In particular, the kernel RPC layer used by the NFS client never
invokes pru_rcvd since it always reads data from the socket upcall
via MSG_SOCALLBCK which avoids calling pru_rcvd. As a result, on an
NFS client connection managed by t4_tom, RX credits were never
returned to the TOE connection to open the TCP window resulting in
connection hangs.
To fix, expand the set of conditions in do_rx_data where RX credits
are returned to match those in t4_rcvd_locked by calling the function
directly.
Reviewed by: np
Sponsored by: Chelsio Communications
Differential Revision: https://reviews.freebsd.org/D41688
(cherry picked from commit dcfddc8dc091e7688abc8488a0307eba425fa7a2)
bd8cecc466