On Thu, Mar 20, 2025 at 09:49:44AM +0000, John Garry wrote: >>> offset_fsb does not change, and logically cmap.br_startoff == end_fsb >>> already, right? >> >> Afte unlocking and relocking the ilock the extent layout could have >> changed. > > ok, understood. Maybe a comment will help understanding that. Sure. As said this was just intended as draft code. Maybe factoring out a helper or two would also be useful, although I couldn't think of a really obvious one.