On 2025-04-17 17:28:20 [+0200], Christian Brauner wrote: > > So if there's some userspace process with a broken NFS server and it > > does umount(MNT_DETACH) it will end up hanging every other > > umount(MNT_DETACH) on the system because the dealyed_mntput_work > > workqueue (to my understanding) cannot make progress. > > Ok, "to my understanding" has been updated after going back and reading > the delayed work code. Luckily it's not as bad as I thought it is > because it's queued on system_wq which is multi-threaded so it's at > least not causing everyone with MNT_DETACH to get stuck. I'm still > skeptical how safe this all is. I would (again) throw system_unbound_wq into the game because the former will remain on the CPU on which has been enqueued (if speaking about multi threading). Sebastian
