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>

diff --git a/include/linux/sunrpc/xprtrdma.h b/include/linux/sunrpc/xprtrdma.h
index 55a5d92ca1e28f22a47413780ce5a545e38cec54..54a379c9e8ebd3709ed684d05f871322c12648a4 100644 (file)
--- a/include/linux/sunrpc/xprtrdma.h
+++ b/include/linux/sunrpc/xprtrdma.h
@@ -66,9 +66,6 @@
 
 #define RPCRDMA_INLINE_PAD_THRESH  (512)/* payload threshold to pad (bytes) */
 
-#define RDMA_RESOLVE_TIMEOUT   (5*HZ)  /* TBD 5 seconds */
-#define RDMA_CONNECT_RETRY_MAX (2)     /* retries if no listener backlog */
-
 /* memory registration strategies */
 #define RPCRDMA_PERSISTENT_REGISTRATION (1)
 

diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index a63d0c0ec0175f8a26d2e8ab72318be26df9ee06..f46fb93f421b3e723e011a111e456c09b6c1fe70 100644 (file)
--- 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 fde6499a53b2bc4efb590dddefa90f1af8cde2b7..c7a7eba991bc11e592aa541ba39c29fe22eaa9f2 100644 (file)
--- 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
  */