[PATCH] cpuset crapectomy

Switched cpuset_common_file_read() to simple_read_from_buffer(), killed
a bunch of useless (and not quite correct - e.g.  min(size_t,ssize_t))
code.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

kernel/cpuset.c

@@ -968,8 +968,6 @@ static ssize_t cpuset_common_file_read(struct file *file, char __user *buf,
 	char *page;
 	ssize_t retval = 0;
 	char *s;
-	char *start;
-	ssize_t n;
 
 	if (!(page = (char *)__get_free_page(GFP_KERNEL)))
 		return -ENOMEM;
@@ -999,15 +997,7 @@ static ssize_t cpuset_common_file_read(struct file *file, char __user *buf,
 	*s++ = '\n';
 	*s = '\0';
 
-	start = page + *ppos;
-	n = s - start;
-
-	/* Do nothing if *ppos is at the eof or beyond the eof. */
-	if (n <= 0)
-		goto out;
-
-	retval = n - copy_to_user(buf, start, min(n, nbytes));
-	*ppos += retval;
+	retval = simple_read_from_buffer(buf, nbytes, ppos, page, s - page);
 out:
 	free_page((unsigned long)page);
 	return retval;