xprtrdma: Simplify rpcrdma_rep_create

Clean up.

Commit 7c8d9e7c8863 ("xprtrdma: Move Receive posting to Receive
handler") reduced the number of rpcrdma_rep_create call sites to
one. After that commit, the backchannel code no longer invokes it.

Therefore the free list logic added by commit d698c4a02ee0
("xprtrdma: Fix backchannel allocation of extra rpcrdma_reps") is
no longer necessary, and in fact adds some extra overhead that we
can do without.

Simply post any newly created reps. They will get added back to
the rb_recv_bufs list when they subsequently complete.

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

1 files changed, 8 insertions, 14 deletions

diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index 4e22cc244149..de6be101abf2 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -1036,9 +1036,9 @@ out1:
         return NULL;
 }
 
-static bool rpcrdma_rep_create(struct rpcrdma_xprt *r_xprt, bool temp)
+static struct rpcrdma_rep *rpcrdma_rep_create(struct rpcrdma_xprt *r_xprt,
+                                              bool temp)
 {
-        struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
         struct rpcrdma_rep *rep;
 
         rep = kzalloc(sizeof(*rep), GFP_KERNEL);
@@ -1049,9 +1049,9 @@ static bool rpcrdma_rep_create(struct rpcrdma_xprt *r_xprt, bool temp)
                                                DMA_FROM_DEVICE, GFP_KERNEL);
         if (!rep->rr_rdmabuf)
                 goto out_free;
+
         xdr_buf_init(&rep->rr_hdrbuf, rdmab_data(rep->rr_rdmabuf),
                      rdmab_length(rep->rr_rdmabuf));
-
         rep->rr_cqe.done = rpcrdma_wc_receive;
         rep->rr_rxprt = r_xprt;
         rep->rr_recv_wr.next = NULL;
@@ -1059,16 +1059,12 @@ static bool rpcrdma_rep_create(struct rpcrdma_xprt *r_xprt, bool temp)
         rep->rr_recv_wr.sg_list = &rep->rr_rdmabuf->rg_iov;
         rep->rr_recv_wr.num_sge = 1;
         rep->rr_temp = temp;
-
-        spin_lock(&buf->rb_lock);
-        list_add(&rep->rr_list, &buf->rb_recv_bufs);
-        spin_unlock(&buf->rb_lock);
-        return true;
+        return rep;
 
 out_free:
         kfree(rep);
 out:
-        return false;
+        return NULL;
 }
 
 /**
@@ -1497,7 +1493,6 @@ rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp)
         count = 0;
         wr = NULL;
         while (needed) {
-                struct rpcrdma_regbuf *rb;
                 struct rpcrdma_rep *rep;
 
                 spin_lock(&buf->rb_lock);
@@ -1507,13 +1502,12 @@ rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp)
                         list_del(&rep->rr_list);
                 spin_unlock(&buf->rb_lock);
                 if (!rep) {
-                        if (!rpcrdma_rep_create(r_xprt, temp))
+                        rep = rpcrdma_rep_create(r_xprt, temp);
+                        if (!rep)
                                 break;
-                        continue;
                 }
 
-                rb = rep->rr_rdmabuf;
-                if (!rpcrdma_regbuf_dma_map(r_xprt, rb)) {
+                if (!rpcrdma_regbuf_dma_map(r_xprt, rep->rr_rdmabuf)) {
                         rpcrdma_recv_buffer_put(rep);
                         break;
                 }