Grant
~~~~~
[[grant]]

A grant value is part of a client's state for a given target. It
provides an upper bound to the amount of dirty cache data the client
will allow that is destined for the target. The value is established
by agreement between the server and the client and represents a
guarantee by the server that the target storage has enough free space
for at least the amount of granted dirty data. The client can ask for
additional grant with each write RPC, which the server may provide
depending on how much available (ungranted and unallocated) space the
target has.