/fs.h b/libc/kernel/uapi/linux/fs.h
index d27c9e8..75c17a4 100644
--- a/libc/kernel/uapi/linux/fs.h
+++ b/libc/kernel/uapi/linux/fs.h
@@ -99,6 +99,7 @@
 #define MS_I_VERSION (1 << 23)
 #define MS_STRICTATIME (1 << 24)
 #define MS_LAZYTIME (1 << 25)
+#define MS_SUBMOUNT (1 << 26)
 #define MS_NOREMOTELOCK (1 << 27)
 #define MS_NOSEC (1 << 28)
 #define MS_BORN (1 << 29)
@@ -198,10 +199,18 @@
   __u8 filenames_encryption_mode;
   __u8 flags;
   __u8 master_key_descriptor[FS_KEY_DESCRIPTOR_SIZE];
-} __packed;
+};
 #define FS_IOC_SET_ENCRYPTION_POLICY _IOR('f', 19, struct fscrypt_policy)
 #define FS_IOC_GET_ENCRYPTION_PWSALT _IOW('f', 20, __u8[16])
 #define FS_IOC_GET_ENCRYPTION_POLICY _IOW('f', 21, struct fscrypt_policy)
+#define FS_KEY_DESC_PREFIX "fscrypt:"
+#define FS_KEY_DESC_PREFIX_SIZE 8
+#define FS_MAX_KEY_SIZE 64
+struct fscrypt_key {
+  __u32 mode;
+  __u8 raw[FS_MAX_KEY_SIZE];
+  __u32 size;
+};
 #define FS_SECRM_FL 0x00000001
 #define FS_UNRM_FL 0x00000002
 #define FS_COMPR_FL 0x00000004