xprtrdma: Pre-allocate backward rpc_rqst and send/receive buffers
xprtrdma's backward direction send and receive buffers are the same
size as the forechannel's inline threshold, and must be pre-
registered.
The consumer has no control over which receive buffer the adapter
chooses to catch an incoming backwards-direction call. Any receive
buffer can be used for either a forward reply or a backward call.
Thus both types of RPC message must all be the same size.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Tested-By: Devesh Sharma <devesh.sharma@avagotech.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 baa0523..7f0ed30 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -831,7 +831,21 @@
}
rc = ep->rep_connected;
} else {
+ struct rpcrdma_xprt *r_xprt;
+ unsigned int extras;
+
dprintk("RPC: %s: connected\n", __func__);
+
+ r_xprt = container_of(ia, struct rpcrdma_xprt, rx_ia);
+ extras = r_xprt->rx_buf.rb_bc_srv_max_requests;
+
+ if (extras) {
+ rc = rpcrdma_ep_post_extra_recv(r_xprt, extras);
+ if (rc)
+ pr_warn("%s: rpcrdma_ep_post_extra_recv: %i\n",
+ __func__, rc);
+ rc = 0;
+ }
}
out:
@@ -868,20 +882,25 @@
}
}
-static struct rpcrdma_req *
+struct rpcrdma_req *
rpcrdma_create_req(struct rpcrdma_xprt *r_xprt)
{
+ struct rpcrdma_buffer *buffer = &r_xprt->rx_buf;
struct rpcrdma_req *req;
req = kzalloc(sizeof(*req), GFP_KERNEL);
if (req == NULL)
return ERR_PTR(-ENOMEM);
+ INIT_LIST_HEAD(&req->rl_free);
+ spin_lock(&buffer->rb_reqslock);
+ list_add(&req->rl_all, &buffer->rb_allreqs);
+ spin_unlock(&buffer->rb_reqslock);
req->rl_buffer = &r_xprt->rx_buf;
return req;
}
-static struct rpcrdma_rep *
+struct rpcrdma_rep *
rpcrdma_create_rep(struct rpcrdma_xprt *r_xprt)
{
struct rpcrdma_create_data_internal *cdata = &r_xprt->rx_data;
@@ -920,6 +939,7 @@
int i, rc;
buf->rb_max_requests = r_xprt->rx_data.max_requests;
+ buf->rb_bc_srv_max_requests = 0;
spin_lock_init(&buf->rb_lock);
rc = ia->ri_ops->ro_init(r_xprt);
@@ -927,6 +947,8 @@
goto out;
INIT_LIST_HEAD(&buf->rb_send_bufs);
+ INIT_LIST_HEAD(&buf->rb_allreqs);
+ spin_lock_init(&buf->rb_reqslock);
for (i = 0; i < buf->rb_max_requests; i++) {
struct rpcrdma_req *req;
@@ -937,6 +959,7 @@
rc = PTR_ERR(req);
goto out;
}
+ req->rl_backchannel = false;
list_add(&req->rl_free, &buf->rb_send_bufs);
}
@@ -985,19 +1008,13 @@
static void
rpcrdma_destroy_rep(struct rpcrdma_ia *ia, struct rpcrdma_rep *rep)
{
- if (!rep)
- return;
-
rpcrdma_free_regbuf(ia, rep->rr_rdmabuf);
kfree(rep);
}
-static void
+void
rpcrdma_destroy_req(struct rpcrdma_ia *ia, struct rpcrdma_req *req)
{
- if (!req)
- return;
-
rpcrdma_free_regbuf(ia, req->rl_sendbuf);
rpcrdma_free_regbuf(ia, req->rl_rdmabuf);
kfree(req);
@@ -1015,12 +1032,19 @@
rpcrdma_destroy_rep(ia, rep);
}
- while (!list_empty(&buf->rb_send_bufs)) {
+ spin_lock(&buf->rb_reqslock);
+ while (!list_empty(&buf->rb_allreqs)) {
struct rpcrdma_req *req;
- req = rpcrdma_buffer_get_req_locked(buf);
+ req = list_first_entry(&buf->rb_allreqs,
+ struct rpcrdma_req, rl_all);
+ list_del(&req->rl_all);
+
+ spin_unlock(&buf->rb_reqslock);
rpcrdma_destroy_req(ia, req);
+ spin_lock(&buf->rb_reqslock);
}
+ spin_unlock(&buf->rb_reqslock);
ia->ri_ops->ro_destroy(buf);
}
@@ -1288,6 +1312,47 @@
return rc;
}
+/**
+ * rpcrdma_ep_post_extra_recv - Post buffers for incoming backchannel requests
+ * @r_xprt: transport associated with these backchannel resources
+ * @min_reqs: minimum number of incoming requests expected
+ *
+ * Returns zero if all requested buffers were posted, or a negative errno.
+ */
+int
+rpcrdma_ep_post_extra_recv(struct rpcrdma_xprt *r_xprt, unsigned int count)
+{
+ struct rpcrdma_buffer *buffers = &r_xprt->rx_buf;
+ struct rpcrdma_ia *ia = &r_xprt->rx_ia;
+ struct rpcrdma_ep *ep = &r_xprt->rx_ep;
+ struct rpcrdma_rep *rep;
+ unsigned long flags;
+ int rc;
+
+ while (count--) {
+ spin_lock_irqsave(&buffers->rb_lock, flags);
+ if (list_empty(&buffers->rb_recv_bufs))
+ goto out_reqbuf;
+ rep = rpcrdma_buffer_get_rep_locked(buffers);
+ spin_unlock_irqrestore(&buffers->rb_lock, flags);
+
+ rc = rpcrdma_ep_post_recv(ia, ep, rep);
+ if (rc)
+ goto out_rc;
+ }
+
+ return 0;
+
+out_reqbuf:
+ spin_unlock_irqrestore(&buffers->rb_lock, flags);
+ pr_warn("%s: no extra receive buffers\n", __func__);
+ return -ENOMEM;
+
+out_rc:
+ rpcrdma_recv_buffer_put(rep);
+ return rc;
+}
+
/* How many chunk list items fit within our inline buffers?
*/
unsigned int