From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from imap.thunk.org ([74.207.234.97]:53028 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726145AbeKZNuT (ORCPT ); Mon, 26 Nov 2018 08:50:19 -0500 Date: Sun, 25 Nov 2018 21:57:35 -0500 From: "Theodore Y. Ts'o" To: "Darrick J. Wong" Cc: linux-ext4 , Elana.Hashman@twosigma.com Subject: Re: [PATCH] e2freefrag: fix free blocks count during live scan Message-ID: <20181126025735.GB7904@thunk.org> References: <20181108184431.GA27852@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181108184431.GA27852@magnolia> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Thu, Nov 08, 2018 at 10:44:31AM -0800, Darrick J. Wong wrote: > From: Darrick J. Wong > > In e2freefrag live scan mode, we take the free block count from the > ondisk superblock. This leads to screwy histogram percentages: > > Extent Size Range : Free extents Free Blocks Percent > 4M... 8M- : 5 8234 1.05% > 64M... 128M- : 2 52279 6.64% > 512M... 1024M- : 1 202752 25.74% > > ...because there could be superblock updates in the journal that haven't > yet been checkpointed. The online scan is perfectly capable of tallying > the free blocks on its own, so teach it do that and make a more accurate > report. > > Reported-by: Elana Hashman > Signed-off-by: Darrick J. Wong Thanks, applied. - Ted