Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764652AbXJOLsH (ORCPT ); Mon, 15 Oct 2007 07:48:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759166AbXJOLrz (ORCPT ); Mon, 15 Oct 2007 07:47:55 -0400 Received: from nz-out-0506.google.com ([64.233.162.225]:41468 "EHLO nz-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757050AbXJOLrx (ORCPT ); Mon, 15 Oct 2007 07:47:53 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:sender:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references:x-google-sender-auth; b=JLNBFDqHTEUMXYQwTrI1SukuiDzNze2Yu11VVk0w8d0VADdKpxcJa6D2fkQwDE2E3SWUX5xD0OCjWkgMd2wg72TMSXQpp2zw7nWhr10PVtQQMI78erBiv0WkB/T/al2AuhP2nQ6f9JIA+aSMvKxfnZ68Z054n1m5INyOEafBgVI= Message-ID: <84144f020710150447o94b1babo8b6e6a647828465f@mail.gmail.com> Date: Mon, 15 Oct 2007 14:47:52 +0300 From: "Pekka Enberg" To: "Erez Zadok" Subject: Re: msync(2) bug(?), returns AOP_WRITEPAGE_ACTIVATE to userland Cc: "Hugh Dickins" , "Ryan Finnie" , "Andrew Morton" , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, cjwatson@ubuntu.com, linux-mm@kvack.org In-Reply-To: <200710142232.l9EMW8kK029572@agora.fsl.cs.sunysb.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <200710142232.l9EMW8kK029572@agora.fsl.cs.sunysb.edu> X-Google-Sender-Auth: b53b24ca58b034e7 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1063 Lines: 24 Hi, On 10/15/07, Erez Zadok wrote: > Pekka, with a small change to your patch (to handle time-based cache > coherency), your patch worked well and passed all my tests. Thanks. > > So now I wonder if we still need the patch to prevent AOP_WRITEPAGE_ACTIVATE > from being returned to userland. I guess we still need it, b/c even with > your patch, generic_writepages() can return AOP_WRITEPAGE_ACTIVATE back to > the VFS and we need to ensure that doesn't "leak" outside the kernel. I wonder whether _not setting_ BDI_CAP_NO_WRITEBACK implies that ->writepage() will never return AOP_WRITEPAGE_ACTIVATE for !wbc->for_reclaim case which would explain why we haven't hit this bug before. Hugh, Andrew? And btw, I think we need to fix ecryptfs too. Pekka - 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/