NFSv2/v3/v4: A patch by Greg Banks that fixes the "VFS: Busy inodes after unmount."

     problem.

fs/nfs/dir.c

@@ -666,6 +666,11 @@ static int nfs_dentry_delete(struct dentry *dentry)
 		/* Unhash it, so that ->d_iput() would be called */
 		return 1;
 	}
+	if (!(dentry->d_sb->s_flags & MS_ACTIVE)) {
+		/* Unhash it, so that ancestors of killed async unlink
+		 * files will be cleaned up during umount */
+		return 1;
+	}
 	return 0;
 
 }