On Fri, Nov 25, 2022 at 10:17:28PM +0000, Al Viro wrote: > The bottom line: > * teach your ufs_put_page() to accept any address within the page > * flip the ways you return page and address in ufs_get_page() > * use offset_in_page(addr) instead of these addr - page_address(page) > and you'll get a much smaller patch, with a lot less noise in it. > What's more, offset_in_page() part can be carved out into a separate > commit - it's valid on its own, and it makes both halves easier to > follow. > > AFAICS, similar observations apply in your sysvfs patch; the point about > calling conventions for ufs_get_page() definitely applies there, and > stronger than for ufs - those casts are eye-watering... As the matter of fact, I'd probably split it into 3 steps: 1) switch the calling conventions of ufs_get_page() - callers follow it with something like kaddr = page_address(page); and that change makes sense on its own. Isolated and easy to follow. 2) offset_in_page() changes. Again, separate, stands on its own and is easy to follow. 3) kmap_local() switch itself - pass address to ufs_put_page(), etc. Considerably smaller and less cluttered than your current variant.
