Re: [PATCH 5/8] mm/rmap: make anon_vma functions internal

[Suren Baghdasaryan <surenb@google.com>]

On Wed, Dec 17, 2025 at 4:27 AM Lorenzo Stoakes
<lorenzo.stoakes@oracle.com> wrote:
>
> The bulk of the anon_vma operations are only used by mm, so formalise this
> by putting the function prototypes and inlines in mm/internal.h. This
> allows us to make changes without having to worry about the rest of the
> kernel.
>
> Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>

Reviewed-by: Suren Baghdasaryan <surenb@google.com>

> ---
>  include/linux/rmap.h | 60 --------------------------------------------
>  mm/internal.h        | 58 ++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 58 insertions(+), 60 deletions(-)
>
> diff --git a/include/linux/rmap.h b/include/linux/rmap.h
> index 832bfc0ccfc6..dd764951b03d 100644
> --- a/include/linux/rmap.h
> +++ b/include/linux/rmap.h
> @@ -104,68 +104,8 @@ enum ttu_flags {
>  };
>
>  #ifdef CONFIG_MMU
> -static inline void get_anon_vma(struct anon_vma *anon_vma)
> -{
> -       atomic_inc(&anon_vma->refcount);
> -}
> -
> -void __put_anon_vma(struct anon_vma *anon_vma);
> -
> -static inline void put_anon_vma(struct anon_vma *anon_vma)
> -{
> -       if (atomic_dec_and_test(&anon_vma->refcount))
> -               __put_anon_vma(anon_vma);
> -}
> -
> -static inline void anon_vma_lock_write(struct anon_vma *anon_vma)
> -{
> -       down_write(&anon_vma->root->rwsem);
> -}
>
> -static inline int anon_vma_trylock_write(struct anon_vma *anon_vma)
> -{
> -       return down_write_trylock(&anon_vma->root->rwsem);
> -}
> -
> -static inline void anon_vma_unlock_write(struct anon_vma *anon_vma)
> -{
> -       up_write(&anon_vma->root->rwsem);
> -}
> -
> -static inline void anon_vma_lock_read(struct anon_vma *anon_vma)
> -{
> -       down_read(&anon_vma->root->rwsem);
> -}
> -
> -static inline int anon_vma_trylock_read(struct anon_vma *anon_vma)
> -{
> -       return down_read_trylock(&anon_vma->root->rwsem);
> -}
> -
> -static inline void anon_vma_unlock_read(struct anon_vma *anon_vma)
> -{
> -       up_read(&anon_vma->root->rwsem);
> -}
> -
> -
> -/*
> - * anon_vma helper functions.
> - */
>  void anon_vma_init(void);      /* create anon_vma_cachep */
> -int  __anon_vma_prepare(struct vm_area_struct *);
> -void unlink_anon_vmas(struct vm_area_struct *);
> -int anon_vma_clone(struct vm_area_struct *, struct vm_area_struct *);
> -int anon_vma_fork(struct vm_area_struct *, struct vm_area_struct *);
> -
> -static inline int anon_vma_prepare(struct vm_area_struct *vma)
> -{
> -       if (likely(vma->anon_vma))
> -               return 0;
> -
> -       return __anon_vma_prepare(vma);
> -}
> -
> -struct anon_vma *folio_get_anon_vma(const struct folio *folio);
>
>  #ifdef CONFIG_MM_ID
>  static __always_inline void folio_lock_large_mapcount(struct folio *folio)
> diff --git a/mm/internal.h b/mm/internal.h
> index e430da900430..469d4ef1ccc5 100644
> --- a/mm/internal.h
> +++ b/mm/internal.h
> @@ -199,6 +199,64 @@ static inline void vma_close(struct vm_area_struct *vma)
>
>  #ifdef CONFIG_MMU
>
> +static inline void get_anon_vma(struct anon_vma *anon_vma)
> +{
> +       atomic_inc(&anon_vma->refcount);
> +}
> +
> +void __put_anon_vma(struct anon_vma *anon_vma);
> +
> +static inline void put_anon_vma(struct anon_vma *anon_vma)
> +{
> +       if (atomic_dec_and_test(&anon_vma->refcount))
> +               __put_anon_vma(anon_vma);
> +}
> +
> +static inline void anon_vma_lock_write(struct anon_vma *anon_vma)
> +{
> +       down_write(&anon_vma->root->rwsem);
> +}
> +
> +static inline int anon_vma_trylock_write(struct anon_vma *anon_vma)
> +{
> +       return down_write_trylock(&anon_vma->root->rwsem);
> +}
> +
> +static inline void anon_vma_unlock_write(struct anon_vma *anon_vma)
> +{
> +       up_write(&anon_vma->root->rwsem);
> +}
> +
> +static inline void anon_vma_lock_read(struct anon_vma *anon_vma)
> +{
> +       down_read(&anon_vma->root->rwsem);
> +}
> +
> +static inline int anon_vma_trylock_read(struct anon_vma *anon_vma)
> +{
> +       return down_read_trylock(&anon_vma->root->rwsem);
> +}
> +
> +static inline void anon_vma_unlock_read(struct anon_vma *anon_vma)
> +{
> +       up_read(&anon_vma->root->rwsem);
> +}
> +
> +struct anon_vma *folio_get_anon_vma(const struct folio *folio);
> +
> +int anon_vma_clone(struct vm_area_struct *dst, struct vm_area_struct *src);
> +int anon_vma_fork(struct vm_area_struct *vma, struct vm_area_struct *pvma);
> +int  __anon_vma_prepare(struct vm_area_struct *vma);
> +void unlink_anon_vmas(struct vm_area_struct *vma);
> +
> +static inline int anon_vma_prepare(struct vm_area_struct *vma)
> +{
> +       if (likely(vma->anon_vma))
> +               return 0;
> +
> +       return __anon_vma_prepare(vma);
> +}
> +
>  /* Flags for folio_pte_batch(). */
>  typedef int __bitwise fpb_t;
>
> --
> 2.52.0
>