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>

diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index 4e22cc244149a2ed58171b1e3603c680ddb4d56b..de6be101abf231e67ec61090071d624358265db4 100644 (file)
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -1036,9 +1036,9 @@ struct rpcrdma_req *rpcrdma_req_create(struct rpcrdma_xprt *r_xprt, size_t size,
        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;
                }