Index: head/sys/dev/md/md.c
===================================================================
--- head/sys/dev/md/md.c
+++ head/sys/dev/md/md.c
@@ -151,7 +151,6 @@
 #define	MDIOCATTACH_32	_IOC_NEWTYPE(MDIOCATTACH, struct md_ioctl32)
 #define	MDIOCDETACH_32	_IOC_NEWTYPE(MDIOCDETACH, struct md_ioctl32)
 #define	MDIOCQUERY_32	_IOC_NEWTYPE(MDIOCQUERY, struct md_ioctl32)
-#define	MDIOCLIST_32	_IOC_NEWTYPE(MDIOCLIST, struct md_ioctl32)
 #define	MDIOCRESIZE_32	_IOC_NEWTYPE(MDIOCRESIZE, struct md_ioctl32)
 #endif /* COMPAT_FREEBSD32 */
 
@@ -1876,48 +1875,6 @@
 	return (error);
 }
 
-static int
-kern_mdlist_locked(struct md_req *mdr)
-{
-	struct md_s *sc;
-	int i;
-
-	sx_assert(&md_sx, SA_XLOCKED);
-
-	/*
-	 * Write the number of md devices to mdr->md_units[0].
-	 * Write the unit number of the first (mdr->md_units_nitems - 2)
-	 * units to mdr->md_units[1::(mdr->md_units - 2)] and terminate the
-	 * list with -1.
-	 *
-	 * XXX: There is currently no mechanism to retrieve unit
-	 * numbers for more than (MDNPAD - 2) units.
-	 *
-	 * XXX: Due to the use of LIST_INSERT_HEAD in mdnew(), the
-	 * list of visible unit numbers not stable.
-	 */
-	i = 1;
-	LIST_FOREACH(sc, &md_softc_list, list) {
-		if (i < mdr->md_units_nitems - 1)
-			mdr->md_units[i] = sc->unit;
-		i++;
-	}
-	mdr->md_units[MIN(i, mdr->md_units_nitems - 1)] = -1;
-	mdr->md_units[0] = i - 1;
-	return (0);
-}
-
-static int
-kern_mdlist(struct md_req *mdr)
-{
-	int error;
-
-	sx_xlock(&md_sx);
-	error = kern_mdlist_locked(mdr);
-	sx_xunlock(&md_sx);
-	return (error);
-}
-
 /* Copy members that are not userspace pointers. */
 #define	MD_IOCTL2REQ(mdio, mdr) do {					\
 	(mdr)->md_unit = (mdio)->md_unit;				\
@@ -1958,8 +1915,7 @@
 	case MDIOCATTACH:
 	case MDIOCDETACH:
 	case MDIOCRESIZE:
-	case MDIOCQUERY:
-	case MDIOCLIST: {
+	case MDIOCQUERY: {
 		struct md_ioctl *mdio = (struct md_ioctl *)addr;
 		if (mdio->md_version != MDIOVERSION)
 			return (EINVAL);
@@ -1976,8 +1932,7 @@
 	case MDIOCATTACH_32:
 	case MDIOCDETACH_32:
 	case MDIOCRESIZE_32:
-	case MDIOCQUERY_32:
-	case MDIOCLIST_32: {
+	case MDIOCQUERY_32: {
 		struct md_ioctl32 *mdio = (struct md_ioctl32 *)addr;
 		if (mdio->md_version != MDIOVERSION)
 			return (EINVAL);
@@ -2018,12 +1973,6 @@
 	case MDIOCQUERY_32:
 #endif
 		error = kern_mdquery(&mdr);
-		break;
-	case MDIOCLIST:
-#ifdef COMPAT_FREEBSD32
-	case MDIOCLIST_32:
-#endif
-		error = kern_mdlist(&mdr);
 		break;
 	default:
 		error = ENOIOCTL;
Index: head/sys/sys/mdioctl.h
===================================================================
--- head/sys/sys/mdioctl.h
+++ head/sys/sys/mdioctl.h
@@ -64,7 +64,7 @@
 	int		md_fwheads;	/* firmware heads */
 	int		md_fwsectors;	/* firmware sectors */
 	char		*md_label;	/* label of the device */
-	int		md_pad[MDNPAD];	/* storage for MDIOCLIST */
+	int		md_pad[MDNPAD];	/* padding */
 };
 
 #define MD_NAME		"md"
@@ -81,7 +81,6 @@
 #define MDIOCATTACH	_IOWR('m', 0, struct md_ioctl)	/* attach disk */
 #define MDIOCDETACH	_IOWR('m', 1, struct md_ioctl)	/* detach disk */
 #define MDIOCQUERY	_IOWR('m', 2, struct md_ioctl)	/* query status */
-#define MDIOCLIST	_IOWR('m', 3, struct md_ioctl)	/* query status */
 #define MDIOCRESIZE	_IOWR('m', 4, struct md_ioctl)	/* resize disk */
 
 #define MD_CLUSTER	0x01	/* Don't cluster */