Commit b0fe7078 authored by Qu Wenruo's avatar Qu Wenruo Committed by David Sterba
Browse files

btrfs: backref: rename and move drop_backref_node() 



With extra comment for drop_backref_node() as it has some similarity
with remove_backref_node(), thus we need extra comment explaining the
difference.

Signed-off-by: default avatarQu Wenruo <wqu@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 741188d3

fs/btrfs/backref.h

+39 −0
Original line number Diff line number Diff line
@@ -311,4 +311,43 @@ static inline void btrfs_backref_free_edge(struct btrfs_backref_cache *cache, 
	}

}



static inline void btrfs_backref_unlock_node_buffer(

		struct btrfs_backref_node *node)

{

	if (node->locked) {

		btrfs_tree_unlock(node->eb);

		node->locked = 0;

	}

}



static inline void btrfs_backref_drop_node_buffer(

		struct btrfs_backref_node *node)

{

	if (node->eb) {

		btrfs_backref_unlock_node_buffer(node);

		free_extent_buffer(node->eb);

		node->eb = NULL;

	}

}



/*

 * Drop the backref node from cache without cleaning up its children

 * edges.

 *

 * This can only be called on node without parent edges.

 * The children edges are still kept as is.

 */

static inline void btrfs_backref_drop_node(struct btrfs_backref_cache *tree,

					   struct btrfs_backref_node *node)

{

	BUG_ON(!list_empty(&node->upper));



	btrfs_backref_drop_node_buffer(node);

	list_del(&node->list);

	list_del(&node->lower);

	if (!RB_EMPTY_NODE(&node->rb_node))

		rb_erase(&node->rb_node, &tree->rb_root);

	btrfs_backref_free_node(tree, node);

}



#endif

fs/btrfs/relocation.c

+7 −38
Original line number Diff line number Diff line
@@ -268,37 +268,6 @@ static struct btrfs_backref_node *walk_down_backref( 
	*index = 0;

	return NULL;

}



static void unlock_node_buffer(struct btrfs_backref_node *node)

{

	if (node->locked) {

		btrfs_tree_unlock(node->eb);

		node->locked = 0;

	}

}



static void drop_node_buffer(struct btrfs_backref_node *node)

{

	if (node->eb) {

		unlock_node_buffer(node);

		free_extent_buffer(node->eb);

		node->eb = NULL;

	}

}



static void drop_backref_node(struct btrfs_backref_cache *tree,

			      struct btrfs_backref_node *node)

{

	BUG_ON(!list_empty(&node->upper));



	drop_node_buffer(node);

	list_del(&node->list);

	list_del(&node->lower);

	if (!RB_EMPTY_NODE(&node->rb_node))

		rb_erase(&node->rb_node, &tree->rb_root);

	btrfs_backref_free_node(tree, node);

}



/*

 * remove a backref node from the backref cache

 */
@@ -322,7 +291,7 @@ static void remove_backref_node(struct btrfs_backref_cache *cache, 


		if (RB_EMPTY_NODE(&upper->rb_node)) {

			BUG_ON(!list_empty(&node->upper));

			drop_backref_node(cache, node);

			btrfs_backref_drop_node(cache, node);

			node = upper;

			node->lowest = 1;

			continue;
@@ -337,7 +306,7 @@ static void remove_backref_node(struct btrfs_backref_cache *cache, 
		}

	}



	drop_backref_node(cache, node);

	btrfs_backref_drop_node(cache, node);

}



static void update_backref_node(struct btrfs_backref_cache *cache,
@@ -2859,7 +2828,7 @@ static int do_relocation(struct btrfs_trans_handle *trans, 
				if (node->eb->start == bytenr)

					goto next;

			}

			drop_node_buffer(upper);

			btrfs_backref_drop_node_buffer(upper);

		}



		if (!upper->eb) {
@@ -2958,15 +2927,15 @@ static int do_relocation(struct btrfs_trans_handle *trans, 
		}

next:

		if (!upper->pending)

			drop_node_buffer(upper);

			btrfs_backref_drop_node_buffer(upper);

		else

			unlock_node_buffer(upper);

			btrfs_backref_unlock_node_buffer(upper);

		if (err)

			break;

	}



	if (!err && node->pending) {

		drop_node_buffer(node);

		btrfs_backref_drop_node_buffer(node);

		list_move_tail(&node->list, &rc->backref_cache.changed);

		node->pending = 0;

	}
@@ -4591,7 +4560,7 @@ int btrfs_reloc_cow_block(struct btrfs_trans_handle *trans, 
		BUG_ON(node->bytenr != buf->start &&

		       node->new_bytenr != buf->start);



		drop_node_buffer(node);

		btrfs_backref_drop_node_buffer(node);

		atomic_inc(&cow->refs);

		node->eb = cow;

		node->new_bytenr = cow->start;