Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964950AbcCOPgI (ORCPT ); Tue, 15 Mar 2016 11:36:08 -0400 Received: from [198.137.202.9] ([198.137.202.9]:51145 "EHLO bombadil.infradead.org" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752186AbcCOPgF (ORCPT ); Tue, 15 Mar 2016 11:36:05 -0400 Date: Tue, 15 Mar 2016 08:35:15 -0700 From: Christoph Hellwig To: Richard Weinberger Cc: "Kirill A. Shutemov" , 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: <20160315153515.GA28522@infradead.org> 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/1.5.24 (2015-08-30) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 665 Lines: 16 On Tue, Mar 15, 2016 at 04:25:50PM +0100, Richard Weinberger wrote: > 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... FYI, XFS would blow up unless either ->write_begin or ->page_mkwrite were called before dirtying a page. We do an assert that the page has buffers as the first thing in writepage, and those are the only two places that should create buffers. So either no one is using CMA with XFS, or there is another weird interaction involved.