On Wed, 21 Jun 2023 at 16:16, Muhammad Usama Anjum
<usama.anjum@xxxxxxxxxxxxx> wrote:
> On 6/21/23 6:42 PM, Michał Mirosław wrote:
> > On Wed, 21 Jun 2023 at 09:24, Muhammad Usama Anjum
> > <usama.anjum@xxxxxxxxxxxxx> wrote:
> > [...]
> >> +static int pagemap_scan_test_walk(unsigned long start, unsigned long end,
> >> + struct mm_walk *walk)
> >> +{
> >> + struct pagemap_scan_private *p = walk->private;
> >> + struct vm_area_struct *vma = walk->vma;
> >> +
> >> + if ((p->flags & PM_SCAN_REQUIRE_UFFD) && (!userfaultfd_wp_async(vma) ||
> >> + !userfaultfd_wp_use_markers(vma)))
> >> + return -EPERM;
> >> +
> >> + if (vma->vm_flags & VM_PFNMAP)
> >> + return 1;
> >> +
> >> + return 0;
> >> +}
> >
> > This could actually short-circuit all vma flags (e.g. IS_FILE): if
> > (required_mask & IS_FILE && vma is not file-backed) return 0;
> Sorry, unable to understand you. Should we do something here?
It seems I had an earlier version of the patch in my mind, where
PAGE_IS_FILE was based on vma type. Sorry for the noise.
Best Regards
Michał Mirosław
>
> >
> > Best Regards
> > Michał Mirosław
>
> --
> BR,
> Muhammad Usama Anjum
