From owner-svn-src-all@FreeBSD.ORG Wed Jan 14 19:54:59 2015 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 2D762E39; Wed, 14 Jan 2015 19:54:59 +0000 (UTC) Received: from mail.turbocat.net (mail.turbocat.net [IPv6:2a01:4f8:d16:4514::2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id E263A1A4; Wed, 14 Jan 2015 19:54:58 +0000 (UTC) Received: from laptop015.home.selasky.org (cm-176.74.213.204.customer.telag.net [176.74.213.204]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.turbocat.net (Postfix) with ESMTPSA id 590761FE022; Wed, 14 Jan 2015 20:54:56 +0100 (CET) Message-ID: <54B6C9BF.6010408@selasky.org> Date: Wed, 14 Jan 2015 20:55:43 +0100 From: Hans Petter Selasky User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:31.0) Gecko/20100101 Thunderbird/31.3.0 MIME-Version: 1.0 To: "Andrey V. Elsukov" , src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r277179 - in head/sys: dev/usb kern sys References: <201501141404.t0EE4UR7008401@svn.freebsd.org> <54B6AE1C.5010405@FreeBSD.org> In-Reply-To: <54B6AE1C.5010405@FreeBSD.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 14 Jan 2015 19:54:59 -0000 On 01/14/15 18:57, Andrey V. Elsukov wrote: > On 14.01.2015 17:04, Hans Petter Selasky wrote: >> Author: hselasky >> Date: Wed Jan 14 14:04:29 2015 >> New Revision: 277179 >> URL: https://svnweb.freebsd.org/changeset/base/277179 >> >> Log: >> Add a kernel function to delist our kernel character devices, so that >> the device name can be re-used right away in case we are destroying >> the character devices in the background. >> >> MFC after: 4 days >> Reported by: dchagin@ >> >> Modified: >> head/sys/dev/usb/usb_device.c >> head/sys/kern/kern_conf.c >> head/sys/sys/conf.h >> >> Modified: head/sys/dev/usb/usb_device.c >> ============================================================================== >> --- head/sys/dev/usb/usb_device.c Wed Jan 14 13:03:03 2015 (r277178) >> +++ head/sys/dev/usb/usb_device.c Wed Jan 14 14:04:29 2015 (r277179) >> @@ -2019,7 +2019,10 @@ usb_destroy_dev(struct usb_fs_privdata * >> usb_destroy_dev_sync(pd); >> return; >> } >> - >> + >> + /* make sure we can re-use the device name */ >> + delist_dev(pd->cdev); >> + >> USB_BUS_LOCK(bus); >> LIST_INSERT_HEAD(&bus->pd_cleanup_list, pd, pd_next); >> /* get cleanup going */ >> >> Modified: head/sys/kern/kern_conf.c >> ============================================================================== >> --- head/sys/kern/kern_conf.c Wed Jan 14 13:03:03 2015 (r277178) >> +++ head/sys/kern/kern_conf.c Wed Jan 14 14:04:29 2015 (r277179) >> @@ -1114,6 +1114,23 @@ destroy_devl(struct cdev *dev) >> } >> } >> >> +static void >> +delist_dev_locked(struct cdev *dev) >> +{ >> + struct cdev *child; >> + devfs_destroy(dev); >> + LIST_FOREACH(child, &dev->si_children, si_siblings) >> + delist_dev_locked(child); >> +} > > It looks a bit strange. First you call destroy(dev), then you are trying > enumerate its children. It is ok? > Hi, Maybe you misread dev_destroy() with devfs_destroy(). devfs_destroy() only clears a flag bit, so that the devfs system does no longer show the device and the duplicate device check done when you create a new character device is not seeing the yet-to-be destroyed device. It should be OK from what I can see and have tested. --HPS