On Mon, Jul 29, 2024 at 02:12:15PM +0200, Mateusz Guzik wrote: > There needs to be a dev + ino replacement which retains the property > of being reliable between reboots and so on. Yes, that's exactly what filehandles provide. OTOH, dev + ino by itself does not provide this guarantee, as st_dev is not guaranteed to be constant across reboots because of things like async device discovery and enumeration. i.e. userspace has to do a bunch of work to determine the "st_dev" for a given filesystem actually refers to the same filesystem it did before the system restarted (e.g. via FS uuid checks). Filehandles already contain persistent filesystem identifiers, and so userspace doesn't have to do anything special to ensure that comparisons across reboots are valid. -Dave. -- Dave Chinner david@xxxxxxxxxxxxx
