[PATCH 4.9 109/151] mm/memory_hotplug: Do not unlock when fails to take the device_hotplug_lock

[Greg Kroah-Hartman]

From: zhong jiang <zhongjiang@xxxxxxxxxx>

[ Upstream commit d2ab99403ee00d8014e651728a4702ea1ae5e52c ]

When adding the memory by probing memory block in sysfs interface, there is an
obvious issue that we will unlock the device_hotplug_lock when fails to takes it.

That issue was introduced in Commit 8df1d0e4a265
("mm/memory_hotplug: make add_memory() take the device_hotplug_lock")

We should drop out in time when fails to take the device_hotplug_lock.

Fixes: 8df1d0e4a265 ("mm/memory_hotplug: make add_memory() take the device_hotplug_lock")
Reported-by: Yang yingliang <yangyingliang@xxxxxxxxxx>
Signed-off-by: zhong jiang <zhongjiang@xxxxxxxxxx>
Reviewed-by: Oscar Salvador <osalvador@xxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/base/memory.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 9f96f1b43c15f..6a3694a4843f8 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -502,7 +502,7 @@ memory_probe_store(struct device *dev, struct device_attribute *attr,
 
 	ret = lock_device_hotplug_sysfs();
 	if (ret)
-		goto out;
+		return ret;
 
 	nid = memory_add_physaddr_to_nid(phys_addr);
 	ret = __add_memory(nid, phys_addr,
-- 
2.20.1