From: Felipe Monteiro de Carvalho Subject: Beginner questions about ext4 Date: Wed, 12 Jun 2013 12:20:26 +0000 (UTC) Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit To: linux-ext4@vger.kernel.org Return-path: Received: from plane.gmane.org ([80.91.229.3]:37379 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750878Ab3FLMUp (ORCPT ); Wed, 12 Jun 2013 08:20:45 -0400 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1Umk2d-0001Ob-FP for linux-ext4@vger.kernel.org; Wed, 12 Jun 2013 14:20:43 +0200 Received: from 91.241.2.251 ([91.241.2.251]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 12 Jun 2013 14:20:43 +0200 Received: from felipemonteiro.carvalho by 91.241.2.251 with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 12 Jun 2013 14:20:43 +0200 Sender: linux-ext4-owner@vger.kernel.org List-ID: Hello, I am starting with ext4 development, so I have lot's of questions =) 1> About ext4 feature FLEX_BG, I see that it merges multiple groups in 1 group, but I wonder how this makes sense... In ext3 did each block group contain always 1 block? If not, then how many? And if not, how does that differ from FLEX_BG? 2> I see that the number of groups inside a flexible group is given by 2^sb.s_log_groups_per_flex but: a> Every single group is a flexible group or some are and some now? b> This number is the same for all flexible groups? 3> Could anyone be kind enough to post the full path which is done to find data in a given file? I already found inode.i_block .... wonder what are the other links between things, like for example between a group and inodes, etc... thanks, Felipe Monteiro de Carvalho PS: I need to restrict each line to 80 chars because of gmane, sorry for that =(