From: Bernd Schubert Subject: Re: [PATCH 0/2] 32/64 bit llseek hashes (v3) Date: Tue, 30 Aug 2011 23:59:23 +0200 Message-ID: <4E5D5D3B.7010402@fastmail.fm> References: <20110816115404.1810393.47239.stgit@localhost.localdomain> <20110823215608.GH25350@fieldses.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Cc: Bernd Schubert , linux-nfs@vger.kernel.org, linux-ext4@vger.kernel.org, tytso@mit.edu, hch@infradead.org, adilger@whamcloud.com, yong.fan@whamcloud.com, linux-fsdevel@vger.kernel.org To: "J. Bruce Fields" Return-path: Received: from out3.smtp.messagingengine.com ([66.111.4.27]:36033 "EHLO out3.smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751058Ab1H3V7Z (ORCPT ); Tue, 30 Aug 2011 17:59:25 -0400 In-Reply-To: <20110823215608.GH25350@fieldses.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: On 08/23/2011 11:56 PM, J. Bruce Fields wrote: > On Tue, Aug 16, 2011 at 01:54:04PM +0200, Bernd Schubert wrote: >> With the ext3/ext4 directory index implementation hashes are used to specify >> offsets for llseek(). For compatibility with NFSv2 and 32-bit user space >> on 64-bit systems (kernel space) ext3/ext4 currently only return 32-bit >> hashes and therefore the probability of hash collisions for larger directories >> is rather high. As recently reported on the NFS mailing list that theoretical >> problem also happens on real systems: >> http://comments.gmane.org/gmane.linux.nfs/40863 >> >> The following series adds two new f_mode flags to tell ext4 >> to use 32-bit or 64-bit hash values for llseek() calls. >> These flags can then used by network file systems, such as NFS, to >> request 32-bit or 64-bit offsets (hashes). >> >> Version 3: >> - remove patch "RFC: Remove check for a 32-bit cookie in nfsd4_readdir()", >> I think Bruce wanted to take it seperately as bug fix. It should be applied >> before applying the remaining NFS patches, as without it NFSv4 will always >> fail with the new 64-bit ext4 seek hashes. > > Yes, applied to my for-3.2 branch at > git://linux-nfs.org/~bfields/linux.git. > > For the NFS patches: > > Acked-by: J. Bruce Fields > > OK by me if they go in through ext4 tree, or however's most convenient. Great, thanks! Cheers, Bernd