From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from plane.gmane.org ([80.91.229.3]:43599 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751044AbbALFX3 (ORCPT ); Mon, 12 Jan 2015 00:23:29 -0500 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1YAXTK-0003uP-Nh for linux-btrfs@vger.kernel.org; Mon, 12 Jan 2015 06:23:26 +0100 Received: from ip68-231-22-224.ph.ph.cox.net ([68.231.22.224]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 12 Jan 2015 06:23:26 +0100 Received: from 1i5t5.duncan by ip68-231-22-224.ph.ph.cox.net with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 12 Jan 2015 06:23:26 +0100 To: linux-btrfs@vger.kernel.org From: Duncan <1i5t5.duncan@cox.net> Subject: Re: What about storing more crc32 in the unused csum size for metadata? Date: Mon, 12 Jan 2015 05:23:16 +0000 (UTC) Message-ID: References: <54B3323E.3090100@cn.fujitsu.com> <54B353EE.6090605@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: Qu Wenruo posted on Mon, 12 Jan 2015 12:56:14 +0800 as excerpted: > Oh, my fault, sector 1 should contains csum for the second eighth of the > leaf/node... > Since the first eighth csum can be calculated vice verse. > > Thanks, Thanks indeed. /Now/ it makes sense. Skip the one and reverse-calculate it. (Which you had actually implied and I guess it doesn't matter which one as long as it's /only/ one, but given my general unfamiliarity with crc at a practical level and impaired logic state, and your hiding it in the ... gap, I needed a bit more help to make the leap. =:^) -- Duncan - List replies preferred. No HTML msgs. "Every nonfree program has a lord, a master -- and if you use the program, he is your master." Richard Stallman