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=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 BBE1AC43603 for ; Wed, 18 Dec 2019 04:06:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 977AF206EE for ; Wed, 18 Dec 2019 04:06:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726496AbfLREGx (ORCPT ); Tue, 17 Dec 2019 23:06:53 -0500 Received: from zeniv.linux.org.uk ([195.92.253.2]:55532 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726387AbfLREGx (ORCPT ); Tue, 17 Dec 2019 23:06:53 -0500 Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1ihQbr-0002cz-KC; Wed, 18 Dec 2019 04:06:51 +0000 Date: Wed, 18 Dec 2019 04:06:51 +0000 From: Al Viro To: Eric Sandeen Cc: fsdevel , David Howells Subject: Re: [PATCH V2] fs_parser: remove fs_parameter_description name field Message-ID: <20191218040651.GH4203@ZenIV.linux.org.uk> References: <22be7526-d9da-5309-22a8-3405ed1c0842@sandeen.net> <20191218033606.GF4203@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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 09:43:44PM -0600, Eric Sandeen wrote: > On 12/17/19 9:36 PM, Al Viro wrote: > > On Fri, Dec 06, 2019 at 10:31:57AM -0600, Eric Sandeen wrote: > >> There doesn't seem to be a strong reason to have a copy of the > >> filesystem name string in the fs_parameter_description structure; > >> it's easy enough to get the name from the fs_type, and using it > >> instead ensures consistency across messages (for example, > >> vfs_parse_fs_param() already uses fc->fs_type->name for the error > >> messages, because it doesn't have the fs_parameter_description). > > > > Arrgh... That used to be fine. Now we have this: > > static int rbd_parse_param(struct fs_parameter *param, > > struct rbd_parse_opts_ctx *pctx) > > { > > struct rbd_options *opt = pctx->opts; > > struct fs_parse_result result; > > int token, ret; > > > > ret = ceph_parse_param(param, pctx->copts, NULL); > > if (ret != -ENOPARAM) > > return ret; > > > > token = fs_parse(NULL, rbd_parameters, param, &result); > > ^^^^ > > > > Cthulhu damn it... And yes, that crap used to work. > > Frankly, I'm tempted to allocate fs_context in there (in > > rbd_parse_options(), or in rbd_add_parse_args()) - we've other > > oddities due to that... > > > > Alternatively, we could provide __fs_parse() that > > would take name as a separate argument and accepted NULL fc, > > with fs_parse() being a wrapper for that. > > > > *grumble* > > FYI be careful if you do munge this in, V2 inexplicably killed the name in > the fs_type for afs. V3 fixed that thinko or whatever it was. I used v3, anyway... The reason I'm rather unhappy about the entire situation is that in the end of that series I have fs_param_is_u32() et.al. being _functions_. With switch in fs_parse() gone. Typical instance looks like this: int fs_param_is_enum(struct fs_context *fc, const struct fs_parameter_spec *p, struct fs_parameter *param, struct fs_parse_result *result) { const struct constant_table *c; if (param->type != fs_value_is_string) return fs_param_bad_value(fc, param); c = __lookup_constant(p->data, param->string); if (!c) return fs_param_bad_value(fc, param); result->uint_32 = c->value; return 0; } and I would rather not breed the arguments here ;-/ I could take logging into the fs_parse() itself (it's very similar in all current instances), but... if we go for something like int fs_param_is_range(struct fs_context *fc, const struct fs_parameter_spec *p, struct fs_parameter *param, struct fs_parse_result *result) { const struct {u32 from, to;} *range = p->data; if (param->type != fs_value_is_string || kstrtouint(param->string, 0, &result->uint_32) < 0) return fs_param_bad_value(fc, param); if (result->uint_32 < range->from || result->uint_32 > range->to) return invalf(fc, "%s: Value for %s must be in [%u..%u]", fc->fs_type->name, param->key, range->from, range->to); return 0; } which is not all that unreasonable, the requirement of handling all warnings in fs_parse() becomes unfeasible. And the main reason for conversion to method is the pressure to provide such custom types - stuff like {|K|M|G} for memory sizes, etc. Shite... We can, of course, pass the name to instances, but... *ugh*