mount_storage()
{
    echo "* Probing storage..."

    bdev="$1"
    if ! [ -b "$bdev" ]; then
        echo "* Device $bdev does not exist."
        return 1
    fi

    mount -o rw,relatime "$bdev" "$cfg_lauv_storage_dir" 2> /dev/null

    if [ $? -ne 0 ]; then
        echo "* Failed to mount $bdev on $cfg_lauv_storage_dir"
        return 1
    fi

    echo "* Mounted '$bdev' on '$cfg_lauv_storage_dir'"
    return 0
}

try_mount_storage()
{
    n=0; while [ $n -lt 30 ]; do
             mount_storage "$1"

             if [ $? -eq 0 ]; then
                 return 0
             fi

             sleep 1
             let n++
         done

    return 1
}

start_nfs_server()
{
    echo "* Creating NFS administrative folder..."
    mkdir -p /var/lib/nfs
    if ! [ -d /var/lib/nfs ]; then
        echo "ERROR: failed to create data folder."
        return 1
    fi

    echo "* Launching rpcbind..."
    /usr/bin/rpcbind
    if [ $? -ne 0 ]; then
        echo "ERROR: failed to start rpcbind."
        return 1
    fi

    echo "* Launching rpc.statd..."
    /usr/bin/rpc.statd
    if [ $? -ne 0 ]; then
        echo "ERROR: failed to start rpc.statd."
        return 1
    fi

    echo "* Launching rpc.nfsd..."
    /usr/bin/rpc.nfsd
    if [ $? -ne 0 ]; then
        echo "ERROR: failed to start rpc.nfsd."
        return 1
    fi

    echo "* Creating NFS filesystem table..."
    /usr/bin/exportfs -ra
    if [ $? -ne 0 ]; then
        echo "ERROR: failed to create filesystem table."
        return 1
    fi

    echo "* Launching rpc.mountd..."
    /usr/bin/rpc.mountd
    if [ $? -ne 0 ]; then
        echo "ERROR: failed to start rpc.mountd."
        return 1
    fi

    echo "* Exporting NFS filesystems..."
    /usr/bin/exportfs \
        -o rw,async,no_root_squash,no_subtree_check \
        10.0.0.0/16:"$cfg_lauv_storage_dir"
    if [ $? -ne 0 ]; then
        echo "ERROR: failed to export filesystems."
        return 1
    fi
}

stop_nfs_server()
{
    echo "* Unexporting NFS filesystems..."
    exportfs -au
    echo "* Terminating rpc.mountd..."
    killall rpc.mountd 2> /dev/null
    echo "* Terminating rpc.statd..."
    killall rpc.statd 2> /dev/null
    echo "* Terminating rpc.bind..."
    killall rpcbind 2> /dev/null
}

start()
{
    mkdir -p "$cfg_lauv_storage_dir"

    # Removable storage.
    if [ "$cfg_lauv_storage" != "internal" ]; then
        try_mount_storage /dev/sda1
    fi

    # FIXME: what to do if the above fails.
    start_nfs_server
}

stop()
{
    stop_nfs_server

    if [ "$cfg_lauv_storage" != "internal" ]; then
        echo "* Unmounting storage..."
        umount "$cfg_lauv_storage_dir"
    fi
}