From 8e8baf89c0627e8eaacc44713f01a09b84bd0f3e Mon Sep 17 00:00:00 2001
From: Dave Wysochanski <dwysocha@redhat.com>
Date: Wed, 23 Apr 2008 14:33:06 +0000
Subject: [PATCH] Fix vgsplit internal counting of snapshot LVs.

---
 WHATS_NEW                        |  1 +
 lib/metadata/metadata-exported.h | 18 +++++++++++++++++-
 tools/vgsplit.c                  |  2 +-
 3 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/WHATS_NEW b/WHATS_NEW
index 0a2a3bb06..dc2d7d471 100644
--- a/WHATS_NEW
+++ b/WHATS_NEW
@@ -1,5 +1,6 @@
 Version 2.02.36 - 
 =================================
+  Fix vgsplit internal counting of snapshot LVs.
   Fix internal snapshot_count when vgmerge with snapshots in source VG.
   Simply clvmd-openais by using non-async saLckResourceLock.
   Check lv_count in vg_validate.
diff --git a/lib/metadata/metadata-exported.h b/lib/metadata/metadata-exported.h
index dd04e5f6c..a3c89f6ae 100644
--- a/lib/metadata/metadata-exported.h
+++ b/lib/metadata/metadata-exported.h
@@ -202,7 +202,23 @@ struct volume_group {
 	uint32_t pv_count;
 	struct list pvs;
 
-	/* logical volumes */
+	/*
+	 * logical volumes
+	 * The following relationship should always hold:
+	 * list_size(lvs) = lv_count + 2 * snapshot_count
+	 *
+	 * Snapshots consist of 2 instances of "struct logical_volume":
+	 * - cow (lv_name is visible to the user)
+	 * - snapshot (lv_name is 'snapshotN')
+	 * Neither of these instances is reflected in lv_count, but we
+	 * multiply the snapshot_count by 2.
+	 *
+	 * Mirrors consist of multiple instances of "struct logical_volume":
+	 * - one for the mirror log
+	 * - one for each mirror leg
+	 * - one for the user-visible mirror LV
+	 * all of the instances are reflected in lv_count.
+	 */
 	uint32_t lv_count;
 	uint32_t snapshot_count;
 	struct list lvs;
diff --git a/tools/vgsplit.c b/tools/vgsplit.c
index c0cb47632..50999281a 100644
--- a/tools/vgsplit.c
+++ b/tools/vgsplit.c
@@ -109,7 +109,7 @@ static int _move_one_lv(struct volume_group *vg_from,
 	if (lv->status & SNAPSHOT) {
 		vg_from->snapshot_count--;
 		vg_to->snapshot_count++;
-	} else {
+	} else if (!lv_is_cow(lv)) {
 		vg_from->lv_count--;
 		vg_to->lv_count++;
 	}