Fix ENOTEMPTY check in btrfs_rmdir

The ENOTEMPTY check in btrfs_rmdir isn't reliable. It's possible that
the backward search finds . or .. at first, then some other directory
entry. In that case,  btrfs_rmdir delete . or .. improperly.  The
patch also fixes a fs_mutex unlock issue in  btrfs_rmdir.

--

Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index b74a831fab19cc511bee5d4dfbe19aecbad20d5a..7e4b2c1b4a5638b1a746bf582a41d0573f50f838 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -448,6 +448,9 @@ static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
        char *goodnames = "..";
        unsigned long nr;
 
+       if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
+               return -ENOTEMPTY;
+
        path = btrfs_alloc_path();
        BUG_ON(!path);
        mutex_lock(&root->fs_info->fs_mutex);
@@ -501,9 +504,9 @@ static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
 out:
        btrfs_release_path(root, path);
        btrfs_free_path(path);
-       mutex_unlock(&root->fs_info->fs_mutex);
        nr = trans->blocks_used;
        ret = btrfs_end_transaction(trans, root);
+       mutex_unlock(&root->fs_info->fs_mutex);
        btrfs_btree_balance_dirty(root, nr);
        if (ret && !err)
                err = ret;