From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:59538 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936937AbdADUHl (ORCPT ); Wed, 4 Jan 2017 15:07:41 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jeff Mahoney , Liu Bo , Filipe Manana Subject: [PATCH 4.9 03/83] Btrfs: fix BUG_ON in btrfs_mark_buffer_dirty Date: Wed, 4 Jan 2017 21:05:55 +0100 Message-Id: <20170104200446.697341343@linuxfoundation.org> In-Reply-To: <20170104200446.541604386@linuxfoundation.org> References: <20170104200446.541604386@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Liu Bo commit ef85b25e982b5bba1530b936e283ef129f02ab9d upstream. This can only happen with CONFIG_BTRFS_FS_CHECK_INTEGRITY=y. Commit 1ba98d0 ("Btrfs: detect corruption when non-root leaf has zero item") assumes that a leaf is its root when leaf->bytenr == btrfs_root_bytenr(root), however, we should not use btrfs_root_bytenr(root) since it's mainly got updated during committing transaction. So the check can fail when doing COW on this leaf while it is a root. This changes to use "if (leaf == btrfs_root_node(root))" instead, just like how we check whether leaf is a root in __btrfs_cow_block(). Fixes: 1ba98d086fe3 (Btrfs: detect corruption when non-root leaf has zero item) Reported-by: Jeff Mahoney Signed-off-by: Liu Bo Reviewed-by: Filipe Manana Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/disk-io.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -572,13 +572,17 @@ static noinline int check_leaf(struct bt * open_ctree() some roots has not yet been set up. */ if (!IS_ERR_OR_NULL(check_root)) { + struct extent_buffer *eb; + + eb = btrfs_root_node(check_root); /* if leaf is the root, then it's fine */ - if (leaf->start != - btrfs_root_bytenr(&check_root->root_item)) { + if (leaf != eb) { CORRUPT("non-root leaf's nritems is 0", - leaf, root, 0); + leaf, check_root, 0); + free_extent_buffer(eb); return -EIO; } + free_extent_buffer(eb); } return 0; }