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=-2.2 required=3.0 tests=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 37ACAC43603 for ; Tue, 17 Dec 2019 03:27:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 10A402072B for ; Tue, 17 Dec 2019 03:27:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727323AbfLQD1r (ORCPT ); Mon, 16 Dec 2019 22:27:47 -0500 Received: from zeniv.linux.org.uk ([195.92.253.2]:37100 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726698AbfLQD1r (ORCPT ); Mon, 16 Dec 2019 22:27:47 -0500 Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1ih3WT-0006Me-9Z; Tue, 17 Dec 2019 03:27:45 +0000 Date: Tue, 17 Dec 2019 03:27:45 +0000 From: Al Viro To: Miklos Szeredi Cc: linux-fsdevel@vger.kernel.org, Andrew Price , David Howells , stable@vger.kernel.org Subject: Re: [PATCH 02/12] fs_parse: fix fs_param_v_optional handling Message-ID: <20191217032745.GR4203@ZenIV.linux.org.uk> References: <20191128155940.17530-1-mszeredi@redhat.com> <20191128155940.17530-3-mszeredi@redhat.com> <20191216232845.GP4203@ZenIV.linux.org.uk> <20191217011813.GQ4203@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191217011813.GQ4203@ZenIV.linux.org.uk> User-Agent: Mutt/1.12.1 (2019-06-15) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Tue, Dec 17, 2019 at 01:18:13AM +0000, Al Viro wrote: > So how about a flag for "takes no arguments", set automatically by > fsparam_flag()/fsparam_flag_no(), with fs_lookup_key() taking an > extra "comes with argument" flag and filtering according to it? > Rules: > foo => "foo", true > foo= => "foo", false > foo=bar => "foo", false > And to hell with the "optional" flag; for gfs2 we'd end up with > fsparam_flag_no("quota", Opt_quota_flag), // quota|noquota > fsparam_flag_enum("quota", Opt_quota, gfs2_param_quota), // quota={on|account|off} > Postprocessing won't be any harder, really - we could bloody well do > case Opt_quota_flag: > result.int_32 = result.negated ? GFS2_QUOTA_OFF : GFS2_QUOTA_ON; > /* fallthru */ > case Opt_quota: > args->ar_quota = result.int_32; > break; > with gfs2_param_quota having the right values in it, instead of > that intermediate enum. > > All ->has_value checks go away that way, AFAICS. With minimal > impact on yet-to-be-merged series... FWIW, we have the following types right now: fs_param_is_flag no argument fs_param_is_bool no argument or string argument (1 instance in mainline[*]) fs_param_is_u32 string argument [**] fs_param_is_u32_octal string argument fs_param_is_u32_hex string argument fs_param_is_s32 string argument fs_param_is_u64 string argument fs_param_is_enum string argument; gfs2 has the quota/noquota/quota=... mess fs_param_is_string string argument; ceph (and nfs) have fsc/nofsc/fsc=... fs_param_is_fd unused at the moment; eventually - string argument. fs_param_is_blob fsconfig-only fs_param_is_blockdev fsconfig-only fs_param_is_path fsconfig-only [*] no_disconnect in gadgetfs; buggered, since it used to require a numeric argument. Now it quietly treats no_disconnect as no_disconnect=1 and rejects e.g. no_disconnect=2. There are two more in ext4, also buggered as far as I can tell. [**] ext4 has init_itable/init_itable=%u/noinit_itable The total over all filesystems with conversions posted or already in mainline: * no_disconnect [drivers/usb/gadget/function/f_fs.c, broken] * init_itable/init_itable=%u/noinit_itable [ext4] * fsc/fsc=%s/nofsc [ceph] * fsc/fsc=%s/nofsc [nfs] * quota/quota=on/quota=off/quota=account/noquota [gfs2] * barrier/barrier=%u/nobarrier [ext4] * auto_da_alloc/auto_da_alloc=%u/noauto_da_alloc [ext4] It's rare. So much that I don't believe that fs_param_v_optional has any reason to exist. Let's split those entries and be done with that. Hmm... Deciding whether we have an argument-bearing or no-argument case is somewhat inconvenient for fsconfig-generated calls - check for NULL param->string is, strictly speaking, in nasal daemon territory for types other than flag and string... OK, sold - let's check for fs_value_is_flag. So I'm combining your patch with #9/12 (to avoid bisect hazard) + correction for rbd. And putting that in the very beginning of fs_parser reorg series, with elimination of fs_param_v_optional closer to the end.