linux-ext4 - Re: [kernel-5.11 regression] tune2fs fails after shutdown

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Date:   Thu, 12 Aug 2021 09:47:30 +0800
From:   Boyang Xue <bxue@...hat.com>
To:     linux-ext4@...r.kernel.org, Jan Kara <jack@...e.cz>
Cc:     tytso@....edu
Subject: Re: [kernel-5.11 regression] tune2fs fails after shutdown

(Adding the author of the commits)

Hi Jan,

The commit

81414b4dd48 ext4: remove redundant sb checksum recomputation

breaks the original reproducer of

4274f516d4bc ext4: recalucate superblock checksum after updating free
blocks/inodes

I'm wondering is it expected please?

Thanks,
Boyang

On Thu, Aug 5, 2021 at 10:35 AM Boyang Xue <bxue@...hat.com> wrote:
>
> Hi,
>
> kernel commit
>
> 4274f516d4bc ext4: recalucate superblock checksum after updating free
> blocks/inodes
>
> had been reverted by
>
> 81414b4dd48 ext4: remove redundant sb checksum recomputation
>
> since kernel-5.11-rc1. As a result, the original reproducer fails again.
>
> Reproducer:
> ```
> mkdir mntpt
> fallocate -l 256M mntpt.img
> mkfs.ext4 -Fq -t ext4 mntpt.img 128M
> LPDEV=$(losetup -f --show mntpt.img)
> mount "$LPDEV" mntpt
> cp /proc/version mntpt/
> ./godown mntpt # godown program attached.
> umount mntpt
> mount "$LPDEV" mntpt
> tune2fs -l "$LPDEV"
> ```
>
> tune2fs fails with
> ```
> tune2fs 1.46.2 (28-Feb-2021)
> tune2fs: Superblock checksum does not match superblock while trying to
> open /dev/loop0
> Couldn't find valid filesystem superblock.
> ```
>
> Tested on e2fsprogs-1.46.2 + kernel-5.14.0-0.rc3.29. I think it's a
> regression. If this is the case, can we fix it again please?
>
> Thanks,
> Boyang