Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:34573 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751464Ab0LANOk (ORCPT ); Wed, 1 Dec 2010 08:14:40 -0500 Message-ID: <4CF64A34.7070100@redhat.com> Date: Wed, 01 Dec 2010 08:14:28 -0500 From: Rik van Riel To: Trond Myklebust CC: Linus Torvalds , Nick Bowler , Linux Kernel Mailing List , linux-nfs@vger.kernel.org Subject: Re: [PATCH 2/3] NFS: lock the readdir page while it is in use References: <1291175234-23824-1-git-send-email-Trond.Myklebust@netapp.com> <1291175234-23824-2-git-send-email-Trond.Myklebust@netapp.com> <1291175234-23824-3-git-send-email-Trond.Myklebust@netapp.com> <1291177753.7694.17.camel@heimdal.trondhjem.org> In-Reply-To: <1291177753.7694.17.camel@heimdal.trondhjem.org> Content-Type: text/plain; charset=UTF-8; format=flowed Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 On 11/30/2010 11:29 PM, Trond Myklebust wrote: > I'm not worried about other readdir calls invalidating the page. My > concern is rather about the VM memory reclaimers ejecting the page from > the page cache, and calling nfs_readdir_clear_array while we're > referencing the page. Wait, if nfs_readdir_clear_array can clear the page while somebody else has a refcount to it, what good is the refcount? Why is your .releasepage modifying the data on the page, instead of just the metadata in the struct page? -- All rights reversed