From: Theodore Ts'o Subject: Re: [PATCH 3/3] mke2fs: prevent creation of unmountable ext4 with large flex_bg count Date: Sat, 5 Jul 2014 22:43:58 -0400 Message-ID: <20140706024358.GG19036@thunk.org> References: <28989C0C9F1C0A428470D967B5FCED372A7EA3@BPXM22GP.gisp.nec.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Ext4 Developers List To: Akira Fujita Return-path: Received: from imap.thunk.org ([74.207.234.97]:47188 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751494AbaGFCn7 (ORCPT ); Sat, 5 Jul 2014 22:43:59 -0400 Content-Disposition: inline In-Reply-To: <28989C0C9F1C0A428470D967B5FCED372A7EA3@BPXM22GP.gisp.nec.co.jp> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Wed, Jun 11, 2014 at 08:38:10AM +0000, Akira Fujita wrote: > In mke2fs command, if flex_bg count is too large to filesystem blocks count, > unmountable ext4 which has the out of filesystem block offset is created (Case1). > Moreover this large flex_bg count causes an unintentional metadata layout > (bmap-imap-itable-bmap-imap-itable .. in block group) (Case2). > > To fix these issues and keep healthy flex_bg layout, disallow creating ext4 > with obviously large flex_bg count to filesystem blocks count. Applied, thanks. - Ted