From patchwork Sun Apr 21 01:44:28 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pasha Tatashin X-Patchwork-Id: 10910437 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 54D8A1515 for ; Sun, 21 Apr 2019 01:44:37 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 468F028960 for ; Sun, 21 Apr 2019 01:44:37 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3A4522896D; Sun, 21 Apr 2019 01:44:37 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.7 required=2.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 97E3828960 for ; Sun, 21 Apr 2019 01:44:35 +0000 (UTC) Received: from [127.0.0.1] (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 8CCED2121797F; Sat, 20 Apr 2019 18:44:35 -0700 (PDT) X-Original-To: linux-nvdimm@lists.01.org Delivered-To: linux-nvdimm@lists.01.org Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=2607:f8b0:4864:20::844; helo=mail-qt1-x844.google.com; envelope-from=pasha.tatashin@soleen.com; receiver=linux-nvdimm@lists.01.org Received: from mail-qt1-x844.google.com (mail-qt1-x844.google.com [IPv6:2607:f8b0:4864:20::844]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id E2BA4211F9D74 for ; Sat, 20 Apr 2019 18:44:34 -0700 (PDT) Received: by mail-qt1-x844.google.com with SMTP id p20so8949092qtc.9 for ; Sat, 20 Apr 2019 18:44:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=soleen.com; s=google; h=from:to:subject:date:message-id:in-reply-to:references:mime-version :content-transfer-encoding; bh=CYN5iyU5BivsuLuaj0p6OjCQw7Id7vPwrKGL/YIcXb0=; b=Lx4n3eeQsd3DKBZFt1X+n0tHyvdxX9eMXlbGkCZXa5jPDl+R+bxvhnePCzuiVFH+jk di+Mp6Mfiv5tBZu3YjQsIuC9JNhQV5AoV/J9rAuT1n2Pzo9ukHrKDSQHkIHF92Mqzxql YvxHUk9CCjLHPwU2JfPC6Jb4K3eYzQaEOCweZDDMP3zNxsjvacM4Si4fbi0xJj8A+ZHM HRrrp8lKjP5UFpftK/lphzl+xQk7hG0nsmdRNOw9TAxyhOTDr3q5eE7aOoZRIevE2SJ1 IyWD1DfUU79PI1VB99cVVKjDHJ6TbNTIQlFTSgKgHQNPdqcPC2df8BsTeVhpEsSjlzIL cz1g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=CYN5iyU5BivsuLuaj0p6OjCQw7Id7vPwrKGL/YIcXb0=; b=YYKCPC/NgNm+1Gdfcr+24mqB618hj2xktMF4NpN7gd9zvIoIwd2BKzTHu16u5g02o3 mxVTycaygljUroO1naDYrW9YT8rTVo/BdjLMh1/TnWb9kqLyN4ej7MUR/U5HQT4LdbFQ njoGvoYBolrchPhX9xU6QGTO/7Vtwom3PSVqhhS/gxjs5E2LMUiE0xFkakjWtceyj7Fv AbGoVvNTEmEBi466Zvb8D4+BBU7DtnguMZ6WOr2C27H6InURVC9+r0UmOUsZsdHD77UD Qx8EL16csT6h54Qk0+acHXjiJ5KPXJW3lITfp2Ca6Ar73jhA0ikINzNze8ANs415MyL3 iUzA== X-Gm-Message-State: APjAAAW3P3Cx+iQDGCoG7FF8+dyqpOGfi9maVtXrGB9GYKprspT2/7FU OBB9JDh9FjEQFVc7BUTmlxjTnA== X-Google-Smtp-Source: APXvYqyGwfhqvlrszPLC8qN9m2XQDrZ+wKGZWzLF7GM7scRLtBDlMXL92I0fVQaBdczXZtyMg5jLVQ== X-Received: by 2002:ad4:430c:: with SMTP id c12mr10017920qvs.109.1555811074063; Sat, 20 Apr 2019 18:44:34 -0700 (PDT) Received: from localhost.localdomain (c-73-69-118-222.hsd1.nh.comcast.net. [73.69.118.222]) by smtp.gmail.com with ESMTPSA id u1sm1385218qtj.50.2019.04.20.18.44.32 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 20 Apr 2019 18:44:33 -0700 (PDT) From: Pavel Tatashin To: pasha.tatashin@soleen.com, jmorris@namei.org, sashal@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-nvdimm@lists.01.org, akpm@linux-foundation.org, mhocko@suse.com, dave.hansen@linux.intel.com, dan.j.williams@intel.com, keith.busch@intel.com, vishal.l.verma@intel.com, dave.jiang@intel.com, zwisler@kernel.org, thomas.lendacky@amd.com, ying.huang@intel.com, fengguang.wu@intel.com, bp@suse.de, bhelgaas@google.com, baiyaowei@cmss.chinamobile.com, tiwai@suse.de, jglisse@redhat.com Subject: [v2 1/2] device-dax: fix memory and resource leak if hotplug fails Date: Sat, 20 Apr 2019 21:44:28 -0400 Message-Id: <20190421014429.31206-2-pasha.tatashin@soleen.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190421014429.31206-1-pasha.tatashin@soleen.com> References: <20190421014429.31206-1-pasha.tatashin@soleen.com> MIME-Version: 1.0 X-BeenThere: linux-nvdimm@lists.01.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Linux-nvdimm developer list." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" X-Virus-Scanned: ClamAV using ClamSMTP When add_memory() function fails, the resource and the memory should be freed. Fixes: c221c0b0308f ("device-dax: "Hotplug" persistent memory for use like normal RAM") Signed-off-by: Pavel Tatashin --- drivers/dax/kmem.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c index a02318c6d28a..4c0131857133 100644 --- a/drivers/dax/kmem.c +++ b/drivers/dax/kmem.c @@ -66,8 +66,11 @@ int dev_dax_kmem_probe(struct device *dev) new_res->name = dev_name(dev); rc = add_memory(numa_node, new_res->start, resource_size(new_res)); - if (rc) + if (rc) { + release_resource(new_res); + kfree(new_res); return rc; + } return 0; } From patchwork Sun Apr 21 01:44:29 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pasha Tatashin X-Patchwork-Id: 10910441 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4166513B5 for ; Sun, 21 Apr 2019 01:44:38 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 30D7A28950 for ; Sun, 21 Apr 2019 01:44:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2526728965; Sun, 21 Apr 2019 01:44:38 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.7 required=2.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id AB8B128950 for ; Sun, 21 Apr 2019 01:44:37 +0000 (UTC) Received: from [127.0.0.1] (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id A480221219AC8; Sat, 20 Apr 2019 18:44:37 -0700 (PDT) X-Original-To: linux-nvdimm@lists.01.org Delivered-To: linux-nvdimm@lists.01.org Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=2607:f8b0:4864:20::844; helo=mail-qt1-x844.google.com; envelope-from=pasha.tatashin@soleen.com; receiver=linux-nvdimm@lists.01.org Received: from mail-qt1-x844.google.com (mail-qt1-x844.google.com [IPv6:2607:f8b0:4864:20::844]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 77135211F9D74 for ; Sat, 20 Apr 2019 18:44:36 -0700 (PDT) Received: by mail-qt1-x844.google.com with SMTP id w5so8938697qtb.11 for ; Sat, 20 Apr 2019 18:44:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=soleen.com; s=google; h=from:to:subject:date:message-id:in-reply-to:references:mime-version :content-transfer-encoding; bh=KL328kJp7uYop/CaXZcmGRKfoBkXK0v1G+nukTp5itg=; b=ZcOj6/tWBZki8VSTYWIx2hC0zATUWkFU1OTXUPmLys73YN2QUPVmWMkCAzisCIphb4 lagFcRl0UAa1+nKpZPFW6/ywAODOoC2ElJuMxdMZK+n/MVj6NLUv0dZbEJuUtuqfRbAG 2vQO7zgIlXc6foQWwNvVaXJ4cmOF6Nv1Mbrym5SdV+qbCVa1vCnbCbAIPeojIxSuiyzv alULIAAU7iGCTj9LS/VnbEzAzTbYgUAZW4UQycLNdEUtMMs7BATfDuCFjGJGPJtHwATa X1SGiIiiccfzYurY/yFrS0TMcM5+2hTPgZVtuHjsxwv960+2M26QfeQOg2ZSfR+OrX9P Nihw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=KL328kJp7uYop/CaXZcmGRKfoBkXK0v1G+nukTp5itg=; b=LW2+5pJXYSNgOBOwjv9V6NfxRHG8RgHUkviW7tuc1mPE3DQhttUJm0zKXPUkcJZfmr G01lVudTS2cTdErwjJkeuRF5jHXGw48ik/CzP9qK6L3EEyMvlq5KZptDnFe2J5UlkkEs t+RRnBIEuUAXQyv3Q1KBCxI8ru4KKhcdHI9C7xjAbzRx4WqTXtjE5PvNhGbpKjDFkRd5 I2fhxxE6lm0Z/duPkI4iO6mlDHvNqA3XWtwhAA57dQHi49qjhiDZkIPpC45jtj7GIzvA 6mTWC5bnZKHPcHCr/+moJ4G8oIf5pRhwo/5xS9L2b4w0QK52A91Dxzl6S+gBkW95s07G QvBQ== X-Gm-Message-State: APjAAAXvZ1QEIR68pH2i9b4darh+4Ev6QTgXhQib0PHd+/MNMabanCSW x9YRpgGukGB2X/r3K4GeABtpYA== X-Google-Smtp-Source: APXvYqwLrbFXWXl4ushQLhaJbuTDu4grdgvxRuAMcypo1JTsKGB8Q7Xxy+bv6W6dd9hWBd51O4WhFg== X-Received: by 2002:ac8:1776:: with SMTP id u51mr436168qtk.151.1555811075671; Sat, 20 Apr 2019 18:44:35 -0700 (PDT) Received: from localhost.localdomain (c-73-69-118-222.hsd1.nh.comcast.net. [73.69.118.222]) by smtp.gmail.com with ESMTPSA id u1sm1385218qtj.50.2019.04.20.18.44.34 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 20 Apr 2019 18:44:34 -0700 (PDT) From: Pavel Tatashin To: pasha.tatashin@soleen.com, jmorris@namei.org, sashal@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-nvdimm@lists.01.org, akpm@linux-foundation.org, mhocko@suse.com, dave.hansen@linux.intel.com, dan.j.williams@intel.com, keith.busch@intel.com, vishal.l.verma@intel.com, dave.jiang@intel.com, zwisler@kernel.org, thomas.lendacky@amd.com, ying.huang@intel.com, fengguang.wu@intel.com, bp@suse.de, bhelgaas@google.com, baiyaowei@cmss.chinamobile.com, tiwai@suse.de, jglisse@redhat.com Subject: [v2 2/2] device-dax: "Hotremove" persistent memory that is used like normal RAM Date: Sat, 20 Apr 2019 21:44:29 -0400 Message-Id: <20190421014429.31206-3-pasha.tatashin@soleen.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190421014429.31206-1-pasha.tatashin@soleen.com> References: <20190421014429.31206-1-pasha.tatashin@soleen.com> MIME-Version: 1.0 X-BeenThere: linux-nvdimm@lists.01.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Linux-nvdimm developer list." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" X-Virus-Scanned: ClamAV using ClamSMTP It is now allowed to use persistent memory like a regular RAM, but currently there is no way to remove this memory until machine is rebooted. This work expands the functionality to also allows hotremoving previously hotplugged persistent memory, and recover the device for use for other purposes. To hotremove persistent memory, the management software must first offline all memory blocks of dax region, and than unbind it from device-dax/kmem driver. So, operations should look like this: echo offline > echo offline > /sys/devices/system/memory/memoryN/state ... echo dax0.0 > /sys/bus/dax/drivers/kmem/unbind Note: if unbind is done without offlining memory beforehand, it won't be possible to do dax0.0 hotremove, and dax's memory is going to be part of System RAM until reboot. Signed-off-by: Pavel Tatashin --- drivers/dax/dax-private.h | 2 + drivers/dax/kmem.c | 91 +++++++++++++++++++++++++++++++++++++-- 2 files changed, 89 insertions(+), 4 deletions(-) diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h index a45612148ca0..999aaf3a29b3 100644 --- a/drivers/dax/dax-private.h +++ b/drivers/dax/dax-private.h @@ -53,6 +53,7 @@ struct dax_region { * @pgmap - pgmap for memmap setup / lifetime (driver owned) * @ref: pgmap reference count (driver owned) * @cmp: @ref final put completion (driver owned) + * @dax_mem_res: physical address range of hotadded DAX memory */ struct dev_dax { struct dax_region *region; @@ -62,6 +63,7 @@ struct dev_dax { struct dev_pagemap pgmap; struct percpu_ref ref; struct completion cmp; + struct resource *dax_kmem_res; }; static inline struct dev_dax *to_dev_dax(struct device *dev) diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c index 4c0131857133..d4896b281036 100644 --- a/drivers/dax/kmem.c +++ b/drivers/dax/kmem.c @@ -71,21 +71,104 @@ int dev_dax_kmem_probe(struct device *dev) kfree(new_res); return rc; } + dev_dax->dax_kmem_res = new_res; return 0; } +#ifdef CONFIG_MEMORY_HOTREMOVE +/* + * Check that device-dax's memory_blocks are offline. If a memory_block is not + * offline a warning is printed and an error is returned. dax hotremove can + * succeed only when every memory_block is offlined beforehand. + */ +static int +offline_memblock_cb(struct memory_block *mem, void *arg) +{ + struct device *mem_dev = &mem->dev; + bool is_offline; + + device_lock(mem_dev); + is_offline = mem_dev->offline; + device_unlock(mem_dev); + + if (!is_offline) { + struct device *dev = (struct device *)arg; + unsigned long spfn = section_nr_to_pfn(mem->start_section_nr); + unsigned long epfn = section_nr_to_pfn(mem->end_section_nr); + phys_addr_t spa = spfn << PAGE_SHIFT; + phys_addr_t epa = epfn << PAGE_SHIFT; + + dev_warn(dev, "memory block [%pa-%pa] is not offline\n", + &spa, &epa); + + return -EBUSY; + } + + return 0; +} + +static int dev_dax_kmem_remove(struct device *dev) +{ + struct dev_dax *dev_dax = to_dev_dax(dev); + struct resource *res = dev_dax->dax_kmem_res; + resource_size_t kmem_start; + resource_size_t kmem_size; + unsigned long start_pfn; + unsigned long end_pfn; + int rc; + + /* + * dax kmem resource does not exist, means memory was never hotplugged. + * So, nothing to do here. + */ + if (!res) + return 0; + + kmem_start = res->start; + kmem_size = resource_size(res); + start_pfn = kmem_start >> PAGE_SHIFT; + end_pfn = start_pfn + (kmem_size >> PAGE_SHIFT) - 1; + + /* + * Walk and check that every singe memory_block of dax region is + * offline + */ + lock_device_hotplug(); + rc = walk_memory_range(start_pfn, end_pfn, dev, offline_memblock_cb); + unlock_device_hotplug(); + + /* + * If admin has not offlined memory beforehand, we cannot hotremove dax. + * Unfortunately, because unbind will still succeed there is no way for + * user to hotremove dax after this. + */ + if (rc) + return rc; + + /* Hotremove memory, cannot fail because memory is already offlined */ + remove_memory(dev_dax->target_node, kmem_start, kmem_size); + + /* Release and free dax resources */ + release_resource(res); + kfree(res); + dev_dax->dax_kmem_res = NULL; + + return 0; +} +#else static int dev_dax_kmem_remove(struct device *dev) { /* - * Purposely leak the request_mem_region() for the device-dax - * range and return '0' to ->remove() attempts. The removal of - * the device from the driver always succeeds, but the region - * is permanently pinned as reserved by the unreleased + * Without hotremove purposely leak the request_mem_region() for the + * device-dax range and return '0' to ->remove() attempts. The removal + * of the device from the driver always succeeds, but the region is + * permanently pinned as reserved by the unreleased * request_mem_region(). */ return 0; } +#endif /* CONFIG_MEMORY_HOTREMOVE */ static struct dax_device_driver device_dax_kmem_driver = { .drv = {