On Fri, Apr 21, 2023 at 08:01:09AM +1000, NeilBrown wrote: > On Fri, 21 Apr 2023, Al Viro wrote: > > 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? > > > > 1/ set a "forced-unmount" flag on the vfs_mount which causes any syscall > that uses the vfsmount (whether from an fd, or found in a path walk, > or elsewhere), except for close(), to abort with an error; > 2/ call ->umount_begin passing in the vfs_mount. The fs can abort any > outstanding transaction on any fd from that vfs_mount. How the hell would you recognize those?
