From: Felipe Monteiro de Carvalho Subject: Re: Which features should I implement in my ext4 reader? Date: Thu, 5 Sep 2013 09:04:19 +0200 Message-ID: References: <20130819050803.GA10882@gmail.com> <20130820103956.GA7846@gmail.com> <20130902120718.GB1106@gmail.com> <20130904053503.GA3518@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: "Theodore Ts'o" , linux-ext4@vger.kernel.org To: jon ernst Return-path: Received: from mail-pa0-f50.google.com ([209.85.220.50]:33703 "EHLO mail-pa0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757632Ab3IEHEU (ORCPT ); Thu, 5 Sep 2013 03:04:20 -0400 Received: by mail-pa0-f50.google.com with SMTP id fb10so1524672pad.9 for ; Thu, 05 Sep 2013 00:04:19 -0700 (PDT) In-Reply-To: Sender: linux-ext4-owner@vger.kernel.org List-ID: Hello, On Thu, Sep 5, 2013 at 6:50 AM, jon ernst wrote: > But I don't quite understand why does Felipe suspect those padding 0s? > What's wrong with it? Pardon my silly question. My point is why there are exactly 3 zeroes of padding? Can sometimes it be 2 zeroes? Or 1? Or none? How is this decided? Any tips to where in the source code this padding is decided? I am implementing my own ext4 reader library so I am not using the standard library, so this kind of detail is very important to me to make sure that my implementation is correct. For now I hard coded the existence of 3 zeroes of padding, but maybe the amount could be different? Is it to make sure that the block of data starts aligned to 4-bytes? thanks, -- Felipe Monteiro de Carvalho