linux-ext4 - Re: [PATCH] tune2fs: Update overhead when toggling journal feature

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 15 Jun 2021 09:52:32 +0200
From:   Jan Kara <jack@...e.cz>
To:     Andreas Dilger <adilger@...ger.ca>
Cc:     Jan Kara <jack@...e.cz>, Ted Tso <tytso@....edu>,
        Ext4 Developers List <linux-ext4@...r.kernel.org>
Subject: Re: [PATCH] tune2fs: Update overhead when toggling journal feature

On Mon 14-06-21 15:38:57, Andreas Dilger wrote:
> 
> > On Jun 14, 2021, at 3:28 PM, Jan Kara <jack@...e.cz> wrote:
> > 
> > When adding or removing journal from a filesystem, we also need to add /
> > remove journal blocks from overhead stored in the superblock.  Otherwise
> > total number of blocks in the filesystem as reported by statfs(2) need
> > not match reality and could lead to odd results like negative number of
> > used blocks reported by df(1).
> > 
> > Signed-off-by: Jan Kara <jack@...e.cz>
> 
> You could add:
> 
> Fixes: 9046b4dfd0ce ("mke2fs: set overhead in super block")
> 
> and
> 
> Reviewed-by: Andreas Dilger <adilger@...ger.ca>

Thanks!

> That also makes me wonder if resize2fs also needs to recalculate or
> invalidate the s_overhead_clusters field when adding new block groups.
> It *looks* like that is done correctly in adjust_fs_info() already?

Yes. From a quick look I had when doing this tune2fs patch I've noticed
that adjust_fs_info() just zeros s_overhead_clusters which makes the kernel
compute the overhead instead...

								Honza

-- 
Jan Kara <jack@...e.com>
SUSE Labs, CR