Aarch64 EXT4FS inode checksum failures - seems to be weak memory ordering issues

[Russell King - ARM Linux admin]

On Wed, Jan 06, 2021 at 05:20:34PM +0000, Will Deacon wrote:
> With that, I see the following after ten seconds or so:
> 
>   EXT4-fs error (device sda2): ext4_lookup:1707: inode #674497: comm md5sum: iget: checksum invalid
> 
> Russell, Mark -- does this recipe explode reliably for you too?

I've been working this evening on tracking down what change in the
Kconfig file between your working 5.10 kernel binary you supplied me,
and my failing 5.9 kernel.

I've found that _enabling_ CONFIG_STACKPROTECTOR appears to mask the
inode checksum failure problem, at least from a short test.) I'm going
to re-enable CONFIG_STACKPROTECTOR and leave it running for longer.

That is:

CONFIG_STACKPROTECTOR=y
CONFIG_STACKPROTECTOR_STRONG=y

appears to mask the problem

# CONFIG_STACKPROTECTOR is not set

appears to unmask the problem.

-- 
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