# Trying to fix a tgt bug
# tgt can fail when we execute the `reload tgt` and `restart tgt` comands.
# See: https://bugs.launchpad.net/ubuntu/+source/tgt/+bug/1294267
#      "tgt doesn't export some LUNs after a reload operation (SIGHUP)"

author "Rarylson Freitas <rarylson@gmail.com>"

# Sorry. TGT doesn't permit us change the reload behavior
# So, never run a `reload tgt`. It is broken. After all, if you run 
# `reload tgt` and see the syslog, you can find an error message like this:
#     "[...]tgtd: tgtd logger exits abnormally [...]"
# We want to do this reload:
#     /usr/sbin/tgt-admin --update ALL
# See: https://github.com/fujita/tgt/blob/master/scripts/initd.sample

# To provide the `restart` functionality, we'll save the actually opened 
# devices for later processing.
# From upstart cookbook: "[...] if the job contains post-stop, pre-start or 
# post-start stanzas, these will NOT be run for a restart. However, a pre-stop
# stanza will be run."
# See: "http://upstart.ubuntu.com/cookbook/#restart
pre-stop script
    # Update actually opened devices
    mkdir -p /var/spool/tgt/
    tgt-admin --dump | grep -o "\(backing-store\|direct-store\) \(.*\)" | 
        cut -d' ' -f2 > /var/spool/tgt/devices
end script

# If start would fail, we'll add some delay to avoid this
post-start script
    # Sleep until all devices are closed
    _device_opened=1
    _time=10
    while [ "$_time" -gt "0" ]; do
        # Exit when all devices are closed
        if [ `cat /var/spool/tgt/devices | wc -l` -eq "0" ]; then
            _device_opened=0
            break
        fi
        _return=`cat /var/spool/tgt/devices | xargs lsof -V | 
            grep -v "no file use located" | wc -l`
        if [ "$_return" -eq "0" ]; then
            _device_opened=0
            break
        fi
        # Sleep some time if some device still opened
        sleep 0.1
        _time=`expr $_time - 1`
    done
    # Log if there are some device opened
    [ "$_device_opened" -eq "1" ] && logger -t "tgtd" -p "WARN" "some" \
        "backing-store or direct-store may not have corectly added to a LUN"
    # Load config file
    /usr/sbin/tgt-admin -e
end script