From: Jason Lunz Date: Thu, 29 Mar 2007 08:20:31 +0000 (-0700) Subject: [PATCH] uml: fix LVM crash X-Git-Tag: v2.6.21-rc6~62 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=af84eab208916acad91f6342bbd57bc865caf150;p=pandora-kernel.git [PATCH] uml: fix LVM crash 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 Cc: Paolo 'Blaisorblade' Giarrusso Cc: Alasdair G Kergon Cc: Jens Axboe Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Reading git-diff-tree failed