On Wed, Feb 03, 2021 at 03:41:56PM +0300, Pavel Tikhomirov wrote: > Currently there is no way to differentiate the file with alive owner > from the file with dead owner but pid of the owner reused. That's why > CRIU can't actually know if it needs to restore file owner or not, > because if it restores owner but actual owner was dead, this can > introduce unexpected signals to the "false"-owner (which reused the > pid). Hi! Thanks for the patch. You know I manage to forget the fowner internals. Could you please enlighten me -- when owner is set with some pid we do f_setown_ex __f_setown f_modown filp->f_owner.pid = get_pid(pid); Thus pid get refcount incremented. Then the owner exits but refcounter should be still up and running and pid should not be reused, no? Or I miss something obvious? The patch itself looks ok on a first glance.