Index: head/sbin/mdconfig/mdconfig.8
===================================================================
--- head/sbin/mdconfig/mdconfig.8
+++ head/sbin/mdconfig/mdconfig.8
@@ -37,7 +37,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd October 10, 2015
+.Dd August 28, 2017
 .Dt MDCONFIG 8
 .Os
 .Sh NAME
@@ -55,6 +55,7 @@
 .Op Fl u Ar unit
 .Op Fl x Ar sectors/track
 .Op Fl y Ar heads/cylinder
+.Op Fl L Ar label
 .Nm
 .Fl d
 .Fl u Ar unit
@@ -189,6 +190,12 @@
 options can be used to specify a synthetic geometry.
 This is useful for constructing bootable images for later download to
 other devices.
+.It Fl L Ar label
+Associate a label (arbitrary string) with the new memory disk.
+The label can then be inspected with
+.Bd -literal -offset indent
+.Nm Fl l v
+.Ed
 .It Fl o Oo Cm no Oc Ns Ar option
 Set or reset options.
 .Bl -tag -width indent
Index: head/sbin/mdconfig/mdconfig.c
===================================================================
--- head/sbin/mdconfig/mdconfig.c
+++ head/sbin/mdconfig/mdconfig.c
@@ -79,7 +79,7 @@
 
 	fprintf(stderr,
 "usage: mdconfig -a -t type [-n] [-o [no]option] ... [-f file]\n"
-"                [-s size] [-S sectorsize] [-u unit]\n"
+"                [-s size] [-S sectorsize] [-u unit] [-L label]\n"
 "                [-x sectors/track] [-y heads/cylinder]\n"
 "       mdconfig -d -u unit [-o [no]force]\n"
 "       mdconfig -r -u unit -s size [-o [no]force]\n"
@@ -102,15 +102,17 @@
 
 	bzero(&mdio, sizeof(mdio));
 	mdio.md_file = malloc(PATH_MAX);
-	if (mdio.md_file == NULL)
+	mdio.md_label = malloc(PATH_MAX);
+	if (mdio.md_file == NULL || mdio.md_label == NULL)
 		err(1, "could not allocate memory");
 	vflag = 0;
 	bzero(mdio.md_file, PATH_MAX);
+	bzero(mdio.md_label, PATH_MAX);
 
 	if (argc == 1)
 		usage();
 
-	while ((ch = getopt(argc, argv, "ab:df:lno:rs:S:t:u:vx:y:")) != -1) {
+	while ((ch = getopt(argc, argv, "ab:df:lno:rs:S:t:u:vx:y:L:")) != -1) {
 		switch (ch) {
 		case 'a':
 			if (action != UNSET && action != ATTACH)
@@ -243,6 +245,9 @@
 		case 'y':
 			mdio.md_fwheads = strtoul(optarg, &p, 0);
 			break;
+		case 'L':
+			strlcpy(mdio.md_label, optarg, PATH_MAX);
+			break;
 		default:
 			usage();
 		}
@@ -422,7 +427,8 @@
 	struct gclass *gcl;
 	void *sq;
 	int retcode, ffound, ufound;
-	char *type, *file, *length;
+	char *length;
+	const char *type, *file, *label;
 
 	type = file = length = NULL;
 
@@ -477,10 +483,14 @@
 				printf("\t%s\t", type);
 				if (length != NULL)
 					md_prthumanval(length);
-				if (file != NULL) {
-					printf("\t%s", file);
-					file = NULL;
-				}
+				if (file == NULL)
+					file = "-";
+				printf("\t%s", file);
+				file = NULL;
+				label = geom_config_get(gc, "label");
+				if (label == NULL)
+					label = "";
+				printf("\t%s", label);
 			}
 			opt |= OPT_DONE;
 			if ((opt & OPT_LIST) && !(opt & OPT_VERBOSE))
Index: head/sys/dev/md/md.c
===================================================================
--- head/sys/dev/md/md.c
+++ head/sys/dev/md/md.c
@@ -226,6 +226,7 @@
 	/* MD_VNODE related fields */
 	struct vnode *vnode;
 	char file[PATH_MAX];
+	char label[PATH_MAX];
 	struct ucred *cred;
 
 	/* MD_SWAP related fields */
@@ -1645,6 +1646,11 @@
 		}
 		if (sc == NULL)
 			return (error);
+		if (mdio->md_label != NULL)
+			error = copyinstr(mdio->md_label, sc->label,
+			    sizeof(sc->label), NULL);
+		if (error != 0)
+			goto err_after_new;
 		if (mdio->md_options & MD_AUTOUNIT)
 			mdio->md_unit = sc->unit;
 		sc->mediasize = mdio->md_mediasize;
@@ -1676,6 +1682,7 @@
 			error = mdcreate_null(sc, mdio, td);
 			break;
 		}
+err_after_new:
 		if (error != 0) {
 			mddestroy(sc, td);
 			return (error);
@@ -1721,6 +1728,11 @@
 		mdio->md_options = sc->flags;
 		mdio->md_mediasize = sc->mediasize;
 		mdio->md_sectorsize = sc->sectorsize;
+		error = 0;
+		if (mdio->md_label != NULL) {
+			error = copyout(sc->label, mdio->md_label,
+			    strlen(sc->label) + 1);
+		}
 		if (sc->type == MD_VNODE ||
 		    (sc->type == MD_PRELOAD && mdio->md_file != NULL))
 			error = copyout(sc->file, mdio->md_file,
@@ -1873,6 +1885,7 @@
 			if ((mp->type == MD_VNODE && mp->vnode != NULL) ||
 			    (mp->type == MD_PRELOAD && mp->file[0] != '\0'))
 				sbuf_printf(sb, " file %s", mp->file);
+			sbuf_printf(sb, " label %s", mp->label);
 		} else {
 			sbuf_printf(sb, "%s<unit>%d</unit>\n", indent,
 			    mp->unit);
@@ -1897,6 +1910,9 @@
 				g_conf_printf_escaped(sb, "%s", mp->file);
 				sbuf_printf(sb, "</file>\n");
 			}
+			sbuf_printf(sb, "%s<label>", indent);
+			g_conf_printf_escaped(sb, "%s", mp->label);
+			sbuf_printf(sb, "</label>\n");
 		}
 	}
 }
Index: head/sys/sys/mdioctl.h
===================================================================
--- head/sys/sys/mdioctl.h
+++ head/sys/sys/mdioctl.h
@@ -49,7 +49,7 @@
  * Ioctl definitions for memory disk pseudo-device.
  */
 
-#define MDNPAD		97
+#define MDNPAD		96
 struct md_ioctl {
 	unsigned	md_version;	/* Structure layout version */
 	unsigned	md_unit;	/* unit number */
@@ -61,6 +61,7 @@
 	u_int64_t	md_base;	/* base address */
 	int		md_fwheads;	/* firmware heads */
 	int		md_fwsectors;	/* firmware sectors */
+	char		*md_label;	/* label of the device */
 	int		md_pad[MDNPAD];	/* padding for future ideas */
 };