Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756382AbcCOPrO (ORCPT ); Tue, 15 Mar 2016 11:47:14 -0400 Received: from mail-wm0-f51.google.com ([74.125.82.51]:37019 "EHLO mail-wm0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755547AbcCOPrL (ORCPT ); Tue, 15 Mar 2016 11:47:11 -0400 Date: Tue, 15 Mar 2016 18:47:08 +0300 From: "Kirill A. Shutemov" To: Richard Weinberger Cc: linux-fsdevel , "linux-mtd@lists.infradead.org" , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , Boris Brezillon , Maxime Ripard , David Gstir , Dave Chinner , Artem Bityutskiy , "Kirill A. Shutemov" , Alexander Kaplan Subject: Re: Page migration issue with UBIFS Message-ID: <20160315154708.GC16462@node.shutemov.name> References: <56E8192B.5030008@nod.at> <20160315151727.GA16462@node.shutemov.name> <56E8297E.80708@nod.at> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <56E8297E.80708@nod.at> User-Agent: Mutt/1.5.23.1 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1198 Lines: 35 On Tue, Mar 15, 2016 at 04:25:50PM +0100, Richard Weinberger wrote: > Kirill, > > Am 15.03.2016 um 16:17 schrieb Kirill A. Shutemov: > > On Tue, Mar 15, 2016 at 03:16:11PM +0100, Richard Weinberger wrote: > >> Hi! > >> > >> We're facing this issue from 2014 on UBIFS: > >> http://www.spinics.net/lists/linux-fsdevel/msg79941.html > >> > >> So sum up: > >> UBIFS does not allow pages directly marked as dirty. It want's everyone to do it via UBIFS's > >> ->wirte_end() and ->page_mkwirte() functions. > >> This assumption *seems* to be violated by CMA which migrates pages. > > > > I don't thing the CMA/migration is the root cause. > > > > How did we end up with writable and dirty pte, but not having > > ->page_mkwrite() called for the page? > > > > Or if ->page_mkwrite() was called, why the page is not dirty? > > Thanks for your quick response! > > I also don't think that the root cause is CMA or migration but it seems > to be the messenger. > > Can you confirm that UBIFS's assumptions are valid? > I'm trying to rule out possible issues and hunt down the root cause... The assumption looks reasonable for me, but I am not confident enough to "confirm" it. -- Kirill A. Shutemov