libnvdimm: Export max available extent

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 unallocated space that may be allocated
to create a new namespace.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
This commit is contained in:
Keith Busch 2018-07-24 15:07:58 -06:00 committed by Dave Jiang
parent 12e3129e29
commit 1e687220ef
1 changed files with 16 additions and 0 deletions

View File

@ -434,6 +434,21 @@ 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_allocatable_dpa(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)
{
@ -585,6 +600,7 @@ 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,