btrfs: zoned: make zone activation multi stripe capable

Currently activation of a zone only works if the block group isn't
spanning more than one zone.

This limitation is purely artificial and can be easily expanded to block
groups being places across multiple zones.

This is a preparation for allowing DUP and later more complex block-group
profiles on zoned btrfs.
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/zoned.c

@@ -1781,26 +1781,26 @@ bool btrfs_zone_activate(struct btrfs_block_group *block_group)
 	struct btrfs_device *device;
 	u64 physical;
 	bool ret;
+	int i;
 
 	if (!btrfs_is_zoned(block_group->fs_info))
 		return true;
 
 	map = block_group->physical_map;
-	/* Currently support SINGLE profile only */
-	ASSERT(map->num_stripes == 1);
-	device = map->stripes[0].dev;
-	physical = map->stripes[0].physical;
-
-	if (device->zone_info->max_active_zones == 0)
-		return true;
 
 	spin_lock(&block_group->lock);
-
 	if (block_group->zone_is_active) {
 		ret = true;
 		goto out_unlock;
 	}
 
+	for (i = 0; i < map->num_stripes; i++) {
+		device = map->stripes[i].dev;
+		physical = map->stripes[i].physical;
+
+		if (device->zone_info->max_active_zones == 0)
+			continue;
+
 		/* No space left */
 		if (block_group->alloc_offset == block_group->zone_capacity) {
 			ret = false;
@@ -1814,17 +1814,22 @@ bool btrfs_zone_activate(struct btrfs_block_group *block_group)
 		}
 
 		/* Successfully activated all the zones */
+		if (i == map->num_stripes - 1)
 			block_group->zone_is_active = 1;
 
+
+	}
 	spin_unlock(&block_group->lock);
 
+	if (block_group->zone_is_active) {
 		/* For the active block group list */
 		btrfs_get_block_group(block_group);
 
 		spin_lock(&fs_info->zone_active_bgs_lock);
-	ASSERT(list_empty(&block_group->active_bg_list));
-	list_add_tail(&block_group->active_bg_list, &fs_info->zone_active_bgs);
+		list_add_tail(&block_group->active_bg_list,
+			      &fs_info->zone_active_bgs);
 		spin_unlock(&fs_info->zone_active_bgs_lock);
+	}
 
 	return true;