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: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
This commit is contained in:
Trond Myklebust 2022-03-14 21:02:10 -04:00
parent 3b21f757c3
commit 7496b59f58

View File

@ -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;
@ -780,16 +780,6 @@ static int xs_nospace(struct rpc_rqst *req)
/* Don't race with disconnect */
if (xprt_connected(xprt)) {
/* wait for more buffer space */
sk->sk_write_pending++;
xprt_wait_for_buffer_space(xprt);
} else
ret = -ENOTCONN;
spin_unlock(&xprt->transport_lock);
/* Race breaker in case memory is freed before above code is called */
if (ret == -EAGAIN) {
struct socket_wq *wq;
rcu_read_lock();
@ -797,8 +787,42 @@ static int xs_nospace(struct rpc_rqst *req)
set_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags);
rcu_read_unlock();
sk->sk_write_space(sk);
}
/* 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;
}
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;
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 @@ process_status:
/* 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: