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 C3444C35242 for ; Fri, 24 Jan 2020 14:33:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9AD9620661 for ; Fri, 24 Jan 2020 14:33:48 +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="y+82Ja5f" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404579AbgAXOdp (ORCPT ); Fri, 24 Jan 2020 09:33:45 -0500 Received: from mail-qt1-f195.google.com ([209.85.160.195]:46616 "EHLO mail-qt1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404420AbgAXOdh (ORCPT ); Fri, 24 Jan 2020 09:33:37 -0500 Received: by mail-qt1-f195.google.com with SMTP id e25so1608038qtr.13 for ; Fri, 24 Jan 2020 06:33:37 -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=y+82Ja5ffKbcoj4aBWSDmZ8dZUmV0L3G8Y1qwrxx/JeX39zM9uxcndkxO5RexlI/FX kDgzCBRYfypRATV8SpnzPtRb1iyCScvfFwGy52emG+8FR/naPBbwPyUdaQWGTGLDBWDG 4MB3mnkVZrq2BlSCnLGzyOWHH21qcP2723Vlim9B7NtIieTEi7OB09mArg3nfBNEx3c3 AXaUx4RpFrG3pyFO3buwd5EgiiTAuPN+QS1nSvzVWGRz+CBFFp6RClMJ48gEy7m/XvxO JH7NlZAXEpjk3i1Vc6OWv7T6XRixX7G+xa+/NDlhXvRt8MGBDLxR2B3NLYMta1zKOPvP OxQA== 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=tJe6RgRhwkbtH+NhTZ+zqyq8lsloortrFGhKtFVmwusGvd3Gi9B79htkXnZwCAMGsc R2hZ7k53hKGn7MQTPkMBPJejvLQYt9jQ0/tJ8X/6EoWK2ivLC6A82yLG/Svjne4Ls7P3 s/z6ezfEx2Pyl5T6ElUVHHiN/gtiVcu/3A0gE3MiiWB4Ez0+G0wmb9dKWvzQOjL4MxfU /RkQBoSKzYbfVVX07Q87RtKBV9XTmoGhk3BsCQu/rvT/O1NJFhE5NjNMoGXDOOxZdCvs QipA/YyclwqFMbr/4v54N9Y3y1SOPPXDN79HirFrBVfUBPDC7tzyr3VaaPZdc4eL7l0u k+Bg== X-Gm-Message-State: APjAAAU7yfMiWuMN3HZcIX6jFgD6O9g6zHRkMAAe+Nr9WxE73n868q29 C38GbiUVluxn0Wh52d2vjD2PJQ== X-Google-Smtp-Source: APXvYqxV+jUIUZhrHQCPWtnjJNCc+Pn5HYAAhHteXWAeQPStb6YUWr0k2fzLivoi2a5sW4uw79FRNA== X-Received: by 2002:ac8:7cb0:: with SMTP id z16mr2411754qtv.276.1579876416542; Fri, 24 Jan 2020 06:33:36 -0800 (PST) Received: from localhost ([107.15.81.208]) by smtp.gmail.com with ESMTPSA id v55sm713492qtc.1.2020.01.24.06.33.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 24 Jan 2020 06:33:35 -0800 (PST) From: Josef Bacik To: kernel-team@fb.com, linux-btrfs@vger.kernel.org Subject: [PATCH 20/44] btrfs: hold ref on root in btrfs_ioctl_default_subvol Date: Fri, 24 Jan 2020 09:32:37 -0500 Message-Id: <20200124143301.2186319-21-josef@toxicpanda.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200124143301.2186319-1-josef@toxicpanda.com> References: <20200124143301.2186319-1-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 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; -- 2.24.1