From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-f193.google.com ([209.85.223.193]:36517 "EHLO mail-io0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932884AbcKXJ4V (ORCPT ); Thu, 24 Nov 2016 04:56:21 -0500 Received: by mail-io0-f193.google.com with SMTP id k19so4467001iod.3 for ; Thu, 24 Nov 2016 01:56:20 -0800 (PST) MIME-Version: 1.0 Reply-To: fdmanana@gmail.com In-Reply-To: <1479938294-3282-1-git-send-email-bo.li.liu@oracle.com> References: <1479938294-3282-1-git-send-email-bo.li.liu@oracle.com> From: Filipe Manana Date: Thu, 24 Nov 2016 09:56:19 +0000 Message-ID: Subject: Re: [PATCH v2] Btrfs: fix BUG_ON in btrfs_mark_buffer_dirty To: Liu Bo Cc: "linux-btrfs@vger.kernel.org" , David Sterba , Filipe Manana , Jeff Mahoney Content-Type: text/plain; charset=UTF-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Wed, Nov 23, 2016 at 9:58 PM, Liu Bo wrote: > 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 Reviewed-by: Filipe Manana Thanks 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 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Filipe David Manana, "People will forget what you said, people will forget what you did, but people will never forget how you made them feel."