[PATCH] nvme: module parameter to disable pi checks

[Christoph Hellwig]

On Wed, Oct 23, 2024 at 08:50:48AM -0700, Keith Busch wrote:
> From: Keith Busch <kbusch at kernel.org>
> 
> A recent commit enables integrity checks for formats the previous kernel
> versions registered with the "nop" integrity profile. This means
> namespaces using that format become unreadable when upgrading the kernel
> past that commit.
> 
> Introduce a module parameter to restore the "nop" integrity profile so
> that storage can be readable once again. This could be a boot device, so
> the setting needs to happen at module load time.

Not exactly a fan of module option, especially with such broad scope.
This will actually disable PI entirely as far as I can tell and not just
for the PI at the end of metadata formats.

Can we at least restrict it to those formats?  And maybe add a few
comments in the code why we have all this.