Permit snapshots of mirrors. (brassow)

WHATS_NEW

@@ -1,5 +1,6 @@
 Version 2.02.54 -
 =====================================
+  Permit snapshots of mirrors.
   Cleanup mimagetmp LV if allocation fails for new lvconvert mimage.
   Fix clvmd segfault when refresh_toolcontext fails.
   Remember to clear 'global lock held during cache refresh' state after use.

lib/activate/dev_manager.c

@@ -551,16 +551,17 @@ int dev_manager_mirror_percent(struct dev_manager *dm,
 {
 	char *name;
 	const char *dlid;
+	const char *suffix = (lv_is_origin(lv)) ? "real" : NULL;
 
 	/*
 	 * Build a name for the top layer.
 	 */
-	if (!(name = build_dm_name(dm->mem, lv->vg->name, lv->name, NULL)))
+	if (!(name = build_dm_name(dm->mem, lv->vg->name, lv->name, suffix)))
 		return_0;
 
 	/* FIXME dm_pool_free ? */
 
-	if (!(dlid = build_dlid(dm, lv->lvid.s, NULL))) {
+	if (!(dlid = build_dlid(dm, lv->lvid.s, suffix))) {
 		log_error("dlid build failed for %s", lv->name);
 		return 0;
 	}

lib/display/display.c

@@ -480,7 +480,7 @@ int lvdisplay_full(struct cmd_context *cmd,
 	struct lvinfo info;
 	int inkernel, snap_active = 0;
 	char uuid[64] __attribute((aligned(8)));
-	struct lv_segment *snap_seg = NULL;
+	struct lv_segment *snap_seg = NULL, *mirror_seg = NULL;
 	float snap_percent;	/* fused, fsize; */
 	percent_range_t percent_range;
 
@@ -563,6 +563,13 @@ int lvdisplay_full(struct cmd_context *cmd,
 			  display_size(cmd, (uint64_t) snap_seg->chunk_size));
 	}
 
+	if (lv->status & MIRRORED) {
+ 		mirror_seg = first_seg(lv);
+		log_print("Mirrored volumes       %" PRIu32, mirror_seg->area_count);
+		if (lv->status & CONVERTING)
+			log_print("LV type        Mirror undergoing conversion");
+	}
+
 	log_print("Segments               %u", dm_list_size(&lv->segments));
 
 /********* FIXME Stripes & stripesize for each segment

lib/metadata/lv_manip.c

@@ -2936,11 +2936,12 @@ int lv_create_single(struct volume_group *vg,
 					  "supported yet");
 				return 0;
 			}
-			if (org->status & MIRROR_IMAGE ||
-			    org->status & MIRROR_LOG ||
-			    org->status & MIRRORED) {
-				log_error("Snapshots and mirrors may not yet "
-					  "be mixed.");
+			if ((org->status & MIRROR_IMAGE) ||
+			    (org->status & MIRROR_LOG)) {
+				log_error("Snapshots of mirror %ss "
+					  "are not supported",
+					  (org->status & MIRROR_LOG) ?
+					  "log" : "image");
 				return 0;
 			}
 

lib/report/report.c

@@ -311,6 +311,11 @@ static int _lvstatus_disp(struct dm_report *rh __attribute((unused)), struct dm_
 		repstr[0] = 'p';
 	else if (lv->status & CONVERTING)
 		repstr[0] = 'c';
+	else if (lv->status & VIRTUAL)
+		repstr[0] = 'v';
+	/* Origin takes precedence over Mirror */
+	else if (lv_is_origin(lv))
+		repstr[0] = 'o';
 	else if (lv->status & MIRRORED) {
 		if (lv->status & MIRROR_NOTSYNCED)
 			repstr[0] = 'M';
@@ -323,10 +328,6 @@ static int _lvstatus_disp(struct dm_report *rh __attribute((unused)), struct dm_
 			repstr[0] = 'I';
 	else if (lv->status & MIRROR_LOG)
 		repstr[0] = 'l';
-	else if (lv->status & VIRTUAL)
-		repstr[0] = 'v';
-	else if (lv_is_origin(lv))
-		repstr[0] = 'o';
 	else if (lv_is_cow(lv))
 		repstr[0] = 's';
 	else

tools/lvconvert.c

@@ -713,6 +713,20 @@ static int _lvconvert_mirrors(struct cmd_context *cmd, struct logical_volume *lv
 				  "LV: use lvchange --resync first.");
 			return 0;
 		}
+
+		/*
+		 * We allow snapshots of mirrors, but for now, we
+		 * do not allow up converting mirrors that are under
+		 * snapshots.  The layering logic is somewhat complex,
+		 * and preliminary test show that the conversion can't
+		 * seem to get the correct %'age of completion.
+		 */
+		if (lv_is_origin(lv)) {
+			log_error("Can't add additional mirror images to "
+				  "mirrors that are under snapshots");
+			return 0;
+		}
+
 		/*
 		 * Log addition/removal should be done before the layer
 		 * insertion to make the end result consistent with
@@ -891,12 +905,6 @@ static int lvconvert_single(struct cmd_context *cmd, struct logical_volume *lv,
 		return ECMD_FAILED;
 	}
 
-	if (lv_is_origin(lv)) {
-		log_error("Can't convert logical volume \"%s\" under snapshot",
-			  lv->name);
-		return ECMD_FAILED;
-	}
-
 	if (lv_is_cow(lv)) {
 		log_error("Can't convert snapshot logical volume \"%s\"",
 			  lv->name);

tools/vgsplit.c

@@ -411,14 +411,15 @@ int vgsplit(struct cmd_context *cmd, int argc, char **argv)
 	if (!(_move_lvs(vg_from, vg_to)))
 		goto_bad;
 
-	/* Move required snapshots across */
-	if (!(_move_snapshots(vg_from, vg_to)))
-		goto_bad;
-
+	/* FIXME Separate the 'move' from the 'validation' to fix dev stacks */
 	/* Move required mirrors across */
 	if (!(_move_mirrors(vg_from, vg_to)))
 		goto_bad;
 
+	/* Move required snapshots across */
+	if (!(_move_snapshots(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");