source: trunk/debathena/config/reactivate/debian/16killprocs-no-really @ 25589

#!/bin/sh
#
# A slightly faster way of ending processes in a chroot.
# Copyright (c) 2012 Massachusetts Institute of Technology
#
# This is a derivative work of, and licensed under the same terms as,
# 15killprocs from the schroot (1.4.17-1) package, whose license
# information appears below:
#
# Copyright © 2007       Kees Cook <kees@outflux.net>
# Copyright © 2007-2009  Roger Leigh <rleigh@debian.org>
#
# schroot is free software: you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# schroot 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.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see
# <http://www.gnu.org/licenses/>.
#
#####################################################################

set -e

. "$SETUP_DATA_DIR/common-data"
. "$SETUP_DATA_DIR/common-functions"

if [ -f "$CHROOT_SCRIPT_CONFIG" ]; then
    . "$CHROOT_SCRIPT_CONFIG"
elif [ "$STATUS" = "ok" ]; then
    fatal "script-config file '$CHROOT_SCRIPT_CONFIG' does not exist"
fi

# Wrapper around kill command. Turns errors into
# warnings when running in verbose mode, otherwise
# it ignores them.
# args: parameters for kill
kill_proc()
{
    if ! kill "$@" 2>/dev/null; then
        info "kill $@ failed: process already terminated?"
    fi
}

# Kill all processes that were run from within the chroot environment
# $1: mount base location
do_kill_all()
{
    if [ -z "$1" ]; then
        fatal "No path for finding stray processes: not reaping processes in chroot"
    fi

    info "Killing processes run inside $1"
    # Don't use a pipe into a read loop, just use a normal for loop
    pids=
    for pid in $(ls /proc | egrep '^[[:digit:]]+$'); do
        # Check if process root are the same device/inode as chroot
        # root (for efficiency)
        if [ /proc/"$pid"/root -ef "$1" ]; then
            # Check if process and chroot root are the same (may be
            # different even if device/inode match).
            root=$(readlink /proc/"$pid"/root || true)
            if [ "$root" = "$1" ]; then
                exe=$(readlink /proc/"$pid"/exe || true)
                info "Killing left-over pid $pid (${exe##$1})"
                info "  Sending SIGTERM to pid $pid"

                kill_proc -TERM "$pid"
                # Save the pid
                pids="$pids $pid"
            fi
        fi
    done
    # Wait one second, as most things will respond to TERM gracefully
    sleep 1
    for pid in $pids; do
        count=0
        max=5
        while [ -d /proc/"$pid" ]; do
            count=$(( $count + 1 ))
            info "  Waiting for pid $pid to shut down... ($count/$max)"
            sleep 1
            # Wait for $max seconds for process to die before -9'ing it
            if [ "$count" -eq "$max" ]; then
                info "  Sending SIGKILL to pid $pid"
                kill_proc -KILL "$pid"
                sleep 1
                break
            fi
        done
    done
}

if [ $STAGE = "setup-recover" ] || [ $STAGE = "setup-stop" ]; then
    do_kill_all "$CHROOT_MOUNT_LOCATION"
fi