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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B9DAAC33CB1 for ; Fri, 17 Jan 2020 13:52:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 92129206E6 for ; Fri, 17 Jan 2020 13:52:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=toxicpanda-com.20150623.gappssmtp.com header.i=@toxicpanda-com.20150623.gappssmtp.com header.b="oU5uA7BJ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727691AbgAQNww (ORCPT ); Fri, 17 Jan 2020 08:52:52 -0500 Received: from mail-qt1-f194.google.com ([209.85.160.194]:36780 "EHLO mail-qt1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726885AbgAQNwv (ORCPT ); Fri, 17 Jan 2020 08:52:51 -0500 Received: by mail-qt1-f194.google.com with SMTP id i13so21809074qtr.3 for ; Fri, 17 Jan 2020 05:52:51 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=toxicpanda-com.20150623.gappssmtp.com; s=20150623; h=from:to:subject:date:message-id:in-reply-to:references:mime-version :content-transfer-encoding; bh=/zdI4VuyspYsK8Ci42qtnrQTm+M6cKNrl1u50QcG7C0=; b=oU5uA7BJ7mHnzoW1WplRFfF+Siy/Ivi+5IUhKfEB9IfKiBKJjuRGzgk8QlXEDOf1V7 ZA6XIVknR9Gu1voNxd0gI+Ae8ioh6XdwcEHnsxANnThbG4y/ye5C2ChliGeXYOnEje/A 6WulbOFeetd0K/lz7XdOWawRCS/QiBSs/nBCz0Rb531ORZwo3F5RHgbWcctXsrojo3GE HwQoEQcJYqew63dQ/rdybRXQQ7H9YozQgZw8GJp6JAWzr99xFm/PmgOAusmlgIC4dkRv 3s92pGIhla2Aa7bJ10v9bV//AcCBahj2NzDfynUrqQBWVVg7rgGfQvXKHH/JTN/WrT1s IqEA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=/zdI4VuyspYsK8Ci42qtnrQTm+M6cKNrl1u50QcG7C0=; b=Bw8uD0b2BR2tf2cekZxE/nyRINck8ocmhSYMcKaoBEDvgQv0t70BLrJNIbqIYYB30h 3Q9L5xi8H7JsGDVKRY7O9LloUZOyoZJSHAnjGV00pGin9Jn/S2biAAUH8fdMKp2oX27H zDr1UauaqFdzYoje2FtorhaF8IrzQpZTDGHO21M8dPGwS+EgTPZbvO0Z7M7CLS6aij2l a1vYWZHGT6WnzOY/f4fMokOImmFgBmb5O+Duq/rFTi/2HAOgbEo56KyZRS2ixY5RSltU YjpiMEsaiRtfI+v/fDcxGuvNAH7BDPSj/1wEF9bGnXWs54WJvEyThjuJ7StUtWdw8cH+ UpTA== X-Gm-Message-State: APjAAAW2ufXayzG6HGRSAZxHULeYhK0K8mrPQJSzwz18UtN7zPi2Ju1+ 2YasQWMKT3tHp5aTDC8Z2MQCEvhDYJv4Bg== X-Google-Smtp-Source: APXvYqz8FvicBe+tb70MRBY7uVCCt3daNSuWo11VTPyHJ5IQKfOKupKYWzbiJWJOpeI84b62eNDDVA== X-Received: by 2002:ac8:47c1:: with SMTP id d1mr7374902qtr.84.1579269170506; Fri, 17 Jan 2020 05:52:50 -0800 (PST) Received: from localhost ([107.15.81.208]) by smtp.gmail.com with ESMTPSA id e2sm11555436qkb.112.2020.01.17.05.52.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 17 Jan 2020 05:52:49 -0800 (PST) From: Josef Bacik To: linux-btrfs@vger.kernel.org, kernel-team@fb.com Subject: [PATCH 6/8] btrfs: don't take an extra root ref at allocation time Date: Fri, 17 Jan 2020 08:52:36 -0500 Message-Id: <20200117135238.41601-7-josef@toxicpanda.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200117135238.41601-1-josef@toxicpanda.com> References: <20200117135238.41601-1-josef@toxicpanda.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Now that all the users of roots take references for them we can drop the extra root ref we've been taking. Before we had roots at 2 refs for the life of the file system, one for the radix tree, and one simply for existing. Now that we have proper ref accounting in all places that use roots we can drop this extra ref simply for existing as we no longer need it. Signed-off-by: Josef Bacik --- fs/btrfs/disk-io.c | 20 ++++++-------------- fs/btrfs/tests/qgroup-tests.c | 2 ++ 2 files changed, 8 insertions(+), 14 deletions(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index be9b1a1b1a33..42f352dfca45 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1647,22 +1647,11 @@ struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info, if (ret == 0) set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state); - /* - * All roots have two refs on them at all times, one for the mounted fs, - * and one for being in the radix tree. This way we only free the root - * when we are unmounting or deleting the subvolume. We get one ref - * from __setup_root, one for inserting it into the radix tree, and then - * we have the third for returning it, and the caller will put it when - * it's done with the root. - */ - btrfs_grab_root(root); ret = btrfs_insert_fs_root(fs_info, root); if (ret) { btrfs_put_root(root); - if (ret == -EEXIST) { - btrfs_put_root(root); + if (ret == -EEXIST) goto again; - } goto fail; } return root; @@ -3897,11 +3886,13 @@ int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors) void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root) { + bool drop_ref = false; + spin_lock(&fs_info->fs_roots_radix_lock); radix_tree_delete(&fs_info->fs_roots_radix, (unsigned long)root->root_key.objectid); if (test_and_clear_bit(BTRFS_ROOT_IN_RADIX, &root->state)) - btrfs_put_root(root); + drop_ref = true; spin_unlock(&fs_info->fs_roots_radix_lock); if (btrfs_root_refs(&root->root_item) == 0) @@ -3923,7 +3914,8 @@ void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info, iput(root->ino_cache_inode); root->ino_cache_inode = NULL; } - btrfs_put_root(root); + if (drop_ref) + btrfs_put_root(root); } int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info) diff --git a/fs/btrfs/tests/qgroup-tests.c b/fs/btrfs/tests/qgroup-tests.c index ac035a6fa003..ce1ca8e73c2d 100644 --- a/fs/btrfs/tests/qgroup-tests.c +++ b/fs/btrfs/tests/qgroup-tests.c @@ -507,6 +507,7 @@ int btrfs_test_qgroups(u32 sectorsize, u32 nodesize) test_err("couldn't insert fs root %d", ret); goto out; } + btrfs_put_root(tmp_root); tmp_root = btrfs_alloc_dummy_root(fs_info); if (IS_ERR(tmp_root)) { @@ -521,6 +522,7 @@ int btrfs_test_qgroups(u32 sectorsize, u32 nodesize) test_err("couldn't insert fs root %d", ret); goto out; } + btrfs_put_root(tmp_root); test_msg("running qgroup tests"); ret = test_no_shared_qgroup(root, sectorsize, nodesize); -- 2.24.1