LVM2 ./WHATS_NEW lib/Makefile.in lib/activate/ ...

[jbrassow@sourceware.org <jbrassow@sourceware.org>]

CVSROOT:	/cvs/lvm2
Module name:	LVM2
Changes by:	jbrassow at sourceware.org	2011-08-11 18:24:42

Modified files:
	.              : WHATS_NEW 
	lib            : Makefile.in 
	lib/activate   : activate.c activate.h 
	lib/metadata   : metadata-exported.h 
	tools          : lvconvert.c 
Added files:
	lib/metadata   : raid_manip.c 
	test           : t-lvcreate-raid.sh 

Log message:
	Add ability to down-convert RAID1 arrays.
	
	Also, add some simple RAID tests to testsuite.

Patches:
http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/WHATS_NEW.diff?cvsroot=lvm2&r1=1.2068&r2=1.2069
http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/lib/Makefile.in.diff?cvsroot=lvm2&r1=1.110&r2=1.111
http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/lib/activate/activate.c.diff?cvsroot=lvm2&r1=1.210&r2=1.211
http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/lib/activate/activate.h.diff?cvsroot=lvm2&r1=1.78&r2=1.79
http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/lib/metadata/raid_manip.c.diff?cvsroot=lvm2&r1=NONE&r2=1.1
http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/lib/metadata/metadata-exported.h.diff?cvsroot=lvm2&r1=1.197&r2=1.198
http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/test/t-lvcreate-raid.sh.diff?cvsroot=lvm2&r1=NONE&r2=1.1
http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/tools/lvconvert.c.diff?cvsroot=lvm2&r1=1.167&r2=1.168

--- LVM2/WHATS_NEW	2011/08/11 17:55:29	1.2068
+++ LVM2/WHATS_NEW	2011/08/11 18:24:40	1.2069
@@ -1,5 +1,6 @@
 Version 2.02.87 - 
 ===============================
+  Add ability to down-convert RAID1 arrays.
   Update udev rules to skip DM flags decoding for removed devices.
   Add detect_internal_vg_cache_corruption to lvm.conf, disabled by default.
   Use memory pool locking to check for corruption of internal VG structs.
--- LVM2/lib/Makefile.in	2011/08/02 22:07:21	1.110
+++ LVM2/lib/Makefile.in	2011/08/11 18:24:41	1.111
@@ -85,6 +85,7 @@
 	metadata/pv.c \
 	metadata/pv_manip.c \
 	metadata/pv_map.c \
+	metadata/raid_manip.c \
 	metadata/replicator_manip.c \
 	metadata/segtype.c \
 	metadata/snapshot_manip.c \
--- LVM2/lib/activate/activate.c	2011/08/10 20:25:29	1.210
+++ LVM2/lib/activate/activate.c	2011/08/11 18:24:41	1.211
@@ -611,6 +611,11 @@
 	return r;
 }
 
+int lv_raid_percent(const struct logical_volume *lv, percent_t *percent)
+{
+	return lv_mirror_percent(lv->vg->cmd, lv, 0, percent, NULL);
+}
+
 static int _lv_active(struct cmd_context *cmd, struct logical_volume *lv)
 {
 	struct lvinfo info;
--- LVM2/lib/activate/activate.h	2011/06/22 21:31:21	1.78
+++ LVM2/lib/activate/activate.h	2011/08/11 18:24:41	1.79
@@ -93,6 +93,7 @@
 int lv_snapshot_percent(const struct logical_volume *lv, percent_t *percent);
 int lv_mirror_percent(struct cmd_context *cmd, const struct logical_volume *lv,
 		      int wait, percent_t *percent, uint32_t *event_nr);
+int lv_raid_percent(const struct logical_volume *lv, percent_t *percent);
 
 /*
  * Return number of LVs in the VG that are active.
/cvs/lvm2/LVM2/lib/metadata/raid_manip.c,v  -->  standard output
revision 1.1
--- LVM2/lib/metadata/raid_manip.c
+++ -	2011-08-11 18:24:43.628072000 +0000
@@ -0,0 +1,478 @@
+/*
+ * Copyright (C) 2011 Red Hat, Inc. All rights reserved.
+ *
+ * This file is part of LVM2.
+ *
+ * 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 Lesser General Public License v.2.1.
+ *
+ * You should have received a copy of the GNU Lesser 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
+ */
+
+#include "lib.h"
+#include "metadata.h"
+#include "toolcontext.h"
+#include "segtype.h"
+#include "display.h"
+#include "archiver.h"
+#include "activate.h"
+#include "lv_alloc.h"
+#include "lvm-string.h"
+#include "str_list.h"
+#include "memlock.h"
+
+uint32_t lv_raid_image_count(const struct logical_volume *lv)
+{
+	struct lv_segment *seg = first_seg(lv);
+
+	if (!seg_is_raid(seg))
+		return 1;
+
+	return seg->area_count;
+}
+
+/*
+ * lv_is_on_pv
+ * @lv:
+ * @pv:
+ *
+ * If any of the component devices of the LV are on the given PV, 1
+ * is returned; otherwise 0.  For example if one of the images of a RAID
+ * (or its metadata device) is on the PV, 1 would be returned for the
+ * top-level LV.
+ * If you wish to check the images themselves, you should pass them.
+ *
+ * FIXME:  This should be made more generic, possibly use 'for_each_sub_lv',
+ * and be put in lv_manip.c.  'for_each_sub_lv' does not yet allow us to
+ * short-circuit execution or pass back the values we need yet though...
+ */
+static int lv_is_on_pv(struct logical_volume *lv, struct physical_volume *pv)
+{
+	uint32_t s;
+	struct physical_volume *pv2;
+	struct lv_segment *seg;
+
+	if (!lv)
+		return 0;
+
+	seg = first_seg(lv);
+	if (!seg)
+		return 0;
+
+	/* Check mirror log */
+	if (lv_is_on_pv(seg->log_lv, pv))
+		return 1;
+
+	/* Check stack of LVs */
+	dm_list_iterate_items(seg, &lv->segments) {
+		for (s = 0; s < seg->area_count; s++) {
+			if (seg_type(seg, s) == AREA_PV) {
+				pv2 = seg_pv(seg, s);
+				if (id_equal(&pv->id, &pv2->id))
+					return 1;
+				if (pv->dev && pv2->dev &&
+				    (pv->dev->dev == pv2->dev->dev))
+					return 1;
+			}
+
+			if ((seg_type(seg, s) == AREA_LV) &&
+			    lv_is_on_pv(seg_lv(seg, s), pv))
+				return 1;
+
+			if (!seg_is_raid(seg))
+				continue;
+
+			/* This is RAID, so we know the meta_area is AREA_LV */
+			if (lv_is_on_pv(seg_metalv(seg, s), pv))
+				return 1;
+		}
+	}
+
+	return 0;
+}
+
+static int lv_is_on_pvs(struct logical_volume *lv, struct dm_list *pvs)
+{
+	struct pv_list *pvl;
+
+	dm_list_iterate_items(pvl, pvs)
+		if (lv_is_on_pv(lv, pvl->pv)) {
+			log_debug("%s is on %s", lv->name,
+				  pv_dev_name(pvl->pv));
+			return 1;
+		} else
+			log_debug("%s is not on %s", lv->name,
+				  pv_dev_name(pvl->pv));
+	return 0;
+}
+
+static int raid_in_sync(struct logical_volume *lv)
+{
+	percent_t sync_percent;
+
+	if (!lv_raid_percent(lv, &sync_percent)) {
+		log_error("Unable to determine sync status of %s/%s.",
+			  lv->vg->name, lv->name);
+		return 0;
+	}
+
+	return (sync_percent == PERCENT_100) ? 1 : 0;
+}
+
+/*
+ * _shift_and_rename_image_components
+ * @seg: Top-level RAID segment
+ *
+ * Shift all higher indexed segment areas down to fill in gaps where
+ * there are 'AREA_UNASSIGNED' areas and rename data/metadata LVs so
+ * that their names match their new index.  When finished, set
+ * seg->area_count to new reduced total.
+ *
+ * Returns: 1 on success, 0 on failure
+ */
+static int _shift_and_rename_image_components(struct lv_segment *seg)
+{
+	int len;
+	char *shift_name;
+	uint32_t s, missing;
+	struct cmd_context *cmd = seg->lv->vg->cmd;
+
+	/*
+	 * All LVs must be properly named for their index before
+	 * shifting begins.  (e.g.  Index '0' must contain *_rimage_0 and
+	 * *_rmeta_0.  Index 'n' must contain *_rimage_n and *_rmeta_n.)
+	 */
+
+	if (!seg_is_raid(seg))
+		return_0;
+
+	if (seg->area_count > 10) {
+		/*
+		 * FIXME: Handling more would mean I'd have
+		 * to handle double digits
+		 */
+		log_error("Unable handle arrays with more than 10 devices");
+		return 0;
+	}
+
+	log_very_verbose("Shifting images in %s", seg->lv->name);
+
+	for (s = 0, missing = 0; s < seg->area_count; s++) {
+		if (seg_type(seg, s) == AREA_UNASSIGNED) {
+			if (seg_metatype(seg, s) != AREA_UNASSIGNED) {
+				log_error(INTERNAL_ERROR "Metadata segment area"
+					  " #%d should be AREA_UNASSIGNED", s);
+				return 0;
+			}
+			missing++;
+			continue;
+		}
+		if (!missing)
+			continue;
+
+		log_very_verbose("Shifting %s and %s by %u",
+				 seg_metalv(seg, s)->name,
+				 seg_lv(seg, s)->name, missing);
+
+		/* Alter rmeta name */
+		shift_name = dm_pool_strdup(cmd->mem, seg_metalv(seg, s)->name);
+		if (!shift_name)
+			return_0;
+		len = strlen(shift_name) - 1;
+		shift_name[len] -= missing;
+		seg_metalv(seg, s)->name = shift_name;
+
+		/* Alter rimage name */
+		shift_name = dm_pool_strdup(cmd->mem, seg_lv(seg, s)->name);
+		if (!shift_name)
+			return_0;
+		len = strlen(shift_name) - 1;
+		shift_name[len] -= missing;
+		seg_lv(seg, s)->name = shift_name;
+
+		seg->areas[s - missing] = seg->areas[s];
+		seg->meta_areas[s - missing] = seg->meta_areas[s];
+	}
+
+	seg->area_count -= missing;
+	return 1;
+}
+
+static int raid_add_images(struct logical_volume *lv,
+			   uint32_t new_count, struct dm_list *pvs)
+{
+	/* Not implemented */
+	log_error("Unable to add images to LV, %s/%s",
+		  lv->vg->name, lv->name);
+
+	return 0;
+}
+
+/*
+ * _extract_image_components
+ * @seg
+ * @idx:  The index in the areas array to remove
+ * @extracted_rmeta:  The displaced metadata LV
+ * @extracted_rimage:  The displaced data LV
+ *
+ * This function extracts the image components - setting the respective
+ * 'extracted' pointers.  It appends '_extracted' to the LVs' names, so that
+ * there are not future conflicts.  It does /not/ commit the results.
+ * (IOW, erroring-out requires no unwinding of operations.)
+ *
+ * This function does /not/ attempt to:
+ *    1) shift the 'areas' or 'meta_areas' arrays.
+ *       The '[meta_]areas' are left as AREA_UNASSIGNED.
+ *    2) Adjust the seg->area_count
+ *    3) Name the extracted LVs appropriately (appends '_extracted' to names)
+ * These actions must be performed by the caller.
+ *
+ * Returns: 1 on success, 0 on failure
+ */
+static int _extract_image_components(struct lv_segment *seg, uint32_t idx,
+				     struct logical_volume **extracted_rmeta,
+				     struct logical_volume **extracted_rimage)
+{
+	int len;
+	char *tmp_name;
+	struct cmd_context *cmd = seg->lv->vg->cmd;
+	struct logical_volume *data_lv = seg_lv(seg, idx);
+	struct logical_volume *meta_lv = seg_metalv(seg, idx);
+
+	log_very_verbose("Extracting image components %s and %s from %s",
+			 data_lv->name, meta_lv->name, seg->lv->name);
+
+	data_lv->status &= ~RAID_IMAGE;
+	meta_lv->status &= ~RAID_META;
+	lv_set_visible(data_lv);
+	lv_set_visible(meta_lv);
+
+	/* release removes data and meta areas */
+	remove_seg_from_segs_using_this_lv(data_lv, seg);
+	remove_seg_from_segs_using_this_lv(meta_lv, seg);
+
+	seg_type(seg, idx) = AREA_UNASSIGNED;
+	seg_metatype(seg, idx) = AREA_UNASSIGNED;
+
+	len = strlen(meta_lv->name) + strlen("_extracted") + 1;
+	tmp_name = dm_pool_alloc(cmd->mem, len);
+	if (!tmp_name)
+		return_0;
+	sprintf(tmp_name, "%s_extracted", meta_lv->name);
+	meta_lv->name = tmp_name;
+
+	len = strlen(data_lv->name) + strlen("_extracted") + 1;
+	tmp_name = dm_pool_alloc(cmd->mem, len);
+	if (!tmp_name)
+		return_0;
+	sprintf(tmp_name, "%s_extracted", data_lv->name);
+	data_lv->name = tmp_name;
+
+	*extracted_rmeta = meta_lv;
+	*extracted_rimage = data_lv;
+
+	return 1;
+}
+
+/*
+ * raid_extract_images
+ * @lv
+ * @new_count:  The absolute count of images (e.g. '2' for a 2-way mirror)
+ * @target_pvs:  The list of PVs that are candidates for removal
+ * @shift:  If set, use _shift_and_rename_image_components().
+ *          Otherwise, leave the [meta_]areas as AREA_UNASSIGNED and
+ *          seg->area_count unchanged.
+ * @extracted_[meta|data]_lvs:  The LVs removed from the array.  If 'shift'
+ *                              is set, then there will likely be name conflicts.
+ *
+ * This function extracts _both_ portions of the indexed image.  It
+ * does /not/ commit the results.  (IOW, erroring-out requires no unwinding
+ * of operations.)
+ *
+ * Returns: 1 on success, 0 on failure
+ */
+static int raid_extract_images(struct logical_volume *lv, uint32_t new_count,
+			       struct dm_list *target_pvs, int shift,
+			       struct dm_list *extracted_meta_lvs,
+			       struct dm_list *extracted_data_lvs)
+{
+	int s, extract, lvl_idx = 0;
+	struct lv_list *lvl_array;
+	struct lv_segment *seg = first_seg(lv);
+	struct logical_volume *rmeta_lv, *rimage_lv;
+
+	extract = seg->area_count - new_count;
+	log_verbose("Extracting %u %s from %s/%s", extract,
+		    (extract > 1) ? "images" : "image",
+		    lv->vg->name, lv->name);
+
+	lvl_array = dm_pool_alloc(lv->vg->cmd->mem,
+				  sizeof(*lvl_array) * extract * 2);
+	if (!lvl_array)
+		return_0;
+
+	for (s = seg->area_count - 1; (s >= 0) && extract; s--) {
+		if (!lv_is_on_pvs(seg_lv(seg, s), target_pvs) ||
+		    !lv_is_on_pvs(seg_metalv(seg, s), target_pvs))
+			continue;
+		if (!raid_in_sync(lv) &&
+		    (!seg_is_mirrored(seg) || (s == 0))) {
+			log_error("Unable to extract %sRAID image"
+				  " while RAID array is not in-sync",
+				  seg_is_mirrored(seg) ? "primary " : "");
+			return 0;
+		}
+
+		if (!_extract_image_components(seg, s, &rmeta_lv, &rimage_lv)) {
+			log_error("Failed to extract %s from %s",
+				  seg_lv(seg, s)->name, lv->name);
+			return 0;
+		}
+
+		if (shift && !_shift_and_rename_image_components(seg)) {
+			log_error("Failed to shift and rename image components");
+			return 0;
+		}
+
+		lvl_array[lvl_idx].lv = rmeta_lv;
+		lvl_array[lvl_idx + 1].lv = rimage_lv;
+		dm_list_add(extracted_meta_lvs, &(lvl_array[lvl_idx++].list));
+		dm_list_add(extracted_data_lvs, &(lvl_array[lvl_idx++].list));
+
+		extract--;
+	}
+	if (extract) {
+		log_error("Unable to extract enough images to satisfy request");
+		return 0;
+	}
+
+	return 1;
+}
+
+/*
+ * lv_raid_change_image_count
+ * @lv
+ * @new_count: The absolute count of images (e.g. '2' for a 2-way mirror)
+ * @pvs: The list of PVs that are candidates for removal (or empty list)
+ *
+ * RAID arrays have 'images' which are composed of two parts, they are:
+ *    - 'rimage': The data/parity holding portion
+ *    - 'rmeta' : The metadata holding portion (i.e. superblock/bitmap area)
+ * This function adds or removes _both_ portions of the image and commits
+ * the results.
+ *
+ * Returns: 1 on success, 0 on failure
+ */
+int lv_raid_change_image_count(struct logical_volume *lv,
+			       uint32_t new_count, struct dm_list *pvs)
+{
+	int r;
+	uint32_t old_count = lv_raid_image_count(lv);
+	struct lv_segment *seg = first_seg(lv);
+	struct dm_list removal_list;
+	struct lv_list *lvl_array, *lvl;
+
+	dm_list_init(&removal_list);
+
+	if (!seg_is_mirrored(seg)) {
+		log_error("Unable to change image count of non-mirrored RAID.");
+		return 0;
+	}
+
+	if (old_count == new_count) {
+		log_verbose("%s/%s already has image count of %d",
+			    lv->vg->name, lv->name, new_count);
+		return 1;
+	}
+
+	if (old_count > new_count)
+		r = raid_extract_images(lv, new_count, pvs, 1,
+					&removal_list, &removal_list);
+	else
+		r = raid_add_images(lv, new_count, pvs);
+	if (!r)
+		return 0;
+
+	/* Convert to linear? */
+	if (new_count == 1) {
+		/* Add last metadata area to removal_list */
+		lvl_array = dm_pool_alloc(lv->vg->cmd->mem, 2 * sizeof(*lvl));
+		if (!lvl_array)
+			return_0;
+		lvl_array[0].lv = seg_metalv(seg, 0);
+		remove_seg_from_segs_using_this_lv(seg_metalv(seg, 0), seg);
+		seg_metatype(seg, 0) = AREA_UNASSIGNED;
+		dm_list_add(&removal_list, &(lvl_array[0].list));
+
+		/* Remove RAID layer */
+		seg_lv(seg, 0)->status &= ~RAID_IMAGE;
+		lv_set_visible(seg_lv(seg, 0));
+		lvl_array[1].lv = seg_lv(seg, 0);
+		dm_list_add(&removal_list, &(lvl_array[1].list));
+
+		if (!remove_layer_from_lv(lv, seg_lv(seg, 0)))
+			return_0;
+		lv->status &= ~(MIRRORED | RAID);
+	}
+
+	if (!vg_write(lv->vg)) {
+		log_error("Failed to write changes to %s in %s",
+			  lv->name, lv->vg->name);
+		return 0;
+	}
+
+	if (!suspend_lv(lv->vg->cmd, lv)) {
+		log_error("Failed to suspend %s/%s before committing changes",
+			  lv->vg->name, lv->name);
+		return 0;
+	}
+
+	if (!vg_commit(lv->vg)) {
+		log_error("Failed to commit changes to %s in %s",
+			  lv->name, lv->vg->name);
+		return 0;
+	}
+
+	/*
+	 * Bring extracted LVs into existance, so there are no
+	 * conflicts for the main RAID device's resume
+	 */
+	if (!dm_list_empty(&removal_list)) {
+		dm_list_iterate_items(lvl, &removal_list) {
+			/* If top RAID was EX, use EX */
+			if (lv_is_active_exclusive_locally(lv)) {
+				if (!activate_lv_excl(lv->vg->cmd, lvl->lv))
+					return_0;
+			} else {
+				if (!activate_lv(lv->vg->cmd, lvl->lv))
+					return_0;
+			}
+		}
+	}
+
+	if (!resume_lv(lv->vg->cmd, lv)) {
+		log_error("Failed to resume %s/%s after committing changes",
+			  lv->vg->name, lv->name);
+		return 0;
+	}
+
+	/*
+	 * Eliminate the extracted LVs
+	 */
+	if (!dm_list_empty(&removal_list)) {
+		dm_list_iterate_items(lvl, &removal_list) {
+			if (!deactivate_lv(lv->vg->cmd, lvl->lv))
+				return_0;
+			if (!lv_remove(lvl->lv))
+				return_0;
+		}
+
+		if (!vg_write(lv->vg) || !vg_commit(lv->vg))
+			return_0;
+	}
+
+	return 1;
+}
--- LVM2/lib/metadata/metadata-exported.h	2011/08/11 03:29:52	1.197
+++ LVM2/lib/metadata/metadata-exported.h	2011/08/11 18:24:41	1.198
@@ -737,6 +737,13 @@
 int lv_is_slog(const struct logical_volume *lv);
 struct logical_volume *first_replicator_dev(const struct logical_volume *lv);
 /* --  metadata/replicator_manip.c */
+
+/* ++  metadata/raid_manip.c */
+uint32_t lv_raid_image_count(const struct logical_volume *lv);
+int lv_raid_change_image_count(struct logical_volume *lv,
+			       uint32_t new_count, struct dm_list *pvs);
+/* --  metadata/raid_manip.c */
+
 struct cmd_vg *cmd_vg_add(struct dm_pool *mem, struct dm_list *cmd_vgs,
 			  const char *vg_name, const char *vgid,
 			  uint32_t flags);
/cvs/lvm2/LVM2/test/t-lvcreate-raid.sh,v  -->  standard output
revision 1.1
--- LVM2/test/t-lvcreate-raid.sh
+++ -	2011-08-11 18:24:43.896171000 +0000
@@ -0,0 +1,122 @@
+# Copyright (C) 2011 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
+
+. lib/test
+
+# is_raid_in_sync <VG/LV>
+function is_raid_in_sync()
+{
+	local dm_name
+	local a
+	local b
+	local idx
+
+	dm_name=`echo $1 | sed s:-:--: | sed s:/:-:`
+
+	if ! a=(`dmsetup status $dm_name`); then
+		echo "Unable to get sync status of $1"
+		exit 1
+	fi
+	idx=$((${#a[@]} - 1))
+	b=(`echo ${a[$idx]} | sed s:/:' ':`)
+
+	if [ ${b[0]} != ${b[1]} ]; then
+		echo "$dm_name (${a[3]}) is not in-sync"
+		return 1
+	fi
+
+	echo "$dm_name (${a[3]}) is in-sync"
+	return 0
+}
+
+# wait_for_raid_sync <VG/LV>
+function wait_for_raid_sync()
+{
+	local i=0
+
+	while ! is_raid_in_sync $1; do
+		sleep 2
+		i=$(($i + 1))
+		if [ $i -gt 500 ]; then
+			echo "Sync is taking too long - assume stuck"
+			exit 1
+		fi
+	done
+}
+
+function is_raid_available()
+{
+	local a
+
+	modprobe dm-raid
+	a=(`dmsetup targets | grep raid`)
+	if [ -z $a ]; then
+		echo "RAID target not available"
+		return 1
+	fi
+	if [ ${a[1]} != "v1.1.0" ]; then
+		echo "Bad RAID version"
+		return 1
+	fi
+
+	return 0
+}
+
+########################################################
+# MAIN
+########################################################
+is_raid_available || exit 200
+
+aux prepare_vg 5 80
+
+
+###########################################
+# Create, wait for sync, remove tests
+###########################################
+
+# Create RAID1 (implicit 2-way)
+lvcreate --type raid1 -l 2 -n $lv1 $vg
+wait_for_raid_sync $vg/$lv1
+lvremove -ff $vg
+
+# Create RAID1 (explicit 2-way)
+lvcreate --type raid1 -m 1 -l 2 -n $lv1 $vg
+wait_for_raid_sync $vg/$lv1
+lvremove -ff $vg
+
+# Create RAID1 (explicit 3-way)
+lvcreate --type raid1 -m 2 -l 2 -n $lv1 $vg
+wait_for_raid_sync $vg/$lv1
+lvremove -ff $vg
+
+# Create RAID 4/5/6 (explicit 3-stripe + parity devs)
+for i in raid4 \
+	raid5 raid5_ls raid5_la raid5_rs raid5_ra \
+	raid6 raid6_zr raid6_nr raid6_nc; do
+
+	lvcreate --type $i -l 3 -i 3 -n $lv1 $vg
+	wait_for_raid_sync $vg/$lv1
+	lvremove -ff $vg
+done
+
+###########################################
+# RAID1 down-convert tests
+###########################################
+
+# 3-way to 2-way
+lvcreate --type raid1 -m 2 -l 2 -n $lv1 $vg
+wait_for_raid_sync $vg/$lv1
+lvconvert -m 1 $vg/$lv1
+# FIXME: ensure no residual devices
+
+# 2-way to linear
+lvconvert -m 0 $vg/$lv1
+# FIXME: ensure no residual devices
+lvremove -ff $vg
--- LVM2/tools/lvconvert.c	2011/08/10 20:25:31	1.167
+++ LVM2/tools/lvconvert.c	2011/08/11 18:24:42	1.168
@@ -39,7 +39,7 @@
 	uint32_t stripes;
 	uint32_t stripe_size;
 
-	struct segment_type *segtype;
+	const struct segment_type *segtype;
 
 	alloc_policy_t alloc;
 
@@ -1366,6 +1366,62 @@
 	return 1;
 }
 
+static int is_valid_raid_conversion(const struct segment_type *from_segtype,
+				    const struct segment_type *to_segtype)
+{
+	if (from_segtype == to_segtype)
+		return 1;
+
+	if (!segtype_is_raid(from_segtype) && !segtype_is_raid(to_segtype))
+		return_0;  /* Not converting to or from RAID? */
+
+	return 0;
+}
+
+static int lvconvert_raid(struct logical_volume *lv, struct lvconvert_params *lp)
+{
+	int image_count;
+	struct cmd_context *cmd = lv->vg->cmd;
+	struct lv_segment *seg = first_seg(lv);
+
+	if (!arg_count(cmd, type_ARG))
+		lp->segtype = seg->segtype;
+
+	if (arg_count(cmd, mirrors_ARG) && !seg_is_mirrored(seg)) {
+		log_error("'--mirrors/-m' is not compatible with %s",
+			  seg->segtype->name);
+		return 0;
+	}
+
+	if (!is_valid_raid_conversion(seg->segtype, lp->segtype)) {
+		log_error("Unable to convert %s/%s from %s to %s",
+			  lv->vg->name, lv->name,
+			  seg->segtype->name, lp->segtype->name);
+		return 0;
+	}
+
+	/* Change number of RAID1 images */
+	if (arg_count(cmd, mirrors_ARG)) {
+		image_count = lv_raid_image_count(lv);
+		if (lp->mirrors_sign == SIGN_PLUS)
+			image_count += lp->mirrors;
+		else if (lp->mirrors_sign == SIGN_MINUS)
+			image_count -= lp->mirrors;
+		else
+			image_count = lp->mirrors + 1;
+
+		if (image_count < 1) {
+			log_error("Unable to reduce images by specified amount");
+			return 0;
+		}
+
+		return lv_raid_change_image_count(lv, image_count, lp->pvh);
+	}
+
+	log_error("Conversion operation not yet supported.");
+	return 0;
+}
+
 static int lvconvert_snapshot(struct cmd_context *cmd,
 			      struct logical_volume *lv,
 			      struct lvconvert_params *lp)
@@ -1580,6 +1636,24 @@
 			stack;
 			return ECMD_FAILED;
 		}
+	} else if (segtype_is_raid(lp->segtype) || (lv->status & RAID)) {
+		if (!archive(lv->vg)) {
+			stack;
+			return ECMD_FAILED;
+		}
+		if (!lvconvert_raid(lv, lp)) {
+			stack;
+			return ECMD_FAILED;
+		}
+
+		if (!(failed_pvs = _failed_pv_list(lv->vg))) {
+			stack;
+			return ECMD_FAILED;
+		}
+
+		/* If repairing and using policies, remove missing PVs from VG */
+		if (arg_count(cmd, repair_ARG) && arg_count(cmd, use_policies_ARG))
+			_remove_missing_empty_pv(lv->vg, failed_pvs);
 	} else if (arg_count(cmd, mirrors_ARG) ||
 		   arg_count(cmd, splitmirrors_ARG) ||
 		   (lv->status & MIRRORED)) {