On Mon, Jan 22, 2024 at 05:26:00PM +0000, Ryan Roberts wrote: > On 22/01/2024 17:20, Matthew Wilcox wrote: > > On Mon, Jan 22, 2024 at 06:01:58PM +0100, David Hildenbrand wrote: > >>> And folio_mark_dirty() is doing more than just setting teh PG_dirty bit. In my > >>> equivalent change, as part of the contpte series, I've swapped set_page_dirty() > >>> for folio_mark_dirty(). > >> > >> Good catch, that should be folio_mark_dirty(). Let me send a fixup. > >> > >> (the difference in naming for both functions really is bad) > > > > It really is, and I don't know what to do about it. > > > > We need a function that literally just sets the flag. For every other > > flag, that's folio_set_FLAG. We can't use __folio_set_flag because that > > means "set the flag non-atomically". > > > > We need a function that does all of the work involved with tracking > > dirty folios. I chose folio_mark_dirty() to align with > > folio_mark_uptodate() (ie mark is not just 'set" but also "do some extra > > work"). > > > > But because we're converting from set_page_dirty(), the OBVIOUS rename > > is to folio_set_dirty(), which is WRONG. > > > > So we're in the part of the design space where the consistent naming and > > the-obvious-thing-to-do-is-wrong are in collision, and I do not have a > > good answer. > > > > Maybe we can call the first function _folio_set_dirty(), and we don't > > have a folio_set_dirty() at all? We don't have a folio_set_uptodate(), > > so there's some precedent there. > > Is there anything stopping us from renaming set_page_dirty() to > mark_page_dirty() (or page_mark_dirty())? For me the folio naming is consistent, > but the page names suck; presumably PageSetDirty() and set_page_dirty()... yuk. Well, laziness. There's about 150 places where we mention set_page_dirty() and all of them need to be converted to folio_mark_dirty(). I don't particularly like converting code twice; I get the impression it annoys people. The important thing is what does it look like when someone writes a new filesystem in 2030. I fear that they may get confused and call folio_set_dirty(), not realising that they should be calling folio_mark_dirty(). It doesn't help that btrfs have decided to introduce btrfs_folio_set_dirty(). I think MM people can afford to add a leading '_' to folio_set_dirty() so that's my current favourite option for fixing this mess.
