> > Thanks. This wasn't obvious to me from the current code. I'll add a > > comment in the next version. > > The crucial question is now, is it sufficient to call > blk_mq_quiesce_queue_nowait() under the mutex, or does the call to > blk_mq_wait_quiesce_done() have to be under the mutex, too? > The latter would actually kill off our attempt to fix the delay > in fc_remote_port_delete() that was caused by repeated > synchronize_rcu() calls. > > But if I understand you correctly, moving the wait out of the mutex > should be ok. I'll update the series accordingly. I can't think of a reason we'd want to lock over the wait, but Bart knows this code way better than I do.