Re: mbind() fails to fail with EIO

[Yang Shi <shy828301@gmail.com>]

On Tue, Mar 19, 2019 at 8:10 AM Oscar Salvador <osalvador@suse.de> wrote:
>
> On Tue, Mar 19, 2019 at 05:52:33PM +0300, Kirill A. Shutemov wrote:
> > On Tue, Mar 19, 2019 at 03:41:33PM +0100, Oscar Salvador wrote:
> > > On Tue, Mar 19, 2019 at 05:26:39PM +0300, Kirill A. Shutemov wrote:
> > > > That's all sounds reasonable.
> > > >
> > > > We only need to make sure the bug fixed by 77bf45e78050 will not be
> > > > re-introduced.
> > >
> > > I gave it a spin with the below patch.
> > > Your testcase works (so the bug is not re-introduced), and we get -EIO
> > > when running the ltp test [1].
> > > So unless I am missing something, it should be enough.
> >
> > Don't we need to bypass !vma_migratable(vma) check in
> > queue_pages_test_walk() for MPOL_MF_STRICT? I mean user still might want
> > to check if all pages are on the right not even the vma is not migratable.
>
> Yeah, I missed that.
> Then, I guess that we have to put the check into queue_pages_pte_range as well,
> and place it right before migrate_page_add().
> So, if it is not placed in the node and is not migreatable, we return -EIO.

Sorry, I didn't see this reply before I replied Kirill's email
earlier. Yes, I agree, it should return -EIO too.

Thanks,
Yang

>
> --
> Oscar Salvador
> SUSE L3