[PATCH RFC 0/3] Prepare NFS server for RPC-on-TLS

[PATCH RFC 0/3] Prepare NFS server for RPC-on-TLS

[Chuck Lever]

The following series implements changes to the Linux NFS server's
socket transport that are pre-requisite to supporting RPC on TLS.
The socket transport is made to use the iov_iter-based kernel
socket APIs. These changes are modeled after similar changes made
to the NFS client-side socket transport.

This is a draft patch series. I have tried it out and it is working,
but as it has changed only the Reply-send side, it is incomplete.
This posting is a request for comments -- show your work.

One additional change I might make in this series is moving the
xpt_mutex into the socket sendto methods. This is because the
RDMA sendto method doesn't appear to require serialization. That
is still down the road.


---

Chuck Lever (3):
      SUNRPC: Move xs_stream_record_marker
      SUNRPC: Refactor xs_sendpages()
      SUNRPC: Teach server to use xprt_sock_sendmsg for socket sends


 include/linux/sunrpc/msg_prot.h |   13 ++
 include/linux/sunrpc/svcauth.h  |    1 
 include/linux/sunrpc/xdr.h      |   14 ---
 net/sunrpc/socklib.c            |  136 ++++++++++++++++++++++++++
 net/sunrpc/socklib.h            |   15 +++
 net/sunrpc/sunrpc.h             |    4 -
 net/sunrpc/svc.c                |    4 -
 net/sunrpc/svcsock.c            |  203 +++++++++++++--------------------------
 net/sunrpc/xprtsock.c           |  203 ++++++---------------------------------
 9 files changed, 261 insertions(+), 332 deletions(-)
 create mode 100644 net/sunrpc/socklib.h

--
Chuck Lever

[PATCH RFC 1/3] SUNRPC: Move xs_stream_record_marker

[Chuck Lever]

Refactor: Allow the client and server to share this helper function.

msg_prot.h now needs linux/kernel.h for cpu_to_be32. #include
<msg_prot.h> is removed anywhere it is not required and causes a
compilation failure due to the new header dependency.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 include/linux/sunrpc/msg_prot.h |   13 +++++++++++++
 include/linux/sunrpc/svcauth.h  |    1 -
 net/sunrpc/xprtsock.c           |   18 +++---------------
 3 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/include/linux/sunrpc/msg_prot.h b/include/linux/sunrpc/msg_prot.h
index bea40d9f03a1..cceb5a3e39f5 100644
--- a/include/linux/sunrpc/msg_prot.h
+++ b/include/linux/sunrpc/msg_prot.h
@@ -104,6 +104,19 @@ enum rpc_auth_stat {
 #define	RPC_FRAGMENT_SIZE_MASK		(~RPC_LAST_STREAM_FRAGMENT)
 #define	RPC_MAX_FRAGMENT_SIZE		((1U << 31) - 1)
 
+/**
+ * rpc_stream_record_marker - Construct a 4-octet stream record marker
+ * @size: number of octets in the RPC message to send
+ *
+ * Returns the stream record marker field for a record of length < 2^31-1
+ */
+static inline rpc_fraghdr rpc_stream_record_marker(u32 size)
+{
+	if (!size)
+		return 0;
+	return cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | size);
+}
+
 /*
  * RPC call and reply header size as number of 32bit words (verifier
  * size computed separately, see below)
diff --git a/include/linux/sunrpc/svcauth.h b/include/linux/sunrpc/svcauth.h
index b0003866a249..aeac5a955cce 100644
--- a/include/linux/sunrpc/svcauth.h
+++ b/include/linux/sunrpc/svcauth.h
@@ -11,7 +11,6 @@
 #define _LINUX_SUNRPC_SVCAUTH_H_
 
 #include <linux/string.h>
-#include <linux/sunrpc/msg_prot.h>
 #include <linux/sunrpc/cache.h>
 #include <linux/sunrpc/gss_api.h>
 #include <linux/hash.h>
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index d86c664ea6af..f940179db510 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -929,17 +929,6 @@ static int xs_nospace(struct rpc_rqst *req)
 	return transport->xmit.offset != 0 && req->rq_bytes_sent == 0;
 }
 
-/*
- * Return the stream record marker field for a record of length < 2^31-1
- */
-static rpc_fraghdr
-xs_stream_record_marker(struct xdr_buf *xdr)
-{
-	if (!xdr->len)
-		return 0;
-	return cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | (u32)xdr->len);
-}
-
 /**
  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
  * @req: pointer to RPC request
@@ -957,7 +946,7 @@ static int xs_local_send_request(struct rpc_rqst *req)
 	struct sock_xprt *transport =
 				container_of(xprt, struct sock_xprt, xprt);
 	struct xdr_buf *xdr = &req->rq_snd_buf;
-	rpc_fraghdr rm = xs_stream_record_marker(xdr);
+	rpc_fraghdr rm = rpc_stream_record_marker(xdr->len);
 	unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
 	int status;
 	int sent = 0;
@@ -1104,7 +1093,7 @@ static int xs_tcp_send_request(struct rpc_rqst *req)
 	struct rpc_xprt *xprt = req->rq_xprt;
 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 	struct xdr_buf *xdr = &req->rq_snd_buf;
-	rpc_fraghdr rm = xs_stream_record_marker(xdr);
+	rpc_fraghdr rm = rpc_stream_record_marker(xdr->len);
 	unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
 	bool vm_wait = false;
 	int status;
@@ -2652,8 +2641,7 @@ static int bc_sendto(struct rpc_rqst *req)
 	struct msghdr msg = {
 		.msg_flags	= MSG_MORE
 	};
-	rpc_fraghdr marker = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT |
-					 (u32)xbufp->len);
+	rpc_fraghdr marker = rpc_stream_record_marker(xbufp->len);
 	struct kvec iov = {
 		.iov_base	= &marker,
 		.iov_len	= sizeof(marker),

[PATCH RFC 2/3] SUNRPC: Refactor xs_sendpages()

[Chuck Lever]

Refactor: Re-locate xs_sendpages() so that it can be shared with
server code.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 include/linux/sunrpc/xdr.h |   14 ----
 net/sunrpc/socklib.c       |  136 ++++++++++++++++++++++++++++++++++++++++
 net/sunrpc/socklib.h       |   15 ++++
 net/sunrpc/svcsock.c       |    1 
 net/sunrpc/xprtsock.c      |  148 ++++++--------------------------------------
 5 files changed, 172 insertions(+), 142 deletions(-)
 create mode 100644 net/sunrpc/socklib.h

diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h
index b41f34977995..a1264b19b34c 100644
--- a/include/linux/sunrpc/xdr.h
+++ b/include/linux/sunrpc/xdr.h
@@ -188,20 +188,6 @@ static inline void xdr_netobj_dup(struct xdr_netobj *dst,
 extern int read_bytes_from_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);
 extern int write_bytes_to_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);
 
-/*
- * Helper structure for copying from an sk_buff.
- */
-struct xdr_skb_reader {
-	struct sk_buff	*skb;
-	unsigned int	offset;
-	size_t		count;
-	__wsum		csum;
-};
-
-typedef size_t (*xdr_skb_read_actor)(struct xdr_skb_reader *desc, void *to, size_t len);
-
-extern int csum_partial_copy_to_xdr(struct xdr_buf *, struct sk_buff *);
-
 extern int xdr_encode_word(struct xdr_buf *, unsigned int, u32);
 extern int xdr_decode_word(struct xdr_buf *, unsigned int, u32 *);
 
diff --git a/net/sunrpc/socklib.c b/net/sunrpc/socklib.c
index 1a864f1ed119..7ccc83046af5 100644
--- a/net/sunrpc/socklib.c
+++ b/net/sunrpc/socklib.c
@@ -14,9 +14,24 @@
 #include <linux/types.h>
 #include <linux/pagemap.h>
 #include <linux/udp.h>
+#include <linux/sunrpc/msg_prot.h>
 #include <linux/sunrpc/xdr.h>
 #include <linux/export.h>
 
+#include "socklib.h"
+
+/*
+ * Helper structure for copying from an sk_buff.
+ */
+struct xdr_skb_reader {
+	struct sk_buff	*skb;
+	unsigned int	offset;
+	size_t		count;
+	__wsum		csum;
+};
+
+typedef size_t (*xdr_skb_read_actor)(struct xdr_skb_reader *desc, void *to,
+				     size_t len);
 
 /**
  * xdr_skb_read_bits - copy some data bits from skb to internal buffer
@@ -186,3 +201,124 @@ int csum_partial_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
 	return 0;
 }
 EXPORT_SYMBOL_GPL(csum_partial_copy_to_xdr);
+
+static inline int xprt_sendmsg(struct socket *sock, struct msghdr *msg,
+			       size_t seek)
+{
+	if (seek)
+		iov_iter_advance(&msg->msg_iter, seek);
+	return sock_sendmsg(sock, msg);
+}
+
+static int xprt_send_kvec(struct socket *sock, struct msghdr *msg,
+			  struct kvec *vec, size_t seek)
+{
+	iov_iter_kvec(&msg->msg_iter, WRITE, vec, 1, vec->iov_len);
+	return xprt_sendmsg(sock, msg, seek);
+}
+
+static int xprt_send_pagedata(struct socket *sock, struct msghdr *msg,
+			      struct xdr_buf *xdr, size_t base)
+{
+	int err;
+
+	err = xdr_alloc_bvec(xdr, GFP_KERNEL);
+	if (err < 0)
+		return err;
+
+	iov_iter_bvec(&msg->msg_iter, WRITE, xdr->bvec,
+			xdr_buf_pagecount(xdr),
+			xdr->page_len + xdr->page_base);
+	return xprt_sendmsg(sock, msg, base + xdr->page_base);
+}
+
+/* Common case:
+ *  - stream transport
+ *  - sending from byte 0 of the message
+ *  - the message is wholly contained in @xdr's head iovec
+ */
+static int xprt_send_rm_and_kvec(struct socket *sock, struct msghdr *msg,
+				 rpc_fraghdr marker, struct kvec *vec,
+				 size_t base)
+{
+	struct kvec iov[2] = {
+		[0] = {
+			.iov_base	= &marker,
+			.iov_len	= sizeof(marker)
+		},
+		[1] = *vec,
+	};
+	size_t len = iov[0].iov_len + iov[1].iov_len;
+
+	iov_iter_kvec(&msg->msg_iter, WRITE, iov, 2, len);
+	return xprt_sendmsg(sock, msg, base);
+}
+
+/**
+ * xprt_sock_sendmsg - write an xdr_buf directly to a socket
+ * @sock: open socket to send on
+ * @msg: socket message metadata
+ * @xdr: xdr_buf containing this request
+ * @base: starting position in the buffer
+ * @marker: stream record marker field
+ * @sent_p: return the total number of bytes successfully queued for sending
+ *
+ * Return values:
+ *   On success, returns zero and fills in @sent_p.
+ *   %-ENOTSOCK if  @sock is not a struct socket.
+ */
+int xprt_sock_sendmsg(struct socket *sock, struct msghdr *msg,
+		      struct xdr_buf *xdr, unsigned int base,
+		      rpc_fraghdr marker, unsigned int *sent_p)
+{
+	unsigned int rmsize = marker ? sizeof(marker) : 0;
+	unsigned int remainder = rmsize + xdr->len - base;
+	unsigned int want;
+	int err = 0;
+
+	if (unlikely(!sock))
+		return -ENOTSOCK;
+
+	msg->msg_flags |= MSG_MORE;
+	want = xdr->head[0].iov_len + rmsize;
+	if (base < want) {
+		unsigned int len = want - base;
+		remainder -= len;
+		if (remainder == 0)
+			msg->msg_flags &= ~MSG_MORE;
+		if (rmsize)
+			err = xprt_send_rm_and_kvec(sock, msg, marker,
+						    &xdr->head[0], base);
+		else
+			err = xprt_send_kvec(sock, msg, &xdr->head[0], base);
+		if (remainder == 0 || err != len)
+			goto out;
+		*sent_p += err;
+		base = 0;
+	} else
+		base -= want;
+
+	if (base < xdr->page_len) {
+		unsigned int len = xdr->page_len - base;
+		remainder -= len;
+		if (remainder == 0)
+			msg->msg_flags &= ~MSG_MORE;
+		err = xprt_send_pagedata(sock, msg, xdr, base);
+		if (remainder == 0 || err != len)
+			goto out;
+		*sent_p += err;
+		base = 0;
+	} else
+		base -= xdr->page_len;
+
+	if (base >= xdr->tail[0].iov_len)
+		return 0;
+	msg->msg_flags &= ~MSG_MORE;
+	err = xprt_send_kvec(sock, msg, &xdr->tail[0], base);
+out:
+	if (err > 0) {
+		*sent_p += err;
+		err = 0;
+	}
+	return err;
+}
diff --git a/net/sunrpc/socklib.h b/net/sunrpc/socklib.h
new file mode 100644
index 000000000000..c48114ad6f00
--- /dev/null
+++ b/net/sunrpc/socklib.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 1995-1997 Olaf Kirch <okir@monad.swb.de>
+ * Copyright (C) 2020, Oracle.
+ */
+
+#ifndef _NET_SUNRPC_SOCKLIB_H_
+#define _NET_SUNRPC_SOCKLIB_H_
+
+int csum_partial_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb);
+int xprt_sock_sendmsg(struct socket *sock, struct msghdr *msg,
+		      struct xdr_buf *xdr, unsigned int base,
+		      rpc_fraghdr marker, unsigned int *sent_p);
+
+#endif /* _NET_SUNRPC_SOCKLIB_H_ */
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index fe045b3e7e08..47957088d7d3 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -55,6 +55,7 @@
 #include <linux/sunrpc/stats.h>
 #include <linux/sunrpc/xprt.h>
 
+#include "socklib.h"
 #include "sunrpc.h"
 
 #define RPCDBG_FACILITY	RPCDBG_SVCXPRT
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index f940179db510..0380d72d8485 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -54,6 +54,7 @@
 
 #include <trace/events/sunrpc.h>
 
+#include "socklib.h"
 #include "sunrpc.h"
 
 static void xs_close(struct rpc_xprt *xprt);
@@ -749,125 +750,6 @@ static void xs_stream_data_receive_workfn(struct work_struct *work)
 
 #define XS_SENDMSG_FLAGS	(MSG_DONTWAIT | MSG_NOSIGNAL)
 
-static int xs_sendmsg(struct socket *sock, struct msghdr *msg, size_t seek)
-{
-	if (seek)
-		iov_iter_advance(&msg->msg_iter, seek);
-	return sock_sendmsg(sock, msg);
-}
-
-static int xs_send_kvec(struct socket *sock, struct msghdr *msg, struct kvec *vec, size_t seek)
-{
-	iov_iter_kvec(&msg->msg_iter, WRITE, vec, 1, vec->iov_len);
-	return xs_sendmsg(sock, msg, seek);
-}
-
-static int xs_send_pagedata(struct socket *sock, struct msghdr *msg, struct xdr_buf *xdr, size_t base)
-{
-	int err;
-
-	err = xdr_alloc_bvec(xdr, GFP_KERNEL);
-	if (err < 0)
-		return err;
-
-	iov_iter_bvec(&msg->msg_iter, WRITE, xdr->bvec,
-			xdr_buf_pagecount(xdr),
-			xdr->page_len + xdr->page_base);
-	return xs_sendmsg(sock, msg, base + xdr->page_base);
-}
-
-#define xs_record_marker_len() sizeof(rpc_fraghdr)
-
-/* Common case:
- *  - stream transport
- *  - sending from byte 0 of the message
- *  - the message is wholly contained in @xdr's head iovec
- */
-static int xs_send_rm_and_kvec(struct socket *sock, struct msghdr *msg,
-		rpc_fraghdr marker, struct kvec *vec, size_t base)
-{
-	struct kvec iov[2] = {
-		[0] = {
-			.iov_base	= &marker,
-			.iov_len	= sizeof(marker)
-		},
-		[1] = *vec,
-	};
-	size_t len = iov[0].iov_len + iov[1].iov_len;
-
-	iov_iter_kvec(&msg->msg_iter, WRITE, iov, 2, len);
-	return xs_sendmsg(sock, msg, base);
-}
-
-/**
- * xs_sendpages - write pages directly to a socket
- * @sock: socket to send on
- * @addr: UDP only -- address of destination
- * @addrlen: UDP only -- length of destination address
- * @xdr: buffer containing this request
- * @base: starting position in the buffer
- * @rm: stream record marker field
- * @sent_p: return the total number of bytes successfully queued for sending
- *
- */
-static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base, rpc_fraghdr rm, int *sent_p)
-{
-	struct msghdr msg = {
-		.msg_name = addr,
-		.msg_namelen = addrlen,
-		.msg_flags = XS_SENDMSG_FLAGS | MSG_MORE,
-	};
-	unsigned int rmsize = rm ? sizeof(rm) : 0;
-	unsigned int remainder = rmsize + xdr->len - base;
-	unsigned int want;
-	int err = 0;
-
-	if (unlikely(!sock))
-		return -ENOTSOCK;
-
-	want = xdr->head[0].iov_len + rmsize;
-	if (base < want) {
-		unsigned int len = want - base;
-		remainder -= len;
-		if (remainder == 0)
-			msg.msg_flags &= ~MSG_MORE;
-		if (rmsize)
-			err = xs_send_rm_and_kvec(sock, &msg, rm,
-					&xdr->head[0], base);
-		else
-			err = xs_send_kvec(sock, &msg, &xdr->head[0], base);
-		if (remainder == 0 || err != len)
-			goto out;
-		*sent_p += err;
-		base = 0;
-	} else
-		base -= want;
-
-	if (base < xdr->page_len) {
-		unsigned int len = xdr->page_len - base;
-		remainder -= len;
-		if (remainder == 0)
-			msg.msg_flags &= ~MSG_MORE;
-		err = xs_send_pagedata(sock, &msg, xdr, base);
-		if (remainder == 0 || err != len)
-			goto out;
-		*sent_p += err;
-		base = 0;
-	} else
-		base -= xdr->page_len;
-
-	if (base >= xdr->tail[0].iov_len)
-		return 0;
-	msg.msg_flags &= ~MSG_MORE;
-	err = xs_send_kvec(sock, &msg, &xdr->tail[0], base);
-out:
-	if (err > 0) {
-		*sent_p += err;
-		err = 0;
-	}
-	return err;
-}
-
 /**
  * xs_nospace - handle transmit was incomplete
  * @req: pointer to RPC request
@@ -948,8 +830,11 @@ static int xs_local_send_request(struct rpc_rqst *req)
 	struct xdr_buf *xdr = &req->rq_snd_buf;
 	rpc_fraghdr rm = rpc_stream_record_marker(xdr->len);
 	unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
+	struct msghdr msg = {
+		.msg_flags	= XS_SENDMSG_FLAGS,
+	};
+	unsigned int sent = 0;
 	int status;
-	int sent = 0;
 
 	/* Close the stream if the previous transmission was incomplete */
 	if (xs_send_request_was_aborted(transport, req)) {
@@ -961,8 +846,8 @@ static int xs_local_send_request(struct rpc_rqst *req)
 			req->rq_svec->iov_base, req->rq_svec->iov_len);
 
 	req->rq_xtime = ktime_get();
-	status = xs_sendpages(transport->sock, NULL, 0, xdr,
-			      transport->xmit.offset, rm, &sent);
+	status = xprt_sock_sendmsg(transport->sock, &msg, xdr,
+				   transport->xmit.offset, rm, &sent);
 	dprintk("RPC:       %s(%u) = %d\n",
 			__func__, xdr->len - transport->xmit.offset, status);
 
@@ -1014,7 +899,12 @@ static int xs_udp_send_request(struct rpc_rqst *req)
 	struct rpc_xprt *xprt = req->rq_xprt;
 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 	struct xdr_buf *xdr = &req->rq_snd_buf;
-	int sent = 0;
+	struct msghdr msg = {
+		.msg_name	= xs_addr(xprt),
+		.msg_namelen	= xprt->addrlen,
+		.msg_flags	= XS_SENDMSG_FLAGS,
+	};
+	unsigned int sent = 0;
 	int status;
 
 	xs_pktdump("packet data:",
@@ -1028,8 +918,7 @@ static int xs_udp_send_request(struct rpc_rqst *req)
 		return -EBADSLT;
 
 	req->rq_xtime = ktime_get();
-	status = xs_sendpages(transport->sock, xs_addr(xprt), xprt->addrlen,
-			      xdr, 0, 0, &sent);
+	status = xprt_sock_sendmsg(transport->sock, &msg, xdr, 0, 0, &sent);
 
 	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
 			xdr->len, status);
@@ -1095,9 +984,12 @@ static int xs_tcp_send_request(struct rpc_rqst *req)
 	struct xdr_buf *xdr = &req->rq_snd_buf;
 	rpc_fraghdr rm = rpc_stream_record_marker(xdr->len);
 	unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
+	struct msghdr msg = {
+		.msg_flags	= XS_SENDMSG_FLAGS,
+	};
 	bool vm_wait = false;
+	unsigned int sent;
 	int status;
-	int sent;
 
 	/* Close the stream if the previous transmission was incomplete */
 	if (xs_send_request_was_aborted(transport, req)) {
@@ -1119,8 +1011,8 @@ static int xs_tcp_send_request(struct rpc_rqst *req)
 	req->rq_xtime = ktime_get();
 	while (1) {
 		sent = 0;
-		status = xs_sendpages(transport->sock, NULL, 0, xdr,
-				      transport->xmit.offset, rm, &sent);
+		status = xprt_sock_sendmsg(transport->sock, &msg, xdr,
+					   transport->xmit.offset, rm, &sent);
 
 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
 				xdr->len - transport->xmit.offset, status);

[PATCH RFC 3/3] SUNRPC: Teach server to use xprt_sock_sendmsg for socket sends

[Chuck Lever]

xprt_sock_sendmsg uses the more efficient iov_iter-enabled kernel
socket API, and is a pre-requisite for server send-side support for
TLS.

Note that svc_process no longer needs to reserve a word for the
stream record marker, since the TCP transport now provides the
record marker automatically in a separate buffer.

The dprintk() in svc_send_common is also removed. It didn't seem
crucial for field troubleshooting. If more is needed there, a trace
point could be added in xprt_sock_sendmsg().

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 net/sunrpc/sunrpc.h   |    4 -
 net/sunrpc/svc.c      |    4 -
 net/sunrpc/svcsock.c  |  202 ++++++++++++++++---------------------------------
 net/sunrpc/xprtsock.c |   39 ++-------
 4 files changed, 74 insertions(+), 175 deletions(-)

diff --git a/net/sunrpc/sunrpc.h b/net/sunrpc/sunrpc.h
index c9bacb3c930f..47a756503d11 100644
--- a/net/sunrpc/sunrpc.h
+++ b/net/sunrpc/sunrpc.h
@@ -50,10 +50,6 @@ static inline int sock_is_loopback(struct sock *sk)
 	return loopback;
 }
 
-int svc_send_common(struct socket *sock, struct xdr_buf *xdr,
-		    struct page *headpage, unsigned long headoffset,
-		    struct page *tailpage, unsigned long tailoffset);
-
 int rpc_clients_notifier_register(void);
 void rpc_clients_notifier_unregister(void);
 #endif /* _NET_SUNRPC_SUNRPC_H */
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index d4a0134f1ca1..73b536cdb818 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -1529,10 +1529,6 @@ static __printf(2,3) void svc_printk(struct svc_rqst *rqstp, const char *fmt, ..
 		goto out_drop;
 	}
 
-	/* Reserve space for the record marker */
-	if (rqstp->rq_prot == IPPROTO_TCP)
-		svc_putnl(resv, 0);
-
 	/* Returns 1 for send, 0 for drop */
 	if (likely(svc_process_common(rqstp, argv, resv)))
 		return svc_send(rqstp);
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 47957088d7d3..4d2bdce48b64 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -175,111 +175,6 @@ static void svc_set_cmsg_data(struct svc_rqst *rqstp, struct cmsghdr *cmh)
 	}
 }
 
-/*
- * send routine intended to be shared by the fore- and back-channel
- */
-int svc_send_common(struct socket *sock, struct xdr_buf *xdr,
-		    struct page *headpage, unsigned long headoffset,
-		    struct page *tailpage, unsigned long tailoffset)
-{
-	int		result;
-	int		size;
-	struct page	**ppage = xdr->pages;
-	size_t		base = xdr->page_base;
-	unsigned int	pglen = xdr->page_len;
-	unsigned int	flags = MSG_MORE | MSG_SENDPAGE_NOTLAST;
-	int		slen;
-	int		len = 0;
-
-	slen = xdr->len;
-
-	/* send head */
-	if (slen == xdr->head[0].iov_len)
-		flags = 0;
-	len = kernel_sendpage(sock, headpage, headoffset,
-				  xdr->head[0].iov_len, flags);
-	if (len != xdr->head[0].iov_len)
-		goto out;
-	slen -= xdr->head[0].iov_len;
-	if (slen == 0)
-		goto out;
-
-	/* send page data */
-	size = PAGE_SIZE - base < pglen ? PAGE_SIZE - base : pglen;
-	while (pglen > 0) {
-		if (slen == size)
-			flags = 0;
-		result = kernel_sendpage(sock, *ppage, base, size, flags);
-		if (result > 0)
-			len += result;
-		if (result != size)
-			goto out;
-		slen -= size;
-		pglen -= size;
-		size = PAGE_SIZE < pglen ? PAGE_SIZE : pglen;
-		base = 0;
-		ppage++;
-	}
-
-	/* send tail */
-	if (xdr->tail[0].iov_len) {
-		result = kernel_sendpage(sock, tailpage, tailoffset,
-				   xdr->tail[0].iov_len, 0);
-		if (result > 0)
-			len += result;
-	}
-
-out:
-	return len;
-}
-
-
-/*
- * Generic sendto routine
- */
-static int svc_sendto(struct svc_rqst *rqstp, struct xdr_buf *xdr)
-{
-	struct svc_sock	*svsk =
-		container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
-	struct socket	*sock = svsk->sk_sock;
-	union {
-		struct cmsghdr	hdr;
-		long		all[SVC_PKTINFO_SPACE / sizeof(long)];
-	} buffer;
-	struct cmsghdr *cmh = &buffer.hdr;
-	int		len = 0;
-	unsigned long tailoff;
-	unsigned long headoff;
-	RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
-
-	if (rqstp->rq_prot == IPPROTO_UDP) {
-		struct msghdr msg = {
-			.msg_name	= &rqstp->rq_addr,
-			.msg_namelen	= rqstp->rq_addrlen,
-			.msg_control	= cmh,
-			.msg_controllen	= sizeof(buffer),
-			.msg_flags	= MSG_MORE,
-		};
-
-		svc_set_cmsg_data(rqstp, cmh);
-
-		if (sock_sendmsg(sock, &msg) < 0)
-			goto out;
-	}
-
-	tailoff = ((unsigned long)xdr->tail[0].iov_base) & (PAGE_SIZE-1);
-	headoff = 0;
-	len = svc_send_common(sock, xdr, rqstp->rq_respages[0], headoff,
-			       rqstp->rq_respages[0], tailoff);
-
-out:
-	dprintk("svc: socket %p sendto([%p %zu... ], %d) = %d (addr %s)\n",
-		svsk, xdr->head[0].iov_base, xdr->head[0].iov_len,
-		xdr->len, len, svc_print_addr(rqstp, buf, sizeof(buf)));
-
-	return len;
-}
-
 static void svc_sock_read_payload(struct svc_rqst *rqstp, unsigned int pos,
 				  unsigned long length)
 {
@@ -606,17 +501,45 @@ static int svc_udp_recvfrom(struct svc_rqst *rqstp)
 	return 0;
 }
 
-static int
-svc_udp_sendto(struct svc_rqst *rqstp)
+/**
+ * svc_udp_sendto - Send out a reply on a UDP socket
+ * @rqstp: completed svc_rqst
+ *
+ * Returns the number of bytes sent, or a negative errno.
+ */
+static int svc_udp_sendto(struct svc_rqst *rqstp)
 {
-	int		error;
+	struct svc_xprt *xprt = rqstp->rq_xprt;
+	struct svc_sock	*svsk = container_of(xprt, struct svc_sock, sk_xprt);
+	struct xdr_buf *xdr = &rqstp->rq_res;
+	union {
+		struct cmsghdr	hdr;
+		long		all[SVC_PKTINFO_SPACE / sizeof(long)];
+	} buffer;
+	struct cmsghdr *cmh = &buffer.hdr;
+	struct msghdr msg = {
+		.msg_name	= &rqstp->rq_addr,
+		.msg_namelen	= rqstp->rq_addrlen,
+		.msg_control	= cmh,
+		.msg_controllen	= sizeof(buffer),
+	};
+	unsigned int sent;
+	int err;
 
-	error = svc_sendto(rqstp, &rqstp->rq_res);
-	if (error == -ECONNREFUSED)
-		/* ICMP error on earlier request. */
-		error = svc_sendto(rqstp, &rqstp->rq_res);
+	svc_set_cmsg_data(rqstp, cmh);
 
-	return error;
+	sent = 0;
+	err = xprt_sock_sendmsg(svsk->sk_sock, &msg, xdr, 0, 0, &sent);
+	xdr_free_bvec(xdr);
+	if (err == -ECONNREFUSED) {
+		/* ICMP error on earlier request. */
+		sent = 0;
+		err = xprt_sock_sendmsg(svsk->sk_sock, &msg, xdr, 0, 0, &sent);
+		xdr_free_bvec(xdr);
+	}
+	if (err < 0)
+		return err;
+	return sent;
 }
 
 static int svc_udp_has_wspace(struct svc_xprt *xprt)
@@ -1135,35 +1058,40 @@ static int svc_tcp_recvfrom(struct svc_rqst *rqstp)
 	return 0;	/* record not complete */
 }
 
-/*
- * Send out data on TCP socket.
+/**
+ * svc_tcp_sendto - Send out a reply on a TCP socket
+ * @rqstp: completed svc_rqst
+ *
+ * Returns the number of bytes sent, or a negative errno.
  */
 static int svc_tcp_sendto(struct svc_rqst *rqstp)
 {
-	struct xdr_buf	*xbufp = &rqstp->rq_res;
-	int sent;
-	__be32 reclen;
+	struct svc_xprt *xprt = rqstp->rq_xprt;
+	struct svc_sock	*svsk = container_of(xprt, struct svc_sock, sk_xprt);
+	struct xdr_buf *xdr = &rqstp->rq_res;
+	rpc_fraghdr marker = rpc_stream_record_marker(xdr->len);
+	struct msghdr msg = {
+		.msg_flags	= 0,
+	};
+	unsigned int sent;
+	int err;
 
-	/* Set up the first element of the reply kvec.
-	 * Any other kvecs that may be in use have been taken
-	 * care of by the server implementation itself.
-	 */
-	reclen = htonl(0x80000000|((xbufp->len ) - 4));
-	memcpy(xbufp->head[0].iov_base, &reclen, 4);
-
-	sent = svc_sendto(rqstp, &rqstp->rq_res);
-	if (sent != xbufp->len) {
-		printk(KERN_NOTICE
-		       "rpc-srv/tcp: %s: %s %d when sending %d bytes "
-		       "- shutting down socket\n",
-		       rqstp->rq_xprt->xpt_server->sv_name,
-		       (sent<0)?"got error":"sent only",
-		       sent, xbufp->len);
-		set_bit(XPT_CLOSE, &rqstp->rq_xprt->xpt_flags);
-		svc_xprt_enqueue(rqstp->rq_xprt);
-		sent = -EAGAIN;
-	}
+	sent = 0;
+	err = xprt_sock_sendmsg(svsk->sk_sock, &msg, xdr, 0, marker, &sent);
+	xdr_free_bvec(xdr);
+	if (err < 0 || sent != (xdr->len + sizeof(marker)))
+		goto out_close;
 	return sent;
+
+out_close:
+	pr_notice("rpc-srv/tcp: %s: %s %d when sending %d bytes "
+		  "- shutting down socket\n",
+		  xprt->xpt_server->sv_name,
+		  (err < 0) ? "got error" : "sent",
+		  (err < 0) ? err : sent, xdr->len);
+	set_bit(XPT_CLOSE, &xprt->xpt_flags);
+	svc_xprt_enqueue(xprt);
+	return -EAGAIN;
 }
 
 static struct svc_xprt *svc_tcp_create(struct svc_serv *serv,
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 0380d72d8485..4fc38bd2f41e 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -2517,45 +2517,24 @@ static void bc_free(struct rpc_task *task)
 	free_page((unsigned long)buf);
 }
 
-/*
- * Use the svc_sock to send the callback. Must be called with svsk->sk_mutex
- * held. Borrows heavily from svc_tcp_sendto and xs_tcp_send_request.
- */
 static int bc_sendto(struct rpc_rqst *req)
 {
-	int len;
-	struct xdr_buf *xbufp = &req->rq_snd_buf;
+	struct xdr_buf *xdr = &req->rq_snd_buf;
 	struct sock_xprt *transport =
 			container_of(req->rq_xprt, struct sock_xprt, xprt);
-	unsigned long headoff;
-	unsigned long tailoff;
-	struct page *tailpage;
 	struct msghdr msg = {
-		.msg_flags	= MSG_MORE
-	};
-	rpc_fraghdr marker = rpc_stream_record_marker(xbufp->len);
-	struct kvec iov = {
-		.iov_base	= &marker,
-		.iov_len	= sizeof(marker),
+		.msg_flags	= 0,
 	};
+	rpc_fraghdr marker = rpc_stream_record_marker(xdr->len);
+	unsigned int sent = 0;
+	int err;
 
 	req->rq_xtime = ktime_get();
-
-	len = kernel_sendmsg(transport->sock, &msg, &iov, 1, iov.iov_len);
-	if (len != iov.iov_len)
+	err = xprt_sock_sendmsg(transport->sock, &msg, xdr, 0, marker, &sent);
+	xdr_free_bvec(xdr);
+	if (err < 0 || sent != (xdr->len + sizeof(marker)))
 		return -EAGAIN;
-
-	tailpage = NULL;
-	if (xbufp->tail[0].iov_len)
-		tailpage = virt_to_page(xbufp->tail[0].iov_base);
-	tailoff = (unsigned long)xbufp->tail[0].iov_base & ~PAGE_MASK;
-	headoff = (unsigned long)xbufp->head[0].iov_base & ~PAGE_MASK;
-	len = svc_send_common(transport->sock, xbufp,
-			      virt_to_page(xbufp->head[0].iov_base), headoff,
-			      tailpage, tailoff);
-	if (len != xbufp->len)
-		return -EAGAIN;
-	return len;
+	return sent;
 }
 
 /*