From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Snitzer Date: Wed, 17 Mar 2004 01:47:37 +0000 Subject: Re: Non-hardware devices like loop: another idea Message-Id: <20040316184737.B14721@lnxi.com> List-Id: References: <200403122003.00557.patrakov@ums.usu.ru> In-Reply-To: <200403122003.00557.patrakov@ums.usu.ru> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-hotplug@vger.kernel.org What if you configure this options into the kernel, e.g.: CONFIG_BLK_DEV_LOOP=y CONFIG_TUN=y ... etc ... rather than building all non-hardware backed devices as modules? Relying on them being modules seems quite restrictive. Mike On Fri, Mar 12 2004 at 08:03, Alexander E. Patrakov wrote: > Recently I stated that I am working on solution to the "chicken-and-egg" > problem related to devices like /dev/loop*, /dev/nbd*, /dev/ppp and so on, > which require no hardware and therefore are not detectable by the hotplug > scripts. > > My (bad) idea was to include the sysfs entries that would appear after loading > the module in the module itself by means of the MODULE_INFO macro, and then > modify depmod to populate /lib/modules//sys and use it to > populate /dev with the corresponding entries (the UDEV_TEST environment > variable already allows us to override the location of the sysfs directory). > Then the char-major magic will load these modules on demand. > > I have a proof-of-concept implementation (will mail it here if there is any > demand). The list of files altered: > > module-init-tools-3.0-pre5/depmod.c > linux-2.6.4/include/linux/module.h > linux-2.6.4/drivers/block/loop.c > linux-2.6.4/drivers/char/rtc.c > linux-2.6.4/drivers/net/ppp_generic.c > ...and my udev initscript > > This is not a real, but a proof-of-concept implementation because there are > much more such non-hardware modules. This works, > > --- BUT! --- > > I found my implementation rather clumsy and while implementing it I decided > that it would be better to just mark such modules and modprobe tham all, and > make the hotplug script modprobe other stuff. I decided to start implementing > such mark... and found that it has already been done, so actually no patches > are needed except for the udev initscript! > > I am talking about /lib/modules//modules.alias. > > The simple idea is to grep this file (and probably /etc/modprobe.conf also) > for lines containing char-major and block-major. The list pretty much > coincides with the list of non-hardware-related modules that nevertheless > provide devices. > > Does anyone care to include this into the future release of udev? > > -- > Alexander E. Patrakov > > > ------------------------------------------------------- > This SF.Net email is sponsored by: IBM Linux Tutorials > Free Linux tutorial presented by Daniel Robbins, President and CEO of > GenToo technologies. Learn everything from fundamentals to system > administration.http://ads.osdn.com/?ad_id70&alloc_id638&op=click > _______________________________________________ > Linux-hotplug-devel mailing list http://linux-hotplug.sourceforge.net > Linux-hotplug-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel > ------------------------------------------------------- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id70&alloc_id638&op=click _______________________________________________ Linux-hotplug-devel mailing list http://linux-hotplug.sourceforge.net Linux-hotplug-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel