[PATCH 4.14 131/222] libnvdimm: Hold reference on parent while scheduling async init

Greg Kroah-Hartman
2018-11-11T22:32:50Z

From: Alexander Duyck <alexander.h.duyck@linux.intel.com>

commit b6eae0f61db27748606cc00dafcfd1e2c032f0a5 upstream.

Unlike asynchronous initialization in the core we have not yet associated
the device with the parent, and as such the device doesn't hold a reference
to the parent.

In order to resolve that we should be holding a reference on the parent
until the asynchronous initialization has completed.

Cc: <stable@vger.kernel.org>
Fixes: 4d88a97aa9e8 ("libnvdimm: ...base ... infrastructure")
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/nvdimm/bus.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -484,6 +484,8 @@ static void nd_async_device_register(voi
put_device(dev);
}
put_device(dev);
+ if (dev->parent)
+ put_device(dev->parent);
}

static void nd_async_device_unregister(void *d, async_cookie_t cookie)
@@ -503,6 +505,8 @@ void __nd_device_register(struct device
if (!dev)
return;
dev->bus = &nvdimm_bus_type;
+ if (dev->parent)
+ get_device(dev->parent);
get_device(dev);
async_schedule_domain(nd_async_device_register, dev,
&nd_async_domain);