Implement a better compatibility mode with mount_mfs. It is the

default if the executable is named (called as) "mount_*", or can be
enabled with the -C option.  This allows users to leave their old
fstab entires unchanged (modulo symlink'ing mdmfs to mount(md|mfs))
and have things behave the way they should (by emulating mount_mfs
silliness), while still allowing mdmfs to be used as a generic
make-an-md-and-mount-it type thing.

Right now, the only effects of this option is to set the mount-point
mode to 01777 as if "-p 1777" was given, and to complain about getting
command-line options that mount_mfs didn't take (e.g., -X, -L, et al).
The latter is mostly to try to catch operator errors.

Also implement -U, which turns on soft-updates.  It's redundant (since
softdep is the default), but implement it anyway for compatibility.

2 files changed, 120 insertions, 6 deletions

diff --git a/sbin/mdmfs/mdmfs.8 b/sbin/mdmfs/mdmfs.8
index 74192f4949db..d7043168570f 100644
--- a/sbin/mdmfs/mdmfs.8
+++ b/sbin/mdmfs/mdmfs.8
@@ -25,7 +25,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd May 26, 2001
+.Dd August 5, 2001
 .Dt MDMFS 8
 .Os
 .Sh NAME
@@ -35,7 +35,7 @@
 driver
 .Sh SYNOPSIS
 .Nm
-.Op Fl DLMNSX
+.Op Fl DLMNSUX
 .Op Fl a Ar maxcontig
 .Op Fl b Ar block-size
 .Op Fl c Ar cylinders
@@ -53,6 +53,24 @@ driver
 .Op Fl w Ar user : Ns Ar group
 .Ar md-device
 .Ar mount-point
+.Nm
+.Fl C
+.Op Fl NU
+.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 s Ar size
+.Ar md-device
+.Ar mount-point
 .Sh DESCRIPTION
 The
 .Nm
@@ -110,6 +128,13 @@ out before forcing a rotational delay
 option).
 .It Fl b Ar block-size
 The block size of the filesystem, in bytes.
+.It Fl C
+Enable full compatibility mode with
+.Xr mount_mfs 8 .
+See the
+.\" XXX link to another section?
+.Em COMPATIBILITY
+section for more information.
 .It Fl c Ar cylinders
 The number of cylinders per cylinder group in the filesystem.
 .It Fl D
@@ -192,6 +217,13 @@ and the optional
 .Xr malloc 9
 backed disks
 .Pq Dv MD_MALLOC .
+.It Fl U
+Enable soft-updates on the filesystem.
+This is the default, even in compatibility mode, and is accepted only
+for compatibility.
+It is only really useful to negate the
+.Fl S
+flag, should such a need occur.
 .It Fl w Ar user : Ns Ar group
 Set the owner and group to
 .Ar user
@@ -257,8 +289,46 @@ do not use soft-updates on it and mount it
 .Cm async :
 .Pp
 .Dl "mdmfs -M -S -o async -s 16m md1 /tmp"
+.Sh COMPATIBILITY
+.Nm ,
+while designed to be fully compatible with
+.Xr mount_mfs 8 ,
+can be useful by itself.
+Since
+.Xr mount_mfs 8
+has some silly defaults, a
+.Dq full compatibility
+mode is provided for the case where bug-to-bug compatibility is desired.
+.Pp
+Full compatibility is enabled with the
+.Fl C
+flag,
+or by starting
+.Nm
+with
+.Li mount_
+at the beginning of its name
+(as returned by
+.Xr getprogname 3 ) .
+In this mode, only the options which would be accepted by
+.Xr mount_mfs 8
+are valid.
+Furthermore, the following behavior, as done by
+.Xr mount_mfs 8 ,
+is duplicated:
+.Bl -bullet -offset indent -compat
+.It
+The file mode of
+.Ar mount-point
+is set to
+.Li 01777
+as if
+.Fl p Ar 1777
+was given on the command line.
+.El
 .Sh SEE ALSO
 .Xr md 4 ,
+.Xr fstab 5 ,
 .Xr disklabel 8 ,
 .Xr mdconfig 8 ,
 .Xr mount 8 ,
diff --git a/sbin/mdmfs/mdmfs.c b/sbin/mdmfs/mdmfs.c
index 02c336a254cc..62a3316bbb0e 100644
--- a/sbin/mdmfs/mdmfs.c
+++ b/sbin/mdmfs/mdmfs.c
@@ -65,6 +65,7 @@ struct mtpt_info {
 	bool		 mi_have_mode;
 };
 
+static	bool compat;		/* Full compatibility with mount_mfs? */
 static	bool debug;		/* Emit debugging information? */
 static	bool loudsubs;		/* Suppress output from helper programs? */
 static	bool norun;		/* Actually run the helper programs? */
@@ -115,8 +116,12 @@ main(int argc, char **argv)
 	newfs_arg = strdup("");
 	mount_arg = strdup("");
 
+	/* If we were started as mount_*, imply -C. */
+	if (strncmp(getprogname(), "mount_", 6) == 0)
+		compat = true;
+
 	while ((ch = getopt(argc, argv,
-	    "a:b:c:Dd:e:F:f:hi:LMm:Nn:O:o:p:Ss:t:w:X")) != -1)
+	    "a:b:Cc:Dd:e:F:f:hi:LMm:Nn:O:o:p:Ss:t:Uw:X")) != -1)
 		switch (ch) {
 		case 'a':
 			argappend(&newfs_arg, "-a %s", optarg);
@@ -124,10 +129,17 @@ main(int argc, char **argv)
 		case 'b':
 			argappend(&newfs_arg, "-b %s", optarg);
 			break;
+		case 'C':
+			if (compat)
+				usage();
+			compat = true;
+			break;
 		case 'c':
 			argappend(&newfs_arg, "-c %s", optarg);
 			break;
 		case 'D':
+			if (compat)
+				usage();
 			detach = false;
 			break;
 		case 'd':
@@ -153,6 +165,8 @@ main(int argc, char **argv)
 			argappend(&newfs_arg, "-i %s", optarg);
 			break;
 		case 'L':
+			if (compat)
+				usage();
 			loudsubs = true;
 			break;
 		case 'M':
@@ -165,6 +179,8 @@ main(int argc, char **argv)
 			argappend(&newfs_arg, "-m %s", optarg);
 			break;
 		case 'N':
+			if (compat)
+				usage();
 			norun = true;
 			break;
 		case 'n':
@@ -177,6 +193,8 @@ main(int argc, char **argv)
 			argappend(&mount_arg, "-o %s", optarg);
 			break;
 		case 'p':
+			if (compat)
+				usage();
 			if (*optarg >= '0' && *optarg <= '7')
 				mi.mi_mode = strtol(optarg, NULL, 8);
 			if ((mi.mi_mode & ~07777) != 0)
@@ -184,15 +202,24 @@ main(int argc, char **argv)
 			mi.mi_have_mode = true;
 			break;
 		case 'S':
+			if (compat)
+				usage();
 			softdep = false;
 			break;
 		case 's':
 			argappend(&mdconfig_arg, "-s %s", optarg);
 			break;
+		case 'U':
+			softdep = true;
+			break;
 		case 'w':
+			if (compat)
+				usage();
 			extract_ugid(optarg, &mi);
 			break;
 		case 'X':
+			if (compat)
+				usage();
 			debug = true;
 			break;
 		default:
@@ -203,6 +230,12 @@ main(int argc, char **argv)
 	if (argc < 2)
 		usage();
 
+	/* Make compatibility assumptions. */
+	if (compat) {
+		mi.mi_mode = 01777;
+		mi.mi_have_mode = true;
+	}
+
 	/* Derive 'unit' (global). */
 	unitstr = argv[0];
 	if (strncmp(unitstr, "/dev/", 5) == 0)
@@ -634,12 +667,23 @@ run(int *ofd, const char *cmdline, ...)
 static void
 usage(void)
 {
+	const char *name;
 
-	fprintf(stderr,
-"usage: %s [-DLMNSX] [-a maxcontig] [-b block-size] [-c cylinders]\n"
+	if (compat)
+		name = getprogname();
+	else
+		name = "mdmfs";
+	if (!compat)
+		fprintf(stderr,
+"Usage: %s [-DLMNSUX] [-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());
+"\tmd-device mount-point\n", name);
+	fprintf(stderr,
+"Usage: %s -C [-NU] [-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] [-s size] md-device mount-point\n", name);
 	exit(1);
 }