On Mon, Sep 30, 2019 at 11:04:55AM +0200, Stefan Metzmacher wrote: > Currently there seems to be a problem when an RDMA listener or connection > is active on an ib_device. > > 'rmmod rdma_rxe' (the same for 'siw' and most likely all > others) just hangs like this until shutdown the listeners and > connections: > > [<0>] remove_client_context+0x97/0xe0 [ib_core] > [<0>] disable_device+0x90/0x120 [ib_core] > [<0>] __ib_unregister_device+0x41/0xa0 [ib_core] > [<0>] ib_unregister_driver+0xbb/0x100 [ib_core] > [<0>] rxe_module_exit+0x1a/0x8aa [rdma_rxe] > [<0>] __x64_sys_delete_module+0x147/0x290 > [<0>] do_syscall_64+0x5a/0x130 > [<0>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > The following would be expected: > > rmmod: ERROR: Module rdma_rxe is in use > > And this change provides that. > > Once all add listeners and connections are gone > the module can be removed again. > > Signed-off-by: Stefan Metzmacher <metze@xxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx > --- > drivers/infiniband/core/cma.c | 2 ++ > 1 file changed, 2 insertions(+) How do you even get here? Are you using in-kernel modules to access rxe? Drivers are supposed to declare a DEVICE_FATAL error when their module is removed and then progress toward cleaning up. It would seem this is missing in rxe. Globally blocking module unload would break the existing dis-associate flows, and blocking until listeners are removed seems like all rdma drivers will instantly become permanetly blocked when things like SRP or IPoIB CM mode are running? I think the proper thing is to fix rxe (and probably siw) to signal the DEVICE_FATAL so the CMA listeners can cleanly disconnect Jason
