NACK: [SRU][UNSTABLE/FOCAL/BIONIC][PATCH v2] UBUNTU: SAUCE: shiftfs: fix dentry revalidation

[Christian Brauner]

On Wed, May 27, 2020 at 07:41:39PM +0100, James Troup wrote:
> Christian Brauner <christian.brauner at ubuntu.com> writes:
> 
> > Ok, here's a focal kernel master-next. It should include zfs and
> > hopefully i915 too:
> > https://drive.google.com/drive/u/1/folders/19iTwaFSYNS95_I-gD_rvFoV9cMAfy6io
> 
> OK, that's much better, thanks.  I'm booted into it now and
> unfortunately it doesn't solve the original problem...
> 
> After editing a file in emacs on the host:
> 
> 🙂 james at malefic:~/projects/tasta$ md5sum xxx.foo
> 5d56b88fddb21d4134eca0294dd76c79  xxx.foo
> 🙂 james at malefic:~/projects/tasta$
> 
> And in the lxc with the shifted FS:
> 
> ubuntu at portal:~/tasta$ md5sum xxx.foo
> 14758f1afd44c09b7992073ccf00b43d  xxx.foo
> ubuntu at portal:~/tasta$
> 
> 🙂 james at malefic:~/projects/tasta$ uname -a
> Linux malefic 5.4.0-33-generic #37 SMP Mon May 25 14:40:20 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
> 🙂 james at malefic:~/projects/tasta$ 

I'm not sure what's happening but I can't reproduce this at all. See:

https://asciinema.org/a/334491
https://asciinema.org/a/334492

What's the backing filesystem you're using, i.e. whats your host
filesystem? Any other details that might help?

Christian