--- Net2/sys/mount.h	2018/04/24 18:03:58	1.1.1.1
+++ Net2/sys/mount.h	2018/04/24 18:10:37	1.1.1.2
@@ -73,11 +73,14 @@ struct statfs {
  * File system types.
  */
 #define	MOUNT_NONE	0
-#define	MOUNT_UFS	1
-#define	MOUNT_NFS	2
-#define	MOUNT_MFS	3
-#define	MOUNT_PC	4
-#define	MOUNT_MAXTYPE	4
+#define	MOUNT_UFS	1		/* UNIX "Fast" Filesystem */
+#define	MOUNT_NFS	2		/* Network Filesystem */
+#define	MOUNT_MFS	3		/* Memory Filesystem */
+#define	MOUNT_MSDOS	4		/* MSDOS Filesystem */
+#define MOUNT_ISOFS	5		/* iso9660 cdrom */
+#define MOUNT_FDESC	6		/* /dev/fd filesystem */
+#define MOUNT_KERNFS	7		/* kernel variable filesystem */
+#define	MOUNT_MAXTYPE	7
 
 /*
  * Structure per mounted file system.
@@ -105,6 +108,7 @@ struct mount {
 #define	MNT_NOEXEC	0x00000004	/* can't exec from filesystem */
 #define	MNT_NOSUID	0x00000008	/* don't honor setuid bits on fs */
 #define	MNT_NODEV	0x00000010	/* don't interpret special files */
+#define	MNT_UNION	0x00000020	/* union with underlying filesysem */
 
 /*
  * exported mount flags.
@@ -217,7 +221,7 @@ struct mfs_args {
 };
 #endif MFS
 
-#ifdef NFS
+#if defined(NFSSERVER) || defined(NFSCLIENT)
 /*
  * File Handle (32 bytes for version 2), variable up to 1024 for version 3
  */
@@ -258,7 +262,18 @@ struct nfs_args {
 #define	NFSMNT_SPONGY	0x0400	/* spongy mount (soft for stat and lookup) */
 #define	NFSMNT_COMPRESS	0x0800	/* Compress nfs rpc xdr */
 #define	NFSMNT_LOCKBITS	(NFSMNT_SCKLOCK | NFSMNT_WANTSCK)
-#endif NFS
+#endif /* defined(NFSSERVER || defined(NFSCLIENT) */
+
+#ifdef PCFS
+/*
+ *  Arguments to mount MSDOS filesystems.
+ */
+struct pcfs_args {
+	char *fspec;		/* blocks special holding the fs to mount */
+	int exflags;		/* mount flags				*/
+	uid_t exroot;		/* mapping for root uid			*/
+};
+#endif /* PCFS */
 
 #ifdef KERNEL
 /*