[RFC PATCH 3/3] fb_defio: do not use deprecated page->mapping, index fields

[David Hildenbrand]

On 08.01.25 18:32, Matthew Wilcox wrote:
> On Wed, Jan 08, 2025 at 04:18:42PM +0000, Lorenzo Stoakes wrote:
>> @@ -280,7 +269,10 @@ static void fb_deferred_io_work(struct work_struct *work)
>>   		struct folio *folio = page_folio(pageref->page);
>>   
>>   		folio_lock(folio);
>> -		folio_mkclean(folio);
>> +		rmap_wrprotect_file_page(fbdefio->mapping,
>> +					 pageref->offset >> PAGE_SHIFT,
>> +					 compound_nr(pageref->page),
>> +					 page_to_pfn(pageref->page));
>>   		folio_unlock(folio);
> 
> Why do we need to lock the folio?  (since this isn't necessarily a
> folio) 

Can you clarify the "since this isn't necessarily a folio" part ? Do you 
mean in the future, when we split "struct page" and "struct folio"?

Doing an rmap walk on something that won't be a folio is ... sounds odd 
(->wrong :) )

-- 
Cheers,

David / dhildenb