RPC/RDMA: harden connection logic against missing/late rdma_cm upcalls.

Add defensive timeouts to wait_for_completion() calls in RDMA
address resolution, and make them interruptible. Fix the timeout
units to milliseconds (formerly jiffies) and move to private header.

Signed-off-by: Tom Talpey <talpey@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

2 files changed, 10 insertions, 4 deletions

diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index a63d0c0ec017..f46fb93f421b 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -284,6 +284,7 @@ rpcrdma_conn_upcall(struct rdma_cm_id *id, struct rdma_cm_event *event)
         switch (event->event) {
         case RDMA_CM_EVENT_ADDR_RESOLVED:
         case RDMA_CM_EVENT_ROUTE_RESOLVED:
+                ia->ri_async_rc = 0;
                 complete(&ia->ri_done);
                 break;
         case RDMA_CM_EVENT_ADDR_ERROR:
@@ -363,26 +364,28 @@ rpcrdma_create_id(struct rpcrdma_xprt *xprt,
                 return id;
         }
 
-        ia->ri_async_rc = 0;
+        ia->ri_async_rc = -ETIMEDOUT;
         rc = rdma_resolve_addr(id, NULL, addr, RDMA_RESOLVE_TIMEOUT);
         if (rc) {
                 dprintk("RPC:       %s: rdma_resolve_addr() failed %i\n",
                         __func__, rc);
                 goto out;
         }
-        wait_for_completion(&ia->ri_done);
+        wait_for_completion_interruptible_timeout(&ia->ri_done,
+                                msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT) + 1);
         rc = ia->ri_async_rc;
         if (rc)
                 goto out;
 
-        ia->ri_async_rc = 0;
+        ia->ri_async_rc = -ETIMEDOUT;
         rc = rdma_resolve_route(id, RDMA_RESOLVE_TIMEOUT);
         if (rc) {
                 dprintk("RPC:       %s: rdma_resolve_route() failed %i\n",
                         __func__, rc);
                 goto out;
         }
-        wait_for_completion(&ia->ri_done);
+        wait_for_completion_interruptible_timeout(&ia->ri_done,
+                                msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT) + 1);
         rc = ia->ri_async_rc;
         if (rc)
                 goto out;
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index fde6499a53b2..c7a7eba991bc 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -51,6 +51,9 @@
 #include <linux/sunrpc/rpc_rdma.h>      /* RPC/RDMA protocol */
 #include <linux/sunrpc/xprtrdma.h>      /* xprt parameters */
 
+#define RDMA_RESOLVE_TIMEOUT    (5000)  /* 5 seconds */
+#define RDMA_CONNECT_RETRY_MAX  (2)     /* retries if no listener backlog */
+
 /*
  * Interface Adapter -- one per transport instance
  */