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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 6EDA4C433DF for ; Tue, 16 Jun 2020 02:17:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5A6892071A for ; Tue, 16 Jun 2020 02:17:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726286AbgFPCRu (ORCPT ); Mon, 15 Jun 2020 22:17:50 -0400 Received: from mx2.suse.de ([195.135.220.15]:39564 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725978AbgFPCRu (ORCPT ); Mon, 15 Jun 2020 22:17:50 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 68670AE69 for ; Tue, 16 Jun 2020 02:17:53 +0000 (UTC) From: Qu Wenruo To: linux-btrfs@vger.kernel.org Subject: [PATCH 2/4] btrfs: detect uninitialized btrfs_root::anon_dev for user visible subvolumes Date: Tue, 16 Jun 2020 10:17:35 +0800 Message-Id: <20200616021737.44617-3-wqu@suse.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200616021737.44617-1-wqu@suse.com> References: <20200616021737.44617-1-wqu@suse.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 btrfs_root::anon_dev is an indicator for different subvolume namespaces. Thus it should always be initialized to an anonymous block device. Add a safe net to catch such uninitialized values. Signed-off-by: Qu Wenruo --- fs/btrfs/inode.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 00647e8cf2df..195aac71fe32 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -8697,6 +8697,7 @@ static int btrfs_getattr(const struct path *path, struct kstat *stat, { u64 delalloc_bytes; struct inode *inode = d_inode(path->dentry); + struct btrfs_root *root = BTRFS_I(inode)->root; u32 blocksize = inode->i_sb->s_blocksize; u32 bi_flags = BTRFS_I(inode)->flags; @@ -8718,7 +8719,13 @@ static int btrfs_getattr(const struct path *path, struct kstat *stat, STATX_ATTR_NODUMP); generic_fillattr(inode, stat); - stat->dev = BTRFS_I(inode)->root->anon_dev; + if (unlikely(!root->anon_dev)) { + WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG)); + btrfs_warn(root->fs_info, + "uninitialized btrfs_root::anon_dev detected, root=%llu", + root->root_key.objectid); + } + stat->dev = root->anon_dev; spin_lock(&BTRFS_I(inode)->lock); delalloc_bytes = BTRFS_I(inode)->new_delalloc_bytes; -- 2.27.0