From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0440EC433EF for ; Wed, 15 Dec 2021 20:44:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236482AbhLOUn6 (ORCPT ); Wed, 15 Dec 2021 15:43:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54664 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235170AbhLOUn6 (ORCPT ); Wed, 15 Dec 2021 15:43:58 -0500 Received: from mail-qk1-x72c.google.com (mail-qk1-x72c.google.com [IPv6:2607:f8b0:4864:20::72c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B7012C061574 for ; Wed, 15 Dec 2021 12:43:57 -0800 (PST) Received: by mail-qk1-x72c.google.com with SMTP id de30so21389790qkb.0 for ; Wed, 15 Dec 2021 12:43:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=toxicpanda-com.20210112.gappssmtp.com; s=20210112; h=from:to:subject:date:message-id:in-reply-to:references:mime-version :content-transfer-encoding; bh=rWLAtjizEnheBFycFFLYahPAgWeIZaHLmkDO7UBlmv8=; b=2aiJuaGFvK2A4EFCDrBSk+pO53efiyADmffszvUqFYcbjyp7Ly0VBW5IkRHliWuVp0 20Z2QWzlrSlzZtlo/uGcI+zDvgS+pInAyD8T9dlyCyJSXWs1pbrDZRuVQIgr6GzKUOvq NBY9BvBkf37LobijqsjJCmVjOf0fJjfsry2qYSxVQaSbBdLFFicSKlNDQ8WLeRVVmYhT lKsWbWefxw6EtQm56KaDqjAycPRwH8dGCjSl2hRzHSwPp7jTwalgZzV5xqHJIZ8/HgRw glpu/GqZZH1HlH97NhNdkDLMmj7QOgNCRx0TS9txrkar40bXq1FokMsrJHKLdH7dRqSP 4f2A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=rWLAtjizEnheBFycFFLYahPAgWeIZaHLmkDO7UBlmv8=; b=X8id+CoB2wJu8fWCUDJbn8oaICYgQI18zSVzCzgoeiwLk9s8EEcUlYnEiNVO1Ujl+L S7WrCLGPt4xWXshANj4J38NFJntxt1TJZd93RdBeGpx9xrxGnNKhn4AdtHYdPWnkkReR h52d0mCoMWWgXOFHnDsWJkgO/TgYk5aR+OrBtwDcgxnQhJgFjVX1maSQlTVcWPnIVhKl LYqMujn1KW1QnIGMV1yndom/TXg4k+jK9ZNfu3IYr9q7eK5/NZZVdCgCJVIcmHzdNlsr f/RLXWV9K33X6eRH3FWQP6CWPsUHeoQ0aGhnS5FXcUZmZWTB8bVQSlyaqXl9J1pVS3UO M/jQ== X-Gm-Message-State: AOAM530ZhAcI5lsrg5Qo2Csct9icrhJ9LYtXqNchCA3gLjbdnQvmNKMW S47EsiI5J1kZDzKrvAwsPI4314kEJuGqXw== X-Google-Smtp-Source: ABdhPJwxnn3gFKPuZKiWobf+tEIHQOx7Mw8oe/BOUqacYe1HPriQMtFph/K2qAn+N2Y/k1GzZB17Kw== X-Received: by 2002:a37:c94:: with SMTP id 142mr10231299qkm.470.1639601036569; Wed, 15 Dec 2021 12:43:56 -0800 (PST) Received: from localhost (cpe-174-109-172-136.nc.res.rr.com. [174.109.172.136]) by smtp.gmail.com with ESMTPSA id o10sm2325606qtx.33.2021.12.15.12.43.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 15 Dec 2021 12:43:56 -0800 (PST) From: Josef Bacik To: linux-btrfs@vger.kernel.org, kernel-team@fb.com Subject: [PATCH 7/9] btrfs: add a btrfs_first_item helper Date: Wed, 15 Dec 2021 15:43:43 -0500 Message-Id: <42fa95e1cdbd30457dcec8c2b0a3f55966b133af.1639600854.git.josef@toxicpanda.com> X-Mailer: git-send-email 2.26.3 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org The GC tree stuff is going to use this helper and it'll make the code a bit cleaner to abstract this into a helper. Signed-off-by: Josef Bacik --- fs/btrfs/ctree.c | 23 +++++++++++++++++++++++ fs/btrfs/ctree.h | 1 + 2 files changed, 24 insertions(+) diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 781537692a4a..efb413a6db0c 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -4775,3 +4775,26 @@ int btrfs_previous_extent_item(struct btrfs_root *root, } return 1; } + +/** + * btrfs_first_item - search the given root for the first item. + * @root: the root to search. + * @path: the path to use for the search. + * @return: 0 if it found something, 1 if nothing was found and < on error. + * + * Search down and find the first item in a tree. If the root is empty return + * 1, otherwise we'll return 0 or < 0 if there was an error. + */ +int btrfs_first_item(struct btrfs_root *root, struct btrfs_path *path) +{ + struct btrfs_key key = {}; + int ret; + + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret > 0) { + if (btrfs_header_nritems(path->nodes[0]) == 0) + return 1; + ret = 0; + } + return ret; +} diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 2a5ed393eb21..6bcf112f9872 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -2892,6 +2892,7 @@ void btrfs_wait_for_snapshot_creation(struct btrfs_root *root); int btrfs_bin_search(struct extent_buffer *eb, const struct btrfs_key *key, int *slot); int __pure btrfs_comp_cpu_keys(const struct btrfs_key *k1, const struct btrfs_key *k2); +int btrfs_first_item(struct btrfs_root *root, struct btrfs_path *path); int btrfs_previous_item(struct btrfs_root *root, struct btrfs_path *path, u64 min_objectid, int type); -- 2.26.3