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Commit e0ab53de authored by Trond Myklebust's avatar Trond Myklebust
Browse files

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: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
(cherry picked from 031a50c8b9ea82616abd4a4e18021a25848941ce commit)
parent f3d43c76

include/linux/sunrpc/xprt.h

+1 −1
Original line number Diff line number Diff line
@@ -229,7 +229,7 @@ int xprt_reserve_xprt(struct rpc_task *task); 
int			xprt_reserve_xprt_cong(struct rpc_task *task);

int			xprt_prepare_transmit(struct rpc_task *task);

void			xprt_transmit(struct rpc_task *task);

void			xprt_abort_transmit(struct rpc_task *task);

void			xprt_end_transmit(struct rpc_task *task);

int			xprt_adjust_timeout(struct rpc_rqst *req);

void			xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);

void			xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);

net/sunrpc/clnt.c

+29 −23
Original line number Diff line number Diff line
@@ -921,26 +921,43 @@ call_transmit(struct rpc_task *task) 
	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) {

	/*

	 * 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;

out_nosend:

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

	xprt_abort_transmit(task);

	xprt_end_transmit(task);

	rpc_task_force_reencode(task);

}
@@ -992,18 +1009,7 @@ call_status(struct rpc_task *task) 
}



/*

 * 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.

 */

net/sunrpc/xprt.c

+3 −18
Original line number Diff line number Diff line
@@ -707,12 +707,9 @@ int xprt_prepare_transmit(struct rpc_task *task) 
	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 @@ void xprt_transmit(struct rpc_task *task) 
			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 @@ void xprt_transmit(struct rpc_task *task) 
	 *	 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)

net/sunrpc/xprtsock.c

+28 −1
Original line number Diff line number Diff line
@@ -413,6 +413,33 @@ static int xs_tcp_send_request(struct rpc_task *task) 
	return status;

}



/**

 * 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_udp_ops = { 


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,