Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932299AbcDSOiq (ORCPT ); Tue, 19 Apr 2016 10:38:46 -0400 Received: from mail-wm0-f44.google.com ([74.125.82.44]:36293 "EHLO mail-wm0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932282AbcDSOin convert rfc822-to-8bit (ORCPT ); Tue, 19 Apr 2016 10:38:43 -0400 From: Michal Nazarewicz To: Andrzej Pietrasiewicz , Alan Stern Cc: Ivaylo Dimitrov , Tony Lindgren , linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, Felipe Balbi , Bin Liu , pali.rohar@gmail.com Subject: Re: [PATCH] usb: f_mass_storage: test whether thread is running before starting another In-Reply-To: <5714A852.2040705@samsung.com> Organization: http://mina86.com/ References: <5714A852.2040705@samsung.com> User-Agent: Notmuch/0.19+53~g2e63a09 (http://notmuchmail.org) Emacs/25.1.50.1 (x86_64-unknown-linux-gnu) Face: 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 X-Face: -TR8(rDTHy/(xl?SfWd1|3:TTgDIatE^t'vop%*gVg[kn$t{EpK(P"VQ=~T2#ysNmJKN$"yTRLB4YQs$4{[.]Fc1)*O]3+XO^oXM>Q#b^ix,O)Zbn)q[y06$`e3?C)`CwR9y5riE=fv^X@x$y?D:XO6L&x4f-}}I4=VRNwiA^t1-ZrVK^07.Pi/57c_du'& X-PGP: 50751FF4 X-PGP-FP: AC1F 5F5C D418 88F8 CC84 5858 2060 4012 5075 1FF4 X-Hashcash: 1:20:160419:felipe.balbi@linux.intel.com::Arevc7j/m3vjgeqp:0000000000000000000000000000000000W3y X-Hashcash: 1:20:160419:pali.rohar@gmail.com::KbdHw5efNEv5cK4B:00000000000000000000000000000000000000000411R X-Hashcash: 1:20:160419:b-liu@ti.com::D1q1LmXj/vtgd9i4:000001P6Z X-Hashcash: 1:20:160419:linux-usb@vger.kernel.org::38Tn8SeOMyRVRmKA:0000000000000000000000000000000000002kS1 X-Hashcash: 1:20:160419:linux-kernel@vger.kernel.org::180RimGOKry39qkd:0000000000000000000000000000000001XCt X-Hashcash: 1:20:160419:tony@atomide.com::3L4ifNESaj6CCpqS:06yXw X-Hashcash: 1:20:160419:ivo.g.dimitrov.75@gmail.com::iLgI02L+sgYG1nra:0000000000000000000000000000000000DutF X-Hashcash: 1:20:160419:stern@rowland.harvard.edu::gp49AnylIVLH/Nj4:000000000000000000000000000000000000304m X-Hashcash: 1:20:160419:andrzej.p@samsung.com::P9U9kL5ftBHEeoSf:00000000000000000000000000000000000000004R/+ Date: Tue, 19 Apr 2016 16:38:38 +0200 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 828 Lines: 28 On Mon, Apr 18 2016, Andrzej Pietrasiewicz wrote: > The function responsible for verifying if a symlink can be made is in > drivers/usb/gadget/configfs.c: config_usb_cfg_link() > > There is a comment from the author: > > * Also a function instance can only be linked once. > > This is the code fragment of interest: > > list_for_each_entry(f, &cfg->func_list, list) { > if (f->fi == fi) { > ret = -EEXIST; > goto out; > } > } Thanks for checking. This is exactly the kind of check I expected so checking for thread not being run multiple times is enough when configfs is in use. Legacy gadgets may still construct crazy configurations but I’d call that a bug in such legacy gadget. -- Best regards ミハウ “????????????????86” ナザレヴイツ «If at first you don’t succeed, give up skydiving»