From 442dbf9ad8c6f107a7ffe948f60ed22395e8ffbe Mon Sep 17 00:00:00 2001
From: Zdenek Kabelac <zkabelac@redhat.com>
Date: Thu, 10 Mar 2011 14:40:32 +0000
Subject: [PATCH] Refactor code for _lv_postoder

Add _lv_postorder_vg() - for calling _lv_postorder() for every LV from VG.
We use this in 2 places -  vg_mark_partial_lvs() and vg_validate()
so make it as a one function.

Benefit here is - to use only one cleanup code and avoid
potentially duplicate scans of same LVs.
---
 WHATS_NEW               |  1 +
 lib/metadata/metadata.c | 43 +++++++++++++++++++++++++++--------------
 2 files changed, 29 insertions(+), 15 deletions(-)

diff --git a/WHATS_NEW b/WHATS_NEW
index 070b45931..d60f22668 100644
--- a/WHATS_NEW
+++ b/WHATS_NEW
@@ -1,5 +1,6 @@
 Version 2.02.85 - 
 ===================================
+  Add _lv_postorder_vg() to improve efficiency for all LVs in VG.
   Use hash tables to speedup string search in validate_vg().
   Refactor allocation of VG structure, add alloc_vg().
   Avoid possible endless loop in _free_vginfo when 4 or more VGs have same name.
diff --git a/lib/metadata/metadata.c b/lib/metadata/metadata.c
index b95c144ac..c61c91615 100644
--- a/lib/metadata/metadata.c
+++ b/lib/metadata/metadata.c
@@ -2039,6 +2039,29 @@ static int _lv_postorder(struct logical_volume *lv,
 	return r;
 }
 
+/*
+ * Calls _lv_postorder() on each LV from VG. Avoids duplicate transitivity visits.
+ * Clears with _lv_postorder_cleanup() when all LVs were visited by postorder.
+ */
+static int _lv_postorder_vg(struct volume_group *vg,
+			    int (*fn)(struct logical_volume *lv, void *data),
+			    void *data)
+{
+	struct lv_list *lvl;
+	int r = 1;
+
+	dm_list_iterate_items(lvl, &vg->lvs)
+		if (!_lv_postorder_visit(lvl->lv, fn, data)) {
+			stack;
+			r = 0;
+		}
+
+	dm_list_iterate_items(lvl, &vg->lvs)
+		_lv_postorder_cleanup(lvl->lv, 0);
+
+	return r;
+}
+
 struct _lv_mark_if_partial_baton {
 	int partial;
 };
@@ -2076,11 +2099,6 @@ static int _lv_mark_if_partial_single(struct logical_volume *lv, void *data)
 	return 1;
 }
 
-static int _lv_mark_if_partial(struct logical_volume *lv)
-{
-	return _lv_postorder(lv, _lv_mark_if_partial_single, NULL);
-}
-
 /*
  * Mark LVs with missing PVs using PARTIAL_LV status flag. The flag is
  * propagated transitively, so LVs referencing other LVs are marked
@@ -2088,14 +2106,9 @@ static int _lv_mark_if_partial(struct logical_volume *lv)
  */
 int vg_mark_partial_lvs(struct volume_group *vg)
 {
-	struct logical_volume *lv;
-	struct lv_list *lvl;
+	if (!_lv_postorder_vg(vg, _lv_mark_if_partial_single, NULL))
+		return_0;
 
-	dm_list_iterate_items(lvl, &vg->lvs) {
-		lv = lvl->lv;
-		if (!_lv_mark_if_partial(lv))
-			return_0;
-	}
 	return 1;
 }
 
@@ -2378,9 +2391,9 @@ int vg_validate(struct volume_group *vg)
 	dm_hash_destroy(lvname_hash);
 	dm_hash_destroy(lvid_hash);
 
-	dm_list_iterate_items(lvl, &vg->lvs) {
-		if (!_lv_postorder(lvl->lv, _lv_validate_references_single, NULL))
-			r = 0;
+	if (!_lv_postorder_vg(vg, _lv_validate_references_single, NULL)) {
+		stack;
+		r = 0;
 	}
 
 	dm_list_iterate_items(lvl, &vg->lvs) {