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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 21A9CC433E1 for ; Fri, 19 Jun 2020 16:50:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E8E2D206B7 for ; Fri, 19 Jun 2020 16:50:19 +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="ZitOErWS" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2393434AbgFSQuR (ORCPT ); Fri, 19 Jun 2020 12:50:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52304 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387909AbgFSOir (ORCPT ); Fri, 19 Jun 2020 10:38:47 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5E365C06174E for ; Fri, 19 Jun 2020 07:38:47 -0700 (PDT) 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; bh=2OEfwnCrJIPg1QpQKfmHfkzg+qZjNDZh72BKoIM9y3s=; b=ZitOErWS+utxrFXH4UPSynGJaj hNJyUCPH+0PktltFLGPSjeKqkHqNfdwwqVOuydKBBOWezRt293TINgr2JuSXpOZ52cM7u357IOSrc WdVBewaCsMJ5X2ixcJKXbC++aghngnx4ZfWBCup6pRzj+uwHZxg5GczThoPowh4YWKRxhy74EIFad Jf/bvRwxIkPiApaFEoSWLpu9/2+ZvYyHtYvBrXB1+2KIjVqjf6a+R985DUVlWJHY6HjJjHUvcuFlh vW11gL8KcKGchhFVaAZV+LZmKrg94CZBRQ6NbXO7RTlNVhPcOAGyXSuwZwZjWdpg1hC+0lJ7ny1Jg VP53uvdQ==; Received: from hch by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jmIAI-0002sK-Ck; Fri, 19 Jun 2020 14:38:46 +0000 Date: Fri, 19 Jun 2020 07:38:46 -0700 From: Christoph Hellwig To: Chandan Babu R Cc: linux-xfs@vger.kernel.org, david@fromorbit.com, darrick.wong@oracle.com, bfoster@redhat.com, hch@infradead.org Subject: Re: [PATCH 6/7] xfs: Extend data extent counter to 47 bits Message-ID: <20200619143846.GC29528@infradead.org> References: <20200606082745.15174-1-chandanrlinux@gmail.com> <20200606082745.15174-7-chandanrlinux@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200606082745.15174-7-chandanrlinux@gmail.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Sat, Jun 06, 2020 at 01:57:44PM +0530, Chandan Babu R wrote: > This commit extends the per-inode data extent counter to 47 bits. The > length of 47-bits was chosen because, > Maximum file size = 2^63. > Maximum extent count when using 64k block size = 2^63 / 2^16 = 2^47. What is the use case for a large nuber of extents? I'm not sure why we'd want to bother, but if there is a good reason it really should be documented here.