Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm fixes from Dan Williams:

 - Fix for the nd_blk (NVDIMM Block Window Aperture) driver.

   A spec clarification requires the driver to mask off reserved bits in
   status register.  This is tagged for -stable back to the v4.2 kernel.

 - Fix for a kernel crash in the nvdimm unit tests when module loading
   is interrupted with SIGTERM.  Tagged for -stable since validation
   efforts external to Intel use the unit tests for qualifying
   backports.

 - Add a new 'size' sysfs attribute for the BTT (NVDIMM Block
   Translation Table) driver to make it symmetric with the other
   namespace personality drivers (PFN and DAX) that provide a size
   attribute for indicating how much namespace capacity is lost to
   metadata.

   The BTT change arrived at the start of the merge window and has
   appeared in a -next release.  It can technically wait for 4.9, but it
   is small, fixes asymmetry in the libnvdimm-sysfs interface, and
   something I would have squeezed into the v4.8 pull request had it
   arrived a few days earlier.

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  tools/testing/nvdimm: fix SIGTERM vs hotplug crash
  nvdimm, btt: add a size attribute for BTTs
  libnvdimm, nd_blk: mask off reserved status bits

1 files changed, 20 insertions, 0 deletions

diff --git a/drivers/nvdimm/btt_devs.c b/drivers/nvdimm/btt_devs.c
index 3fa7919f94a8..97dd2925ed6e 100644
--- a/drivers/nvdimm/btt_devs.c
+++ b/drivers/nvdimm/btt_devs.c
@@ -140,10 +140,30 @@ static ssize_t namespace_store(struct device *dev,
 }
 static DEVICE_ATTR_RW(namespace);
 
+static ssize_t size_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct nd_btt *nd_btt = to_nd_btt(dev);
+	ssize_t rc;
+
+	device_lock(dev);
+	if (dev->driver)
+		rc = sprintf(buf, "%llu\n", nd_btt->size);
+	else {
+		/* no size to convey if the btt instance is disabled */
+		rc = -ENXIO;
+	}
+	device_unlock(dev);
+
+	return rc;
+}
+static DEVICE_ATTR_RO(size);
+
 static struct attribute *nd_btt_attributes[] = {
 	&dev_attr_sector_size.attr,
 	&dev_attr_namespace.attr,
 	&dev_attr_uuid.attr,
+	&dev_attr_size.attr,
 	NULL,
 };