From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f44.google.com (mail-wm0-f44.google.com [74.125.82.44]) by kanga.kvack.org (Postfix) with ESMTP id 3D4076B025E for ; Tue, 15 Mar 2016 19:18:55 -0400 (EDT) Received: by mail-wm0-f44.google.com with SMTP id p65so48337928wmp.0 for ; Tue, 15 Mar 2016 16:18:55 -0700 (PDT) Received: from radon.swed.at (a.ns.miles-group.at. [95.130.255.143]) by mx.google.com with ESMTPS id vl10si568711wjc.75.2016.03.15.16.18.53 for (version=TLS1 cipher=AES128-SHA bits=128/128); Tue, 15 Mar 2016 16:18:54 -0700 (PDT) Subject: Re: Page migration issue with UBIFS References: <56E8192B.5030008@nod.at> <20160315151727.GA16462@node.shutemov.name> <56E82B18.9040807@nod.at> <20160315153744.GB28522@infradead.org> From: Richard Weinberger Message-ID: <56E8985A.1020509@nod.at> Date: Wed, 16 Mar 2016 00:18:50 +0100 MIME-Version: 1.0 In-Reply-To: <20160315153744.GB28522@infradead.org> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Hellwig 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 Am 15.03.2016 um 16:37 schrieb Christoph Hellwig: > On Tue, Mar 15, 2016 at 04:32:40PM +0100, Richard Weinberger wrote: >>> Or if ->page_mkwrite() was called, why the page is not dirty? >> >> BTW: UBIFS does not implement ->migratepage(), could this be a problem? > > This might be the reason. I can't reall make sense of > buffer_migrate_page, but it seems to migrate buffer_head state to > the new page. > > I'd love to know why CMA even tries to migrate pages that don't have a > ->migratepage method, this seems incredibly dangerous to me. FYI, with a dummy ->migratepage() which returns only -EINVAL UBIFS does no longer explode upon page migration. Tomorrow I'll do more tests to make sure. Thanks, //richard -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org