xprtrdma: Refactor rpcrdma_ep_connect

I'm about to add another arm to

    if (ep->rep_connected != 0)

It will be cleaner to use a switch statement here. We'll be looking
for a couple of specific errnos, or "anything else," basically to
sort out the difference between a normal reconnect and recovery from
device removal.

This is a refactoring change only.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index 938fd9e6f308b4fb02fd52bf66f5d984558dd523..6479ad3fe69df74ea06a5bc4ac8d90a01b97f30d 100644 (file)
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -711,6 +711,57 @@ rpcrdma_ep_destroy(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
        ib_free_cq(ep->rep_attr.send_cq);
 }
 
+static int
+rpcrdma_ep_reconnect(struct rpcrdma_xprt *r_xprt, struct rpcrdma_ep *ep,
+                    struct rpcrdma_ia *ia)
+{
+       struct sockaddr *sap = (struct sockaddr *)&r_xprt->rx_data.addr;
+       struct rdma_cm_id *id, *old;
+       int err, rc;
+
+       dprintk("RPC:       %s: reconnecting...\n", __func__);
+
+       rpcrdma_ep_disconnect(ep, ia);
+
+       rc = -EHOSTUNREACH;
+       id = rpcrdma_create_id(r_xprt, ia, sap);
+       if (IS_ERR(id))
+               goto out;
+
+       /* As long as the new ID points to the same device as the
+        * old ID, we can reuse the transport's existing PD and all
+        * previously allocated MRs. Also, the same device means
+        * the transport's previous DMA mappings are still valid.
+        *
+        * This is a sanity check only. There should be no way these
+        * point to two different devices here.
+        */
+       old = id;
+       rc = -ENETUNREACH;
+       if (ia->ri_device != id->device) {
+               pr_err("rpcrdma: can't reconnect on different device!\n");
+               goto out_destroy;
+       }
+
+       err = rdma_create_qp(id, ia->ri_pd, &ep->rep_attr);
+       if (err) {
+               dprintk("RPC:       %s: rdma_create_qp returned %d\n",
+                       __func__, err);
+               goto out_destroy;
+       }
+
+       /* Atomically replace the transport's ID and QP. */
+       rc = 0;
+       old = ia->ri_id;
+       ia->ri_id = id;
+       rdma_destroy_qp(old);
+
+out_destroy:
+       rpcrdma_destroy_id(old);
+out:
+       return rc;
+}
+
 /*
  * Connect unconnected endpoint.
  */
@@ -719,61 +770,25 @@ rpcrdma_ep_connect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
 {
        struct rpcrdma_xprt *r_xprt = container_of(ia, struct rpcrdma_xprt,
                                                   rx_ia);
-       struct rdma_cm_id *id, *old;
-       struct sockaddr *sap;
        unsigned int extras;
-       int rc = 0;
+       int rc;
 
-       if (ep->rep_connected != 0) {
 retry:
-               dprintk("RPC:       %s: reconnecting...\n", __func__);
-
-               rpcrdma_ep_disconnect(ep, ia);
-
-               sap = (struct sockaddr *)&r_xprt->rx_data.addr;
-               id = rpcrdma_create_id(r_xprt, ia, sap);
-               if (IS_ERR(id)) {
-                       rc = -EHOSTUNREACH;
-                       goto out;
-               }
-               /* TEMP TEMP TEMP - fail if new device:
-                * Deregister/remarshal *all* requests!
-                * Close and recreate adapter, pd, etc!
-                * Re-determine all attributes still sane!
-                * More stuff I haven't thought of!
-                * Rrrgh!
-                */
-               if (ia->ri_device != id->device) {
-                       printk("RPC:       %s: can't reconnect on "
-                               "different device!\n", __func__);
-                       rpcrdma_destroy_id(id);
-                       rc = -ENETUNREACH;
-                       goto out;
-               }
-               /* END TEMP */
-               rc = rdma_create_qp(id, ia->ri_pd, &ep->rep_attr);
-               if (rc) {
-                       dprintk("RPC:       %s: rdma_create_qp failed %i\n",
-                               __func__, rc);
-                       rpcrdma_destroy_id(id);
-                       rc = -ENETUNREACH;
-                       goto out;
-               }
-
-               old = ia->ri_id;
-               ia->ri_id = id;
-
-               rdma_destroy_qp(old);
-               rpcrdma_destroy_id(old);
-       } else {
+       switch (ep->rep_connected) {
+       case 0:
                dprintk("RPC:       %s: connecting...\n", __func__);
                rc = rdma_create_qp(ia->ri_id, ia->ri_pd, &ep->rep_attr);
                if (rc) {
                        dprintk("RPC:       %s: rdma_create_qp failed %i\n",
                                __func__, rc);
-                       /* do not update ep->rep_connected */
-                       return -ENETUNREACH;
+                       rc = -ENETUNREACH;
+                       goto out_noupdate;
                }
+               break;
+       default:
+               rc = rpcrdma_ep_reconnect(r_xprt, ep, ia);
+               if (rc)
+                       goto out;
        }
 
        ep->rep_connected = 0;
@@ -801,6 +816,8 @@ retry:
 out:
        if (rc)
                ep->rep_connected = rc;
+
+out_noupdate:
        return rc;
 }