Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261907AbUKPF60 (ORCPT ); Tue, 16 Nov 2004 00:58:26 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261909AbUKPF5b (ORCPT ); Tue, 16 Nov 2004 00:57:31 -0500 Received: from mail.kroah.org ([69.55.234.183]:42459 "EHLO perch.kroah.org") by vger.kernel.org with ESMTP id S261907AbUKPFz3 (ORCPT ); Tue, 16 Nov 2004 00:55:29 -0500 Date: Mon, 15 Nov 2004 21:52:24 -0800 From: Greg KH To: Dmitry Torokhov Cc: Tejun Heo , LKML Subject: Re: [PATCH 2.6.10-rc1 2/5] driver-model: bus_recan_devices() locking fix Message-ID: <20041116055224.GF29328@kroah.com> References: <20041104185826.GA17756@kroah.com> <20041110004052.GB8672@kroah.com> <200411092317.33300.dtor_core@ameritech.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200411092317.33300.dtor_core@ameritech.net> User-Agent: Mutt/1.5.6i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1869 Lines: 56 On Tue, Nov 09, 2004 at 11:17:31PM -0500, Dmitry Torokhov wrote: > On Tuesday 09 November 2004 07:40 pm, Greg KH wrote: > > > I think we just have lay down the rules that one needs to get a reference > > > to an object in the following cases: > > > - object creation (first reference) > > > - linking some other object to the object in question. Every link to the > > > ? object should increase reference count. > > > - before passing object to another thread of execution to guarantee that > > > ? the object will live long enough for both threads. > > > > The rules are defined. ?See my OLS 2004 paper on krefs for details. > > > > So that means you will patches like the one below, right? > > diff -Nru a/drivers/base/driver.c b/drivers/base/driver.c > --- a/drivers/base/driver.c 2004-11-09 23:16:43 -05:00 > +++ b/drivers/base/driver.c 2004-11-09 23:16:43 -05:00 > @@ -26,13 +26,7 @@ > > int driver_create_file(struct device_driver * drv, struct driver_attribute * attr) > { > - int error; > - if (get_driver(drv)) { > - error = sysfs_create_file(&drv->kobj, &attr->attr); > - put_driver(drv); > - } else > - error = -EINVAL; > - return error; > + return sysfs_create_file(&drv->kobj, &attr->attr); > } > > > @@ -44,10 +38,7 @@ > > void driver_remove_file(struct device_driver * drv, struct driver_attribute * attr) > { > - if (get_driver(drv)) { > - sysfs_remove_file(&drv->kobj, &attr->attr); > - put_driver(drv); > - } > + sysfs_remove_file(&drv->kobj, &attr->attr); > } While not totally necessary, the current code is safe :) I'll ask Pat about this next time I see him. thanks, greg k-h - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/