From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Subject: Re: openg and path_to_handle Date: Wed, 6 Dec 2006 09:04:39 -0700 Message-ID: <20061206160439.GV3013@parisc-linux.org> References: <20061128055428.GA29891@infradead.org> <20061129090450.GA16296@infradead.org> <20061129122313.GG14315@parisc-linux.org> <20061129123913.GA15994@infradead.org> <4570ACD1.7060800@mcs.anl.gov> <4574BF52.6090600@mcs.anl.gov> <20061206094805.GB33919298@melbourne.sgi.com> <4576E783.7020402@mcs.anl.gov> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: David Chinner , Latchesar Ionkov , Christoph Hellwig , Gary Grider , linux-fsdevel@vger.kernel.org Return-path: Received: from palinux.external.hp.com ([192.25.206.14]:45910 "EHLO mail.parisc-linux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936301AbWLFQEk (ORCPT ); Wed, 6 Dec 2006 11:04:40 -0500 To: Rob Ross Content-Disposition: inline In-Reply-To: <4576E783.7020402@mcs.anl.gov> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Wed, Dec 06, 2006 at 09:53:39AM -0600, Rob Ross wrote: > David Chinner wrote: > >Does anyone here know about the XFS libhandle API? This has been > >around for years and it does _exactly_ what these proposed syscalls > >are supposed to do (and more). > > Thanks for pointing these out Dave. These are indeed along the same > lines as the openg()/openfh() approach. > > One difference is that they appear to perform permission checking on the > open_by_handle(), which means that the entire path needs to be encoded > in the handle, and makes it difficult to eliminate the path traversal > overhead on N open_by_handle() operations. Another (and highly important) difference is that usage is restricted to root: xfs_open_by_handle(...) ... if (!capable(CAP_SYS_ADMIN)) return -XFS_ERROR(EPERM);