Test that all snapshots are not open before we deactivate volume.

This prevents very weird misbehavior when we have closed origin, open snapshot
and deactivate the origin with lvchange -an or vgchange -an command --- the
origin is closed, the snapshot remains open and cannot be deactivated.

There is still race condition if the snapshot is open immediatelly after the
test, but it is inevitable --- and the patch prevents misbehavior in most common
case.

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

---
 lib/activate/activate.c |   23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

Index: LVM2.2.02.48/lib/activate/activate.c
===================================================================
--- LVM2.2.02.48.orig/lib/activate/activate.c	2009-06-01 14:43:32.000000000 +0200
+++ LVM2.2.02.48/lib/activate/activate.c	2009-07-08 17:37:47.000000000 +0200
@@ -1001,10 +1001,25 @@ int lv_deactivate(struct cmd_context *cm
 		goto out;
 	}
 
-	if (info.open_count && lv_is_visible(lv)) {
-		log_error("LV %s/%s in use: not deactivating", lv->vg->name,
-			  lv->name);
-		goto out;
+	if (lv_is_visible(lv)) {
+		if (info.open_count) {
+			log_error("LV %s/%s in use: not deactivating", lv->vg->name,
+				  lv->name);
+			goto out;
+		}
+		if (lv_is_origin(lv)) {
+			struct lv_segment *snap_seg;
+			dm_list_iterate_items_gen(snap_seg, &lv->snapshot_segs, origin_list) {
+				struct logical_volume *snap = snap_seg->cow;
+				if (!lv_info(cmd, snap, &info, 1, 0))
+					goto out;
+
+				if (info.exists && info.open_count) {
+					log_error("LV %s/%s has open snapshot %s: not deactivating", lv->vg->name, lv->name, snap->name);
+					goto out;
+				}
+			}
+		}
 	}
 
 	lv_calculate_readahead(lv, NULL);