From patchwork Fri Jan 30 09:20:54 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qu Wenruo X-Patchwork-Id: 5748041 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 1DF339F358 for ; Fri, 30 Jan 2015 09:23:34 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 6445A20160 for ; Fri, 30 Jan 2015 09:23:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7F42A2013A for ; Fri, 30 Jan 2015 09:23:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760194AbbA3JXS (ORCPT ); Fri, 30 Jan 2015 04:23:18 -0500 Received: from cn.fujitsu.com ([59.151.112.132]:29041 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1760101AbbA3JXO (ORCPT ); Fri, 30 Jan 2015 04:23:14 -0500 X-IronPort-AV: E=Sophos;i="5.04,848,1406563200"; d="scan'208";a="56879850" Received: from unknown (HELO edo.cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 30 Jan 2015 17:19:33 +0800 Received: from G08CNEXCHPEKD02.g08.fujitsu.local (localhost.localdomain [127.0.0.1]) by edo.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id t0U9MMnt028867 for ; Fri, 30 Jan 2015 17:22:22 +0800 Received: from localhost.localdomain (10.167.226.33) by G08CNEXCHPEKD02.g08.fujitsu.local (10.167.33.89) with Microsoft SMTP Server (TLS) id 14.3.181.6; Fri, 30 Jan 2015 17:23:04 +0800 From: Qu Wenruo To: Subject: [PATCH v5 9/9] btrfs: Use sb_want_write() to protect sysfs feature change. Date: Fri, 30 Jan 2015 17:20:54 +0800 Message-ID: <1422609654-19519-10-git-send-email-quwenruo@cn.fujitsu.com> X-Mailer: git-send-email 2.2.2 In-Reply-To: <1422609654-19519-1-git-send-email-quwenruo@cn.fujitsu.com> References: <1422609654-19519-1-git-send-email-quwenruo@cn.fujitsu.com> MIME-Version: 1.0 X-Originating-IP: [10.167.226.33] Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_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 Just like label change, use sb_want_write() to do a correct protection. Signed-off-by: Qu Wenruo --- v4: Newly introduced. v5: Change to sb_want_write(). --- fs/btrfs/sysfs.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index 3218245..64f876e 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -154,9 +154,15 @@ static ssize_t btrfs_feature_attr_store(struct kobject *kobj, btrfs_info(fs_info, "%s %s feature flag", val ? "Setting" : "Clearing", fa->kobj_attr.attr.name); + ret = sb_want_write(fs_info->sb); + if (ret) + return ret; + trans = btrfs_start_transaction(fs_info->fs_root, 0); - if (IS_ERR(trans)) - return PTR_ERR(trans); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto out; + } spin_lock(&fs_info->super_lock); features = get_features(fs_info, fa->feature_set); @@ -168,10 +174,12 @@ static ssize_t btrfs_feature_attr_store(struct kobject *kobj, spin_unlock(&fs_info->super_lock); ret = btrfs_commit_transaction(trans, fs_info->fs_root); - if (ret) - return ret; - return count; +out: + sb_drop_write(fs_info->sb); + if (!ret) + return count; + return ret; } static umode_t btrfs_feature_visible(struct kobject *kobj,