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@xxxxxxxxx>
---
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 {
--
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