From patchwork Mon Aug 17 10:44:45 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhaolei X-Patchwork-Id: 7024331 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 089C79F373 for ; Mon, 17 Aug 2015 10:46:33 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 06EFD20553 for ; Mon, 17 Aug 2015 10:46:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E3BBC20582 for ; Mon, 17 Aug 2015 10:46:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753271AbbHQKq0 (ORCPT ); Mon, 17 Aug 2015 06:46:26 -0400 Received: from cn.fujitsu.com ([59.151.112.132]:52735 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1750937AbbHQKqZ (ORCPT ); Mon, 17 Aug 2015 06:46:25 -0400 X-IronPort-AV: E=Sophos;i="5.15,520,1432569600"; d="scan'208";a="99717868" Received: from unknown (HELO edo.cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 17 Aug 2015 18:49:40 +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 t7HAkKX2019731 for ; Mon, 17 Aug 2015 18:46:20 +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; Mon, 17 Aug 2015 18:46:22 +0800 From: Zhao Lei To: CC: Zhao Lei Subject: [PATCH 1/2] btrfs: Remove useless condition in start_log_trans() Date: Mon, 17 Aug 2015 18:44:45 +0800 Message-ID: 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=-7.5 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 Dan Carpenter reported a smatch warning for start_log_trans(): fs/btrfs/tree-log.c:178 start_log_trans() warn: we tested 'root->log_root' before and it was 'false' fs/btrfs/tree-log.c 147 if (root->log_root) { We test "root->log_root" here. ... Reason: Condition of: fs/btrfs/tree-log.c:178: if (!root->log_root) { is not necessary after commit: 7237f1833 It caused a smatch warning, and no functionally error. Fix: Deleting above condition will make smatch shut up, but a better way is to do cleanup for start_log_trans() to remove duplicated code and make code more readable. Reported-by: Dan Carpenter Signed-off-by: Zhao Lei --- fs/btrfs/tree-log.c | 43 +++++++++++++++++-------------------------- 1 file changed, 17 insertions(+), 26 deletions(-) diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index 9c45431..66a8a58 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -140,55 +140,46 @@ static int start_log_trans(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_log_ctx *ctx) { - int index; - int ret; + int ret = 0; mutex_lock(&root->log_mutex); + if (root->log_root) { if (btrfs_need_log_full_commit(root->fs_info, trans)) { ret = -EAGAIN; goto out; } + if (!root->log_start_pid) { - root->log_start_pid = current->pid; clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state); + root->log_start_pid = current->pid; } else if (root->log_start_pid != current->pid) { set_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state); } + } else { + mutex_lock(&root->fs_info->tree_log_mutex); + if (!root->fs_info->log_root_tree) + ret = btrfs_init_log_root_tree(trans, root->fs_info); + mutex_unlock(&root->fs_info->tree_log_mutex); + if (ret) + goto out; - atomic_inc(&root->log_batch); - atomic_inc(&root->log_writers); - if (ctx) { - index = root->log_transid % 2; - list_add_tail(&ctx->list, &root->log_ctxs[index]); - ctx->log_transid = root->log_transid; - } - mutex_unlock(&root->log_mutex); - return 0; - } - - ret = 0; - mutex_lock(&root->fs_info->tree_log_mutex); - if (!root->fs_info->log_root_tree) - ret = btrfs_init_log_root_tree(trans, root->fs_info); - mutex_unlock(&root->fs_info->tree_log_mutex); - if (ret) - goto out; - - if (!root->log_root) { ret = btrfs_add_log_tree(trans, root); if (ret) goto out; + + clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state); + root->log_start_pid = current->pid; } - clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state); - root->log_start_pid = current->pid; + atomic_inc(&root->log_batch); atomic_inc(&root->log_writers); if (ctx) { - index = root->log_transid % 2; + int index = root->log_transid % 2; list_add_tail(&ctx->list, &root->log_ctxs[index]); ctx->log_transid = root->log_transid; } + out: mutex_unlock(&root->log_mutex); return ret;