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nfit: disable userspace initiated ars during scrub

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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 <dan.j.williams@intel.com>
This commit is contained in:
Dan Williams 2016-02-22 21:50:31 -08:00
parent 1cf03c00e7
commit 87bf572e19
3 changed files with 38 additions and 5 deletions
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23
drivers/acpi/nfit.c
View file

@ -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);

18
drivers/nvdimm/bus.c
View file

@ -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;

2
include/linux/libnvdimm.h
View file

@ -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 {