This patch is believed to fix a problem in the kernel rpc for

non-interruptible NFS mounts, where a kernel thread will seem
to be stuck sleeping on "rpccon". The msleep() in clnt_vc_create()
that was waiting to a TCP connect to complete would return ERESTART,
since PCATCH was specified. Then the tsleep() in clnt_reconnect_call()
would sleep for 1 second and then try again and again and...
The patch changes the msleep() in clnt_vc_create() so it only sets
the PCATCH flag for interruptible cases.

Tested by:	pho
Reviewed by:	jhb
MFC after:	2 weeks

4 files changed, 11 insertions, 6 deletions

diff --git a/sys/rpc/clnt.h b/sys/rpc/clnt.h
index 74d5813..e4da36a 100644
--- a/sys/rpc/clnt.h
+++ b/sys/rpc/clnt.h
@@ -433,10 +433,11 @@ extern CLIENT *clnt_dg_create(struct socket *so,
  *	rpcvers_t vers;				-- version number
  *	size_t sendsz;				-- buffer recv size
  *	size_t recvsz;				-- buffer send size
+ *	int intrflag;				-- is it interruptible
  */
 extern CLIENT *clnt_vc_create(struct socket *so,
     struct sockaddr *svcaddr, rpcprog_t program, rpcvers_t version,
-    size_t sendsz, size_t recvsz);
+    size_t sendsz, size_t recvsz, int intrflag);
 
 /*
  *	struct netconfig *nconf;		-- network type
diff --git a/sys/rpc/clnt_rc.c b/sys/rpc/clnt_rc.c
index 24fc09a..e263278 100644
--- a/sys/rpc/clnt_rc.c
+++ b/sys/rpc/clnt_rc.c
@@ -195,7 +195,7 @@ clnt_reconnect_connect(CLIENT *cl)
 	else
 		newclient = clnt_vc_create(so,
 		    (struct sockaddr *) &rc->rc_addr, rc->rc_prog, rc->rc_vers,
-		    rc->rc_sendsz, rc->rc_recvsz);
+		    rc->rc_sendsz, rc->rc_recvsz, rc->rc_intr);
 	td->td_ucred = oldcred;
 
 	if (!newclient) {
diff --git a/sys/rpc/clnt_vc.c b/sys/rpc/clnt_vc.c
index b94526d..ea3b7d1 100644
--- a/sys/rpc/clnt_vc.c
+++ b/sys/rpc/clnt_vc.c
@@ -168,7 +168,8 @@ clnt_vc_create(
 	const rpcprog_t prog,		/* program number */
 	const rpcvers_t vers,		/* version number */
 	size_t sendsz,			/* buffer recv size */
-	size_t recvsz)			/* buffer send size */
+	size_t recvsz,			/* buffer send size */
+	int intrflag)			/* interruptible */
 {
 	CLIENT *cl;			/* client handle */
 	struct ct_data *ct = NULL;	/* client handle */
@@ -177,7 +178,7 @@ clnt_vc_create(
 	static uint32_t disrupt;
 	struct __rpc_sockinfo si;
 	XDR xdrs;
-	int error, interrupted, one = 1;
+	int error, interrupted, one = 1, sleep_flag;
 	struct sockopt sopt;
 
 	if (disrupt == 0)
@@ -196,10 +197,13 @@ clnt_vc_create(
 		error = soconnect(so, raddr, curthread);
 		SOCK_LOCK(so);
 		interrupted = 0;
+		sleep_flag = PSOCK;
+		if (intrflag != 0)
+			sleep_flag |= (PCATCH | PBDRY);
 		while ((so->so_state & SS_ISCONNECTING)
 		    && so->so_error == 0) {
 			error = msleep(&so->so_timeo, SOCK_MTX(so),
-			    PSOCK | PCATCH | PBDRY, "connec", 0);
+			    sleep_flag, "connec", 0);
 			if (error) {
 				if (error == EINTR || error == ERESTART)
 					interrupted = 1;
diff --git a/sys/rpc/rpcb_clnt.c b/sys/rpc/rpcb_clnt.c
index 9b23fb3..d484df3 100644
--- a/sys/rpc/rpcb_clnt.c
+++ b/sys/rpc/rpcb_clnt.c
@@ -477,7 +477,7 @@ local_rpcb()
 
 	tsize = __rpc_get_t_size(AF_LOCAL, 0, 0);
 	client = clnt_vc_create(so, (struct sockaddr *)&sun, (rpcprog_t)RPCBPROG,
-	    (rpcvers_t)RPCBVERS, tsize, tsize);
+	    (rpcvers_t)RPCBVERS, tsize, tsize, 1);
 
 	if (client != NULL) {
 		/* Mark the socket to be closed in destructor */