Re: [PATCH v4 2/3] mm: document locking restrictions for vm_operations_struct::close

From: Michal Hocko
Date: Thu Dec 09 2021 - 03:56:04 EST


On Wed 08-12-21 13:22:10, Suren Baghdasaryan wrote:
> Add comments for vm_operations_struct::close documenting locking
> requirements for this callback and its callers.
>
> Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>

Acked-by: Michal Hocko <mhocko@xxxxxxxx>

> ---
> include/linux/mm.h | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index a7e4a9e7d807..b9b88ba7564b 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -577,6 +577,10 @@ enum page_entry_size {
> */
> struct vm_operations_struct {
> void (*open)(struct vm_area_struct * area);
> + /**
> + * @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);
> /* Called any time before splitting to check if it's allowed */
> int (*may_split)(struct vm_area_struct *area, unsigned long addr);
> --
> 2.34.1.400.ga245620fadb-goog

--
Michal Hocko
SUSE Labs