On Tue, Apr 18, 2023 at 07:26:34AM +1000, NeilBrown wrote: > MNT_FORCE is, I think, a good idea and a needed functionality that has > never been implemented well. > MNT_FORCE causes nfs_umount_begin to be called as you noted, which > aborts all pending RPCs on that filesystem. Suppose it happens to be mounted in another namespace as well. Or bound at different mountpoint, for that matter. What should MNT_FORCE do?