Bugfix: 3744

When a new member is added to a RAID group that holds the root filesystem,
we need to re-install grub so that the new disk will be bootable.  But this
can only be done after the RAID set has completed rebuilding.  Added mechanism
that uses the event notification infrastructure of "mdadm" to trigger
the re-installation of grub after the rebuild completes.

2 files changed, 111 insertions, 0 deletions

diff --git a/debian/vyatta-cfg-system.postinst.in b/debian/vyatta-cfg-system.postinst.in
index 53fa062c..21d7ff32 100644
--- a/debian/vyatta-cfg-system.postinst.in
+++ b/debian/vyatta-cfg-system.postinst.in
@@ -111,6 +111,13 @@ sed -i 's/requisite[ \t][ \t]*pam_securetty.so/required pam_securetty.so/' $root
 
 [ grep "blacklist.*snd-pcsp" >&/dev/null ] || echo "blacklist snd-pcsp" >>/etc/modprobe.d/blacklist
 
+#
+# Ask mdadm to call our own event handling daemon
+#
+if [ -e /etc/default/mdadm ]; then
+    sed -i 's+^DAEMON_OPTIONS=.*$+DAEMON_OPTIONS="--syslog --program /opt/vyatta/sbin/vyatta-raid-event"+' /etc/default/mdadm
+fi
+
 # Local Variables:
 # mode: shell-script
 # sh-indentation: 4
diff --git a/scripts/vyatta-raid-event b/scripts/vyatta-raid-event
new file mode 100644
index 00000000..f279a57d
--- /dev/null
+++ b/scripts/vyatta-raid-event
@@ -0,0 +1,104 @@
+#!/bin/bash
+#
+# **** License ****
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# General Public License for more details.
+#
+# This code was originally developed by Vyatta, Inc.
+# Portions created by Vyatta are Copyright (C) 2006, 2007 Vyatta, Inc.
+# All Rights Reserved.
+#
+# Author: Bob Gilligan <gilligan@vyatta.com>
+# Date: 2008
+# Description: A script to handle events from the Linux Software RAID 
+#              subsystem.
+#
+# **** End License ****
+#
+# This script is called by the "mdadm" daemon running in "monitor" mode
+# whenever an event occurs in in the RAID subsytem.  The script is called
+# with two or three arguments: The first argument is always the name of
+# the event, e.g. "RebuildFinished".  The second argument is the name of
+# the RAID set device that the event pertains to, e.g. "/dev/md0".  The
+# third argument is provided for some events, and gives the name of the
+# RAID set member that the event pertains to, e.g. "/dev/sda2".
+#
+# See the mdadm(8) man page for more details on the events that it provides.
+#
+
+# Script will be called with 2 or 3 arguments, depending on the event
+if [ $# -lt 2 ]; then
+	logger -t "RAID" -p local0.warning "vyatta-raid-event: Error: Not enough args: $*"
+	# We can't do anything if we don't know event and RAID device it
+	# pertains to.
+	exit 1
+fi
+if [ $# -gt 3 ]; then
+	logger -t "RAID" -p local0.warning "vyatta-raid-event: Warning: too many args: $*"
+	# Be Robust: Try to complete task with args we know about
+fi
+
+event=$1
+raid_set=$2
+
+case $event in
+
+    RebuildFinished)
+    logger -t "RAID" -p local0.warning "event ${event} ${raid_set}"
+
+    # We need to update grub at the time that a resync completes
+    # on the root filesystem so that the new member disk will be
+    # bootable.
+    mounted_on=`mount | grep "^${raid_set}" | awk '{ print $3 }'`
+    if [ "$mounted_on" = "/" ]; then
+	raid_set_dev=${raid_set##*/}
+	if [ -e /sys/block/${raid_set_dev}/md/degraded ]; then
+	    degraded=`cat /sys/block/${raid_set_dev}/md/degraded`
+	else
+	    degraded=0
+	fi
+	if [ $degraded -eq 0 ]; then
+            drive=${member_to_add%%[0-9]*}
+            logger -t "RAID" -p local0.warning \
+		"RAID set ${raid_set} holds root filesystem. Updating grub."
+	    touch /tmp/raid-grub-install-log
+            grub-install --no-floppy --recheck --root-directory=/ ${raid_set} \
+		>> /tmp/raid-grub-install-log 2>&1
+	    if [ $? -ne 0 ]; then
+		logger -t "RAID" -p local0.warning \
+		    "grub-installed failed for $raid_set"
+	    fi
+	else
+	    logger -t "RAID" -p local0.warning \
+		"RAID set ${raid_set} is still degraded.  No action taken."
+	fi
+    else
+	logger -t "RAID" -p local0.warning \
+	    "RAID set ${raid_set} does not hold root filesystem.  No action taken"
+    fi
+    ;;
+
+    DeviceDisappeared | RebuildStarted | Rebuild?? | NewArray | \
+	DegradedArray | MoveSpare | SparesMissing | TestMessage)
+    logger -t "RAID" -p local0.warning \
+	"event ${event} ${raid_set}: No action taken"
+    ;;
+
+    Fail | FailSpare | SpareActive)
+    member=$3
+    logger -t "RAID" -p local0.warning \
+	"event ${event} ${raid_set} ${member}: No action taken"
+    ;;
+
+    *)
+    logger -t "RAID" -p local0.warning \
+	"event ${event} unknown. No action taken"
+    ;;
+    
+    esac