Activate origin LV as snapshot-merge target and don't activate merging snapshot
at all. Using snapshot-origin target would be pointless because the origin
contains volatile data while merging is in progress.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

---
 lib/activate/dev_manager.c |   33 +++++++++++++++++++++++----------
 tools/lvconvert.c          |    6 ++++++
 2 files changed, 29 insertions(+), 10 deletions(-)

Index: LVM2.2.02.39/lib/activate/dev_manager.c
===================================================================
--- LVM2.2.02.39.orig/lib/activate/dev_manager.c	2008-07-11 22:26:14.000000000 +0200
+++ LVM2.2.02.39/lib/activate/dev_manager.c	2008-07-11 22:26:33.000000000 +0200
@@ -749,13 +749,20 @@ static int _add_origin_target_to_dtree(s
 					 struct dm_tree_node *dnode,
 					 struct logical_volume *lv)
 {
-	const char *real_dlid;
+	const char *real_dlid, *cow_dlid;
 
 	if (!(real_dlid = build_dlid(dm, lv->lvid.s, "real")))
 		return_0;
 
-	if (!dm_tree_node_add_snapshot_origin_target(dnode, lv->size, real_dlid))
-		return_0;
+	if (!lv->merging_snapshot) {
+		if (!dm_tree_node_add_snapshot_origin_target(dnode, lv->size, real_dlid))
+			return_0;
+	} else {
+		if (!(cow_dlid = build_dlid(dm, lv->merging_snapshot->cow->lvid.s, "cow")))
+			return_0;
+		if (!dm_tree_node_add_snapshot_merge_target(dnode, lv->size, real_dlid, cow_dlid, lv->merging_snapshot->chunk_size))
+			return_0;
+	}
 
 	return 1;
 }
@@ -774,6 +781,10 @@ static int _add_snapshot_target_to_dtree
 		return 0;
 	}
 
+	if (snap_seg->status & SNAPSHOT_MERGE) {
+		return 1;
+	}
+
 	if (!(origin_dlid = build_dlid(dm, snap_seg->origin->lvid.s, "real")))
 		return_0;
 
@@ -782,13 +793,8 @@ static int _add_snapshot_target_to_dtree
 
 	size = (uint64_t) snap_seg->len * snap_seg->origin->vg->extent_size;
 
-	if (!(snap_seg->status & SNAPSHOT_MERGE)) {
-		if (!dm_tree_node_add_snapshot_target(dnode, size, origin_dlid, cow_dlid, 1, snap_seg->chunk_size))
-			return_0;
-	} else {
-		if (!dm_tree_node_add_snapshot_merge_target(dnode, size, origin_dlid, cow_dlid, snap_seg->chunk_size))
-			return_0;
-	}
+	if (!dm_tree_node_add_snapshot_target(dnode, size, origin_dlid, cow_dlid, 1, snap_seg->chunk_size))
+		return_0;
 
 	return 1;
 }
@@ -850,6 +856,10 @@ static int _add_segment_to_dtree(struct 
 			log_error("Clustered snapshots are not yet supported");
 			return 0;
 		}
+		if (seg->lv->merging_snapshot) {
+			if (!_add_new_lv_to_dtree(dm, dtree, seg->lv->merging_snapshot->cow, "cow"))
+				return_0;
+		}
 		if (!_add_new_lv_to_dtree(dm, dtree, seg->lv, "real"))
 			return_0;
 	} else if (lv_is_cow(seg->lv) && !layer) {
@@ -893,6 +903,9 @@ static int _add_new_lv_to_dtree(struct d
 	uint32_t read_ahead = lv->read_ahead;
 	uint32_t read_ahead_flags = UINT32_C(0);
 
+	if (lv_is_cow(lv) && find_cow(lv)->status & SNAPSHOT_MERGE && !layer)
+		return 1;
+
 	if (!(name = build_dm_name(dm->mem, lv->vg->name, lv->name, layer)))
 		return_0;
 
Index: LVM2.2.02.39/tools/lvconvert.c
===================================================================
--- LVM2.2.02.39.orig/tools/lvconvert.c	2008-07-11 22:26:24.000000000 +0200
+++ LVM2.2.02.39/tools/lvconvert.c	2008-07-11 22:26:33.000000000 +0200
@@ -734,6 +734,12 @@ static int lvconvert_merge(struct cmd_co
 		return 0;
 	}
 
+	if (!deactivate_lv(cmd, lv)) {
+		log_error("Failed to deactivate merging snapshot %s", lv->name);
+		vg_revert(lv->vg);
+		return 0;
+	}
+
 	if (!vg_commit(lv->vg))
 		return_0;