From patchwork Thu Aug 6 13:56:58 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhaolei X-Patchwork-Id: 6959181 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 592F59F358 for ; Thu, 6 Aug 2015 13:58:44 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 2CE59206FD for ; Thu, 6 Aug 2015 13:58:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 129D4206FB for ; Thu, 6 Aug 2015 13:58:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753951AbbHFN6h (ORCPT ); Thu, 6 Aug 2015 09:58:37 -0400 Received: from cn.fujitsu.com ([59.151.112.132]:18104 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1753601AbbHFN6g (ORCPT ); Thu, 6 Aug 2015 09:58:36 -0400 X-IronPort-AV: E=Sophos;i="5.15,520,1432569600"; d="scan'208";a="99346725" Received: from unknown (HELO edo.cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 06 Aug 2015 22:02:01 +0800 Received: from G08CNEXCHPEKD01.g08.fujitsu.local (localhost.localdomain [127.0.0.1]) by edo.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id t76DudNU020380 for ; Thu, 6 Aug 2015 21:56:39 +0800 Received: from localhost.localdomain (10.167.226.114) by G08CNEXCHPEKD01.g08.fujitsu.local (10.167.33.89) with Microsoft SMTP Server id 14.3.181.6; Thu, 6 Aug 2015 21:58:33 +0800 From: Zhao Lei To: CC: Zhao Lei Subject: [PATCH] btrfs: abort transaction on btrfs_reloc_cow_block() Date: Thu, 6 Aug 2015 21:56:58 +0800 Message-ID: <112f5da071c0d3446fedf7c7828c78ae586e11fb.1438869404.git.zhaolei@cn.fujitsu.com> X-Mailer: git-send-email 1.8.5.1 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=-7.0 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 When btrfs_reloc_cow_block() failed in __btrfs_cow_block(), current code just return a err-value to caller, but leave new_created extent buffer exist and locked. Then subsequent code (in relocate) try to lock above eb again, and caused deadlock without any dmesg. (eb lock use wait_event(), so no lockdep message) It is hard to do recover work in __btrfs_cow_block() at this error point, but we can abort transaction to avoid deadlock and operate on unstable state.a It also helps developer to find wrong place quickly. (better than a frozen fs without any dmesg before patch) Signed-off-by: Zhao Lei --- fs/btrfs/ctree.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 54114b4..5f745ea 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -1159,8 +1159,10 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, if (test_bit(BTRFS_ROOT_REF_COWS, &root->state)) { ret = btrfs_reloc_cow_block(trans, root, buf, cow); - if (ret) + if (ret) { + btrfs_abort_transaction(trans, root, ret); return ret; + } } if (buf == root->node) {