Add mirror_seg pointer to lv_segment struct. (incomplete & untested)

WHATS_NEW

@@ -1,5 +1,6 @@
 Version 2.02.00 - 
 ===================================
+  Add mirror_seg pointer to lv_segment struct.
   Only keep a device open if it's known to belong to a locked VG.
   Fix lvdisplay to show all mirror destinations.
   Replacement suspend code using libdevmapper dependency tree.

lib/activate/dev_manager.c

@@ -2164,6 +2164,7 @@ static int _fill_in_active_list(struct dev_manager *dm, struct volume_group *vg)
 
 static int _action_activate(struct dev_manager *dm, struct logical_volume *lv)
 {
+	// Replace with deptree code for lv + known deps only.
 	if (!_scan_existing_devices(dm)) {
 		stack;
 		return 0;

lib/metadata/lv_manip.c

@@ -97,10 +97,13 @@ struct lv_segment *alloc_lv_segment(struct dm_pool *mem,
 	seg->region_size = region_size;
 	seg->extents_copied = extents_copied;
 	seg->log_lv = log_lv;
+	seg->mirror_seg = NULL;
 	list_init(&seg->tags);
 
-	if (log_lv)
+	if (log_lv) {
 		log_lv->status |= MIRROR_LOG;
+		find_seg_by_le(log_lv, 0)->mirror_seg = seg;
+	}
 
 	return seg;
 }
@@ -485,6 +488,9 @@ static int _setup_alloced_segment(struct logical_volume *lv, uint32_t status,
 
 	area_multiple = segtype_is_striped(segtype) ? area_count : 1;
 
+	/* FIXME Shouldn't log_lv always be NULL here? */
+	/* (As we set up log segments elsewhere) */
+
 	if (!(seg = alloc_lv_segment(lv->vg->cmd->mem, segtype, lv,
 				     lv->le_count,
 				     aa[0].len * area_multiple,
@@ -1059,8 +1065,10 @@ int lv_add_mirror_segment(struct alloc_handle *ah,
 		return 0;
 	}
 
-	for (m = 0; m < mirrors; m++)
+	for (m = 0; m < mirrors; m++) {
 		set_lv_segment_area_lv(seg, m, sub_lvs[m], 0, MIRROR_IMAGE);
+		find_seg_by_le(sub_lvs[m], 0)->mirror_seg = seg;
+	}
 
 	list_add(&lv->segments, &seg->list);
 	lv->le_count += ah->total_area_len;

lib/metadata/merge.c

@@ -85,6 +85,40 @@ int check_lv_segments(struct logical_volume *lv)
 			r = 0;
 		}
 
+		if (seg->log_lv) {
+			if (!seg_is_mirrored(seg)) {
+				log_error("LV %s: segment %u has log LV but "
+					  "is not mirrored",
+					  lv->name, seg_count);
+				r = 0;
+			}
+
+			if (!(seg->log_lv->status & MIRROR_LOG)) {
+				log_error("LV %s: segment %u log LV %s is not "
+					  "a mirror log",
+					   lv->name, seg_count, seg->log_lv->name);
+				r = 0;
+			}
+
+			if (!find_seg_by_le(seg->log_lv, 0) ||
+			    find_seg_by_le(seg->log_lv, 0)->mirror_seg != seg) {
+				log_error("LV %s: segment %u log LV does not "
+					  "point back to mirror segment",
+					   lv->name, seg_count);
+				r = 0;
+			}
+		}
+
+		if (seg->status & MIRROR_IMAGE) {
+			if (!seg->mirror_seg ||
+			    !seg_is_mirrored(seg->mirror_seg)) {
+				log_error("LV %s: segment %u mirror image "
+					  "is not mirrored",
+					  lv->name, seg_count);
+				r = 0;
+			}
+		}
+
 		for (s = 0; s < seg->area_count; s++) {
 			if (seg_type(seg, s) == AREA_UNASSIGNED) {
 				log_error("LV %s: segment %u has unassigned "
@@ -109,6 +143,18 @@ int check_lv_segments(struct logical_volume *lv)
 						  lv->name, seg_count, s);
 					r = 0;
 				}
+
+				if (seg_lv(seg, s) &&
+				    (seg_lv(seg, s)->status & MIRROR_IMAGE) &&
+				    (find_seg_by_le(seg_lv(seg, s),
+						    seg_le(seg, s))->mirror_seg
+							!= seg)) {
+					log_error("LV %s: segment %u mirror "
+						  "image %u missing mirror ptr",
+						  lv->name, seg_count, s);
+					r = 0;
+				}
+
 /* FIXME I don't think this ever holds?
 				if (seg_le(seg, s) != le) {
 					log_error("LV %s: segment %u has "

lib/metadata/metadata.h

@@ -251,6 +251,7 @@ struct lv_segment {
 	uint32_t region_size;	/* For mirrors - in sectors */
 	uint32_t extents_copied;
 	struct logical_volume *log_lv;
+	struct lv_segment *mirror_seg;
 
 	struct list tags;
 
@@ -559,6 +560,10 @@ int create_mirror_layers(struct alloc_handle *ah,
 			 struct logical_volume *log_lv);
 int remove_mirror_images(struct lv_segment *mirrored_seg, uint32_t num_mirrors);
 int remove_all_mirror_images(struct logical_volume *lv);
+/*
+ * Given mirror image or mirror log segment, find corresponding mirror segment 
+ */
+struct lv_segment *find_mirror_seg(struct lv_segment *seg);
 
 int insert_pvmove_mirrors(struct cmd_context *cmd,
 			  struct logical_volume *lv_mirr,

lib/metadata/mirror.c

@@ -22,6 +22,11 @@
 #include "lv_alloc.h"
 #include "lvm-string.h"
 
+struct lv_segment *find_mirror_seg(struct lv_segment *seg)
+{
+	return seg->mirror_seg;
+}
+
 /*
  * Ensure region size is compatible with volume size.
  */
@@ -149,8 +154,8 @@ int create_mirror_layers(struct alloc_handle *ah,
 	for (m = 0; m < num_mirrors; m++) {
 		if (!(img_lvs[m] = lv_create_empty(lv->vg->fid, img_name,
 					     NULL, LVM_READ | LVM_WRITE,
-					     ALLOC_INHERIT, 0, lv->vg))) {\
+					     ALLOC_INHERIT, 0, lv->vg))) {
-			log_error("Aborting. Failed to create submirror LV. "
+			log_error("Aborting. Failed to create mirror image LV. "
 				  "Remove new LV and retry.");
 			return 0;
 		}
@@ -159,7 +164,7 @@ int create_mirror_layers(struct alloc_handle *ah,
 				    get_segtype_from_string(lv->vg->cmd,
 							    "striped"),
 				    0, NULL, 0, 0, 0, NULL)) {
-			log_error("Aborting. Failed to add submirror segment "
+			log_error("Aborting. Failed to add mirror image segment "
 				  "to %s. Remove new LV and retry.",
 				  img_lvs[m]->name);
 			return 0;