[PATCH] LVM RAID: a couple more fixes

[Jonathan Brassow <jbrassow@redhat.com>]

Patch includes:
1) add new function 'raid_remove_top_layer' which will be useful
 to other conversion functions later (also cleans up code)
2) Add error messages if raid_[extract|add]_images fails
3) DO NOT activate sub_lv's between a suspend/resume
4) Add function prototypes to prevent compiler warnings when
 compiling with '--with-raid=shared'

Also, can someone provide insight on removing the 'sleep(1)'?  Without
it, I get "device in use: cannot deactivate" error messages - even
though it is /not/ in-use.

 brassow


Index: LVM2/lib/metadata/raid_manip.c
===================================================================
--- LVM2.orig/lib/metadata/raid_manip.c
+++ LVM2/lib/metadata/raid_manip.c
@@ -123,6 +123,63 @@ static int raid_in_sync(struct logical_v
 }
 
 /*
+ * raid_remove_top_layer
+ * @lv
+ * @removal_list
+ *
+ * Remove top layer of RAID LV in order to convert to linear.
+ * This function makes no on-disk changes.  The residual LVs
+ * returned in 'removal_list' must be freed by the caller.
+ *
+ * Returns: 1 on succes, 0 on failure
+ */
+static int raid_remove_top_layer(struct logical_volume *lv,
+				 struct dm_list *removal_list)
+{
+	struct lv_list *lvl_array, *lvl;
+	struct lv_segment *seg = first_seg(lv);
+
+	if (!seg_is_mirrored(seg)) {
+		log_error(INTERNAL_ERROR
+			  "Unable to remove RAID layer from segment type %s",
+			  seg->segtype->name);
+		return 0;
+	}
+
+	if (seg->area_count != 1) {
+		log_error(INTERNAL_ERROR
+			  "Unable to remove RAID layer when there"
+			  " is more than one sub-lv");
+		return 0;
+	}
+
+	lvl_array = dm_pool_alloc(lv->vg->vgmem, 2 * sizeof(*lvl));
+	if (!lvl_array) {
+		log_error("Memory allocation failed.");
+		return 0;
+	}
+
+	/* Add last metadata area to removal_list */
+	lvl_array[0].lv = seg_metalv(seg, 0);
+	lv_set_visible(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 and add residual LV to removal_list*/
+	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);
+	return 1;
+}
+
+/*
  * _shift_and_rename_image_components
  * @seg: Top-level RAID segment
  *
@@ -373,11 +430,10 @@ static int raid_extract_images(struct lo
 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;
+	struct lv_list *lvl;
 
 	dm_list_init(&removal_list);
 
@@ -392,34 +448,25 @@ int lv_raid_change_image_count(struct lo
 		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;
+	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) {
-		/* 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 ((new_count == 1) && !raid_remove_top_layer(lv, &removal_list)) {
+		log_error("Failed to remove RAID layer after linear conversion");
+		return 0;
 	}
 
 	if (!vg_write(lv->vg)) {
@@ -441,22 +488,9 @@ int lv_raid_change_image_count(struct lo
 	}
 
 	/*
-	 * Bring extracted LVs into existance, so there are no
-	 * conflicts for the main RAID device's resume
+	 * Resume original LV
+	 * This also resumes all other sub-lvs (including the extracted)
 	 */
-	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);
@@ -465,9 +499,17 @@ int lv_raid_change_image_count(struct lo
 
 	/*
 	 * Eliminate the extracted LVs
+	 * The extracted devices do not take on their new names
+	 * (i.e. *_extracted) unless we suspend/resume them.  It
+	 * is not strictly necessary, so we skip that step.
 	 */
 	if (!dm_list_empty(&removal_list)) {
 		dm_list_iterate_items(lvl, &removal_list) {
+			/*
+			 * FIXME: Remove 'sleep' that is necessary to prevent
+			 * "device in use" errors - udev not fast enough?
+			 */
+			sleep(1);
 			if (!deactivate_lv(lv->vg->cmd, lvl->lv))
 				return_0;
 			if (!lv_remove(lvl->lv))
Index: LVM2/lib/raid/raid.c
===================================================================
--- LVM2.orig/lib/raid/raid.c
+++ LVM2/lib/raid/raid.c
@@ -349,6 +349,20 @@ static struct segment_type *init_raid_se
 	return segtype;
 }
 
+#ifndef RAID_INTERNAL /* Shared */
+struct segment_type *init_raid1_segtype(struct cmd_context *cmd);
+struct segment_type *init_raid4_segtype(struct cmd_context *cmd);
+struct segment_type *init_raid5_segtype(struct cmd_context *cmd);
+struct segment_type *init_raid5_la_segtype(struct cmd_context *cmd);
+struct segment_type *init_raid5_ra_segtype(struct cmd_context *cmd);
+struct segment_type *init_raid5_ls_segtype(struct cmd_context *cmd);
+struct segment_type *init_raid5_rs_segtype(struct cmd_context *cmd);
+struct segment_type *init_raid6_segtype(struct cmd_context *cmd);
+struct segment_type *init_raid6_zr_segtype(struct cmd_context *cmd);
+struct segment_type *init_raid6_nr_segtype(struct cmd_context *cmd);
+struct segment_type *init_raid6_nc_segtype(struct cmd_context *cmd);
+#endif
+
 struct segment_type *init_raid1_segtype(struct cmd_context *cmd)
 {
 	struct segment_type *segtype;