On Tue, Jun 18, 2024 at 06:05:33PM +1200, Barry Song wrote: > Yes, that was exactly what I missed. I then figured it out, reproduced > the issue, > and discovered that the root cause was unrelated to large folios. It > was actually > due to a batched bio plugging optimization from 2022. You can find the new patch > here: > > https://lore.kernel.org/linux-mm/20240617220135.43563-1-21cnbao@xxxxxxxxx/ I don't really see any point in keeping the VM_BUG_ON. The underlying direct I/O code doesn't really care about the size at all.