UML - Tidy recently-moved code

Index: linux-2.6.21-mm/arch/um/drivers/chan_user.c
===================================================================
@@ -23,43 +23,43 @@
 
 void generic_close(int fd, void *unused)
 {
-	os_close_file(fd);
+	close(fd);
 }
 
 int generic_read(int fd, char *c_out, void *unused)
 {
 	int n;
 
-	n = os_read_file(fd, c_out, sizeof(*c_out));
-
-	if(n == -EAGAIN)
+	n = read(fd, c_out, sizeof(*c_out));
+	if (n > 0)
+		return n;
+	else if (errno == EAGAIN)
 		return 0;
-	else if(n == 0)
+	else if (n == 0)
 		return -EIO;
-	return n;
+	return -errno;
 }
 
-/* XXX Trivial wrapper around os_write_file */
+/* XXX Trivial wrapper around write */
 
 int generic_write(int fd, const char *buf, int n, void *unused)
 {
-	return os_write_file(fd, buf, n);
+	return write(fd, buf, n);
 }
 
 int generic_window_size(int fd, void *unused, unsigned short *rows_out,
 			unsigned short *cols_out)
 {
-	int rows, cols;
+	struct winsize size;
 	int ret;
 
-	ret = os_window_size(fd, &rows, &cols);
-	if(ret < 0)
-		return ret;
+	if(ioctl(fd, TIOCGWINSZ, &size) < 0)
+		return -errno;
 
-	ret = ((*rows_out != rows) || (*cols_out != cols));
+	ret = ((*rows_out != size.ws_row) || (*cols_out != size.ws_col));
 
-	*rows_out = rows;
-	*cols_out = cols;
+	*rows_out = size.ws_row;
+	*cols_out = size.ws_col;
 
 	return ret;
 }

Index: linux-2.6.21-mm/arch/um/include/os.h
===================================================================
@@ -134,7 +134,6 @@ extern void os_print_error(int error, co
 extern int os_get_exec_close(int fd, int *close_on_exec);
 extern int os_set_exec_close(int fd, int close_on_exec);
 extern int os_ioctl_generic(int fd, unsigned int cmd, unsigned long arg);
-extern int os_window_size(int fd, int *rows, int *cols);
 extern int os_new_tty_pgrp(int fd, int pid);
 extern int os_get_ifname(int fd, char *namebuf);
 extern int os_set_slip(int fd);

Index: linux-2.6.21-mm/arch/um/os-Linux/file.c
===================================================================
@@ -101,19 +101,6 @@ int os_ioctl_generic(int fd, unsigned in
 	return err;
 }
 
-int os_window_size(int fd, int *rows, int *cols)
-{
-	struct winsize size;
-
-	if(ioctl(fd, TIOCGWINSZ, &size) < 0)
-		return -errno;
-
-	*rows = size.ws_row;
-	*cols = size.ws_col;
-
-	return 0;
-}
-
 int os_new_tty_pgrp(int fd, int pid)
 {
 	if(ioctl(fd, TIOCSCTTY, 0) < 0)