From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from aserp1040.oracle.com ([141.146.126.69]:29889 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753460AbcKWVve (ORCPT ); Wed, 23 Nov 2016 16:51:34 -0500 From: Liu Bo To: linux-btrfs@vger.kernel.org Cc: David Sterba , Filipe Manana , Jeff Mahoney Subject: [PATCH v2] Btrfs: fix BUG_ON in btrfs_mark_buffer_dirty Date: Wed, 23 Nov 2016 13:58:14 -0800 Message-Id: <1479938294-3282-1-git-send-email-bo.li.liu@oracle.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: 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) Cc: stable@vger.kernel.org # 4.8+ Reported-by: Jeff Mahoney Signed-off-by: Liu Bo --- v2: Tag itself for stable. fs/btrfs/disk-io.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 9367c31..b401e6d 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -572,13 +572,17 @@ static noinline int check_leaf(struct btrfs_root *root, * 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; } -- 2.5.5