Re: enhacement to mdmfs

From: Ruben de Groot (mail25_at_bzerk.org)
Date: 11/30/04

  • Next message: Scott Long: "Re: kernel panic with greater that 8 GB of memory" 
    Date: Tue, 30 Nov 2004 13:08:56 +0100
To: Michal Mertl <mime@traveller.cz>

    On Tue, Nov 30, 2004 at 12:21:35PM +0100, Michal Mertl typed:
    > Hello,
    >
    > I've recently shot my foot with mdmfs. Of course it was a pilot error but
    > the funcioanility I was looking for might be usefull.
    >
    > I want to mount vnode-backed md(4) on boot without formatting it (e.g. for
    > a jail). Is it possible with current boot scripts?
    >
    > I wrote a simple patch to mdmfs so such md disk can be put in /etc/fstab.
    > It adds '-K' option do mdmfs(8) to Keep contents. The line to attach such
    > disk in fstab looks like this:
    >
    > md /jail mfs rw,-K,-F=/var/jailfile 0 0
    >
    > Comments welcome. If people find it usefull I'd like to have it commited. I
    > can fill the PR with enhancement request.

    I filed a PR about this allready in October 2003:

    http://www.freebsd.org/cgi/query-pr.cgi?pr=57641

    Ruben

    > Patch attached.
    >
    > --
    > Michal Mertl
    >
    >
    >

    > Index: mdmfs.8
    > ===================================================================
    > RCS file: /home/fcvs/cvs/src/sbin/mdmfs/mdmfs.8,v
    > retrieving revision 1.20
    > diff -u -3 -r1.20 mdmfs.8
    > --- mdmfs.8 17 May 2004 08:35:41 -0000 1.20
    > +++ mdmfs.8 30 Nov 2004 10:56:22 -0000
    > @@ -36,7 +36,7 @@
    > driver
    > .Sh SYNOPSIS
    > .Nm
    > -.Op Fl DLlMNSUX
    > +.Op Fl DKLlMNSUX
    > .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 lNU
    > +.Op Fl KlNU
    > .Op Fl a Ar maxcontig
    > .Op Fl b Ar block-size
    > .Op Fl c Ar cylinders
    > @@ -162,6 +162,12 @@
    > The fragment size of the file system in bytes.
    > .It Fl i Ar bytes
    > Number of bytes per inode.
    > +.It Fl K
    > +Preserve contents of vnode-backed
    > +.Pq Dv MD_VNODE
    > +memory disk.
    > +Must be used in conjunction with
    > +.Fl F .
    > .It Fl l
    > Enable multilabel MAC on the new file system.
    > .It Fl L
    > Index: mdmfs.c
    > ===================================================================
    > RCS file: /home/fcvs/cvs/src/sbin/mdmfs/mdmfs.c,v
    > retrieving revision 1.20
    > diff -u -3 -r1.20 mdmfs.c
    > --- mdmfs.c 17 May 2004 07:07:20 -0000 1.20
    > +++ mdmfs.c 30 Nov 2004 10:51:56 -0000
    > @@ -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, keepdata;
    > char *mtpoint, *unitstr;
    > char *p;
    > int ch;
    > @@ -119,7 +119,7 @@
    > compat = true;
    >
    > while ((ch = getopt(argc, argv,
    > - "a:b:Cc:Dd:e:F:f:hi:LlMm:Nn:O:o:p:Ss:t:Uv:w:X")) != -1)
    > + "a:b:Cc:Dd:e:F:f:hi:KLlMm:Nn:O:o:p:Ss:t:Uv:w:X")) != -1)
    > switch (ch) {
    > case 'a':
    > argappend(&newfs_arg, "-a %s", optarg);
    > @@ -167,6 +167,8 @@
    > usage();
    > loudsubs = true;
    > break;
    > + case 'K':
    > + keepdata = true;
    > case 'l':
    > argappend(&newfs_arg, "-l");
    > break;
    > @@ -233,7 +235,6 @@
    > argv += optind;
    > if (argc < 2)
    > usage();
    > -
    > /* Make compatibility assumptions. */
    > if (compat) {
    > mi.mi_mode = 01777;
    > @@ -258,6 +259,11 @@
    > mtpoint = argv[1];
    > if (!have_mdtype)
    > mdtype = MD_SWAP;
    > +
    > + /* If we want to use vnode backed file and don't newfs it */
    > + if (keepdata && mdtype != MD_VNODE)
    > + err(1, "Must specify -F with -K");
    > +
    > if (softdep)
    > argappend(&newfs_arg, "-U");
    >
    > @@ -268,7 +274,8 @@
    > do_mdconfig_attach_au(mdconfig_arg, mdtype);
    > else
    > do_mdconfig_attach(mdconfig_arg, mdtype);
    > - do_newfs(newfs_arg);
    > + if (!keepdata)
    > + do_newfs(newfs_arg);
    > do_mount(mount_arg, mtpoint);
    > do_mtptsetup(mtpoint, &mi);
    >
    > @@ -665,13 +672,13 @@
    > name = "mdmfs";
    > if (!compat)
    > fprintf(stderr,
    > -"usage: %s [-DLlMNSUX] [-a maxcontig [-b block-size] [-c cylinders]\n"
    > +"usage: %s [-DKLlMNSUX] [-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 [-lNU] [-a maxcontig] [-b block-size] [-c cylinders]\n"
    > +"usage: %s -C [-lKNU] [-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);

    > _______________________________________________
    > freebsd-current@freebsd.org mailing list
    > http://lists.freebsd.org/mailman/listinfo/freebsd-current
    > To unsubscribe, send any mail to "freebsd-current-unsubscribe@freebsd.org"

    _______________________________________________
    freebsd-current@freebsd.org mailing list
    http://lists.freebsd.org/mailman/listinfo/freebsd-current
    To unsubscribe, send any mail to "freebsd-current-unsubscribe@freebsd.org"

  • Next message: Scott Long: "Re: kernel panic with greater that 8 GB of memory"