libnvdimm: allow legacy (e820) pmem region to clear bad blocks

Bad blocks can be injected via /sys/block/pmemN/badblocks. In a situation
where legacy pmem is being used or a pmem region created by using memmap
kernel parameter, the injected bad blocks are not cleared due to
nvdimm_clear_poison() failing from lack of ndctl function pointer. In
this case we need to just return as handled and allow the bad blocks to
be cleared rather than fail.

Reviewed-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
index 458daf927336..935866fe5ec2 100644
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -185,8 +185,12 @@ long nvdimm_clear_poison(struct device *dev, phys_addr_t phys,
                 return -ENXIO;
 
         nd_desc = nvdimm_bus->nd_desc;
+        /*
+         * if ndctl does not exist, it's PMEM_LEGACY and
+         * we want to just pretend everything is handled.
+         */
         if (!nd_desc->ndctl)
-                return -ENXIO;
+                return len;
 
         memset(&ars_cap, 0, sizeof(ars_cap));
         ars_cap.address = phys;