Commit 05a4b583 authored by Dai Ngo's avatar Dai Ngo Committed by Chuck Lever
Browse files

SUNRPC: remove printk when back channel request not found 



If the client interface is down, or there is a network partition between
the client and server that prevents the callback request to reach the
client, TCP on the server will keep re-transmitting the callback for about
~9 minutes before giving up and closing the connection.

If the connection between the client and the server is re-established
before the connection is closed and after the callback timed out (9 secs)
then the re-transmitted callback request will arrive at the client. When
the server receives the reply of the callback, receive_cb_reply prints the
"Got unrecognized reply..." message in the system log since the callback
request was already removed from the server xprt's recv_queue.

Even though this scenario has no effect on the server operation, a
malfunctioning or malicious client can fill up the server's system log.

Signed-off-by: default avatarDai Ngo <dai.ngo@oracle.com>
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
parent d3dba534

net/sunrpc/svcsock.c

+2 −12
Original line number Diff line number Diff line
@@ -1049,18 +1049,14 @@ static int receive_cb_reply(struct svc_sock *svsk, struct svc_rqst *rqstp) 
	struct rpc_rqst *req = NULL;

	struct kvec *src, *dst;

	__be32 *p = (__be32 *)rqstp->rq_arg.head[0].iov_base;

	__be32 xid;

	__be32 calldir;



	xid = *p++;

	calldir = *p;

	__be32 xid = *p;



	if (!bc_xprt)

		return -EAGAIN;

	spin_lock(&bc_xprt->queue_lock);

	req = xprt_lookup_rqst(bc_xprt, xid);

	if (!req)

		goto unlock_notfound;

		goto unlock_eagain;



	memcpy(&req->rq_private_buf, &req->rq_rcv_buf, sizeof(struct xdr_buf));

	/*
@@ -1077,12 +1073,6 @@ static int receive_cb_reply(struct svc_sock *svsk, struct svc_rqst *rqstp) 
	rqstp->rq_arg.len = 0;

	spin_unlock(&bc_xprt->queue_lock);

	return 0;

unlock_notfound:

	printk(KERN_NOTICE

		"%s: Got unrecognized reply: "

		"calldir 0x%x xpt_bc_xprt %p xid %08x\n",

		__func__, ntohl(calldir),

		bc_xprt, ntohl(xid));

unlock_eagain:

	spin_unlock(&bc_xprt->queue_lock);

	return -EAGAIN;