From patchwork Mon Aug 31 08:54:34 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qu Wenruo X-Patchwork-Id: 7109341 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id C1E7BBEEC1 for ; Wed, 2 Sep 2015 07:52:43 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id E8D7820631 for ; Wed, 2 Sep 2015 07:52:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E94A320632 for ; Wed, 2 Sep 2015 07:52:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753138AbbIBHwj (ORCPT ); Wed, 2 Sep 2015 03:52:39 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:18969 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751772AbbIBHvQ (ORCPT ); Wed, 2 Sep 2015 03:51:16 -0400 Received: from unknown (HELO tang.cn.fujitsu.com) ([10.167.250.3]) by song.cn.fujitsu.com with ESMTP; 31 Aug 2015 16:55:40 +0800 Received: from localhost.localdomain (tang.cn.fujitsu.com [127.0.0.1]) by tang.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id t7V8udBx031126 for ; Mon, 31 Aug 2015 16:56:46 +0800 From: Qu Wenruo To: linux-btrfs@vger.kernel.org Subject: [PATCH RFC 03/14] btrfs: qgroup: Introduce new function to search most left reserve range Date: Mon, 31 Aug 2015 16:54:34 +0800 Message-Id: <1441011286-23733-4-git-send-email-quwenruo@cn.fujitsu.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1441011286-23733-1-git-send-email-quwenruo@cn.fujitsu.com> References: <1441011286-23733-1-git-send-email-quwenruo@cn.fujitsu.com> 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 Introduce the new function to search the most left reserve range in a reserve map. It provides the basis for later reserve map implement. Signed-off-by: Qu Wenruo --- fs/btrfs/qgroup.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c index 2e9a93f..e19fe6a 100644 --- a/fs/btrfs/qgroup.c +++ b/fs/btrfs/qgroup.c @@ -2513,6 +2513,42 @@ btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info) } /* + * Return the nearest left range of given start + * No ensure about the range will cover start. + */ +static struct data_rsv_range * +find_reserve_range(struct btrfs_qgroup_data_rsv_map *map, u64 start) +{ + struct rb_node **p = &map->root.rb_node; + struct rb_node *parent = NULL; + struct rb_node *prev = NULL; + struct data_rsv_range *range = NULL; + + while (*p) { + parent = *p; + range = rb_entry(parent, struct data_rsv_range, node); + if (range->start < start) + p = &(*p)->rb_right; + else if (range->start > start) + p = &(*p)->rb_left; + else + return range; + } + + /* empty tree */ + if (!parent) + return NULL; + if (range->start <= start) + return range; + + prev = rb_prev(parent); + /* Already most left one */ + if (!prev) + return range; + return rb_entry(prev, struct data_rsv_range, node); +} + +/* * Init data_rsv_map for a given inode. * * This is needed at write time as quota can be disabled and then enabled