Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934680Ab2J3VRH (ORCPT ); Tue, 30 Oct 2012 17:17:07 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:55293 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934532Ab2J3VRD (ORCPT ); Tue, 30 Oct 2012 17:17:03 -0400 Date: Tue, 30 Oct 2012 21:17:01 +0000 From: Al Viro To: Jeff Moyer Cc: linux-kernel@vger.kernel.org, David Howells , Chris Mason , Steve French , Mark Fasheh , Joel Becker , Matthew Wilcox , linux-afs@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-cifs@vger.kernel.org, samba-technical@lists.samba.org, ocfs2-devel@oss.oracle.com Subject: Re: [patch 05/10] vfs: pass data to alloc_inode super operation Message-ID: <20121030211701.GC2616@ZenIV.linux.org.uk> References: <1351628084-29358-1-git-send-email-jmoyer@redhat.com> <1351628084-29358-8-git-send-email-jmoyer@redhat.com> <20121030205142.GB2616@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20121030205142.GB2616@ZenIV.linux.org.uk> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1437 Lines: 35 On Tue, Oct 30, 2012 at 08:51:42PM +0000, Al Viro wrote: > On Tue, Oct 30, 2012 at 04:14:39PM -0400, Jeff Moyer wrote: > > This patch passes a data pointer along to the alloc_inode > > super_operations function. The value will initially be used by > > bdev_alloc_inode to allocate the bdev_inode on the same numa > > node as the device to which it is tied. > > Yecchhh... > > > -static struct inode *bdev_alloc_inode(struct super_block *sb) > > +static struct inode *bdev_alloc_inode(struct super_block *sb, void *data) > > { > > - struct bdev_inode *ei = kmem_cache_alloc(bdev_cachep, GFP_KERNEL); > > + struct bdev_inode *ei; > > + int partno; > > + int node; > > + > > + if (data) { > > + struct gendisk *disk; > > + dev_t dev = *(dev_t *)data; > > + disk = get_gendisk(dev, &partno); > > + node = disk->node_id; BTW, speaking of other reasons this is FUBAR - mknod a block device node for something that doesn't exist and try to open it. struct block_device lifetime is not limited to that of struct gendisk; it can be allocated before gendisk is there. Moreover, with static /dev and demand-loaded modules this will be the normal scenario. IOW, this is completely misguided. -- 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/