Re: [RESEND 5/7] IB/hfi1: Use the new FOLL_LONGTERM flag to get_user_pages_fast()

[Ira Weiny]

On Fri, Mar 22, 2019 at 03:14:26PM -0700, Dan Williams wrote:
> On Sun, Mar 17, 2019 at 7:36 PM  wrote:
> >
> > From: Ira Weiny 
> >
> > Use the new FOLL_LONGTERM to get_user_pages_fast() to protect against
> > FS DAX pages being mapped.
> >
> > Signed-off-by: Ira Weiny 
> > ---
> >  drivers/infiniband/hw/hfi1/user_pages.c | 6 --
> >  1 file changed, 4 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/infiniband/hw/hfi1/user_pages.c 
> > b/drivers/infiniband/hw/hfi1/user_pages.c
> > index 78ccacaf97d0..6a7f9cd5a94e 100644
> > --- a/drivers/infiniband/hw/hfi1/user_pages.c
> > +++ b/drivers/infiniband/hw/hfi1/user_pages.c
> > @@ -104,9 +104,11 @@ int hfi1_acquire_user_pages(struct mm_struct *mm, 
> > unsigned long vaddr, size_t np
> > bool writable, struct page **pages)
> >  {
> > int ret;
> > +   unsigned int gup_flags = writable ? FOLL_WRITE : 0;
> 
> Maybe:
> 
> unsigned int gup_flags = FOLL_LONGTERM | (writable ? FOLL_WRITE : 0);
> 
> ?

Sure looks good.

Ira

> 
> >
> > -   ret = get_user_pages_fast(vaddr, npages, writable ? FOLL_WRITE : 0,
> > - pages);
> > +   gup_flags |= FOLL_LONGTERM;
> > +
> > +   ret = get_user_pages_fast(vaddr, npages, gup_flags, pages);
> > if (ret < 0)
> > return ret;
> >
> > --
> > 2.20.1
> >
> 

Re: [RESEND 5/7] IB/hfi1: Use the new FOLL_LONGTERM flag to get_user_pages_fast()

[Dan Williams]

On Sun, Mar 17, 2019 at 7:36 PM  wrote:
>
> From: Ira Weiny 
>
> Use the new FOLL_LONGTERM to get_user_pages_fast() to protect against
> FS DAX pages being mapped.
>
> Signed-off-by: Ira Weiny 
> ---
>  drivers/infiniband/hw/hfi1/user_pages.c | 6 --
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/infiniband/hw/hfi1/user_pages.c 
> b/drivers/infiniband/hw/hfi1/user_pages.c
> index 78ccacaf97d0..6a7f9cd5a94e 100644
> --- a/drivers/infiniband/hw/hfi1/user_pages.c
> +++ b/drivers/infiniband/hw/hfi1/user_pages.c
> @@ -104,9 +104,11 @@ int hfi1_acquire_user_pages(struct mm_struct *mm, 
> unsigned long vaddr, size_t np
> bool writable, struct page **pages)
>  {
> int ret;
> +   unsigned int gup_flags = writable ? FOLL_WRITE : 0;

Maybe:

unsigned int gup_flags = FOLL_LONGTERM | (writable ? FOLL_WRITE : 0);

?

>
> -   ret = get_user_pages_fast(vaddr, npages, writable ? FOLL_WRITE : 0,
> - pages);
> +   gup_flags |= FOLL_LONGTERM;
> +
> +   ret = get_user_pages_fast(vaddr, npages, gup_flags, pages);
> if (ret < 0)
> return ret;
>
> --
> 2.20.1
>