From patchwork Fri Jan 17 13:47:35 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Josef Bacik X-Patchwork-Id: 11339143 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8B6BA6C1 for ; Fri, 17 Jan 2020 13:48:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6A83C2082F for ; Fri, 17 Jan 2020 13:48:37 +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="u2jK+eDz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729050AbgAQNsh (ORCPT ); Fri, 17 Jan 2020 08:48:37 -0500 Received: from mail-qk1-f193.google.com ([209.85.222.193]:38071 "EHLO mail-qk1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729039AbgAQNsg (ORCPT ); Fri, 17 Jan 2020 08:48:36 -0500 Received: by mail-qk1-f193.google.com with SMTP id k6so22683310qki.5 for ; Fri, 17 Jan 2020 05:48:35 -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=PP4dVMcgyT8OTB+vOohtLtUZzvbmwfUKl46nd4xdSyk=; b=u2jK+eDz3VyfsBFMYcDxNH+LpuHoMUCSU+3vQQmFrkuYYo+MVCFhTPV1WsxQcDTcS0 ybZ7UuDTB+TSd2EvL0mDfHJMH/KCB6/AicoDAovbjL8QbMFdMhYcIt4JB7fzYwOESofX iu//K+FUHg8eIFvm8aCns4aT6PxNJDZOYRl0xGOnnp20sdoFq3z9wCb6MVcxXrxV4YtK AZ9gQ++Rlu8RjpYqTo4oKcZoLeyMV/9DlTZUnfqzwyexzPW8ovh5ZrRmLDGqRuozDlbW sfYJAIQWIn5ojAkNAlwXCSVNHW+4PTTUZav6vZjnRznzvKnK9hhFBGZ/69uuR8qABJiD Bp3w== 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=PP4dVMcgyT8OTB+vOohtLtUZzvbmwfUKl46nd4xdSyk=; b=JDuYwpW+O8etAj94XhmkIrtTXEC4reOuuIHOYKzgG8+wmrHbnVJxK4mSwTOJe8Sgul bZNW/lzHz+v2HPso8wYkjlsCOgSTnm8Q8uWwOjDYEKx3ab+HpFkgE/vleb2hASfHLVW/ ZvUg2Wp7ErpH3kYjVNDMIgirfZKN7n5H4e5p0CQ3UV+NsHdp4e+v629qa+aJA/WXrEgt h26hge5XwEAIU4R4PA3PeRHnqY4/Y80BdpXf8U46k4PM0S9MTd1YUcpD//Vdmz2f3jI2 2Y3Yqm+sl7UcIuE56xU5TqI8h/7q3n4x5DPxwtJIx/uSnDdlj63YGVvmAHVqx+oJQx+0 qnVg== X-Gm-Message-State: APjAAAU/x5ul6VvnuNOYkBOSAM1yOCv2wwo8mSFSQkzKilmea0HkbeDA RpklV7EwqWl2oPC13qPPtzf1tjS/MbV2YQ== X-Google-Smtp-Source: APXvYqzDVFkjghhn3yyGAOATE7nD941GpqTq+msILLPpoOgMRVgii+vjFpRocPOIvZwVYCfVFSZdQA== X-Received: by 2002:a05:620a:13e7:: with SMTP id h7mr39093643qkl.235.1579268914688; Fri, 17 Jan 2020 05:48:34 -0800 (PST) Received: from localhost ([107.15.81.208]) by smtp.gmail.com with ESMTPSA id s26sm12055091qkj.24.2020.01.17.05.48.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 17 Jan 2020 05:48:34 -0800 (PST) From: Josef Bacik To: linux-btrfs@vger.kernel.org, kernel-team@fb.com Subject: [PATCH 20/43] btrfs: hold ref on root in btrfs_ioctl_default_subvol Date: Fri, 17 Jan 2020 08:47:35 -0500 Message-Id: <20200117134758.41494-21-josef@toxicpanda.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200117134758.41494-1-josef@toxicpanda.com> References: <20200117134758.41494-1-josef@toxicpanda.com> MIME-Version: 1.0 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 7d30c7821490..69c39b3d15a5 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -3987,7 +3987,7 @@ 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; @@ -4018,44 +4018,50 @@ 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;