tree 320f7686025dd43b0470f75ac44ef37dc5eb090c
parent b54054ca5590f59469437fc4a78a978edcb01c31
author Chuck Lever <chuck.lever@oracle.com> 1467222815 -0400
committer Anna Schumaker <Anna.Schumaker@Netapp.com> 1468266643 -0400

xprtrdma: Reply buffer exhaustion can be catastrophic

Not having an rpcrdma_rep at call_allocate time can be a problem.
It means that send_request can't post a receive buffer to catch
the RPC's reply. Possible consequences are RPC timeouts or even
transport deadlock.

Instead of allowing an RPC to proceed if an rpcrdma_rep is
not available, return NULL to force call_allocate to wait and
try again.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>