On Tue, Oct 10, 2023 at 4:34 PM Miklos Szeredi [off-list ref] wrote:

On Tue, 10 Oct 2023 at 15:17, Amir Goldstein [off-list ref] wrote:

quoted

Sorry, you asked about ovl mount.
To me it makes sense that if users observe ovl paths in writable mapped
memory, that ovl should not be remounted RO.
Anyway, I don't see a good reason to allow remount RO for ovl in that case.
Is there?

Agreed.

But is preventing remount RO important enough to warrant special
casing of backing file in generic code?  I'm not convinced either
way...

I prefer correctness and I doubt that the check
   if (unlikely(f->f_mode & FMODE_BACKING))
is worth optimizing.

but I will let Christian make the final call.

Thanks,
Amir.