diff -Nru mm/filemap.c.orig mm/filemap.c
--- mm/filemap.c.orig	Wed Apr 30 17:19:56 2003
+++ mm/filemap.c	Fri May 30 14:01:12 2003
@@ -1574,6 +1574,42 @@
 	UPDATE_ATIME(inode);
 }
 
+#include <asm/debug.h>
+static int wrong_flag;
+void check_value(struct kiobuf * iobuf, size_t iosize, loff_t offset, size_t count, size_t retval)
+{
+	int i,val;
+	db_assert(iosize == count);
+	db_assert(retval == count);
+
+	/*
+	printk("iobuf->nr_pages=%d, offset=%lld, iosize=%d, pages=%d(%d)\n",
+			iobuf->nr_pages,
+			offset,
+			iosize,
+			iosize/1024/4,
+			iosize % (1024*4));
+	return;
+	*/
+
+	val = offset / 4;
+	for (i=0; i< iobuf->nr_pages; i++) {
+		int *p=page_address(iobuf->maplist[i]);
+		int j;
+		for(j=0; j<1024; j++,p++,val++) {
+			if (val != *p) 
+				if (!wrong_flag) {
+					wrong_flag=1;
+				printk("wrong at %d: got %d, expect %d\n",
+						(int)(offset + i*1024*4 + j*4),
+						*p,
+						val);
+				}
+		}
+	}
+}
+
+#include <linux/jstrace.h>
 static ssize_t generic_file_direct_IO(int rw, struct file * filp, char * buf, size_t count, loff_t offset)
 {
 	ssize_t retval;
@@ -1583,6 +1619,7 @@
 	struct inode * inode = mapping->host;
 	loff_t size = inode->i_size;
 
+
 	new_iobuf = 0;
 	iobuf = filp->f_iobuf;
 	if (test_and_set_bit(0, &filp->f_iobuf_lock)) {
@@ -1601,6 +1638,14 @@
 	blocksize_mask = blocksize - 1;
 	chunk_size = KIO_MAX_ATOMIC_IO << 10;
 
+	/*
+	printk("JSUN: generic_file_direct_IO - count = %d, offset = %d\n",
+			count, offset);
+	*/
+	/*
+	printk("JSUN : chunk_size = %d (%x)\n", chunk_size, chunk_size);
+	*/
+
 	retval = -EINVAL;
 	if ((offset & blocksize_mask) || (count & blocksize_mask))
 		goto out_free;
@@ -1634,6 +1679,8 @@
 
 		retval = mapping->a_ops->direct_IO(rw, inode, iobuf, (offset+progress) >> blocksize_bits, blocksize);
 
+		check_value(iobuf, iosize, offset, count, retval);
+
 		if (rw == READ && retval > 0)
 			mark_dirty_kiobuf(iobuf, retval);