From patchwork Sat Jun 3 06:13:54 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 13266075 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8F1B6C7EE24 for ; Sat, 3 Jun 2023 06:13:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231589AbjFCGN6 (ORCPT ); Sat, 3 Jun 2023 02:13:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34852 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229523AbjFCGN4 (ORCPT ); Sat, 3 Jun 2023 02:13:56 -0400 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2C210E59 for ; Fri, 2 Jun 2023 23:13:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1685772835; x=1717308835; h=subject:from:to:cc:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=2Sru+PZzAiBMACd6GX9GYf+KilWjQZ3NHiyt4Y0GtYg=; b=BuniVuKSisyvzWGICTTpdgx89tYWlehowUPtBrMowmjjecg1B5J/8Jli 9jwk03V1n8AkA9AL3DiBWMvXSwAR0k0oUcz8rmw8ENqhwZ3LJWqlScPID ycEJWlTX2fjXzCpqyy5nKPjSk1tbptSFf5Ilcgqht5ucJKfcoEk1tQk7C CLAS8IcwSPVOmeJMDTBOKeTLSTkgKzFd3DgSxiBKN9XauC0wByhjavqUN UM4NX4LdMKYqwOs1//Z+AcDsjCNc9jKfX8LrDC60bT+OABHZ9YHHvrFlU YheoqyK2N58I2xsoqQ7ywCiUsdZqRZmDtyKROdSx9tYVbugeScFdMHc/v A==; X-IronPort-AV: E=McAfee;i="6600,9927,10729"; a="442417593" X-IronPort-AV: E=Sophos;i="6.00,215,1681196400"; d="scan'208";a="442417593" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Jun 2023 23:13:54 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10729"; a="711211563" X-IronPort-AV: E=Sophos;i="6.00,215,1681196400"; d="scan'208";a="711211563" Received: from rjkoval-mobl.amr.corp.intel.com (HELO dwillia2-xfh.jf.intel.com) ([10.212.230.247]) by fmsmga007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Jun 2023 23:13:54 -0700 Subject: [PATCH 1/4] dax: Fix dax_mapping_release() use after free From: Dan Williams To: nvdimm@lists.linux.dev Cc: linux-cxl@vger.kernel.org Date: Fri, 02 Jun 2023 23:13:54 -0700 Message-ID: <168577283412.1672036.16111545266174261446.stgit@dwillia2-xfh.jf.intel.com> In-Reply-To: <168577282846.1672036.13848242151310480001.stgit@dwillia2-xfh.jf.intel.com> References: <168577282846.1672036.13848242151310480001.stgit@dwillia2-xfh.jf.intel.com> User-Agent: StGit/0.18-3-g996c MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org A CONFIG_DEBUG_KOBJECT_RELEASE test of removing a device-dax region provider (like modprobe -r dax_hmem) yields: kobject: 'mapping0' (ffff93eb460e8800): kobject_release, parent 0000000000000000 (delayed 2000) [..] DEBUG_LOCKS_WARN_ON(1) WARNING: CPU: 23 PID: 282 at kernel/locking/lockdep.c:232 __lock_acquire+0x9fc/0x2260 [..] RIP: 0010:__lock_acquire+0x9fc/0x2260 [..] Call Trace: [..] lock_acquire+0xd4/0x2c0 ? ida_free+0x62/0x130 _raw_spin_lock_irqsave+0x47/0x70 ? ida_free+0x62/0x130 ida_free+0x62/0x130 dax_mapping_release+0x1f/0x30 device_release+0x36/0x90 kobject_delayed_cleanup+0x46/0x150 Due to attempting ida_free() on an ida object that has already been freed. Devices typically only hold a reference on their parent while registered. If a child needs a parent object to complete its release it needs to hold a reference that it drops from its release callback. Arrange for a dax_mapping to pin its parent dev_dax instance until dax_mapping_release(). Fixes: 0b07ce872a9e ("device-dax: introduce 'mapping' devices") Signed-off-by: Dan Williams Reviewed-by: Ira Weiny Reviewed-by: Fan Ni Reviewed-by: Dave Jiang --- drivers/dax/bus.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index 227800053309..aee695f86b44 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -635,10 +635,12 @@ EXPORT_SYMBOL_GPL(alloc_dax_region); static void dax_mapping_release(struct device *dev) { struct dax_mapping *mapping = to_dax_mapping(dev); - struct dev_dax *dev_dax = to_dev_dax(dev->parent); + struct device *parent = dev->parent; + struct dev_dax *dev_dax = to_dev_dax(parent); ida_free(&dev_dax->ida, mapping->id); kfree(mapping); + put_device(parent); } static void unregister_dax_mapping(void *data) @@ -778,6 +780,7 @@ static int devm_register_dax_mapping(struct dev_dax *dev_dax, int range_id) dev = &mapping->dev; device_initialize(dev); dev->parent = &dev_dax->dev; + get_device(dev->parent); dev->type = &dax_mapping_type; dev_set_name(dev, "mapping%d", mapping->id); rc = device_add(dev); From patchwork Sat Jun 3 06:13:59 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 13266076 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 775E5C7EE24 for ; Sat, 3 Jun 2023 06:14:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231621AbjFCGOC (ORCPT ); Sat, 3 Jun 2023 02:14:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34872 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229523AbjFCGOB (ORCPT ); Sat, 3 Jun 2023 02:14:01 -0400 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B27FBE5A for ; Fri, 2 Jun 2023 23:14:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1685772840; x=1717308840; h=subject:from:to:cc:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=FZ29ASs5+8CWYl1hUfDTQ0pBL9/BQYO8+XxZeO/2ZBY=; b=JHIE7DmTI0RcoKMP4/HmMOa7iDsdHs/+moOBEzJNVbvU1Bbj51uo2ncJ H8bhPUl9fP1KRKWgzqHdyolp6YKWD8H9RGVcs/I3RjbZUoI0A8oCVT6ZO thLAU4eDMy4fXyhC9ahDhT5fcAQRmsbOFXCQlwE5gjmHrOGgP+yrZ0r/c FPg6bF0hcBzOx/ct5ZqpKk78kuOX8xwqa/X39Ej5Ts7wcXvT5Zxy6cX0j IIyGUpZHEIlvJsj4HmqNtcvkv1h7ussNqJ1nK9eT3LCBSfS52FQQ1f4bI Fsc5aW4DuGM/pSlASOZU0FcswXv7JFpe4p+RUjcch/+QlXZBkwW/ZcGUv A==; X-IronPort-AV: E=McAfee;i="6600,9927,10729"; a="442417605" X-IronPort-AV: E=Sophos;i="6.00,215,1681196400"; d="scan'208";a="442417605" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Jun 2023 23:14:00 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10729"; a="711211566" X-IronPort-AV: E=Sophos;i="6.00,215,1681196400"; d="scan'208";a="711211566" Received: from rjkoval-mobl.amr.corp.intel.com (HELO dwillia2-xfh.jf.intel.com) ([10.212.230.247]) by fmsmga007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Jun 2023 23:14:00 -0700 Subject: [PATCH 2/4] dax: Use device_unregister() in unregister_dax_mapping() From: Dan Williams To: nvdimm@lists.linux.dev Cc: linux-cxl@vger.kernel.org Date: Fri, 02 Jun 2023 23:13:59 -0700 Message-ID: <168577283989.1672036.7777592498865470652.stgit@dwillia2-xfh.jf.intel.com> In-Reply-To: <168577282846.1672036.13848242151310480001.stgit@dwillia2-xfh.jf.intel.com> References: <168577282846.1672036.13848242151310480001.stgit@dwillia2-xfh.jf.intel.com> User-Agent: StGit/0.18-3-g996c MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org Replace an open-coded device_unregister() sequence with the helper. Signed-off-by: Dan Williams Reviewed-by: Ira Weiny Reviewed-by: Fan Ni Reviewed-by: Dave Jiang --- drivers/dax/bus.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index aee695f86b44..c99ea08aafc3 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -657,8 +657,7 @@ static void unregister_dax_mapping(void *data) dev_dax->ranges[mapping->range_id].mapping = NULL; mapping->range_id = -1; - device_del(dev); - put_device(dev); + device_unregister(dev); } static struct dev_dax_range *get_dax_range(struct device *dev) From patchwork Sat Jun 3 06:14:05 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 13266077 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 702ACC77B73 for ; Sat, 3 Jun 2023 06:14:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229523AbjFCGOI (ORCPT ); Sat, 3 Jun 2023 02:14:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34894 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231604AbjFCGOH (ORCPT ); Sat, 3 Jun 2023 02:14:07 -0400 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C3FEAE58 for ; Fri, 2 Jun 2023 23:14:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1685772846; x=1717308846; h=subject:from:to:cc:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=M1v4TiCX8AvusZkEJT8GFuAqlj18O4sl+0gBX3a0sRk=; b=UKP8e6SMEkDuZNdqWC8IzGSSvHEqGSXf3IZY219GOKNpnIiQu1epLa+R 0t6iWsewa6VgM2IPRm2ty8EJXzYOdGj7io8CXUqc1rCb2BIT9gtnLPpXf JXDHNvSkt2jvR9gSL+dvjT6KxjGZQWL82kGuu/VrN1ag20Nh90RV8C2yA YOx7J3cvLVTjfOnBY+Shx5NNpsuMDvsoSvomM/iTfTlOHKf0A5TNcA+CO anY1kL85izjqYSmHJO/OqAjaAtFFFxUDWwjGzp5IVsSR8jH2JqrybEd3g Eksxr0V8NRMRqfyt7+qo2zEDH0wPqaXEGNR+ueefhxKBYUj8ICmJ31/KP Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10729"; a="442417632" X-IronPort-AV: E=Sophos;i="6.00,215,1681196400"; d="scan'208";a="442417632" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Jun 2023 23:14:06 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10729"; a="711211576" X-IronPort-AV: E=Sophos;i="6.00,215,1681196400"; d="scan'208";a="711211576" Received: from rjkoval-mobl.amr.corp.intel.com (HELO dwillia2-xfh.jf.intel.com) ([10.212.230.247]) by fmsmga007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Jun 2023 23:14:06 -0700 Subject: [PATCH 3/4] dax: Introduce alloc_dev_dax_id() From: Dan Williams To: nvdimm@lists.linux.dev Cc: Yongqiang Liu , Paul Cassella , Ira Weiny , linux-cxl@vger.kernel.org Date: Fri, 02 Jun 2023 23:14:05 -0700 Message-ID: <168577284563.1672036.13493034988900989554.stgit@dwillia2-xfh.jf.intel.com> In-Reply-To: <168577282846.1672036.13848242151310480001.stgit@dwillia2-xfh.jf.intel.com> References: <168577282846.1672036.13848242151310480001.stgit@dwillia2-xfh.jf.intel.com> User-Agent: StGit/0.18-3-g996c MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org The reference counting of dax_region objects is needlessly complicated, has lead to confusion [1], and has hidden a bug [2]. Towards cleaning up that mess introduce alloc_dev_dax_id() to minimize the holding of a dax_region reference to only what dev_dax_release() needs, the dax_region->ida. Part of the reason for the mess was the design to dereference a dax_region in all cases in free_dev_dax_id() even if the id was statically assigned by the upper level dax_region driver. Remove the need to call "is_static(dax_region)" by tracking whether the id is dynamic directly in the dev_dax instance itself. With that flag the dax_region pinning and release per dev_dax instance can move to alloc_dev_dax_id() and free_dev_dax_id() respectively. A follow-on cleanup address the unnecessary references in the dax_region setup and drivers. Fixes: 0f3da14a4f05 ("device-dax: introduce 'seed' devices") Link: http://lore.kernel.org/r/20221203095858.612027-1-liuyongqiang13@huawei.com [1] Link: http://lore.kernel.org/r/3cf0890b-4eb0-e70e-cd9c-2ecc3d496263@hpe.com [2] Reported-by: Yongqiang Liu Reported-by: Paul Cassella Reported-by: Ira Weiny Signed-off-by: Dan Williams Reviewed-by: Ira Weiny --- drivers/dax/bus.c | 56 +++++++++++++++++++++++++++------------------ drivers/dax/dax-private.h | 4 ++- 2 files changed, 37 insertions(+), 23 deletions(-) diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index c99ea08aafc3..a4cc3eca774f 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -446,18 +446,34 @@ static void unregister_dev_dax(void *dev) put_device(dev); } +static void dax_region_free(struct kref *kref) +{ + struct dax_region *dax_region; + + dax_region = container_of(kref, struct dax_region, kref); + kfree(dax_region); +} + +void dax_region_put(struct dax_region *dax_region) +{ + kref_put(&dax_region->kref, dax_region_free); +} +EXPORT_SYMBOL_GPL(dax_region_put); + /* a return value >= 0 indicates this invocation invalidated the id */ static int __free_dev_dax_id(struct dev_dax *dev_dax) { - struct dax_region *dax_region = dev_dax->region; struct device *dev = &dev_dax->dev; + struct dax_region *dax_region; int rc = dev_dax->id; device_lock_assert(dev); - if (is_static(dax_region) || dev_dax->id < 0) + if (!dev_dax->dyn_id || dev_dax->id < 0) return -1; + dax_region = dev_dax->region; ida_free(&dax_region->ida, dev_dax->id); + dax_region_put(dax_region); dev_dax->id = -1; return rc; } @@ -473,6 +489,20 @@ static int free_dev_dax_id(struct dev_dax *dev_dax) return rc; } +static int alloc_dev_dax_id(struct dev_dax *dev_dax) +{ + struct dax_region *dax_region = dev_dax->region; + int id; + + id = ida_alloc(&dax_region->ida, GFP_KERNEL); + if (id < 0) + return id; + kref_get(&dax_region->kref); + dev_dax->dyn_id = true; + dev_dax->id = id; + return id; +} + static ssize_t delete_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { @@ -560,20 +590,6 @@ static const struct attribute_group *dax_region_attribute_groups[] = { NULL, }; -static void dax_region_free(struct kref *kref) -{ - struct dax_region *dax_region; - - dax_region = container_of(kref, struct dax_region, kref); - kfree(dax_region); -} - -void dax_region_put(struct dax_region *dax_region) -{ - kref_put(&dax_region->kref, dax_region_free); -} -EXPORT_SYMBOL_GPL(dax_region_put); - static void dax_region_unregister(void *region) { struct dax_region *dax_region = region; @@ -1297,12 +1313,10 @@ static const struct attribute_group *dax_attribute_groups[] = { static void dev_dax_release(struct device *dev) { struct dev_dax *dev_dax = to_dev_dax(dev); - struct dax_region *dax_region = dev_dax->region; struct dax_device *dax_dev = dev_dax->dax_dev; put_dax(dax_dev); free_dev_dax_id(dev_dax); - dax_region_put(dax_region); kfree(dev_dax->pgmap); kfree(dev_dax); } @@ -1326,6 +1340,7 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data) if (!dev_dax) return ERR_PTR(-ENOMEM); + dev_dax->region = dax_region; if (is_static(dax_region)) { if (dev_WARN_ONCE(parent, data->id < 0, "dynamic id specified to static region\n")) { @@ -1341,13 +1356,11 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data) goto err_id; } - rc = ida_alloc(&dax_region->ida, GFP_KERNEL); + rc = alloc_dev_dax_id(dev_dax); if (rc < 0) goto err_id; - dev_dax->id = rc; } - dev_dax->region = dax_region; dev = &dev_dax->dev; device_initialize(dev); dev_set_name(dev, "dax%d.%d", dax_region->id, dev_dax->id); @@ -1388,7 +1401,6 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data) dev_dax->target_node = dax_region->target_node; dev_dax->align = dax_region->align; ida_init(&dev_dax->ida); - kref_get(&dax_region->kref); inode = dax_inode(dax_dev); dev->devt = inode->i_rdev; diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h index 1c974b7caae6..afcada6fd2ed 100644 --- a/drivers/dax/dax-private.h +++ b/drivers/dax/dax-private.h @@ -52,7 +52,8 @@ struct dax_mapping { * @region - parent region * @dax_dev - core dax functionality * @target_node: effective numa node if dev_dax memory range is onlined - * @id: ida allocated id + * @dyn_id: is this a dynamic or statically created instance + * @id: ida allocated id when the dax_region is not static * @ida: mapping id allocator * @dev - device core * @pgmap - pgmap for memmap setup / lifetime (driver owned) @@ -64,6 +65,7 @@ struct dev_dax { struct dax_device *dax_dev; unsigned int align; int target_node; + bool dyn_id; int id; struct ida ida; struct device dev; From patchwork Sat Jun 3 06:14:11 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 13266078 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B16D0C7EE24 for ; Sat, 3 Jun 2023 06:14:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229986AbjFCGOQ (ORCPT ); Sat, 3 Jun 2023 02:14:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34922 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231604AbjFCGON (ORCPT ); Sat, 3 Jun 2023 02:14:13 -0400 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7A904E59 for ; 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a="711211579" X-IronPort-AV: E=Sophos;i="6.00,215,1681196400"; d="scan'208";a="711211579" Received: from rjkoval-mobl.amr.corp.intel.com (HELO dwillia2-xfh.jf.intel.com) ([10.212.230.247]) by fmsmga007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Jun 2023 23:14:12 -0700 Subject: [PATCH 4/4] dax: Cleanup extra dax_region references From: Dan Williams To: nvdimm@lists.linux.dev Cc: Ira Weiny , linux-cxl@vger.kernel.org Date: Fri, 02 Jun 2023 23:14:11 -0700 Message-ID: <168577285161.1672036.8111253437794419696.stgit@dwillia2-xfh.jf.intel.com> In-Reply-To: <168577282846.1672036.13848242151310480001.stgit@dwillia2-xfh.jf.intel.com> References: <168577282846.1672036.13848242151310480001.stgit@dwillia2-xfh.jf.intel.com> User-Agent: StGit/0.18-3-g996c MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org Now that free_dev_dax_id() internally manages the references it needs the extra references taken by the dax_region drivers are not needed. Reported-by: Ira Weiny Signed-off-by: Dan Williams Reviewed-by: Ira Weiny Reviewed-by: Fan Ni Reviewed-by: Dave Jiang --- drivers/dax/bus.c | 4 +--- drivers/dax/bus.h | 1 - drivers/dax/cxl.c | 8 +------- drivers/dax/hmem/hmem.c | 8 +------- drivers/dax/pmem.c | 7 +------ 5 files changed, 4 insertions(+), 24 deletions(-) diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index a4cc3eca774f..0ee96e6fc426 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -454,11 +454,10 @@ static void dax_region_free(struct kref *kref) kfree(dax_region); } -void dax_region_put(struct dax_region *dax_region) +static void dax_region_put(struct dax_region *dax_region) { kref_put(&dax_region->kref, dax_region_free); } -EXPORT_SYMBOL_GPL(dax_region_put); /* a return value >= 0 indicates this invocation invalidated the id */ static int __free_dev_dax_id(struct dev_dax *dev_dax) @@ -641,7 +640,6 @@ struct dax_region *alloc_dax_region(struct device *parent, int region_id, return NULL; } - kref_get(&dax_region->kref); if (devm_add_action_or_reset(parent, dax_region_unregister, dax_region)) return NULL; return dax_region; diff --git a/drivers/dax/bus.h b/drivers/dax/bus.h index 8cd79ab34292..bdbf719df5c5 100644 --- a/drivers/dax/bus.h +++ b/drivers/dax/bus.h @@ -9,7 +9,6 @@ struct dev_dax; struct resource; struct dax_device; struct dax_region; -void dax_region_put(struct dax_region *dax_region); /* dax bus specific ioresource flags */ #define IORESOURCE_DAX_STATIC BIT(0) diff --git a/drivers/dax/cxl.c b/drivers/dax/cxl.c index ccdf8de85bd5..8bc9d04034d6 100644 --- a/drivers/dax/cxl.c +++ b/drivers/dax/cxl.c @@ -13,7 +13,6 @@ static int cxl_dax_region_probe(struct device *dev) struct cxl_region *cxlr = cxlr_dax->cxlr; struct dax_region *dax_region; struct dev_dax_data data; - struct dev_dax *dev_dax; if (nid == NUMA_NO_NODE) nid = memory_add_physaddr_to_nid(cxlr_dax->hpa_range.start); @@ -28,13 +27,8 @@ static int cxl_dax_region_probe(struct device *dev) .id = -1, .size = range_len(&cxlr_dax->hpa_range), }; - dev_dax = devm_create_dev_dax(&data); - if (IS_ERR(dev_dax)) - return PTR_ERR(dev_dax); - /* child dev_dax instances now own the lifetime of the dax_region */ - dax_region_put(dax_region); - return 0; + return PTR_ERR_OR_ZERO(devm_create_dev_dax(&data)); } static struct cxl_driver cxl_dax_region_driver = { diff --git a/drivers/dax/hmem/hmem.c b/drivers/dax/hmem/hmem.c index e5fe8b39fb94..5d2ddef0f8f5 100644 --- a/drivers/dax/hmem/hmem.c +++ b/drivers/dax/hmem/hmem.c @@ -16,7 +16,6 @@ static int dax_hmem_probe(struct platform_device *pdev) struct dax_region *dax_region; struct memregion_info *mri; struct dev_dax_data data; - struct dev_dax *dev_dax; /* * @region_idle == true indicates that an administrative agent @@ -38,13 +37,8 @@ static int dax_hmem_probe(struct platform_device *pdev) .id = -1, .size = region_idle ? 0 : range_len(&mri->range), }; - dev_dax = devm_create_dev_dax(&data); - if (IS_ERR(dev_dax)) - return PTR_ERR(dev_dax); - /* child dev_dax instances now own the lifetime of the dax_region */ - dax_region_put(dax_region); - return 0; + return PTR_ERR_OR_ZERO(devm_create_dev_dax(&data)); } static struct platform_driver dax_hmem_driver = { diff --git a/drivers/dax/pmem.c b/drivers/dax/pmem.c index f050ea78bb83..ae0cb113a5d3 100644 --- a/drivers/dax/pmem.c +++ b/drivers/dax/pmem.c @@ -13,7 +13,6 @@ static struct dev_dax *__dax_pmem_probe(struct device *dev) int rc, id, region_id; resource_size_t offset; struct nd_pfn_sb *pfn_sb; - struct dev_dax *dev_dax; struct dev_dax_data data; struct nd_namespace_io *nsio; struct dax_region *dax_region; @@ -65,12 +64,8 @@ static struct dev_dax *__dax_pmem_probe(struct device *dev) .pgmap = &pgmap, .size = range_len(&range), }; - dev_dax = devm_create_dev_dax(&data); - /* child dev_dax instances now own the lifetime of the dax_region */ - dax_region_put(dax_region); - - return dev_dax; + return devm_create_dev_dax(&data); } static int dax_pmem_probe(struct device *dev)