Commit 43ac3f29 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

SUNRPC: Fix memory barriers for req->rq_received 



We need to ensure that all writes to the XDR buffers are done before
req->rq_received is visible to other processors.

Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent c42de9dd

net/sunrpc/clnt.c

+5 −0
Original line number Diff line number Diff line
@@ -1069,6 +1069,11 @@ call_decode(struct rpc_task *task) 
		return;

	}



	/*

	 * Ensure that we see all writes made by xprt_complete_rqst()

	 * before it changed req->rq_received.

	 */

	smp_rmb();

	req->rq_rcv_buf.len = req->rq_private_buf.len;



	/* Check that the softirq receive buffer is valid */

net/sunrpc/xprt.c

+2 −1
Original line number Diff line number Diff line
@@ -651,6 +651,8 @@ void xprt_complete_rqst(struct rpc_task *task, int copied) 
	task->tk_rtt = (long)jiffies - req->rq_xtime;



	list_del_init(&req->rq_list);

	/* Ensure all writes are done before we update req->rq_received */

	smp_wmb();

	req->rq_received = req->rq_private_buf.len = copied;

	rpc_wake_up_task(task);

}
@@ -727,7 +729,6 @@ void xprt_transmit(struct rpc_task *task) 


	dprintk("RPC: %4d xprt_transmit(%u)\n", task->tk_pid, req->rq_slen);



	smp_rmb();

	if (!req->rq_received) {

		if (list_empty(&req->rq_list)) {

			spin_lock_bh(&xprt->transport_lock);