On 02/07/2020 09:59, Hannes Reinecke wrote: > That's one of the best-kept secrets in the block layer: > > op_is_write() > > The assumption is that every request with a REQ_OP which has the lowest > bit set is a write. > And quite a lot of accounting the the block layer revolves around that. > So we'll need to keep it. > > ... and we probably should document it somewhere. I personally find this very obvious: static inline bool op_is_write(unsigned int op) { return (op & 1); }