On Wed, Sep 3, 2025 at 11:00 PM Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: > > On Wed, Sep 03, 2025 at 01:16:59PM -0700, Darrick J. Wong wrote: > > On Fri, Aug 29, 2025 at 04:56:12PM -0700, Joanne Koong wrote: > > > Move the iomap_readpage_iter() async bio read logic into a separate > > > helper function. This is needed to make iomap read/readahead more > > > generically usable, especially for filesystems that do not require > > > CONFIG_BLOCK. > > > > > > Rename iomap_read_folio_range() to iomap_read_folio_range_sync() to > > > diferentiate between the synchronous and asynchronous bio folio read > > > calls. > > > > Hrmm. Readahead is asynchronous, whereas reading in data as part of an > > unaligned write to a file must be synchronous. How about naming it > > iomap_readahead_folio_range() ? > > > > Oh wait, iomap_read_folio also calls iomap_readpage_iter, which uses the > > readahead paths to fill out a folio, but then waits for the folio lock > > to drop, which effectively makes it ... a synchronous user of > > asynchronous code. > > > > Bleh, naming is hard. Though the code splitting seems fine... > > Maybe we can look at it from a different angle - the code split out > isn't really about async vs sync, but about actually using a bio > to read data from a block device. Which is also kinda important > for what Joanne is trying to do. So I'd encode that in the name, > e.g. iomap_read_folio_range_bio to mimici the naming used for > iomap_dio_bio_iter in the direct I/O code. > I think the issue is that the iomap_read_folio_range() function used for buffered writes also uses a bio, so there still needs to be some way to differentiate between the two. Maybe making the async one the default "iomap_read_folio_range" and then the synchronous one "iomap_read_folio_range_sync"?
