diff --git a/sbin/newfs/Makefile b/sbin/newfs/Makefile
index efbe7abfe492..9454e5301444 100644
--- a/sbin/newfs/Makefile
+++ b/sbin/newfs/Makefile
@@ -1,10 +1,13 @@
 #	@(#)Makefile	8.2 (Berkeley) 3/27/94
 # $FreeBSD$
 
+.PATH: ${.CURDIR}/../../sys/geom
+
 PROG=	newfs
 DPADD=	${LIBUFS}
 LDADD=	-lufs
-SRCS=	newfs.c mkfs.c
+SRCS=	newfs.c mkfs.c geom_bsd_enc.c
+
 WARNS?=	2
 MAN=	newfs.8
 
diff --git a/sbin/newfs/mkfs.c b/sbin/newfs/mkfs.c
index b3bbcbf3b351..072e528113f9 100644
--- a/sbin/newfs/mkfs.c
+++ b/sbin/newfs/mkfs.c
@@ -459,7 +459,7 @@ mkfs(struct partition *pp, char *fsys)
 	 * Wipe out old UFS1 superblock(s) if necessary.
 	 */
 	if (!Nflag && Oflag != 1) {
-		i = bread(&disk, SBLOCK_UFS1 / disk.d_bsize, chdummy, SBLOCKSIZE);
+		i = bread(&disk, part_ofs + SBLOCK_UFS1 / disk.d_bsize, chdummy, SBLOCKSIZE);
 		if (i == -1)
 			err(1, "can't read old UFS1 superblock: %s", disk.d_error);
 
@@ -872,7 +872,7 @@ alloc(int size, int mode)
 {
 	int i, d, blkno, frag;
 
-	bread(&disk, fsbtodb(&sblock, cgtod(&sblock, 0)), (char *)&acg,
+	bread(&disk, part_ofs + fsbtodb(&sblock, cgtod(&sblock, 0)), (char *)&acg,
 	    sblock.fs_cgsize);
 	if (acg.cg_magic != CG_MAGIC) {
 		printf("cg 0: bad magic number\n");
@@ -925,7 +925,7 @@ iput(union dinode *ip, ino_t ino)
 	int c;
 
 	c = ino_to_cg(&sblock, ino);
-	bread(&disk, fsbtodb(&sblock, cgtod(&sblock, 0)), (char *)&acg,
+	bread(&disk, part_ofs + fsbtodb(&sblock, cgtod(&sblock, 0)), (char *)&acg,
 	    sblock.fs_cgsize);
 	if (acg.cg_magic != CG_MAGIC) {
 		printf("cg 0: bad magic number\n");
@@ -942,7 +942,7 @@ iput(union dinode *ip, ino_t ino)
 		exit(32);
 	}
 	d = fsbtodb(&sblock, ino_to_fsba(&sblock, ino));
-	bread(&disk, d, (char *)iobuf, sblock.fs_bsize);
+	bread(&disk, part_ofs + d, (char *)iobuf, sblock.fs_bsize);
 	if (sblock.fs_magic == FS_UFS1_MAGIC)
 		((struct ufs1_dinode *)iobuf)[ino_to_fsbo(&sblock, ino)] =
 		    ip->dp1;
diff --git a/sbin/newfs/newfs.8 b/sbin/newfs/newfs.8
index 8771188f18a1..6dcb8592b9e1 100644
--- a/sbin/newfs/newfs.8
+++ b/sbin/newfs/newfs.8
@@ -52,6 +52,7 @@
 .Op Fl i Ar bytes
 .Op Fl m Ar free-space
 .Op Fl o Ar optimization
+.Op Fl p Ar partition
 .Op Fl r Ar reserved
 .Op Fl s Ar size
 .Ar special
@@ -201,6 +202,17 @@ the default is to optimize for
 See
 .Xr tunefs 8
 for more details on how to set this option.
+.It Fl p Ar partition
+The partition name (a..h) you want to use in case the underlying image
+is a file, so you don't have access to individual partitions through the
+filesystem.
+Can also be used with a device, e.g.
+.Nm
+.Fl p Ar f
+.Ar /dev/da1s3
+is equivalent to
+.Nm
+.Ar /dev/da1s3f .
 .It Fl r Ar reserved
 The size, in sectors, of reserved space
 at the end of the partition specified in
diff --git a/sbin/newfs/newfs.c b/sbin/newfs/newfs.c
index d5fb66d8346d..269707b5e43f 100644
--- a/sbin/newfs/newfs.c
+++ b/sbin/newfs/newfs.c
@@ -139,6 +139,9 @@ u_char	*volumelabel = NULL;	/* volume label for filesystem */
 struct uufsd disk;		/* libufs disk structure */
 
 static char	device[MAXPATHLEN];
+static u_char   bootarea[BBSIZE];
+static int	is_file;		/* work on a file, not a device */
+static char	*dkname;
 static char	*disktype;
 static int	unlabeled;
 
@@ -147,6 +150,18 @@ static struct disklabel *getdisklabel(char *s);
 static void rewritelabel(char *s, struct disklabel *lp);
 static void usage(void);
 
+ufs2_daddr_t part_ofs; /* partition offset in blocks, used with files */
+
+/*
+ * need to replace the library's bwrite so that sbwrite uses this one
+ */
+ssize_t
+bwrite(struct uufsd *disk, ufs2_daddr_t blockno, const void *data, size_t size)
+{
+	return pwrite(disk->d_fd, data, size,
+		(off_t)((part_ofs + blockno) * disk->d_bsize));
+}
+
 int
 main(int argc, char *argv[])
 {
@@ -158,7 +173,9 @@ main(int argc, char *argv[])
 	intmax_t reserved;
 	int ch, i;
 	off_t mediasize;
+	char part_name;		/* partition name, default to full disk */
 
+	part_name = 'c';
 	reserved = 0;
 	while ((ch = getopt(argc, argv,
 	    "EJL:NO:RS:T:UXa:b:c:d:e:f:g:h:i:lm:no:r:s:")) != -1)
@@ -276,6 +293,11 @@ main(int argc, char *argv[])
 			    *cp != '\0' || reserved < 0)
 				errx(1, "%s: bad reserved size", optarg);
 			break;
+		case 'p':
+			is_file = 1;
+			part_name = optarg[0];
+			break;
+
 		case 's':
 			errno = 0;
 			fssize = strtoimax(optarg, &cp, 0);
@@ -294,6 +316,8 @@ main(int argc, char *argv[])
 		usage();
 
 	special = argv[0];
+	if (!special[0])
+		err(1, "empty file/special name");
 	cp = strrchr(special, '/');
 	if (cp == 0) {
 		/*
@@ -303,7 +327,16 @@ main(int argc, char *argv[])
 		special = device;
 	}
 
-	if (ufs_disk_fillout_blank(&disk, special) == -1 ||
+	if (is_file) {
+		/* bypass ufs_disk_fillout_blank */
+		bzero( &disk, sizeof(disk));
+		disk.d_bsize = 1;
+		disk.d_name = special;
+		disk.d_fd = open(special, O_RDONLY);
+		if (disk.d_fd < 0 ||
+		    (!Nflag && ufs_disk_write(&disk) == -1))
+			errx(1, "%s: ", special);
+	} else if (ufs_disk_fillout_blank(&disk, special) == -1 ||
 	    (!Nflag && ufs_disk_write(&disk) == -1)) {
 		if (disk.d_error != NULL)
 			errx(1, "%s: %s", special, disk.d_error);
@@ -312,22 +345,30 @@ main(int argc, char *argv[])
 	}
 	if (fstat(disk.d_fd, &st) < 0)
 		err(1, "%s", special);
-	if ((st.st_mode & S_IFMT) != S_IFCHR)
-		errx(1, "%s: not a character-special device", special);
+	if ((st.st_mode & S_IFMT) != S_IFCHR) {
+		warn("%s: not a character-special device", special);
+		is_file = 1;	/* assume it is a file */
+		dkname = special;
+		if (sectorsize == 0)
+			sectorsize = 512;
+		mediasize = st.st_size;
+		/* set fssize from the partition */
+	} else {
+	    part_name = special[strlen(special) - 1];
+	    if ((part_name < 'a' || part_name > 'h') && !isdigit(part_name))
+		errx(1, "%s: can't figure out file system partition",
+				special);
 
-	if (sectorsize == 0)
+	    if (sectorsize == 0)
 		if (ioctl(disk.d_fd, DIOCGSECTORSIZE, &sectorsize) == -1)
-			sectorsize = 0;	/* back out on error for safety */
-	if (sectorsize && ioctl(disk.d_fd, DIOCGMEDIASIZE, &mediasize) != -1)
+		    sectorsize = 0;	/* back out on error for safety */
+	    if (sectorsize && ioctl(disk.d_fd, DIOCGMEDIASIZE, &mediasize) != -1)
 		getfssize(&fssize, special, mediasize / sectorsize, reserved);
+	}
 	pp = NULL;
 	lp = getdisklabel(special);
 	if (lp != NULL) {
-		cp = strchr(special, '\0');
-		cp--;
-		if ((*cp < 'a' || *cp > 'h') && !isdigit(*cp))
-			errx(1, "%s: can't figure out file system partition",
-			    special);
+		cp = &part_name;
 		if (isdigit(*cp))
 			pp = &lp->d_partitions[RAW_PART];
 		else
@@ -346,6 +387,8 @@ main(int argc, char *argv[])
 			fsize = pp->p_fsize;
 		if (bsize == 0)
 			bsize = pp->p_frag * pp->p_fsize;
+		if (is_file)
+			part_ofs = pp->p_offset;
 	}
 	if (sectorsize <= 0)
 		errx(1, "%s: no default sector size", special);
@@ -414,6 +457,19 @@ getdisklabel(char *s)
 	static struct disklabel lab;
 	struct disklabel *lp;
 
+	if (is_file) {
+		if (read(disk.d_fd, bootarea, BBSIZE) != BBSIZE)
+			err(4, "cannot read bootarea");
+		if (bsd_disklabel_le_dec(
+		    bootarea + (0 /* labeloffset */ +
+				1 /* labelsoffset */ * sectorsize),
+		    &lab, MAXPARTITIONS))
+			errx(1, "no valid label found");
+
+		lp = &lab;
+		return &lab;
+	}
+
 	if (ioctl(disk.d_fd, DIOCGDINFO, (char *)&lab) != -1)
 		return (&lab);
 	unlabeled++;
@@ -432,6 +488,14 @@ rewritelabel(char *s, struct disklabel *lp)
 		return;
 	lp->d_checksum = 0;
 	lp->d_checksum = dkcksum(lp);
+	if (is_file) {
+		bsd_disklabel_le_enc(bootarea + 0 /* labeloffset */ +
+			1 /* labelsoffset */ * sectorsize, lp);
+		lseek(disk.d_fd, 0, SEEK_SET);
+		if (write(disk.d_fd, bootarea, BBSIZE) != BBSIZE)
+			errx(1, "cannot write label");
+		return;
+	}
 	if (ioctl(disk.d_fd, DIOCWDINFO, (char *)lp) == -1)
 		warn("ioctl (WDINFO): %s: can't rewrite disk label", s);
 }
@@ -467,6 +531,7 @@ usage()
 	fprintf(stderr, "\t-n do not create .snap directory\n");
 	fprintf(stderr, "\t-m minimum free space %%\n");
 	fprintf(stderr, "\t-o optimization preference (`space' or `time')\n");
+	fprintf(stderr, "\t-p partition name (a..h)\n");
 	fprintf(stderr, "\t-r reserved sectors at the end of device\n");
 	fprintf(stderr, "\t-s file system size (sectors)\n");
 	exit(1);
diff --git a/sbin/newfs/newfs.h b/sbin/newfs/newfs.h
index 5c428c412ecf..0d7cb62379dc 100644
--- a/sbin/newfs/newfs.h
+++ b/sbin/newfs/newfs.h
@@ -70,4 +70,20 @@ extern int	avgfilesperdir;	/* expected number of files per directory */
 extern u_char	*volumelabel;	/* volume label for filesystem */
 extern struct uufsd disk;	/* libufs disk structure */
 
+/*
+ * To override a limitation in libufs, export the offset (in sectors) of the
+ * partition on the underlying media (file or disk). The value is used as
+ * an offset for all accesses to the media through bread(), which is only
+ * invoked directly in this program.
+ * For bwrite() we need a different approach, namely override the library
+ * version with one defined here. This is because bwrite() is called also
+ * by the library function sbwrite() which we cannot intercept nor want to
+ * rewrite. As a consequence, the internal version of bwrite() adds the
+ * partition offset itself when calling the underlying function, pwrite().
+ *
+ * XXX This info really ought to go into the struct uufsd, at which point
+ * we can remove the above hack.
+ */
+extern ufs2_daddr_t part_ofs;	/* partition offset in blocks */
+
 void mkfs (struct partition *, char *);