Cleanup XDR parsing for LAYOUTGET, GETDEVICEINFO

changes LAYOUTGET and GETDEVICEINFO XDR parsing to:
 - not use vmap, which doesn't work on incoherent archs
 - use xdr_stream parsing for all xdr

Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 207d399..40da65e 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -2656,6 +2656,10 @@
 	encode_sequence(xdr, &args->seq_args, &hdr);
 	encode_putfh(xdr, NFS_FH(args->inode), &hdr);
 	encode_layoutget(xdr, args, &hdr);
+
+	xdr_inline_pages(&req->rq_rcv_buf, hdr.replen << 2,
+	    args->layout.pages, 0, args->layout.pglen);
+
 	encode_nops(&hdr);
 }
 
@@ -5022,6 +5026,9 @@
 	__be32 *p;
 	int status;
 	u32 layout_count;
+	struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
+	struct kvec *iov = rcvbuf->head;
+	u32 hdrlen, recvd;
 
 	status = decode_op_hdr(xdr, OP_LAYOUTGET);
 	if (status)
@@ -5038,17 +5045,14 @@
 		return -EINVAL;
 	}
 
-	p = xdr_inline_decode(xdr, 24);
+	p = xdr_inline_decode(xdr, 28);
 	if (unlikely(!p))
 		goto out_overflow;
 	p = xdr_decode_hyper(p, &res->range.offset);
 	p = xdr_decode_hyper(p, &res->range.length);
 	res->range.iomode = be32_to_cpup(p++);
 	res->type = be32_to_cpup(p++);
-
-	status = decode_opaque_inline(xdr, &res->layout.len, (char **)&p);
-	if (unlikely(status))
-		return status;
+	res->layoutp->len = be32_to_cpup(p);
 
 	dprintk("%s roff:%lu rlen:%lu riomode:%d, lo_type:0x%x, lo.len:%d\n",
 		__func__,
@@ -5056,12 +5060,18 @@
 		(unsigned long)res->range.length,
 		res->range.iomode,
 		res->type,
-		res->layout.len);
+		res->layoutp->len);
 
-	/* nfs4_proc_layoutget allocated a single page */
-	if (res->layout.len > PAGE_SIZE)
-		return -ENOMEM;
-	memcpy(res->layout.buf, p, res->layout.len);
+	hdrlen = (u8 *) xdr->p - (u8 *) iov->iov_base;
+	recvd = req->rq_rcv_buf.len - hdrlen;
+	if (res->layoutp->len > recvd) {
+		dprintk("NFS: server cheating in layoutget reply: "
+				"layout len %u > recvd %u\n",
+				res->layoutp->len, recvd);
+		return -EINVAL;
+	}
+
+	xdr_read_pages(xdr, res->layoutp->len);
 
 	if (layout_count > 1) {
 		/* We only handle a length one array at the moment.  Any