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From: Chuck Lever <chuck.lever@oracle.com>
To: bfields@fieldses.org
Cc: linux-nfs@vger.kernel.org, linux-rdma@vger.kernel.org
Subject: [PATCH v3 22/32] SUNRPC: Refactor recvfrom path dealing with incomplete TCP receives
Date: Thu, 21 May 2020 10:35:39 -0400
Message-ID: <20200521143539.3557.12371.stgit@klimt.1015granger.net> (raw)
In-Reply-To: <20200521141100.3557.17098.stgit@klimt.1015granger.net>

Clean up: move exception processing out of the main path.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 include/trace/events/sunrpc.h |   31 +++++++++++++++++++++++++++++++
 net/sunrpc/svcsock.c          |   39 +++++++++++++++++++--------------------
 2 files changed, 50 insertions(+), 20 deletions(-)

diff --git a/include/trace/events/sunrpc.h b/include/trace/events/sunrpc.h
index bfea554bd91f..81659876b4af 100644
--- a/include/trace/events/sunrpc.h
+++ b/include/trace/events/sunrpc.h
@@ -1503,9 +1503,40 @@ DECLARE_EVENT_CLASS(svcsock_class,
 DEFINE_SVCSOCK_EVENT(udp_send);
 DEFINE_SVCSOCK_EVENT(tcp_send);
 DEFINE_SVCSOCK_EVENT(tcp_recv);
+DEFINE_SVCSOCK_EVENT(tcp_recv_eagain);
+DEFINE_SVCSOCK_EVENT(tcp_recv_err);
 DEFINE_SVCSOCK_EVENT(data_ready);
 DEFINE_SVCSOCK_EVENT(write_space);
 
+TRACE_EVENT(svcsock_tcp_recv_short,
+	TP_PROTO(
+		const struct svc_xprt *xprt,
+		u32 expected,
+		u32 received
+	),
+
+	TP_ARGS(xprt, expected, received),
+
+	TP_STRUCT__entry(
+		__field(u32, expected)
+		__field(u32, received)
+		__field(unsigned long, flags)
+		__string(addr, xprt->xpt_remotebuf)
+	),
+
+	TP_fast_assign(
+		__entry->expected = expected;
+		__entry->received = received;
+		__entry->flags = xprt->xpt_flags;
+		__assign_str(addr, xprt->xpt_remotebuf);
+	),
+
+	TP_printk("addr=%s flags=%s expected=%u received=%u",
+		__get_str(addr), show_svc_xprt_flags(__entry->flags),
+		__entry->expected, __entry->received
+	)
+);
+
 TRACE_EVENT(svcsock_tcp_state,
 	TP_PROTO(
 		const struct svc_xprt *xprt,
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 8cf06b676831..087e21b0f1bb 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -968,23 +968,10 @@ static int svc_tcp_recvfrom(struct svc_rqst *rqstp)
 		svsk->sk_tcplen += len;
 		svsk->sk_datalen += len;
 	}
-	if (len != want || !svc_sock_final_rec(svsk)) {
-		svc_tcp_save_pages(svsk, rqstp);
-		if (len < 0 && len != -EAGAIN)
-			goto err_delete;
-		if (len == want)
-			svc_tcp_fragment_received(svsk);
-		else
-			dprintk("svc: incomplete TCP record (%d of %d)\n",
-				(int)(svsk->sk_tcplen - sizeof(rpc_fraghdr)),
-				svc_sock_reclen(svsk));
-		goto err_noclose;
-	}
-
-	if (svsk->sk_datalen < 8) {
-		svsk->sk_datalen = 0;
-		goto err_delete; /* client is nuts. */
-	}
+	if (len != want || !svc_sock_final_rec(svsk))
+		goto err_incomplete;
+	if (svsk->sk_datalen < 8)
+		goto err_nuts;
 
 	rqstp->rq_arg.len = svsk->sk_datalen;
 	rqstp->rq_arg.page_base = 0;
@@ -1019,14 +1006,26 @@ static int svc_tcp_recvfrom(struct svc_rqst *rqstp)
 
 	return rqstp->rq_arg.len;
 
+err_incomplete:
+	svc_tcp_save_pages(svsk, rqstp);
+	if (len < 0 && len != -EAGAIN)
+		goto err_delete;
+	if (len == want)
+		svc_tcp_fragment_received(svsk);
+	else
+		trace_svcsock_tcp_recv_short(&svsk->sk_xprt,
+				svc_sock_reclen(svsk),
+				svsk->sk_tcplen - sizeof(rpc_fraghdr));
+	goto err_noclose;
 error:
 	if (len != -EAGAIN)
 		goto err_delete;
-	dprintk("RPC: TCP recvfrom got EAGAIN\n");
+	trace_svcsock_tcp_recv_eagain(&svsk->sk_xprt, 0);
 	return 0;
+err_nuts:
+	svsk->sk_datalen = 0;
 err_delete:
-	printk(KERN_NOTICE "%s: recvfrom returned errno %d\n",
-	       svsk->sk_xprt.xpt_server->sv_name, -len);
+	trace_svcsock_tcp_recv_err(&svsk->sk_xprt, len);
 	set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);
 err_noclose:
 	return 0;	/* record not complete */


  parent reply index

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-21 14:33 [PATCH v3 00/32] Possible NFSD patches for v5.8 Chuck Lever
2020-05-21 14:33 ` [PATCH v3 01/32] SUNRPC: Move xpt_mutex into socket xpo_sendto methods Chuck Lever
2020-05-21 14:33 ` [PATCH v3 02/32] svcrdma: Clean up the tracing for rw_ctx_init errors Chuck Lever
2020-05-21 14:33 ` [PATCH v3 03/32] svcrdma: Clean up handling of get_rw_ctx errors Chuck Lever
2020-05-21 14:34 ` [PATCH v3 04/32] svcrdma: Trace page overruns when constructing RDMA Reads Chuck Lever
2020-05-21 14:34 ` [PATCH v3 05/32] svcrdma: trace undersized Write chunks Chuck Lever
2020-05-21 14:34 ` [PATCH v3 06/32] svcrdma: Fix backchannel return code Chuck Lever
2020-05-21 14:34 ` [PATCH v3 07/32] svcrdma: Remove backchannel dprintk call sites Chuck Lever
2020-05-21 14:34 ` [PATCH v3 08/32] svcrdma: Rename tracepoints that record header decoding errors Chuck Lever
2020-05-21 14:34 ` [PATCH v3 09/32] svcrdma: Remove the SVCRDMA_DEBUG macro Chuck Lever
2020-05-21 14:34 ` [PATCH v3 10/32] svcrdma: Displayed remote IP address should match stored address Chuck Lever
2020-05-21 14:34 ` [PATCH v3 11/32] svcrdma: Add tracepoints to report ->xpo_accept failures Chuck Lever
2020-05-21 14:34 ` [PATCH v3 12/32] SUNRPC: Remove kernel memory address from svc_xprt tracepoints Chuck Lever
2020-05-21 14:34 ` [PATCH v3 13/32] SUNRPC: Tracepoint to record errors in svc_xpo_create() Chuck Lever
2020-05-21 14:34 ` [PATCH v3 14/32] SUNRPC: Trace a few more generic svc_xprt events Chuck Lever
2020-05-21 14:35 ` [PATCH v3 15/32] SUNRPC: Remove "#include <trace/events/skb.h>" Chuck Lever
2020-05-21 14:35 ` [PATCH v3 16/32] SUNRPC: Add more svcsock tracepoints Chuck Lever
2020-05-21 14:35 ` [PATCH v3 17/32] SUNRPC: Replace dprintk call sites in TCP state change callouts Chuck Lever
2020-05-21 14:35 ` [PATCH v3 18/32] SUNRPC: Trace server-side rpcbind registration events Chuck Lever
2020-05-21 14:35 ` [PATCH v3 19/32] SUNRPC: Rename svc_sock::sk_reclen Chuck Lever
2020-05-21 14:35 ` [PATCH v3 20/32] SUNRPC: Restructure svc_tcp_recv_record() Chuck Lever
2020-05-21 14:35 ` [PATCH v3 21/32] SUNRPC: Replace dprintk() call sites in TCP receive path Chuck Lever
2020-05-21 14:35 ` Chuck Lever [this message]
2020-05-21 14:35 ` [PATCH v3 23/32] SUNRPC: Clean up svc_release_skb() functions Chuck Lever
2020-05-21 14:35 ` [PATCH v3 24/32] SUNRPC: Refactor svc_recvfrom() Chuck Lever
2020-05-21 14:35 ` [PATCH v3 25/32] SUNRPC: Restructure svc_udp_recvfrom() Chuck Lever
2020-05-21 14:36 ` [PATCH v3 26/32] SUNRPC: svc_show_status() macro should have enum definitions Chuck Lever
2020-05-21 14:36 ` [PATCH v3 27/32] NFSD: Add tracepoints to NFSD's duplicate reply cache Chuck Lever
2020-05-21 14:36 ` [PATCH v3 28/32] NFSD: Add tracepoints to the NFSD state management code Chuck Lever
2020-05-21 14:36 ` [PATCH v3 29/32] NFSD: Add tracepoints for monitoring NFSD callbacks Chuck Lever
2020-05-21 14:36 ` [PATCH v3 30/32] SUNRPC: Clean up request deferral tracepoints Chuck Lever
2020-05-21 14:36 ` [PATCH v3 31/32] NFSD: Squash an annoying compiler warning Chuck Lever
2020-05-21 14:36 ` [PATCH v3 32/32] NFSD: Fix improperly-formatted Doxygen comments Chuck Lever

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