From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755493AbcBXCSG (ORCPT ); Tue, 23 Feb 2016 21:18:06 -0500 Received: from mga11.intel.com ([192.55.52.93]:8315 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751830AbcBXCR7 (ORCPT ); Tue, 23 Feb 2016 21:17:59 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.22,492,1449561600"; d="scan'208";a="658236357" Subject: [PATCH 7/8] nfit: disable userspace initiated ars during scrub From: Dan Williams To: linux-nvdimm@ml01.01.org Cc: linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org Date: Tue, 23 Feb 2016 18:17:35 -0800 Message-ID: <20160224021735.22776.23957.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <20160224021655.22776.87952.stgit@dwillia2-desk3.amr.corp.intel.com> References: <20160224021655.22776.87952.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.17.1-9-g687f MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org While the nfit driver is issuing address range scrub commands and reaping the results do not permit an ars_start command issued from userspace. The scrub thread assumes that all ars completions are for scrubs initiated by platform firmware at boot, or by the nfit driver. Signed-off-by: Dan Williams --- drivers/acpi/nfit.c | 23 +++++++++++++++++++++++ drivers/nvdimm/bus.c | 18 +++++++++++++----- include/linux/libnvdimm.h | 2 ++ 3 files changed, 38 insertions(+), 5 deletions(-) diff --git a/drivers/acpi/nfit.c b/drivers/acpi/nfit.c index 8e6a82e7a87f..2be263e1dc92 100644 --- a/drivers/acpi/nfit.c +++ b/drivers/acpi/nfit.c @@ -2186,6 +2186,28 @@ static int acpi_nfit_flush_probe(struct nvdimm_bus_descriptor *nd_desc) return wait_for_completion_interruptible(&flush.cmp); } +static int acpi_nfit_clear_to_send(struct nvdimm_bus_descriptor *nd_desc, + struct nvdimm *nvdimm, unsigned int cmd) +{ + struct acpi_nfit_desc *acpi_desc = to_acpi_nfit_desc(nd_desc); + + if (nvdimm) + return 0; + if (cmd != ND_CMD_ARS_START) + return 0; + + /* + * The kernel and userspace may race to initiate a scrub, but + * the scrub thread is prepared to lose that initial race. It + * just needs guarantees that any ars it initiates are not + * interrupted by any intervening start reqeusts from userspace. + */ + if (work_busy(&acpi_desc->work)) + return -EBUSY; + + return 0; +} + void acpi_nfit_desc_init(struct acpi_nfit_desc *acpi_desc, struct device *dev) { struct nvdimm_bus_descriptor *nd_desc; @@ -2197,6 +2219,7 @@ void acpi_nfit_desc_init(struct acpi_nfit_desc *acpi_desc, struct device *dev) nd_desc->provider_name = "ACPI.NFIT"; nd_desc->ndctl = acpi_nfit_ctl; nd_desc->flush_probe = acpi_nfit_flush_probe; + nd_desc->clear_to_send = acpi_nfit_clear_to_send; nd_desc->attr_groups = acpi_nfit_attribute_groups; INIT_LIST_HEAD(&acpi_desc->spa_maps); diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c index 2508251439e7..228c0e9f430e 100644 --- a/drivers/nvdimm/bus.c +++ b/drivers/nvdimm/bus.c @@ -490,16 +490,24 @@ void wait_nvdimm_bus_probe_idle(struct device *dev) } /* set_config requires an idle interleave set */ -static int nd_cmd_clear_to_send(struct nvdimm *nvdimm, unsigned int cmd) +static int nd_cmd_clear_to_send(struct nvdimm_bus *nvdimm_bus, + struct nvdimm *nvdimm, unsigned int cmd) { - struct nvdimm_bus *nvdimm_bus; + struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc; + + /* ask the bus provider if it would like to block this request */ + if (nd_desc->clear_to_send) { + int rc = nd_desc->clear_to_send(nd_desc, nvdimm, cmd); + + if (rc) + return rc; + } if (!nvdimm || cmd != ND_CMD_SET_CONFIG_DATA) return 0; - nvdimm_bus = walk_to_nvdimm_bus(&nvdimm->dev); + /* prevent label manipulation while the kernel owns label updates */ wait_nvdimm_bus_probe_idle(&nvdimm_bus->dev); - if (atomic_read(&nvdimm->busy)) return -EBUSY; return 0; @@ -609,7 +617,7 @@ static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm, } nvdimm_bus_lock(&nvdimm_bus->dev); - rc = nd_cmd_clear_to_send(nvdimm, cmd); + rc = nd_cmd_clear_to_send(nvdimm_bus, nvdimm, cmd); if (rc) goto out_unlock; diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h index 2299f8742f7f..833867b9ddc2 100644 --- a/include/linux/libnvdimm.h +++ b/include/linux/libnvdimm.h @@ -72,6 +72,8 @@ struct nvdimm_bus_descriptor { char *provider_name; ndctl_fn ndctl; int (*flush_probe)(struct nvdimm_bus_descriptor *nd_desc); + int (*clear_to_send)(struct nvdimm_bus_descriptor *nd_desc, + struct nvdimm *nvdimm, unsigned int cmd); }; struct nd_cmd_desc {