Re: [PATCH] mm: thp: Deny THP for guest_memfd and secretmem in file_thp_enabled()

["David Hildenbrand (Arm)" <david@kernel.org>]

On 2/21/26 05:37, Deepanshu Kartikey wrote:
> On Fri, Feb 13, 2026 at 2:36 PM David Hildenbrand (Arm)
> <david@kernel.org> wrote:
>>
> 
>>> For 6.12 stable backport:
>>>     - IS_ANON_FILE / S_ANON_INODE does not exist in 6.12, so use
>>>       mapping_inaccessible() || secretmem_mapping() in file_thp_enabled()
>>>       instead
>>
>> I think secretmem_mapping() is sufficient there given that guest_memfd
>> does not apply yet.
>>
>> But we can discuss the details about the backport once the upstream fix
>> is in.
>>
> 
> Subject: Re: [PATCH v2] mm: thp: deny THP for files on anonymous inodes
> 
> Hi David,

Hi!

> 
> The upstream fix is now in mm-unstable and linux-next. Should I send a
> backport for 6.12 stable?

Wait until it is in Linus' tree. As we CC stable, you should get a 
notification that applying the patch failed.

In reply to that mail, you can more easily send the backport.

> 
> Since IS_ANON_FILE / S_ANON_INODE does not exist in 6.12, I was
> planning to use secretmem_mapping() in file_thp_enabled() as you
> suggested. guest_memfd mmap is not present in 6.12 so only secretmem
> needs fixing there.
Makes sense. 19bbfe7b5fcc ("fs: add S_ANON_INODE") does not apply 
cleanly to to 6.12.

-- 
Cheers,

David