From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CBB93C468A0 for ; Fri, 5 Jul 2019 17:39:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9D5EE216E3 for ; Fri, 5 Jul 2019 17:39:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="PIZNiJ1W" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728059AbfGERjJ (ORCPT ); Fri, 5 Jul 2019 13:39:09 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:53722 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728000AbfGERjJ (ORCPT ); Fri, 5 Jul 2019 13:39:09 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=/uC5M3ierRS+Hhs1DpFJF+UTUe2DRAKcMjsTpsN7uZU=; b=PIZNiJ1WxKKIRw+vM1xmzPDsL sos6egHIMaJUiMNPTIuMXWSQ37rv6LOoI+JVLpTJ8X73yb8qeUREX3Ec7OesnOKF0USoCH3iC+LR0 2w1ENFIGOYQDbVL3vMwOjBlrXLTWp3oKFhTmcv1+O4eQcFIx0zQuGXvJwu05JnBPuZDtvg0MqVG5O FfsrPh6pURk8BqtN/JPBvgNNr3g7r/02ag/RkW/R++nWwo2NJF17XXyJPr472WQ/1o5NySoaF15BR aT9dpouC9xEof94S20lQs3Qa7jeXW5CqJizZIuoo/jU/Rpqa/Qi6EkxlM0HsnldJ6M/RTdSZ2LQH3 0Cmlqc4OA==; Received: from willy by bombadil.infradead.org with local (Exim 4.92 #3 (Red Hat Linux)) id 1hjSAs-0006Q6-3F; Fri, 05 Jul 2019 17:39:06 +0000 Date: Fri, 5 Jul 2019 10:39:06 -0700 From: Matthew Wilcox To: James Bottomley Cc: Theodore Ts'o , linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, Parisc List Subject: Re: Question about ext4 testing: need to produce a high depth extent tree to verify mapping code Message-ID: <20190705173905.GA32320@bombadil.infradead.org> References: <1562021070.2762.36.camel@HansenPartnership.com> <20190702002355.GB3315@mit.edu> <1562028814.2762.50.camel@HansenPartnership.com> <20190702173301.GA3032@mit.edu> <1562095894.3321.52.camel@HansenPartnership.com> <20190702203937.GG3032@mit.edu> <1562343948.2953.8.camel@HansenPartnership.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1562343948.2953.8.camel@HansenPartnership.com> User-Agent: Mutt/1.11.4 (2019-03-13) Sender: linux-parisc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org On Fri, Jul 05, 2019 at 09:25:48AM -0700, James Bottomley wrote: > Now the problem: I'd like to do some testing with high depth extent > trees to make sure I got this right, but the files we load at boot are > ~20MB in size and I'm having a hard time fragmenting the filesystem > enough to produce a reasonable extent (I've basically only got to a two > level tree with two entries at the top). Is there an easy way of > producing a high depth extent tree for a 20MB file? Create a series of 4kB files numbered sequentially, each 4kB in size until you fill the partition. Delete the even numbered ones. Create a 20MB file.