From patchwork Tue Dec 1 07:11:21 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qu Wenruo X-Patchwork-Id: 7733221 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 B1375BEEE1 for ; Tue, 1 Dec 2015 07:14:20 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 99E7F206AC for ; Tue, 1 Dec 2015 07:14:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 65229206AB for ; Tue, 1 Dec 2015 07:14:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755076AbbLAHOO (ORCPT ); Tue, 1 Dec 2015 02:14:14 -0500 Received: from cn.fujitsu.com ([59.151.112.132]:62711 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1755006AbbLAHOO (ORCPT ); Tue, 1 Dec 2015 02:14:14 -0500 X-IronPort-AV: E=Sophos;i="5.20,346,1444665600"; d="scan'208";a="1025397" Received: from unknown (HELO cn.fujitsu.com) ([10.167.250.3]) by heian.cn.fujitsu.com with ESMTP; 01 Dec 2015 15:14:02 +0800 Received: from localhost.localdomain (unknown [10.167.226.34]) by cn.fujitsu.com (Postfix) with ESMTP id 9863940444C2 for ; Tue, 1 Dec 2015 15:13:59 +0800 (CST) From: Qu Wenruo To: linux-btrfs@vger.kernel.org Subject: [PATCH v2 01/25] btrfs-progs: extent-cache: Add comments for search/lookup functions Date: Tue, 1 Dec 2015 15:11:21 +0800 Message-Id: <1448953905-28673-2-git-send-email-quwenruo@cn.fujitsu.com> X-Mailer: git-send-email 2.6.2 In-Reply-To: <1448953905-28673-1-git-send-email-quwenruo@cn.fujitsu.com> References: <1448953905-28673-1-git-send-email-quwenruo@cn.fujitsu.com> MIME-Version: 1.0 X-yoursite-MailScanner-Information: Please contact the ISP for more information X-yoursite-MailScanner-ID: 9863940444C2.AAAFD X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: quwenruo@cn.fujitsu.com 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 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP There are quite a lot search/lookup functions with different behavior, add comments for them, as it will take extra time to view source to understand the behavior difference. Signed-off-by: Qu Wenruo --- extent-cache.h | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/extent-cache.h b/extent-cache.h index cb1f77c..1ce68ef 100644 --- a/extent-cache.h +++ b/extent-cache.h @@ -45,11 +45,31 @@ struct cache_extent *last_cache_extent(struct cache_tree *tree); struct cache_extent *prev_cache_extent(struct cache_extent *pe); struct cache_extent *next_cache_extent(struct cache_extent *pe); +/* + * Find a cache_extent which covers start. + * + * If not found, return next cache_extent if possible. + */ struct cache_extent *search_cache_extent(struct cache_tree *tree, u64 start); + +/* + * Find a cahce_extent which restrictly covers start. + * + * If not found, return NULL. + */ struct cache_extent *lookup_cache_extent(struct cache_tree *tree, u64 start, u64 size); +/* + * Add an non-overlap extent into cache tree + * + * If [start, start+size) overlap with existing one, it will return -EEXIST. + */ int add_cache_extent(struct cache_tree *tree, u64 start, u64 size); + +/* + * Same with add_cache_extent, but with cache_extent strcut. + */ int insert_cache_extent(struct cache_tree *tree, struct cache_extent *pe); void remove_cache_extent(struct cache_tree *tree, struct cache_extent *pe); @@ -71,8 +91,19 @@ static void free_##name##_tree(struct cache_tree *tree) \ void free_extent_cache_tree(struct cache_tree *tree); +/* + * Search a cache_extent with same objectid, and covers start. + * + * If not found, return next if possible. + */ struct cache_extent *search_cache_extent2(struct cache_tree *tree, u64 objectid, u64 start); +/* + * Search a cache_extent with same objectid, and covers the range + * [start, start + size) + * + * If not found, return next cache_extent if possible. + */ struct cache_extent *lookup_cache_extent2(struct cache_tree *tree, u64 objectid, u64 start, u64 size); int add_cache_extent2(struct cache_tree *tree,