libnvdimm: Use max contiguous area for namespace size

This patch will find the max contiguous area to determine the largest
pmem namespace size that can be created. If the requested size exceeds
the largest available, ENOSPC error will be returned.

This fixes the allocation underrun error and wrong error return code
that have otherwise been observed as the following kernel warning:

  WARNING: CPU: <CPU> PID: <PID> at drivers/nvdimm/namespace_devs.c:913 size_store

Fixes: a1f3e4d6a0c3 ("libnvdimm, region: update nd_region_available_dpa() for multi-pmem support")
Cc: <stable@vger.kernel.org>
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>

1 files changed, 3 insertions, 3 deletions

diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c
index cb322f2bc605..4a4266250c28 100644
--- a/drivers/nvdimm/namespace_devs.c
+++ b/drivers/nvdimm/namespace_devs.c
@@ -799,7 +799,7 @@ static int merge_dpa(struct nd_region *nd_region,
         return 0;
 }
 
-static int __reserve_free_pmem(struct device *dev, void *data)
+int __reserve_free_pmem(struct device *dev, void *data)
 {
         struct nvdimm *nvdimm = data;
         struct nd_region *nd_region;
@@ -836,7 +836,7 @@ static int __reserve_free_pmem(struct device *dev, void *data)
         return 0;
 }
 
-static void release_free_pmem(struct nvdimm_bus *nvdimm_bus,
+void release_free_pmem(struct nvdimm_bus *nvdimm_bus,
                 struct nd_mapping *nd_mapping)
 {
         struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
@@ -1032,7 +1032,7 @@ static ssize_t __size_store(struct device *dev, unsigned long long val)
 
                 allocated += nvdimm_allocated_dpa(ndd, &label_id);
         }
-        available = nd_region_available_dpa(nd_region);
+        available = nd_region_allocatable_dpa(nd_region);
 
         if (val > available + allocated)
                 return -ENOSPC;