From patchwork Mon Jul 2 11:07:26 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Disseldorp X-Patchwork-Id: 10501151 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 0931D6035E for ; Mon, 2 Jul 2018 11:25:32 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EA6A7286F5 for ; Mon, 2 Jul 2018 11:25:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DEB0228718; Mon, 2 Jul 2018 11:25:31 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI, T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0834D286F5 for ; Mon, 2 Jul 2018 11:25:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965402AbeGBLZ2 (ORCPT ); Mon, 2 Jul 2018 07:25:28 -0400 Received: from hr2.samba.org ([144.76.82.148]:41950 "EHLO hr2.samba.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965131AbeGBLZ2 (ORCPT ); Mon, 2 Jul 2018 07:25:28 -0400 X-Greylist: delayed 1078 seconds by postgrey-1.27 at vger.kernel.org; Mon, 02 Jul 2018 07:25:27 EDT DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=samba.org; s=42627210; h=Message-ID:Cc:To:From:Date; bh=4+r+mISiLSKyQ78E9l7GdqZ3boRzA/KZKClRKR17wBk=; b=HbIvpql5lFlV7qYspxrJHxM1/l ybNGOD2+VwPcX7bXV8tVpzK5mBaIWC2PYLlGpRhOwm1kX5tDtZQY+uGDPg9yM+XUzsEI+MUiegY9H Q2twz2YkW9/jhsl66BOoxPAFIDsLAgxjM/8+XWtip6WiClomf9u0HtM3qXW46+9VmrD4=; Received: from [127.0.0.2] (localhost [127.0.0.1]) by hr2.samba.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim) id 1fZwg4-0001rW-CG; Mon, 02 Jul 2018 11:07:28 +0000 Date: Mon, 2 Jul 2018 13:07:26 +0200 From: David Disseldorp To: Nikolay Borisov Cc: Su Yue , linux-btrfs@vger.kernel.org Subject: Re: [PATCH RFC 0/3] btrfs-progs: lowmem: delay before lowmem repair Message-ID: <20180702130726.21a3257d@samba.org> In-Reply-To: <93c08062-8368-616f-f8c6-5ff8616aad08@suse.com> References: <20180702092820.16285-1-suy.fnst@cn.fujitsu.com> <93c08062-8368-616f-f8c6-5ff8616aad08@suse.com> X-Mailer: Claws Mail 3.13.2 (GTK+ 2.24.31; x86_64-suse-linux-gnu) MIME-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On Mon, 2 Jul 2018 12:43:20 +0300, Nikolay Borisov wrote: > On 2.07.2018 12:28, Su Yue wrote: > > Since lowmem repair is dangerous, it should remind user more obviously. > > The patchset add 10 seconds delay like btrfs balance and add am option > > '--force-repair-lowmem' to skip the delay. > > IMO this is the wrong way to approach a dangerous option. If it's so > dangerous it needs to be written in the documentation explicitly this is > so. If someone wants to use lowmem then they should explicitly set > --mode lowmem. So I'm inclined to NACK this patch. AFAICT it's already documented as "experimental" in the manpage, but the usage flag appears to have been dropped as part of refactoring for 87c1bd13c1fca430c3dbf0da62e9aa33bde609c8 . If nobody's working on a fix, and lowmem removal isn't an option, then please consider adding the usage flag back, e.g. Cheers, David --- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html --- a/check/main.c +++ b/check/main.c @@ -9386,7 +9386,7 @@ const char * const cmd_check_usage[] = { " original - read inodes and extents to memory (requires", " more memory, does less IO)", " lowmem - try to use less memory but read blocks again", - " when needed", + " when needed (experimental)", "--check-data-csum verify checksums of data blocks", "-Q|--qgroup-report print a report on qgroup consistency", "-E|--subvol-extents ",