From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934162AbXC0Sbk (ORCPT ); Tue, 27 Mar 2007 14:31:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S934161AbXC0Sbf (ORCPT ); Tue, 27 Mar 2007 14:31:35 -0400 Received: from [198.99.130.12] ([198.99.130.12]:45441 "EHLO saraswathi.solana.com" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S934159AbXC0SbG (ORCPT ); Tue, 27 Mar 2007 14:31:06 -0400 Date: Tue, 27 Mar 2007 14:27:50 -0400 From: Jeff Dike To: Andrew Morton Cc: Jason Lunz , LKML , uml-devel Subject: [PATCH 6/6] UML - Fix LVM crash Message-ID: <20070327182750.GA8421@c2.user-mode-linux.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org From: Jason Lunz Permit lvm to create logical volumes without crashing UML. When device-mapper's DM_DEV_CREATE_CMD ioctl is called to create a new device, dev_create()->dm_create()->alloc_dev()-> blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY) is called. blk_queue_bounce_limit(BLK_BOUNCE_ANY) calls init_emergency_isa_pool() if blk_max_pfn < blk_max_low_pfn. This is the case on UML, but init_emergency_isa_pool() hits BUG_ON(!isa_page_pool) because there doesn't seem to be a dma zone on UML for mempool_create() to allocate from. Most architectures seem to have max_low_pfn == max_pfn, but UML doesn't because of the uml_reserved chunk it keeps for itself. From what I can see, max_pfn and max_low_pfn don't get much use after the bootmem-allocator stops being used anyway, except that they initialize the block layer's blk_max_low_pfn/blk_max_pfn. This ensures init_emergency_isa_pool() doesn't crash uml in this situation by setting max_low_pfn == max_pfn in mem_init(). Signed-off-by: Jason Lunz Signed-off-by: Jeff Dike --- arch/um/kernel/mem.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) Index: linux-2.6.21-mm/arch/um/kernel/mem.c =================================================================== --- linux-2.6.21-mm.orig/arch/um/kernel/mem.c 2007-03-27 12:25:10.000000000 -0400 +++ linux-2.6.21-mm/arch/um/kernel/mem.c 2007-03-27 12:58:36.000000000 -0400 @@ -64,8 +64,6 @@ static void setup_highmem(unsigned long void mem_init(void) { - max_low_pfn = (high_physmem - uml_physmem) >> PAGE_SHIFT; - /* clear the zero-page */ memset((void *) empty_zero_page, 0, PAGE_SIZE); @@ -80,6 +78,7 @@ void mem_init(void) /* this will put all low memory onto the freelists */ totalram_pages = free_all_bootmem(); + max_low_pfn = totalram_pages; #ifdef CONFIG_HIGHMEM totalhigh_pages = highmem >> PAGE_SHIFT; totalram_pages += totalhigh_pages;