From patchwork Fri Dec 8 15:06:25 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nikolay Borisov X-Patchwork-Id: 10102745 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id E3CB6602A0 for ; Fri, 8 Dec 2017 15:06:46 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CDA0D212DB for ; Fri, 8 Dec 2017 15:06:46 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C276E26222; Fri, 8 Dec 2017 15:06:46 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4EF4C212DB for ; Fri, 8 Dec 2017 15:06:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754092AbdLHPGa (ORCPT ); Fri, 8 Dec 2017 10:06:30 -0500 Received: from mx2.suse.de ([195.135.220.15]:46039 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753933AbdLHPG2 (ORCPT ); Fri, 8 Dec 2017 10:06:28 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id A8B7CABB4 for ; Fri, 8 Dec 2017 15:06:27 +0000 (UTC) From: Nikolay Borisov To: linux-btrfs@vger.kernel.org Cc: Nikolay Borisov Subject: [PATCH] btrfs: Improve btrfs_search_slot description Date: Fri, 8 Dec 2017 17:06:25 +0200 Message-Id: <1512745585-19969-1-git-send-email-nborisov@suse.com> X-Mailer: git-send-email 2.7.4 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Signed-off-by: Nikolay Borisov --- fs/btrfs/ctree.c | 32 ++++++++++++++++++++++---------- 1 file changed, 22 insertions(+), 10 deletions(-) diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 880f4f693263..1f001d31bda8 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -2653,18 +2653,30 @@ int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *path, return 0; } -/* - * look for key in the tree. path is filled in with nodes along the way - * if key is found, we return zero and you can find the item in the leaf - * level of the path (level 0) +/* btrfs_search_slot - look for a key in a tree and perform necessary + * modifications to preserve tree invariants. + * + * @trans: Handle of transaction, used when modifying the tree + * @p: Holds all btree nodes along the search path + * @root: The root node of the tree + * @key: The key we are looking for + * @ins_len: Indicates purpose of search, for inserts it is 1, for + * deletions it's -1. 0 for plain searches + * @cow: boolean should CoW operations be performed. Must always be 1 + * when modifying the tree. + * + * If @ins_len > 0, nodes and leaves will be split as we walk down the tree. + * If @ins_len < 0, nodes will be merged as we walk down the tree (if possible) + * + * If @key is found, 0 is returned and you can find the item in the leaf level + * of the path (level 0) * - * If the key isn't found, the path points to the slot where it should - * be inserted, and 1 is returned. If there are other errors during the - * search a negative error number is returned. + * If @key isn't found, 1 is returned and the leaf level of the path (level 0) + * points to the slot where it should be inserted + * be inserted, and 1 is returned. * - * if ins_len > 0, nodes and leaves will be split as we walk down the - * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if - * possible) + * If an error is encountered while searching the tree a negative error number + * is returned */ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root, const struct btrfs_key *key, struct btrfs_path *p,