Re: [PATCH v2 5/5] mm/khugepaged: Convert collapse_pte_mapped_thp() to use folios

[Vishal Moola]

 On Wed, Oct 18, 2023 at 01:32:13PM -0700, Vishal Moola (Oracle) wrote:
> This removes 2 calls to compound_head() and helps convert khugepaged to
> use folios throughout.
> 
> Previously, if the address passed to collapse_pte_mapped_thp()
> corresponded to a tail page, the scan would fail immediately. Using
> filemap_lock_folio() we can get the corresponding folio back and try to
> operate on the folio instead.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@xxxxxxxxx>

Hi Andrew, I've attached a fix patch addressing the syzbot issue.
It can be squashed into this patch, syzbot tested it on v2 already as
well.