sunrpc: don't call sleeping functions from the notifier block callbacks

The inet6addr_chain is an atomic notifier chain, so we can't call
anything that might sleep (like lock_sock)... instead of closing the
socket from svc_age_temp_xprts_now (which is called by the notifier
function), just have the rpc service threads do it instead.

Cc: stable@vger.kernel.org
Fixes: c3d4879e01 "sunrpc: Add a function to close..."
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

include/linux/sunrpc/svc_xprt.h

@@ -66,6 +66,7 @@ struct svc_xprt {
 #define XPT_LISTENER	10		/* listening endpoint */
 #define XPT_CACHE_AUTH	11		/* cache auth info */
 #define XPT_LOCAL	12		/* connection from loopback interface */
+#define XPT_KILL_TEMP   13		/* call xpo_kill_temp_xprt before closing */
 
 	struct svc_serv		*xpt_server;	/* service for transport */
 	atomic_t    	    	xpt_reserved;	/* space on outq that is rsvd */

net/sunrpc/svc_xprt.c

@@ -799,6 +799,8 @@ static int svc_handle_xprt(struct svc_rqst *rqstp, struct svc_xprt *xprt)
 
 	if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) {
 		dprintk("svc_recv: found XPT_CLOSE\n");
+		if (test_and_clear_bit(XPT_KILL_TEMP, &xprt->xpt_flags))
+			xprt->xpt_ops->xpo_kill_temp_xprt(xprt);
 		svc_delete_xprt(xprt);
 		/* Leave XPT_BUSY set on the dead xprt: */
 		goto out;
@@ -1020,9 +1022,11 @@ void svc_age_temp_xprts_now(struct svc_serv *serv, struct sockaddr *server_addr)
 		le = to_be_closed.next;
 		list_del_init(le);
 		xprt = list_entry(le, struct svc_xprt, xpt_list);
-		dprintk("svc_age_temp_xprts_now: closing %p\n", xprt);
+		set_bit(XPT_CLOSE, &xprt->xpt_flags);
-		xprt->xpt_ops->xpo_kill_temp_xprt(xprt);
+		set_bit(XPT_KILL_TEMP, &xprt->xpt_flags);
-		svc_close_xprt(xprt);
+		dprintk("svc_age_temp_xprts_now: queuing xprt %p for closing\n",
+				xprt);
+		svc_xprt_enqueue(xprt);
 	}
 }
 EXPORT_SYMBOL_GPL(svc_age_temp_xprts_now);