bound the amount of outstanding IO we need to do to flush the journal.
At the same time, we don't want to necessarily do it inline in case we
might be able to combine several IOs on the same object close together
-in time. Thus, in FileStore::_write, we queue the fd for asyncronous
+in time. Thus, in FileStore::_write, we queue the fd for asynchronous
flushing and block in FileStore::_do_op if we have exceeded any hard
limits until the background flusher catches up.
filestore_queue_high_delay_multiple
filestore_queue_max_delay_multiple
-While each throttle is at less than low_threshhold of the max,
+While each throttle is at less than low_threshold of the max,
no delay happens. Between low and high, the throttle will
inject a per-op delay (per op or byte) ramping from 0 at low to
high_delay_multiple/expected_throughput at high. From high to