Btrfs: fix missing deleted items in btrfs_clean_quota_tree

Steps to reproduce:

	i=0
	ncases=100

	mkfs.btrfs <disk>
	mount <disk> <mnt>
	btrfs quota enable <mnt>
	btrfs qgroup create 2/1 <mnt>
	while [ $i -le $ncases ]
	do
		btrfs qgroup create 1/$i <mnt>
		btrfs qgroup assign 1/$i 2/1 <mnt>
		i=$(($i+1))
	done

	btrfs quota disable <mnt>
	umount <mnt>
	btrfsck <mnt>

You can also use the commands:
	btrfs-debug-tree <disk> | grep QGROUP

You will find there are still items existed.The reasons why this happens
is because the original code just checks slots[0]==0 and returns.
We try to fix it by deleting the leaf one by one.

Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

1 files changed, 21 insertions, 13 deletions

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 88ab785bbd73..f011d9b8ffb1 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -732,7 +732,9 @@ static int btrfs_clean_quota_tree(struct btrfs_trans_handle *trans,
 {
         struct btrfs_path *path;
         struct btrfs_key key;
+        struct extent_buffer *leaf = NULL;
         int ret;
+        int nr = 0;
 
         if (!root)
                 return -EINVAL;
@@ -741,24 +743,30 @@ static int btrfs_clean_quota_tree(struct btrfs_trans_handle *trans,
         if (!path)
                 return -ENOMEM;
 
-        while (1) {
-                key.objectid = 0;
-                key.offset = 0;
-                key.type = 0;
+        path->leave_spinning = 1;
 
-                path->leave_spinning = 1;
+        key.objectid = 0;
+        key.offset = 0;
+        key.type = 0;
+
+        while (1) {
                 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
-                if (ret > 0) {
-                        if (path->slots[0] == 0)
-                                break;
-                        path->slots[0]--;
-                } else if (ret < 0) {
+                if (ret < 0)
+                        goto out;
+                leaf = path->nodes[0];
+                nr = btrfs_header_nritems(leaf);
+                if (!nr)
                         break;
-                }
-
-                ret = btrfs_del_item(trans, root, path);
+                /*
+                 * delete the leaf one by one
+                 * since the whole tree is going
+                 * to be deleted.
+                 */
+                path->slots[0] = 0;
+                ret = btrfs_del_items(trans, root, path, 0, nr);
                 if (ret)
                         goto out;
+
                 btrfs_release_path(path);
         }
         ret = 0;