From patchwork Wed Jul 8 03:44:09 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhaolei X-Patchwork-Id: 6740261 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 0E9E59F380 for ; Wed, 8 Jul 2015 03:49:26 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 1B51B20784 for ; Wed, 8 Jul 2015 03:49:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0B5A920700 for ; Wed, 8 Jul 2015 03:49:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758060AbbGHDsG (ORCPT ); Tue, 7 Jul 2015 23:48:06 -0400 Received: from cn.fujitsu.com ([59.151.112.132]:33647 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1757861AbbGHDqm (ORCPT ); Tue, 7 Jul 2015 23:46:42 -0400 X-IronPort-AV: E=Sophos;i="5.13,665,1427731200"; d="scan'208";a="98204520" Received: from unknown (HELO edo.cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 08 Jul 2015 11:50:31 +0800 Received: from G08CNEXCHPEKD03.g08.fujitsu.local (localhost.localdomain [127.0.0.1]) by edo.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id t683iuF0024543 for ; Wed, 8 Jul 2015 11:44:56 +0800 Received: from localhost.localdomain (10.167.226.114) by G08CNEXCHPEKD03.g08.fujitsu.local (10.167.33.89) with Microsoft SMTP Server id 14.3.181.6; Wed, 8 Jul 2015 11:46:37 +0800 From: Zhaolei To: CC: Zhao Lei , Qu Wenruo Subject: [PATCH v3 4/4] btrfs: Fix data checksum error cause by replace with io-load. Date: Wed, 8 Jul 2015 11:44:09 +0800 Message-ID: <955d4a564a4f44b1a2d3485e21207530b66f75b9.1436326244.git.zhaolei@cn.fujitsu.com> X-Mailer: git-send-email 1.8.5.1 In-Reply-To: References: MIME-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Spam-Status: No, score=-7.7 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Zhao Lei xfstests btrfs/070 sometimes failed. In my test machine, its fail rate is about 30%. In another vm(vmware), its fail rate is about 50%. Reason: btrfs/070 do replace and defrag with fsstress simultaneously, after above operation, checksum error is found by scrub. Actually, it have no relationship with defrag operation, only replace with fsstress can trigger this bug. New data writen to target device have possibility rewrited by old data from source device by replace code in debug, to avoid above problem, we can set target block group to readonly in replace period, so new data requested by other operation will not write to same place with replace code. Before patch(4.1-rc3): 30% failed in 100 xfstests. After patch: 0% failed in 300 xfstests. It also happened in btrfs/071. Changelog v2->v3: 1: Fix a typo(caused in rebase) which make xfstests failed in btrfs/073 and btrfs/066. 2: Rebase on top of integration-4.2 3: Do full xfstests(generic and btrfs group with 10 mount options) Changelog v1->v2: 1: Update subject to reflect the problem being fixed. 2: Update description to say reason why set read-only can fix the problem. 3: Use a helper function to avoid duplicated code block for set chunk ro. All of above are suggested by: David Sterba Reported-by: Qu Wenruo Suggested-by: Qu Wenruo Signed-off-by: Qu Wenruo Signed-off-by: Zhao Lei --- fs/btrfs/scrub.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c index a882a34..3a49a43 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -3467,6 +3467,18 @@ int scrub_enumerate_chunks(struct scrub_ctx *sctx, if (!cache) goto skip; + /* + * we need call btrfs_inc_block_group_ro() with scrubs_paused, + * to avoid deadlock caused by: + * btrfs_inc_block_group_ro() + * -> btrfs_wait_for_commit() + * -> btrfs_commit_transaction() + * -> btrfs_scrub_pause() + */ + scrub_pause_on(fs_info); + btrfs_inc_block_group_ro(root, cache); + scrub_pause_off(fs_info); + dev_replace->cursor_right = found_key.offset + length; dev_replace->cursor_left = found_key.offset; dev_replace->item_needs_writeback = 1; @@ -3506,6 +3518,8 @@ int scrub_enumerate_chunks(struct scrub_ctx *sctx, scrub_pause_off(fs_info); + btrfs_dec_block_group_ro(root, cache); + btrfs_put_block_group(cache); if (ret) break;