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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 25/32] SUNRPC: Restructure svc_udp_recvfrom()
Date: Thu, 21 May 2020 10:35:55 -0400
Message-ID: <20200521143555.3557.78504.stgit@klimt.1015granger.net> (raw)
In-Reply-To: <20200521141100.3557.17098.stgit@klimt.1015granger.net>

Clean up. At this point, we are not ready yet to support bio_vecs in
the UDP transport implementation. However, we can clean up
svc_udp_recvfrom() to match the tracing and straight-lining recently
changes made in svc_tcp_recvfrom().

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 include/trace/events/sunrpc.h |    2 +
 net/sunrpc/svcsock.c          |   60 ++++++++++++++++++++++++-----------------
 2 files changed, 37 insertions(+), 25 deletions(-)

diff --git a/include/trace/events/sunrpc.h b/include/trace/events/sunrpc.h
index 81659876b4af..08c7d618ceb4 100644
--- a/include/trace/events/sunrpc.h
+++ b/include/trace/events/sunrpc.h
@@ -1501,6 +1501,8 @@ DECLARE_EVENT_CLASS(svcsock_class,
 			TP_ARGS(xprt, result))
 
 DEFINE_SVCSOCK_EVENT(udp_send);
+DEFINE_SVCSOCK_EVENT(udp_recv);
+DEFINE_SVCSOCK_EVENT(udp_recv_err);
 DEFINE_SVCSOCK_EVENT(tcp_send);
 DEFINE_SVCSOCK_EVENT(tcp_recv);
 DEFINE_SVCSOCK_EVENT(tcp_recv_eagain);
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 3e25511b800e..97d2b6f8c791 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -425,8 +425,15 @@ static int svc_udp_get_dest_address(struct svc_rqst *rqstp,
 	return 0;
 }
 
-/*
- * Receive a datagram from a UDP socket.
+/**
+ * svc_udp_recvfrom - Receive a datagram from a UDP socket.
+ * @rqstp: request structure into which to receive an RPC Call
+ *
+ * Called in a loop when XPT_DATA has been set.
+ *
+ * Returns:
+ *   On success, the number of bytes in a received RPC Call, or
+ *   %0 if a complete RPC Call message was not ready to return
  */
 static int svc_udp_recvfrom(struct svc_rqst *rqstp)
 {
@@ -460,20 +467,14 @@ static int svc_udp_recvfrom(struct svc_rqst *rqstp)
 	    svc_sock_setbufsize(svsk, serv->sv_nrthreads + 3);
 
 	clear_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
-	skb = NULL;
 	err = kernel_recvmsg(svsk->sk_sock, &msg, NULL,
 			     0, 0, MSG_PEEK | MSG_DONTWAIT);
-	if (err >= 0)
-		skb = skb_recv_udp(svsk->sk_sk, 0, 1, &err);
-
-	if (skb == NULL) {
-		if (err != -EAGAIN) {
-			/* possibly an icmp error */
-			dprintk("svc: recvfrom returned error %d\n", -err);
-			set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
-		}
-		return 0;
-	}
+	if (err < 0)
+		goto out_recv_err;
+	skb = skb_recv_udp(svsk->sk_sk, 0, 1, &err);
+	if (!skb)
+		goto out_recv_err;
+
 	len = svc_addr_len(svc_addr(rqstp));
 	rqstp->rq_addrlen = len;
 	if (skb->tstamp == 0) {
@@ -484,26 +485,21 @@ static int svc_udp_recvfrom(struct svc_rqst *rqstp)
 	sock_write_timestamp(svsk->sk_sk, skb->tstamp);
 	set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags); /* there may be more data... */
 
-	len  = skb->len;
+	len = skb->len;
 	rqstp->rq_arg.len = len;
+	trace_svcsock_udp_recv(&svsk->sk_xprt, len);
 
 	rqstp->rq_prot = IPPROTO_UDP;
 
-	if (!svc_udp_get_dest_address(rqstp, cmh)) {
-		net_warn_ratelimited("svc: received unknown control message %d/%d; dropping RPC reply datagram\n",
-				     cmh->cmsg_level, cmh->cmsg_type);
-		goto out_free;
-	}
+	if (!svc_udp_get_dest_address(rqstp, cmh))
+		goto out_cmsg_err;
 	rqstp->rq_daddrlen = svc_addr_len(svc_daddr(rqstp));
 
 	if (skb_is_nonlinear(skb)) {
 		/* we have to copy */
 		local_bh_disable();
-		if (csum_partial_copy_to_xdr(&rqstp->rq_arg, skb)) {
-			local_bh_enable();
-			/* checksum error */
-			goto out_free;
-		}
+		if (csum_partial_copy_to_xdr(&rqstp->rq_arg, skb))
+			goto out_bh_enable;
 		local_bh_enable();
 		consume_skb(skb);
 	} else {
@@ -531,6 +527,20 @@ static int svc_udp_recvfrom(struct svc_rqst *rqstp)
 		serv->sv_stats->netudpcnt++;
 
 	return len;
+
+out_recv_err:
+	if (err != -EAGAIN) {
+		/* possibly an icmp error */
+		set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
+	}
+	trace_svcsock_udp_recv_err(&svsk->sk_xprt, err);
+	return 0;
+out_cmsg_err:
+	net_warn_ratelimited("svc: received unknown control message %d/%d; dropping RPC reply datagram\n",
+			     cmh->cmsg_level, cmh->cmsg_type);
+	goto out_free;
+out_bh_enable:
+	local_bh_enable();
 out_free:
 	kfree_skb(skb);
 	return 0;


  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 ` [PATCH v3 22/32] SUNRPC: Refactor recvfrom path dealing with incomplete TCP receives Chuck Lever
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 ` Chuck Lever [this message]
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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