Re: [PATCH v2 2/5] userfaultfd, shmem: use a VMA callback to handle UFFDIO_CONTINUE

David Hildenbrand (Red Hat)
2025-11-26T10:21:33Z

On 11/25/25 19:38, Mike Rapoport wrote:
> From: "Mike Rapoport (Microsoft)" <rppt@kernel.org>
>
> When userspace resolves a page fault in a shmem VMA with UFFDIO_CONTINUE
> it needs to get a folio that already exists in the pagecache backing
> that VMA.
>
> Instead of using shmem_get_folio() for that, add a get_folio() method to
> 'struct vm_operations_struct' that will return a folio if it exists in
> the VMA's pagecache at given pgoff.
>
> Implement get_folio() method for shmem and slightly refactor
> userfaultfd's mfill_atomic() and mfill_atomic_pte_continue() to support
> this new API.
>
> Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> ---

Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>

--
Cheers

David