backup/snap-common

   1 # sourced by snap/lvm and snap/remountrocp
   2
   3 #---------- common arg parsing
   4
   5 nargs=$#
   6 opmode="$1"
   7 vardir="$2"
   8 device="$3"
   9 mountpoint="$4"
  10
  11 lvm_lv=chiark-backup
  12 lvm_lvtools_opts='-A n'
  13 lvm_lvcreate_opts=
  14 lvm_lvcreate_args=
  15
  16 test ! -f /etc/chiark-backup/settings.sh || . /etc/chiark-backup/settings.sh
  17
  18 case "$nargs.$opmode" in
  19 4.snap|2.drop)
  20         ;;
  21 *)
  22         cat >&2 <<END
  23 usage: .../$snapkind snap VARDIR DEV MOUNT
  24        .../$snapkind drop VARDIR
  25 END
  26         exit 1
  27         ;;
  28 esac
  29
  30 #---------- common functions
  31
  32 lvmunmapperdevice () {
  33         # turns device=/dev/mapper/... into /dev/<group>/<volume>
  34         case "$device" in
  35         /dev/mapper/*)
  36                 device="`printf '%s' "$device" | perl -pe '
  37                         s,^/dev/mapper/,,;
  38                         die if m,/,;
  39                         s,\-\-,!,g;
  40                         s,\-,/,g;
  41                         s,\!,-,g;
  42                         s,^,/dev/,;
  43                 '`"
  44                 ;;
  45         esac
  46 }
  47
  48 lvmdevice2vgroup () {
  49         vgroup="${device#/dev/}"
  50         vgroup="${vgroup%/*}"
  51 }
  52
  53 lvmdropcore () {
  54         snmnt="$vardir/snap-mount"
  55         umount -v "$snmnt" || true
  56         test ! -d "$snmnt" || rmdir -- "$snmnt" || rm -f "$snmnt"
  57
  58         set +e
  59         old_lv_dev="$(readlink $vardir/snap-device)"
  60         rc=$?
  61         set -e
  62
  63         if [ $rc = 0 ]; then
  64                 set +e
  65                 lvremove -f $lvm_lvtools_opts      $old_lv_dev
  66                 set -e
  67                 rm $vardir/snap-device
  68         fi
  69 }
  70
  71 lvmextentscore1 () {
  72         # vgroup must be set
  73         vgdisplay_out="$(really vgdisplay -c "$vgroup")"
  74         extents="$(printf "%s" "$vgdisplay_out" | awk -F: '{print $16}')"
  75         extsize="$(printf "%s" "$vgdisplay_out" | awk -F: '{print $13}')"
  76 }
  77
  78 lvmextentscore2 () {
  79         if [ $extents2 -lt $extents ]; then extents=$extents2; fi
  80         lvm_lvsize_opts="-l $extents"
  81 }
  82
  83 lvmcreatecore1 () {
  84         # vgroup must be set
  85         lvpath="/dev/$vgroup/$lvm_lv"
  86         ln -s -- "$lvpath" "$vardir"/snap-device
  87         sync
  88 }