Re: [PATCH] mm/mmu_notifier: Remove unused mmu_notifier_range_update_to_read_only export

[Mike Rapoport <rppt@kernel.org>]

On Mon, Jan 09, 2023 at 12:22:07PM +1100, Alistair Popple wrote:
> mmu_notifier_range_update_to_read_only() was originally introduced in
> commit c6d23413f81b ("mm/mmu_notifier:
> mmu_notifier_range_update_to_read_only() helper") as an optimisation
> for device drivers that know a range has only been mapped
> read-only. However there are no users of this feature so remove it. As
> it is the only user of the struct mmu_notifier_range.vma field remove
> that also.
> 
> Signed-off-by: Alistair Popple <apopple@nvidia.com>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  include/linux/mmu_notifier.h |  2 --
>  mm/mmu_notifier.c            | 10 ----------
>  2 files changed, 12 deletions(-)
> 
> diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
> index d6c06e140277..252e44afcc70 100644
> --- a/include/linux/mmu_notifier.h
> +++ b/include/linux/mmu_notifier.h
> @@ -269,7 +269,6 @@ extern struct lockdep_map __mmu_notifier_invalidate_range_start_map;
>  #endif
>  
>  struct mmu_notifier_range {
> -	struct vm_area_struct *vma;
>  	struct mm_struct *mm;
>  	unsigned long start;
>  	unsigned long end;
> @@ -519,7 +518,6 @@ static inline void mmu_notifier_range_init(struct mmu_notifier_range *range,
>  					   unsigned long start,
>  					   unsigned long end)
>  {
> -	range->vma = vma;
>  	range->event = event;
>  	range->mm = mm;
>  	range->start = start;
> diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c
> index f45ff1b7626a..50c0dde1354f 100644
> --- a/mm/mmu_notifier.c
> +++ b/mm/mmu_notifier.c
> @@ -1120,13 +1120,3 @@ void mmu_notifier_synchronize(void)
>  	synchronize_srcu(&srcu);
>  }
>  EXPORT_SYMBOL_GPL(mmu_notifier_synchronize);
> -
> -bool
> -mmu_notifier_range_update_to_read_only(const struct mmu_notifier_range *range)
> -{
> -	if (!range->vma || range->event != MMU_NOTIFY_PROTECTION_VMA)
> -		return false;
> -	/* Return true if the vma still have the read flag set. */
> -	return range->vma->vm_flags & VM_READ;
> -}
> -EXPORT_SYMBOL_GPL(mmu_notifier_range_update_to_read_only);
> -- 
> 2.35.1
> 
> 

-- 
Sincerely yours,
Mike.