During testing of the pNFS client, it was observed that an RPC could get
stuck in sosend() for a very long time if the network connection to a DS
had failed. This is fixed by setting SO_SNDTIMEO on the TCP socket.
This is only done when CLSET_TIMEOUT is done and this is not done by any
use of the krpc currently in the source tree, so there should be no effect
on extant uses.
A future patch will use CLSET_TIMEOUT for TCP connections to DSs.
Reviewed by: kib
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D16293
7c83f50683