From patchwork Wed Mar 10 01:43:38 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 12126805 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7BDD6C433E6 for ; Wed, 10 Mar 2021 01:44:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4B603650FD for ; Wed, 10 Mar 2021 01:44:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231382AbhCJBnp (ORCPT ); Tue, 9 Mar 2021 20:43:45 -0500 Received: from mga11.intel.com ([192.55.52.93]:20658 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231422AbhCJBnm (ORCPT ); Tue, 9 Mar 2021 20:43:42 -0500 IronPort-SDR: JZTopoaVIAtciT6GBg6LMHiGyQCBhkM354fHXBs8ZoxscnF3O47DCdloFlpDIcNBt+n2s6Tnwm YRRO+SwcBx4w== X-IronPort-AV: E=McAfee;i="6000,8403,9917"; a="185004425" X-IronPort-AV: E=Sophos;i="5.81,236,1610438400"; d="scan'208";a="185004425" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Mar 2021 17:43:39 -0800 IronPort-SDR: Y7+W9Tom12E92Bku2I5dnJLtcYucyCcPGg1e9R0eUmX++VmOvYAoe74ImkoAF04m6TxXJHyD+q JzwsFQh5Lx0Q== X-IronPort-AV: E=Sophos;i="5.81,236,1610438400"; d="scan'208";a="409973299" Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.25]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Mar 2021 17:43:38 -0800 Subject: [PATCH v2] libnvdimm: Notify disk drivers to revalidate region read-only From: Dan Williams To: linux-nvdimm@lists.01.org Cc: Christoph Hellwig , Ming Lei , "Martin K. Petersen" , Hannes Reinecke , Jens Axboe , kernel test robot , Vishal Verma , linux-kernel@vger.kernel.org, linux-block@vger.kernel.org Date: Tue, 09 Mar 2021 17:43:38 -0800 Message-ID: <161534060720.528671.2341213328968989192.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.18-3-g996c MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Previous kernels allowed the BLKROSET to override the disk's read-only status. With that situation fixed the pmem driver needs to rely on notification events to reevaluate the disk read-only status after the host region has been marked read-write. Recall that when libnvdimm determines that the persistent memory has lost persistence (for example lack of energy to flush from DRAM to FLASH on an NVDIMM-N device) it marks the region read-only, but that state can be overridden by the user via: echo 0 > /sys/bus/nd/devices/regionX/read_only ...to date there is no notification that the region has restored persistence, so the user override is the only recovery. Fixes: 52f019d43c22 ("block: add a hard-readonly flag to struct gendisk") Cc: Christoph Hellwig Cc: Ming Lei Cc: Martin K. Petersen Cc: Hannes Reinecke Cc: Jens Axboe Reported-by: kernel test robot Reported-by: Vishal Verma Signed-off-by: Dan Williams Reviewed-by: Christoph Hellwig Tested-by: Vishal Verma --- Changes since v1 [1]: - Move from the sinking ship of revalidate_disk() to the local hotness of nd_pmem_notify() (hch). [1]: http://lore.kernel.org/r/161527286194.446794.5215036039655765042.stgit@dwillia2-desk3.amr.corp.intel.com drivers/nvdimm/bus.c | 14 ++++++-------- drivers/nvdimm/pmem.c | 37 +++++++++++++++++++++++++++++++++---- drivers/nvdimm/region_devs.c | 7 +++++++ include/linux/nd.h | 1 + 4 files changed, 47 insertions(+), 12 deletions(-) diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c index 48f0985ca8a0..3a777d0073b7 100644 --- a/drivers/nvdimm/bus.c +++ b/drivers/nvdimm/bus.c @@ -631,16 +631,14 @@ void nvdimm_check_and_set_ro(struct gendisk *disk) struct nd_region *nd_region = to_nd_region(dev->parent); int disk_ro = get_disk_ro(disk); - /* - * Upgrade to read-only if the region is read-only preserve as - * read-only if the disk is already read-only. - */ - if (disk_ro || nd_region->ro == disk_ro) + /* catch the disk up with the region ro state */ + if (disk_ro == nd_region->ro) return; - dev_info(dev, "%s read-only, marking %s read-only\n", - dev_name(&nd_region->dev), disk->disk_name); - set_disk_ro(disk, 1); + dev_info(dev, "%s read-%s, marking %s read-%s\n", + dev_name(&nd_region->dev), nd_region->ro ? "only" : "write", + disk->disk_name, nd_region->ro ? "only" : "write"); + set_disk_ro(disk, nd_region->ro); } EXPORT_SYMBOL(nvdimm_check_and_set_ro); diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index b8a85bfb2e95..7daac795db39 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -26,6 +26,7 @@ #include #include #include "pmem.h" +#include "btt.h" #include "pfn.h" #include "nd.h" @@ -585,7 +586,7 @@ static void nd_pmem_shutdown(struct device *dev) nvdimm_flush(to_nd_region(dev->parent), NULL); } -static void nd_pmem_notify(struct device *dev, enum nvdimm_event event) +static void pmem_revalidate_poison(struct device *dev) { struct nd_region *nd_region; resource_size_t offset = 0, end_trunc = 0; @@ -595,9 +596,6 @@ static void nd_pmem_notify(struct device *dev, enum nvdimm_event event) struct range range; struct kernfs_node *bb_state; - if (event != NVDIMM_REVALIDATE_POISON) - return; - if (is_nd_btt(dev)) { struct nd_btt *nd_btt = to_nd_btt(dev); @@ -635,6 +633,37 @@ static void nd_pmem_notify(struct device *dev, enum nvdimm_event event) sysfs_notify_dirent(bb_state); } +static void pmem_revalidate_region(struct device *dev) +{ + struct pmem_device *pmem; + + if (is_nd_btt(dev)) { + struct nd_btt *nd_btt = to_nd_btt(dev); + struct btt *btt = nd_btt->btt; + + nvdimm_check_and_set_ro(btt->btt_disk); + return; + } + + pmem = dev_get_drvdata(dev); + nvdimm_check_and_set_ro(pmem->disk); +} + +static void nd_pmem_notify(struct device *dev, enum nvdimm_event event) +{ + switch (event) { + case NVDIMM_REVALIDATE_POISON: + pmem_revalidate_poison(dev); + break; + case NVDIMM_REVALIDATE_REGION: + pmem_revalidate_region(dev); + break; + default: + dev_WARN_ONCE(dev, 1, "notify: unknown event: %d\n", event); + break; + } +} + MODULE_ALIAS("pmem"); MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_IO); MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_PMEM); diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c index ef23119db574..51870eb51da6 100644 --- a/drivers/nvdimm/region_devs.c +++ b/drivers/nvdimm/region_devs.c @@ -518,6 +518,12 @@ static ssize_t read_only_show(struct device *dev, return sprintf(buf, "%d\n", nd_region->ro); } +static int revalidate_read_only(struct device *dev, void *data) +{ + nd_device_notify(dev, NVDIMM_REVALIDATE_REGION); + return 0; +} + static ssize_t read_only_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { @@ -529,6 +535,7 @@ static ssize_t read_only_store(struct device *dev, return rc; nd_region->ro = ro; + device_for_each_child(dev, NULL, revalidate_read_only); return len; } static DEVICE_ATTR_RW(read_only); diff --git a/include/linux/nd.h b/include/linux/nd.h index cec526c8043d..ee9ad76afbba 100644 --- a/include/linux/nd.h +++ b/include/linux/nd.h @@ -11,6 +11,7 @@ enum nvdimm_event { NVDIMM_REVALIDATE_POISON, + NVDIMM_REVALIDATE_REGION, }; enum nvdimm_claim_class {