Commit 78727137 authored Apr 02, 2018 by Dan Williams

nfit, address-range-scrub: fix scrub in-progress reporting

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@vger.kernel.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Fixes: 37b137ff ("nfit, libnvdimm: allow an ARS scrub...")
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

parent 8d0d8ed3

drivers/acpi/nfit/core.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -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;