diff -urNp nfs-ref/include/asm-i386/highmem.h nfs/include/asm-i386/highmem.h
--- nfs-ref/include/asm-i386/highmem.h	2003-02-14 07:01:58.000000000 +0100
+++ nfs/include/asm-i386/highmem.h	2003-02-20 21:42:17.000000000 +0100
@@ -56,16 +56,19 @@ extern void kmap_init(void) __init;
 #define PKMAP_NR(virt)  ((virt-PKMAP_BASE) >> PAGE_SHIFT)
 #define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
 
-extern void * FASTCALL(kmap_high(struct page *page));
+extern void * FASTCALL(kmap_high(struct page *page, int nonblocking));
 extern void FASTCALL(kunmap_high(struct page *page));
 
-static inline void *kmap(struct page *page)
+#define kmap(page) __kmap(page, 0)
+#define kmap_nonblock(page) __kmap(page, 1)
+
+static inline void *__kmap(struct page *page, int nonblocking)
 {
 	if (in_interrupt())
 		out_of_line_bug();
 	if (page < highmem_start_page)
 		return page_address(page);
-	return kmap_high(page);
+	return kmap_high(page, nonblocking);
 }
 
 static inline void kunmap(struct page *page)
diff -urNp nfs-ref/include/linux/sunrpc/xdr.h nfs/include/linux/sunrpc/xdr.h
--- nfs-ref/include/linux/sunrpc/xdr.h	2003-02-19 01:12:41.000000000 +0100
+++ nfs/include/linux/sunrpc/xdr.h	2003-02-20 21:39:51.000000000 +0100
@@ -137,7 +137,7 @@ void xdr_zero_iovec(struct iovec *, int,
  * XDR buffer helper functions
  */
 extern int xdr_kmap(struct iovec *, struct xdr_buf *, unsigned int);
-extern void xdr_kunmap(struct xdr_buf *, unsigned int);
+extern void xdr_kunmap(struct xdr_buf *, unsigned int, int);
 extern void xdr_shift_buf(struct xdr_buf *, size_t);
 
 /*
diff -urNp nfs-ref/mm/highmem.c nfs/mm/highmem.c
--- nfs-ref/mm/highmem.c	2002-11-29 02:23:18.000000000 +0100
+++ nfs/mm/highmem.c	2003-02-20 21:45:27.000000000 +0100
@@ -77,7 +77,7 @@ static void flush_all_zero_pkmaps(void)
 	flush_tlb_all();
 }
 
-static inline unsigned long map_new_virtual(struct page *page)
+static inline unsigned long map_new_virtual(struct page *page, int nonblocking)
 {
 	unsigned long vaddr;
 	int count;
@@ -96,6 +96,9 @@ start:
 		if (--count)
 			continue;
 
+		if (nonblocking)
+			return 0;
+
 		/*
 		 * Sleep for somebody else to unmap their entries
 		 */
@@ -126,7 +129,7 @@ start:
 	return vaddr;
 }
 
-void *kmap_high(struct page *page)
+void *kmap_high(struct page *page, int nonblocking)
 {
 	unsigned long vaddr;
 
@@ -138,11 +141,15 @@ void *kmap_high(struct page *page)
 	 */
 	spin_lock(&kmap_lock);
 	vaddr = (unsigned long) page->virtual;
-	if (!vaddr)
-		vaddr = map_new_virtual(page);
+	if (!vaddr) {
+		vaddr = map_new_virtual(page, nonblocking);
+		if (!vaddr)
+			goto out;
+	}
 	pkmap_count[PKMAP_NR(vaddr)]++;
 	if (pkmap_count[PKMAP_NR(vaddr)] < 2)
 		BUG();
+ out:
 	spin_unlock(&kmap_lock);
 	return (void*) vaddr;
 }
diff -urNp nfs-ref/net/sunrpc/xdr.c nfs/net/sunrpc/xdr.c
--- nfs-ref/net/sunrpc/xdr.c	2002-11-29 02:23:23.000000000 +0100
+++ nfs/net/sunrpc/xdr.c	2003-02-20 21:39:51.000000000 +0100
@@ -180,7 +180,7 @@ int xdr_kmap(struct iovec *iov_base, str
 {
 	struct iovec	*iov = iov_base;
 	struct page	**ppage = xdr->pages;
-	unsigned int	len, pglen = xdr->page_len;
+	unsigned int	len, pglen = xdr->page_len, first_kmap;
 
 	len = xdr->head[0].iov_len;
 	if (base < len) {
@@ -203,9 +203,17 @@ int xdr_kmap(struct iovec *iov_base, str
 		ppage += base >> PAGE_CACHE_SHIFT;
 		base &= ~PAGE_CACHE_MASK;
 	}
+	first_kmap = 1;
 	do {
 		len = PAGE_CACHE_SIZE;
-		iov->iov_base = kmap(*ppage);
+		if (first_kmap) {
+			first_kmap = 0;
+			iov->iov_base = kmap(*ppage);
+		} else {
+			iov->iov_base = kmap_nonblock(*ppage);
+			if (!iov->iov_base)
+				goto out;
+		}
 		if (base) {
 			iov->iov_base += base;
 			len -= base;
@@ -223,20 +231,23 @@ map_tail:
 		iov->iov_base = (char *)xdr->tail[0].iov_base + base;
 		iov++;
 	}
+ out:
 	return (iov - iov_base);
 }
 
-void xdr_kunmap(struct xdr_buf *xdr, unsigned int base)
+void xdr_kunmap(struct xdr_buf *xdr, unsigned int base, int niov)
 {
 	struct page	**ppage = xdr->pages;
 	unsigned int	pglen = xdr->page_len;
 
 	if (!pglen)
 		return;
-	if (base > xdr->head[0].iov_len)
+	if (base >= xdr->head[0].iov_len)
 		base -= xdr->head[0].iov_len;
-	else
+	else {
+		niov--;
 		base = 0;
+	}
 
 	if (base >= pglen)
 		return;
@@ -250,7 +261,11 @@ void xdr_kunmap(struct xdr_buf *xdr, uns
 		 * we bump pglen here, and just subtract PAGE_CACHE_SIZE... */
 		pglen += base & ~PAGE_CACHE_MASK;
 	}
-	for (;;) {
+	/*
+	 * In case we could only do a partial xdr_kmap, all remaining iovecs
+	 * refer to pages. Otherwise we detect the end through pglen.
+	 */
+	for (; niov; niov--) {
 		flush_dcache_page(*ppage);
 		kunmap(*ppage);
 		if (pglen <= PAGE_CACHE_SIZE)
@@ -322,9 +337,22 @@ void
 xdr_shift_buf(struct xdr_buf *xdr, size_t len)
 {
 	struct iovec iov[MAX_IOVEC];
-	unsigned int nr;
+	unsigned int nr, len_part, n, skip;
+
+	skip = 0;
+	do {
+
+		nr = xdr_kmap(iov, xdr, skip);
+
+		len_part = 0;
+		for (n = 0; n < nr; n++)
+			len_part += iov[n].iov_len;
+
+		xdr_shift_iovec(iov, nr, len_part);
+
+		xdr_kunmap(xdr, skip, nr);
 
-	nr = xdr_kmap(iov, xdr, 0);
-	xdr_shift_iovec(iov, nr, len);
-	xdr_kunmap(xdr, 0);
+		skip += len_part;
+		len -= len_part;
+	} while (len);
 }
diff -urNp nfs-ref/net/sunrpc/xprt.c nfs/net/sunrpc/xprt.c
--- nfs-ref/net/sunrpc/xprt.c	2003-01-29 06:14:32.000000000 +0100
+++ nfs/net/sunrpc/xprt.c	2003-02-20 21:39:51.000000000 +0100
@@ -226,23 +226,34 @@ xprt_sendmsg(struct rpc_xprt *xprt, stru
 	/* Dont repeat bytes */
 	skip = req->rq_bytes_sent;
 	slen = xdr->len - skip;
-	niov = xdr_kmap(niv, xdr, skip);
+	oldfs = get_fs(); set_fs(get_ds());
+	do {
+		unsigned int slen_part, n;
 
-	msg.msg_flags   = MSG_DONTWAIT|MSG_NOSIGNAL;
-	msg.msg_iov	= niv;
-	msg.msg_iovlen	= niov;
-	msg.msg_name	= (struct sockaddr *) &xprt->addr;
-	msg.msg_namelen = sizeof(xprt->addr);
-	msg.msg_control = NULL;
-	msg.msg_controllen = 0;
+		niov = xdr_kmap(niv, xdr, skip);
 
-	oldfs = get_fs(); set_fs(get_ds());
-	clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
-	result = sock_sendmsg(sock, &msg, slen);
+		msg.msg_flags   = MSG_DONTWAIT|MSG_NOSIGNAL;
+		msg.msg_iov	= niv;
+		msg.msg_iovlen	= niov;
+		msg.msg_name	= (struct sockaddr *) &xprt->addr;
+		msg.msg_namelen = sizeof(xprt->addr);
+		msg.msg_control = NULL;
+		msg.msg_controllen = 0;
+
+		slen_part = 0;
+		for (n = 0; n < niov; n++)
+			slen_part += niv[n].iov_len;
+
+		clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
+		result = sock_sendmsg(sock, &msg, slen_part);
+
+		xdr_kunmap(xdr, skip, niov);
+
+		skip += slen_part;
+		slen -= slen_part;
+	} while (result >= 0 && slen);
 	set_fs(oldfs);
 
-	xdr_kunmap(xdr, skip);
-
 	dprintk("RPC:      xprt_sendmsg(%d) = %d\n", slen, result);
 
 	if (result >= 0)