ocfs2: update file system paths to set atime

Conditionally update atime in ocfs2_file_aio_read(), ocfs2_readdir() and
ocfs2_mmap().

Signed-off-by: Tiger Yang <tiger.yang@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
diff --git a/fs/ocfs2/symlink.c b/fs/ocfs2/symlink.c
index c0f68aa..957d687 100644
--- a/fs/ocfs2/symlink.c
+++ b/fs/ocfs2/symlink.c
@@ -126,6 +126,10 @@
 		goto out;
 	}
 
+	/*
+	 * Without vfsmount we can't update atime now,
+	 * but we will update atime here ultimately.
+	 */
 	ret = vfs_readlink(dentry, buffer, buflen, link);
 
 	brelse(bh);