Index: head/sys/geom/geom_dev.c
===================================================================
--- head/sys/geom/geom_dev.c
+++ head/sys/geom/geom_dev.c
@@ -550,9 +550,6 @@
 		if (error == 0 && *(u_int *)data == 0)
 			error = ENOENT;
 		break;
-	case DIOCGFRONTSTUFF:
-		error = g_io_getattr("GEOM::frontstuff", cp, &i, data);
-		break;
 #ifdef COMPAT_FREEBSD11
 	case DIOCSKERNELDUMP_FREEBSD11:
 	    {
Index: head/sys/geom/geom_disk.c
===================================================================
--- head/sys/geom/geom_disk.c
+++ head/sys/geom/geom_disk.c
@@ -498,8 +498,6 @@
 			break;
 		else if (g_handleattr_int(bp, "GEOM::fwheads", dp->d_fwheads))
 			break;
-		else if (g_handleattr_off_t(bp, "GEOM::frontstuff", 0))
-			break;
 		else if (g_handleattr_str(bp, "GEOM::ident", dp->d_ident))
 			break;
 		else if (g_handleattr_str(bp, "GEOM::descr", dp->d_descr))
Index: head/sys/sys/disk.h
===================================================================
--- head/sys/sys/disk.h
+++ head/sys/sys/disk.h
@@ -64,14 +64,6 @@
 	 * core dumps.
 	 */
 
-#define	DIOCGFRONTSTUFF _IOR('d', 134, off_t)
-	/*
-	 * Many disk formats have some amount of space reserved at the
-	 * start of the disk to hold bootblocks, various disklabels and
-	 * similar stuff.  This ioctl returns the number of such bytes
-	 * which may apply to the device.
-	 */
-
 #define	DIOCGFLUSH _IO('d', 135)		/* Flush write cache */
 	/*
 	 * Flush write cache of the device.