SUNRPC create an rpc function that allows xprt removal from rpc_clnt

Expose a function that allows a removal of xprt from the rpc_clnt.

When called from NFS that's running a trunked transport then don't
decrement the active transport counter.
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

include/linux/sunrpc/clnt.h

@@ -240,6 +240,7 @@ const char *rpc_proc_name(const struct rpc_task *task);
 
 void rpc_clnt_xprt_switch_put(struct rpc_clnt *);
 void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *, struct rpc_xprt *);
+void rpc_clnt_xprt_switch_remove_xprt(struct rpc_clnt *, struct rpc_xprt *);
 bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
 			const struct sockaddr *sap);
 void rpc_clnt_xprt_set_online(struct rpc_clnt *clnt, struct rpc_xprt *xprt);

include/linux/sunrpc/xprtmultipath.h

@@ -55,7 +55,7 @@ extern void rpc_xprt_switch_set_roundrobin(struct rpc_xprt_switch *xps);
 extern void rpc_xprt_switch_add_xprt(struct rpc_xprt_switch *xps,
 		struct rpc_xprt *xprt);
 extern void rpc_xprt_switch_remove_xprt(struct rpc_xprt_switch *xps,
-		struct rpc_xprt *xprt);
+		struct rpc_xprt *xprt, bool offline);
 
 extern void xprt_iter_init(struct rpc_xprt_iter *xpi,
 		struct rpc_xprt_switch *xps);

net/sunrpc/clnt.c

@@ -2144,7 +2144,8 @@ call_connect_status(struct rpc_task *task)
 				xprt_release(task);
 				value = atomic_long_dec_return(&xprt->queuelen);
 				if (value == 0)
-					rpc_xprt_switch_remove_xprt(xps, saved);
+					rpc_xprt_switch_remove_xprt(xps, saved,
+								    true);
 				xprt_put(saved);
 				task->tk_xprt = NULL;
 				task->tk_action = call_start;
@@ -3118,6 +3119,19 @@ void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
 }
 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_add_xprt);
 
+void rpc_clnt_xprt_switch_remove_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
+{
+	struct rpc_xprt_switch *xps;
+
+	rcu_read_lock();
+	xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
+	rpc_xprt_switch_remove_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch),
+				    xprt, 0);
+	xps->xps_nunique_destaddr_xprts--;
+	rcu_read_unlock();
+}
+EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_remove_xprt);
+
 bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
 				   const struct sockaddr *sap)
 {

net/sunrpc/xprt.c

@@ -2182,5 +2182,5 @@ void xprt_delete_locked(struct rpc_xprt *xprt, struct rpc_xprt_switch *xps)
 
 	if (!xprt->sending.qlen && !xprt->pending.qlen &&
 	    !xprt->backlog.qlen && !atomic_long_read(&xprt->queuelen))
-		rpc_xprt_switch_remove_xprt(xps, xprt);
+		rpc_xprt_switch_remove_xprt(xps, xprt, true);
 }

net/sunrpc/xprtmultipath.c

@@ -62,11 +62,11 @@ void rpc_xprt_switch_add_xprt(struct rpc_xprt_switch *xps,
 }
 
 static void xprt_switch_remove_xprt_locked(struct rpc_xprt_switch *xps,
-		struct rpc_xprt *xprt)
+		struct rpc_xprt *xprt, bool offline)
 {
 	if (unlikely(xprt == NULL))
 		return;
-	if (!test_bit(XPRT_OFFLINE, &xprt->state))
+	if (!test_bit(XPRT_OFFLINE, &xprt->state) && offline)
 		xps->xps_nactive--;
 	xps->xps_nxprts--;
 	if (xps->xps_nxprts == 0)
@@ -79,14 +79,15 @@ static void xprt_switch_remove_xprt_locked(struct rpc_xprt_switch *xps,
  * rpc_xprt_switch_remove_xprt - Removes an rpc_xprt from a rpc_xprt_switch
  * @xps: pointer to struct rpc_xprt_switch
  * @xprt: pointer to struct rpc_xprt
+ * @offline: indicates if the xprt that's being removed is in an offline state
  *
  * Removes xprt from the list of struct rpc_xprt in xps.
  */
 void rpc_xprt_switch_remove_xprt(struct rpc_xprt_switch *xps,
-		struct rpc_xprt *xprt)
+		struct rpc_xprt *xprt, bool offline)
 {
 	spin_lock(&xps->xps_lock);
-	xprt_switch_remove_xprt_locked(xps, xprt);
+	xprt_switch_remove_xprt_locked(xps, xprt, offline);
 	spin_unlock(&xps->xps_lock);
 	xprt_put(xprt);
 }
@@ -155,7 +156,7 @@ static void xprt_switch_free_entries(struct rpc_xprt_switch *xps)
 
 		xprt = list_first_entry(&xps->xps_xprt_list,
 				struct rpc_xprt, xprt_switch);
-		xprt_switch_remove_xprt_locked(xps, xprt);
+		xprt_switch_remove_xprt_locked(xps, xprt, true);
 		spin_unlock(&xps->xps_lock);
 		xprt_put(xprt);
 		spin_lock(&xps->xps_lock);