From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.wl.linuxfoundation.org ([198.145.29.98]:40576 "EHLO mail.wl.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725355AbeLTHtD (ORCPT ); Thu, 20 Dec 2018 02:49:03 -0500 Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EAC28283AD for ; Thu, 20 Dec 2018 07:49:02 +0000 (UTC) From: bugzilla-daemon@bugzilla.kernel.org To: linux-ext4@vger.kernel.org Subject: [Bug 201631] WARNING: CPU: 11 PID: 29593 at fs/ext4/inode.c:3927 .ext4_set_page_dirty+0x70/0xb0 Date: Thu, 20 Dec 2018 07:49:03 +0000 Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-ext4-owner@vger.kernel.org List-ID: https://bugzilla.kernel.org/show_bug.cgi?id=201631 --- Comment #28 from Jan Kara (jack@suse.cz) --- (In reply to Benjamin Herrenschmidt from comment #24) > Out of curiosity, how does this work in the context of pages that are GUPed > either by a driver or by KVM when using file backed guest memory ? > > GUP will not "see" the mkclean or attempt at making read only... That's a good question :) Well behaved GUP users use mmu notifiers as Aneesh wrote to "see" mkclean. Badly behaved GUP users (and there's quite a few of them) don't and that can result in kernel crashes, data loss, or checksum failures in storage stack. The latest discussion on this topic is here if you're interested: https://lwn.net/Articles/774411/ -- You are receiving this mail because: You are watching the assignee of the bug.