X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?a=blobdiff_plain;f=backup%2Fsnap-common;h=f6e788ab975a566f1c5dcad9ce4b17297eea798e;hb=a03c623bb1574922308347df36cd57c85e72981a;hp=c12bc6dcbbbafae0949efde85e7b15f02fec84ff;hpb=b7fed73a8d9509acef0307ce94d59c047653b821;p=chiark-utils.git

diff --git a/backup/snap-common b/backup/snap-common
index c12bc6d..f6e788a 100644
--- a/backup/snap-common
+++ b/backup/snap-common
@@ -29,6 +29,27 @@ esac
 
 #---------- common functions
 
+lvmunmapperdevice () {
+	# turns device=/dev/mapper/... into /dev/<group>/<volume>
+	case "$device" in
+	/dev/mapper/*)
+		device="`printf '%s' "$device" | perl -pe '
+			s,^/dev/mapper/,,;
+			die if m,/,;
+			s,\-\-,!,g;
+			s,\-,/,g;
+			s,\!,-,g;
+			s,^,/dev/,;
+		'`"
+		;;
+	esac
+}
+
+lvmdevice2vgroup () {
+	vgroup="${device#/dev/}"
+	vgroup="${vgroup%/*}"
+}
+
 lvmdropcore () {
 	snmnt="$vardir/snap-mount"
 	umount -v "$snmnt" || true
@@ -49,6 +70,7 @@ lvmdropcore () {
 }
 
 lvmextentscore1 () {
+	# vgroup must be set
 	vgdisplay_out="$(really vgdisplay -c "$vgroup")"
 	extents="$(printf "%s" "$vgdisplay_out" | awk -F: '{print $16}')"
 	extsize="$(printf "%s" "$vgdisplay_out" | awk -F: '{print $13}')"
@@ -60,6 +82,7 @@ lvmextentscore2 () {
 }
 
 lvmcreatecore1 () {
+	# vgroup must be set
 	lvpath="/dev/$vgroup/$lvm_lv"
 	ln -s -- "$lvpath" "$vardir"/snap-device
 	sync