From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ot0-f200.google.com (mail-ot0-f200.google.com [74.125.82.200]) by kanga.kvack.org (Postfix) with ESMTP id 592416B025F for ; Mon, 27 Nov 2017 11:20:02 -0500 (EST) Received: by mail-ot0-f200.google.com with SMTP id u10so15940008otc.21 for ; Mon, 27 Nov 2017 08:20:02 -0800 (PST) Received: from mail-sor-f41.google.com (mail-sor-f41.google.com. [209.85.220.41]) by mx.google.com with SMTPS id u27sor8578617otc.169.2017.11.27.08.20.01 for (Google Transport Security); Mon, 27 Nov 2017 08:20:01 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <20171127161511.GE5977@quack2.suse.cz> References: <151068938905.7446.12333914805308312313.stgit@dwillia2-desk3.amr.corp.intel.com> <151068939985.7446.15684639617389154187.stgit@dwillia2-desk3.amr.corp.intel.com> <20171127161511.GE5977@quack2.suse.cz> From: Dan Williams Date: Mon, 27 Nov 2017 08:19:59 -0800 Message-ID: Subject: Re: [PATCH v2 2/4] mm: fail get_vaddr_frames() for filesystem-dax mappings Content-Type: text/plain; charset="UTF-8" Sender: owner-linux-mm@kvack.org List-ID: To: Jan Kara Cc: Andrew Morton , Joonyoung Shim , "linux-nvdimm@lists.01.org" , Seung-Woo Kim , "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" , Inki Dae , Linux MM , Kyungmin Park , Mel Gorman , Mauro Carvalho Chehab , Vlastimil Babka , "Linux-media@vger.kernel.org" On Mon, Nov 27, 2017 at 8:15 AM, Jan Kara wrote: > On Tue 14-11-17 11:56:39, Dan Williams wrote: >> Until there is a solution to the dma-to-dax vs truncate problem it is >> not safe to allow V4L2, Exynos, and other frame vector users to create >> long standing / irrevocable memory registrations against filesytem-dax >> vmas. >> >> Cc: Inki Dae >> Cc: Seung-Woo Kim >> Cc: Joonyoung Shim >> Cc: Kyungmin Park >> Cc: Mauro Carvalho Chehab >> Cc: linux-media@vger.kernel.org >> Cc: Jan Kara >> Cc: Mel Gorman >> Cc: Vlastimil Babka >> Cc: Andrew Morton >> Cc: >> Fixes: 3565fce3a659 ("mm, x86: get_user_pages() for dax mappings") >> Signed-off-by: Dan Williams > > Makes sense. I'd just note that in principle get_vaddr_frames() is no more > long-term than get_user_pages(). It is just so that all the users of > get_vaddr_frames() currently want a long-term reference. Maybe could you > add here also a comment that the vma_is_fsdax() check is there because all > users of this function want a long term page reference? With that you can > add: Ok, will do. > Reviewed-by: Jan Kara Thanks. -- 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