Merge tag 'nfsd-5.11-1' of git://git.linux-nfs.org/projects/cel/cel-2.6

Pull nfsd fixes from Chuck Lever:

 - Fix major TCP performance regression

 - Get NFSv4.2 READ_PLUS regression tests to pass

 - Improve NFSv4 COMPOUND memory allocation

 - Fix sparse warning

* tag 'nfsd-5.11-1' of git://git.linux-nfs.org/projects/cel/cel-2.6:
  NFSD: Restore NFSv4 decoding's SAVEMEM functionality
  SUNRPC: Handle TCP socket sends with kernel_sendpage() again
  NFSD: Fix sparse warning in nfssvc.c
  nfsd: Don't set eof on a truncated READ_PLUS
  nfsd: Fixes for nfsd4_encode_read_plus_data()

5 files changed, 126 insertions, 28 deletions

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 4727b7f03c5b..8d6d2678abad 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -50,6 +50,11 @@
 #include "pnfs.h"
 #include "trace.h"
 
+static bool inter_copy_offload_enable;
+module_param(inter_copy_offload_enable, bool, 0644);
+MODULE_PARM_DESC(inter_copy_offload_enable,
+		 "Enable inter server to server copy offload. Default: false");
+
 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
 #include <linux/security.h>
 
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 45ee6b12ce5b..eaaa1605b5b5 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -147,6 +147,25 @@ svcxdr_dupstr(struct nfsd4_compoundargs *argp, void *buf, u32 len)
 	return p;
 }
 
+static void *
+svcxdr_savemem(struct nfsd4_compoundargs *argp, __be32 *p, u32 len)
+{
+	__be32 *tmp;
+
+	/*
+	 * The location of the decoded data item is stable,
+	 * so @p is OK to use. This is the common case.
+	 */
+	if (p != argp->xdr->scratch.iov_base)
+		return p;
+
+	tmp = svcxdr_tmpalloc(argp, len);
+	if (!tmp)
+		return NULL;
+	memcpy(tmp, p, len);
+	return tmp;
+}
+
 /*
  * NFSv4 basic data type decoders
  */
@@ -183,11 +202,10 @@ nfsd4_decode_opaque(struct nfsd4_compoundargs *argp, struct xdr_netobj *o)
 	p = xdr_inline_decode(argp->xdr, len);
 	if (!p)
 		return nfserr_bad_xdr;
-	o->data = svcxdr_tmpalloc(argp, len);
+	o->data = svcxdr_savemem(argp, p, len);
 	if (!o->data)
 		return nfserr_jukebox;
 	o->len = len;
-	memcpy(o->data, p, len);
 
 	return nfs_ok;
 }
@@ -205,10 +223,9 @@ nfsd4_decode_component4(struct nfsd4_compoundargs *argp, char **namp, u32 *lenp)
 	status = check_filename((char *)p, *lenp);
 	if (status)
 		return status;
-	*namp = svcxdr_tmpalloc(argp, *lenp);
+	*namp = svcxdr_savemem(argp, p, *lenp);
 	if (!*namp)
 		return nfserr_jukebox;
-	memcpy(*namp, p, *lenp);
 
 	return nfs_ok;
 }
@@ -1200,10 +1217,9 @@ nfsd4_decode_putfh(struct nfsd4_compoundargs *argp, struct nfsd4_putfh *putfh)
 	p = xdr_inline_decode(argp->xdr, putfh->pf_fhlen);
 	if (!p)
 		return nfserr_bad_xdr;
-	putfh->pf_fhval = svcxdr_tmpalloc(argp, putfh->pf_fhlen);
+	putfh->pf_fhval = svcxdr_savemem(argp, p, putfh->pf_fhlen);
 	if (!putfh->pf_fhval)
 		return nfserr_jukebox;
-	memcpy(putfh->pf_fhval, p, putfh->pf_fhlen);
 
 	return nfs_ok;
 }
@@ -1318,24 +1334,20 @@ nfsd4_decode_setclientid(struct nfsd4_compoundargs *argp, struct nfsd4_setclient
 	p = xdr_inline_decode(argp->xdr, setclientid->se_callback_netid_len);
 	if (!p)
 		return nfserr_bad_xdr;
-	setclientid->se_callback_netid_val = svcxdr_tmpalloc(argp,
+	setclientid->se_callback_netid_val = svcxdr_savemem(argp, p,
 						setclientid->se_callback_netid_len);
 	if (!setclientid->se_callback_netid_val)
 		return nfserr_jukebox;
-	memcpy(setclientid->se_callback_netid_val, p,
-	       setclientid->se_callback_netid_len);
 
 	if (xdr_stream_decode_u32(argp->xdr, &setclientid->se_callback_addr_len) < 0)
 		return nfserr_bad_xdr;
 	p = xdr_inline_decode(argp->xdr, setclientid->se_callback_addr_len);
 	if (!p)
 		return nfserr_bad_xdr;
-	setclientid->se_callback_addr_val = svcxdr_tmpalloc(argp,
+	setclientid->se_callback_addr_val = svcxdr_savemem(argp, p,
 						setclientid->se_callback_addr_len);
 	if (!setclientid->se_callback_addr_val)
 		return nfserr_jukebox;
-	memcpy(setclientid->se_callback_addr_val, p,
-	       setclientid->se_callback_addr_len);
 	if (xdr_stream_decode_u32(argp->xdr, &setclientid->se_callback_ident) < 0)
 		return nfserr_bad_xdr;
 
@@ -1375,10 +1387,9 @@ nfsd4_decode_verify(struct nfsd4_compoundargs *argp, struct nfsd4_verify *verify
 	p = xdr_inline_decode(argp->xdr, verify->ve_attrlen);
 	if (!p)
 		return nfserr_bad_xdr;
-	verify->ve_attrval = svcxdr_tmpalloc(argp, verify->ve_attrlen);
+	verify->ve_attrval = svcxdr_savemem(argp, p, verify->ve_attrlen);
 	if (!verify->ve_attrval)
 		return nfserr_jukebox;
-	memcpy(verify->ve_attrval, p, verify->ve_attrlen);
 
 	return nfs_ok;
 }
@@ -2333,10 +2344,9 @@ nfsd4_decode_compound(struct nfsd4_compoundargs *argp)
 		p = xdr_inline_decode(argp->xdr, argp->taglen);
 		if (!p)
 			return 0;
-		argp->tag = svcxdr_tmpalloc(argp, argp->taglen);
+		argp->tag = svcxdr_savemem(argp, p, argp->taglen);
 		if (!argp->tag)
 			return 0;
-		memcpy(argp->tag, p, argp->taglen);
 		max_reply += xdr_align_size(argp->taglen);
 	}
 
@@ -4756,6 +4766,7 @@ nfsd4_encode_read_plus_data(struct nfsd4_compoundres *resp,
 			    resp->rqstp->rq_vec, read->rd_vlen, maxcount, eof);
 	if (nfserr)
 		return nfserr;
+	xdr_truncate_encode(xdr, starting_len + 16 + xdr_align_size(*maxcount));
 
 	tmp = htonl(NFS4_CONTENT_DATA);
 	write_bytes_to_xdr_buf(xdr->buf, starting_len,      &tmp,   4);
@@ -4763,6 +4774,10 @@ nfsd4_encode_read_plus_data(struct nfsd4_compoundres *resp,
 	write_bytes_to_xdr_buf(xdr->buf, starting_len + 4,  &tmp64, 8);
 	tmp = htonl(*maxcount);
 	write_bytes_to_xdr_buf(xdr->buf, starting_len + 12, &tmp,   4);
+
+	tmp = xdr_zero;
+	write_bytes_to_xdr_buf(xdr->buf, starting_len + 16 + *maxcount, &tmp,
+			       xdr_pad_size(*maxcount));
 	return nfs_ok;
 }
 
@@ -4855,14 +4870,15 @@ out:
 	if (nfserr && segments == 0)
 		xdr_truncate_encode(xdr, starting_len);
 	else {
-		tmp = htonl(eof);
-		write_bytes_to_xdr_buf(xdr->buf, starting_len,     &tmp, 4);
-		tmp = htonl(segments);
-		write_bytes_to_xdr_buf(xdr->buf, starting_len + 4, &tmp, 4);
 		if (nfserr) {
 			xdr_truncate_encode(xdr, last_segment);
 			nfserr = nfs_ok;
+			eof = 0;
 		}
+		tmp = htonl(eof);
+		write_bytes_to_xdr_buf(xdr->buf, starting_len,     &tmp, 4);
+		tmp = htonl(segments);
+		write_bytes_to_xdr_buf(xdr->buf, starting_len + 4, &tmp, 4);
 	}
 
 	return nfserr;
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 00384c332f9b..f9c9f4c63cc7 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -33,12 +33,6 @@
 
 #define NFSDDBG_FACILITY	NFSDDBG_SVC
 
-bool inter_copy_offload_enable;
-EXPORT_SYMBOL_GPL(inter_copy_offload_enable);
-module_param(inter_copy_offload_enable, bool, 0644);
-MODULE_PARM_DESC(inter_copy_offload_enable,
-		 "Enable inter server to server copy offload. Default: false");
-
 extern struct svc_program	nfsd_program;
 static int			nfsd(void *vrqstp);
 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
index a60ff5ce1a37..c300885ae75d 100644
--- a/fs/nfsd/xdr4.h
+++ b/fs/nfsd/xdr4.h
@@ -568,7 +568,6 @@ struct nfsd4_copy {
 	struct nfs_fh		c_fh;
 	nfs4_stateid		stateid;
 };
-extern bool inter_copy_offload_enable;
 
 struct nfsd4_seek {
 	/* request */
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index b248f2349437..c9766d07eb81 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -1062,6 +1062,90 @@ err_noclose:
 	return 0;	/* record not complete */
 }
 
+static int svc_tcp_send_kvec(struct socket *sock, const struct kvec *vec,
+			      int flags)
+{
+	return kernel_sendpage(sock, virt_to_page(vec->iov_base),
+			       offset_in_page(vec->iov_base),
+			       vec->iov_len, flags);
+}
+
+/*
+ * kernel_sendpage() 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.
+ */
+static int svc_tcp_sendmsg(struct socket *sock, struct msghdr *msg,
+			   struct xdr_buf *xdr, 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),
+	};
+	int flags, ret;
+
+	*sentp = 0;
+	xdr_alloc_bvec(xdr, GFP_KERNEL);
+
+	msg->msg_flags = MSG_MORE;
+	ret = kernel_sendmsg(sock, msg, &rm, 1, rm.iov_len);
+	if (ret < 0)
+		return ret;
+	*sentp += ret;
+	if (ret != rm.iov_len)
+		return -EAGAIN;
+
+	flags = head->iov_len < xdr->len ? MSG_MORE | MSG_SENDPAGE_NOTLAST : 0;
+	ret = svc_tcp_send_kvec(sock, head, flags);
+	if (ret < 0)
+		return ret;
+	*sentp += ret;
+	if (ret != head->iov_len)
+		goto out;
+
+	if (xdr->page_len) {
+		unsigned int offset, len, remaining;
+		struct bio_vec *bvec;
+
+		bvec = xdr->bvec;
+		offset = xdr->page_base;
+		remaining = xdr->page_len;
+		flags = MSG_MORE | MSG_SENDPAGE_NOTLAST;
+		while (remaining > 0) {
+			if (remaining <= PAGE_SIZE && tail->iov_len == 0)
+				flags = 0;
+			len = min(remaining, bvec->bv_len);
+			ret = kernel_sendpage(sock, bvec->bv_page,
+					      bvec->bv_offset + offset,
+					      len, flags);
+			if (ret < 0)
+				return ret;
+			*sentp += ret;
+			if (ret != len)
+				goto out;
+			remaining -= len;
+			offset = 0;
+			bvec++;
+		}
+	}
+
+	if (tail->iov_len) {
+		ret = svc_tcp_send_kvec(sock, tail, 0);
+		if (ret < 0)
+			return ret;
+		*sentp += ret;
+	}
+
+out:
+	return 0;
+}
+
 /**
  * svc_tcp_sendto - Send out a reply on a TCP socket
  * @rqstp: completed svc_rqst
@@ -1089,7 +1173,7 @@ static int svc_tcp_sendto(struct svc_rqst *rqstp)
 	mutex_lock(&xprt->xpt_mutex);
 	if (svc_xprt_is_dead(xprt))
 		goto out_notconn;
-	err = xprt_sock_sendmsg(svsk->sk_sock, &msg, xdr, 0, marker, &sent);
+	err = svc_tcp_sendmsg(svsk->sk_sock, &msg, xdr, marker, &sent);
 	xdr_free_bvec(xdr);
 	trace_svcsock_tcp_send(xprt, err < 0 ? err : sent);
 	if (err < 0 || sent != (xdr->len + sizeof(marker)))