# lib/lvm
 # Configure the default LVM volume group used by Cinder and Nova
 
 # Dependencies:
 #
 # - ``functions`` file
 # - ``cinder`` configurations
 
 # DATA_DIR
 
 # clean_default_volume_group - called from clean()
 # configure_default_volume_group - called from configure()
 # init_default_volume_group - called from init()
 
 
 # Save trace setting
 MY_XTRACE=$(set +o | grep xtrace)
 set +o xtrace
 
 
 # Defaults
 # --------
 # Name of the lvm volume groups to use/create for iscsi volumes
 # This monkey-motion is for compatibility with icehouse-generation Grenade
 # If ``VOLUME_GROUP`` is set, use it, otherwise we'll build a VG name based
 # on ``VOLUME_GROUP_NAME`` that includes the backend name
 # Grenade doesn't use ``VOLUME_GROUP2`` so it is left out
 VOLUME_GROUP_NAME=${VOLUME_GROUP:-${VOLUME_GROUP_NAME:-stack-volumes}}
 DEFAULT_VOLUME_GROUP_NAME=$VOLUME_GROUP_NAME-default
 
 # Backing file name is of the form $VOLUME_GROUP$BACKING_FILE_SUFFIX
 BACKING_FILE_SUFFIX=-backing-file
 
 
 # Entry Points
 # ------------
 
 # _clean_lvm_volume_group removes all default LVM volumes
 #
 # Usage: clean_lvm_volume_group $vg
 function _clean_lvm_volume_group {
     local vg=$1
 
     # Clean out existing volumes
     sudo lvremove -f $vg
 }
 
 # _clean_lvm_backing_file() removes the backing file of the
 # volume group
 #
 # Usage: _clean_lvm_backing_file() $backing_file
 function _clean_lvm_backing_file {
     local backing_file=$1
 
     # if the backing physical device is a loop device, it was probably setup by devstack
     if [[ -n "$backing_file" ]] && [[ -e "$backing_file" ]]; then
         local vg_dev=$(sudo losetup -j $backing_file | awk -F':' '/'$BACKING_FILE_SUFFIX'/ { print $1}')
         sudo losetup -d $vg_dev
         rm -f $backing_file
     fi
 }
 
 # clean_lvm_volume_group() cleans up the volume group and removes the
 # backing file
 #
 # Usage: clean_lvm_volume_group $vg
 function clean_lvm_volume_group {
     local vg=$1
 
     _clean_lvm_volume_group $vg
     # if there is no logical volume left, it's safe to attempt a cleanup
     # of the backing file
     if [[ -z "$(sudo lvs --noheadings -o lv_name $vg 2>/dev/null)" ]]; then
         _clean_lvm_backing_file $DATA_DIR/$vg$BACKING_FILE_SUFFIX
     fi
 }
 
 
 # _create_volume_group creates default volume group
 #
 # Usage: _create_lvm_volume_group() $vg $size
 function _create_lvm_volume_group {
     local vg=$1
     local size=$2
 
     local backing_file=$DATA_DIR/$vg$BACKING_FILE_SUFFIX
     if ! sudo vgs $vg; then
         # Only create if the file doesn't already exists
         [[ -f $DATA_DIR/$backing_file ]] || truncate -s $size $backing_file
         local vg_dev=`sudo losetup -f --show $backing_file`
 
         # Only create volume group if it doesn't already exist
         if ! sudo vgs $vg; then
             sudo vgcreate $vg $vg_dev
         fi
     fi
 }
 
 # init_lvm_volume_group() initializes the volume group creating the backing
 # file if necessary
 #
 # Usage: init_lvm_volume_group() $vg
 function init_lvm_volume_group {
     local vg=$1
     local size=$2
     # Start with a clean volume group
     _create_lvm_volume_group $vg $size
 
     if is_fedora || is_suse; then
         # service is not started by default
         start_service tgtd
     fi
 
     # Remove iscsi targets
     sudo tgtadm --op show --mode target | grep Target | cut -f3 -d ' ' | sudo xargs -n1 tgt-admin --delete || true
 
     _clean_lvm_volume_group $vg
 }
 
 # Restore xtrace
 $MY_XTRACE
 
 # mode: shell-script
 # End: