From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Brown Subject: Re: [EXT4 set 4][PATCH 1/5] i_version:64 bit inode version Date: Wed, 11 Jul 2007 15:05:27 +1000 Message-ID: <18068.25879.745638.343290@notabene.brown> References: <1183275424.4010.126.camel@localhost.localdomain> <20070710163038.ceb2ae94.akpm@linux-foundation.org> <1184105380.3759.65.camel@localhost.localdomain> <20070710182237.e2f88bf3.akpm@linux-foundation.org> <18068.19667.942363.686858@notabene.brown> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: Andrew Morton , linux-fsdevel@vger.kernel.org, nfsv4@linux-nfs.org, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org To: cmm@us.ibm.com Return-path: In-Reply-To: message from Neil Brown on Wednesday July 11 Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org It just occurred to me: If i_version is 64bit, then knfsd would need to be careful when reading it on a 32bit host. What are the locking rules? Presumably it is only updated under i_mutex protection, but having to get i_mutex to read it would seem a little heavy handed. Should it use a seqlock like i_size? Could we use the same seqlock that i_size uses, or would we need a separate one? NeilBrown