Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754745AbXJHWub (ORCPT ); Mon, 8 Oct 2007 18:50:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752034AbXJHWuW (ORCPT ); Mon, 8 Oct 2007 18:50:22 -0400 Received: from fk-out-0910.google.com ([209.85.128.184]:30034 "EHLO fk-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751920AbXJHWuV (ORCPT ); Mon, 8 Oct 2007 18:50:21 -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=uneTD74F1kzYMdN0YaFILJSMUNDRMc/0zwIBV+VAaMQVqmiOS5dwBkd/Ie0aQBrWrko/kvwLCuDe+WCjQgmXYdCC8DKlLwCZjvdYt4HuR5rh+bMNMGsBA9sO5eL2AjR/RhtEatBiHJ8gjSbK39xRx5ulAJpVbTIQrQZmDSR906c= Message-ID: <3d0408630710081550k430f50c1nae5097776358f1a0@mail.gmail.com> Date: Tue, 9 Oct 2007 06:50:17 +0800 From: "Yan Zheng" To: "Hugh Dickins" Subject: Re: [PATCH]fix VM_CAN_NONLINEAR check in sys_remap_file_pages Cc: "Nick Piggin" , "Miklos Szeredi" , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <3d0408630710080445j4dea115emdfe29aac26814536@mail.gmail.com> X-Google-Sender-Auth: 099984a27680e61d Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1391 Lines: 26 2007/10/8, Hugh Dickins : > On Mon, 8 Oct 2007, Yan Zheng wrote: > > > > The test for VM_CAN_NONLINEAR always fails > Good catch indeed. Though I was puzzled how we do nonlinear at all, > until I realized it's "The test for not VM_CAN_NONLINEAR always fails". > It's not as serious as it appears, since code further down has been > added more recently to simulate nonlinear on non-RAM-backed filesystems, > instead of going the real nonlinear way; so most filesystems are now not > required to do what VM_CAN_NONLINEAR was put in to ensure they could do. > I'm confused as to where that leaves us: is this actually a fix that > needs to go into 2.6.23? or will it suddenly disable a system call > which has been silently working fine on various filesystems which did > not add VM_CAN_NONLINEAR? could we just rip out VM_CAN_NONLINEAR? > I hope Nick or Miklos is clearer on what the risks are. > (Apologies for all the "not"s and "non"s here, I'm embarrassed > after just criticizing Ingo's SCHED_NO_NO_OMIT_FRAME_POINTER!) > Hugh Yes, I mean "The test for not VM_CAN_NONLINEAR always fails". please forgive my poor English. - 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/