On 01/06/2010 07:01 AM, J. Bruce Fields wrote:

On Thu, Dec 31, 2009 at 10:52:36AM +0800, Xiaotian Feng wrote:

quoted

There're some warnings of "nfsd: peername failed (err 107)!"
socket error -107 means Transport endpoint is not connected.
This warning message was outputed by svc_tcp_accept() [net/sunrpc/svcsock.c],
when kernel_getpeername returns -107. This means socket might be CLOSED.

And svc_tcp_accept was called by svc_recv() [net/sunrpc/svc_xprt.c]

         if (test_bit(XPT_LISTENER,&xprt->xpt_flags)) {
         <snip>
                 newxpt = xprt->xpt_ops->xpo_accept(xprt);
         <snip>

So this might happen when xprt->xpt_flags has both XPT_LISTENER and XPT_CLOSE.

Let's take a look at commit b0401d72, this commit has moved the close
processing after do recvfrom method, but this commit also introduces this
warnings, if the xpt_flags has both XPT_LISTENER and XPT_CLOSED, we should
close it, not accpet then close.

The logic here seems unnecessarily complicated now, but as a minimal
fix, this seems fine.

Is the *only* justification for this to silence this warning, or is
there some more serious problem I'm missing?

If a xprt->xpt_flags has XPT_CLOSE & XPT_LISTENER, kernel will accept it 
first,
and svc_xprt_received(xptr) no mater xpo_accept is suceed or failed, 
then svc_delete_xprt(xprt).

I'm not sure what will happened between the svc_xprt_received and 
svc_delete_xprt, there isn't any
lock to protect it.

--b.

quoted

Signed-off-by: Xiaotian Feng<redacted>
Cc: J. Bruce Fields<redacted>
Cc: Neil Brown<redacted>
Cc: Trond Myklebust<redacted>
Cc: David S. Miller<davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
---

diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index 1c924ee..187f0f4 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c

@@ -699,7 +699,8 @@ int svc_recv(struct svc_rqst *rqstp, long timeout)
  	spin_unlock_bh(&pool->sp_lock);

  	len = 0;
-	if (test_bit(XPT_LISTENER,&xprt->xpt_flags)) {
+	if (test_bit(XPT_LISTENER,&xprt->xpt_flags)&&
+	    !test_bit(XPT_CLOSE,&xprt->xpt_flags)) {
  		struct svc_xprt *newxpt;
  		newxpt = xprt->xpt_ops->xpo_accept(xprt);
  		if (newxpt) {

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