On Thu 24-08-17 05:27:20, Christoph Hellwig wrote: > Just curious: how does IOMAP_F_NEEDDSYNC practically differ > from IOMAP_F_NEW? 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. Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR