#!/bin/sh

# run lvm scan if udev has settled

extraargs="$*"
type getarg > /dev/null 2>&1 || . /lib/dracut-lib.sh

VGS=$(getargs rd.lvm.vg -d rd_LVM_VG=)
LVS=$(getargs rd.lvm.lv -d rd_LVM_LV=)
SNAPSHOT=$(getargs rd.lvm.snapshot -d rd_LVM_SNAPSHOT=)
SNAPSIZE=$(getargs rd.lvm.snapsize -d rd_LVM_SNAPSIZE=)

# shellcheck disable=SC2174
[ -d /etc/lvm ] || mkdir -m 0755 -p /etc/lvm
# build a list of devices to scan
lvmdevs=$(
    for f in /tmp/.lvm_scan-*; do
        [ -e "$f" ] || continue
        printf '%s' "${f##/tmp/.lvm_scan-} "
    done
)

if [ ! -e /etc/lvm/lvm.conf ]; then
    {
        echo 'devices {'
        printf '    filter = [ '
        for dev in $lvmdevs; do
            printf '"a|^/dev/%s$|", ' "$dev"
        done
        echo '"r/.*/" ]'
        echo '}'

        # establish LVM locking
        if [ -n "$SNAPSHOT" ]; then
            echo 'global {'
            echo '    locking_type = 1'
            echo '    use_lvmetad = 0'
            echo '}'
        else
            echo 'global {'
            echo '    locking_type = 4'
            echo '    use_lvmetad = 0'
            echo '}'
        fi
    } > /etc/lvm/lvm.conf
    lvmwritten=1
fi

check_lvm_ver() {
    maj=$1
    min=$2
    ver=$3
    # --poll is supported since 2.2.57
    [ "$4" -lt "$maj" ] && return 1
    [ "$4" -gt "$maj" ] && return 0
    [ "$5" -lt "$min" ] && return 1
    [ "$5" -gt "$min" ] && return 0
    [ "$6" -ge "$ver" ] && return 0
    return 1
}

# hopefully this output format will never change, e.g.:
#   LVM version:     2.02.53(1) (2009-09-25)
OLDIFS=$IFS
IFS=.
# shellcheck disable=SC2046
set -- $(lvm version 2> /dev/null)
IFS=$OLDIFS
maj=${1##*:}
min=$2
sub=${3%% *}
sub=${sub%%\(*}

lvm_ignorelockingfailure="--ignorelockingfailure"
lvm_quirk_args="--ignorelockingfailure --ignoremonitoring"

check_lvm_ver 2 2 57 "$maj" "$min" "$sub" \
    && lvm_quirk_args="$lvm_quirk_args --poll n"

if check_lvm_ver 2 2 65 "$maj" "$min" "$sub"; then
    lvm_quirk_args=" --sysinit $extraargs"
fi

if check_lvm_ver 2 2 221 "$maj" "$min" "$sub"; then
    lvm_quirk_args=" $extraargs"
    unset lvm_ignorelockingfailure
fi

unset extraargs

export LVM_SUPPRESS_LOCKING_FAILURE_MESSAGES=1

if [ -n "$SNAPSHOT" ]; then
    # HACK - this should probably be done elsewhere or turned into a function
    # Enable read-write LVM locking
    sed -i -e 's/\(^[[:space:]]*\)locking_type[[:space:]]*=[[:space:]]*[[:digit:]]/\1locking_type =  1/' /etc/lvm/lvm.conf

    # Expected SNAPSHOT format "<orig lv name>:<snap lv name>"
    ORIG_LV=${SNAPSHOT%%:*}
    SNAP_LV=${SNAPSHOT##*:}

    info "Removing existing LVM snapshot $SNAP_LV"
    lvm lvremove --force "$SNAP_LV" 2>&1 | vinfo

    # Determine snapshot size
    if [ -z "$SNAPSIZE" ]; then
        SNAPSIZE=$(lvm lvs --noheadings --units m --options lv_size "$ORIG_LV")
        info "No LVM snapshot size provided, using size of $ORIG_LV ($SNAPSIZE)"
    fi

    info "Creating LVM snapshot $SNAP_LV ($SNAPSIZE)"
    lvm lvcreate -s -n "$SNAP_LV" -L "$SNAPSIZE" "$ORIG_LV" 2>&1 | vinfo
fi

if [ -n "$LVS" ]; then
    info "Scanning devices $lvmdevs for LVM logical volumes $LVS"
    lvm lvscan $lvm_ignorelockingfailure 2>&1 | vinfo
    for LV in $LVS; do
        # shellcheck disable=SC2086
        lvm lvchange --yes -K -ay $lvm_quirk_args "$LV" 2>&1 | vinfo
    done
fi

if [ -z "$LVS" ] || [ -n "$VGS" ]; then
    info "Scanning devices $lvmdevs for LVM volume groups $VGS"
    lvm vgscan $lvm_ignorelockingfailure 2>&1 | vinfo
    # shellcheck disable=SC2086
    lvm vgchange -ay $lvm_quirk_args $VGS 2>&1 | vinfo
fi

if [ "$lvmwritten" ]; then
    rm -f -- /etc/lvm/lvm.conf
fi
unset lvmwritten

udevadm settle

need_shutdown