From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C595EC43381 for ; Sat, 16 Feb 2019 02:08:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 93020222A1 for ; Sat, 16 Feb 2019 02:08:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=intel-com.20150623.gappssmtp.com header.i=@intel-com.20150623.gappssmtp.com header.b="NZAi8qeq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733204AbfBPCI3 (ORCPT ); Fri, 15 Feb 2019 21:08:29 -0500 Received: from mail-ot1-f66.google.com ([209.85.210.66]:41812 "EHLO mail-ot1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726473AbfBPCI2 (ORCPT ); Fri, 15 Feb 2019 21:08:28 -0500 Received: by mail-ot1-f66.google.com with SMTP id t7so3427973otk.8 for ; Fri, 15 Feb 2019 18:08:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=intel-com.20150623.gappssmtp.com; s=20150623; h=mime-version:from:date:message-id:subject:to:cc; bh=E8MQdVUTQEeEu3nqjpLgUdTpwxg637m/uFGbvQJuSWY=; b=NZAi8qeqKa4RmPPWbQVLGsqH4HcPbbo4moBaDR6y/8pPawWONe13ZuvYXTo5GAHWT+ 2SEhnciu5Nxtikh1o/YLTFaui0l1W7N0BaCqWNMvEK+gdODVygA3nZm22lFn8HMNXNx3 STYAiZbSyO1Ox1c4sb4rzFQxdwtm2u3uBEq0ew6AthQ6ApS6/Ujbyv7ulFPS09nFNLPt nzZu6SouDanwDSRF3oecaNGJdqKJ0PXHwkLOud3BY85NPhN/hLR4Z7zDbDgypEricMVC R2gNUbkDzNKG0rv1ODmTwk7QgP5+T9W89SDM8e+uNq9jEGvZT3Vn5g9OrZ7T5Z/X0/o1 iT5w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to:cc; bh=E8MQdVUTQEeEu3nqjpLgUdTpwxg637m/uFGbvQJuSWY=; b=RgDr+v4NqFAXbbzfEA7b30Ob6bAonb4k1zbD/qvfVZkACumKkxOomf7YiGD+9Wed69 YpbtwyxgOUWoDCRsRmhyjp0kjOiz/hMbJuNKgaodgHSXz84e7+9qWehjxJXUzXMb7kyw 7zbiWvQMS2uOnk+1Fna8qPfMXmamhw+t7l0vNgf8W+v5wkFsYyTs6AEHYEn66cwA1qe5 XvHQHPdP2YCLqQr+OzAW9EkiBR5GwyKyeEEObqBPtbg824483QMO7OlT8jbL7ng+gKiZ skaEHqsYhJa3iyzhPTK/jmRSmq1v0kRma8rpaOf4B5BNObUETWD7/flUm+JvilSbHpYs Ksww== X-Gm-Message-State: AHQUAuYWbjJW2wfH7f/N5k3+ev/0r/hCORcduzT8YYnnx0BkZkqWOG6Y +c9IyKEMJ9SiBq+zpDqTRW6sDRc0QpH+GPM827CtYQ== X-Google-Smtp-Source: AHgI3IYiHFdoZ4/8rxjRC06U3FUw/zyaCagWPgW++88v+Zd3W6gFP6Xc57iHPsqgcS/aRz9zESCBYGPq1WDZ2Jsdub4= X-Received: by 2002:a9d:7a87:: with SMTP id l7mr274118otn.98.1550282907624; Fri, 15 Feb 2019 18:08:27 -0800 (PST) MIME-Version: 1.0 From: Dan Williams Date: Fri, 15 Feb 2019 18:08:15 -0800 Message-ID: Subject: find_get_entries_tag regression bisected To: Matthew Wilcox Cc: linux-nvdimm , linux-fsdevel , Linux Kernel Mailing List , "Balcer, Piotr" Content-Type: text/plain; charset="UTF-8" Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Hi Willy, Piotr reports the following crash can be triggered on latest mainline: EXT4-fs (pmem5): recovery complete EXT4-fs (pmem5): mounted filesystem with ordered data mode. Opts: dax ------------[ cut here ]------------ kernel BUG at mm/pgtable-generic.c:127! invalid opcode: 0000 [#1] SMP PTI CPU: 28 PID: 1193 Comm: a.out Tainted: G W OE 4.19.0-rc5+ #2907 [..] RIP: 0010:pmdp_huge_clear_flush+0x1e/0x80 [..] Call Trace: dax_writeback_mapping_range+0x473/0x8a0 ? print_shortest_lock_dependencies+0x40/0x40 ? jbd2_journal_stop+0xef/0x470 ? ext4_fill_super+0x3071/0x3110 ? __lock_is_held+0x4f/0x90 ? __lock_is_held+0x4f/0x90 ext4_dax_writepages+0xed/0x2f0 do_writepages+0x41/0xe0 __filemap_fdatawrite_range+0xbe/0xf0 file_write_and_wait_range+0x4c/0xa0 ext4_sync_file+0xa6/0x4f0 I bisected this regression to commit c1901cd33cf4 "page cache: Convert find_get_entries_tag to XArray". I suspect another case of pte vs pmd confusion. Below is the small reproducer from Piotr, it triggers in a qemu environment with emulated pmem, but only with ext4 that I can see, but I did not dig too deep. Let me know if anything jumps out to you. I'll otherwise take a deeper look in the coming days. #include #include #include #include #include #include #define MB (1ULL << 20) int main(int argc, char *argv[]) { int ret; int fd; off_t size = 2 * MB; char *path = argv[1]; fd = open(path, O_RDWR | O_CREAT | O_EXCL, 0666); assert(fd > 0); ret = ftruncate(fd, size); assert(ret == 0); char *addr = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); assert(addr != MAP_FAILED); memset((char*)addr, '0', 1); ret = msync(addr + 4096, 1, MS_SYNC); assert(ret == 0); close(fd); return 0; }