kexec-tools/kdump_initscripts/init

#!/bin/sh
#
# Licensed under the GPLv2
#
# Copyright 2008, Red Hat, Inc.
# Jeremy Katz <katzj@redhat.com>

emergency_shell()
{
    exec >/dev/console 2>&1 </dev/console
    echo ; echo
    echo $@
    source_all emergency
    echo
    if getarg rdshell || getarg rdbreak; then
        echo "Dropping to debug shell."
        echo
        sh -i
    else
        echo "Boot has failed, sleeping forever."
        while :; do sleep 365d;done
    fi
}

export PATH=/sbin:/bin:/usr/sbin:/usr/bin
export TERM=linux
NEWROOT="/sysroot"

trap "emergency_shell Signal caught!" 0

. /lib/dracut-lib.sh

mknod /dev/null c 1 3

# mount some important things
mount -t proc /proc /proc >/dev/null 2>&1
mount -t sysfs /sys /sys >/dev/null 2>&1

if [ ! -c /dev/ptmx ]; then
    # try to mount devtmpfs
    if ! mount -t devtmpfs -omode=0755 udev /dev >/dev/null 2>&1; then
        # if it failed fall back to normal tmpfs
	mount -t tmpfs -omode=0755 udev /dev >/dev/null 2>&1 
	# Make some basic devices first, let udev handle the rest
	mknod /dev/null c 1 3
	mknod /dev/ptmx c 5 2
	mknod /dev/console c 5 1
	mknod /dev/kmsg c 1 11
    fi
fi

if getarg rdinitdebug; then
    set -x
fi

mkdir /dev/shm
mkdir /dev/pts
mount -t devpts -o gid=5,mode=620 /dev/pts /dev/pts >/dev/null 2>&1

UDEVVERSION=$(udevadm --version)

source_conf /etc/conf.d

# run scriptlets to parse the command line
getarg 'rdbreak=cmdline' && emergency_shell "Break before cmdline"
source_all cmdline

[ -z "$root" ] && die "No or empty root= argument"
[ -z "$rootok" ] && die "Don't know how to handle 'root=$root'"

# Network root scripts may need updated root= options,
# so deposit them where they can see them (udev purges the env)
{
    echo "root='$root'"
    echo "rflags='$rflags'"
    echo "fstype='$fstype'"
    echo "netroot='$netroot'"
    echo "NEWROOT='$NEWROOT'"
} > /tmp/root.info

# pre-udev scripts run before udev starts, and are run only once.
getarg 'rdbreak=pre-udev' && emergency_shell "Break before pre-udev"
source_all pre-udev

# start up udev and trigger cold plugs
udevd --daemon

UDEV_LOG_PRIO_ARG=--log-priority
UDEV_QUEUE_EMPTY="udevadm settle --timeout=0"

if [ $UDEVVERSION -lt 140 ]; then
   UDEV_LOG_PRIO_ARG=--log_priority
   UDEV_QUEUE_EMPTY="udevadm settle --timeout=1"
fi

getarg rdudevinfo && udevadm control $UDEV_LOG_PRIO_ARG=info
getarg rdudevdebug && udevadm control $UDEV_LOG_PRIO_ARG=debug

getarg 'rdbreak=pre-trigger' && emergency_shell "Break before pre-trigger"
source_all pre-trigger

# then the rest
udevadm trigger $udevtriggeropts  >/dev/null 2>&1

getarg 'rdbreak=initqueue' && emergency_shell "Break before initqueue"

i=0
while :; do
    # bail out, if we have mounted the root filesystem
    [ -d "$NEWROOT/proc" ] && break;

    # check if root can be mounted
    [ -e /dev/root ] && break;

    if [ $UDEVVERSION -ge 143 ]; then
        udevadm settle --exit-if-exists=/initqueue/work --exit-if-exists=/dev/root 
    else
        udevadm settle --timeout=30
    fi

    # bail out, if we have mounted the root filesystem
    [ -d "$NEWROOT/proc" ] && break;
    # check if root can be mounted
    [ -e /dev/root ] && break;
 
    unset queuetriggered
    if [ -f /initqueue/work ]; then
        rm /initqueue/work
	queuetriggered="1"
    fi
    	
    for job in /initqueue/*.sh; do
	[ -e "$job" ] || break
        job=$job . $job

        # bail out, if we have mounted the root filesystem
        [ -d "$NEWROOT/proc" ] && break;
        # check if root can be mounted
        [ -e /dev/root ] && break;
    done

    [ -n "$queuetriggered" ] && continue

    if $UDEV_QUEUE_EMPTY >/dev/null 2>&1; then
        # no more udev jobs
        sleep 0.5
        i=$(($i+1))
        [ $i -gt 20 ] \
            && { flock -s 9 ; emergency_shell "No root device found"; } 9>/.console_lock
    fi
done
unset job
unset queuetriggered

# pre-mount happens before we try to mount the root filesystem,
# and happens once.
getarg 'rdbreak=pre-mount' && emergency_shell "Break pre-mount"
source_all pre-mount


getarg 'rdbreak=mount' && emergency_shell "Break mount"
# mount scripts actually try to mount the root filesystem, and may
# be sourced any number of times. As soon as one suceeds, no more are sourced.
i=0
while :; do
    [ -d "$NEWROOT/proc" ] && break;
    for f in /mount/*.sh; do
       [ -f "$f" ] && . "$f"
       [ -d "$NEWROOT/proc" ] && break;
    done

    i=$(($i+1))
    [ $i -gt 20 ] \
        && { flock -s 9 ; emergency_shell "Can't mount root filesystem"; } 9>/.console_lock
done

# We have the root file system mounted under $NEWROOT, so copy 
# the vmcore there and call it a day
#
DATEDIR=`date +%d.%m.%y-%T`
mkdir -p $NEWROOT/var/crash/$DATEDIR
cp /proc/vmcore /var/crash/$DATEDIR/vmcore

# Once the copy is done, just reboot the system
reboot -f