Return-Path: Received: from bombadil.infradead.org ([18.85.46.34]:45077 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750852Ab0LUP0j (ORCPT ); Tue, 21 Dec 2010 10:26:39 -0500 Date: Tue, 21 Dec 2010 10:26:39 -0500 From: Christoph Hellwig To: Fred Isaman Cc: linux-nfs@vger.kernel.org, Trond Myklebust Subject: Re: [PATCH 04/14] pnfs: wave 2: change layout state seqlock to a spinlock Message-ID: <20101221152639.GC30248@infradead.org> References: <1292898046-7336-1-git-send-email-iisaman@netapp.com> <1292898046-7336-5-git-send-email-iisaman@netapp.com> Content-Type: text/plain; charset=us-ascii In-Reply-To: <1292898046-7336-5-git-send-email-iisaman@netapp.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 On Mon, Dec 20, 2010 at 09:20:36PM -0500, Fred Isaman wrote: > This prepares for future changes, where the layout state needs > to change atomically with several other variables. In particular, > it will need to know if lo->segs is empty, as we test that instead > of manipulating the NFS_LAYOUT_STATEID_SET bit. Moreover, the > layoutstateid is not really a read-mostly structure, as it is > written almost as often as it is read. It also renames a couple of functions.