Re: [PATCH] block: Avoid mounting the bdev pseudo-filesystem in userspace

[Al Viro]

On Sun, May 24, 2026 at 11:07:18PM -0700, Christoph Hellwig wrote:
> On Thu, May 21, 2026 at 10:28:56AM +0300, Denis Arefev wrote:
> > The bdev pseudo-filesystem is an internal kernel filesystem with which
> > userspace should not interfere. Unregister it so that userspace cannot
> > even attempt to mount it.
> > 
> > This fixes a bug [1] that occurs when attempting to access files,
> > because the system call move_mount() uses pointers declared in the
> > inode_operations structure, which for the bdev pseudo-filesystem
> > are always equal to 0. `inode->i_op = &empty_iops;`
> 
> Looks good:

It really, really does not.  I would like to see the reproducer - analysis
looks like random noise out of LLM.

I've no real problem with removing that register_filesystem(), but if
it *does* fix some reproducer, I really want to see details.