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Commit 87bf572e authored by Dan Williams's avatar Dan Williams
Browse files

nfit: disable userspace initiated ars during scrub 



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: default avatarDan Williams <dan.j.williams@intel.com>
parent 1cf03c00

drivers/acpi/nfit.c

+23 −0
Original line number Original line Diff line number Diff line
@@ -2186,6 +2186,28 @@ static int acpi_nfit_flush_probe(struct nvdimm_bus_descriptor *nd_desc) 
	return wait_for_completion_interruptible(&flush.cmp);

	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)

void acpi_nfit_desc_init(struct acpi_nfit_desc *acpi_desc, struct device *dev)

{

{

	struct nvdimm_bus_descriptor *nd_desc;

	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->provider_name = "ACPI.NFIT";

	nd_desc->ndctl = acpi_nfit_ctl;

	nd_desc->ndctl = acpi_nfit_ctl;

	nd_desc->flush_probe = acpi_nfit_flush_probe;

	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;

	nd_desc->attr_groups = acpi_nfit_attribute_groups;





	INIT_LIST_HEAD(&acpi_desc->spa_maps);

	INIT_LIST_HEAD(&acpi_desc->spa_maps);

drivers/nvdimm/bus.c

+13 −5
Original line number Original line Diff line number Diff line
@@ -490,16 +490,24 @@ void wait_nvdimm_bus_probe_idle(struct device *dev) 
}

}





/* set_config requires an idle interleave set */

/* 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)

	if (!nvdimm || cmd != ND_CMD_SET_CONFIG_DATA)

		return 0;

		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);

	wait_nvdimm_bus_probe_idle(&nvdimm_bus->dev);



	if (atomic_read(&nvdimm->busy))

	if (atomic_read(&nvdimm->busy))

		return -EBUSY;

		return -EBUSY;

	return 0;

	return 0;
@@ -609,7 +617,7 @@ static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm, 
	}

	}





	nvdimm_bus_lock(&nvdimm_bus->dev);

	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)

	if (rc)

		goto out_unlock;

		goto out_unlock;

include/linux/libnvdimm.h

+2 −0
Original line number Original line Diff line number Diff line
@@ -72,6 +72,8 @@ struct nvdimm_bus_descriptor { 
	char *provider_name;

	char *provider_name;

	ndctl_fn ndctl;

	ndctl_fn ndctl;

	int (*flush_probe)(struct nvdimm_bus_descriptor *nd_desc);

	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 {

struct nd_cmd_desc {