1 files changed, 59 insertions, 72 deletions

diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 8c9a8ee76aa0..998687421fa6 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -36,6 +36,8 @@
 #include <linux/skbuff.h>
 #include <linux/file.h>
 #include <linux/freezer.h>
+#include <linux/bvec.h>
+
 #include <net/sock.h>
 #include <net/checksum.h>
 #include <net/ip.h>
@@ -695,9 +697,10 @@ static int svc_udp_sendto(struct svc_rqst *rqstp)
 		.msg_name	= &rqstp->rq_addr,
 		.msg_namelen	= rqstp->rq_addrlen,
 		.msg_control	= cmh,
+		.msg_flags	= MSG_SPLICE_PAGES,
 		.msg_controllen	= sizeof(buffer),
 	};
-	unsigned int sent;
+	unsigned int count;
 	int err;
 
 	svc_udp_release_ctxt(xprt, rqstp->rq_xprt_ctxt);
@@ -710,22 +713,23 @@ static int svc_udp_sendto(struct svc_rqst *rqstp)
 	if (svc_xprt_is_dead(xprt))
 		goto out_notconn;
 
-	err = xdr_alloc_bvec(xdr, GFP_KERNEL);
-	if (err < 0)
-		goto out_unlock;
+	count = xdr_buf_to_bvec(rqstp->rq_bvec,
+				ARRAY_SIZE(rqstp->rq_bvec), xdr);
 
-	err = xprt_sock_sendmsg(svsk->sk_sock, &msg, xdr, 0, 0, &sent);
+	iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, rqstp->rq_bvec,
+		      count, 0);
+	err = sock_sendmsg(svsk->sk_sock, &msg);
 	if (err == -ECONNREFUSED) {
 		/* ICMP error on earlier request. */
-		err = xprt_sock_sendmsg(svsk->sk_sock, &msg, xdr, 0, 0, &sent);
+		iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, rqstp->rq_bvec,
+			      count, 0);
+		err = sock_sendmsg(svsk->sk_sock, &msg);
 	}
-	xdr_free_bvec(xdr);
+
 	trace_svcsock_udp_send(xprt, err);
-out_unlock:
+
 	mutex_unlock(&xprt->xpt_mutex);
-	if (err < 0)
-		return err;
-	return sent;
+	return err;
 
 out_notconn:
 	mutex_unlock(&xprt->xpt_mutex);
@@ -1089,6 +1093,9 @@ static void svc_tcp_fragment_received(struct svc_sock *svsk)
 	/* If we have more data, signal svc_xprt_enqueue() to try again */
 	svsk->sk_tcplen = 0;
 	svsk->sk_marker = xdr_zero;
+
+	smp_wmb();
+	tcp_set_rcvlowat(svsk->sk_sk, 1);
 }
 
 /**
@@ -1178,10 +1185,17 @@ err_incomplete:
 		goto err_delete;
 	if (len == want)
 		svc_tcp_fragment_received(svsk);
-	else
+	else {
+		/* Avoid more ->sk_data_ready() calls until the rest
+		 * of the message has arrived. This reduces service
+		 * thread wake-ups on large incoming messages. */
+		tcp_set_rcvlowat(svsk->sk_sk,
+				 svc_sock_reclen(svsk) - svsk->sk_tcplen);
+
 		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)
@@ -1198,75 +1212,51 @@ err_noclose:
 	return 0;	/* record not complete */
 }
 
-static int svc_tcp_send_kvec(struct socket *sock, const struct kvec *vec,
-			      int flags)
-{
-	struct msghdr msg = { .msg_flags = MSG_SPLICE_PAGES | flags, };
-
-	iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, vec, 1, vec->iov_len);
-	return sock_sendmsg(sock, &msg);
-}
-
 /*
  * MSG_SPLICE_PAGES is used exclusively to reduce the number of
  * copy operations in this path. Therefore the caller must ensure
  * that the pages backing @xdr are unchanging.
  *
- * In addition, the logic assumes that * .bv_len is never larger
- * than PAGE_SIZE.
+ * Note that the send is non-blocking. The caller has incremented
+ * the reference count on each page backing the RPC message, and
+ * the network layer will "put" these pages when transmission is
+ * complete.
+ *
+ * This is safe for our RPC services because the memory backing
+ * the head and tail components is never kmalloc'd. These always
+ * come from pages in the svc_rqst::rq_pages array.
  */
-static int svc_tcp_sendmsg(struct socket *sock, struct xdr_buf *xdr,
+static int svc_tcp_sendmsg(struct svc_sock *svsk, struct svc_rqst *rqstp,
 			   rpc_fraghdr marker, unsigned int *sentp)
 {
-	const struct kvec *head = xdr->head;
-	const struct kvec *tail = xdr->tail;
-	struct kvec rm = {
-		.iov_base	= &marker,
-		.iov_len	= sizeof(marker),
-	};
 	struct msghdr msg = {
-		.msg_flags	= 0,
+		.msg_flags	= MSG_SPLICE_PAGES,
 	};
+	unsigned int count;
+	void *buf;
 	int ret;
 
 	*sentp = 0;
-	ret = xdr_alloc_bvec(xdr, GFP_KERNEL);
-	if (ret < 0)
-		return ret;
-
-	ret = kernel_sendmsg(sock, &msg, &rm, 1, rm.iov_len);
-	if (ret < 0)
-		return ret;
-	*sentp += ret;
-	if (ret != rm.iov_len)
-		return -EAGAIN;
-
-	ret = svc_tcp_send_kvec(sock, head, 0);
-	if (ret < 0)
-		return ret;
-	*sentp += ret;
-	if (ret != head->iov_len)
-		goto out;
 
-	if (xdr_buf_pagecount(xdr))
-		xdr->bvec[0].bv_offset = offset_in_page(xdr->page_base);
-
-	msg.msg_flags = MSG_SPLICE_PAGES;
-	iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, xdr->bvec,
-		      xdr_buf_pagecount(xdr), xdr->page_len);
-	ret = sock_sendmsg(sock, &msg);
+	/* The stream record marker is copied into a temporary page
+	 * fragment buffer so that it can be included in rq_bvec.
+	 */
+	buf = page_frag_alloc(&svsk->sk_frag_cache, sizeof(marker),
+			      GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+	memcpy(buf, &marker, sizeof(marker));
+	bvec_set_virt(rqstp->rq_bvec, buf, sizeof(marker));
+
+	count = xdr_buf_to_bvec(rqstp->rq_bvec + 1,
+				ARRAY_SIZE(rqstp->rq_bvec) - 1, &rqstp->rq_res);
+
+	iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, rqstp->rq_bvec,
+		      1 + count, sizeof(marker) + rqstp->rq_res.len);
+	ret = sock_sendmsg(svsk->sk_sock, &msg);
 	if (ret < 0)
 		return ret;
 	*sentp += ret;
-
-	if (tail->iov_len) {
-		ret = svc_tcp_send_kvec(sock, tail, 0);
-		if (ret < 0)
-			return ret;
-		*sentp += ret;
-	}
-
-out:
 	return 0;
 }
 
@@ -1292,23 +1282,17 @@ static int svc_tcp_sendto(struct svc_rqst *rqstp)
 	svc_tcp_release_ctxt(xprt, rqstp->rq_xprt_ctxt);
 	rqstp->rq_xprt_ctxt = NULL;
 
-	atomic_inc(&svsk->sk_sendqlen);
 	mutex_lock(&xprt->xpt_mutex);
 	if (svc_xprt_is_dead(xprt))
 		goto out_notconn;
-	tcp_sock_set_cork(svsk->sk_sk, true);
-	err = svc_tcp_sendmsg(svsk->sk_sock, xdr, marker, &sent);
-	xdr_free_bvec(xdr);
+	err = svc_tcp_sendmsg(svsk, rqstp, marker, &sent);
 	trace_svcsock_tcp_send(xprt, err < 0 ? (long)err : sent);
 	if (err < 0 || sent != (xdr->len + sizeof(marker)))
 		goto out_close;
-	if (atomic_dec_and_test(&svsk->sk_sendqlen))
-		tcp_sock_set_cork(svsk->sk_sk, false);
 	mutex_unlock(&xprt->xpt_mutex);
 	return sent;
 
 out_notconn:
-	atomic_dec(&svsk->sk_sendqlen);
 	mutex_unlock(&xprt->xpt_mutex);
 	return -ENOTCONN;
 out_close:
@@ -1317,7 +1301,6 @@ out_close:
 		  (err < 0) ? "got error" : "sent",
 		  (err < 0) ? err : sent, xdr->len);
 	svc_xprt_deferred_close(xprt);
-	atomic_dec(&svsk->sk_sendqlen);
 	mutex_unlock(&xprt->xpt_mutex);
 	return -EAGAIN;
 }
@@ -1644,6 +1627,7 @@ static void svc_tcp_sock_detach(struct svc_xprt *xprt)
 static void svc_sock_free(struct svc_xprt *xprt)
 {
 	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
+	struct page_frag_cache *pfc = &svsk->sk_frag_cache;
 	struct socket *sock = svsk->sk_sock;
 
 	trace_svcsock_free(svsk, sock);
@@ -1653,5 +1637,8 @@ static void svc_sock_free(struct svc_xprt *xprt)
 		sockfd_put(sock);
 	else
 		sock_release(sock);
+	if (pfc->va)
+		__page_frag_cache_drain(virt_to_head_page(pfc->va),
+					pfc->pagecnt_bias);
 	kfree(svsk);
 }