There is a small window whereby ARS scan requests can schedule work that
userspace will miss when polling scrub_show. Hold the init_mutex lock
over calls to report the status to close this potential escape. Also,
make sure that requests to cancel the ARS workqueue are treated as an
idle event.
Cc: <stable@xxxxxxxxxxxxxxx>
Cc: Vishal Verma <vishal.l.verma@xxxxxxxxx>
Fixes: 37b137ff8c83 ("nfit, libnvdimm: allow an ARS scrub...")
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/acpi/nfit/core.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index ea9f3e727fef..2a1fc3817a81 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -1249,8 +1249,11 @@ static ssize_t scrub_show(struct device *dev,
if (nd_desc) {
struct acpi_nfit_desc *acpi_desc = to_acpi_desc(nd_desc);
+ mutex_lock(&acpi_desc->init_mutex);
rc = sprintf(buf, "%d%s", acpi_desc->scrub_count,
- (work_busy(&acpi_desc->work)) ? "+\n" : "\n");
+ work_busy(&acpi_desc->work)
+ && !acpi_desc->cancel ? "+\n" : "\n");
+ mutex_unlock(&acpi_desc->init_mutex);
}
device_unlock(dev);
return rc;