--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/interface/fs.dg	Wed Jan 29 15:58:12 2020 +0900
@@ -0,0 +1,38 @@
+typedef struct fs<Type,Impl> {
+    union Data* fs;
+    int dev;
+    struct superblock* sb;
+    uint dev;
+    short type;
+    struct inode* ip;
+    struct stat* st;
+    char* dst;
+    uint off;
+    uint n;
+    const char* s;
+    const char* t;
+    struct inode* dp;
+    char* name;
+    uint* poff;
+    uint inum;
+    char* path;
+
+    __code readsb(Impl* fs, int dev, struct superblock* sb, __code next(...));
+    __code iinit(Impl* fs, __code next(...));
+    __code ialloc(Impl* fs, uint dev, short type, __code next(...));
+    __code iupdate(Impl* fs, struct inode* ip, __code next(...));
+    __code idup(Impl* fs, struct inode* ip, __code next(...));
+    __code ilock(Impl* fs, struct inode* ip, __code next(...));
+    __code iunlock(Impl* fs, struct inode* ip, __code next(...));
+    __code iput(Impl* fs, struct inode* ip, __code next(...));
+    __code iunlockput(Impl* fs, struct inode* ip, __code next(...));
+    __code stati(Impl* fs , struct inode* ip, struct stat* st, __code next(...));
+    __code readi(Impl* fs, struct inode* ip, char* dst, uint off, uint n, __code next(...));
+    __code writei(Impl* fs, struct inode* ip, char* src, uint off, uint n, __code next(...));
+    __code namecmp(Impl* fs, const char* s, const char* t, __code next(...));
+    __code dirlookup(struct inode* dp, char* name, uint* poff, __code next(...));
+    __code dirlink (Impl* fs, struct inode* dp, char* name, uint inum, __code next(...));
+    __code namei(Impl* fs, char* path, __code next(...));
+    __code nameiparent(Impl* fs, char* path, char* name, __code next(...));
+
+} fs;