svn commit: r199293 - stable/8/sys/rpc

[Rick Macklem]

Author: rmacklem
Date: Sun Nov 15 19:26:06 2009
New Revision: 199293
URL: http://svn.freebsd.org/changeset/base/199293

Log:
  MFC: r199053
  Add a check for the connection being shut down to the krpc
  client just before queuing a request for the connection. The
  code already had a check for the connection being shut down
  while the request was queued, but not one for the shut down
  having been initiated by the server before the request was
  in the queue. This fixes some cases of problems w.r.t. reconnecting
  to a NFS server that drops inactive TCP connections.
  
  Tested by:	Olaf Seibert, Daniel Braniss
  Reviewed by:	dfr

Modified:
  stable/8/sys/rpc/clnt_vc.c
Directory Properties:
  stable/8/sys/   (props changed)
  stable/8/sys/amd64/include/xen/   (props changed)
  stable/8/sys/cddl/contrib/opensolaris/   (props changed)
  stable/8/sys/contrib/dev/acpica/   (props changed)
  stable/8/sys/contrib/pf/   (props changed)
  stable/8/sys/dev/xen/xenpci/   (props changed)
  stable/8/sys/netinet6/   (props changed)

Modified: stable/8/sys/rpc/clnt_vc.c
==============================================================================
--- stable/8/sys/rpc/clnt_vc.c	Sun Nov 15 18:31:57 2009	(r199292)
+++ stable/8/sys/rpc/clnt_vc.c	Sun Nov 15 19:26:06 2009	(r199293)
@@ -413,6 +413,22 @@ call_again:
 
 	cr->cr_xid = xid;
 	mtx_lock(&ct->ct_lock);
+	/*
+	 * Check to see if the other end has already started to close down
+	 * the connection. The upcall will have set ct_error.re_status
+	 * to RPC_CANTRECV if this is the case.
+	 * If the other end starts to close down the connection after this
+	 * point, it will be detected later when cr_error is checked,
+	 * since the request is in the ct_pending queue.
+	 */
+	if (ct->ct_error.re_status == RPC_CANTRECV) {
+		if (errp != &ct->ct_error) {
+			errp->re_errno = ct->ct_error.re_errno;
+			errp->re_status = RPC_CANTRECV;
+		}
+		stat = RPC_CANTRECV;
+		goto out;
+	}
 	TAILQ_INSERT_TAIL(&ct->ct_pending, cr, cr_link);
 	mtx_unlock(&ct->ct_lock);