From e8a40f65712630fbcc1a0bbcef5a415eb25e8f94 Mon Sep 17 00:00:00 2001
From: Zdenek Kabelac <zkabelac@redhat.com>
Date: Fri, 18 Nov 2011 19:22:49 +0000
Subject: [PATCH] Allow to activate snapshot

Add extra code to active and deactivate related
snapshots and origin when user specifies snapshot
logical volume as lvchange parameter.

Before patch:

$> lvs -a
  LV    VG   Attr     LSize  Pool Origin Snap%  Move Log Copy%  Convert
  lvol0 mvg  owi-a-s-  1.00k
  lvol1 mvg  swi-a-s- 16.00k      lvol0    0.00
  lvol2 mvg  swi-a-s- 16.00k      lvol0    0.00

$> lvchange -an mvg/lvol2; echo $?
  Can't change snapshot logical volume "lvol2".
5

After patch:

$> lvchange -an mvg/lvol2
Change of snapshot lvol2 will also change its origin lvol0 and 1 other
snapshot(s). Proceed? [y/n]: n
  Logical volume lvol2 not changed.

$> lvchange -y -an mvg/lvol2; echo $?
0

$> lvs -a
  LV    VG   Attr     LSize  Pool Origin Snap%  Move Log Copy%  Convert
  lvol0 mvg  owi---s-  1.00k
  lvol1 mvg  swi---s- 16.00k      lvol0
  lvol2 mvg  swi---s- 16.00k      lvol0
---
 WHATS_NEW        |  3 ++-
 tools/lvchange.c | 27 ++++++++++++++++++++++-----
 2 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/WHATS_NEW b/WHATS_NEW
index 90f35b8ed..27c15ca14 100644
--- a/WHATS_NEW
+++ b/WHATS_NEW
@@ -1,6 +1,7 @@
 Version 2.02.89 - 
 ==================================
-  Skip non-virtual origins for availability change for lvchange.
+  Allow changing availability state of snapshots.
+  Skip non-virtual snapshots for availability change for lvchange with vg name.
   Adjusted mirror region size only for mirrors and raids.
   Reorder prompt conditions for removal of active volumes.
   Avoid 'mda inconsistency' by properly registering UNLABELLED_PV flag (2.02.86).
diff --git a/tools/lvchange.c b/tools/lvchange.c
index 6cb918539..2a99c455b 100644
--- a/tools/lvchange.c
+++ b/tools/lvchange.c
@@ -1,6 +1,6 @@
 /*
  * Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
- * Copyright (C) 2004-2007 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2004-2011 Red Hat, Inc. All rights reserved.
  *
  * This file is part of LVM2.
  *
@@ -125,6 +125,9 @@ static int lvchange_availability(struct cmd_context *cmd,
 
 	activate = arg_uint_value(cmd, available_ARG, 0);
 
+	if (lv_is_cow(lv) && !lv_is_virtual_origin(origin_from_cow(lv)))
+		lv = origin_from_cow(lv);
+
 	if (activate == CHANGE_ALN) {
 		log_verbose("Deactivating logical volume \"%s\" locally",
 			    lv->name);
@@ -515,6 +518,7 @@ static int lvchange_single(struct cmd_context *cmd, struct logical_volume *lv,
 	int doit = 0, docmds = 0;
 	int dmeventd_mode, archived = 0;
 	struct logical_volume *origin;
+	char snaps_msg[128];
 
 	if (!(lv->vg->status & LVM_WRITE) &&
 	    (arg_count(cmd, contiguous_ARG) || arg_count(cmd, permission_ARG) ||
@@ -534,11 +538,24 @@ static int lvchange_single(struct cmd_context *cmd, struct logical_volume *lv,
 		return ECMD_FAILED;
 	}
 
-	if (lv_is_cow(lv) && !lv_is_virtual_origin(origin_from_cow(lv)) &&
+	if (lv_is_cow(lv) && !lv_is_virtual_origin(origin = origin_from_cow(lv)) &&
 	    arg_count(cmd, available_ARG)) {
-		log_error("Can't change snapshot logical volume \"%s\"",
-			  lv->name);
-		return ECMD_FAILED;
+		if (origin->origin_count < 2)
+			snaps_msg[0] = '\0';
+		else if (dm_snprintf(snaps_msg, sizeof(snaps_msg),
+				     " and %u other snapshot(s)",
+				     origin->origin_count - 1) < 0) {
+			log_error("Failed to prepare message.");
+			return ECMD_FAILED;
+		}
+
+		if (!arg_count(cmd, yes_ARG) &&
+		    (yes_no_prompt("Change of snapshot %s will also change its"
+				   " origin %s%s. Proceed? [y/n]: ", lv->name,
+				   origin->name, snaps_msg) == 'n')) {
+			log_error("Logical volume %s not changed.", lv->name);
+			return ECMD_FAILED;
+		}
 	}
 
 	if (lv->status & PVMOVE) {
-- 
2.43.5