[PATCH 5.0 112/115] mm/memory_hotplug: do not unlock after failing to take the device_hotplug_lock

[Greg Kroah-Hartman]

From: zhong jiang <zhongjiang@xxxxxxxxxx>

commit 37803841c92d7b327147e0b1be3436423189e1cf upstream.

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

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

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

Link: http://lkml.kernel.org/r/1554696437-9593-1-git-send-email-zhongjiang@xxxxxxxxxx
Fixes: 8df1d0e4a265 ("mm/memory_hotplug: make add_memory() take the device_hotplug_lock")
Signed-off-by: zhong jiang <zhongjiang@xxxxxxxxxx>
Reported-by: Yang yingliang <yangyingliang@xxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Reviewed-by: Oscar Salvador <osalvador@xxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/base/memory.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -505,7 +505,7 @@ static ssize_t probe_store(struct device
 
 	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,