@@ -433,6 +433,21 @@ static ssize_t available_size_show(struct device *dev,
}
static DEVICE_ATTR_RO(available_size);
+static ssize_t max_available_extent_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct nd_region *nd_region = to_nd_region(dev);
+ unsigned long long available = 0;
+
+ nvdimm_bus_lock(dev);
+ wait_nvdimm_bus_probe_idle(dev);
+ available = nd_region_contiguous_max(nd_region);
+ nvdimm_bus_unlock(dev);
+
+ return sprintf(buf, "%llu\n", available);
+}
+static DEVICE_ATTR_RO(max_available_extent);
+
static ssize_t init_namespaces_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -584,6 +599,7 @@ static struct attribute *nd_region_attributes[] = {
&dev_attr_read_only.attr,
&dev_attr_set_cookie.attr,
&dev_attr_available_size.attr,
+ &dev_attr_max_available_extent.attr,
&dev_attr_namespace_seed.attr,
&dev_attr_init_namespaces.attr,
&dev_attr_badblocks.attr,
The 'available_size' attribute showing the combined total of all unallocated space isn't always useful to know how large of a namespace a user may be able to allocate if the region is fragmented. This patch will export the largest extent of contiguous unallocated space that may be allocated to create a new namespace. Signed-off-by: Keith Busch <keith.busch@intel.com> --- drivers/nvdimm/region_devs.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)