Commit 7f3a1d1e authored by Trond Myklebust's avatar Trond Myklebust
Browse files

SUNRPC: Refactor xprt_transmit() to remove wait for reply code 



Allow the caller in clnt.c to call into the code to wait for a reply
after calling xprt_transmit(). Again, the reason is that the backchannel
code does not need this functionality.

Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
parent edc81dcd

include/linux/sunrpc/xprt.h

+1 −0
Original line number Diff line number Diff line
@@ -335,6 +335,7 @@ void xprt_free_slot(struct rpc_xprt *xprt, 
void			xprt_lock_and_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);

bool			xprt_prepare_transmit(struct rpc_task *task);

void			xprt_request_enqueue_receive(struct rpc_task *task);

void			xprt_request_wait_receive(struct rpc_task *task);

void			xprt_transmit(struct rpc_task *task);

void			xprt_end_transmit(struct rpc_task *task);

int			xprt_adjust_timeout(struct rpc_rqst *req);

net/sunrpc/clnt.c

+1 −9
Original line number Diff line number Diff line
@@ -1975,15 +1975,6 @@ call_transmit(struct rpc_task *task) 
		return;

	if (is_retrans)

		task->tk_client->cl_stats->rpcretrans++;

	/*

	 * 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 (rpc_reply_expected(task))

		return;

	task->tk_action = rpc_exit_task;

	rpc_wake_up_queued_task(&task->tk_rqstp->rq_xprt->pending, task);

}



/*
@@ -2000,6 +1991,7 @@ call_transmit_status(struct rpc_task *task) 
	 */

	if (task->tk_status == 0) {

		xprt_end_transmit(task);

		xprt_request_wait_receive(task);

		return;

	}

net/sunrpc/xprt.c

+52 −22
Original line number Diff line number Diff line
@@ -654,6 +654,22 @@ void xprt_force_disconnect(struct rpc_xprt *xprt) 
}

EXPORT_SYMBOL_GPL(xprt_force_disconnect);



static unsigned int

xprt_connect_cookie(struct rpc_xprt *xprt)

{

	return READ_ONCE(xprt->connect_cookie);

}



static bool

xprt_request_retransmit_after_disconnect(struct rpc_task *task)

{

	struct rpc_rqst *req = task->tk_rqstp;

	struct rpc_xprt *xprt = req->rq_xprt;



	return req->rq_connect_cookie != xprt_connect_cookie(xprt) ||

		!xprt_connected(xprt);

}



/**

 * xprt_conditional_disconnect - force a transport to disconnect

 * @xprt: transport to disconnect
@@ -1009,6 +1025,39 @@ static void xprt_timer(struct rpc_task *task) 
		task->tk_status = 0;

}



/**

 * xprt_request_wait_receive - wait for the reply to an RPC request

 * @task: RPC task about to send a request

 *

 */

void xprt_request_wait_receive(struct rpc_task *task)

{

	struct rpc_rqst *req = task->tk_rqstp;

	struct rpc_xprt *xprt = req->rq_xprt;



	if (!test_bit(RPC_TASK_NEED_RECV, &task->tk_runstate))

		return;

	/*

	 * Sleep on the pending queue if we're expecting a reply.

	 * The spinlock ensures atomicity between the test of

	 * req->rq_reply_bytes_recvd, and the call to rpc_sleep_on().

	 */

	spin_lock(&xprt->queue_lock);

	if (test_bit(RPC_TASK_NEED_RECV, &task->tk_runstate)) {

		xprt->ops->set_retrans_timeout(task);

		rpc_sleep_on(&xprt->pending, task, xprt_timer);

		/*

		 * Send an extra queue wakeup call if the

		 * connection was dropped in case the call to

		 * rpc_sleep_on() raced.

		 */

		if (xprt_request_retransmit_after_disconnect(task))

			rpc_wake_up_queued_task_set_status(&xprt->pending,

					task, -ENOTCONN);

	}

	spin_unlock(&xprt->queue_lock);

}



/**

 * xprt_prepare_transmit - reserve the transport before sending a request

 * @task: RPC task about to send a request
@@ -1028,9 +1077,8 @@ bool xprt_prepare_transmit(struct rpc_task *task) 
			task->tk_status = req->rq_reply_bytes_recvd;

			goto out_unlock;

		}

		if ((task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT)

		    && xprt_connected(xprt)

		    && req->rq_connect_cookie == xprt->connect_cookie) {

		if ((task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) &&

		    !xprt_request_retransmit_after_disconnect(task)) {

			xprt->ops->set_retrans_timeout(task);

			rpc_sleep_on(&xprt->pending, task, xprt_timer);

			goto out_unlock;
@@ -1091,8 +1139,6 @@ void xprt_transmit(struct rpc_task *task) 
	task->tk_flags |= RPC_TASK_SENT;

	spin_lock_bh(&xprt->transport_lock);



	xprt->ops->set_retrans_timeout(task);



	xprt->stat.sends++;

	xprt->stat.req_u += xprt->stat.sends - xprt->stat.recvs;

	xprt->stat.bklog_u += xprt->backlog.qlen;
@@ -1101,22 +1147,6 @@ void xprt_transmit(struct rpc_task *task) 
	spin_unlock_bh(&xprt->transport_lock);



	req->rq_connect_cookie = connect_cookie;

	if (test_bit(RPC_TASK_NEED_RECV, &task->tk_runstate)) {

		/*

		 * Sleep on the pending queue if we're expecting a reply.

		 * The spinlock ensures atomicity between the test of

		 * req->rq_reply_bytes_recvd, and the call to rpc_sleep_on().

		 */

		spin_lock(&xprt->queue_lock);

		if (test_bit(RPC_TASK_NEED_RECV, &task->tk_runstate)) {

			rpc_sleep_on(&xprt->pending, task, xprt_timer);

			/* Wake up immediately if the connection was dropped */

			if (!xprt_connected(xprt))

				rpc_wake_up_queued_task_set_status(&xprt->pending,

						task, -ENOTCONN);

		}

		spin_unlock(&xprt->queue_lock);

	}

}



static void xprt_add_backlog(struct rpc_xprt *xprt, struct rpc_task *task)
@@ -1321,7 +1351,7 @@ xprt_request_init(struct rpc_task *task) 
	req->rq_xprt    = xprt;

	req->rq_buffer  = NULL;

	req->rq_xid	= xprt_alloc_xid(xprt);

	req->rq_connect_cookie = xprt->connect_cookie - 1;

	req->rq_connect_cookie = xprt_connect_cookie(xprt) - 1;

	req->rq_bytes_sent = 0;

	req->rq_snd_buf.len = 0;

	req->rq_snd_buf.buflen = 0;

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