bin/57641: [patch] missing option in mdmfs (mount_mfs)

[Ruben de Groot]

>Number:         57641
>Category:       bin
>Synopsis:       [patch] missing option in mdmfs (mount_mfs)
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          change-request
>Submitter-Id:   current-users
>Arrival-Date:   Mon Oct 06 01:50:22 PDT 2003
>Closed-Date:
>Last-Modified:
>Originator:     Ruben de Groot
>Release:        FreeBSD 5.1-CURRENT i386
>Organization:
>Environment:
System: FreeBSD ei.bzerk.org 5.1-CURRENT FreeBSD 5.1-CURRENT #1: Thu Oct 2 09:35:43 CEST 2003 root at ei.bzerk.org:/usr/build/usr/obj/usr/build/current/usr/src/sys/SMP-EI i386


>Description:
	
	Currently, mdmfs will allways do a newfs before mounting a mfs.
	When using filesystem image files (MD_VNODE), an option to skip
	the newfs part, preserving the existing filesystem would be
	desirable.

>How-To-Repeat:

root at caliban:/root> tail -1 /etc/fstab
/dev/md1 /jails/jail1 mfs rw,-F/jails/vnodes/jail1fs,async 0 0
root at caliban:/root> mount /jails/jail1
root at caliban:/root> touch /jails/jail1/IMPORTANT_DATA
root at caliban:/root> umount /jails/jail1
root at caliban:/root> mount /jails/jail1
root at caliban:/root> ls /jails/jail1
root at caliban:/root>

>Fix:

	Add a -P option to mdmfs (and mount_mfs) that will skip the
	do_newfs() part. Adding P to the fstab line above like this:

/dev/md1 /jails/jail1 mfs rw,-PF/jails/vnodes/jail1fs,async 0 0

	will preserve data between mounts. The following patch adds the
	-P option (patch for HEAD) :


diff -u sbin/mdmfs.orig/mdmfs.8 sbin/mdmfs/mdmfs.8
--- sbin/mdmfs.orig/mdmfs.8	Wed Aug  6 04:41:52 2003
+++ sbin/mdmfs/mdmfs.8	Mon Oct  6 08:48:27 2003
@@ -36,7 +36,7 @@
 driver
 .Sh SYNOPSIS
 .Nm
-.Op Fl DLMNSUX
+.Op Fl DLMNPSUX
 .Op Fl a Ar maxcontig
 .Op Fl b Ar block-size
 .Op Fl c Ar cylinders
@@ -57,7 +57,7 @@
 .Ar mount-point
 .Nm
 .Fl C
-.Op Fl NU
+.Op Fl NPU
 .Op Fl a Ar maxcontig
 .Op Fl b Ar block-size
 .Op Fl c Ar cylinders
@@ -195,6 +195,11 @@
 See
 .Xr mount 8
 for more information.
+.It Fl P
+Preserve existing filesystem. Do not run newfs. This only makes sense if
+.Fl F
+is specified
+.Pq Dv MD_VNODE .
 .It Fl p Ar permissions
 Set the file (directory) permissions of the mount point
 .Ar mount-point
diff -u sbin/mdmfs.orig/mdmfs.c sbin/mdmfs/mdmfs.c
--- sbin/mdmfs.orig/mdmfs.c	Fri Oct  3 13:50:18 2003
+++ sbin/mdmfs/mdmfs.c	Sat Oct  4 13:41:14 2003
@@ -89,7 +89,7 @@
 	    *mount_arg;
 	enum md_types mdtype;		/* The type of our memory disk. */
 	bool have_mdtype;
-	bool detach, softdep, autounit;
+	bool detach, softdep, autounit, no_newfs;
 	char *mtpoint, *unitstr;
 	char ch, *p;
 	void *set;
@@ -99,6 +99,7 @@
 	detach = true;
 	softdep = true;
 	autounit = false;
+	no_newfs = false;
 	have_mdtype = false;
 	mdname = MD_NAME;
 	mdnamelen = strlen(mdname);
@@ -118,7 +119,7 @@
 		compat = true;
 
 	while ((ch = getopt(argc, argv,
-	    "a:b:Cc:Dd:e:F:f:hi:LMm:Nn:O:o:p:Ss:t:Uv:w:X")) != -1)
+	    "a:b:Cc:Dd:e:F:f:hi:LMm:Nn:O:o:Pp:Ss:t:Uv:w:X")) != -1)
 		switch (ch) {
 		case 'a':
 			argappend(&newfs_arg, "-a %s", optarg);
@@ -189,6 +190,9 @@
 		case 'o':
 			argappend(&mount_arg, "-o %s", optarg);
 			break;
+		case 'P':
+			no_newfs = true;
+			break;
 		case 'p':
 			if (compat)
 				usage();
@@ -264,7 +268,8 @@
 		do_mdconfig_attach_au(mdconfig_arg, mdtype);
 	else
 		do_mdconfig_attach(mdconfig_arg, mdtype);
-	do_newfs(newfs_arg);
+	if (!no_newfs || (mdtype != MD_VNODE))
+		do_newfs(newfs_arg);
 	do_mount(mount_arg, mtpoint);
 	do_mtptsetup(mtpoint, &mi);
 
@@ -661,13 +666,13 @@
 		name = "mdmfs";
 	if (!compat)
 		fprintf(stderr,
-"usage: %s [-DLMNSUX] [-a maxcontig [-b block-size] [-c cylinders]\n"
+"usage: %s [-DLMNPSUX] [-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", name);
 	fprintf(stderr,
-"usage: %s -C [-NU] [-a maxcontig] [-b block-size] [-c cylinders]\n"
+"usage: %s -C [-NPU] [-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);


>Release-Note:
>Audit-Trail:
>Unformatted: