btrfs: pass struct rb_simple_node pointer directly in rb_simple_insert()

Replace struct embedding with union to enable safe type conversion in
btrfs_backref_node, tree_block and mapping_node.

Adjust function calls to use the new unified API, eliminating redundant
parameters.

Signed-off-by: Pan Chuang <panchuang@vivo.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

4 files changed, 38 insertions, 26 deletions

diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index d011c64243c0..a4e0e2c3ea7d 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -3566,7 +3566,7 @@ int btrfs_backref_finish_upper_links(struct btrfs_backref_cache *cache,
 
 	ASSERT(start->checked);
 
-	rb_node = rb_simple_insert(&cache->rb_root, start->bytenr, &start->rb_node);
+	rb_node = rb_simple_insert(&cache->rb_root, &start->simple_node);
 	if (rb_node)
 		btrfs_backref_panic(cache->fs_info, start->bytenr, -EEXIST);
 
@@ -3617,8 +3617,7 @@ int btrfs_backref_finish_upper_links(struct btrfs_backref_cache *cache,
 			return -EUCLEAN;
 		}
 
-		rb_node = rb_simple_insert(&cache->rb_root, upper->bytenr,
-					   &upper->rb_node);
+		rb_node = rb_simple_insert(&cache->rb_root, &upper->simple_node);
 		if (unlikely(rb_node)) {
 			btrfs_backref_panic(cache->fs_info, upper->bytenr, -EEXIST);
 			return -EUCLEAN;
diff --git a/fs/btrfs/backref.h b/fs/btrfs/backref.h
index 507cfb35a23c..61f53825226d 100644
--- a/fs/btrfs/backref.h
+++ b/fs/btrfs/backref.h
@@ -313,10 +313,15 @@ int btrfs_backref_iter_next(struct btrfs_backref_iter *iter);
  * Represent a tree block in the backref cache
  */
 struct btrfs_backref_node {
-	struct {
-		struct rb_node rb_node;
-		u64 bytenr;
-	}; /* Use rb_simple_node for search/insert */
+	union{
+		/* Use rb_simple_node for search/insert */
+		struct {
+			struct rb_node rb_node;
+			u64 bytenr;
+		};
+
+		struct rb_simple_node simple_node;
+	};
 
 	/*
 	 * This is a sanity check, whenever we COW a block we will update
diff --git a/fs/btrfs/misc.h b/fs/btrfs/misc.h
index 0d599fd847c9..e28bca1b3de5 100644
--- a/fs/btrfs/misc.h
+++ b/fs/btrfs/misc.h
@@ -119,8 +119,8 @@ static inline struct rb_node *rb_simple_search_first(const struct rb_root *root,
 	return ret;
 }
 
-static inline struct rb_node *rb_simple_insert(struct rb_root *root, u64 bytenr,
-					       struct rb_node *node)
+static inline struct rb_node *rb_simple_insert(struct rb_root *root,
+					       struct rb_simple_node *simple_node)
 {
 	struct rb_node **p = &root->rb_node;
 	struct rb_node *parent = NULL;
@@ -130,16 +130,16 @@ static inline struct rb_node *rb_simple_insert(struct rb_root *root, u64 bytenr,
 		parent = *p;
 		entry = rb_entry(parent, struct rb_simple_node, rb_node);
 
-		if (bytenr < entry->bytenr)
+		if (simple_node->bytenr < entry->bytenr)
 			p = &(*p)->rb_left;
-		else if (bytenr > entry->bytenr)
+		else if (simple_node->bytenr > entry->bytenr)
 			p = &(*p)->rb_right;
 		else
 			return parent;
 	}
 
-	rb_link_node(node, parent, p);
-	rb_insert_color(node, root);
+	rb_link_node(&simple_node->rb_node, parent, p);
+	rb_insert_color(&simple_node->rb_node, root);
 	return NULL;
 }
 
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 02086191630d..0b73f58db33f 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -90,10 +90,15 @@
  * map address of tree root to tree
  */
 struct mapping_node {
-	struct {
-		struct rb_node rb_node;
-		u64 bytenr;
-	}; /* Use rb_simle_node for search/insert */
+	union {
+		/* Use rb_simple_node for search/insert */
+		struct {
+			struct rb_node rb_node;
+			u64 bytenr;
+		};
+
+		struct rb_simple_node simple_node;
+	};
 	void *data;
 };
 
@@ -106,10 +111,15 @@ struct mapping_tree {
  * present a tree block to process
  */
 struct tree_block {
-	struct {
-		struct rb_node rb_node;
-		u64 bytenr;
-	}; /* Use rb_simple_node for search/insert */
+	union {
+		/* Use rb_simple_node for search/insert */
+		struct {
+			struct rb_node rb_node;
+			u64 bytenr;
+		};
+
+		struct rb_simple_node simple_node;
+	};
 	u64 owner;
 	struct btrfs_key key;
 	u8 level;
@@ -480,8 +490,7 @@ static int __add_reloc_root(struct btrfs_root *root)
 	node->data = root;
 
 	spin_lock(&rc->reloc_root_tree.lock);
-	rb_node = rb_simple_insert(&rc->reloc_root_tree.rb_root,
-				   node->bytenr, &node->rb_node);
+	rb_node = rb_simple_insert(&rc->reloc_root_tree.rb_root, &node->simple_node);
 	spin_unlock(&rc->reloc_root_tree.lock);
 	if (rb_node) {
 		btrfs_err(fs_info,
@@ -564,8 +573,7 @@ static int __update_reloc_root(struct btrfs_root *root)
 
 	spin_lock(&rc->reloc_root_tree.lock);
 	node->bytenr = root->node->start;
-	rb_node = rb_simple_insert(&rc->reloc_root_tree.rb_root,
-				   node->bytenr, &node->rb_node);
+	rb_node = rb_simple_insert(&rc->reloc_root_tree.rb_root, &node->simple_node);
 	spin_unlock(&rc->reloc_root_tree.lock);
 	if (rb_node)
 		btrfs_backref_panic(fs_info, node->bytenr, -EEXIST);
@@ -3155,7 +3163,7 @@ static int add_tree_block(struct reloc_control *rc,
 	block->key_ready = false;
 	block->owner = owner;
 
-	rb_node = rb_simple_insert(blocks, block->bytenr, &block->rb_node);
+	rb_node = rb_simple_insert(blocks, &block->simple_node);
 	if (rb_node)
 		btrfs_backref_panic(rc->extent_root->fs_info, block->bytenr,
 				    -EEXIST);