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_2 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 8A84BC468A7 for ; Fri, 5 Jul 2019 18:49:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 67D6620989 for ; Fri, 5 Jul 2019 18:49:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="W6E4PtOy"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="wzs/V+kl" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726805AbfGEStF (ORCPT ); Fri, 5 Jul 2019 14:49:05 -0400 Received: from bedivere.hansenpartnership.com ([66.63.167.143]:58608 "EHLO bedivere.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725865AbfGEStE (ORCPT ); Fri, 5 Jul 2019 14:49:04 -0400 Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 370348EE1F7; Fri, 5 Jul 2019 11:49:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=hansenpartnership.com; s=20151216; t=1562352544; bh=pRKHY8qZ/7aIRatoNEiEEL+ERx8f+mdPdRR1Tdm7ndw=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=W6E4PtOyGc789JxSB/eoi9v4cD20Yg0krCULsLgDG/aU3PXOmSzpDmZ8ebxZXrfsK QJ/DN0shjYfv3Cx9gZQ19T2yDvPCgu6iGOfEpPp72liXqFL/TuLyhKHf8oq5UGD8Pr BVz8jdF48GEO7bqVTHfEqKETAwZjy9OCGWW1+Lo4= Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id yJ5aKR7xYlEs; Fri, 5 Jul 2019 11:49:04 -0700 (PDT) Received: from jarvis.lan (unknown [50.35.68.20]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by bedivere.hansenpartnership.com (Postfix) with ESMTPSA id A5FD48EE0CF; Fri, 5 Jul 2019 11:49:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=hansenpartnership.com; s=20151216; t=1562352543; bh=pRKHY8qZ/7aIRatoNEiEEL+ERx8f+mdPdRR1Tdm7ndw=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=wzs/V+kl3Zh2xJYA0ChAOFiJ+ATqWXbNodPwz5Htmz7e1kfPakjgXBPuUq15aSCzA ur5OK488sRWWl4iCokcNfAbkdg7gmg7eE2UJU+clTQihZk9l5WA659g5vwXbxvTCqe PQQwwJfVTh1+gDM0eEEsba8S70cf8xFMGcqJqXsc= Message-ID: <1562352542.2953.10.camel@HansenPartnership.com> Subject: Re: Question about ext4 testing: need to produce a high depth extent tree to verify mapping code From: James Bottomley To: Matthew Wilcox Cc: Theodore Ts'o , linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, Parisc List Date: Fri, 05 Jul 2019 11:49:02 -0700 In-Reply-To: <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> <20190705173905.GA32320@bombadil.infradead.org> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.26.6 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Fri, 2019-07-05 at 10:39 -0700, Matthew Wilcox wrote: > 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. Well, I know *how* to do it ... I was just hoping, in the interests of creative laziness, that someone else had produced a script for this before I had to ... particularly one which leaves more randomized gaps. James