libnvdimm/pmem: Advance namespace seed for specific probe errors

In order to support marking namespaces with unsupported feature/versions
disabled, nvdimm core should advance the namespace seed on these
probe failures. Otherwise, these failed namespaces will be considered a
seed namespace and will be wrongly used while creating new namespaces.

Add -EOPNOTSUPP as return from pmem probe callback to indicate a namespace
initialization failures due to pfn superblock feature/version mismatch.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Link: https://lore.kernel.org/r/20190905154603.10349-3-aneesh.kumar@linux.ibm.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

2 files changed, 27 insertions, 5 deletions

diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
index ee6de34ae525..75a58a6e9615 100644
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -95,7 +95,8 @@ static int nvdimm_bus_probe(struct device *dev)
         rc = nd_drv->probe(dev);
         debug_nvdimm_unlock(dev);
 
-        if (rc == 0 && dev->parent && is_nd_region(dev->parent))
+        if ((rc == 0 || rc == -EOPNOTSUPP) &&
+                        dev->parent && is_nd_region(dev->parent))
                 nd_region_advance_seeds(to_nd_region(dev->parent), dev);
         nvdimm_bus_probe_end(nvdimm_bus);
 
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 4c121dd03dd9..f9f76f6ba07b 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -490,6 +490,7 @@ static int pmem_attach_disk(struct device *dev,
 
 static int nd_pmem_probe(struct device *dev)
 {
+        int ret;
         struct nd_namespace_common *ndns;
 
         ndns = nvdimm_namespace_common_probe(dev);
@@ -505,12 +506,32 @@ static int nd_pmem_probe(struct device *dev)
         if (is_nd_pfn(dev))
                 return pmem_attach_disk(dev, ndns);
 
-        /* if we find a valid info-block we'll come back as that personality */
-        if (nd_btt_probe(dev, ndns) == 0 || nd_pfn_probe(dev, ndns) == 0
-                        || nd_dax_probe(dev, ndns) == 0)
+        ret = nd_btt_probe(dev, ndns);
+        if (ret == 0)
                 return -ENXIO;
 
-        /* ...otherwise we're just a raw pmem device */
+        /*
+         * We have two failure conditions here, there is no
+         * info reserver block or we found a valid info reserve block
+         * but failed to initialize the pfn superblock.
+         *
+         * For the first case consider namespace as a raw pmem namespace
+         * and attach a disk.
+         *
+         * For the latter, consider this a success and advance the namespace
+         * seed.
+         */
+        ret = nd_pfn_probe(dev, ndns);
+        if (ret == 0)
+                return -ENXIO;
+        else if (ret == -EOPNOTSUPP)
+                return ret;
+
+        ret = nd_dax_probe(dev, ndns);
+        if (ret == 0)
+                return -ENXIO;
+        else if (ret == -EOPNOTSUPP)
+                return ret;
         return pmem_attach_disk(dev, ndns);
 }