svcrdma: Simplify svc_rdma_send()

Clean up: No current caller of svc_rdma_send's passes in a chained
WR. The logic that counts the chain length can be replaced with a
constant (1).

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
index 0ebdc0c..edfeca4 100644 (file)
--- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
@@ -253,41 +253,41 @@ static void svc_rdma_wc_send(struct ib_cq *cq, struct ib_wc *wc)
        svc_xprt_put(&rdma->sc_xprt);
 }
 
+/**
+ * svc_rdma_send - Post a single Send WR
+ * @rdma: transport on which to post the WR
+ * @wr: prepared Send WR to post
+ *
+ * Returns zero the Send WR was posted successfully. Otherwise, a
+ * negative errno is returned.
+ */
 int svc_rdma_send(struct svcxprt_rdma *rdma, struct ib_send_wr *wr)
 {
-       struct ib_send_wr *bad_wr, *n_wr;
-       int wr_count;
-       int i;
+       struct ib_send_wr *bad_wr;
        int ret;
 
-       wr_count = 1;
-       for (n_wr = wr->next; n_wr; n_wr = n_wr->next)
-               wr_count++;
+       might_sleep();
 
        /* If the SQ is full, wait until an SQ entry is available */
        while (1) {
-               if ((atomic_sub_return(wr_count, &rdma->sc_sq_avail) < 0)) {
+               if ((atomic_dec_return(&rdma->sc_sq_avail) < 0)) {
                        atomic_inc(&rdma_stat_sq_starve);
                        trace_svcrdma_sq_full(rdma);
-                       atomic_add(wr_count, &rdma->sc_sq_avail);
+                       atomic_inc(&rdma->sc_sq_avail);
                        wait_event(rdma->sc_send_wait,
-                                  atomic_read(&rdma->sc_sq_avail) > wr_count);
+                                  atomic_read(&rdma->sc_sq_avail) > 1);
                        if (test_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags))
                                return -ENOTCONN;
                        trace_svcrdma_sq_retry(rdma);
                        continue;
                }
-               /* Take a transport ref for each WR posted */
-               for (i = 0; i < wr_count; i++)
-                       svc_xprt_get(&rdma->sc_xprt);
 
-               /* Bump used SQ WR count and post */
+               svc_xprt_get(&rdma->sc_xprt);
                ret = ib_post_send(rdma->sc_qp, wr, &bad_wr);
                trace_svcrdma_post_send(wr, ret);
                if (ret) {
                        set_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags);
-                       for (i = 0; i < wr_count; i++)
-                               svc_xprt_put(&rdma->sc_xprt);
+                       svc_xprt_put(&rdma->sc_xprt);
                        wake_up(&rdma->sc_send_wait);
                }
                break;