svcrdma: Simplify RDMA_READ deferral buffer management

[firefly-linux-kernel-4.4.55.git] / net / sunrpc / xprtrdma / svc_rdma_recvfrom.c

diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
index 80c6ee82c34bad48536efda03a0269d6386b4926..21a1e625ef0305837585eaa43d4405b00bf0f66e 100644 (file)
--- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
@@ -289,7 +289,6 @@ static int rdma_read_xdr(struct svcxprt_rdma *xprt,
        u64 sgl_offset;
        struct rpcrdma_read_chunk *ch;
        struct svc_rdma_op_ctxt *ctxt = NULL;
-       struct svc_rdma_op_ctxt *head;
        struct svc_rdma_op_ctxt *tmp_sge_ctxt;
        struct svc_rdma_op_ctxt *tmp_ch_ctxt;
        struct chunk_sge *ch_sge_ary;
@@ -310,20 +309,13 @@ static int rdma_read_xdr(struct svcxprt_rdma *xprt,
        sge_count = rdma_rcl_to_sge(xprt, rqstp, hdr_ctxt, rmsgp,
                                    sge, ch_sge_ary,
                                    ch_count, byte_count);
-       head = svc_rdma_get_context(xprt);
        sgl_offset = 0;
        ch_no = 0;
 
        for (ch = (struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0];
             ch->rc_discrim != 0; ch++, ch_no++) {
 next_sge:
-               if (!ctxt)
-                       ctxt = head;
-               else {
-                       ctxt->next = svc_rdma_get_context(xprt);
-                       ctxt = ctxt->next;
-               }
-               ctxt->next = NULL;
+               ctxt = svc_rdma_get_context(xprt);
                ctxt->direction = DMA_FROM_DEVICE;
                clear_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags);
 
@@ -351,20 +343,15 @@ next_sge:
                         * the client and the RPC needs to be enqueued.
                         */
                        set_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags);
-                       ctxt->next = hdr_ctxt;
-                       hdr_ctxt->next = head;
+                       ctxt->read_hdr = hdr_ctxt;
                }
                /* Post the read */
                err = svc_rdma_send(xprt, &read_wr);
                if (err) {
-                       printk(KERN_ERR "svcrdma: Error posting send = %d\n",
+                       printk(KERN_ERR "svcrdma: Error %d posting RDMA_READ\n",
                               err);
-                       /*
-                        * Break the circular list so free knows when
-                        * to stop if the error happened to occur on
-                        * the last read
-                        */
-                       ctxt->next = NULL;
+                       set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags);
+                       svc_rdma_put_context(ctxt, 0);
                        goto out;
                }
                atomic_inc(&rdma_stat_read);
@@ -375,7 +362,7 @@ next_sge:
                        goto next_sge;
                }
                sgl_offset = 0;
-               err = 0;
+               err = 1;
        }
 
  out:
@@ -393,25 +380,12 @@ next_sge:
        while (rqstp->rq_resused)
                rqstp->rq_respages[--rqstp->rq_resused] = NULL;
 
-       if (err) {
-               printk(KERN_ERR "svcrdma : RDMA_READ error = %d\n", err);
-               set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags);
-               /* Free the linked list of read contexts */
-               while (head != NULL) {
-                       ctxt = head->next;
-                       svc_rdma_put_context(head, 1);
-                       head = ctxt;
-               }
-               return err;
-       }
-
-       return 1;
+       return err;
 }
 
 static int rdma_read_complete(struct svc_rqst *rqstp,
-                             struct svc_rdma_op_ctxt *data)
+                             struct svc_rdma_op_ctxt *head)
 {
-       struct svc_rdma_op_ctxt *head = data->next;
        int page_no;
        int ret;
 
@@ -437,22 +411,12 @@ static int rdma_read_complete(struct svc_rqst *rqstp,
        rqstp->rq_arg.len = head->arg.len;
        rqstp->rq_arg.buflen = head->arg.buflen;
 
+       /* Free the context */
+       svc_rdma_put_context(head, 0);
+
        /* XXX: What should this be? */
        rqstp->rq_prot = IPPROTO_MAX;
 
-       /*
-        * Free the contexts we used to build the RDMA_READ. We have
-        * to be careful here because the context list uses the same
-        * next pointer used to chain the contexts associated with the
-        * RDMA_READ
-        */
-       data->next = NULL;      /* terminate circular list */
-       do {
-               data = head->next;
-               svc_rdma_put_context(head, 0);
-               head = data;
-       } while (head != NULL);
-
        ret = rqstp->rq_arg.head[0].iov_len
                + rqstp->rq_arg.page_len
                + rqstp->rq_arg.tail[0].iov_len;