1 files changed, 64 insertions, 29 deletions

diff --git a/net/sunrpc/backchannel_rqst.c b/net/sunrpc/backchannel_rqst.c
index e860d4f7ed2a..3513d559bc45 100644
--- a/net/sunrpc/backchannel_rqst.c
+++ b/net/sunrpc/backchannel_rqst.c
@@ -212,39 +212,23 @@ out:
 }
 EXPORT_SYMBOL_GPL(xprt_destroy_backchannel);
 
-/*
- * One or more rpc_rqst structure have been preallocated during the
- * backchannel setup.  Buffer space for the send and private XDR buffers
- * has been preallocated as well.  Use xprt_alloc_bc_request to allocate
- * to this request.  Use xprt_free_bc_request to return it.
- *
- * We know that we're called in soft interrupt context, grab the spin_lock
- * since there is no need to grab the bottom half spin_lock.
- *
- * Return an available rpc_rqst, otherwise NULL if non are available.
- */
-struct rpc_rqst *xprt_alloc_bc_request(struct rpc_xprt *xprt)
+static struct rpc_rqst *xprt_alloc_bc_request(struct rpc_xprt *xprt, __be32 xid)
 {
-        struct rpc_rqst *req;
+        struct rpc_rqst *req = NULL;
 
         dprintk("RPC:       allocate a backchannel request\n");
-        spin_lock(&xprt->bc_pa_lock);
-        if (!list_empty(&xprt->bc_pa_list)) {
-                req = list_first_entry(&xprt->bc_pa_list, struct rpc_rqst,
-                                rq_bc_pa_list);
-                list_del(&req->rq_bc_pa_list);
-        } else {
-                req = NULL;
-        }
-        spin_unlock(&xprt->bc_pa_lock);
+        if (list_empty(&xprt->bc_pa_list))
+                goto not_found;
 
-        if (req != NULL) {
-                set_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
-                req->rq_reply_bytes_recvd = 0;
-                req->rq_bytes_sent = 0;
-                memcpy(&req->rq_private_buf, &req->rq_rcv_buf,
+        req = list_first_entry(&xprt->bc_pa_list, struct rpc_rqst,
+                                rq_bc_pa_list);
+        req->rq_reply_bytes_recvd = 0;
+        req->rq_bytes_sent = 0;
+        memcpy(&req->rq_private_buf, &req->rq_rcv_buf,
                         sizeof(req->rq_private_buf));
-        }
+        req->rq_xid = xid;
+        req->rq_connect_cookie = xprt->connect_cookie;
+not_found:
         dprintk("RPC:       backchannel req=%p\n", req);
         return req;
 }
@@ -259,6 +243,7 @@ void xprt_free_bc_request(struct rpc_rqst *req)
 
         dprintk("RPC:       free backchannel req=%p\n", req);
 
+        req->rq_connect_cookie = xprt->connect_cookie - 1;
         smp_mb__before_clear_bit();
         WARN_ON_ONCE(!test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state));
         clear_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
@@ -281,7 +266,57 @@ void xprt_free_bc_request(struct rpc_rqst *req)
          * may be reused by a new callback request.
          */
         spin_lock_bh(&xprt->bc_pa_lock);
-        list_add(&req->rq_bc_pa_list, &xprt->bc_pa_list);
+        list_add_tail(&req->rq_bc_pa_list, &xprt->bc_pa_list);
         spin_unlock_bh(&xprt->bc_pa_lock);
 }
 
+/*
+ * One or more rpc_rqst structure have been preallocated during the
+ * backchannel setup.  Buffer space for the send and private XDR buffers
+ * has been preallocated as well.  Use xprt_alloc_bc_request to allocate
+ * to this request.  Use xprt_free_bc_request to return it.
+ *
+ * We know that we're called in soft interrupt context, grab the spin_lock
+ * since there is no need to grab the bottom half spin_lock.
+ *
+ * Return an available rpc_rqst, otherwise NULL if non are available.
+ */
+struct rpc_rqst *xprt_lookup_bc_request(struct rpc_xprt *xprt, __be32 xid)
+{
+        struct rpc_rqst *req;
+
+        spin_lock(&xprt->bc_pa_lock);
+        list_for_each_entry(req, &xprt->bc_pa_list, rq_bc_pa_list) {
+                if (req->rq_connect_cookie != xprt->connect_cookie)
+                        continue;
+                if (req->rq_xid == xid)
+                        goto found;
+        }
+        req = xprt_alloc_bc_request(xprt, xid);
+found:
+        spin_unlock(&xprt->bc_pa_lock);
+        return req;
+}
+
+/*
+ * Add callback request to callback list.  The callback
+ * service sleeps on the sv_cb_waitq waiting for new
+ * requests.  Wake it up after adding enqueing the
+ * request.
+ */
+void xprt_complete_bc_request(struct rpc_rqst *req, uint32_t copied)
+{
+        struct rpc_xprt *xprt = req->rq_xprt;
+        struct svc_serv *bc_serv = xprt->bc_serv;
+
+        req->rq_private_buf.len = copied;
+        set_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
+
+        dprintk("RPC:       add callback request to list\n");
+        spin_lock(&bc_serv->sv_cb_lock);
+        list_del(&req->rq_bc_pa_list);
+        list_add(&req->rq_bc_list, &bc_serv->sv_cb_list);
+        wake_up(&bc_serv->sv_cb_waitq);
+        spin_unlock(&bc_serv->sv_cb_lock);
+}
+