Move functionality from lvconvert_merge (the command handler) into separate
functions lvconvert_check_merge and lvconvert_do_merge.

This is needed to cleanly implement merge-on-activate.

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

---
 tools/lvconvert.c |   47 ++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 38 insertions(+), 9 deletions(-)

Index: LVM2.2.02.39/tools/lvconvert.c
===================================================================
--- LVM2.2.02.39.orig/tools/lvconvert.c	2008-08-04 20:42:45.000000000 +0200
+++ LVM2.2.02.39/tools/lvconvert.c	2008-08-04 20:42:48.000000000 +0200
@@ -800,20 +800,19 @@ static void swap_lvids(struct logical_vo
 	lv2->minor = n;
 }
 
-static int lvconvert_merge(struct cmd_context *cmd,
-			   struct logical_volume *lv,
-			   struct lvconvert_params *lp)
+static int lvconvert_check_merge(struct cmd_context *cmd,
+				 struct logical_volume *lv,
+				 int type)
 {
 	struct logical_volume *origin = origin_from_cow(lv);
 	struct lv_segment *cow_seg = find_cow(lv);
 	struct lvinfo info;
-	char *new_name;
-	const char *lv_name;
 
 	if (cow_seg->status & SNAPSHOT_MERGE) {
 		log_error("Snapshot %s is already merging", lv->name);
 		return 0;
 	}
+
 	if (origin->merging_snapshot) {
 		log_error("Another snapshot is already merging");
 		return 0;
@@ -825,23 +824,34 @@ static int lvconvert_merge(struct cmd_co
 			return 0;
 		}
 	}
+
 	if (lv_info(cmd, lv, &info, 1, 0)) {
-		if (info.open_count && lp->merge != MERGE_AS_SNAPSHOT) {
+		if (info.open_count && type != MERGE_AS_SNAPSHOT) {
 			log_error("Can't merge when snapshot is open");
 			return 0;
 		}
 	}
-	if (origin->origin_count != 1 && lp->merge == MERGE_AS_SNAPSHOT) {
+	if (origin->origin_count != 1 && type == MERGE_AS_SNAPSHOT) {
 		log_error("There must not be other snapshots when preserving snapshot name");
 		return 0;
 	}
 
-	lv_name = lv->name;
+	return 1;
+}
+
+static int lvconvert_do_merge(struct cmd_context *cmd,
+			      struct logical_volume *lv,
+			      int type)
+{
+	struct logical_volume *origin = origin_from_cow(lv);
+	struct lv_segment *cow_seg = find_cow(lv);
+	char *new_name;
+	const char *lv_name;
 
 	cow_seg->status |= SNAPSHOT_MERGE;
 	origin->merging_snapshot = cow_seg;
 
-	if (lp->merge == MERGE_AS_SNAPSHOT)
+	if (type == MERGE_AS_SNAPSHOT)
 		swap_lvids(origin, lv);
 
 	new_name = dm_pool_alloc(cmd->mem, NAME_LEN);
@@ -849,6 +859,7 @@ static int lvconvert_merge(struct cmd_co
 		log_error("Failed to allocate memory for the new name");
 		return 0;
 	}
+
 	if (!generate_lv_name(lv->vg, "snapshot%d", new_name, NAME_LEN)) {
 		log_error("Failed to generate unique name for the new volume");
 		return 0;
@@ -882,6 +893,24 @@ static int lvconvert_merge(struct cmd_co
 		return 0;
 	}
 
+	return 1;
+}
+
+static int lvconvert_merge(struct cmd_context *cmd,
+			   struct logical_volume *lv,
+			   struct lvconvert_params *lp)
+{
+	struct logical_volume *origin = origin_from_cow(lv);
+	const char *lv_name;
+
+	if (!lvconvert_check_merge(cmd, lv, lp->merge))
+		return 0;
+
+	lv_name = lv->name;
+
+	if (!lvconvert_do_merge(cmd, lv, lp->merge))
+		return 0;
+
 	lp->need_polling = 1;
 	lp->lv_to_poll = origin;