From patchwork Tue Mar 26 11:55:29 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wang Shilong X-Patchwork-Id: 2336181 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id E76423FC54 for ; Tue, 26 Mar 2013 11:55:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759415Ab3CZLzu (ORCPT ); Tue, 26 Mar 2013 07:55:50 -0400 Received: from mail-pb0-f45.google.com ([209.85.160.45]:42662 "EHLO mail-pb0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759379Ab3CZLzr (ORCPT ); Tue, 26 Mar 2013 07:55:47 -0400 Received: by mail-pb0-f45.google.com with SMTP id ro8so4736479pbb.4 for ; Tue, 26 Mar 2013 04:55:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=x-received:from:to:cc:subject:date:message-id:x-mailer:in-reply-to :references; bh=tdMjkrBehBR01zpo/OlsGikf5dPMad3E7/RkYo0M1u4=; b=IrV4IwCOMDLdOWc2+hzRJOEY648FD5bRO/sx9zmipYRqn4r3SQS35VUEZ7+fOc9RE/ +7uvr0iheoony9lEh9iNgJEfmrHuqLYuk2mLAr/tPOkWD9/Z2pWxE5k7/rgzQuRO+uQ/ o+GpcS501zVn6LwHLhR5GvD+KVu59D1LAT1zwsbBy7RCSHDALdD1kOB1b1yKfxsPwEwQ gd3s2nz+cwSkfspEM1MfsIeAI5gOUNwujN1HkHdfBywlEg6RJWBPhdTE3yoL2G/JayzD Tw6aB0Kn8aDwBvjnQ71XfQZLgWdvYU9UzY5rTMN+o/w6ssBMDL1bdresHEegeLGrlchf ceNA== X-Received: by 10.68.196.193 with SMTP id io1mr22766338pbc.196.1364298947297; Tue, 26 Mar 2013 04:55:47 -0700 (PDT) Received: from localhost.localdomain.localdomain ([223.65.184.172]) by mx.google.com with ESMTPS id fh1sm18974580pac.1.2013.03.26.04.55.44 (version=TLSv1 cipher=RC4-SHA bits=128/128); Tue, 26 Mar 2013 04:55:46 -0700 (PDT) From: Wang Shilong To: linux-btrfs@vger.kernel.org Cc: sensille@gmx.net, miaox@cn.fujitsu.com, wangshilong1991@gmail.com Subject: [PATCH 6/7] Btrfs: remove unnecessary spin_lock holding for find_qgroup_rb() Date: Tue, 26 Mar 2013 19:55:29 +0800 Message-Id: <1364298930-4507-6-git-send-email-wangshilong1991@gmail.com> X-Mailer: git-send-email 1.7.11.7 In-Reply-To: <1364298930-4507-1-git-send-email-wangshilong1991@gmail.com> References: <1364298930-4507-1-git-send-email-wangshilong1991@gmail.com> Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org From: Wang Shilong Since mutex has been used for quota operations, we don't have to hold spin_lock when calling find_qgroup_rb. Signed-off-by: Wang Shilong Reviewed-by: Miao Xie --- fs/btrfs/qgroup.c | 15 ++++++--------- 1 files changed, 6 insertions(+), 9 deletions(-) diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c index e3598fa..e123d5c 100644 --- a/fs/btrfs/qgroup.c +++ b/fs/btrfs/qgroup.c @@ -98,7 +98,10 @@ struct btrfs_qgroup_list { struct btrfs_qgroup *member; }; -/* must be called with qgroup_lock held */ +/* + * don't need to be held by spin_lock, because it has been protected by + * quota_lock + */ static struct btrfs_qgroup *find_qgroup_rb(struct btrfs_fs_info *fs_info, u64 qgroupid) { @@ -1041,15 +1044,12 @@ int btrfs_remove_qgroup(struct btrfs_trans_handle *trans, return -EINVAL; /* check if there are no relations to this qgroup */ - spin_lock(&fs_info->qgroup_lock); qgroup = find_qgroup_rb(fs_info, qgroupid); if (qgroup) { if (!list_empty(&qgroup->groups) || !list_empty(&qgroup->members)) { - spin_unlock(&fs_info->qgroup_lock); return -EBUSY; } } - spin_unlock(&fs_info->qgroup_lock); ret = del_qgroup_item(trans, quota_root, qgroupid); @@ -1081,22 +1081,19 @@ int btrfs_limit_qgroup(struct btrfs_trans_handle *trans, (unsigned long long)qgroupid); } - spin_lock(&fs_info->qgroup_lock); - qgroup = find_qgroup_rb(fs_info, qgroupid); if (!qgroup) { ret = -ENOENT; - goto unlock; + return ret; } + spin_lock(&fs_info->qgroup_lock); qgroup->lim_flags = limit->flags; qgroup->max_rfer = limit->max_rfer; qgroup->max_excl = limit->max_excl; qgroup->rsv_rfer = limit->rsv_rfer; qgroup->rsv_excl = limit->rsv_excl; -unlock: spin_unlock(&fs_info->qgroup_lock); - return ret; }