Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 17 Nov 2002 16:56:43 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 17 Nov 2002 16:56:42 -0500 Received: from nat-pool-rdu.redhat.com ([66.187.233.200]:18309 "EHLO flossy.devel.redhat.com") by vger.kernel.org with ESMTP id ; Sun, 17 Nov 2002 16:56:39 -0500 Date: Sun, 17 Nov 2002 17:04:10 -0500 From: Doug Ledford To: Alexander Viro Cc: Linus Torvalds , Linux Kernel Mailing List , Linux Scsi Mailing List Subject: Re: Several Misc SCSI updates... Message-ID: <20021117220410.GI3280@redhat.com> Mail-Followup-To: Alexander Viro , Linus Torvalds , Linux Kernel Mailing List , Linux Scsi Mailing List References:

Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2872 Lines: 78 On Sun, Nov 17, 2002 at 04:55:26PM -0500, Alexander Viro wrote: > > > On Sun, 17 Nov 2002, Linus Torvalds wrote: > > > > > On Sun, 17 Nov 2002, Doug Ledford wrote: > > > > > > Won't work. module->live is what Rusty uses to indicate that the module > > > is in the process of unloading, which is when we *do* want the attempt to > > > module_get() to fail. > > > > That's fine, as long as "module_get()" is the only thing that cares. Just > > make it go "live" early as you indicate, and everybody should be happy. I > > certainly agree that it should be illegal to do more module_get()'s once > > we've already started unloading.. > > On the unload side it's OK. module_get() also breaks during _init_ and that's > the problem. IOW, you'll need to make every block device driver to set ->live > manually. Smells like a wrong API... This is the patch I just put into my tree (beware cut-n-paste breakage is in effect, but Linus should have the change in his tree momentarily anyway): diff -Nru a/kernel/module.c b/kernel/module.c --- a/kernel/module.c Sun Nov 17 17:02:48 2002 +++ b/kernel/module.c Sun Nov 17 17:02:48 2002 @@ -1058,6 +1058,15 @@ list_add(&mod->extable.list, &extables); spin_unlock_irq(&modlist_lock); + /* Note, setting the mod->live to 1 here is safe because we haven't + * linked the module into the system's kernel symbol table yet, + * which means that the only way any other kernel code can call + * into this module right now is if this module hands out entry + * pointers to the other code. We assume that no module hands out + * entry pointers to the rest of the kernel unless it is ready to + * have them used. + */ + mod->live = 1; /* Start the module */ ret = mod->init ? mod->init() : 0; if (ret < 0) { @@ -1070,9 +1079,10 @@ /* Mark it "live" so that they can force deletion later, and we don't keep getting woken on every decrement. */ - mod->live = 1; - } else + } else { + mod->live = 0; free_module(mod); + } up(&module_mutex); return ret; } @@ -1087,7 +1097,6 @@ mod->module_init = NULL; /* All ok! */ - mod->live = 1; up(&module_mutex); return 0; } -- Doug Ledford 919-754-3700 x44233 Red Hat, Inc. 1801 Varsity Dr. Raleigh, NC 27606 - 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/