SUNRPC: Add a separate spinlock to protect the RPC request receive list
This further reduces contention with the transport_lock, and allows us
to convert to using a non-bh-safe spinlock, since the list is now never
accessed from a bh context.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 2b720fa..272063c 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -1001,7 +1001,7 @@
if (!bc_xprt)
return -EAGAIN;
- spin_lock_bh(&bc_xprt->transport_lock);
+ spin_lock(&bc_xprt->recv_lock);
req = xprt_lookup_rqst(bc_xprt, xid);
if (!req)
goto unlock_notfound;
@@ -1019,7 +1019,7 @@
memcpy(dst->iov_base, src->iov_base, src->iov_len);
xprt_complete_rqst(req->rq_task, rqstp->rq_arg.len);
rqstp->rq_arg.len = 0;
- spin_unlock_bh(&bc_xprt->transport_lock);
+ spin_unlock(&bc_xprt->recv_lock);
return 0;
unlock_notfound:
printk(KERN_NOTICE
@@ -1028,7 +1028,7 @@
__func__, ntohl(calldir),
bc_xprt, ntohl(xid));
unlock_eagain:
- spin_unlock_bh(&bc_xprt->transport_lock);
+ spin_unlock(&bc_xprt->recv_lock);
return -EAGAIN;
}
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index 3eb9ec1..2af189c 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -872,17 +872,17 @@
}
static void xprt_wait_on_pinned_rqst(struct rpc_rqst *req)
-__must_hold(&req->rq_xprt->transport_lock)
+__must_hold(&req->rq_xprt->recv_lock)
{
struct rpc_task *task = req->rq_task;
if (task && test_bit(RPC_TASK_MSG_RECV, &task->tk_runstate)) {
- spin_unlock_bh(&req->rq_xprt->transport_lock);
+ spin_unlock(&req->rq_xprt->recv_lock);
set_bit(RPC_TASK_MSG_RECV_WAIT, &task->tk_runstate);
wait_on_bit(&task->tk_runstate, RPC_TASK_MSG_RECV,
TASK_UNINTERRUPTIBLE);
clear_bit(RPC_TASK_MSG_RECV_WAIT, &task->tk_runstate);
- spin_lock_bh(&req->rq_xprt->transport_lock);
+ spin_lock(&req->rq_xprt->recv_lock);
}
}
@@ -1008,13 +1008,13 @@
/*
* Add to the list only if we're expecting a reply
*/
- spin_lock_bh(&xprt->transport_lock);
/* Update the softirq receive buffer */
memcpy(&req->rq_private_buf, &req->rq_rcv_buf,
sizeof(req->rq_private_buf));
/* Add request to the receive list */
+ spin_lock(&xprt->recv_lock);
list_add_tail(&req->rq_list, &xprt->recv);
- spin_unlock_bh(&xprt->transport_lock);
+ spin_unlock(&xprt->recv_lock);
xprt_reset_majortimeo(req);
/* Turn off autodisconnect */
del_singleshot_timer_sync(&xprt->timer);
@@ -1329,15 +1329,18 @@
task->tk_ops->rpc_count_stats(task, task->tk_calldata);
else if (task->tk_client)
rpc_count_iostats(task, task->tk_client->cl_metrics);
+ spin_lock(&xprt->recv_lock);
+ if (!list_empty(&req->rq_list)) {
+ list_del(&req->rq_list);
+ xprt_wait_on_pinned_rqst(req);
+ }
+ spin_unlock(&xprt->recv_lock);
spin_lock_bh(&xprt->transport_lock);
xprt->ops->release_xprt(xprt, task);
if (xprt->ops->release_request)
xprt->ops->release_request(task);
- if (!list_empty(&req->rq_list))
- list_del(&req->rq_list);
xprt->last_used = jiffies;
xprt_schedule_autodisconnect(xprt);
- xprt_wait_on_pinned_rqst(req);
spin_unlock_bh(&xprt->transport_lock);
if (req->rq_buffer)
xprt->ops->buf_free(task);
@@ -1361,6 +1364,7 @@
spin_lock_init(&xprt->transport_lock);
spin_lock_init(&xprt->reserve_lock);
+ spin_lock_init(&xprt->recv_lock);
INIT_LIST_HEAD(&xprt->free);
INIT_LIST_HEAD(&xprt->recv);
diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c
index ca4d6e4..dfa748a 100644
--- a/net/sunrpc/xprtrdma/rpc_rdma.c
+++ b/net/sunrpc/xprtrdma/rpc_rdma.c
@@ -1051,7 +1051,7 @@
* RPC completion while holding the transport lock to ensure
* the rep, rqst, and rq_task pointers remain stable.
*/
- spin_lock_bh(&xprt->transport_lock);
+ spin_lock(&xprt->recv_lock);
rqst = xprt_lookup_rqst(xprt, headerp->rm_xid);
if (!rqst)
goto out_norqst;
@@ -1136,7 +1136,7 @@
xprt_release_rqst_cong(rqst->rq_task);
xprt_complete_rqst(rqst->rq_task, status);
- spin_unlock_bh(&xprt->transport_lock);
+ spin_unlock(&xprt->recv_lock);
dprintk("RPC: %s: xprt_complete_rqst(0x%p, 0x%p, %d)\n",
__func__, xprt, rqst, status);
return;
@@ -1187,12 +1187,12 @@
r_xprt->rx_stats.bad_reply_count++;
goto out;
-/* The req was still available, but by the time the transport_lock
+/* The req was still available, but by the time the recv_lock
* was acquired, the rqst and task had been released. Thus the RPC
* has already been terminated.
*/
out_norqst:
- spin_unlock_bh(&xprt->transport_lock);
+ spin_unlock(&xprt->recv_lock);
rpcrdma_buffer_put(req);
dprintk("RPC: %s: race, no rqst left for req %p\n",
__func__, req);
diff --git a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c
index c676ed0..0d574cd 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c
@@ -52,7 +52,7 @@
if (src->iov_len < 24)
goto out_shortreply;
- spin_lock_bh(&xprt->transport_lock);
+ spin_lock(&xprt->recv_lock);
req = xprt_lookup_rqst(xprt, xid);
if (!req)
goto out_notfound;
@@ -69,17 +69,20 @@
else if (credits > r_xprt->rx_buf.rb_bc_max_requests)
credits = r_xprt->rx_buf.rb_bc_max_requests;
+ spin_lock_bh(&xprt->transport_lock);
cwnd = xprt->cwnd;
xprt->cwnd = credits << RPC_CWNDSHIFT;
if (xprt->cwnd > cwnd)
xprt_release_rqst_cong(req->rq_task);
+ spin_unlock_bh(&xprt->transport_lock);
+
ret = 0;
xprt_complete_rqst(req->rq_task, rcvbuf->len);
rcvbuf->len = 0;
out_unlock:
- spin_unlock_bh(&xprt->transport_lock);
+ spin_unlock(&xprt->recv_lock);
out:
return ret;
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index a344bea..2b91813 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -969,12 +969,12 @@
return;
/* Look up and lock the request corresponding to the given XID */
- spin_lock_bh(&xprt->transport_lock);
+ spin_lock(&xprt->recv_lock);
rovr = xprt_lookup_rqst(xprt, *xp);
if (!rovr)
goto out_unlock;
xprt_pin_rqst(rovr);
- spin_unlock_bh(&xprt->transport_lock);
+ spin_unlock(&xprt->recv_lock);
task = rovr->rq_task;
copied = rovr->rq_private_buf.buflen;
@@ -983,16 +983,16 @@
if (xs_local_copy_to_xdr(&rovr->rq_private_buf, skb)) {
dprintk("RPC: sk_buff copy failed\n");
- spin_lock_bh(&xprt->transport_lock);
+ spin_lock(&xprt->recv_lock);
goto out_unpin;
}
- spin_lock_bh(&xprt->transport_lock);
+ spin_lock(&xprt->recv_lock);
xprt_complete_rqst(task, copied);
out_unpin:
xprt_unpin_rqst(rovr);
out_unlock:
- spin_unlock_bh(&xprt->transport_lock);
+ spin_unlock(&xprt->recv_lock);
}
static void xs_local_data_receive(struct sock_xprt *transport)
@@ -1055,12 +1055,12 @@
return;
/* Look up and lock the request corresponding to the given XID */
- spin_lock_bh(&xprt->transport_lock);
+ spin_lock(&xprt->recv_lock);
rovr = xprt_lookup_rqst(xprt, *xp);
if (!rovr)
goto out_unlock;
xprt_pin_rqst(rovr);
- spin_unlock_bh(&xprt->transport_lock);
+ spin_unlock(&xprt->recv_lock);
task = rovr->rq_task;
if ((copied = rovr->rq_private_buf.buflen) > repsize)
@@ -1069,7 +1069,7 @@
/* Suck it into the iovec, verify checksum if not done by hw. */
if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
__UDPX_INC_STATS(sk, UDP_MIB_INERRORS);
- spin_lock_bh(&xprt->transport_lock);
+ spin_lock(&xprt->recv_lock);
goto out_unpin;
}
@@ -1077,11 +1077,13 @@
spin_lock_bh(&xprt->transport_lock);
xprt_adjust_cwnd(xprt, task, copied);
+ spin_unlock_bh(&xprt->transport_lock);
+ spin_lock(&xprt->recv_lock);
xprt_complete_rqst(task, copied);
out_unpin:
xprt_unpin_rqst(rovr);
out_unlock:
- spin_unlock_bh(&xprt->transport_lock);
+ spin_unlock(&xprt->recv_lock);
}
static void xs_udp_data_receive(struct sock_xprt *transport)
@@ -1344,24 +1346,24 @@
dprintk("RPC: read reply XID %08x\n", ntohl(transport->tcp_xid));
/* Find and lock the request corresponding to this xid */
- spin_lock_bh(&xprt->transport_lock);
+ spin_lock(&xprt->recv_lock);
req = xprt_lookup_rqst(xprt, transport->tcp_xid);
if (!req) {
dprintk("RPC: XID %08x request not found!\n",
ntohl(transport->tcp_xid));
- spin_unlock_bh(&xprt->transport_lock);
+ spin_unlock(&xprt->recv_lock);
return -1;
}
xprt_pin_rqst(req);
- spin_unlock_bh(&xprt->transport_lock);
+ spin_unlock(&xprt->recv_lock);
xs_tcp_read_common(xprt, desc, req);
- spin_lock_bh(&xprt->transport_lock);
+ spin_lock(&xprt->recv_lock);
if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
xprt_complete_rqst(req->rq_task, transport->tcp_copied);
xprt_unpin_rqst(req);
- spin_unlock_bh(&xprt->transport_lock);
+ spin_unlock(&xprt->recv_lock);
return 0;
}