btrfs: stop referencing btrfs_delayed_tree_ref directly

We only ever need to use this to get the level of the tree block ref, so
use the btrfs_delayed_ref_owner() helper, which returns the level for
the given reference.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/backref.c

@@ -919,28 +919,29 @@ static int add_delayed_refs(const struct btrfs_fs_info *fs_info,
 		switch (node->type) {
 		case BTRFS_TREE_BLOCK_REF_KEY: {
 			/* NORMAL INDIRECT METADATA backref */
-			struct btrfs_delayed_tree_ref *ref;
 			struct btrfs_key *key_ptr = NULL;
+			/* The owner of a tree block ref is the level. */
+			int level = btrfs_delayed_ref_owner(node);
 
 			if (head->extent_op && head->extent_op->update_key) {
 				btrfs_disk_key_to_cpu(&key, &head->extent_op->key);
 				key_ptr = &key;
 			}
 
-			ref = btrfs_delayed_node_to_tree_ref(node);
 			ret = add_indirect_ref(fs_info, preftrees, node->ref_root,
-					       key_ptr, ref->level + 1,
-					       node->bytenr, count, sc,
-					       GFP_ATOMIC);
+					       key_ptr, level + 1, node->bytenr,
+					       count, sc, GFP_ATOMIC);
 			break;
 		}
 		case BTRFS_SHARED_BLOCK_REF_KEY: {
-			/* SHARED DIRECT METADATA backref */
-			struct btrfs_delayed_tree_ref *ref;
-
-			ref = btrfs_delayed_node_to_tree_ref(node);
+			/*
+			 * SHARED DIRECT METADATA backref
+			 *
+			 * The owner of a tree block ref is the level.
+			 */
+			int level = btrfs_delayed_ref_owner(node);
 
-			ret = add_direct_ref(fs_info, preftrees, ref->level + 1,
+			ret = add_direct_ref(fs_info, preftrees, level + 1,
 					     node->parent, node->bytenr, count,
 					     sc, GFP_ATOMIC);
 			break;

fs/btrfs/extent-tree.c

@@ -4865,16 +4865,16 @@ static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
 	struct btrfs_extent_inline_ref *iref;
 	struct btrfs_path *path;
 	struct extent_buffer *leaf;
-	struct btrfs_delayed_tree_ref *ref;
 	u32 size = sizeof(*extent_item) + sizeof(*iref);
 	u64 flags = extent_op->flags_to_set;
+	/* The owner of a tree block is the level. */
+	int level = btrfs_delayed_ref_owner(node);
 	bool skinny_metadata = btrfs_fs_incompat(fs_info, SKINNY_METADATA);
 
-	ref = btrfs_delayed_node_to_tree_ref(node);
-
 	extent_key.objectid = node->bytenr;
 	if (skinny_metadata) {
-		extent_key.offset = ref->level;
+		/* The owner of a tree block is the level. */
+		extent_key.offset = level;
 		extent_key.type = BTRFS_METADATA_ITEM_KEY;
 	} else {
 		extent_key.offset = node->num_bytes;
@@ -4907,7 +4907,7 @@ static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
 	} else {
 		block_info = (struct btrfs_tree_block_info *)(extent_item + 1);
 		btrfs_set_tree_block_key(leaf, block_info, &extent_op->key);
-		btrfs_set_tree_block_level(leaf, block_info, ref->level);
+		btrfs_set_tree_block_level(leaf, block_info, level);
 		iref = (struct btrfs_extent_inline_ref *)(block_info + 1);
 	}
 

include/trace/events/btrfs.h

@@ -16,7 +16,6 @@ struct extent_map;
 struct btrfs_file_extent_item;
 struct btrfs_ordered_extent;
 struct btrfs_delayed_ref_node;
-struct btrfs_delayed_tree_ref;
 struct btrfs_delayed_ref_head;
 struct btrfs_block_group;
 struct btrfs_free_cluster;