btrfs: Fix oopsen when dropping empty tree.

Commit Message

Yan, Zheng Feb. 1, 2010, 2:41 a.m. UTC

None

Patch

diff -urp 1/fs/btrfs/extent-tree.c 2/fs/btrfs/extent-tree.c
--- 1/fs/btrfs/extent-tree.c	2010-01-22 12:16:34.203525744 +0800
+++ 2/fs/btrfs/extent-tree.c	2010-02-01 10:26:19.865562007 +0800
@@ -5402,10 +5402,6 @@  static noinline int walk_down_tree(struc
 	int ret;
 
 	while (level >= 0) {
-		if (path->slots[level] >=
-		    btrfs_header_nritems(path->nodes[level]))
-			break;
-
 		ret = walk_down_proc(trans, root, path, wc, lookup_info);
 		if (ret > 0)
 			break;
@@ -5413,6 +5409,10 @@  static noinline int walk_down_tree(struc
 		if (level == 0)
 			break;
 
+		if (path->slots[level] >=
+		    btrfs_header_nritems(path->nodes[level]))
+			break;
+
 		ret = do_walk_down(trans, root, path, wc, &lookup_info);
 		if (ret > 0) {
 			path->slots[level]++;