Introduce mdmfs(8), a wrapper around mdconfig(8), disklabel(8),

newfs(8), and mount(8) that mimics the command line option set of the
deprecated mount_mfs(8).

Approved by:	jkh, phk, -hackers

4 files changed, 930 insertions, 0 deletions

diff --git a/sbin/mdmfs/Makefile b/sbin/mdmfs/Makefile
new file mode 100644
index 0000000..afa13e8
--- /dev/null
+++ b/sbin/mdmfs/Makefile
@@ -0,0 +1,7 @@
+# $FreeBSD$
+
+PROG=		mdmfs
+MAN=		mdmfs.8
+WARNS?=		2
+
+.include <bsd.prog.mk>
diff --git a/sbin/mdmfs/mdmfs.8 b/sbin/mdmfs/mdmfs.8
new file mode 100644
index 0000000..f5b6694
--- /dev/null
+++ b/sbin/mdmfs/mdmfs.8
@@ -0,0 +1,262 @@
+.\"
+.\" Copyright (c) 2001 Dima Dorfman <dd@FreeBSD.org>
+.\" All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\" $FreeBSD$
+.\"
+.Dd May 26, 2001
+.Dt MDMFS 8
+.Os
+.Sh NAME
+.Nm mdmfs
+.Nd configure and mount an in-memory filesystem using the
+.Xr md 4
+driver
+.Sh SYNOPSIS
+.Nm
+.Op Fl DLMNSX
+.Op Fl a Ar maxcontig
+.Op Fl b Ar block-size
+.Op Fl c Ar cylinders
+.Op Fl d Ar rotdelay
+.Op Fl e Ar maxbpg
+.Op Fl F Ar file
+.Op Fl f Ar frag-size
+.Op Fl i Ar bytes
+.Op Fl m Ar percent-free
+.Op Fl n Ar rotational-positions
+.Op Fl O Ar optimization
+.Op Fl o Ar mount-options
+.Op Fl p Ar permissions
+.Op Fl s Ar size
+.Op Fl w Ar user Ns | Ns Ar group
+.Ar md-device
+.Ar mount-point
+.Sh DESCRIPTION
+The
+.Nm
+program is designed to be a work-alike and look-alike of the deprecated
+.Xr mount_mfs 8 .
+The end result is essentially the same,
+but is accomplished in a completely different way.
+.Nm
+configures an
+.Xr md 4
+disk using
+.Xr mdconfig 8 ,
+labels it using
+.Xr disklabel 8 ,
+puts a UFS filesystem on it using
+.Xr newfs 8 ,
+and mounts it using
+.Xr mount 8 .
+All the command line options are passed to the appropriate program
+at the appropriate stage in order to achieve the desired effect.
+.Pp
+By default,
+.Nm
+creates a swap-based
+.Pq Dv MD_SWAP
+disk with soft-updates enabled
+and mounts it on
+.Ar mount-point .
+It uses the
+.Xr md 4
+device specified by
+.Ar md-device .
+If
+.Ar md-device
+is
+.Ql md
+(no unit number),
+it will use
+.Xr md 4 Ns 's
+auto-unit feature to automatically select an unused device.
+Unless otherwise specified with one of the options below,
+it uses the default arguments to all the helper programs.
+.Pp
+The following options are available.
+Where possible,
+the option letter matches the one used by
+.Xr mount_mfs 8
+for the same thing.
+.Bl -tag -width Ds
+.It Fl a Ar maxcontig
+Specify the maximum number of contiguous blocks that will be laid
+out before forcing a rotational delay
+(see the
+.Fl d
+option).
+.It Fl b Ar block-size
+The block size of the filesystem, in bytes.
+.It Fl c Ar cylinders
+The number of cylinders per cylinder group in the filesystem.
+.It Fl D
+If not using auto-unit,
+don't run
+.Xr mdconfig 8
+to try to detach the unit before attaching it.
+.It Fl d Ar rotdelay
+Specify the mininum time in milliseconds required to initiate another
+disk transfer on the same cylinder.
+Modern disks with read/write-behind achieve higher performance without
+this feature,
+so it is best to leave it at 0 milliseconds.
+.It Fl e Ar maxbpg
+Indicate the maximum number of blocks any single file can allocate
+out of a cylinder group before it is forced to begin allocating
+blocks from another cylinder group.
+.It Fl F Ar file
+Create a vnode-backed
+.Pq Dv MD_VNODE
+memory disk backed by
+.Ar file .
+.It Fl f Ar frag-size
+The fragment size of the filesystem in bytes.
+.It Fl i Ar bytes
+Number of bytes per inode.
+.It Fl L
+Show the output of the helper programs.
+By default,
+it is sent to
+.Pa /dev/null .
+.It Fl M
+Create a
+.Xr malloc 9
+backed disk
+.Pq Dv MD_MALLOC
+instead of a swap-backed disk.
+.It Fl m Ar percent-free
+The percentage of space reserved for the superuser.
+.It Fl N
+Don't actually run the helper programs.
+This is most useful in conjunction with
+.Fl X .
+.It Fl n Ar rotational-positions
+The default number of rotational positions to distinguish.
+.It Fl O Ar optimization
+Select the optimization preference;
+valid choices are
+.Ar space
+and
+.Ar time ,
+which will optimize for minimum space fragmentation and
+minimum time spent allocating blocks,
+respectively.
+.It Fl o Ar mount-options
+Specify the mount options with which to mount the filesystem.
+See
+.Xr mount 8
+for more information.
+.It Fl p Ar permissions
+Set the file (directory) permissions of the mount point
+.Ar mount-point
+to
+.Ar permissions .
+.It Fl S
+Don't enable soft-updates on the filesystem.
+.It Fl s Ar size
+Specify the size of the disk to create.
+This only makes sense if
+.Fl F
+is
+.Em not
+specified.
+That is,
+this will work for the default swap-backed
+.Pq Dv MD_SWAP
+disks,
+and the optional
+.Pq Fl M
+.Xr malloc 9
+backed disks
+.Pq Dv MD_MALLOC .
+.It Fl w Ar user Ns | Ns Ar group
+Set the owner user and group to
+.Ar user
+and
+.Ar group ,
+respectively.
+The arguments have the same semantics as with
+.Xr chown 8 ,
+but specifying just a user or just a group is not supported.
+.El
+.Pp
+The
+.Fl F
+and
+.Fl s
+options are passed to
+.Xr mdconfig 8
+as
+.Fl f
+and
+.Fl s ,
+respectively.
+The
+.Fl a ,
+.Fl b ,
+.Fl c ,
+.Fl d ,
+.Fl e ,
+.Fl f ,
+.Fl i ,
+.FL m
+and
+.Fl n
+options are passed to
+.Xr newfs 8
+with the same letter;
+the
+.Fl O
+option is passed to
+.Xr newfs 8
+as
+.Fl o .
+The
+.Fl o
+option is passed to
+.Xr mount 8
+with the same letter.
+See the programs that the options are passed to for more information
+on their semantics.
+.Sh EXAMPLES
+Create and mount a 32 megabyte swap-backed filesystem on
+.Pa /tmp :
+.Pp
+.Dl mdmfs -s 32m md /tmp
+.Pp
+Create and mount a 16 megabyte malloc-backed filesystem on
+.Pa /tmp
+using the
+.Pa /dev/md1
+device;
+furthermore,
+don't use soft-updates it and mount it
+.Cm async :
+.Pp
+.Dl mdmfs -M -S -o async -s 16m md1 /tmp
+.Sh AUTHOR
+.An Dima Dorfman
+.Aq dd@FreeBSD.org
diff --git a/sbin/mdmfs/mdmfs.c b/sbin/mdmfs/mdmfs.c
new file mode 100644
index 0000000..2debcea
--- /dev/null
+++ b/sbin/mdmfs/mdmfs.c
@@ -0,0 +1,651 @@
+/*
+ * Copyright (c) 2001 Dima Dorfman <dd@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * mdmfs (md/MFS) is a wrapper around mdconfig(8), disklabel(8),
+ * newfs(8), and mount(8) that mimics the command line option set of
+ * the deprecated mount_mfs(8).
+ */
+
+#ifndef lint
+static const char rcsid[] =
+  "$FreeBSD$";
+#endif /* not lint */
+
+#include <sys/param.h>
+#include <sys/mdioctl.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+
+#include <assert.h>
+#include <err.h>
+#include <fcntl.h>
+#include <grp.h>
+#include <paths.h>
+#include <pwd.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "pathnames.h"
+
+typedef enum { false, true } bool;
+
+struct mtpt_info {
+	uid_t		 mi_uid;
+	bool		 mi_have_uid;
+	gid_t		 mi_gid;
+	bool		 mi_have_gid;
+	mode_t		 mi_mode;
+	bool		 mi_have_mode;
+};
+
+static	bool debug;		/* Emit debugging information? */
+static	bool loudsubs;		/* Suppress output from helper programs? */
+static	bool norun;		/* Actually run the helper programs? */
+static	int unit;      		/* The unit we're working with. */
+static	const char *mdname;	/* Name of memory disk device (e.g., "md"). */
+static	size_t mdnamelen;	/* Length of mdname. */
+
+static void	 argappend(char **, const char *, ...);
+static void	 debugprintf(const char *, ...);
+static void	 do_disklabel(void);
+static void	 do_mdconfig_attach(const char *, const enum md_types);
+static void	 do_mdconfig_attach_au(const char *, const enum md_types);
+static void	 do_mdconfig_detach(void);
+static void	 do_mount(const char *, const char *);
+static void	 do_mtptsetup(const char *, struct mtpt_info *);
+static void	 do_newfs(const char *);
+static void	 extract_ugid(const char *, struct mtpt_info *);
+static int	 run(int *, const char *, ...);
+static void	 usage(void);
+
+int
+main(int ac, char **av)
+{
+	struct mtpt_info mi;		/* Mountpoint info. */
+	char *mdconfig_arg, *newfs_arg,	/* Args to helper programs. */
+	    *mount_arg;
+	enum md_types mdtype;		/* The type of our memory disk. */
+	bool have_mdtype;
+	bool detach, softdep, autounit;
+	char *mtpoint, *unitstr;
+	char ch, *p;
+
+	/* Misc. initialization. */
+	(void)memset(&mi, '\0', sizeof(mi));
+	detach = true;
+	softdep = true;
+	autounit = false;
+	have_mdtype = false;
+	mdname = MD_NAME;
+	mdnamelen = strlen(mdname);
+	/*
+	 * Can't set these to NULL.  They may be passed to the
+	 * respective programs without modification.  I.e., we may not
+	 * receive any command-line options which will caused them to
+	 * be modified.
+	 */
+	mdconfig_arg = strdup("");
+	newfs_arg = strdup("");
+	mount_arg = strdup("");
+
+	while ((ch = getopt(ac, av,
+	    "a:b:c:Dd:e:F:f:hi:LMm:Nn:O:o:p:Ss:t:w:X")) != -1)
+		switch (ch) {
+		case 'a':
+			argappend(&newfs_arg, "-a %s", optarg);
+			break;
+		case 'b':
+			argappend(&newfs_arg, "-b %s", optarg);
+			break;
+		case 'c':
+			argappend(&newfs_arg, "-c %s", optarg);
+			break;
+		case 'D':
+			detach = false;
+			break;
+		case 'd':
+			argappend(&newfs_arg, "-d %s", optarg);
+			break;
+		case 'e':
+			argappend(&newfs_arg, "-e %s", optarg);
+			break;
+		case 'F':
+			if (have_mdtype)
+				usage();
+			mdtype = MD_VNODE;
+			have_mdtype = true;
+			argappend(&mdconfig_arg, "-f %s", optarg);
+			break;
+		case 'f':
+			argappend(&newfs_arg, "-f %s", optarg);
+			break;
+		case 'h':
+			usage();
+			break;
+		case 'i':
+			argappend(&newfs_arg, "-i %s", optarg);
+			break;
+		case 'L':
+			loudsubs = true;
+			break;
+		case 'M':
+			if (have_mdtype)
+				usage();
+			mdtype = MD_MALLOC;
+			have_mdtype = true;
+			break;
+		case 'm':
+			argappend(&newfs_arg, "-m %s", optarg);
+			break;
+		case 'N':
+			norun = true;
+			break;
+		case 'n':
+			argappend(&newfs_arg, "-n %s", optarg);
+			break;
+		case 'O':
+			argappend(&newfs_arg, "-o %s", optarg);
+			break;
+		case 'o':
+			argappend(&mount_arg, "-o %s", optarg);
+			break;
+		case 'p':
+			if (*optarg >= '0' && *optarg <= '7')
+				mi.mi_mode = strtol(optarg, NULL, 8);
+			if ((mi.mi_mode & ~07777) != 0)
+				usage();
+			mi.mi_have_mode = true;
+			break;
+		case 'S':
+			softdep = false;
+			break;
+		case 's':
+			argappend(&mdconfig_arg, "-s %s", optarg);
+			break;
+		case 'w':
+			extract_ugid(optarg, &mi);
+			break;
+		case 'X':
+			debug = true;
+			break;
+		default:
+			usage();
+		}
+	ac -= optind;
+	av += optind;
+	if (ac < 2)
+		usage();
+
+	/* Derive 'unit' (global). */
+	unitstr = av[0];
+	if (strncmp(unitstr, "/dev/", 5) == 0)
+		unitstr += 5;
+	if (strncmp(unitstr, mdname, mdnamelen) == 0)
+		unitstr += mdnamelen;
+	if (*unitstr == '\0') {
+		autounit = true;
+		unit = -1;
+	} else {
+		unit = strtoul(unitstr, &p, 10);
+		if ((unsigned)unit == ULONG_MAX || *p != '\0')
+			errx(1, "bad device unit: %s", unitstr);
+	}
+
+	mtpoint = av[1];
+	if (!have_mdtype)
+		mdtype = MD_SWAP;
+	if (softdep)
+		argappend(&newfs_arg, "-U");
+
+	/* Do the work. */
+	if (detach && !autounit)
+		do_mdconfig_detach();
+	if (autounit)
+		do_mdconfig_attach_au(mdconfig_arg, mdtype);
+	else
+		do_mdconfig_attach(mdconfig_arg, mdtype);
+	do_disklabel();
+	do_newfs(newfs_arg);
+	do_mount(mount_arg, mtpoint);
+	do_mtptsetup(mtpoint, &mi);
+
+	return (0);
+}
+
+/*
+ * Append the expansion of 'fmt' to the buffer pointed to by '*dstp';
+ * reallocate as required.
+ */
+static void
+argappend(char **dstp, const char *fmt, ...)
+{
+	char *old, *new;
+	va_list ap;
+	
+	old = *dstp;
+	assert(old != NULL);
+
+	va_start(ap, fmt);
+	if (vasprintf(&new, fmt,ap) == -1)
+		errx(1, "vasprintf");
+	va_end(ap);
+
+	*dstp = new;
+	if (asprintf(&new, "%s %s", old, new) == -1)
+		errx(1, "asprintf");
+	free(*dstp);
+	free(old);
+
+	*dstp = new;
+}
+
+/*
+ * If run-time debugging is enabled, print the expansion of 'fmt'.
+ * Otherwise, do nothing.
+ */
+static void
+debugprintf(const char *fmt, ...)
+{
+	va_list ap;
+
+	if (!debug)
+		return;
+	fprintf(stderr, "DEBUG: ");
+	va_start(ap, fmt);
+	vfprintf(stderr, fmt, ap);
+	va_end(ap);
+	fprintf(stderr, "\n");
+	fflush(stderr);
+}
+
+/*
+ * Label the memory disk.
+ */
+static void
+do_disklabel(void)
+{
+	int rv;
+
+	rv = run(NULL, "%s -r -w %s%d auto", PATH_DISKLABEL, mdname, unit);
+	if (rv)
+		errx(1, "disklabel exited with error code %d", rv);
+}
+
+/*
+ * Attach a memory disk with a known unit.
+ */
+static void
+do_mdconfig_attach(const char *args, const enum md_types mdtype)
+{
+	int rv;
+	const char *ta;		/* Type arg. */
+
+	switch (mdtype) {
+	case MD_SWAP:
+		ta = "-t swap";
+		break;
+	case MD_VNODE:
+		ta = "-t vnode";
+		break;
+	case MD_MALLOC:
+		ta = "-t malloc";
+		break;
+	default:
+		abort();
+	}
+	rv = run(NULL, "%s -a %s%s -u %s%d", PATH_MDCONFIG, ta, args,
+	    mdname, unit);
+	if (rv)
+		errx(1, "mdconfig (attach) exited with error code %d", rv);
+}
+
+/*
+ * Attach a memory disk with an unknown unit; use autounit.
+ */
+static void
+do_mdconfig_attach_au(const char *args, const enum md_types mdtype)
+{
+	const char *ta;		/* Type arg. */
+	char *linep, *linebuf; 	/* Line pointer, line buffer. */
+	int fd;			/* Standard output of mdconfig invocation. */
+	FILE *sfd;
+	int rv;
+	char *p;
+	size_t linelen;
+
+	switch (mdtype) {
+	case MD_SWAP:
+		ta = "-t swap";
+		break;
+	case MD_VNODE:
+		ta = "-t vnode";
+		break;
+	case MD_MALLOC:
+		ta = "-t malloc";
+		break;
+	default:
+		abort();
+	}
+	rv = run(&fd, "%s -a %s%s", PATH_MDCONFIG, ta, args);
+	if (rv)
+		errx(1, "mdconfig (attach) exited with error code %d", rv);
+
+	/* Receive the unit number. */
+	if (norun) {	/* Since we didn't run, we can't read.  Fake it. */
+		unit = -1;
+		return;
+	}
+	sfd = fdopen(fd, "r");
+	if (sfd == NULL)
+		err(1, "fdopen");
+	linep = fgetln(sfd, &linelen);
+	if (linep == NULL && linelen < mdnamelen + 1)
+		errx(1, "unexpected output from mdconfig (attach)");
+	/* If the output format changes, we want to know about it. */
+	assert(strncmp(linep, mdname, mdnamelen) == 0);
+	linebuf = malloc(linelen - mdnamelen + 1);
+	assert(linebuf != NULL);
+	/* Can't use strlcpy because linep is not NULL-terminated. */
+	strncpy(linebuf, linep + mdnamelen, linelen);
+	linebuf[linelen] = '\0';
+	unit = strtoul(linebuf, &p, 10);
+	if ((unsigned)unit == ULONG_MAX || *p != '\n')
+		errx(1, "unexpected output from mdconfig (attach)");
+
+	fclose(sfd);
+	close(fd);
+}
+
+/*
+ * Detach a memory disk.
+ */
+static void
+do_mdconfig_detach(void)
+{
+	int rv;
+
+	rv = run(NULL, "%s -d -u %s%d", PATH_MDCONFIG, mdname, unit);
+	if (rv && debug)	/* This is allowed to fail. */
+		warnx("mdconfig (detach) exited with error code %d (ignored)",
+		      rv);
+}
+
+/*
+ * Mount the configured memory disk.
+ */
+static void
+do_mount(const char *args, const char *mtpoint)
+{
+	int rv;
+
+	rv = run(NULL, "%s%s /dev/%s%dc %s", PATH_MOUNT, args,
+	    mdname, unit, mtpoint);
+	if (rv)
+		errx(1, "mount exited with error code %d", rv);
+}
+
+/*
+ * Various configuration of the mountpoint.  Mostly, enact 'mip'.
+ */
+static void
+do_mtptsetup(const char *mtpoint, struct mtpt_info *mip)
+{
+
+	if (mip->mi_have_mode) {
+		debugprintf("changing mode of %s to %o.", mtpoint,
+		    mip->mi_mode);
+		if (!norun)
+			if (chmod(mtpoint, mip->mi_mode) == -1)
+				err(1, "chmod: %s", mtpoint);
+	}
+	/*
+	 * We have to do these separately because the user may have
+	 * only specified one of them.
+	 */
+	if (mip->mi_have_uid) {
+		debugprintf("changing owner (user) or %s to %u.", mtpoint,
+		    mip->mi_uid);
+		if (!norun)
+			if (chown(mtpoint, mip->mi_uid, -1) == -1)
+				err(1, "chown %s to %u (user)", mtpoint,
+				    mip->mi_uid);
+	}
+	if (mip->mi_have_gid) {
+		debugprintf("changing owner (group) or %s to %u.", mtpoint,
+		    mip->mi_gid);
+		if (!norun)
+			if (chown(mtpoint, -1, mip->mi_gid) == -1)
+				err(1, "chown %s to %u (group)", mtpoint,
+				    mip->mi_gid);
+	}
+}
+
+/*
+ * Put a filesystem on the memory disk.
+ */
+static void
+do_newfs(const char *args)
+{
+	int rv;
+
+	rv = run(NULL, "%s%s /dev/%s%dc", PATH_NEWFS, args, mdname, unit);
+	if (rv)
+		errx(1, "newfs exited with error code %d", rv);
+}
+
+/*
+ * 'str' should be a user and group name similar to the last argument
+ * to chown(1); i.e., a user, followed by a colon, followed by a
+ * group.  The user and group in 'str' may be either a [ug]id or a
+ * name.  Upon return, the uid and gid fields in 'mip' will contain
+ * the uid and gid of the user and group name in 'str', respectively.
+ *
+ * In other words, this derives a user and group id from a string
+ * formatted like the last argument to chown(1).
+ */
+static void
+extract_ugid(const char *str, struct mtpt_info *mip)
+{
+	char *ug;			/* Writable 'str'. */
+	char *user, *group;		/* Result of extracton. */
+	size_t strl;			/* Length of 'str' incl. NULL. */
+	struct passwd *pw;
+	struct group *gr;
+	char *p;
+	uid_t *uid;
+	gid_t *gid;
+	size_t rv;
+
+	uid = &mip->mi_uid;
+	gid = &mip->mi_gid;
+	mip->mi_have_uid = mip->mi_have_gid = false;
+
+	/* Extract the user and group from 'str'.  Format above. */
+	strl = strlen(str) + 1;
+	ug = malloc(strl);
+	assert(ug != NULL);
+	rv = strlcpy(ug, str, strl);
+	if (rv >= strl)
+		errx(1, "-w word too long (%d >= %d)", rv, strl);
+	group = ug;
+	user = strsep(&group, ":");
+	if (user == NULL || group == NULL || *user == '\0' || *group == '\0')
+		usage();
+
+	/* Derive uid. */
+	*uid = strtoul(user, &p, 10);
+	if ((unsigned)*uid == ULONG_MAX)
+		usage();
+	if (*p != '\0') {
+		pw = getpwnam(user);
+		if (pw == NULL)
+			errx(1, "invalid user: %s", user);
+		*uid = pw->pw_uid;
+		mip->mi_have_uid = true;
+	}
+
+	/* Derive gid. */
+	*gid = strtoul(group, &p, 10);
+	if ((unsigned)*gid == ULONG_MAX)
+		usage();
+	if (*p != '\0') {
+		gr = getgrnam(group);
+		if (gr == NULL)
+			errx(1, "invalid group: %s", group);
+		*gid = gr->gr_gid;
+		mip->mi_have_gid = true;
+	}
+
+	free(ug);
+	/*
+	 * At this point we don't support only a username or only a
+	 * group name.  do_mtptsetup already does, so when this
+	 * feature is desired, this is the only routine that needs to
+	 * be changed.
+	 */
+	assert(mip->mi_have_uid);
+	assert(mip->mi_have_gid);
+}
+
+/*
+ * Run a process with command name and arguments pointed to by the
+ * formatted string 'cmdline'.  Since system(3) is not used, the first
+ * space-delimited token of 'cmdline' must be the full pathname of the
+ * program to run.  The return value is the return code of the process
+ * spawned.  If 'ofd' is non-NULL, it is set to the standard output of
+ * the program spawned (i.e., you can read from ofd and get the output
+ * of the program).
+ */
+static int
+run(int *ofd, const char *cmdline, ...)
+{
+	char **av, **avp;		/* Result of splitting 'cmd'. */
+	int ac;
+	char *cmd;			/* Expansion of 'cmdline'. */
+	int pid, status;		/* Child info. */
+	int pfd[2];			/* Pipe to the child. */
+	int nfd;			/* Null (/dev/null) file descriptor. */
+	bool dup2dn;			/* Dup /dev/null to stdout? */
+	va_list ap;
+	char *p;
+	int rv, i;
+
+	dup2dn = true;
+	va_start(ap, cmdline);
+	rv = vasprintf(&cmd, cmdline, ap);
+	if (rv == -1)
+		err(1, "vasprintf");
+	va_end(ap);
+
+	/* Split up 'cmd' into 'av' for use with execve. */
+	for (ac = 1, p = cmd; (p = strchr(p, ' ')) != NULL; p++)
+		ac++;		/* 'ac' generation loop. */
+	av = (char **)malloc(sizeof(*av) * (ac + 1));
+	assert(av != NULL);
+	for (p = cmd, avp = av; (*avp = strsep(&p, " ")) != NULL;)
+		if (**av != '\0')
+			if (++avp >= &av[ac]) {
+				*avp = NULL;
+				break;
+			}
+	assert(*av);
+
+	/* Make sure the above loop works as expected. */
+	if (debug) {
+		/*
+		 * We can't, but should, use debugprintf here.  First,
+		 * it appends a trailing newline to the output, and
+		 * second it prepends "DEBUG: " to the output.  The
+		 * former is a problem for this would-be first call,
+		 * and the latter for the would-be call inside the
+		 * loop.
+		 */
+		(void)fprintf(stderr, "DEBUG: running:");
+		/* Should be equivilent to 'cmd' (before strsep, of course). */
+		for (i = 0; av[i] != NULL; i++)
+			(void)fprintf(stderr, " %s", av[i]);
+		(void)fprintf(stderr, "\n");
+	}
+
+	/* Create a pipe if necessary and fork the helper program. */
+	if (ofd != NULL) {
+		if (pipe(&pfd[0]) == -1)
+			err(1, "pipe");
+		*ofd = pfd[0];
+		dup2dn = false;
+	}
+	pid = fork();
+	switch (pid) {
+	case 0:
+		/* XXX can we call err() in here? */
+		if (norun)
+			_exit(0);
+		if (ofd != NULL)
+			if (dup2(pfd[1], STDOUT_FILENO) < 0)
+				err(1, "dup2");
+		if (!loudsubs) {
+			nfd = open(_PATH_DEVNULL, O_RDWR);
+			if (nfd == -1)
+				err(1, "open: %s", _PATH_DEVNULL);
+			if (dup2(nfd, STDIN_FILENO) < 0)
+				err(1, "dup2");
+			if (dup2dn)
+				if (dup2(nfd, STDOUT_FILENO) < 0)
+				   err(1, "dup2");
+			if (dup2(nfd, STDERR_FILENO) < 0)
+				err(1, "dup2");
+		}
+
+		(void)execv(av[0], av);
+		warn("exec: %s", av[0]);
+		_exit(-1);
+	case -1:
+		err(1, "fork");
+	}
+
+	free(cmd);
+	free(av);
+	while (waitpid(pid, &status, 0) != pid)
+		;
+	return (WEXITSTATUS(status));
+}
+
+static void
+usage(void)
+{
+
+	fprintf(stderr,
+"usage: %s [-DLMNSX] [-a maxcontig] [-b block-size] [-c cylinders]\n"
+"\t[-d rotdelay] [-e maxbpg] [-F file] [-f frag-size] [-i bytes]\n"
+"\t[-m percent-free] [-n rotational-positions] [-O optimization]\n"
+"\t[-o mount-options] [-p permissions] [-s size] [-w user:group]\n"
+"\tmd-device mount-point\n", getprogname());
+	exit(1);
+}
diff --git a/sbin/mdmfs/pathnames.h b/sbin/mdmfs/pathnames.h
new file mode 100644
index 0000000..d072cf2
--- /dev/null
+++ b/sbin/mdmfs/pathnames.h
@@ -0,0 +1,10 @@
+/* $FreeBSD$ */
+#ifndef	MDMFS_PATHNAMES_H
+#define	MDMFS_PATHNAMES_H
+
+#define	PATH_MDCONFIG	"/sbin/mdconfig"
+#define	PATH_DISKLABEL	"/sbin/disklabel"
+#define	PATH_NEWFS	"/sbin/newfs"
+#define	PATH_MOUNT	"/sbin/mount"
+
+#endif	/* !MDMFS_PATHNAMES_H */