Re: [PATCHv2 1/9] mm: Introduce new vm_insert_range and vm_insert_range_buggy API

Mike Rapoport
2019-02-07T16:04:50Z

On Thu, Feb 07, 2019 at 09:37:08PM +0530, Souptick Joarder wrote:
> On Thu, Feb 7, 2019 at 9:27 PM Mike Rapoport <rppt-tEXmvtCZX7AybS5Ee8rs3A@public.gmane.org> wrote:
> >
> > Hi Souptick,
> >
> > On Thu, Feb 07, 2019 at 09:19:47PM +0530, Souptick Joarder wrote:
> > > Hi Mike,
> > >
> > > Just thought to take opinion for documentation before placing it in v3.
> > > Does it looks fine ?
> >
> > Overall looks good to me. Several minor points below.
>
> Thanks Mike. Noted.
> Shall I consider it as *Reviewed-by:* with below changes ?

Yeah, sure.

> >
> > > +/**
> > > + * __vm_insert_range - insert range of kernel pages into user vma
> > > + * @vma: user vma to map to
> > > + * @pages: pointer to array of source kernel pages
> > > + * @num: number of pages in page array
> > > + * @offset: user's requested vm_pgoff
> > > + *
> > > + * This allow drivers to insert range of kernel pages into a user vma.
> >
> > allows
> > > + *
> > > + * Return: 0 on success and error code otherwise.
> > > + */
> > > +static int __vm_insert_range(struct vm_area_struct *vma, struct page **pages,
> > > + unsigned long num, unsigned long offset)
> > >
> > >
> > > +/**
> > > + * vm_insert_range - insert range of kernel pages starts with non zero offset
> > > + * @vma: user vma to map to
> > > + * @pages: pointer to array of source kernel pages
> > > + * @num: number of pages in page array
> > > + *
> > > + * Maps an object consisting of `num' `pages', catering for the user's
> > @num pages
> > > + * requested vm_pgoff
> > > + *
> > > + * If we fail to insert any page into the vma, the function will return
> > > + * immediately leaving any previously inserted pages present. Callers
> > > + * from the mmap handler may immediately return the error as their caller
> > > + * will destroy the vma, removing any successfully inserted pages. Other
> > > + * callers should make their own arrangements for calling unmap_region().
> > > + *
> > > + * Context: Process context. Called by mmap handlers.
> > > + * Return: 0 on success and error code otherwise.
> > > + */
> > > +int vm_insert_range(struct vm_area_struct *vma, struct page **pages,
> > > + unsigned long num)
> > >
> > >
> > > +/**
> > > + * vm_insert_range_buggy - insert range of kernel pages starts with zero offset
> > > + * @vma: user vma to map to
> > > + * @pages: pointer to array of source kernel pages
> > > + * @num: number of pages in page array
> > > + *
> > > + * Similar to vm_insert_range(), except that it explicitly sets @vm_pgoff to
> >
> > the offset
> >
> > > + * 0. This function is intended for the drivers that did not consider
> > > + * @vm_pgoff.
> > > + *
> > > + * Context: Process context. Called by mmap handlers.
> > > + * Return: 0 on success and error code otherwise.
> > > + */
> > > +int vm_insert_range_buggy(struct vm_area_struct *vma, struct page **pages,
> > > + unsigned long num)
> > >
> >
> > --
> > Sincerely yours,
> > Mike.
> >
>

--
Sincerely yours,
Mike.