Support the ability to replace specific devices in a RAID array.

RAID is not like traditional LVM mirroring.  LVM mirroring required failed
devices to be removed or the logical volume would simply hang.  RAID arrays can
keep on running with failed devices.  In fact, for RAID types other than RAID1,
removing a device would mean substituting an error target or converting to a
lower level RAID (e.g. RAID6 -> RAID5, or RAID4/5 to RAID0).  Therefore, rather
than removing a failed device unconditionally and potentially allocating a
replacement, RAID allows the user to "replace" a device with a new one.  This
approach is a 1-step solution vs the current 2-step solution.

example> lvconvert --replace <dev_to_remove> vg/lv [possible_replacement_PVs]

'--replace' can be specified more than once.

example> lvconvert --replace /dev/sdb1 --replace /dev/sdc1 vg/lv

10 files changed, 317 insertions, 11 deletions

diff --git a/WHATS_NEW b/WHATS_NEW
index 0e8a5560..4caa10ca 100644
--- a/WHATS_NEW
+++ b/WHATS_NEW
@@ -1,5 +1,6 @@
 Version 2.02.89 - 
 ==================================
+  Support the ability to replace specific devices in a RAID array via lvconvert.
   Add activation/use_linear_target enabled by default.
   Use gcc warning options only with .c to .o compilation.
   Move y/n prompts to stderr and repeat if response has both 'n' and 'y'.
diff --git a/lib/format_text/flags.c b/lib/format_text/flags.c
index 9b2788f4..dbca8c98 100644
--- a/lib/format_text/flags.c
+++ b/lib/format_text/flags.c
@@ -57,6 +57,7 @@ static const struct flag _lv_flags[] = {
 	{PVMOVE, "PVMOVE", STATUS_FLAG},
 	{LOCKED, "LOCKED", STATUS_FLAG},
 	{LV_NOTSYNCED, "NOTSYNCED", STATUS_FLAG},
+	{LV_REBUILD, "REBUILD", STATUS_FLAG},
 	{RAID, NULL, 0},
 	{RAID_META, NULL, 0},
 	{RAID_IMAGE, NULL, 0},
diff --git a/lib/metadata/metadata-exported.h b/lib/metadata/metadata-exported.h
index fff76318..2741a13b 100644
--- a/lib/metadata/metadata-exported.h
+++ b/lib/metadata/metadata-exported.h
@@ -61,7 +61,9 @@
 //#define VIRTUAL		UINT64_C(0x00010000)	/* LV - internal use only */
 #define MIRROR_LOG		UINT64_C(0x00020000)	/* LV */
 #define MIRROR_IMAGE		UINT64_C(0x00040000)	/* LV */
+
 #define LV_NOTSYNCED		UINT64_C(0x00080000)	/* LV */
+#define LV_REBUILD		UINT64_C(0x00100000)	/* LV - internal use only */
 //#define PRECOMMITTED		UINT64_C(0x00200000)	/* VG - internal use only */
 #define CONVERTING		UINT64_C(0x00400000)	/* LV */
 
@@ -788,6 +790,8 @@ int lv_raid_split_and_track(struct logical_volume *lv,
 int lv_raid_merge(struct logical_volume *lv);
 int lv_raid_reshape(struct logical_volume *lv,
 		    const struct segment_type *new_segtype);
+int lv_raid_replace(struct logical_volume *lv, struct dm_list *remove_pvs,
+		    struct dm_list *allocate_pvs);
 
 /* --  metadata/raid_manip.c */
 
diff --git a/lib/metadata/raid_manip.c b/lib/metadata/raid_manip.c
index a1a060ee..864faf19 100644
--- a/lib/metadata/raid_manip.c
+++ b/lib/metadata/raid_manip.c
@@ -440,7 +440,7 @@ static int _alloc_image_component(struct logical_volume *lv,
 		return 0;
 	}
 
-	status = LVM_READ | LVM_WRITE | LV_NOTSYNCED | type;
+	status = LVM_READ | LVM_WRITE | LV_REBUILD | type;
 	tmp_lv = lv_create_empty(img_name, NULL, status, ALLOC_INHERIT, lv->vg);
 	if (!tmp_lv) {
 		log_error("Failed to allocate new raid component, %s", img_name);
@@ -569,6 +569,7 @@ static int _alloc_rmeta_for_lv(struct logical_volume *data_lv,
 static int _raid_add_images(struct logical_volume *lv,
 			    uint32_t new_count, struct dm_list *pvs)
 {
+	int rebuild_flag_cleared = 0;
 	uint32_t s;
 	uint32_t old_count = lv_raid_image_count(lv);
 	uint32_t count = new_count - old_count;
@@ -588,7 +589,7 @@ static int _raid_add_images(struct logical_volume *lv,
 	 */
 	if (seg_is_linear(seg)) {
 		/* A complete resync will be done, no need to mark each sub-lv */
-		status_mask = ~(LV_NOTSYNCED);
+		status_mask = ~(LV_REBUILD);
 
 		if (!(lvl = dm_pool_alloc(lv->vg->vgmem, sizeof(*lvl)))) {
 			log_error("Memory allocation failed");
@@ -751,6 +752,27 @@ to be left for these sub-lvs.
 		return 0;
 	}
 
+	/*
+	 * Now that the 'REBUILD' has made its way to the kernel, we must
+	 * remove the flag so that the individual devices are not rebuilt
+	 * upon every activation.
+	 */
+	seg = first_seg(lv);
+	for (s = 0; s < seg->area_count; s++) {
+		if ((seg_lv(seg, s)->status & LV_REBUILD) ||
+		    (seg_metalv(seg, s)->status & LV_REBUILD)) {
+			seg_metalv(seg, s)->status &= ~LV_REBUILD;
+			seg_lv(seg, s)->status &= ~LV_REBUILD;
+			rebuild_flag_cleared = 1;
+		}
+	}
+	if (rebuild_flag_cleared &&
+	    (!vg_write(lv->vg) || !vg_commit(lv->vg))) {
+		log_error("Failed to clear REBUILD flag for %s/%s components",
+			  lv->vg->name, lv->name);
+		return 0;
+	}
+
 	return 1;
 
 fail:
@@ -1335,8 +1357,8 @@ static int _convert_mirror_to_raid1(struct logical_volume *lv,
 		log_debug("Adding %s to %s", lvl->lv->name, lv->name);
 
 		/* Images are known to be in-sync */
-		lvl->lv->status &= ~LV_NOTSYNCED;
-		first_seg(lvl->lv)->status &= ~LV_NOTSYNCED;
+		lvl->lv->status &= ~LV_REBUILD;
+		first_seg(lvl->lv)->status &= ~LV_REBUILD;
 		lv_set_hidden(lvl->lv);
 
 		if (!set_lv_segment_area_lv(seg, s, lvl->lv, 0,
@@ -1428,3 +1450,216 @@ int lv_raid_reshape(struct logical_volume *lv,
 		  seg->segtype->name, new_segtype->name);
 	return 0;
 }
+
+/*
+ * lv_raid_replace
+ * @lv
+ * @replace_pvs
+ * @allocatable_pvs
+ *
+ * Replace the specified PVs.
+ */
+int lv_raid_replace(struct logical_volume *lv,
+		    struct dm_list *remove_pvs,
+		    struct dm_list *allocate_pvs)
+{
+	uint32_t s, sd, match_count = 0;
+	struct dm_list old_meta_lvs, old_data_lvs;
+	struct dm_list new_meta_lvs, new_data_lvs;
+	struct lv_segment *raid_seg = first_seg(lv);
+	struct lv_list *lvl;
+	char *tmp_names[raid_seg->area_count * 2];
+
+	dm_list_init(&old_meta_lvs);
+	dm_list_init(&old_data_lvs);
+	dm_list_init(&new_meta_lvs);
+	dm_list_init(&new_data_lvs);
+
+	/*
+	 * How many sub-LVs are being removed?
+	 */
+	for (s = 0; s < raid_seg->area_count; s++) {
+		if ((seg_type(raid_seg, s) == AREA_UNASSIGNED) ||
+		    (seg_metatype(raid_seg, s) == AREA_UNASSIGNED)) {
+			log_error("Unable to replace RAID images while the "
+				  "array has unassigned areas");
+			return 0;
+		}
+
+		if (_lv_is_on_pvs(seg_lv(raid_seg, s), remove_pvs) ||
+		    _lv_is_on_pvs(seg_metalv(raid_seg, s), remove_pvs))
+			match_count++;
+	}
+
+	if (!match_count) {
+		log_verbose("%s/%s does not contain devices specified"
+			    " for replacement", lv->vg->name, lv->name);
+		return 1;
+	} else if (match_count == raid_seg->area_count) {
+		log_error("Unable to remove all PVs from %s/%s at once.",
+			  lv->vg->name, lv->name);
+		return 0;
+	} else if (raid_seg->segtype->parity_devs &&
+		   (match_count > raid_seg->segtype->parity_devs)) {
+		log_error("Unable to replace more than %u PVs from (%s) %s/%s",
+			  raid_seg->segtype->parity_devs,
+			  raid_seg->segtype->name, lv->vg->name, lv->name);
+		return 0;
+	}
+
+	/*
+	 * Allocate the new image components first
+	 * - This makes it easy to avoid all currently used devs
+	 * - We can immediately tell if there is enough space
+	 *
+	 * - We need to change the LV names when we insert them.
+	 */
+	if (!_alloc_image_components(lv, allocate_pvs, match_count,
+				     &new_meta_lvs, &new_data_lvs)) {
+		log_error("Failed to allocate replacement images for %s/%s",
+			  lv->vg->name, lv->name);
+		return 0;
+	}
+
+	/*
+	 * Remove the old images
+	 * - If we did this before the allocate, we wouldn't have to rename
+	 *   the allocated images, but it'd be much harder to avoid the right
+	 *   PVs during allocation.
+	 */
+	if (!_raid_extract_images(lv, raid_seg->area_count - match_count,
+				  remove_pvs, 0,
+				  &old_meta_lvs, &old_data_lvs)) {
+		log_error("Failed to remove the specified images from %s/%s",
+			  lv->vg->name, lv->name);
+		return 0;
+	}
+
+	/*
+	 * Skip metadata operation normally done to clear the metadata sub-LVs.
+	 *
+	 * The LV_REBUILD flag is set on the new sub-LVs,
+	 * so they will be rebuilt and we don't need to clear the metadata dev.
+	 */
+
+	for (s = 0; s < raid_seg->area_count; s++) {
+		tmp_names[s] = NULL;
+		sd = s + raid_seg->area_count;
+		tmp_names[sd] = NULL;
+
+		if ((seg_type(raid_seg, s) == AREA_UNASSIGNED) &&
+		    (seg_metatype(raid_seg, s) == AREA_UNASSIGNED)) {
+			/* Adjust the new metadata LV name */
+			lvl = dm_list_item(dm_list_first(&new_meta_lvs),
+					   struct lv_list);
+			dm_list_del(&lvl->list);
+			tmp_names[s] = dm_pool_alloc(lv->vg->vgmem,
+						    strlen(lvl->lv->name) + 1);
+			if (!tmp_names[s])
+				return_0;
+			if (dm_snprintf(tmp_names[s], strlen(lvl->lv->name) + 1,
+					"%s_rmeta_%u", lv->name, s) < 0)
+				return_0;
+			if (!set_lv_segment_area_lv(raid_seg, s, lvl->lv, 0,
+						    lvl->lv->status)) {
+				log_error("Failed to add %s to %s",
+					  lvl->lv->name, lv->name);
+				return 0;
+			}
+			lv_set_hidden(lvl->lv);
+
+			/* Adjust the new data LV name */
+			lvl = dm_list_item(dm_list_first(&new_data_lvs),
+					   struct lv_list);
+			dm_list_del(&lvl->list);
+			tmp_names[sd] = dm_pool_alloc(lv->vg->vgmem,
+						     strlen(lvl->lv->name) + 1);
+			if (!tmp_names[sd])
+				return_0;
+			if (dm_snprintf(tmp_names[sd], strlen(lvl->lv->name) + 1,
+					"%s_rimage_%u", lv->name, s) < 0)
+				return_0;
+			if (!set_lv_segment_area_lv(raid_seg, s, lvl->lv, 0,
+						    lvl->lv->status)) {
+				log_error("Failed to add %s to %s",
+					  lvl->lv->name, lv->name);
+				return 0;
+			}
+			lv_set_hidden(lvl->lv);
+		}
+	}
+
+	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;
+	}
+
+	if (!resume_lv(lv->vg->cmd, lv)) {
+		log_error("Failed to resume %s/%s after committing changes",
+			  lv->vg->name, lv->name);
+		return 0;
+	}
+
+	dm_list_iterate_items(lvl, &old_meta_lvs) {
+		if (!deactivate_lv(lv->vg->cmd, lvl->lv))
+			return_0;
+		if (!lv_remove(lvl->lv))
+			return_0;
+	}
+	dm_list_iterate_items(lvl, &old_data_lvs) {
+		if (!deactivate_lv(lv->vg->cmd, lvl->lv))
+			return_0;
+		if (!lv_remove(lvl->lv))
+			return_0;
+	}
+
+	/* Update new sub-LVs to correct name and clear REBUILD flag */
+	for (s = 0; s < raid_seg->area_count; s++) {
+		sd = s + raid_seg->area_count;
+		if (tmp_names[s] && tmp_names[sd]) {
+			seg_metalv(raid_seg, s)->name = tmp_names[s];
+			seg_lv(raid_seg, s)->name = tmp_names[sd];
+			seg_metalv(raid_seg, s)->status &= ~LV_REBUILD;
+			seg_lv(raid_seg, s)->status &= ~LV_REBUILD;
+		}
+	}
+
+	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;
+	}
+
+	if (!resume_lv(lv->vg->cmd, lv)) {
+		log_error("Failed to resume %s/%s after committing changes",
+			  lv->vg->name, lv->name);
+		return 0;
+	}
+
+	return 1;
+}
diff --git a/lib/raid/raid.c b/lib/raid/raid.c
index c3fc4b13..445146b0 100644
--- a/lib/raid/raid.c
+++ b/lib/raid/raid.c
@@ -183,7 +183,7 @@ static int _raid_add_target_line(struct dev_manager *dm __attribute__((unused)),
 	}
 
 	for (s = 0; s < seg->area_count; s++)
-		if (seg_lv(seg, s)->status & LV_NOTSYNCED)
+		if (seg_lv(seg, s)->status & LV_REBUILD)
 			rebuilds |= 1 << s;
 
 	if (!dm_tree_node_add_raid_target(node, len, _raid_name(seg),
diff --git a/libdm/ioctl/libdm-iface.c b/libdm/ioctl/libdm-iface.c
index 33c4e37e..3294580b 100644
--- a/libdm/ioctl/libdm-iface.c
+++ b/libdm/ioctl/libdm-iface.c
@@ -1653,10 +1653,10 @@ static struct dm_ioctl *_do_dm_ioctl(struct dm_task *dmt, unsigned command,
 				    	    _cmd_data_v4[dmt->type].name,
 					    strerror(errno));
 			else
-				log_error("device-mapper: %s ioctl "
+				log_error("device-mapper: %s ioctl on %s "
 					  "failed: %s",
 					  _cmd_data_v4[dmt->type].name,
-					  strerror(errno));
+					  dmi->name, strerror(errno));
 
 			/*
 			 * It's sometimes worth retrying after EBUSY in case
diff --git a/man/lvconvert.8.in b/man/lvconvert.8.in
index 8750b8a2..cc0ece45 100644
--- a/man/lvconvert.8.in
+++ b/man/lvconvert.8.in
@@ -52,6 +52,14 @@ LogicalVolume[Path]...
 [\-\-version]
 LogicalVolume[Path] [PhysicalVolume[Path]...]
 
+.br
+.B lvconvert
+\-\-replace PhysicalVolume
+[\-h|\-?|\-\-help]
+[\-v|\-\-verbose]
+[\-\-version]
+LogicalVolume[Path] [PhysicalVolume[Path]...]
+
 .SH DESCRIPTION
 lvconvert is used to change the segment type (i.e. linear, mirror, etc) or
 characteristics of a logical volume.  For example, it can add or remove the
@@ -181,6 +189,14 @@ Use \-f if you do not want any replacement.  Additionally, you may use
 viz. activation/mirror_log_fault_policy or
 activation/mirror_device_fault_policy.
 .br
+
+.TP
+.I \-\-replace PhysicalVolume
+Remove the specified device (PhysicalVolume) and replace it with one that is
+available in the volume group or from the specific list provided.  This option
+is only available to RAID segment types (e.g. "raid1", "raid5", etc).
+.br
+
 .SH Examples
 "lvconvert -m1 vg00/lvol1"
 .br
@@ -270,6 +286,14 @@ Merge an image that was detached temporarily from its mirror with
 the '\-\-trackchanges' argument back into its original mirror and
 bring its contents back up-to-date.
 
+.br
+"lvconvert --replace /dev/sdb1 vg00/my_raid1 /dev/sdf1"
+.br
+Replace the physical volume "/dev/sdb1" in the RAID1 logical volume "my_raid1"
+with the specified physical volume "/dev/sdf1".  Had the argument "/dev/sdf1"
+been left out, lvconvert would attempt to find a suitable device from those
+available in the volume group.
+
 .SH SEE ALSO
 .BR lvm (8),
 .BR vgcreate (8),
diff --git a/tools/args.h b/tools/args.h
index 9f0e5794..8f116b72 100644
--- a/tools/args.h
+++ b/tools/args.h
@@ -55,6 +55,7 @@ arg(corelog_ARG, '\0', "corelog", NULL, 0)
 arg(mirrorlog_ARG, '\0', "mirrorlog", string_arg, 0)
 arg(splitmirrors_ARG, '\0', "splitmirrors", int_arg, 0)
 arg(trackchanges_ARG, '\0', "trackchanges", NULL, 0)
+arg(replace_ARG, '\0', "replace", string_arg, ARG_GROUPABLE)
 arg(repair_ARG, '\0', "repair", NULL, 0)
 arg(use_policies_ARG, '\0', "use-policies", NULL, 0)
 arg(monitor_ARG, '\0', "monitor", yes_no_arg, 0)
diff --git a/tools/commands.h b/tools/commands.h
index ca6d9f48..22a81197 100644
--- a/tools/commands.h
+++ b/tools/commands.h
@@ -100,6 +100,7 @@ xx(lvconvert,
    "[-m|--mirrors Mirrors [{--mirrorlog {disk|core|mirrored}|--corelog}]]\n"
    "\t[--type SegmentType]\n"
    "\t[--repair [--use-policies]]\n"
+   "\t[--replace PhysicalVolume]\n"
    "\t[-R|--regionsize MirrorLogRegionSize]\n"
    "\t[--alloc AllocationPolicy]\n"
    "\t[-b|--background]\n"
@@ -141,8 +142,8 @@ xx(lvconvert,
 
    alloc_ARG, background_ARG, chunksize_ARG, corelog_ARG, interval_ARG,
    merge_ARG, mirrorlog_ARG, mirrors_ARG, name_ARG, noudevsync_ARG,
-   regionsize_ARG, repair_ARG, snapshot_ARG, splitmirrors_ARG, trackchanges_ARG,
-   type_ARG, stripes_long_ARG, stripesize_ARG, test_ARG,
+   regionsize_ARG, repair_ARG, replace_ARG, snapshot_ARG, splitmirrors_ARG,
+   trackchanges_ARG, type_ARG, stripes_long_ARG, stripesize_ARG, test_ARG,
    use_policies_ARG, yes_ARG, force_ARG, zero_ARG)
 
 xx(lvcreate,
diff --git a/tools/lvconvert.c b/tools/lvconvert.c
index 0c423ebf..1b9f6f9b 100644
--- a/tools/lvconvert.c
+++ b/tools/lvconvert.c
@@ -48,6 +48,10 @@ struct lvconvert_params {
 	char **pvs;
 	struct dm_list *pvh;
 
+	int replace_pv_count;
+	char **replace_pvs;
+	struct dm_list *replace_pvh;
+
 	struct logical_volume *lv_to_poll;
 };
 
@@ -122,6 +126,9 @@ static int _lvconvert_name_params(struct lvconvert_params *lp,
 static int _read_params(struct lvconvert_params *lp, struct cmd_context *cmd,
 			int argc, char **argv)
 {
+	int i;
+	const char *tmp_str;
+	struct arg_value_group_list *group;
 	int region_size;
 	int pagesize = lvm_getpagesize();
 
@@ -243,7 +250,27 @@ static int _read_params(struct lvconvert_params *lp, struct cmd_context *cmd,
 						 SEG_CANNOT_BE_ZEROED) ?
 						"n" : "y"), "n");
 
-	} else {	/* Mirrors */
+	} else if (arg_count(cmd, replace_ARG)) { /* RAID device replacement */
+		lp->replace_pv_count = arg_count(cmd, replace_ARG);
+		lp->replace_pvs = dm_pool_alloc(cmd->mem, sizeof(char *) * lp->replace_pv_count);
+		if (!lp->replace_pvs)
+			return_0;
+
+		i = 0;
+		dm_list_iterate_items(group, &cmd->arg_value_groups) {
+			if (!grouped_arg_is_set(group->arg_values, replace_ARG))
+				continue;
+			if (!(tmp_str = grouped_arg_str_value(group->arg_values,
+							      replace_ARG,
+							      NULL))) {
+				log_error("Failed to get '--replace' argument");
+				return 0;
+			}
+			if (!(lp->replace_pvs[i++] = dm_pool_strdup(cmd->mem,
+								    tmp_str)))
+				return_0;
+		}
+	} else { /* Mirrors (and some RAID functions) */
 		if (arg_count(cmd, chunksize_ARG)) {
 			log_error("--chunksize is only available with "
 				  "snapshots");
@@ -309,7 +336,7 @@ static int _read_params(struct lvconvert_params *lp, struct cmd_context *cmd,
 			return_0;
 	}
 
-	if (activation() && lp->segtype->ops->target_present &&
+	if (activation() && lp->segtype && lp->segtype->ops->target_present &&
 	    !lp->segtype->ops->target_present(cmd, NULL, NULL)) {
 		log_error("%s: Required device-mapper target(s) not "
 			  "detected in your kernel", lp->segtype->name);
@@ -1455,6 +1482,9 @@ static int lvconvert_raid(struct logical_volume *lv, struct lvconvert_params *lp
 	if (arg_count(cmd, type_ARG))
 		return lv_raid_reshape(lv, lp->segtype);
 
+	if (arg_count(cmd, replace_ARG))
+		return lv_raid_replace(lv, lp->replace_pvh, lp->pvh);
+
 	log_error("Conversion operation not yet supported.");
 	return 0;
 }
@@ -1646,6 +1676,9 @@ static int _lvconvert_single(struct cmd_context *cmd, struct logical_volume *lv,
 		return ECMD_FAILED;
 	}
 
+	if (!lp->segtype)
+		lp->segtype = first_seg(lv)->segtype;
+
 	if (lp->merge) {
 		if (!lv_is_cow(lv)) {
 			log_error("Logical volume \"%s\" is not a snapshot",
@@ -1785,6 +1818,12 @@ static int lvconvert_single(struct cmd_context *cmd, struct lvconvert_params *lp
 	} else
 		lp->pvh = &lv->vg->pvs;
 
+	if (lp->replace_pv_count &&
+	    !(lp->replace_pvh = create_pv_list(cmd->mem, lv->vg,
+					       lp->replace_pv_count,
+					       lp->replace_pvs, 0)))
+			goto_bad;
+
 	lp->lv_to_poll = lv;
 	ret = _lvconvert_single(cmd, lv, lp);
 bad: