Index: etc/defaults/rc.conf
===================================================================
RCS file: /home/ncvs/src/etc/defaults/rc.conf,v
retrieving revision 1.357
diff -u -r1.357 rc.conf
--- etc/defaults/rc.conf	2 Jun 2009 22:15:47 -0000	1.357
+++ etc/defaults/rc.conf	3 Jun 2009 20:18:15 -0000
@@ -83,6 +83,7 @@
 
 root_rw_mount="YES"	# Set to NO to inhibit remounting root read-write.
 fsck_y_enable="NO"	# Set to YES to do fsck -y if the initial preen fails.
+fsck_y_flags=""		# Additional flags for fsck -y
 background_fsck="YES"	# Attempt to run fsck in the background where possible.
 background_fsck_delay="60" # Time to wait (seconds) before starting the fsck.
 netfs_types="nfs:NFS nfs4:NFS4 smbfs:SMB portalfs:PORTAL nwfs:NWFS" # Net filesystems.
Index: etc/rc.d/fsck
===================================================================
RCS file: /home/ncvs/src/etc/rc.d/fsck,v
retrieving revision 1.13
diff -u -r1.13 fsck
--- etc/rc.d/fsck	23 Jun 2008 04:46:54 -0000	1.13
+++ etc/rc.d/fsck	3 Jun 2009 20:18:15 -0000
@@ -44,8 +44,8 @@
 			;;
 		8)
 			if checkyesno fsck_y_enable; then
-				echo "File system preen failed, trying fsck -y."
-				fsck -y
+				echo "File system preen failed, trying fsck -y ${fsck_y_flags}"
+				fsck -y ${fsck_y_flags}
 				case $? in
 				0)
 					;;
Index: sbin/fsck_msdosfs/main.c
===================================================================
RCS file: /home/ncvs/src/sbin/fsck_msdosfs/main.c,v
retrieving revision 1.15
diff -u -r1.15 main.c
--- sbin/fsck_msdosfs/main.c	10 Feb 2005 09:39:51 -0000	1.15
+++ sbin/fsck_msdosfs/main.c	3 Jun 2009 20:18:15 -0000
@@ -74,8 +74,10 @@
 	int ch;
 
 	skipclean = 1;
-	while ((ch = getopt(argc, argv, "fFnpy")) != -1) {
+	while ((ch = getopt(argc, argv, "CfFnpy")) != -1) {
 		switch (ch) {
+		case 'C': /* for fsck_ffs compatibility */
+			break;
 		case 'f':
 			skipclean = 0;
 			break;
Index: sbin/fsck_msdosfs/fsck_msdosfs.8
===================================================================
RCS file: /home/ncvs/src/sbin/fsck_msdosfs/fsck_msdosfs.8,v
retrieving revision 1.15
diff -u -r1.15 fsck_msdosfs.8
--- sbin/fsck_msdosfs/fsck_msdosfs.8	10 Feb 2005 09:39:51 -0000	1.15
+++ sbin/fsck_msdosfs/fsck_msdosfs.8	3 Jun 2009 20:18:15 -0000
@@ -32,7 +32,7 @@
 .\"
 .\" $FreeBSD: src/sbin/fsck_msdosfs/fsck_msdosfs.8,v 1.15 2005/02/10 09:39:51 ru Exp $
 .\"
-.Dd August 13, 1995
+.Dd June 4, 2009
 .Dt FSCK_MSDOSFS 8
 .Os
 .Sh NAME
@@ -41,10 +41,10 @@
 .Sh SYNOPSIS
 .Nm
 .Fl p
-.Op Fl f
+.Op Fl Cf
 .Ar filesystem ...
 .Nm
-.Op Fl ny
+.Op Fl Cny
 .Ar filesystem ...
 .Sh DESCRIPTION
 The
@@ -80,6 +80,10 @@
 .Pp
 The options are as follows:
 .Bl -tag -width indent
+.It Fl C
+Compatibility with the corresponding
+.Xr fsck 8
+option (skip check if clean), defined to no-op.
 .It Fl F
 Compatibility with the wrapper
 .Xr fsck 8