thin: fix component detection of external origin

When check active componet of thinLV with external origin,
we need to check if the external origin isn't already active.
For this however we need to use layered check for -real device.

WHATS_NEW

@@ -1,5 +1,6 @@
 Version 2.03.13 - 
 ===============================
+  Fix detection of active components of external origin volume.
   Add vdoimport tool to support conversion of VDO volumes.
   Support configurable allocation/vdo_pool_header_size.
   Fix handling of lvconvert --type vdo-pool --virtualsize.

lib/activate/activate.c

@@ -2740,7 +2740,10 @@ static int _component_cb(struct logical_volume *lv, void *data)
 	    (lv_is_thin_pool(lv) && pool_is_active(lv)))
 		return -1;
 
-	if (lv_is_active(lv)) {
+	/* External origin is activated through thinLV and uses -real suffix.
+	 * Note: for old clustered logic we would need to check for all thins */
+	if ((lv_is_external_origin(lv) && lv_info(lv->vg->cmd, lv, 1, NULL, 0, 0)) ||
+	    lv_is_active(lv)) {
 		if (!lv_is_component(lv) || lv_is_visible(lv))
 			return -1;	/* skip whole subtree */
 

test/shell/lvconvert-cache-thin.sh

@@ -67,4 +67,26 @@ fail lvconvert --yes --thinpool $vg/$lv1 --poolmetadata $vg/$lv
 # Thin-pool CAN use cached data LV
 lvconvert --yes --thinpool $vg/$lv
 
+lvremove -f $vg
+
+# Check we can active snapshot of cached external origin (BZ: 1967744)
+lvcreate -T -L10M $vg/pool "$dev1"
+
+lvcreate -L10M -n origin $vg "$dev1"
+lvcreate -H -L4M -n CPOOL $vg/origin "$dev2"
+
+# Use cached origin as external origin
+lvconvert -y -T --thinpool $vg/pool --originname extorig origin
+
+# Check we can easily create snapshot of such LV
+lvcreate -y -kn -n snap -s $vg/origin
+
+# Deactivate everything and do a component activation of _cmeta volume
+lvchange -an $vg
+lvchange -ay -y $vg/CPOOL_cpool_cmeta
+
+# Now this must fail since component volume is active
+not lvcreate -y -kn -n snap2 -s $vg/origin |& tee err
+grep "cmeta is active" err
+
 vgremove -f $vg