RPC: Ensure that we disconnect TCP socket when client requests error out
If we're part way through transmitting a TCP request, and the client
errors, then we need to disconnect and reconnect the TCP socket in order to
avoid confusing the server.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
(cherry picked from 031a50c8b9ea82616abd4a4e18021a25848941ce commit)
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 4ba271f..d6409e7 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -921,26 +921,43 @@
task->tk_status = xprt_prepare_transmit(task);
if (task->tk_status != 0)
return;
+ task->tk_action = call_transmit_status;
/* Encode here so that rpcsec_gss can use correct sequence number. */
if (rpc_task_need_encode(task)) {
- task->tk_rqstp->rq_bytes_sent = 0;
+ BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
call_encode(task);
/* Did the encode result in an error condition? */
if (task->tk_status != 0)
- goto out_nosend;
+ return;
}
- task->tk_action = call_transmit_status;
xprt_transmit(task);
if (task->tk_status < 0)
return;
- if (!task->tk_msg.rpc_proc->p_decode) {
- task->tk_action = rpc_exit_task;
- rpc_wake_up_task(task);
- }
- return;
-out_nosend:
- /* release socket write lock before attempting to handle error */
- xprt_abort_transmit(task);
+ /*
+ * On success, ensure that we call xprt_end_transmit() before sleeping
+ * in order to allow access to the socket to other RPC requests.
+ */
+ call_transmit_status(task);
+ if (task->tk_msg.rpc_proc->p_decode != NULL)
+ return;
+ task->tk_action = rpc_exit_task;
+ rpc_wake_up_task(task);
+}
+
+/*
+ * 5a. Handle cleanup after a transmission
+ */
+static void
+call_transmit_status(struct rpc_task *task)
+{
+ task->tk_action = call_status;
+ /*
+ * Special case: if we've been waiting on the socket's write_space()
+ * callback, then don't call xprt_end_transmit().
+ */
+ if (task->tk_status == -EAGAIN)
+ return;
+ xprt_end_transmit(task);
rpc_task_force_reencode(task);
}
@@ -992,18 +1009,7 @@
}
/*
- * 6a. Handle transmission errors.
- */
-static void
-call_transmit_status(struct rpc_task *task)
-{
- if (task->tk_status != -EAGAIN)
- rpc_task_force_reencode(task);
- call_status(task);
-}
-
-/*
- * 6b. Handle RPC timeout
+ * 6a. Handle RPC timeout
* We do not release the request slot, so we keep using the
* same XID for all retransmits.
*/
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index 313b68d..e8c2bc4 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -707,12 +707,9 @@
return err;
}
-void
-xprt_abort_transmit(struct rpc_task *task)
+void xprt_end_transmit(struct rpc_task *task)
{
- struct rpc_xprt *xprt = task->tk_xprt;
-
- xprt_release_write(xprt, task);
+ xprt_release_write(task->tk_xprt, task);
}
/**
@@ -761,8 +758,6 @@
task->tk_status = -ENOTCONN;
else if (!req->rq_received)
rpc_sleep_on(&xprt->pending, task, NULL, xprt_timer);
-
- xprt->ops->release_xprt(xprt, task);
spin_unlock_bh(&xprt->transport_lock);
return;
}
@@ -772,18 +767,8 @@
* schedq, and being picked up by a parallel run of rpciod().
*/
task->tk_status = status;
-
- switch (status) {
- case -ECONNREFUSED:
+ if (status == -ECONNREFUSED)
rpc_sleep_on(&xprt->sending, task, NULL, NULL);
- case -EAGAIN:
- case -ENOTCONN:
- return;
- default:
- break;
- }
- xprt_release_write(xprt, task);
- return;
}
static inline void do_xprt_reserve(struct rpc_task *task)
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index ee678ed..441bd53 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -414,6 +414,33 @@
}
/**
+ * xs_tcp_release_xprt - clean up after a tcp transmission
+ * @xprt: transport
+ * @task: rpc task
+ *
+ * This cleans up if an error causes us to abort the transmission of a request.
+ * In this case, the socket may need to be reset in order to avoid confusing
+ * the server.
+ */
+static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
+{
+ struct rpc_rqst *req;
+
+ if (task != xprt->snd_task)
+ return;
+ if (task == NULL)
+ goto out_release;
+ req = task->tk_rqstp;
+ if (req->rq_bytes_sent == 0)
+ goto out_release;
+ if (req->rq_bytes_sent == req->rq_snd_buf.len)
+ goto out_release;
+ set_bit(XPRT_CLOSE_WAIT, &task->tk_xprt->state);
+out_release:
+ xprt_release_xprt(xprt, task);
+}
+
+/**
* xs_close - close a socket
* @xprt: transport
*
@@ -1250,7 +1277,7 @@
static struct rpc_xprt_ops xs_tcp_ops = {
.reserve_xprt = xprt_reserve_xprt,
- .release_xprt = xprt_release_xprt,
+ .release_xprt = xs_tcp_release_xprt,
.set_port = xs_set_port,
.connect = xs_connect,
.buf_alloc = rpc_malloc,