thin: vgsplit support for thins

Support vgsplit for VGs with thin pools and thin volumes.
In case the thin data and thin metadata volumes are moved to a new VG,
move there also all related thin volumes and check that external origins
are also present in this new VG.

WHATS_NEW

@@ -1,5 +1,6 @@
 Version 2.02.99 - 
 ===================================
+  Add support for thin volumes in vgsplit.
   Also filter partitions on mpath components if multipath_component_detection=1.
   Add lvresize support for online thin pool metadata volume resize.
   Add helper functions find_pool_lv() and pool_can_resize_metadata().

test/shell/vgsplit-thin.sh

@@ -0,0 +1,39 @@
+#!/bin/sh
+# Copyright (C) 2013 Red Hat, Inc. All rights reserved.
+#
+# This copyrighted material is made available to anyone wishing to use,
+# modify, copy, or redistribute it subject to the terms and conditions
+# of the GNU General Public License v.2.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software Foundation,
+# Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+# Test vgsplit command options for validity
+
+. lib/test
+
+aux have_thin 1 0 0 || skip
+
+aux prepare_devs 5
+
+vgcreate $vg1 $(cat DEVICES)
+lvcreate -T -L8M $vg1/pool1 -V10M -n $lv1 "$dev1" "$dev2"
+lvcreate -T -L8M $vg1/pool2 -V10M -n $lv2 "$dev3" "$dev4"
+
+# Test with external origin if available
+lvcreate -l1 -an -pr --zero n -n eorigin $vg1 "$dev5"
+aux have_thin 1 5 0 && lvcreate -an -s $vg1/eorigin -n $lv3 --thinpool $vg1/pool1
+
+# Cannot move active thin
+not vgsplit $vg1 $vg2 "$dev1" "$dev2" "$dev5"
+
+vgchange -an $vg1
+not vgsplit $vg1 $vg2 "$dev1"
+not vgsplit $vg1 $vg2 "$dev2" "$dev3"
+vgsplit $vg1 $vg2 "$dev1" "$dev2" "$dev5"
+lvs -a -o+devices $vg1 $vg2
+
+vgmerge $vg1 $vg2
+
+vgremove -ff $vg1

tools/vgsplit.c

@@ -62,6 +62,10 @@ static int _move_lvs(struct volume_group *vg_from, struct volume_group *vg_to)
 		if ((lv->status & MIRRORED))
 			continue;
 
+		if (lv_is_thin_pool(lv) ||
+		    lv_is_thin_volume(lv))
+			continue;
+
 		/* Ensure all the PVs used by this LV remain in the same */
 		/* VG as each other */
 		vg_with = NULL;
@@ -211,6 +215,53 @@ static int _move_mirrors(struct volume_group *vg_from,
 	return 1;
 }
 
+static int _move_thins(struct volume_group *vg_from,
+		       struct volume_group *vg_to)
+{
+	struct dm_list *lvh, *lvht;
+	struct logical_volume *lv, *data_lv;
+	struct lv_segment *seg;
+
+	dm_list_iterate_safe(lvh, lvht, &vg_from->lvs) {
+		lv = dm_list_item(lvh, struct lv_list)->lv;
+
+		if (lv_is_thin_volume(lv)) {
+			seg = first_seg(lv);
+			data_lv = seg_lv(first_seg(seg->pool_lv), 0);
+			if ((_lv_is_in_vg(vg_to, data_lv) ||
+			     _lv_is_in_vg(vg_to, seg->external_lv))) {
+				if (_lv_is_in_vg(vg_from, seg->external_lv) ||
+				    _lv_is_in_vg(vg_from, data_lv)) {
+					log_error("Can't split external origin %s "
+						  "and pool %s between two Volume Groups.",
+						  seg->external_lv->name,
+						  seg->pool_lv->name);
+					return 0;
+				}
+				if (!_move_one_lv(vg_from, vg_to, lvh))
+					return_0;
+			}
+		} else if (lv_is_thin_pool(lv)) {
+			seg = first_seg(lv);
+			data_lv = seg_lv(seg, 0);
+			if (_lv_is_in_vg(vg_to, data_lv) ||
+			    _lv_is_in_vg(vg_to, seg->metadata_lv)) {
+				if (_lv_is_in_vg(vg_from, seg->metadata_lv) ||
+				    _lv_is_in_vg(vg_from, data_lv)) {
+					log_error("Can't split pool data and metadata %s "
+						  "between two Volume Groups.",
+						  lv->name);
+					return 0;
+				}
+				if (!_move_one_lv(vg_from, vg_to, lvh))
+					return_0;
+			}
+		}
+	}
+
+	return 1;
+}
+
 /*
  * Create or open the destination of the vgsplit operation.
  * Returns
@@ -430,6 +481,10 @@ int vgsplit(struct cmd_context *cmd, int argc, char **argv)
 	if (!(_move_snapshots(vg_from, vg_to)))
 		goto_bad;
 
+	/* Move required pools across */
+	if (!(_move_thins(vg_from, vg_to)))
+		goto_bad;
+
 	/* Split metadata areas and check if both vgs have at least one area */
 	if (!(vg_split_mdas(cmd, vg_from, vg_to)) && vg_from->pv_count) {
 		log_error("Cannot split: Nowhere to store metadata for new Volume Group");