Index: head/sbin/mdmfs/mdmfs.8
===================================================================
--- head/sbin/mdmfs/mdmfs.8
+++ head/sbin/mdmfs/mdmfs.8
@@ -25,7 +25,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd March 7, 2016
+.Dd March 9, 2016
 .Dt MDMFS 8
 .Os
 .Sh NAME
@@ -36,7 +36,7 @@
 driver
 .Sh SYNOPSIS
 .Nm
-.Op Fl DLlMNnPStUX
+.Op Fl DLlMNnPStTUX
 .Op Fl a Ar maxcontig
 .Op Fl b Ar block-size
 .Op Fl c Ar blocks-per-cylinder-group
@@ -51,6 +51,7 @@
 .Op Fl o Ar mount-options
 .Op Fl p Ar permissions
 .Op Fl s Ar size
+.Op Fl T Ar fstype
 .Op Fl v Ar version
 .Op Fl w Ar user : Ns Ar group
 .Ar md-device
@@ -232,6 +233,16 @@
 .Xr md 4
 device supports the BIO_DELETE command, enabling the TRIM on created
 filesystem allows return of freed memory to the system pool.
+.It Fl T Ar fstype
+Specify a file system type for a vnode-backed memory disk.
+Any file system supported by
+.Xr mount 8
+command can be used.
+This option only makes sense if both
+.Fl F
+and
+.Fl P
+are specified.
 .It Fl U
 Enable soft-updates on the file system.
 This is the default, and is accepted only
@@ -294,7 +305,13 @@
 .Fl o
 option is passed to
 .Xr mount 8
-with the same letter.
+with the same letter;
+the
+.Fl T
+option is passed to
+.Xr mount 8
+as
+.Fl t .
 See the programs that the options are passed to for more information
 on their semantics.
 .Sh EXAMPLES
@@ -335,6 +352,10 @@
 using automatic device numbering:
 .Pp
 .Dl "mdmfs -P -F foo.img mds1a /tmp/"
+.Pp
+Mount a vnode-backed cd9660 file system using automatic device numbering:
+.Pp
+.Dl "mdmfs -T cd9660 -P -F foo.iso md /tmp"
 .Sh COMPATIBILITY
 The
 .Nm
Index: head/sbin/mdmfs/mdmfs.c
===================================================================
--- head/sbin/mdmfs/mdmfs.c
+++ head/sbin/mdmfs/mdmfs.c
@@ -129,7 +129,7 @@
 	}
 
 	while ((ch = getopt(argc, argv,
-	    "a:b:Cc:Dd:E:e:F:f:hi:LlMm:NnO:o:Pp:Ss:tUv:w:X")) != -1)
+	    "a:b:Cc:Dd:E:e:F:f:hi:LlMm:NnO:o:Pp:Ss:tT:Uv:w:X")) != -1)
 		switch (ch) {
 		case 'a':
 			argappend(&newfs_arg, "-a %s", optarg);
@@ -218,6 +218,9 @@
 		case 't':
 			argappend(&newfs_arg, "-t");
 			break;
+		case 'T':
+			argappend(&mount_arg, "-t %s", optarg);
+			break;
 		case 'U':
 			softdep = true;
 			break;