Re: [PATCH v4 07/66] mm: Add VMA iterator

[Vlastimil Babka]

On 12/1/21 15:29, Liam Howlett wrote:
> From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
> 
> This thin layer of abstraction over the maple tree state is for
> iterating over VMAs.  You can go forwards, go backwards or ask where
> the iterator is.  Rename the existing vma_next() to __vma_next() --
> it will be removed by the end of this series.
> 
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>

Acked-by: Vlastimil Babka <vbabka@xxxxxxx>

With a question below.

> ---
>  include/linux/mm.h       | 27 +++++++++++++++++++++++++++
>  include/linux/mm_types.h | 21 +++++++++++++++++++++
>  mm/mmap.c                | 10 +++++-----
>  3 files changed, 53 insertions(+), 5 deletions(-)
> 
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 9eae78a155be..acdccbe9b96b 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -696,6 +696,33 @@ static inline bool vma_is_accessible(struct vm_area_struct *vma)
>  	return vma->vm_flags & VM_ACCESS_FLAGS;
>  }
>  
> +static inline
> +struct vm_area_struct *vma_find(struct vma_iterator *vmi, unsigned long max)
> +{
> +	return mas_find(&vmi->mas, max);
> +}
> +
> +static inline struct vm_area_struct *vma_next(struct vma_iterator *vmi)
> +{
> +	return vma_find(vmi, ULONG_MAX);

Why not mas_next()?

> +}
> +
> +static inline struct vm_area_struct *vma_prev(struct vma_iterator *vmi)
> +{
> +	return mas_prev(&vmi->mas, 0);
> +}
> +
> +static inline unsigned long vma_iter_addr(struct vma_iterator *vmi)
> +{
> +	return vmi->mas.index;
> +}
> +
> +#define for_each_vma(vmi, vma)		while ((vma = vma_next(&vmi)) != NULL)
> +