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: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 998687421fa6af39ea1a9a9326a87544d0c2c950..bfb2f78523a8289f0a6ea758ca61c53d06832273 100644 (file)
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -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;