From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756194AbcLNOiI (ORCPT ); Wed, 14 Dec 2016 09:38:08 -0500 Received: from mx2.suse.de ([195.135.220.15]:50617 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755859AbcLNOiG (ORCPT ); Wed, 14 Dec 2016 09:38:06 -0500 Date: Wed, 14 Dec 2016 15:38:02 +0100 From: Johannes Thumshirn To: Dan Williams Cc: linux-nvdimm@ml01.01.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/8] dax: add region-available-size attribute Message-ID: <20161214143802.GD6279@linux-x5ow.site> References: <148143770485.10950.13227732273892953675.stgit@dwillia2-desk3.amr.corp.intel.com> <148143771052.10950.7622110904173815243.stgit@dwillia2-desk3.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <148143771052.10950.7622110904173815243.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Dan, On Sat, Dec 10, 2016 at 10:28:30PM -0800, Dan Williams wrote: > In preparation for a facility that enables dax regions to be > sub-divided, introduce a 'dax/available_size' attribute. This attribute > appears under the parent device that registered the device-dax region, > and it assumes that the device-dax-core owns the driver-data for that > device. > > 'dax/available_size' adjusts dynamically as dax-device instances are > registered and unregistered. > > As a side effect of using __request_region() to reserve capacity from > the dax_region we now track pointers to those returned resources rather > than duplicating the passed in resource array. > > Signed-off-by: Dan Williams > --- [...] > +static const struct attribute_group *dax_region_attribute_groups[] = { > + &dax_region_attribute_group, > + NULL, > }; > > static struct inode *dax_alloc_inode(struct super_block *sb) > @@ -200,12 +251,27 @@ void dax_region_put(struct dax_region *dax_region) > } > EXPORT_SYMBOL_GPL(dax_region_put); > > + Stray extra newline? [...] > struct dax_region *alloc_dax_region(struct device *parent, int region_id, > struct resource *res, unsigned int align, void *addr, > unsigned long pfn_flags) > { > struct dax_region *dax_region; > > + if (dev_get_drvdata(parent)) { > + dev_WARN(parent, "dax core found drvdata already in use\n"); > + return NULL; > + } > + My first thought was, it might be interesting to see who already claimed the drvdata. Then I figured, how are multiple sub-regions of a dax-device supposed to work? What am I missing here? > if (!IS_ALIGNED(res->start, align) > || !IS_ALIGNED(resource_size(res), align)) > return NULL; > @@ -213,16 +279,26 @@ struct dax_region *alloc_dax_region(struct device *parent, int region_id, > dax_region = kzalloc(sizeof(*dax_region), GFP_KERNEL); > if (!dax_region) > return NULL; > - > - memcpy(&dax_region->res, res, sizeof(*res)); > + dev_set_drvdata(parent, dax_region); > + dax_region->res.name = dev_name(parent); > + dax_region->res.start = res->start; > + dax_region->res.end = res->end; > dax_region->pfn_flags = pfn_flags; > + mutex_init(&dax_region->lock); > kref_init(&dax_region->kref); > dax_region->id = region_id; > ida_init(&dax_region->ida); > dax_region->align = align; > dax_region->dev = parent; > dax_region->base = addr; > + if (sysfs_create_groups(&parent->kobj, dax_region_attribute_groups)) { > + kfree(dax_region); > + return NULL;; > + } > > + kref_get(&dax_region->kref); > + if (devm_add_action_or_reset(parent, dax_region_unregister, dax_region)) > + return NULL; > return dax_region; > } > EXPORT_SYMBOL_GPL(alloc_dax_region); [...] > @@ -568,28 +654,42 @@ struct dax_dev *devm_create_dax_dev(struct dax_region *dax_region, > struct cdev *cdev; > dev_t dev_t; > > - dax_dev = kzalloc(sizeof(*dax_dev) + sizeof(*res) * count, GFP_KERNEL); > + dax_dev = kzalloc(sizeof(*dax_dev), GFP_KERNEL); > if (!dax_dev) > return ERR_PTR(-ENOMEM); > > + dax_dev->res = kzalloc(sizeof(res) * count, GFP_KERNEL); dax_dev->res = kcalloc(sizeof(res), count, GFP_KERNEL); ? > + if (!dax_dev->res) > + goto err_res; > + Byte, Johannes