Re: [PATCH v1 1/5] userfaultfd: introduce uffd_flags

[Peter Xu <peterx@redhat.com>]

On Wed, Jun 22, 2022 at 11:50:34AM -0700, Nadav Amit wrote:
> @@ -1891,7 +1902,7 @@ static int userfaultfd_continue(struct userfaultfd_ctx *ctx, unsigned long arg)
>  	if (mmget_not_zero(ctx->mm)) {
>  		ret = mcopy_continue(ctx->mm, uffdio_continue.range.start,
>  				     uffdio_continue.range.len,
> -				     &ctx->mmap_changing);
> +				     &ctx->mmap_changing, 0);

Shall we consistently use either 0 or UFFD_FLAGS_NONE?  I'd go for 0
directly since that's clearer on having "nothing" as flag.

>  		mmput(ctx->mm);
>  	} else {
>  		return -ESRCH;

[...]

>  ssize_t mfill_zeropage(struct mm_struct *dst_mm, unsigned long start,
> -		       unsigned long len, atomic_t *mmap_changing)
> +		       unsigned long len, atomic_t *mmap_changing,
> +		       uffd_flags_t uffd_flags)
>  {
>  	return __mcopy_atomic(dst_mm, start, 0, len, MCOPY_ATOMIC_ZEROPAGE,
>  			      mmap_changing, 0);

I think you agreed on passing the uffd_flags into __mcopy_atomic() (and
also below). Is it forgotten or plan changed?

Thanks,

>  }
>  
>  ssize_t mcopy_continue(struct mm_struct *dst_mm, unsigned long start,
> -		       unsigned long len, atomic_t *mmap_changing)
> +		       unsigned long len, atomic_t *mmap_changing,
> +		       uffd_flags_t uffd_flags)
>  {
>  	return __mcopy_atomic(dst_mm, start, 0, len, MCOPY_ATOMIC_CONTINUE,
>  			      mmap_changing, 0);
>  }

-- 
Peter Xu