#!/bin/bash
#
# Forcefully unmount ~/.enc and run any hooks
#
# Copyright (C) 2013 Mike Gerwitz
#
#  This program 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.
#
#  This program 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/>.
#
# This script mercilessly unmounts ~/.enc by killing any processes that are
# using files within it, running hooks both before and after. The preunmount
# hook has the chance to abort or delay the operation (delay by re-invoking
# this script).
#
# Run this as root to be certain that unmount will succeed.
##

encpath="$HOME/.enc"
avail="$encpath/.available"
preunmount="$encpath/.preunmount"
postunmount="$encpath/.postunmount"

# if not mounted, then abort
[ -e "$avail" ] || exit

# execute pre-mount script to allow system-specific preparation
[ -x "$preunmount" ] && {
  "$preunmount" || {
    err=$?
    echo "fatal: $preunmount failed!" >&2
    exit $err
  }
}

# kill anything using this process, attempting to do so gracefully first by
# giving them some time to handle SIGTERM, after which we force any
# remaining processes to terminate
s=5
fuser -Mm "$encpath" -k -TERM \
  && echo "Waiting $s seconds for above processes to terminate (SIGTERM)..." \
  && sleep "$s" \
  && echo "Terminating any remaining processes (SIGKILL)..." \
  && fuser -Mm "$encpath" -k -KILL

# now that no processes are using the directory, unmount
fusermount -u "$encpath" \
  && {
    [ ! -x "$postunmount" ] || "$postunmount" || {
      err=$?
      echo "warning: unmounted, but $postunmount failed!"
      exit $err
    }
  } \
  || {
    err=$?
    echo "fatal: umount failed!"
    exit $?
  }

echo "$encpath unmounted."