Add gmountver, disk mount verification GEOM class.

Note that due to e.g. write throttling ('wdrain'), it can stall all the disk
I/O instead of just the device it's configured for.  Using it for removable
media is therefore not a good idea.

Reviewed by:	pjd (earlier version)

5 files changed, 194 insertions, 0 deletions

diff --git a/sbin/geom/class/Makefile b/sbin/geom/class/Makefile
index 7b556a8..591f79f 100644
--- a/sbin/geom/class/Makefile
+++ b/sbin/geom/class/Makefile
@@ -10,6 +10,7 @@ SUBDIR+=eli
 SUBDIR+=journal
 SUBDIR+=label
 SUBDIR+=mirror
+SUBDIR+=mountver
 SUBDIR+=multipath
 SUBDIR+=nop
 SUBDIR+=part
diff --git a/sbin/geom/class/mountver/Makefile b/sbin/geom/class/mountver/Makefile
new file mode 100644
index 0000000..d7105d0
--- /dev/null
+++ b/sbin/geom/class/mountver/Makefile
@@ -0,0 +1,7 @@
+# $FreeBSD$
+
+.PATH: ${.CURDIR}/../../misc
+
+CLASS=	mountver
+
+.include <bsd.lib.mk>
diff --git a/sbin/geom/class/mountver/geom_mountver.c b/sbin/geom/class/mountver/geom_mountver.c
new file mode 100644
index 0000000..fa276ca
--- /dev/null
+++ b/sbin/geom/class/mountver/geom_mountver.c
@@ -0,0 +1,56 @@
+/*-
+ * Copyright (c) 2010 Edward Tomasz Napierala <trasz@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <stdio.h>
+#include <stdint.h>
+#include <libgeom.h>
+#include <geom/mountver/g_mountver.h>
+
+#include "core/geom.h"
+
+
+uint32_t lib_version = G_LIB_VERSION;
+uint32_t version = G_MOUNTVER_VERSION;
+
+struct g_command class_commands[] = {
+	{ "create", G_FLAG_VERBOSE | G_FLAG_LOADKLD, NULL,
+	    {
+		G_OPT_SENTINEL
+	    },
+	    NULL, "[-v] dev ..."
+	},
+	{ "destroy", G_FLAG_VERBOSE, NULL,
+	    {
+		{ 'f', "force", NULL, G_TYPE_BOOL },
+		G_OPT_SENTINEL
+	    },
+	    NULL, "[-fv] prov ..."
+	},
+	G_CMD_SENTINEL
+};
diff --git a/sbin/geom/class/mountver/gmountver.8 b/sbin/geom/class/mountver/gmountver.8
new file mode 100644
index 0000000..ff252b1
--- /dev/null
+++ b/sbin/geom/class/mountver/gmountver.8
@@ -0,0 +1,129 @@
+.\"-
+.\" Copyright (c) 2010 Edward Tomasz Napierala
+.\" 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 THE VOICES IN HIS HEAD 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 January 14, 2010
+.Dt GMOUNTVER 8
+.Os
+.Sh NAME
+.Nm gmountver
+.Nd "control utility for disk mount verification GEOM class"
+.Sh SYNOPSIS
+.Nm
+.Cm create
+.Op Fl v
+.Ar dev ...
+.Nm
+.Cm destroy
+.Op Fl fv
+.Ar prov ...
+.Nm
+.Cm list
+.Nm
+.Cm status
+.Op Fl s Ar name
+.Nm
+.Cm load
+.Op Fl v
+.Nm
+.Cm unload
+.Op Fl v
+.Sh DESCRIPTION
+The
+.Nm
+utility is used to control mount verification GEOM class.
+When configured, it passes all the I/O requests to the underlying provider.
+When the underlying provider disappears - for example because the disk device
+got disconnected - it queues all the I/O requests and waits for the provider
+to reappear.
+When that happens, it attaches to it and sends the queued requests.
+.Pp
+The first argument to
+.Nm
+indicates an action to be performed:
+.Bl -tag -width ".Cm destroy"
+.It Cm create
+Cache the given devices with specified
+.Ar name .
+The kernel module
+.Pa geom_mountver.ko
+will be loaded if it is not loaded already.
+.It Cm destroy
+Destroy
+.Ar name .
+.It Cm list
+See
+.Xr geom 8 .
+.It Cm status
+See
+.Xr geom 8 .
+.It Cm load
+See
+.Xr geom 8 .
+.It Cm unload
+See
+.Xr geom 8 .
+.El
+.Pp
+Additional options:
+.Bl -tag -width indent
+.It Fl f
+Force the removal of the specified mountver device.
+.It Fl v
+Be more verbose.
+.El
+.Sh SYSCTL VARIABLES
+The following
+.Xr sysctl 8
+variables can be used to control the behavior of the
+.Nm MOUNTVER
+GEOM class.
+The default value is shown next to each variable.
+.Bl -tag -width indent
+.It Va kern.geom.mountver.debug : No 0
+Debug level of the
+.Nm MOUNTVER
+GEOM class.
+This can be set to a number between 0 and 3 inclusive.
+If set to 0 minimal debug information is printed, and if set to 3 the
+maximum amount of debug information is printed.
+.It Va kern.geom.mountver.check.check_ident : No 1
+This can be set to 0 or 1.  If set to 0,
+.Nm
+will reattach to the device even if the device reports different disk ID.
+.El
+.Sh EXIT STATUS
+Exit status is 0 on success, and 1 if the command fails.
+.Sh SEE ALSO
+.Xr geom 4 ,
+.Xr geom 8
+.Sh HISTORY
+The
+.Nm
+utility appeared in
+.Fx 9.0 .
+.Sh AUTHORS
+.An Edward Tomasz Napierala Aq trasz@FreeBSD.org
diff --git a/sbin/geom/core/geom.8 b/sbin/geom/core/geom.8
index c80816d1..7950468 100644
--- a/sbin/geom/core/geom.8
+++ b/sbin/geom/core/geom.8
@@ -172,6 +172,7 @@ geom md unload
 .Xr gjournal 8 ,
 .Xr glabel 8 ,
 .Xr gmirror 8 ,
+.Xr gmountver 8 ,
 .Xr gmultipath 8 ,
 .Xr gnop 8 ,
 .Xr gpart 8 ,