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 99039C43603 for ; Tue, 17 Dec 2019 15:37:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6B23E24655 for ; Tue, 17 Dec 2019 15:37:20 +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="Xfly9CHM" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728550AbfLQPhT (ORCPT ); Tue, 17 Dec 2019 10:37:19 -0500 Received: from mail-qt1-f196.google.com ([209.85.160.196]:35457 "EHLO mail-qt1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728150AbfLQPhT (ORCPT ); Tue, 17 Dec 2019 10:37:19 -0500 Received: by mail-qt1-f196.google.com with SMTP id e12so3933529qto.2 for ; Tue, 17 Dec 2019 07:37:18 -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=wa/TiQ9rxnUiJWYhskdyV3ZEJ3PZuit08QhB03+OCzQ=; b=Xfly9CHMmbnCPObzghXQ5IhbrVREeyuEcL19CeHo6YrJyzHnln2aXLG/UJU2iE70s0 yKlHs0pKTnUDH+ECaP7PAZ0u8o4+jOsYWmf6m4I0MsmVxcqHLAadHiA+285KvJgXEXR0 BUgvKrfRQ8Z+r//OlphB10Dh4vnB+L6KV2moB06mjpjP3XeV8QSI7RDKgQFZA55NbLdM 0LrWTSECSR3VdxuouYid5YAMYq6U/GYW8W/0XSabDRc1Tp8ucAWyS0wkXeLX0pIxPBHI ncHBW4TqyxQRXrLI9G+k3pvFCtHWbS9YQUJTcnAuWDP3qaq0UxJEdH1ExcKRwGnPInS7 E1Xw== 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=wa/TiQ9rxnUiJWYhskdyV3ZEJ3PZuit08QhB03+OCzQ=; b=Pc2M8gQGzB50Un8Ctk3ui9xEeBPlh5xBWFjCgh0/q0YMJCQc9TwAGLVASVEXZiPRZ/ SiA8MkzfLhcgXEjE6UN0WZw0eCEt4f1n+KrIde+Y6z502tf/j/LP0dWvoMSYkFzuIYCn yiapo9tfzM334EPbNxikb+CWPFO7IA0vtFeP9gk5bMj7BS21WvqShXCrYrbMKp/lPNHQ B/rBVQ0dXid9jlKgC+8CEMc5ZnqcKSU22c1XU/+FVcTIavG+VEyLOHgxTIjy8nIZPjNT mM08thE4+0Fp5uhCakkJEyzfmOUAxaPMWvKk0RoSnguvrL2e5wDWwH6WWX+oeA/q/ti9 QVrQ== X-Gm-Message-State: APjAAAVjd4N42nYYUev9Uxlm+9MiWSFA7XXfS6PRwZ9YKiP/5VTtX6Me 5ZexxrkRNpBFokpXKqifb5ez5UHem//H1g== X-Google-Smtp-Source: APXvYqy0zWNs0be6+ulRTeP6gFyfBJRPV2Kkn0Z6KYR+Ftw0n5pC9UbW5oxHRuQAp8MJwU0cCypBbg== X-Received: by 2002:ac8:7b4f:: with SMTP id m15mr5115601qtu.48.1576597038135; Tue, 17 Dec 2019 07:37:18 -0800 (PST) Received: from localhost ([107.15.81.208]) by smtp.gmail.com with ESMTPSA id c13sm6792936qko.87.2019.12.17.07.37.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 17 Dec 2019 07:37:17 -0800 (PST) From: Josef Bacik To: linux-btrfs@vger.kernel.org, kernel-team@fb.com Subject: [PATCH 22/45] btrfs: hold ref on root in btrfs_ioctl_default_subvol Date: Tue, 17 Dec 2019 10:36:12 -0500 Message-Id: <20191217153635.44733-23-josef@toxicpanda.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191217153635.44733-1-josef@toxicpanda.com> References: <20191217153635.44733-1-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 We look up an arbitrary fs root here, we need to hold a ref on the root for the duration. Signed-off-by: Josef Bacik --- fs/btrfs/ioctl.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 2797a1249f25..a3223bec3f5b 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -3993,7 +3993,7 @@ static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp) struct btrfs_root *new_root; struct btrfs_dir_item *di; struct btrfs_trans_handle *trans; - struct btrfs_path *path; + struct btrfs_path *path = NULL; struct btrfs_key location; struct btrfs_disk_key disk_key; u64 objectid = 0; @@ -4024,44 +4024,50 @@ static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp) ret = PTR_ERR(new_root); goto out; } - if (!is_fstree(new_root->root_key.objectid)) { + if (!btrfs_grab_fs_root(root)) { ret = -ENOENT; goto out; } + if (!is_fstree(new_root->root_key.objectid)) { + ret = -ENOENT; + goto out_free; + } path = btrfs_alloc_path(); if (!path) { ret = -ENOMEM; - goto out; + goto out_free; } path->leave_spinning = 1; trans = btrfs_start_transaction(root, 1); if (IS_ERR(trans)) { - btrfs_free_path(path); ret = PTR_ERR(trans); - goto out; + goto out_free; } dir_id = btrfs_super_root_dir(fs_info->super_copy); di = btrfs_lookup_dir_item(trans, fs_info->tree_root, path, dir_id, "default", 7, 1); if (IS_ERR_OR_NULL(di)) { - btrfs_free_path(path); + btrfs_release_path(path); btrfs_end_transaction(trans); btrfs_err(fs_info, "Umm, you don't have the default diritem, this isn't going to work"); ret = -ENOENT; - goto out; + goto out_free; } btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key); btrfs_set_dir_item_key(path->nodes[0], di, &disk_key); btrfs_mark_buffer_dirty(path->nodes[0]); - btrfs_free_path(path); + btrfs_release_path(path); btrfs_set_fs_incompat(fs_info, DEFAULT_SUBVOL); btrfs_end_transaction(trans); +out_free: + btrfs_put_fs_root(new_root); + btrfs_free_path(path); out: mnt_drop_write_file(file); return ret; -- 2.23.0