On Thu, Nov 14, 2024 at 08:25:18AM -0700, Jens Axboe wrote: > + if (iocb->ki_flags & IOCB_UNCACHED) > + iter.flags |= IOMAP_UNCACHED; > > - while ((ret = iomap_iter(&iter, ops)) > 0) > + while ((ret = iomap_iter(&iter, ops)) > 0) { > + if (iocb->ki_flags & IOCB_UNCACHED) > + iter.iomap.flags |= IOMAP_F_UNCACHED; iomap.flags and the IOMAP_F_* namespace is used to communicate flags from the file system to the iomap core, so this looks wrong. > size_t poff = offset_in_folio(folio, pos); > int error; > > + if (folio_test_uncached(folio)) > + wpc->iomap.flags |= IOMAP_F_UNCACHED; I guess this is what actually makes it work. Note that with the iomap zoned series I posted yesteday things change a bit here in that the flags in the wpc are decouple from the iomap flags, and this would now become a wpc only flag as it isn't really a fs to iomap cummunication, but based on iomap / page cache state.