ovl: cleanup non-empty directories in ovl_indexdir_cleanup()

Teach ovl_indexdir_cleanup() to remove temp directories containing
whiteouts to prepare for using index dir instead of work dir for removing
merge directories.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

fs/overlayfs/namei.c

@@ -484,12 +484,6 @@ struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index)
 	return upper;
 }
 
-/* Is this a leftover from create/whiteout of directory index entry? */
-static bool ovl_is_temp_index(struct dentry *index)
-{
-	return index->d_name.name[0] == '#';
-}
-
 /*
  * Verify that an index entry name matches the origin file handle stored in
  * OVL_XATTR_ORIGIN and that origin file handle can be decoded to lower path.
@@ -507,11 +501,6 @@ int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index)
 	if (!d_inode(index))
 		return 0;
 
-	/* Cleanup leftover from index create/cleanup attempt */
-	err = -ESTALE;
-	if (ovl_is_temp_index(index))
-		goto fail;
-
 	err = -EINVAL;
 	if (index->d_name.len < sizeof(struct ovl_fb)*2)
 		goto fail;

fs/overlayfs/overlayfs.h

@@ -394,8 +394,8 @@ void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list);
 void ovl_cache_free(struct list_head *list);
 void ovl_dir_cache_free(struct inode *inode);
 int ovl_check_d_type_supported(struct path *realpath);
-void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
-			 struct dentry *dentry, int level);
+int ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
+			struct dentry *dentry, int level);
 int ovl_indexdir_cleanup(struct ovl_fs *ofs);
 
 /* inode.c */

fs/overlayfs/readdir.c

@@ -1071,14 +1071,13 @@ static void ovl_workdir_cleanup_recurse(struct path *path, int level)
 	ovl_cache_free(&list);
 }
 
-void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
+int ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
 			 struct dentry *dentry, int level)
 {
 	int err;
 
 	if (!d_is_dir(dentry) || level > 1) {
-		ovl_cleanup(dir, dentry);
-		return;
+		return ovl_cleanup(dir, dentry);
 	}
 
 	err = ovl_do_rmdir(dir, dentry);
@@ -1088,8 +1087,10 @@ void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
 		inode_unlock(dir);
 		ovl_workdir_cleanup_recurse(&path, level + 1);
 		inode_lock_nested(dir, I_MUTEX_PARENT);
-		ovl_cleanup(dir, dentry);
+		err = ovl_cleanup(dir, dentry);
 	}
+
+	return err;
 }
 
 int ovl_indexdir_cleanup(struct ovl_fs *ofs)
@@ -1128,6 +1129,13 @@ int ovl_indexdir_cleanup(struct ovl_fs *ofs)
 			index = NULL;
 			break;
 		}
+		/* Cleanup leftover from index create/cleanup attempt */
+		if (index->d_name.name[0] == '#') {
+			err = ovl_workdir_cleanup(dir, path.mnt, index, 1);
+			if (err)
+				break;
+			goto next;
+		}
 		err = ovl_verify_index(ofs, index);
 		if (!err) {
 			goto next;