Commit 7496b59f authored by Trond Myklebust's avatar Trond Myklebust
Browse files

SUNRPC: Fix socket waits for write buffer space 



The socket layer requires that we use the socket lock to protect changes
to the sock->sk_write_pending field and others.

Reported-by: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
parent 3b21f757

net/sunrpc/xprtsock.c

+39 −15
Original line number Diff line number Diff line
@@ -764,12 +764,12 @@ xs_stream_start_connect(struct sock_xprt *transport) 
/**

 * xs_nospace - handle transmit was incomplete

 * @req: pointer to RPC request

 * @transport: pointer to struct sock_xprt

 *

 */

static int xs_nospace(struct rpc_rqst *req)

static int xs_nospace(struct rpc_rqst *req, struct sock_xprt *transport)

{

	struct rpc_xprt *xprt = req->rq_xprt;

	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);

	struct rpc_xprt *xprt = &transport->xprt;

	struct sock *sk = transport->inet;

	int ret = -EAGAIN;
@@ -780,25 +780,49 @@ static int xs_nospace(struct rpc_rqst *req) 


	/* Don't race with disconnect */

	if (xprt_connected(xprt)) {

		struct socket_wq *wq;



		rcu_read_lock();

		wq = rcu_dereference(sk->sk_wq);

		set_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags);

		rcu_read_unlock();



		/* wait for more buffer space */

		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);

		sk->sk_write_pending++;

		xprt_wait_for_buffer_space(xprt);

	} else

		ret = -ENOTCONN;



	spin_unlock(&xprt->transport_lock);

	return ret;

}



	/* Race breaker in case memory is freed before above code is called */

	if (ret == -EAGAIN) {

		struct socket_wq *wq;



		rcu_read_lock();

		wq = rcu_dereference(sk->sk_wq);

		set_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags);

		rcu_read_unlock();

static int xs_sock_nospace(struct rpc_rqst *req)

{

	struct sock_xprt *transport =

		container_of(req->rq_xprt, struct sock_xprt, xprt);

	struct sock *sk = transport->inet;

	int ret = -EAGAIN;



		sk->sk_write_space(sk);

	lock_sock(sk);

	if (!sock_writeable(sk))

		ret = xs_nospace(req, transport);

	release_sock(sk);

	return ret;

}



static int xs_stream_nospace(struct rpc_rqst *req)

{

	struct sock_xprt *transport =

		container_of(req->rq_xprt, struct sock_xprt, xprt);

	struct sock *sk = transport->inet;

	int ret = -EAGAIN;



	lock_sock(sk);

	if (!sk_stream_memory_free(sk))

		ret = xs_nospace(req, transport);

	release_sock(sk);

	return ret;

}
@@ -888,7 +912,7 @@ static int xs_local_send_request(struct rpc_rqst *req) 
	case -ENOBUFS:

		break;

	case -EAGAIN:

		status = xs_nospace(req);

		status = xs_stream_nospace(req);

		break;

	default:

		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
@@ -964,7 +988,7 @@ static int xs_udp_send_request(struct rpc_rqst *req) 
		/* Should we call xs_close() here? */

		break;

	case -EAGAIN:

		status = xs_nospace(req);

		status = xs_sock_nospace(req);

		break;

	case -ENETUNREACH:

	case -ENOBUFS:
@@ -1086,7 +1110,7 @@ static int xs_tcp_send_request(struct rpc_rqst *req) 
		/* Should we call xs_close() here? */

		break;

	case -EAGAIN:

		status = xs_nospace(req);

		status = xs_stream_nospace(req);

		break;

	case -ECONNRESET:

	case -ECONNREFUSED: