From: Trond Myklebust trond.myklebust@hammerspace.com
[ Upstream commit 7496b59f588dd52886fdbac7633608097543a0a5 ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- net/sunrpc/xprtsock.c | 54 +++++++++++++++++++++++++++++++------------ 1 file changed, 39 insertions(+), 15 deletions(-)
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index 11eab0f0333b..5eb05c2dd6d6 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -763,12 +763,12 @@ 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;
@@ -779,25 +779,49 @@ 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; +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;
- rcu_read_lock(); - wq = rcu_dereference(sk->sk_wq); - set_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags); - rcu_read_unlock(); + lock_sock(sk); + if (!sock_writeable(sk)) + ret = xs_nospace(req, transport); + release_sock(sk); + return ret; +}
- sk->sk_write_space(sk); - } +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; }
@@ -887,7 +911,7 @@ 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", @@ -963,7 +987,7 @@ 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: @@ -1083,7 +1107,7 @@ 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: