Re: [PATCH v8 02/10] iov_iter: Add a function to extract a page list from an iterator

[David Hildenbrand]

On 24.01.23 15:45, David Howells wrote:
> David Hildenbrand <david@xxxxxxxxxx> wrote:
>
> > At least reduces the occurrences of FOLL_PIN :)
>
> I don't see where the problem is in letting people supply FOLL_PIN or
> FOLL_GET.  Why even have pin_user_pages() and get_user_pages() since they end
> up at the same place.  They should be inline wrappers, if separate functions
> at all.

There once was a proposed goal of restricting FOLL_GET to core-mm and 
allowing other drivers etc. to only use FOLL_PIN. Providing 
pin_user_pages() and the corresponding unpin part seemed very clean to me.

To me that makes perfect sense and will prevent any misuse once we 
converted everything relevant to FOLL_PIN.


To be precise, I think we could get away in this patch set by not using 
FOLL_PIN and FOLL_GET and it wouldn't really reduce readability of the 
code ...

--
Thanks,

David / dhildenb