[PATCH v6 2/7] libnvdimm/pmem: Advance namespace seed for specific probe errors

Aneesh Kumar K.V
2019-08-19T13:36:33Z

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>
---
drivers/nvdimm/bus.c | 3 ++-
drivers/nvdimm/pmem.c | 29 +++++++++++++++++++++++++----
2 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
index 9b64e68a20b8..69f784bf9744 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);
}