random: drop weird m_time/a_time manipulation

commit a996996 upstream. No other driver does anything remotely like this that I know of except for the tty drivers, and I can't see any reason for random/urandom to do it. In fact, it's a (trivial, harmless) timing information leak. And obviously, it generates power- and flash-cycle wasting I/O, especially if combined with something like hwrngd. Also, it breaks ubifs's expectations. Signed-off-by: Matt Mackall <[email protected]> Signed-off-by: Herbert Xu <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
CyanogenMod · Feb 9, 2010 · 8857a1a · 8857a1a
1 parent 94af44b
commit 8857a1a
Showing 1 changed file with 0 additions and 8 deletions.
diff --git a/drivers/char/random.c b/drivers/char/random.c
@@ -1051,12 +1051,6 @@ random_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos)
 				/* like a named pipe */
 	}
 
-	/*
-	 * If we gave the user some bytes, update the access time.
-	 */
-	if (count)
-		file_accessed(file);
-
 	return (count ? count : retval);
 }
 
@@ -1116,8 +1110,6 @@ static ssize_t random_write(struct file *file, const char __user *buffer,
 	if (ret)
 		return ret;
 
-	inode->i_mtime = current_fs_time(inode->i_sb);
-	mark_inode_dirty(inode);
 	return (ssize_t)count;
 }