[PATCH] SUNRPC: don't reencode when looping in call transmit.
If the call to xprt_transmit() fails due to socket buffer space
exhaustion, we do not need to re-encode the RPC message when we
loop back through call_transmit.
Re-encoding can actually end up triggering the WARN_ON() in
call_decode() if we re-encode something like a read() request and
auth->au_rslack has changed.
It can also cause us to increment the RPCSEC_GSS sequence number
beyond the limits of the allowed window.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 702ede3..61c3abe 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -55,6 +55,7 @@
static void call_bind_status(struct rpc_task *task);
static void call_transmit(struct rpc_task *task);
static void call_status(struct rpc_task *task);
+static void call_transmit_status(struct rpc_task *task);
static void call_refresh(struct rpc_task *task);
static void call_refreshresult(struct rpc_task *task);
static void call_timeout(struct rpc_task *task);
@@ -672,6 +673,18 @@
rpc_exit(task, -ERESTARTSYS);
}
+static inline int
+rpc_task_need_encode(struct rpc_task *task)
+{
+ return task->tk_rqstp->rq_snd_buf.len == 0;
+}
+
+static inline void
+rpc_task_force_reencode(struct rpc_task *task)
+{
+ task->tk_rqstp->rq_snd_buf.len = 0;
+}
+
/*
* 3. Encode arguments of an RPC call
*/
@@ -867,12 +880,14 @@
if (task->tk_status != 0)
return;
/* Encode here so that rpcsec_gss can use correct sequence number. */
- if (task->tk_rqstp->rq_bytes_sent == 0) {
+ if (rpc_task_need_encode(task)) {
+ 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;
}
+ task->tk_action = call_transmit_status;
xprt_transmit(task);
if (task->tk_status < 0)
return;
@@ -884,6 +899,7 @@
out_nosend:
/* release socket write lock before attempting to handle error */
xprt_abort_transmit(task);
+ rpc_task_force_reencode(task);
}
/*
@@ -915,7 +931,6 @@
break;
case -ECONNREFUSED:
case -ENOTCONN:
- req->rq_bytes_sent = 0;
if (clnt->cl_autobind)
clnt->cl_port = 0;
task->tk_action = call_bind;
@@ -937,7 +952,18 @@
}
/*
- * 6a. Handle RPC timeout
+ * 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
* We do not release the request slot, so we keep using the
* same XID for all retransmits.
*/
