Commit 17814819 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

SUNRPC: Fix call completion races with call_decode() 



We need to make sure that the req->rq_private_buf is completely up to
date before we make req->rq_reply_bytes_recvd visible to the
call_decode() routine in order to avoid triggering the WARN_ON().

Reported-by: default avatarBenjamin Coddington <bcodding@redhat.com>
Fixes: 72691a26 ("SUNRPC: Don't reuse bvec on retransmission of the request")
Tested-by: default avatarBenjamin Coddington <bcodding@redhat.com>
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
parent ed06fce0

net/sunrpc/xprt.c

+4 −4
Original line number Diff line number Diff line
@@ -1179,11 +1179,8 @@ xprt_request_dequeue_receive_locked(struct rpc_task *task) 
{

	struct rpc_rqst *req = task->tk_rqstp;



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

	if (test_and_clear_bit(RPC_TASK_NEED_RECV, &task->tk_runstate))

		xprt_request_rb_remove(req->rq_xprt, req);

		xdr_free_bvec(&req->rq_rcv_buf);

		req->rq_private_buf.bvec = NULL;

	}

}



/**
@@ -1221,6 +1218,8 @@ void xprt_complete_rqst(struct rpc_task *task, int copied) 


	xprt->stat.recvs++;



	xdr_free_bvec(&req->rq_rcv_buf);

	req->rq_private_buf.bvec = NULL;

	req->rq_private_buf.len = copied;

	/* Ensure all writes are done before we update */

	/* req->rq_reply_bytes_recvd */
@@ -1453,6 +1452,7 @@ xprt_request_dequeue_xprt(struct rpc_task *task) 
		xprt_request_dequeue_transmit_locked(task);

		xprt_request_dequeue_receive_locked(task);

		spin_unlock(&xprt->queue_lock);

		xdr_free_bvec(&req->rq_rcv_buf);

	}

}