Commit 023acb07 authored by Qu Wenruo's avatar Qu Wenruo Committed by David Sterba
Browse files

btrfs: backref: rename and move remove_backref_node() 



Also add comment explaining the cleanup progress, to differ it from
btrfs_backref_drop_node().

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 b0fe7078

fs/btrfs/backref.c

+45 −0
Original line number Diff line number Diff line
@@ -2514,3 +2514,48 @@ struct btrfs_backref_edge *btrfs_backref_alloc_edge( 
		cache->nr_edges++;

	return edge;

}



/*

 * Drop the backref node from cache, also cleaning up all its

 * upper edges and any uncached nodes in the path.

 *

 * This cleanup happens bottom up, thus the node should either

 * be the lowest node in the cache or a detached node.

 */

void btrfs_backref_cleanup_node(struct btrfs_backref_cache *cache,

				struct btrfs_backref_node *node)

{

	struct btrfs_backref_node *upper;

	struct btrfs_backref_edge *edge;



	if (!node)

		return;



	BUG_ON(!node->lowest && !node->detached);

	while (!list_empty(&node->upper)) {

		edge = list_entry(node->upper.next, struct btrfs_backref_edge,

				  list[LOWER]);

		upper = edge->node[UPPER];

		list_del(&edge->list[LOWER]);

		list_del(&edge->list[UPPER]);

		btrfs_backref_free_edge(cache, edge);



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

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

			btrfs_backref_drop_node(cache, node);

			node = upper;

			node->lowest = 1;

			continue;

		}

		/*

		 * Add the node to leaf node list if no other child block

		 * cached.

		 */

		if (list_empty(&upper->lower)) {

			list_add_tail(&upper->lower, &cache->leaves);

			upper->lowest = 1;

		}

	}



	btrfs_backref_drop_node(cache, node);

}

fs/btrfs/backref.h

+3 −0
Original line number Diff line number Diff line
@@ -350,4 +350,7 @@ static inline void btrfs_backref_drop_node(struct btrfs_backref_cache *tree, 
	btrfs_backref_free_node(tree, node);

}



void btrfs_backref_cleanup_node(struct btrfs_backref_cache *cache,

				struct btrfs_backref_node *node);



#endif

fs/btrfs/relocation.c

+5 −48
Original line number Diff line number Diff line
@@ -153,9 +153,6 @@ struct reloc_control { 
#define MOVE_DATA_EXTENTS	0

#define UPDATE_DATA_PTRS	1



static void remove_backref_node(struct btrfs_backref_cache *cache,

				struct btrfs_backref_node *node);



static void mark_block_processed(struct reloc_control *rc,

				 struct btrfs_backref_node *node)

{
@@ -186,13 +183,13 @@ static void backref_cache_cleanup(struct btrfs_backref_cache *cache) 
	while (!list_empty(&cache->detached)) {

		node = list_entry(cache->detached.next,

				  struct btrfs_backref_node, list);

		remove_backref_node(cache, node);

		btrfs_backref_cleanup_node(cache, node);

	}



	while (!list_empty(&cache->leaves)) {

		node = list_entry(cache->leaves.next,

				  struct btrfs_backref_node, lower);

		remove_backref_node(cache, node);

		btrfs_backref_cleanup_node(cache, node);

	}



	cache->last_trans = 0;
@@ -268,46 +265,6 @@ static struct btrfs_backref_node *walk_down_backref( 
	*index = 0;

	return NULL;

}

/*

 * remove a backref node from the backref cache

 */

static void remove_backref_node(struct btrfs_backref_cache *cache,

				struct btrfs_backref_node *node)

{

	struct btrfs_backref_node *upper;

	struct btrfs_backref_edge *edge;



	if (!node)

		return;



	BUG_ON(!node->lowest && !node->detached);

	while (!list_empty(&node->upper)) {

		edge = list_entry(node->upper.next, struct btrfs_backref_edge,

				  list[LOWER]);

		upper = edge->node[UPPER];

		list_del(&edge->list[LOWER]);

		list_del(&edge->list[UPPER]);

		btrfs_backref_free_edge(cache, edge);



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

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

			btrfs_backref_drop_node(cache, node);

			node = upper;

			node->lowest = 1;

			continue;

		}

		/*

		 * add the node to leaf node list if no other

		 * child block cached.

		 */

		if (list_empty(&upper->lower)) {

			list_add_tail(&upper->lower, &cache->leaves);

			upper->lowest = 1;

		}

	}



	btrfs_backref_drop_node(cache, node);

}



static void update_backref_node(struct btrfs_backref_cache *cache,

				struct btrfs_backref_node *node, u64 bytenr)
@@ -345,7 +302,7 @@ static int update_backref_cache(struct btrfs_trans_handle *trans, 
	while (!list_empty(&cache->detached)) {

		node = list_entry(cache->detached.next,

				  struct btrfs_backref_node, list);

		remove_backref_node(cache, node);

		btrfs_backref_cleanup_node(cache, node);

	}



	while (!list_empty(&cache->changed)) {
@@ -1120,7 +1077,7 @@ static noinline_for_stack struct btrfs_backref_node *build_backref_tree( 
			btrfs_backref_free_node(cache, lower);

		}



		remove_backref_node(cache, node);

		btrfs_backref_cleanup_node(cache, node);

		ASSERT(list_empty(&cache->useless_node) &&

		       list_empty(&cache->pending_edge));

		return ERR_PTR(err);
@@ -3103,7 +3060,7 @@ static int relocate_tree_block(struct btrfs_trans_handle *trans, 
	}

out:

	if (ret || node->level == 0 || node->cowonly)

		remove_backref_node(&rc->backref_cache, node);

		btrfs_backref_cleanup_node(&rc->backref_cache, node);

	return ret;

}