Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751769Ab0HUJcg (ORCPT ); Sat, 21 Aug 2010 05:32:36 -0400 Received: from e23smtp01.au.ibm.com ([202.81.31.143]:37937 "EHLO e23smtp01.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751613Ab0HUJce (ORCPT ); Sat, 21 Aug 2010 05:32:34 -0400 From: "Aneesh Kumar K. V" To: Andreas Dilger , Neil Brown Cc: Al Viro , Christoph Hellwig , "adilger\@sun.com" , "corbet\@lwn.net" , "npiggin\@kernel.dk" , "hooanon05\@yahoo.co.jp" , "bfields\@fieldses.org" , "miklos\@szeredi.hu" , "linux-fsdevel\@vger.kernel.org" , "sfrench\@us.ibm.com" , "philippe.deniel\@CEA.FR" , "linux-kernel\@vger.kernel.org" Subject: Re: [PATCH -V18 04/13] vfs: Allow handle based open on symlinks In-Reply-To: <17761610-AFA9-4BB5-AF62-CD54D67F5C79@oracle.com> References: <1282269097-26166-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1282269097-26166-5-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <20100820083057.GA10039@infradead.org> <20100820195303.20b17210@notabene> <20100820115135.GQ31363@ZenIV.linux.org.uk> <20100821100900.4b15fe08@notabene> <17761610-AFA9-4BB5-AF62-CD54D67F5C79@oracle.com> User-Agent: Notmuch/0.3.1-58-g6607fd6 (http://notmuchmail.org) Emacs/24.0.50.1 (i686-pc-linux-gnu) Date: Sat, 21 Aug 2010 15:02:14 +0530 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1292 Lines: 34 On Sat, 21 Aug 2010 01:13:52 -0600, Andreas Dilger wrote: > On 2010-08-20, at 18:09, Neil Brown wrote: > > How about a new AT flag: AT_FILE_HANDLE > > > > Meaning is that the 'dirfd' is used only to identify a filesystem (vfsmnt) and > > the 'name' pointer actually points to a filehandle fragment interpreted in > > that filesystem. > > > > One problem is that there is no way to pass the length... > > Options: > > fragment is at most 64 bytes nul padded at the end > > fragment is hex encoded and nul terminated > > ?? > > > > I think I prefer the hex encoding, but I'm hoping someone else has a better > > idea. > > That makes it ugly for the kernel to stringify and parse the file handles. > > How about for AT_FILE_HANDLE THE FIRST __u32 (maybe with an extra > __u32 for alignment) is the length and the rest of the binary file > handle follows this? In fact, doesn't the handle itself already > encode the length in the header? struct file_handle already include length -aneesh -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/