From: Theodore Ts'o Subject: Re: [PATCH v2] ext4: Fix growing of tiny filesystems Date: Sun, 3 May 2015 00:00:38 -0400 Message-ID: <20150503040038.GH10014@thunk.org> References: <1430377561-6079-1-git-send-email-jack@suse.cz> <55423DAA.6020305@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Jan Kara , linux-ext4@vger.kernel.org, =?utf-8?B?THVrw6HFoQ==?= Czerner To: Eric Sandeen Return-path: Received: from imap.thunk.org ([74.207.234.97]:41755 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750772AbbECEAn (ORCPT ); Sun, 3 May 2015 00:00:43 -0400 Content-Disposition: inline In-Reply-To: <55423DAA.6020305@redhat.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Thu, Apr 30, 2015 at 09:35:22AM -0500, Eric Sandeen wrote: > On 4/30/15 2:06 AM, Jan Kara wrote: > > The estimate of necessary transaction credits in ext4_flex_group_add() > > is too pessimistic. It reserves credit for sb, resize inode, and resize > > inode dindirect block for each group added in a flex group although they > > are always the same block and thus it is enough to account them only > > once. Also the number of modified GDT block is overestimated since we > > fit EXT4_DESC_PER_BLOCK(sb) descriptors in one block. > > > > Make the estimation more precise. That reduces number of requested > > credits enough that we can grow 20 MB filesystem (which has 1 MB > > journal, 79 reserved GDT blocks, and flex group size 16 by default). > > > > Signed-off-by: Jan Kara > > Jan, thank you for looking into this and sorting it out. > > Reviewed-by: Eric Sandeen Applied, thanks. - Ted