mm/memory_hotplug: do not unlock after failing to take the device_hotplug_lock

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 6c615b6bae48 ("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@huawei.com
Fixes: 6c615b6bae48 ("mm/memory_hotplug: make add_memory() take the device_hotplug_lock")
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Reported-by: Yang yingliang <yangyingliang@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index cb8347500ce2871e5003d8ce45a4014a97b8de3e..e49028a604295937a59761488d431b9f4837f731 100644 (file)
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -506,7 +506,7 @@ static ssize_t 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,