Re: [PATCH 03/15] mm: document vm_operations_struct->open the same as close()

On Thu, Mar 12, 2026 at 1:27 PM Lorenzo Stoakes (Oracle) <[email protected]> wrote:
>
> Describe when the operation is invoked and the context in which it is
> invoked, matching the description already added for vm_op->close().
>
> While we're here, update all outdated references to an 'area' field for
> VMAs to the more consistent 'vma'.
>
> Signed-off-by: Lorenzo Stoakes (Oracle) <[email protected]>
> ---
>  include/linux/mm.h | 15 ++++++++++-----
>  1 file changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index cc5960a84382..12a0b4c63736 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -748,15 +748,20 @@ struct vm_uffd_ops;
>   * to the functions called when a no-page or a wp-page exception occurs.
>   */
>  struct vm_operations_struct {
> -       void (*open)(struct vm_area_struct * area);
> +       /**
> +        * @open: Called when a VMA is remapped or split. Not called upon first
> +        * mapping a VMA.

It's also called from dup_mmap() which is part of forking.

> +        * Context: User context.  May sleep.  Caller holds mmap_lock.
> +        */
> +       void (*open)(struct vm_area_struct *vma);
>         /**
>          * @close: Called when the VMA is being removed from the MM.
>          * Context: User context.  May sleep.  Caller holds mmap_lock.
>          */
> -       void (*close)(struct vm_area_struct * area);
> +       void (*close)(struct vm_area_struct *vma);
>         /* Called any time before splitting to check if it's allowed */
> -       int (*may_split)(struct vm_area_struct *area, unsigned long addr);
> -       int (*mremap)(struct vm_area_struct *area);
> +       int (*may_split)(struct vm_area_struct *vma, unsigned long addr);
> +       int (*mremap)(struct vm_area_struct *vma);
>         /*
>          * Called by mprotect() to make driver-specific permission
>          * checks before mprotect() is finalised.   The VMA must not
> @@ -768,7 +773,7 @@ struct vm_operations_struct {
>         vm_fault_t (*huge_fault)(struct vm_fault *vmf, unsigned int order);
>         vm_fault_t (*map_pages)(struct vm_fault *vmf,
>                         pgoff_t start_pgoff, pgoff_t end_pgoff);
> -       unsigned long (*pagesize)(struct vm_area_struct * area);
> +       unsigned long (*pagesize)(struct vm_area_struct *vma);
>
>         /* notification that a previously read-only page is about to become
>          * writable, if an error is returned it will cause a SIGBUS */
> --
> 2.53.0
>