Re: [RFC PATCH V4] iomap: add support to track dirty state of sub pages

[Matthew Wilcox]

On Fri, Aug 21, 2020 at 08:33:06PM +0800, Yu Kuai wrote:
> changes from v3:
>  - add IOMAP_STATE_ARRAY_SIZE
>  - replace set_bit / clear_bit with bitmap_set / bitmap_clear
>  - move iomap_set_page_dirty() out of 'iop->state_lock'
>  - merge iomap_set/clear_range_dirty() and iomap_iop_clear/clear_range_dirty()

I'm still working on the iomap parts of the THP series (fixing up
invalidatepage right now), but here are some of the relevant bits (patch
series to follow)