Add support for m-way to n-way up-convert in RAID1 (no linear to n-way yet)

This patch adds the ability to upconvert a raid1 array - say from 2-way to 3-way. It does not yet support upconverting linear to n-way. The 'raid' device-mapper target allows for individual components (images) of an array to be specified for rebuild. This mechanism is used when adding new images to the array so that the new images can be resync'ed while the rest of the images in the array can remain 'in-sync'. (There is no mirror-on-mirror layering required.)
2025-10-21 15:33:18 +03:00 · 2011-08-18 19:41:21 +00:00
parent 6d04311efa
commit f439e65b64
6 changed files with 424 additions and 59 deletions
--- a/lib/metadata/raid_manip.c
+++ b/lib/metadata/raid_manip.c
@@ -195,6 +195,81 @@ static int raid_remove_top_layer(struct logical_volume *lv,
 	return 1;
 }

+/*
+ * clear_lv
+ * @lv
+ *
+ * If LV is active:
+ *        clear first block of device
+ * otherwise:
+ *        activate, clear, deactivate
+ *
+ * Returns: 1 on success, 0 on failure
+ */
+static int clear_lv(struct logical_volume *lv)
+{
+	int was_active = lv_is_active(lv);
+
+	if (!was_active && !activate_lv(lv->vg->cmd, lv)) {
+		log_error("Failed to activate %s for clearing",
+			  lv->name);
+		return 0;
+	}
+
+	log_verbose("Clearing metadata area of %s/%s",
+		    lv->vg->name, lv->name);
+	/*
+	 * Rather than wiping lv->size, we can simply
+	 * wipe '1' to remove the superblock of any previous
+	 * RAID devices.  It is much quicker.
+	 */
+	if (!set_lv(lv->vg->cmd, lv, 1, 0)) {
+		log_error("Failed to zero %s", lv->name);
+		return 0;
+	}
+
+	if (!was_active && !deactivate_lv(lv->vg->cmd, lv)) {
+		log_error("Failed to deactivate %s", lv->name);
+		return 0;
+	}
+
+	return 1;
+}
+
+/* Makes on-disk metadata changes */
+static int clear_lvs(struct dm_list *lv_list)
+{
+	struct lv_list *lvl;
+	struct volume_group *vg = NULL;
+
+	if (dm_list_empty(lv_list)) {
+		log_debug(INTERNAL_ERROR "Empty list of LVs given for clearing");
+		return 1;
+	}
+
+	dm_list_iterate_items(lvl, lv_list) {
+		if (!lv_is_visible(lvl->lv)) {
+			log_error(INTERNAL_ERROR
+				  "LVs must be set visible before clearing");
+			return 0;
+		}
+		vg = lvl->lv->vg;
+	}
+
+	/*
+	 * FIXME: only vg_[write|commit] if LVs are not already written
+	 * as visible in the LVM metadata (which is never the case yet).
+	 */
+	if (!vg || !vg_write(vg) || !vg_commit(vg))
+		return_0;
+
+	dm_list_iterate_items(lvl, lv_list)
+		if (!clear_lv(lvl->lv))
+			return 0;
+
+	return 1;
+}
+
 /*
 * _shift_and_rename_image_components
 * @seg: Top-level RAID segment
@@ -278,14 +353,234 @@ static int _shift_and_rename_image_components(struct lv_segment *seg)
 	return 1;
 }

+/*
+ * Create an LV of specified type.  Set visible after creation.
+ * This function does not make metadata changes.
+ */
+static int _alloc_image_component(struct logical_volume *lv,
+				  struct alloc_handle *ah, uint32_t first_area,
+				  uint32_t type, struct logical_volume **new_lv)
+{
+	uint64_t status;
+	size_t len = strlen(lv->name) + 32;
+	char img_name[len];
+	struct logical_volume *tmp_lv;
+	const struct segment_type *segtype;
+
+	if (type == RAID_META) {
+		if (dm_snprintf(img_name, len, "%s_rmeta_%%d", lv->name) < 0)
+			return_0;
+	} else if (type == RAID_IMAGE) {
+		if (dm_snprintf(img_name, len, "%s_rimage_%%d", lv->name) < 0)
+			return_0;
+	} else {
+		log_error(INTERNAL_ERROR
+			  "Bad type provided to _alloc_raid_component");
+		return 0;
+	}
+
+	if (!ah) {
+		first_area = 0;
+		log_error(INTERNAL_ERROR
+			  "Stand-alone %s area allocation not implemented",
+			  (type == RAID_META) ? "metadata" : "data");
+		return 0;
+	}
+
+	status = LVM_READ | LVM_WRITE | LV_NOTSYNCED | 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);
+		return 0;
+	}
+
+	segtype = get_segtype_from_string(lv->vg->cmd, "striped");
+	if (!lv_add_segment(ah, first_area, 1, tmp_lv, segtype, 0, status, 0)) {
+		log_error("Failed to add segment to LV, %s", img_name);
+		return 0;
+	}
+
+	lv_set_visible(tmp_lv);
+	*new_lv = tmp_lv;
+	return 1;
+}
+
+static int _alloc_image_components(struct logical_volume *lv,
+				   struct dm_list *pvs, uint32_t count,
+				   struct dm_list *new_meta_lvs,
+				   struct dm_list *new_data_lvs)
+{
+	uint32_t s;
+	struct lv_segment *seg = first_seg(lv);
+	struct alloc_handle *ah;
+	struct dm_list *parallel_areas;
+	struct logical_volume *tmp_lv;
+	struct lv_list *lvl_array;
+
+	lvl_array = dm_pool_alloc(lv->vg->vgmem,
+				  sizeof(*lvl_array) * count * 2);
+	if (!lvl_array)
+		return_0;
+
+	if (!(parallel_areas = build_parallel_areas_from_lv(lv, 0)))
+		return_0;
+
+	if (!(ah = allocate_extents(lv->vg, NULL, seg->segtype, 0, count, count,
+				    seg->region_size, lv->le_count, pvs,
+				    lv->alloc, parallel_areas)))
+		return_0;
+
+	for (s = 0; s < count; s++) {
+		/*
+		 * The allocation areas are grouped together.  First
+		 * come the rimage allocated areas, then come the metadata
+		 * allocated areas.  Thus, the metadata areas are pulled
+		 * from 's + count'.
+		 */
+		if (!_alloc_image_component(lv, ah, s + count,
+					    RAID_META, &tmp_lv))
+			return_0;
+		lvl_array[s + count].lv = tmp_lv;
+		dm_list_add(new_meta_lvs, &(lvl_array[s + count].list));
+
+		if (!_alloc_image_component(lv, ah, s, RAID_IMAGE, &tmp_lv))
+			return_0;
+		lvl_array[s].lv = tmp_lv;
+		dm_list_add(new_data_lvs, &(lvl_array[s].list));
+	}
+	alloc_destroy(ah);
+	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);
+	uint32_t s;
+	uint32_t old_count = lv_raid_image_count(lv);
+	uint32_t count = new_count - old_count;
+	struct cmd_context *cmd = lv->vg->cmd;
+	struct lv_segment *seg = first_seg(lv);
+	struct dm_list meta_lvs, data_lvs;
+	struct lv_list *lvl;
+	struct lv_segment_area *new_areas;

-	return 0;
+	dm_list_init(&meta_lvs); /* For image addition */
+	dm_list_init(&data_lvs); /* For image addition */
+
+	if (!seg_is_raid(seg)) {
+		log_error("Unable to add RAID images to %s of segment type %s",
+			  lv->name, seg->segtype->name);
+		return 0;
+	}
+
+	if (!_alloc_image_components(lv, pvs, count, &meta_lvs, &data_lvs)) {
+		log_error("Failed to allocate new image components");
+		return 0;
+	}
+
+	/* Metadata LVs must be cleared before being added to the array */
+	if (!clear_lvs(&meta_lvs))
+		goto fail;
+
+/*
+FIXME: It would be proper to activate the new LVs here, instead of having
+them activated by the suspend.  However, this causes residual device nodes
+to be left for these sub-lvs.
+	dm_list_iterate_items(lvl, &meta_lvs)
+		if (!do_correct_activate(lv, lvl->lv))
+			return_0;
+	dm_list_iterate_items(lvl, &data_lvs)
+		if (!do_correct_activate(lv, lvl->lv))
+			return_0;
+*/
+	/* Expand areas array */
+	if (!(new_areas = dm_pool_zalloc(lv->vg->cmd->mem,
+					 new_count * sizeof(*new_areas))))
+		goto fail;
+	memcpy(new_areas, seg->areas, seg->area_count * sizeof(*seg->areas));
+	seg->areas = new_areas;
+	seg->area_count = new_count;
+
+	/* Expand meta_areas array */
+	if (!(new_areas = dm_pool_zalloc(lv->vg->cmd->mem,
+					 new_count * sizeof(*new_areas))))
+		goto fail;
+	memcpy(new_areas, seg->meta_areas,
+	       seg->area_count * sizeof(*seg->meta_areas));
+	seg->meta_areas = new_areas;
+
+	/* Set segment areas for metadata sub_lvs */
+	s = old_count;
+	dm_list_iterate_items(lvl, &meta_lvs) {
+		log_debug("Adding %s to %s",
+			  lvl->lv->name, lv->name);
+		if (!set_lv_segment_area_lv(seg, s, lvl->lv, 0,
+					    lvl->lv->status)) {
+			log_error("Failed to add %s to %s",
+				  lvl->lv->name, lv->name);
+			goto fail;
+		}
+		s++;
+	}
+
+	/* Set segment areas for data sub_lvs */
+	s = old_count;
+	dm_list_iterate_items(lvl, &data_lvs) {
+		log_debug("Adding %s to %s",
+			  lvl->lv->name, lv->name);
+		if (!set_lv_segment_area_lv(seg, s, lvl->lv, 0,
+					    lvl->lv->status)) {
+			log_error("Failed to add %s to %s",
+				  lvl->lv->name, lv->name);
+			goto fail;
+		}
+		s++;
+	}
+
+	/*
+	 * FIXME: Failure handling during these points is harder.
+	 */
+	dm_list_iterate_items(lvl, &meta_lvs)
+		lv_set_hidden(lvl->lv);
+	dm_list_iterate_items(lvl, &data_lvs)
+		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(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(cmd, lv)) {
+		log_error("Failed to resume %s/%s after committing changes",
+			  lv->vg->name, lv->name);
+		return 0;
+	}
+
+	return 1;
+
+fail:
+	/* Cleanly remove newly allocated LVs that failed insertion attempt */
+
+	dm_list_iterate_items(lvl, &meta_lvs)
+		if (!lv_remove(lvl->lv))
+			return_0;
+	dm_list_iterate_items(lvl, &data_lvs)
+		if (!lv_remove(lvl->lv))
+			return_0;
+	return_0;
 }

 /*
@@ -386,7 +681,7 @@ static int raid_extract_images(struct logical_volume *lv, uint32_t new_count,
 		    (extract > 1) ? "images" : "image",
 		    lv->vg->name, lv->name);

-	lvl_array = dm_pool_alloc(lv->vg->cmd->mem,
+	lvl_array = dm_pool_alloc(lv->vg->vgmem,
 				  sizeof(*lvl_array) * extract * 2);
 	if (!lvl_array)
 		return_0;
@@ -429,56 +724,21 @@ static int raid_extract_images(struct logical_volume *lv, uint32_t new_count,
 	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)
+static int raid_remove_images(struct logical_volume *lv,
+			      uint32_t new_count, struct dm_list *pvs)
 {
-	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;

 	dm_list_init(&removal_list);

-	if (!seg_is_mirrored(seg)) {
-		log_error("Unable to change image count of non-mirrored RAID.");
+	if (!raid_extract_images(lv, new_count, pvs, 1,
+				 &removal_list, &removal_list)) {
+		log_error("Failed to extract images from %s/%s",
+			  lv->vg->name, lv->name);
 		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) {
-		if (!raid_extract_images(lv, new_count, pvs, 1,
-					 &removal_list, &removal_list)) {
-			log_error("Failed to extract images from %s/%s",
-				  lv->vg->name, lv->name);
-			return 0;
-		}
-	} else {
-		if (!raid_add_images(lv, new_count, pvs)) {
-			log_error("Failed to add images to %s/%s",
-				  lv->vg->name, lv->name);
-			return 0;
-		}
-	}
-
 	/* Convert to linear? */
 	if ((new_count == 1) && !raid_remove_top_layer(lv, &removal_list)) {
 		log_error("Failed to remove RAID layer after linear conversion");
@@ -532,6 +792,43 @@ int lv_raid_change_image_count(struct logical_volume *lv,
 	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)
+{
+	uint32_t old_count = lv_raid_image_count(lv);
+	struct lv_segment *seg = first_seg(lv);
+
+	if (!seg_is_mirrored(seg)) {
+		log_error("Unable to change image count of non-mirrored RAID.");
+		return 0;
+	}
+
+	if (old_count == new_count) {
+		log_error("%s/%s already has image count of %d",
+			  lv->vg->name, lv->name, new_count);
+		return 1;
+	}
+
+	if (old_count > new_count)
+		return raid_remove_images(lv, new_count, pvs);
+
+	return raid_add_images(lv, new_count, pvs);
+}
+
 int lv_raid_split(struct logical_volume *lv, const char *split_name,
 		  uint32_t new_count, struct dm_list *splittable_pvs)
 {