source: vendor/current/ctdb/config/nfs-linux-kernel-callout

#!/bin/sh

# Exit on 1st error
set -e

# NFS exports file.  Some code below keeps a cache of output derived
# from exportfs(8).  When this file is updated the cache is invalid
# and needs to be regenerated.
#
# To change the file, edit the default value below.  Do not set
# CTDB_NFS_EXPORTS_FILE - it isn't a configuration variable, just a
# hook for testing.
nfs_exports_file="${CTDB_NFS_EXPORTS_FILE:-/var/lib/nfs/etab}"

# Red Hat
nfs_service="nfs"
nfslock_service="nfslock"
nfs_config="/etc/sysconfig/nfs"

# SUSE
#nfs_service="nfsserver"
#nfslock_service=""
#nfs_config="/etc/sysconfig/nfs"

# Debian
#nfs_service="nfs-kernel-server"
#nfslock_service=""
#nfs_config="/etc/default/nfs-kernel-server"

# Override for unit testing
if [ -z "$PROCFS_PATH" ] ; then
    PROCFS_PATH="/proc"
fi

##################################################

usage ()
{
    _c=$(basename $0)
    cat <<EOF
usage: $_c { shutdown | startup }
       $_c { stop | start } { nfs | nlockmgr }
       $_c { monitor-list-shares | monitor-post }
       $_c { register }
EOF
    exit 1
}


##################################################
# Basic service stop and start

basic_stop ()
{
    case "$1" in
        nfs)
            service "$nfs_service" stop
            if [ -n "$nfslock_service" ] ; then
                service "$nfslock_service" stop
            fi
            ;;
        nfslock)
            if [ -n "$nfslock_service" ] ; then
                service "$nfslock_service" stop
            else
                service "$nfs_service" stop
            fi
            ;;
        *)
            usage
    esac
}

basic_start ()
{
    case "$1" in
        nfs)
            if [ -n "$nfslock_service" ] ; then
                service "$nfslock_service" start
            fi
            service "$nfs_service" start
            ;;
        nfslock)
            if [ -n "$nfslock_service" ] ; then
                service "$nfslock_service" start
            else
                service "$nfs_service" start
            fi
            ;;
        *)
            usage
    esac
}

##################################################
# service "stop" and "start" options for restarting

service_stop ()
{
    case "$1" in
        nfs)
            echo 0 >"${PROCFS_PATH}/fs/nfsd/threads"
            basic_stop "nfs" >/dev/null 2>&1 || true
            pkill -9 nfsd
            ;;
        nlockmgr)
            basic_stop "nfslock" >/dev/null 2>&1 || true
            ;;
        *)
            usage
    esac
}

service_start ()
{
    case "$1" in
        nfs)
            basic_start "nfs"
            ;;
        nlockmgr)
            basic_start "nfslock"
            ;;
        *)
            usage
    esac
}

##################################################
# service init startup and final shutdown

nfs_shutdown ()
{
    basic_stop "nfs"
}

nfs_startup ()
{
    basic_stop "nfs" || true
    basic_start "nfs"
    _f="${PROCFS_PATH}/sys/net/ipv4/tcp_tw_recycle"
    if [ "$_f" ] ; then
        echo 1 >"$_f"
    fi
}

##################################################
# monitor-post support

nfs_check_thread_count ()
{
    # Load NFS configuration to get desired number of threads.
    if [ -r "$nfs_config" ] ; then
        . "$nfs_config"
    fi

    # If $RPCNFSDCOUNT/$USE_KERNEL_NFSD_NUMBER isn't set then we could
    # guess the default from the initscript.  However, let's just
    # assume that those using the default don't care about the number
    # of threads and that they have switched on this feature in error.
    _configured_threads="${RPCNFSDCOUNT:-${USE_KERNEL_NFSD_NUMBER}}"
    [ -n "$_configured_threads" ] || return 0

    _threads_file="${PROCFS_PATH}/fs/nfsd/threads"

    # nfsd should be running the configured number of threads.  If
    # there are a different number of threads then tell nfsd the
    # correct number.
    read _running_threads <"$_threads_file"
    # Intentionally not arithmetic comparison - avoids extra errors
    # when above fails...
    if [ "$_running_threads" != "$_configured_threads" ] ; then
        echo "Attempting to correct number of nfsd threads from ${_running_threads} to ${_configured_threads}"
        echo "$_configured_threads" >"$_threads_file"
    fi
}

##################################################
# list share directories

nfs_monitor_list_shares ()
{
    _cache_file="${CTDB_NFS_CALLOUT_STATE_DIR}/list_shares_cache"
    if  [ ! -r "$nfs_exports_file" ] || [ ! -r "$_cache_file" ] || \
            [ "$nfs_exports_file" -nt "$_cache_file" ] ; then
        mkdir -p "$CTDB_NFS_CALLOUT_STATE_DIR"
        # We could just use the contents of $nfs_exports_file.
        # However, let's regard that file as internal to NFS and use
        # exportfs, which is the public API.
        if ! _exports=$(exportfs -v) ; then
            echo "WARNING: failed to run exportfs to list NFS shares" >&2
            return
        fi

        echo "$_exports" |
            grep '^/' |
            sed -e 's@[[:space:]][[:space:]]*[^[:space:]()][^[:space:]()]*([^[:space:]()][^[:space:]()]*)$@@' |
            sort -u >"$_cache_file"
    fi

    cat "$_cache_file"
}

##################################################

nfs_register ()
{
    cat <<EOF
shutdown
startup
stop
start
monitor-list-shares
monitor-post
EOF
}

##################################################

case "$1" in
    shutdown)
        nfs_shutdown
        ;;
    startup)
        nfs_startup
        ;;
    stop)
        service_stop "$2"
        ;;
    start)
        service_start "$2"
        ;;
    monitor-list-shares)
        nfs_monitor_list_shares
        ;;
    monitor-post)
        nfs_check_thread_count
        ;;
    register)
        nfs_register
        ;;
    monitor-pre|releaseip|takeip)
        # Not required/implemented
        :
        ;;
    *)
        usage
esac