On Thu, Aug 24, 2017 at 02:34:51PM +0200, Jan Kara wrote: > In a subtle but important way ;). The main difference is that if the extent > has been already allocated by previous write, but the changing transaction > is not yet committed, we will return IOMAP_F_NEEDDSYNC but not IOMAP_F_NEW. Ok. How about a IOMAP_F_DIRTY flag and a better explanation?