Re: [PATCH v9 0/3] mm/gup: disallow GUP writing to file-backed mappings by default

[Christoph Hellwig]

On Sun, May 14, 2023 at 08:20:04PM +0100, Lorenzo Stoakes wrote:
> As discussed at LSF/MM, on the flight over I wrote a little repro [0] which
> reliably triggers the ext4 warning by recreating the scenario described
> above, using a small userland program and kernel module.
> 
> This code is not perfect (plane code :) but does seem to do the job
> adequately, also obviously this should only be run in a VM environment
> where data loss is acceptable (in my case a small qemu instance).

It would be really awesome if you could wire it up with and submit it
to xfstests.