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Commit 940e3318 authored by Trond Myklebust's avatar Trond Myklebust Committed by Linus Torvalds
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[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: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent e4d76e1c

net/sunrpc/clnt.c

+29 −3
Original line number Diff line number Diff line
@@ -55,6 +55,7 @@ static void call_bind(struct rpc_task *task); 
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 @@ call_allocate(struct rpc_task *task) 
	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 @@ call_transmit(struct rpc_task *task) 
	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 @@ call_transmit(struct rpc_task *task) 
out_nosend:

	/* release socket write lock before attempting to handle error */

	xprt_abort_transmit(task);

	rpc_task_force_reencode(task);

}



/*
@@ -915,7 +931,6 @@ call_status(struct rpc_task *task) 
		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 @@ call_status(struct rpc_task *task) 
}



/*

 * 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.

 */