Re: [RFC PATCH] xen/privcmd: Convert get_user_pages*() to pin_user_pages*()

[Souptick Joarder <jrdr.linux@xxxxxxxxx>]

On Tue, Jun 23, 2020 at 12:40 AM Boris Ostrovsky
<boris.ostrovsky@xxxxxxxxxx> wrote:
>
> On 6/22/20 2:52 PM, Souptick Joarder wrote:
> >
> > I read the code again. I think, this check is needed to handle a scenario 
> > when
> > lock_pages() return -ENOSPC. Better to keep this check. Let me post v2 of 
> > this
> > RFC for a clear view.
>
>
> Actually, error handling seems to be somewhat broken here. If
> lock_pages() returns number of pinned pages then that's what we end up
> returning from privcmd_ioctl_dm_op(), all the way to user ioctl(). Which
> I don't think is right, we should return proper (negative) error.
>

What -ERRNO is more appropriate here ? -ENOSPC ?

>
> Do you mind fixing that we well? Then you should be able to avoid
> testing pages in a loop.

Ok, let me try to fix it.
>
>
> -boris
>