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

# pre pivot scripts are sourced just before we switch over to the new root.
getarg 'rdbreak=pre-pivot' && emergency_shell "Break pre-pivot"
source_all pre-pivot

# by the time we get here, the root filesystem should be mounted.
# Try to find init.
for i in "$(getarg init=)" /sbin/init /etc/init /init /bin/sh; do
    [ -f "$NEWROOT$i" -a -x "$NEWROOT$i" ] && { INIT="$i"; break; }
done
[ "$INIT" ] || {
    echo "Cannot find init!"
    echo "Please check to make sure you passed a valid root filesystem!"
    emergency_shell
}

getarg rdbreak && emergency_shell "Break before switch_root"

HARD=""
while pidof udevd >/dev/null 2>&1; do 
    for pid in $(pidof udevd); do
	kill $HARD $pid >/dev/null 2>&1
    done
    HARD="-9"
done

# Clean up the environment
for i in $(export -p); do
    i=${i#declare -x}
    i=${i#export}
    i=${i%%=*}
    [ "$i" = "root" -o "$i" = "PATH" -o "$i" = "HOME" -o "$i" = "TERM" ] || unset $i
done

initargs=""
initrdargs="$initrdargs console BOOT_IMAGE rdbreak rdinitdebug rdudevinfo rdudevdebug rdnetdebug rdcopystate rdshell"

for x in "$@"; do
    for s in $initrdargs; do       
	[ "${x%%=*}" = $s ] && continue 2
    done
    initargs="$initargs $x"
done

# Copy state
mkdir /dev/.initramfs/
if getarg rdcopystate; then
    cp /tmp/* /dev/.initramfs/ >/dev/null 2>&1
else
    cp /tmp/net.* /dev/.initramfs/ >/dev/null 2>&1
fi

exec switch_root "$NEWROOT" "$INIT" $initargs || {
    # davej doesn't like initrd bugs
    echo "Something went very badly wrong in the initrd.  Please "
    echo "file a bug against mkinitrd."
    emergency_shell
}