From 2a6c555082b47e0d78645b598c57c721a857d3af Mon Sep 17 00:00:00 2001
From: Jacek Galowicz <galowicz@lfbs.rwth-aachen.de>
Date: Thu, 14 Apr 2011 17:21:17 +0200
Subject: [PATCH] File read/write offset

Added offset integration.
---
 kernel/syscall.c | 26 +++++++++++++++++++-------
 1 file changed, 19 insertions(+), 7 deletions(-)

diff --git a/kernel/syscall.c b/kernel/syscall.c
index d55ee699..74b7d653 100644
--- a/kernel/syscall.c
+++ b/kernel/syscall.c
@@ -26,17 +26,29 @@
 
 static int sys_read(int fd, const char *buf, size_t len)
 {
-	read_fs(per_core(current_task)->fildes_table[fd].node, (uint8_t*)buf, len, per_core(current_task)->fildes_table[fd].offset);
-	kprintf("fd:%i, Dateilaenge:%i, Dateiinhalt: %s \n", fd, len, buf);
-	return len; ////////ACHTUNG: liest noch über das Dateiende hinaus
+	unsigned int readbytes;
+	readbytes = read_fs(
+			per_core(current_task)->fildes_table[fd].node, 
+			(uint8_t*)buf, len, 
+			per_core(current_task)->fildes_table[fd].offset);
+	per_core(current_task)->fildes_table[fd].offset += readbytes;
+	/*kprintf("fd:%i, Dateilaenge:%i, Dateiinhalt: %s \n", fd, len, buf);*/
+	/* Beware: still reading above file limit! */
+	return readbytes; 
 }
 
 static int sys_write(int fd, const char *buf, size_t len)
 {
-	//per_core(current_task)->fildes_table[fd].node->write = 1;
-	write_fs(per_core(current_task)->fildes_table[fd].node, (uint8_t*)buf, len, 0);//per_core(current_task)->fildes_table[fd].offset);
-	kprintf("ins Dateis. geschr. -- fd:%i, Dateilaenge:%i, Dateiinhalt: %s \n", fd, len, buf);
-	return len; ////////ACHTUNG: gaukelt dem Benutzer vor alles geschrieben zu haben.
+	unsigned int wrotebytes;
+	/* per_core(current_task)->fildes_table[fd].node->write = 1; */
+	wrotebytes = write_fs(
+			per_core(current_task)->fildes_table[fd].node, 
+			(uint8_t*)buf, len, 0);
+	/* per_core(current_task)->fildes_table[fd].offset); */
+	/* kprintf("ins Dateis. geschr. -- fd:%i, Dateilaenge:%i, Dateiinhalt: %s \n", fd, len, buf); */
+	per_core(current_task)->fildes_table[fd].offset += wrotebytes;
+
+	return wrotebytes;
 }
 
 static int sys_open(const char* file, int flags, int mode)