libnvdimm: stop requiring a driver ->remove() method

The dax_pmem driver was implementing an empty ->remove() method to
satisfy the nvdimm bus driver that unconditionally calls ->remove().
Teach the core bus driver to check if ->remove() is NULL to remove that
requirement.

Reported-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 5 insertions, 4 deletions

diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
index 97589e3cb852..7cbc3d58d176 100644
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -124,9 +124,10 @@ static int nvdimm_bus_remove(struct device *dev)
         struct nd_device_driver *nd_drv = to_nd_device_driver(dev->driver);
         struct module *provider = to_bus_provider(dev);
         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
-        int rc;
+        int rc = 0;
 
-        rc = nd_drv->remove(dev);
+        if (nd_drv->remove)
+                rc = nd_drv->remove(dev);
         nd_region_disable(nvdimm_bus, dev);
 
         dev_dbg(&nvdimm_bus->dev, "%s.remove(%s) = %d\n", dev->driver->name,
@@ -296,8 +297,8 @@ int __nd_driver_register(struct nd_device_driver *nd_drv, struct module *owner,
                 return -EINVAL;
         }
 
-        if (!nd_drv->probe || !nd_drv->remove) {
-                pr_debug("->probe() and ->remove() must be specified\n");
+        if (!nd_drv->probe) {
+                pr_debug("%s ->probe() must be specified\n", mod_name);
                 return -EINVAL;
         }