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

[Nadav Amit <nadav.amit@gmail.com>]

On Jun 23, 2022, at 2:57 PM, Peter Xu <peterx@redhat.com> wrote:

> 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?

I addressed these issues in the following patches - I messed up slightly the
patch order.

I will address these two into patch 1.

Regards,
Nadav