--- mtools-3.9.9/mformat.c.supermount	2003-08-25 16:20:55.000000000 +0200
+++ mtools-3.9.9/mformat.c	2003-08-25 17:35:02.000000000 +0200
@@ -935,6 +935,24 @@
 		strcpy(name, getVoldName(dev, name));
 #endif
 
+		/* check if device can safely be written to,
+		 * check if supermount is used (only read access is checked
+		 * as this binary could be setuid root). */
+		if (!access(name, W_OK) &&
+		    !access("/proc/fs/supermount/subfs", R_OK)) {
+			FILE *fd;
+			/* gain root privileges to open supermount file */
+			seteuid(0);
+			setegid(0);
+			if ((fd = fopen("/proc/fs/supermount/subfs", "w"))) {
+				fprintf(fd, "%s release\n", name);
+				fclose(fd);
+			}
+			/* drop privileges given to release lock on floppy */
+			seteuid(getuid());
+			setegid(getgid());
+		}
+
 #ifdef USE_XDF
 		if(!format_xdf) {
 #endif