SUNRPC search xprt switch for sockaddr

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

4 files changed, 42 insertions, 1 deletions

diff --git a/include/linux/sunrpc/clnt.h b/include/linux/sunrpc/clnt.h
index b069d6e2c3d6..35cc539e2921 100644
--- a/include/linux/sunrpc/clnt.h
+++ b/include/linux/sunrpc/clnt.h
@@ -202,5 +202,7 @@ 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 *);
+bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
+                        const struct sockaddr *sap);
 #endif /* __KERNEL__ */
 #endif /* _LINUX_SUNRPC_CLNT_H */
diff --git a/include/linux/sunrpc/xprtmultipath.h b/include/linux/sunrpc/xprtmultipath.h
index 5a9acffa41be..507418c1c69e 100644
--- a/include/linux/sunrpc/xprtmultipath.h
+++ b/include/linux/sunrpc/xprtmultipath.h
@@ -66,4 +66,6 @@ extern struct rpc_xprt *xprt_iter_xprt(struct rpc_xprt_iter *xpi);
 extern struct rpc_xprt *xprt_iter_get_xprt(struct rpc_xprt_iter *xpi);
 extern struct rpc_xprt *xprt_iter_get_next(struct rpc_xprt_iter *xpi);
 
+extern bool rpc_xprt_switch_has_addr(struct rpc_xprt_switch *xps,
+                const struct sockaddr *sap);
 #endif
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 43ec46547dc9..8d68efd2026f 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -2708,6 +2708,21 @@ void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
 }
 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_add_xprt);
 
+bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
+                                   const struct sockaddr *sap)
+{
+        struct rpc_xprt_switch *xps;
+        bool ret;
+
+        xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
+
+        rcu_read_lock();
+        ret = rpc_xprt_switch_has_addr(xps, sap);
+        rcu_read_unlock();
+        return ret;
+}
+EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_has_addr);
+
 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 static void rpc_show_header(void)
 {
diff --git a/net/sunrpc/xprtmultipath.c b/net/sunrpc/xprtmultipath.c
index 66c9d63f4797..ae92a9e9ba52 100644
--- a/net/sunrpc/xprtmultipath.c
+++ b/net/sunrpc/xprtmultipath.c
@@ -15,6 +15,7 @@
 #include <asm/cmpxchg.h>
 #include <linux/spinlock.h>
 #include <linux/sunrpc/xprt.h>
+#include <linux/sunrpc/addr.h>
 #include <linux/sunrpc/xprtmultipath.h>
 
 typedef struct rpc_xprt *(*xprt_switch_find_xprt_t)(struct list_head *head,
@@ -49,7 +50,8 @@ void rpc_xprt_switch_add_xprt(struct rpc_xprt_switch *xps,
         if (xprt == NULL)
                 return;
         spin_lock(&xps->xps_lock);
-        if (xps->xps_net == xprt->xprt_net || xps->xps_net == NULL)
+        if ((xps->xps_net == xprt->xprt_net || xps->xps_net == NULL) &&
+            !rpc_xprt_switch_has_addr(xps, (struct sockaddr *)&xprt->addr))
                 xprt_switch_add_xprt_locked(xps, xprt);
         spin_unlock(&xps->xps_lock);
 }
@@ -232,6 +234,26 @@ struct rpc_xprt *xprt_iter_current_entry(struct rpc_xprt_iter *xpi)
         return xprt_switch_find_current_entry(head, xpi->xpi_cursor);
 }
 
+bool rpc_xprt_switch_has_addr(struct rpc_xprt_switch *xps,
+                              const struct sockaddr *sap)
+{
+        struct list_head *head;
+        struct rpc_xprt *pos;
+
+        if (xps == NULL || sap == NULL)
+                return false;
+
+        head = &xps->xps_xprt_list;
+        list_for_each_entry_rcu(pos, head, xprt_switch) {
+                if (rpc_cmp_addr_port(sap, (struct sockaddr *)&pos->addr)) {
+                        pr_info("RPC:   addr %s already in xprt switch\n",
+                                pos->address_strings[RPC_DISPLAY_ADDR]);
+                        return true;
+                }
+        }
+        return false;
+}
+
 static
 struct rpc_xprt *xprt_switch_find_next_entry(struct list_head *head,
                 const struct rpc_xprt *cur)