1 files changed, 74 insertions, 52 deletions

diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c
index e4d467b..9bbac6d 100644
--- a/fs/btrfs/delayed-ref.c
+++ b/fs/btrfs/delayed-ref.c
@@ -161,35 +161,61 @@ static struct btrfs_delayed_ref_node *tree_insert(struct rb_root *root,
 	return NULL;
 }
 
+/* insert a new ref to head ref rbtree */
+static struct btrfs_delayed_ref_head *htree_insert(struct rb_root *root,
+						   struct rb_node *node)
+{
+	struct rb_node **p = &root->rb_node;
+	struct rb_node *parent_node = NULL;
+	struct btrfs_delayed_ref_head *entry;
+	struct btrfs_delayed_ref_head *ins;
+	u64 bytenr;
+
+	ins = rb_entry(node, struct btrfs_delayed_ref_head, href_node);
+	bytenr = ins->node.bytenr;
+	while (*p) {
+		parent_node = *p;
+		entry = rb_entry(parent_node, struct btrfs_delayed_ref_head,
+				 href_node);
+
+		if (bytenr < entry->node.bytenr)
+			p = &(*p)->rb_left;
+		else if (bytenr > entry->node.bytenr)
+			p = &(*p)->rb_right;
+		else
+			return entry;
+	}
+
+	rb_link_node(node, parent_node, p);
+	rb_insert_color(node, root);
+	return NULL;
+}
+
 /*
  * find an head entry based on bytenr. This returns the delayed ref
  * head if it was able to find one, or NULL if nothing was in that spot.
  * If return_bigger is given, the next bigger entry is returned if no exact
  * match is found.
  */
-static struct btrfs_delayed_ref_node *find_ref_head(struct rb_root *root,
-				  u64 bytenr,
-				  struct btrfs_delayed_ref_node **last,
-				  int return_bigger)
+static struct btrfs_delayed_ref_head *
+find_ref_head(struct rb_root *root, u64 bytenr,
+	      struct btrfs_delayed_ref_head **last, int return_bigger)
 {
 	struct rb_node *n;
-	struct btrfs_delayed_ref_node *entry;
+	struct btrfs_delayed_ref_head *entry;
 	int cmp = 0;
 
 again:
 	n = root->rb_node;
 	entry = NULL;
 	while (n) {
-		entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
-		WARN_ON(!entry->in_tree);
+		entry = rb_entry(n, struct btrfs_delayed_ref_head, href_node);
 		if (last)
 			*last = entry;
 
-		if (bytenr < entry->bytenr)
+		if (bytenr < entry->node.bytenr)
 			cmp = -1;
-		else if (bytenr > entry->bytenr)
-			cmp = 1;
-		else if (!btrfs_delayed_ref_is_head(entry))
+		else if (bytenr > entry->node.bytenr)
 			cmp = 1;
 		else
 			cmp = 0;
@@ -203,12 +229,12 @@ again:
 	}
 	if (entry && return_bigger) {
 		if (cmp > 0) {
-			n = rb_next(&entry->rb_node);
+			n = rb_next(&entry->href_node);
 			if (!n)
 				n = rb_first(root);
-			entry = rb_entry(n, struct btrfs_delayed_ref_node,
-					 rb_node);
-			bytenr = entry->bytenr;
+			entry = rb_entry(n, struct btrfs_delayed_ref_head,
+					 href_node);
+			bytenr = entry->node.bytenr;
 			return_bigger = 0;
 			goto again;
 		}
@@ -246,6 +272,12 @@ static inline void drop_delayed_ref(struct btrfs_trans_handle *trans,
 				    struct btrfs_delayed_ref_node *ref)
 {
 	rb_erase(&ref->rb_node, &delayed_refs->root);
+	if (btrfs_delayed_ref_is_head(ref)) {
+		struct btrfs_delayed_ref_head *head;
+
+		head = btrfs_delayed_node_to_head(ref);
+		rb_erase(&head->href_node, &delayed_refs->href_root);
+	}
 	ref->in_tree = 0;
 	btrfs_put_delayed_ref(ref);
 	delayed_refs->num_entries--;
@@ -379,42 +411,35 @@ int btrfs_find_ref_cluster(struct btrfs_trans_handle *trans,
 	int count = 0;
 	struct btrfs_delayed_ref_root *delayed_refs;
 	struct rb_node *node;
-	struct btrfs_delayed_ref_node *ref;
-	struct btrfs_delayed_ref_head *head;
+	struct btrfs_delayed_ref_head *head = NULL;
 
 	delayed_refs = &trans->transaction->delayed_refs;
-	if (start == 0) {
-		node = rb_first(&delayed_refs->root);
-	} else {
-		ref = NULL;
-		find_ref_head(&delayed_refs->root, start + 1, &ref, 1);
-		if (ref) {
-			node = &ref->rb_node;
-		} else
-			node = rb_first(&delayed_refs->root);
+	node = rb_first(&delayed_refs->href_root);
+
+	if (start) {
+		find_ref_head(&delayed_refs->href_root, start + 1, &head, 1);
+		if (head)
+			node = &head->href_node;
 	}
 again:
 	while (node && count < 32) {
-		ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
-		if (btrfs_delayed_ref_is_head(ref)) {
-			head = btrfs_delayed_node_to_head(ref);
-			if (list_empty(&head->cluster)) {
-				list_add_tail(&head->cluster, cluster);
-				delayed_refs->run_delayed_start =
-					head->node.bytenr;
-				count++;
-
-				WARN_ON(delayed_refs->num_heads_ready == 0);
-				delayed_refs->num_heads_ready--;
-			} else if (count) {
-				/* the goal of the clustering is to find extents
-				 * that are likely to end up in the same extent
-				 * leaf on disk.  So, we don't want them spread
-				 * all over the tree.  Stop now if we've hit
-				 * a head that was already in use
-				 */
-				break;
-			}
+		head = rb_entry(node, struct btrfs_delayed_ref_head, href_node);
+		if (list_empty(&head->cluster)) {
+			list_add_tail(&head->cluster, cluster);
+			delayed_refs->run_delayed_start =
+				head->node.bytenr;
+			count++;
+
+			WARN_ON(delayed_refs->num_heads_ready == 0);
+			delayed_refs->num_heads_ready--;
+		} else if (count) {
+			/* the goal of the clustering is to find extents
+			 * that are likely to end up in the same extent
+			 * leaf on disk.  So, we don't want them spread
+			 * all over the tree.  Stop now if we've hit
+			 * a head that was already in use
+			 */
+			break;
 		}
 		node = rb_next(node);
 	}
@@ -426,7 +451,7 @@ again:
 		 * clusters.  start from the beginning and try again
 		 */
 		start = 0;
-		node = rb_first(&delayed_refs->root);
+		node = rb_first(&delayed_refs->href_root);
 		goto again;
 	}
 	return 1;
@@ -612,6 +637,7 @@ static noinline void add_delayed_ref_head(struct btrfs_fs_info *fs_info,
 		 */
 		kmem_cache_free(btrfs_delayed_ref_head_cachep, head_ref);
 	} else {
+		htree_insert(&delayed_refs->href_root, &head_ref->href_node);
 		delayed_refs->num_heads++;
 		delayed_refs->num_heads_ready++;
 		delayed_refs->num_entries++;
@@ -869,14 +895,10 @@ int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info,
 struct btrfs_delayed_ref_head *
 btrfs_find_delayed_ref_head(struct btrfs_trans_handle *trans, u64 bytenr)
 {
-	struct btrfs_delayed_ref_node *ref;
 	struct btrfs_delayed_ref_root *delayed_refs;
 
 	delayed_refs = &trans->transaction->delayed_refs;
-	ref = find_ref_head(&delayed_refs->root, bytenr, NULL, 0);
-	if (ref)
-		return btrfs_delayed_node_to_head(ref);
-	return NULL;
+	return find_ref_head(&delayed_refs->href_root, bytenr, NULL, 0);
 }
 
 void btrfs_delayed_ref_exit(void)