kexec-tools/mkdumprd

#!/bin/bash --norc
# New mkdumprd
#
# Copyright 2011 Red Hat, Inc.
#
# Written by Cong Wang <amwang@redhat.com>
#

[[ $dracutbasedir ]] || dracutbasedir=/usr/lib/dracut
. $dracutbasedir/dracut-functions.sh
. /lib/kdump/kdump-lib.sh
export IN_KDUMP=1

conf_file="/etc/kdump.conf"
SSH_KEY_LOCATION="/root/.ssh/kdump_id_rsa"
SAVE_PATH=$(get_save_path)
OVERRIDE_RESETTABLE=0

extra_modules=""
dracut_args="--quiet --hostonly --hostonly-cmdline --hostonly-i18n --hostonly-mode strict -o \"plymouth dash resume ifcfg earlykdump\""

is_wdt_addition_needed() {
	local active

	is_wdt_mod_omitted
	[[ $? -eq 0 ]] && return 1
	[[ -d /sys/class/watchdog/ ]] || return 1
	for dir in /sys/class/watchdog/*; do
		[[ -f "$dir/state" ]] || continue
		active=$(< "$dir/state")
		[[ "$active" =  "active" ]] && return 0
	done
	return 1
}

add_dracut_arg() {
    dracut_args="$dracut_args $@"
}

add_dracut_module() {
    add_dracut_arg "--add" "\"$1\""
}

add_dracut_mount() {
    add_dracut_arg "--mount" "\"$1\""
}

add_dracut_sshkey() {
    add_dracut_arg "--sshkey" "\"$1\""
}

# caller should ensure $1 is valid and mounted in 1st kernel
to_mount() {
    local _dev=$1 _source _target _fstype _options _mntopts _pdev

    _source=$(findmnt -k -f -n -r -o SOURCE $_dev)
    _target=$(get_mntpoint_from_target $_dev)
    # mount under /sysroot if dump to root disk or mount under
    #/kdumproot/$_target in other cases in 2nd kernel. systemd
    #will be in charge to umount it.

    if [ "$_target" = "/" ];then
        _target="/sysroot"
    else
        _target="/kdumproot/$_target"
    fi

    _fstype=$(findmnt -k -f -n -r -o FSTYPE $_dev)
    [[ -e /etc/fstab ]] && _options=$(findmnt --fstab -f -n -r -o OPTIONS $_dev)
    if [ -z "$_options" ]; then
        _options=$(findmnt -k -f -n -r -o OPTIONS $_dev)
        if [[ $_fstype == "nfs"* ]]; then
            _options=$(echo $_options | sed 's/,addr=[^,]*//')
            _options=$(echo $_options | sed 's/,proto=[^,]*//')
            _options=$(echo $_options | sed 's/,clientaddr=[^,]*//')
        fi
    fi
    # mount fs target as rw in 2nd kernel
    _options=$(echo $_options | sed 's/\(^\|,\)ro\($\|,\)/\1rw\2/g')
    # with 'noauto' in fstab nfs and non-root disk mount will fail in 2nd
    # kernel, filter it out here.
    _options=$(echo $_options | sed 's/\(^\|,\)noauto\($\|,\)/\1/g')
    # drop nofail or nobootwait
    _options=$(echo $_options | sed 's/\(^\|,\)nofail\($\|,\)/\1/g')
    _options=$(echo $_options | sed 's/\(^\|,\)nobootwait\($\|,\)/\1/g')
    # use both nofail and x-systemd.before to ensure systemd will try best to
    # mount it before kdump starts, this is an attempt to improve robustness
    _options="$_options,nofail,x-systemd.before=initrd-fs.target"

    _mntopts="$_target $_fstype $_options"
    #for non-nfs _dev converting to use udev persistent name
    if [ -b "$_source" ]; then
        _pdev="$(get_persistent_dev $_source)"
        if [ -z "$_pdev" ]; then
            return 1
        fi

    else
        _pdev=$_dev
    fi

    echo "$_pdev $_mntopts"
}

is_readonly_mount() {
    local _mnt
    _mnt=$(findmnt -k -f -n -r -o OPTIONS $1)

    #fs/proc_namespace.c: show_mountinfo():
    #seq_puts(m, mnt->mnt_flags & MNT_READONLY ? " ro" : " rw");
    [[ "$_mnt" =~ ^ro ]]
}

#Function: get_ssh_size
#$1=dump target
#called from while loop and shouldn't read from stdin, so we're using "ssh -n"
get_ssh_size() {
    local _opt _out _size
    _opt="-i $SSH_KEY_LOCATION -o BatchMode=yes -o StrictHostKeyChecking=yes"
    _out=$(ssh -q -n $_opt $1 "df -P $SAVE_PATH")
    [ $? -ne 0 ] && {
        perror_exit "checking remote ssh server available size failed."
    }

    #ssh output removed the line break, so print field NF-2
    _size=$(echo -n $_out| awk '{avail=NF-2; print $avail}')
    echo -n $_size
}

#mkdir if save path does not exist on ssh dump target
#$1=ssh dump target
#caller should ensure write permission on $1:$SAVE_PATH
#called from while loop and shouldn't read from stdin, so we're using "ssh -n"
mkdir_save_path_ssh()
{
    local _opt _dir
    _opt="-i $SSH_KEY_LOCATION -o BatchMode=yes -o StrictHostKeyChecking=yes"
    ssh -qn $_opt $1 mkdir -p $SAVE_PATH 2>&1 > /dev/null
    _ret=$?
    if [ $_ret -ne 0 ]; then
        perror_exit "mkdir failed on $1:$SAVE_PATH"
    fi

    #check whether user has write permission on $1:$SAVE_PATH
    _dir=$(ssh -qn $_opt $1 mktemp -dqp $SAVE_PATH 2>/dev/null)
    _ret=$?
    if [ $_ret -ne 0 ]; then
        perror_exit "Could not create temporary directory on $1:$SAVE_PATH. Make sure user has write permission on destination"
    fi
    ssh -qn $_opt $1 rmdir $_dir

    return 0
}

#Function: get_fs_size
#$1=dump target
get_fs_size() {
    local _mnt=$(get_mntpoint_from_target $1)
    echo -n $(df -P "${_mnt}/$SAVE_PATH"|tail -1|awk '{print $4}')
}

#Function: get_raw_size
#$1=dump target
get_raw_size() {
        echo -n $(fdisk -s "$1")
}

#Function: check_size
#$1: dump type string ('raw', 'fs', 'ssh')
#$2: dump target
check_size() {
    local avail memtotal

    memtotal=$(awk '/MemTotal/{print $2}' /proc/meminfo)
    case "$1" in
        raw)
            avail=$(get_raw_size "$2")
            ;;
        ssh)
            avail=$(get_ssh_size "$2")
            ;;
        fs)
            avail=$(get_fs_size "$2")
            ;;
        *)
            return
    esac

    if [ $? -ne 0 ]; then
            perror_exit "Check dump target size failed"
    fi

    if [ $avail -lt $memtotal ]; then
        echo "Warning: There might not be enough space to save a vmcore."
        echo "         The size of $2 should be greater than $memtotal kilo bytes."
    fi
}

# $1: core_collector config value
verify_core_collector() {
    local _cmd="${1%% *}"
    local _params="${1#* }"

    if [ "$_cmd" != "makedumpfile" ]; then
        if is_raw_dump_target; then
            echo "Warning: specifying a non-makedumpfile core collector, you will have to recover the vmcore manually."
        fi
        return
    fi

    if is_ssh_dump_target || is_raw_dump_target; then
        if ! strstr "$_params" "-F"; then
            perror_exit "The specified dump target needs makedumpfile \"-F\" option."
        fi
        _params="$_params vmcore"
    else
        _params="$_params vmcore dumpfile"
    fi

    if ! $_cmd --check-params $_params; then
        perror_exit "makedumpfile parameter check failed."
    fi
}

add_mount() {
    local _mnt=$(to_mount "$1")

    if [ $? -ne 0 ]; then
        exit 1
    fi

    add_dracut_mount "$_mnt"
}

#handle the case user does not specify the dump target explicitly
handle_default_dump_target()
{
    local _target
    local _mntpoint

    is_user_configured_dump_target && return

    check_save_path_fs $SAVE_PATH

    _save_path=$(get_bind_mount_source $SAVE_PATH)
    _target=$(get_target_from_path $_save_path)
    _mntpoint=$(get_mntpoint_from_target $_target)

    SAVE_PATH=${_save_path##"$_mntpoint"}
    add_mount "$_target"
    check_size fs $_target
}

get_override_resettable()
{
    local override_resettable

    override_resettable=$(grep "^override_resettable" $conf_file)
    if [ -n "$override_resettable" ]; then
        OVERRIDE_RESETTABLE=$(echo $override_resettable | cut -d' '  -f2)
        if [ "$OVERRIDE_RESETTABLE" != "0" ] && [ "$OVERRIDE_RESETTABLE" != "1" ];then
            perror_exit "override_resettable value $OVERRIDE_RESETTABLE is invalid"
        fi
    fi
}


# $1: function name
for_each_block_target()
{
    local dev majmin

    for dev in $(get_kdump_targets); do
        [ -b "$dev" ] || continue
        majmin=$(get_maj_min $dev)
        check_block_and_slaves $1 $majmin && return 1
    done

    return 0
}



#judge if a specific device with $1 is unresettable
#return false if unresettable.
is_unresettable()
{
    local path="/sys/$(udevadm info --query=all --path=/sys/dev/block/$1 | awk '/^P:/ {print $2}' | sed -e 's/\(cciss[0-9]\+\/\).*/\1/g' -e 's/\/block\/.*$//')/resettable"
    local resettable=1

    if [ -f "$path" ]
    then
        resettable="$(cat $path)"
        [ $resettable -eq 0 -a "$OVERRIDE_RESETTABLE" -eq 0 ] && {
            local device=$(udevadm info --query=all --path=/sys/dev/block/$1 | awk -F= '/DEVNAME/{print $2}')
            echo "Error: Can not save vmcore because device $device is unresettable"
            return 0
        }
    fi

    return 1
}

#check if machine is resettable.
#return true if resettable
check_resettable()
{
    local _ret _target

    get_override_resettable

    for_each_block_target is_unresettable
    _ret=$?

    [ $_ret -eq 0 ] && return

    return 1
}

# $1: maj:min
is_crypt()
{
    local majmin=$1 dev line ID_FS_TYPE=""

    line=$(udevadm info --query=property --path=/sys/dev/block/$majmin \
            | grep "^ID_FS_TYPE")
    eval "$line"
    [[ "$ID_FS_TYPE" = "crypto_LUKS" ]] && {
        dev=$(udevadm info --query=all --path=/sys/dev/block/$majmin | awk -F= '/DEVNAME/{print $2}')
        echo "Device $dev is encrypted."
        return 0
    }
    return 1
}

check_crypt()
{
    local _ret _target

    for_each_block_target is_crypt
    _ret=$?

    [ $_ret -eq 0 ] && return

    return 1
}

if ! check_resettable; then
    exit 1
fi

if ! check_crypt; then
    echo "Warning: Encrypted device is in dump path. User will prompted for password during second kernel boot." 
fi

# firstly get right SSH_KEY_LOCATION
keyfile=$(awk '/^sshkey/ {print $2}' $conf_file)
if [ -f "$keyfile" ]; then
    # canonicalize the path
    SSH_KEY_LOCATION=$(/usr/bin/readlink -m $keyfile)
fi

if [ "$(uname -m)" = "s390x" ]; then
    add_dracut_module "znet"
fi

if is_wdt_addition_needed; then
    add_dracut_arg "-a" "watchdog"
fi

while read config_opt config_val;
do
    # remove inline comments after the end of a directive.
    case "$config_opt" in
    extra_modules)
        extra_modules="$extra_modules $config_val"
        ;;
    ext[234]|xfs|btrfs|minix|nfs)
        if ! findmnt $config_val >/dev/null; then
            perror_exit "Dump target $config_val is probably not mounted."
        fi

        # User configured target, use $SAVE_PATH as the dump path within the target
        check_save_path_user_configured "$config_val" "$SAVE_PATH"
        check_size fs "$config_val"
        add_mount "$config_val"
        ;;
    raw)
        # checking raw disk writable
        dd if=$config_val count=1 of=/dev/null > /dev/null 2>&1 || {
            perror_exit "Bad raw disk $config_val"
        }
        _praw=$(persistent_policy="by-id" get_persistent_dev $config_val)
        if [ -z "$_praw" ]; then
            exit 1
        fi
        add_dracut_arg "--device" "$_praw"
        check_size raw $config_val
        ;;
    ssh)
        if strstr "$config_val" "@";
        then
            mkdir_save_path_ssh $config_val
            check_size ssh $config_val
            add_dracut_module "ssh-client"
            add_dracut_sshkey "$SSH_KEY_LOCATION"
        else
            perror_exit "Bad ssh dump target $config_val"
        fi
        ;;
    core_collector)
        verify_core_collector "$config_val"
        ;;
    dracut_args)
        add_dracut_arg $config_val
        ;;
    *)
        ;;
    esac
done <<< "$(read_strip_comments $conf_file)"

handle_default_dump_target

if [ -n "$extra_modules" ]
then
    add_dracut_arg "--add-drivers" "$extra_modules"
fi

if ! is_fadump_capable; then
    # The 2nd rootfs mount stays behind the normal dump target mount,
    # so it doesn't affect the logic of check_dump_fs_modified().
    is_dump_to_rootfs && add_mount "$(to_dev_name $(get_root_fs_device))"

    add_dracut_arg "--no-hostonly-default-device"
fi

echo "$dracut_args $@" | xargs dracut

_rc=$?
sync
exit $_rc