shuffle and tweak for formatting.

pdf has very good page breaks now.
would be a good copy for fall 2009.

file.h

@@ -7,3 +7,35 @@ struct file {
   struct inode *ip;
   uint off;
 };
+
+
+// in-core file system types
+
+struct inode {
+  uint dev;           // Device number
+  uint inum;          // Inode number
+  int ref;            // Reference count
+  int flags;          // I_BUSY, I_VALID
+
+  short type;         // copy of disk inode
+  short major;
+  short minor;
+  short nlink;
+  uint size;
+  uint addrs[NDIRECT+1];
+};
+
+#define I_BUSY 0x1
+#define I_VALID 0x2
+
+
+// device implementations
+
+struct devsw {
+  int (*read)(struct inode*, char*, int);
+  int (*write)(struct inode*, char*, int);
+};
+
+extern struct devsw devsw[];
+
+#define CONSOLE 1