On 01/06/2010 07:01 AM, J. Bruce Fields wrote:
On Thu, Dec 31, 2009 at 10:52:36AM +0800, Xiaotian Feng wrote: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.Signed-off-by: Xiaotian Feng<dfeng@xxxxxxxxxx> Cc: J. Bruce Fields<bfields@xxxxxxxxxxxx> Cc: Neil Brown<neilb@xxxxxxx> Cc: Trond Myklebust<Trond.Myklebust@xxxxxxxxxx> Cc: David S. Miller<davem@xxxxxxxxxxxxx> --- 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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