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

[David Hildenbrand (Red Hat)]

On 11/23/25 11:27, Mike Rapoport wrote:
> From: "Mike Rapoport (Microsoft)" <rppt@xxxxxxxxxx>
>
> 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_pagecache_folio()

get_shared_folio()

Given that the helper now no longer receives a VMA, I assume we can just 
really call it get_folio() and the "shared" part would be implicit. 
(from the inode)

> method to 'struct vm_operations_struct' that will return a folio if it
> exists in the VMA's pagecache at given pgoff.
>
> Implement get_pagecache_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@xxxxxxxxxx>
> ---

Nothing else jumped at me :)

--
Cheers

David