From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.wl.linuxfoundation.org ([198.145.29.98]:35762 "EHLO mail.wl.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726170AbeLKLVS (ORCPT ); Tue, 11 Dec 2018 06:21:18 -0500 Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 39D272A472 for ; Tue, 11 Dec 2018 11:21:17 +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: Tue, 11 Dec 2018 11:21:17 +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 Jan Kara (jack@suse.cz) changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |benh@kernel.crashing.org, | |jack@suse.cz, | |michael@ellerman.id.au --- Comment #8 from Jan Kara (jack@suse.cz) --- The lockups and ext4 warnings are likely a different thing. So please report the lockup to linux-fsdevel@vger.kernel.org and also CC Al Viro on it. The WARN_ON we hit in ext4 is likely: WARN_ON_ONCE(!PageLocked(page) && !PageDirty(page)); because we don't expect page cache page to be marked dirty when unmapping it from page tables. It could be a powerpc specific race in handling of page table entry (PTE) flags as I don't see how PTE could be marked dirty without a page being already dirty. Seeing you hit this already twice on 4.20-rc's and never on 4.19.x, it could be some recent powerpc change that is triggering this. I've skimmed through powerpc changelogs and didn't find anything obviously matching but there were quite some mm changes pulled in this merge window. Powerpc guys, any idea how could _PAGE_DIRTY PTE bit get spuriously set? Normally, we should clear the _PAGE_DIRTY bit in page_mkclean() together with write-protecting the PTE and we are marking the page dirty whenever writeable PTE is created... So clean pagecache page with _PAGE_DIRTY in PTE is an invalid combination. -- You are receiving this mail because: You are watching the assignee of the bug.