Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux
[firefly-linux-kernel-4.4.55.git] / net / sunrpc / xprtrdma / rpc_rdma.c
index bc8bd6577467d5d2346b452a3c0d3c65411b3639..c10d9699441c3390d384e90f7dfc15ef9cd0ee27 100644 (file)
@@ -441,6 +441,11 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst)
        enum rpcrdma_chunktype rtype, wtype;
        struct rpcrdma_msg *headerp;
 
+#if defined(CONFIG_SUNRPC_BACKCHANNEL)
+       if (test_bit(RPC_BC_PA_IN_USE, &rqst->rq_bc_pa_state))
+               return rpcrdma_bc_marshal_reply(rqst);
+#endif
+
        /*
         * rpclen gets amount of data in first buffer, which is the
         * pre-registered buffer.
@@ -711,6 +716,37 @@ rpcrdma_connect_worker(struct work_struct *work)
        spin_unlock_bh(&xprt->transport_lock);
 }
 
+#if defined(CONFIG_SUNRPC_BACKCHANNEL)
+/* By convention, backchannel calls arrive via rdma_msg type
+ * messages, and never populate the chunk lists. This makes
+ * the RPC/RDMA header small and fixed in size, so it is
+ * straightforward to check the RPC header's direction field.
+ */
+static bool
+rpcrdma_is_bcall(struct rpcrdma_msg *headerp)
+{
+       __be32 *p = (__be32 *)headerp;
+
+       if (headerp->rm_type != rdma_msg)
+               return false;
+       if (headerp->rm_body.rm_chunks[0] != xdr_zero)
+               return false;
+       if (headerp->rm_body.rm_chunks[1] != xdr_zero)
+               return false;
+       if (headerp->rm_body.rm_chunks[2] != xdr_zero)
+               return false;
+
+       /* sanity */
+       if (p[7] != headerp->rm_xid)
+               return false;
+       /* call direction */
+       if (p[8] != cpu_to_be32(RPC_CALL))
+               return false;
+
+       return true;
+}
+#endif /* CONFIG_SUNRPC_BACKCHANNEL */
+
 /*
  * This function is called when an async event is posted to
  * the connection which changes the connection state. All it
@@ -723,8 +759,8 @@ rpcrdma_conn_func(struct rpcrdma_ep *ep)
        schedule_delayed_work(&ep->rep_connect_worker, 0);
 }
 
-/*
- * Called as a tasklet to do req/reply match and complete a request
+/* Process received RPC/RDMA messages.
+ *
  * Errors must result in the RPC task either being awakened, or
  * allowed to timeout, to discover the errors at that time.
  */
@@ -741,52 +777,32 @@ rpcrdma_reply_handler(struct rpcrdma_rep *rep)
        unsigned long cwnd;
        u32 credits;
 
-       /* Check status. If bad, signal disconnect and return rep to pool */
-       if (rep->rr_len == ~0U) {
-               rpcrdma_recv_buffer_put(rep);
-               if (r_xprt->rx_ep.rep_connected == 1) {
-                       r_xprt->rx_ep.rep_connected = -EIO;
-                       rpcrdma_conn_func(&r_xprt->rx_ep);
-               }
-               return;
-       }
-       if (rep->rr_len < RPCRDMA_HDRLEN_MIN) {
-               dprintk("RPC:       %s: short/invalid reply\n", __func__);
-               goto repost;
-       }
+       dprintk("RPC:       %s: incoming rep %p\n", __func__, rep);
+
+       if (rep->rr_len == RPCRDMA_BAD_LEN)
+               goto out_badstatus;
+       if (rep->rr_len < RPCRDMA_HDRLEN_MIN)
+               goto out_shortreply;
+
        headerp = rdmab_to_msg(rep->rr_rdmabuf);
-       if (headerp->rm_vers != rpcrdma_version) {
-               dprintk("RPC:       %s: invalid version %d\n",
-                       __func__, be32_to_cpu(headerp->rm_vers));
-               goto repost;
-       }
+       if (headerp->rm_vers != rpcrdma_version)
+               goto out_badversion;
+#if defined(CONFIG_SUNRPC_BACKCHANNEL)
+       if (rpcrdma_is_bcall(headerp))
+               goto out_bcall;
+#endif
 
-       /* Get XID and try for a match. */
-       spin_lock(&xprt->transport_lock);
+       /* Match incoming rpcrdma_rep to an rpcrdma_req to
+        * get context for handling any incoming chunks.
+        */
+       spin_lock_bh(&xprt->transport_lock);
        rqst = xprt_lookup_rqst(xprt, headerp->rm_xid);
-       if (rqst == NULL) {
-               spin_unlock(&xprt->transport_lock);
-               dprintk("RPC:       %s: reply 0x%p failed "
-                       "to match any request xid 0x%08x len %d\n",
-                       __func__, rep, be32_to_cpu(headerp->rm_xid),
-                       rep->rr_len);
-repost:
-               r_xprt->rx_stats.bad_reply_count++;
-               if (rpcrdma_ep_post_recv(&r_xprt->rx_ia, &r_xprt->rx_ep, rep))
-                       rpcrdma_recv_buffer_put(rep);
+       if (!rqst)
+               goto out_nomatch;
 
-               return;
-       }
-
-       /* get request object */
        req = rpcr_to_rdmar(rqst);
-       if (req->rl_reply) {
-               spin_unlock(&xprt->transport_lock);
-               dprintk("RPC:       %s: duplicate reply 0x%p to RPC "
-                       "request 0x%p: xid 0x%08x\n", __func__, rep, req,
-                       be32_to_cpu(headerp->rm_xid));
-               goto repost;
-       }
+       if (req->rl_reply)
+               goto out_duplicate;
 
        dprintk("RPC:       %s: reply 0x%p completes request 0x%p\n"
                "                   RPC request 0x%p xid 0x%08x\n",
@@ -883,8 +899,50 @@ badheader:
        if (xprt->cwnd > cwnd)
                xprt_release_rqst_cong(rqst->rq_task);
 
+       xprt_complete_rqst(rqst->rq_task, status);
+       spin_unlock_bh(&xprt->transport_lock);
        dprintk("RPC:       %s: xprt_complete_rqst(0x%p, 0x%p, %d)\n",
                        __func__, xprt, rqst, status);
-       xprt_complete_rqst(rqst->rq_task, status);
-       spin_unlock(&xprt->transport_lock);
+       return;
+
+out_badstatus:
+       rpcrdma_recv_buffer_put(rep);
+       if (r_xprt->rx_ep.rep_connected == 1) {
+               r_xprt->rx_ep.rep_connected = -EIO;
+               rpcrdma_conn_func(&r_xprt->rx_ep);
+       }
+       return;
+
+#if defined(CONFIG_SUNRPC_BACKCHANNEL)
+out_bcall:
+       rpcrdma_bc_receive_call(r_xprt, rep);
+       return;
+#endif
+
+out_shortreply:
+       dprintk("RPC:       %s: short/invalid reply\n", __func__);
+       goto repost;
+
+out_badversion:
+       dprintk("RPC:       %s: invalid version %d\n",
+               __func__, be32_to_cpu(headerp->rm_vers));
+       goto repost;
+
+out_nomatch:
+       spin_unlock_bh(&xprt->transport_lock);
+       dprintk("RPC:       %s: no match for incoming xid 0x%08x len %d\n",
+               __func__, be32_to_cpu(headerp->rm_xid),
+               rep->rr_len);
+       goto repost;
+
+out_duplicate:
+       spin_unlock_bh(&xprt->transport_lock);
+       dprintk("RPC:       %s: "
+               "duplicate reply %p to RPC request %p: xid 0x%08x\n",
+               __func__, rep, req, be32_to_cpu(headerp->rm_xid));
+
+repost:
+       r_xprt->rx_stats.bad_reply_count++;
+       if (rpcrdma_ep_post_recv(&r_xprt->rx_ia, &r_xprt->rx_ep, rep))
+               rpcrdma_recv_buffer_put(rep);
 }