btrfs-progs: mkfs: add support for the block group tree

Add the extent tree v2 table with the block group tree as a root, and
then create the empty root and use the proper root for cleanup up the
temporary block groups.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>

mkfs/common.c

@@ -39,6 +39,7 @@ static u64 reference_root_table[] = {
 	[MKFS_FS_TREE]		=	BTRFS_FS_TREE_OBJECTID,
 	[MKFS_CSUM_TREE]	=	BTRFS_CSUM_TREE_OBJECTID,
 	[MKFS_FREE_SPACE_TREE]	=	BTRFS_FREE_SPACE_TREE_OBJECTID,
+	[MKFS_BLOCK_GROUP_TREE]	=	BTRFS_BLOCK_GROUP_TREE_OBJECTID,
 };
 
 static int btrfs_write_empty_tree(int fd, struct btrfs_mkfs_config *cfg,
@@ -97,7 +98,8 @@ static int btrfs_create_tree_root(int fd, struct btrfs_mkfs_config *cfg,
 
 	for (i = 0; i < blocks_nr; i++) {
 		blk = blocks[i];
-		if (blk == MKFS_ROOT_TREE || blk == MKFS_CHUNK_TREE)
+		if (blk == MKFS_ROOT_TREE || blk == MKFS_CHUNK_TREE ||
+		    blk == MKFS_BLOCK_GROUP_TREE)
 			continue;
 
 		btrfs_set_root_bytenr(&root_item, cfg->blocks[blk]);
@@ -187,6 +189,50 @@ static int create_free_space_tree(int fd, struct btrfs_mkfs_config *cfg,
 	return 0;
 }
 
+static void write_block_group_item(struct extent_buffer *buf, u32 nr,
+				   u64 objectid, u64 offset, u64 used,
+				   u32 itemoff)
+{
+	struct btrfs_block_group_item *bg_item;
+	struct btrfs_disk_key disk_key;
+
+	btrfs_set_disk_key_objectid(&disk_key, objectid);
+	btrfs_set_disk_key_offset(&disk_key, offset);
+	btrfs_set_disk_key_type(&disk_key, BTRFS_BLOCK_GROUP_ITEM_KEY);
+	btrfs_set_item_key(buf, &disk_key, nr);
+	btrfs_set_item_offset(buf, nr, itemoff);
+	btrfs_set_item_size(buf, nr, sizeof(*bg_item));
+
+	bg_item = btrfs_item_ptr(buf, nr, struct btrfs_block_group_item);
+	btrfs_set_block_group_used(buf, bg_item, used);
+	btrfs_set_block_group_flags(buf, bg_item, BTRFS_BLOCK_GROUP_SYSTEM);
+	btrfs_set_block_group_chunk_objectid(buf, bg_item,
+					     BTRFS_FIRST_CHUNK_TREE_OBJECTID);
+}
+
+static int create_block_group_tree(int fd, struct btrfs_mkfs_config *cfg,
+				   struct extent_buffer *buf,
+				   u64 bg_offset, u64 bg_size, u64 bg_used)
+{
+	int ret;
+
+	memset(buf->data + sizeof(struct btrfs_header), 0,
+		cfg->nodesize - sizeof(struct btrfs_header));
+	write_block_group_item(buf, 0, bg_offset, bg_size, bg_used,
+			       cfg->leaf_data_size -
+			       sizeof(struct btrfs_block_group_item));
+	btrfs_set_header_bytenr(buf, cfg->blocks[MKFS_BLOCK_GROUP_TREE]);
+	btrfs_set_header_owner(buf, BTRFS_BLOCK_GROUP_TREE_OBJECTID);
+	btrfs_set_header_nritems(buf, 1);
+	csum_tree_block_size(buf, btrfs_csum_type_size(cfg->csum_type), 0,
+			     cfg->csum_type);
+	ret = pwrite(fd, buf->data, cfg->nodesize,
+		     cfg->blocks[MKFS_BLOCK_GROUP_TREE]);
+	if (ret != cfg->nodesize)
+		return ret < 0 ? -errno : -EIO;
+	return 0;
+}
+
 /*
  * @fs_uuid - if NULL, generates a UUID, returns back the new filesystem UUID
  *
@@ -239,11 +285,19 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 	bool add_block_group = true;
 	bool free_space_tree = !!(cfg->runtime_features &
 				  BTRFS_RUNTIME_FEATURE_FREE_SPACE_TREE);
+	bool extent_tree_v2 = !!(cfg->features &
+				 BTRFS_FEATURE_INCOMPAT_EXTENT_TREE_V2);
 
 	/* Don't include the free space tree in the blocks to process. */
 	if (!free_space_tree)
 		blocks_nr--;
 
+	if (extent_tree_v2) {
+		blocks = extent_tree_v2_blocks;
+		blocks_nr = ARRAY_SIZE(extent_tree_v2_blocks);
+		add_block_group = false;
+	}
+
 	if ((cfg->features & BTRFS_FEATURE_INCOMPAT_ZONED)) {
 		system_group_offset = cfg->zone_size * BTRFS_NR_SB_LOG_ZONES;
 		system_group_size = cfg->zone_size;
@@ -300,6 +354,12 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 		btrfs_set_super_compat_ro_flags(&super, ro_flags);
 		btrfs_set_super_cache_generation(&super, 0);
 	}
+	if (extent_tree_v2) {
+		btrfs_set_super_block_group_root(&super,
+						 cfg->blocks[MKFS_BLOCK_GROUP_TREE]);
+		btrfs_set_super_block_group_root_generation(&super, 1);
+		btrfs_set_super_block_group_root_level(&super, 0);
+	}
 	if (cfg->label)
 		__strncpy_null(super.label, cfg->label, BTRFS_LABEL_SIZE - 1);
 
@@ -331,25 +391,12 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 
 		/* Add the block group item for our temporary chunk. */
 		if (cfg->blocks[blk] > system_group_offset && add_block_group) {
-			struct btrfs_block_group_item *bg_item;
+			itemoff -= sizeof(struct btrfs_block_group_item);
-
+			write_block_group_item(buf, nritems,
+					       system_group_offset,
+					       system_group_size, total_used,
+					       itemoff);
 			add_block_group = false;
-
-			itemoff -= sizeof(*bg_item);
-			btrfs_set_disk_key_objectid(&disk_key, system_group_offset);
-			btrfs_set_disk_key_offset(&disk_key, system_group_size);
-			btrfs_set_disk_key_type(&disk_key, BTRFS_BLOCK_GROUP_ITEM_KEY);
-			btrfs_set_item_key(buf, &disk_key, nritems);
-			btrfs_set_item_offset(buf, nritems, itemoff);
-			btrfs_set_item_size(buf, nritems, sizeof(*bg_item));
-
-			bg_item = btrfs_item_ptr(buf, nritems,
-						 struct btrfs_block_group_item);
-			btrfs_set_block_group_used(buf, bg_item, total_used);
-			btrfs_set_block_group_flags(buf, bg_item,
-						    BTRFS_BLOCK_GROUP_SYSTEM);
-			btrfs_set_block_group_chunk_objectid(buf, bg_item,
-					BTRFS_FIRST_CHUNK_TREE_OBJECTID);
 			nritems++;
 		}
 
@@ -565,6 +612,14 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 			goto out;
 	}
 
+	if (extent_tree_v2) {
+		ret = create_block_group_tree(fd, cfg, buf,
+					      system_group_offset,
+					      system_group_size, total_used);
+		if (ret)
+			goto out;
+	}
+
 	/* and write out the super block */
 	memset(buf->data, 0, BTRFS_SUPER_INFO_SIZE);
 	memcpy(buf->data, &super, sizeof(super));

mkfs/common.h

@@ -51,6 +51,7 @@ enum btrfs_mkfs_block {
 	MKFS_FS_TREE,
 	MKFS_CSUM_TREE,
 	MKFS_FREE_SPACE_TREE,
+	MKFS_BLOCK_GROUP_TREE,
 	MKFS_BLOCK_COUNT
 };
 
@@ -69,6 +70,17 @@ static const enum btrfs_mkfs_block extent_tree_v1_blocks[] = {
 	MKFS_FREE_SPACE_TREE,
 };
 
+static const enum btrfs_mkfs_block extent_tree_v2_blocks[] = {
+	MKFS_ROOT_TREE,
+	MKFS_EXTENT_TREE,
+	MKFS_CHUNK_TREE,
+	MKFS_DEV_TREE,
+	MKFS_FS_TREE,
+	MKFS_CSUM_TREE,
+	MKFS_FREE_SPACE_TREE,
+	MKFS_BLOCK_GROUP_TREE,
+};
+
 struct btrfs_mkfs_config {
 	/* Label of the new filesystem */
 	const char *label;

mkfs/main.c

@@ -299,6 +299,11 @@ static int recow_roots(struct btrfs_trans_handle *trans,
 	ret = __recow_root(trans, info->dev_root);
 	if (ret)
 		return ret;
+        if (btrfs_fs_incompat(info, EXTENT_TREE_V2)) {
+		ret = __recow_root(trans, info->block_group_root);
+		if (ret)
+			return ret;
+        }
 	ret = recow_global_roots(trans);
 	if (ret)
 		return ret;