From: Chris Mason <chris.mason@oracle.com>
Date: Thu, 24 Apr 2008 14:54:32 +0000 (-0400)
Subject: Don't empty the middle buffer in push_nodes_for_insert
X-Git-Tag: upstream/0.20.rc1~275
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=8057a6c3e739fa09b1a9398c13e00fd3c70fe939;p=platform%2Fupstream%2Fbtrfs-progs.git

Don't empty the middle buffer in push_nodes_for_insert
---

diff --git a/ctree.c b/ctree.c
index 184d842..eb645da 100644
--- a/ctree.c
+++ b/ctree.c
@@ -27,7 +27,7 @@ static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
 		      struct btrfs_path *path, int data_size, int extend);
 static int push_node_left(struct btrfs_trans_handle *trans,
 			  struct btrfs_root *root, struct extent_buffer *dst,
-			  struct extent_buffer *src);
+			  struct extent_buffer *src, int empty);
 static int balance_node_right(struct btrfs_trans_handle *trans,
 			      struct btrfs_root *root,
 			      struct extent_buffer *dst_buf,
@@ -745,7 +745,7 @@ static int balance_level(struct btrfs_trans_handle *trans,
 	/* first, try to make some room in the middle buffer */
 	if (left) {
 		orig_slot += btrfs_header_nritems(left);
-		wret = push_node_left(trans, root, left, mid);
+		wret = push_node_left(trans, root, left, mid, 0);
 		if (wret < 0)
 			ret = wret;
 		if (btrfs_header_nritems(mid) < 2)
@@ -756,7 +756,7 @@ static int balance_level(struct btrfs_trans_handle *trans,
 	 * then try to empty the right most buffer into the middle
 	 */
 	if (right) {
-		wret = push_node_left(trans, root, mid, right);
+		wret = push_node_left(trans, root, mid, right, 1);
 		if (wret < 0 && wret != -ENOSPC)
 			ret = wret;
 		if (btrfs_header_nritems(right) == 0) {
@@ -899,7 +899,7 @@ static int noinline push_nodes_for_insert(struct btrfs_trans_handle *trans,
 				wret = 1;
 			else {
 				wret = push_node_left(trans, root,
-						      left, mid);
+						      left, mid, 0);
 			}
 		}
 		if (wret < 0)
@@ -1200,7 +1200,7 @@ static int fixup_low_keys(struct btrfs_trans_handle *trans,
  */
 static int push_node_left(struct btrfs_trans_handle *trans,
 			  struct btrfs_root *root, struct extent_buffer *dst,
-			  struct extent_buffer *src)
+			  struct extent_buffer *src, int empty)
 {
 	int push_items = 0;
 	int src_nritems;
@@ -1213,12 +1213,17 @@ static int push_node_left(struct btrfs_trans_handle *trans,
 	WARN_ON(btrfs_header_generation(src) != trans->transid);
 	WARN_ON(btrfs_header_generation(dst) != trans->transid);
 
+	if (!empty && src_nritems <= 2)
+		return 1;
+
 	if (push_items <= 0) {
 		return 1;
 	}
 
-	if (src_nritems < push_items)
-		push_items = src_nritems;
+	if (empty)
+		push_items = min(src_nritems, push_items);
+	else
+		push_items = min(src_nritems - 2, push_items);
 
 	copy_extent_buffer(dst, src,
 			   btrfs_node_key_ptr_offset(dst_nritems),