[lvm-devel] master - cache: support vgsplit

[Zdenek Kabelac]

Gitweb:        https://sourceware.org/git/?p=lvm2.git;a=commitdiff;h=030c39073e69d51da7cdbabb78c2c544ed85f1ef
Commit:        030c39073e69d51da7cdbabb78c2c544ed85f1ef
Parent:        1cc690e911f3caa1252cac6e19488345a0a1a4bc
Author:        Zdenek Kabelac <zkabelac at redhat.com>
AuthorDate:    Fri Feb 1 21:29:22 2019 +0100
Committer:     Zdenek Kabelac <zkabelac at redhat.com>
CommitterDate: Wed Mar 20 14:38:02 2019 +0100

cache: support vgsplit

Enable vgsplit to work with VG containing cached LVs.
---
 WHATS_NEW       |    1 +
 tools/vgsplit.c |   85 ++++++++++++++++++++++++-------------------------------
 2 files changed, 38 insertions(+), 48 deletions(-)

diff --git a/WHATS_NEW b/WHATS_NEW
index ad92827..5ffef3b 100644
--- a/WHATS_NEW
+++ b/WHATS_NEW
@@ -1,5 +1,6 @@
 Version 2.03.02 - 
 ===================================
+  Add support for vgsplit with cached devices.
   Query mpath device only once per command for its state.
   Use device INFO instead of STATUS when checking for mpath device uuid.
   Change default io_memory_size from 4 to 8 MiB.
diff --git a/tools/vgsplit.c b/tools/vgsplit.c
index 7150570..e931a5c 100644
--- a/tools/vgsplit.c
+++ b/tools/vgsplit.c
@@ -1,6 +1,6 @@
 /*
  * Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
- * Copyright (C) 2004-2009,2016 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2004-2019 Red Hat, Inc. All rights reserved.
  *
  * This file is part of LVM2.
  *
@@ -384,71 +384,60 @@ static int _move_cache(struct volume_group *vg_from,
 
 	dm_list_iterate_safe(lvh, lvht, &vg_from->lvs) {
 		lv = dm_list_item(lvh, struct lv_list)->lv;
-		data = meta = orig = NULL;
 		seg = first_seg(lv);
 
 		if (!lv_is_cache(lv) && !lv_is_cache_pool(lv))
 			continue;
 
-		/*
-		 * FIXME: The code seems to move cache LVs fine, but it
-		 *        hasn't been well tested and it causes problems
-		 *        when just splitting PVs that don't contain
-		 *        cache LVs.
-		 * Waiting for next release before fixing and enabling.
-		 */
-		log_error("Unable to split VG while it contains cache LVs");
-		return 0;
-
-		/* NOTREACHED */
-
 		if (lv_is_cache(lv) && lv_is_cache_vol(seg->pool_lv)) {
 			log_error("Cannot split while LV %s has cache attached.", display_lvname(lv));
 			return 0;
-		} else if (lv_is_cache(lv)) {
-			orig = seg_lv(seg, 0);
-			data = seg_lv(first_seg(seg->pool_lv), 0);
-			meta = first_seg(seg->pool_lv)->metadata_lv;
-			/* Ensure all components are coming along */
-			is_moving = _lv_is_in_vg(vg_to, orig);
-		} else {
-			if (!dm_list_empty(&seg->lv->segs_using_this_lv) &&
-			    !(cache_seg = get_only_segment_using_this_lv(seg->lv)))
-				return_0;
-			orig = seg_lv(cache_seg, 0);
-			data = seg_lv(seg, 0);
-			meta = seg->metadata_lv;
+		}
 
-			if (_lv_is_in_vg(vg_to, data) ||
-			    _lv_is_in_vg(vg_to, meta))
-				is_moving = 1;
+		if (lv_is_cache(lv)) {
+			orig = seg_lv(seg, 0);
+			seg = first_seg(seg->pool_lv);
+		} else { /* lv_is_cache_pool */
+			orig = NULL;
+			if (!dm_list_empty(&seg->lv->segs_using_this_lv)) {
+				if (!(cache_seg = get_only_segment_using_this_lv(seg->lv)))
+					return_0;
+				orig = seg_lv(cache_seg, 0);
+			}
 		}
 
-		if (!lv_is_on_pvs(data, &vg_to->pvs))
-			continue;
+		data = seg_lv(seg, 0);
+		meta = seg->metadata_lv;
 
-		if (!lv_is_on_pvs(meta, &vg_to->pvs))
+		if ((orig && !lv_is_on_pvs(orig, &vg_to->pvs)) &&
+		    !lv_is_on_pvs(data, &vg_to->pvs) &&
+		    !lv_is_on_pvs(meta, &vg_to->pvs))
 			continue;
 
-		if (orig && (_lv_is_in_vg(vg_to, orig) != is_moving)) {
-			log_error("Can't split %s and its origin (%s)"
-				  " into separate VGs", lv->name, orig->name);
-			return 0;
-		}
+		/* Ensure all components are coming along */
+		if (orig) {
+			is_moving = _lv_is_in_vg(vg_to, orig);
 
-		if (data && (_lv_is_in_vg(vg_to, data) != is_moving)) {
-			log_error("Can't split %s and its cache pool"
-				  " data LV (%s) into separate VGs",
-				  lv->name, data->name);
-			return 0;
-		}
+			if (_lv_is_in_vg(vg_to, data) != is_moving) {
+				log_error("Cannot split cache origin %s and its cache pool data %s "
+					  "into separate VGs.",
+					  display_lvname(orig), display_lvname(data));
+				return 0;
+			}
 
-		if (meta && (_lv_is_in_vg(vg_to, meta) != is_moving)) {
-			log_error("Can't split %s and its cache pool"
-				  " metadata LV (%s) into separate VGs",
-				  lv->name, meta->name);
+			if (_lv_is_in_vg(vg_to, meta) != is_moving) {
+				log_error("Cannot split cache origin %s and its cache pool metadata %s "
+					  "into separate VGs.",
+					  display_lvname(orig), display_lvname(meta));
+				return 0;
+			}
+		} else if (_lv_is_in_vg(vg_to, data) != _lv_is_in_vg(vg_to, meta)) {
+			log_error("Cannot split cache pool data %s and its metadata %s "
+				  "into separate VGs.",
+				  display_lvname(data), display_lvname(meta));
 			return 0;
 		}
+
 		if (!_move_one_lv(vg_from, vg_to, lvh, &lvht))
 			return_0;
 	}