From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932147Ab1FUBin (ORCPT ); Mon, 20 Jun 2011 21:38:43 -0400 Received: from mail09.linbit.com ([212.69.161.110]:56135 "EHLO mail09.linbit.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932082Ab1FUBil (ORCPT ); Mon, 20 Jun 2011 21:38:41 -0400 Subject: Re: [PATCH] xattr: Fix error results for non-existent / invisible attributes From: Andreas Gruenbacher To: Christoph Hellwig Cc: Al Viro , linux-kernel@vger.kernel.org, Andrew Morton , linux-fsdevel@vger.kernel.org In-Reply-To: <20110620080921.GA23159@infradead.org> References: <201105271450.37089.agruen@kernel.org> <20110620080921.GA23159@infradead.org> Content-Type: text/plain; charset="UTF-8" Date: Tue, 21 Jun 2011 03:34:17 +0200 Message-ID: <1308620057.2983.17.camel@schurl.linbit> Mime-Version: 1.0 X-Mailer: Evolution 3.0.2 (3.0.2-2.fc15) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2011-06-20 at 04:09 -0400, Christoph Hellwig wrote: > On Fri, May 27, 2011 at 02:50:36PM +0200, Andreas Gruenbacher wrote: > > Return -ENODATA when trying to read a user.* attribute which cannot > > exist: user space otherwise does not have a reasonable way to > > distinguish between non-existent and inaccessible attributes. > > > > Likewise, return -ENODATA when an unprivileged process tries to read a > > trusted.* attribute: to unprivileged processes, those attributes are > > invisible (listxattr() won't include them). > > This breaks xfstests 062. The test does a "getfattr -n " for an attribute which cannot exist. The kernel now returns ENODATA instead of the previous EPERM. One way to fix this in xfstests is to use listxattr(2) instead of getxattr(2), e.g., - getfattr -m $nsp -n $nsp.name2 $SCRATCH_MNT/$inode + getfattr -m $nsp.name2 $SCRATCH_MNT/$inode Another is to accept ENODATA as well as EPERM. Not sure which is preferable. Andreas