On Wed, Aug 13, 2025 at 05:21:22PM +0800, Nanzhe Zhao wrote: > * **Why extends iomap** > * F2FS stores its flags in the folio's private field, > which conflicts with iomap_folio_state. > * To resolve this, we designed f2fs_iomap_folio_state, > compatible with iomap_folio_state's layout while extending > its flexible state array for F2FS private flags. > * We store a magic number in read_bytes_pending to distinguish > whether a folio uses the original or F2FS's iomap_folio_state. > It's chosen because it remains 0 after readahead completes. That's pretty ugly. What additionals flags do you need? We should try to figure out if there is a sensible way to support the needs with a single codebase and data structure if that the requirements are sensible.