From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754706AbcKIXlS (ORCPT ); Wed, 9 Nov 2016 18:41:18 -0500 Received: from mail.kernel.org ([198.145.29.136]:48360 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752287AbcKIXlO (ORCPT ); Wed, 9 Nov 2016 18:41:14 -0500 MIME-Version: 1.0 In-Reply-To: <20161108224726.GD13978@wotan.suse.de> References: <20160824203901.GT3296@wotan.suse.de> <20160825194133.GC3296@wotan.suse.de> <20160902235916.GO3296@wotan.suse.de> <20160903002014.GP3296@wotan.suse.de> <6332a54e-74c6-eafd-368e-71e87a3fa34e@landley.net> <20161005180017.GD3296@wotan.suse.de> <20161005194633.GE3296@wotan.suse.de> <20161108224726.GD13978@wotan.suse.de> From: "Luis R. Rodriguez" Date: Wed, 9 Nov 2016 15:40:45 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [RFC] fs: add userspace critical mounts event support To: Linus Torvalds , Jiri Kosina , Johannes Berg , Jouni Malinen , Seth Forshee , Tom Gundersen , Kay Sievers , Bjorn Andersson , Daniel Wagner , Daniel Wagner , "Rafael J. Wysocki" , Harald Hoyer Cc: "Luis R. Rodriguez" , "Herbert, Marc" , Daniel Vetter , Rob Landley , Mimi Zohar , Felix Fietkau , David Woodhouse , Roman Pen , Ming Lei , Andrew Morton , Michal Marek , Greg KH , Linux Kernel Mailing List , Vikram Mulukutla , Stephen Boyd , Mark Brown , Takashi Iwai , Christian Lamparter , Hauke Mehrtens , Josh Boyer , Dmitry Torokhov , Jiri Slaby , Andy Lutomirski , Wu Fengguang , Richard Purdie , Jeff Mahoney , Jacek Anaszewski , Abhay Salunke , Julia Lawall , Gilles Muller , Nicolas Palix , David Howells , Alessandro Rubini , Kevin Cernekee , Kees Cook , Jonathan Corbet , Thierry Martinez , linux-serial , "open list:DOCUMENTATION" , linuxppc-dev , Josh Triplett Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 8, 2016 at 2:47 PM, Luis R. Rodriguez wrote: > Whatever the outcome of this discussion is -- Johannes seemed to *want* > to further use the UMH by default on *all* async alls... even if the > driver did not explicitly requested it -- I'm concerned about this given > all the above and the existing flip/flop on systemd for it. Whatever > we try to dream up here, please consider all the above as well. One addition to this: the current API does not always require the UMH firmware fallback, for most distributions that do not enable CONFIG_FW_LOADER_USER_HELPER_FALLBACK but do enable CONFIG_FW_LOADER_USER_HELPER we only require the UMH firmware fallback *iff* the driver explicitly requests it. For kernels with CONFIG_FW_LOADER_USER_HELPER_FALLBACK enabled we *always* use the UMH fallback. By fallback note that this means its used only if the first direct filesystem request failed. For further details on complexities of the UMH refer to two ongoing threads [0] [1] about it. Johannes, you seemed to note you added some uevent classifier for async requests, I checked and it seems this was with commit e9045f9178f3e ("firmware class: export nowait to userspace") was this the change you were referring to ? Even with all these complexities annotated, do you still believe we need the UMH always for all async calls ? [0] https://lkml.kernel.org/r/20161109211741.GI13978@wotan.suse.de [1] https://lkml.kernel.org/r/20161109220210.GJ13978@wotan.suse.de Luis