[PATCH v3] memory-hotplug: fix store_mem_state() return value

[Reza Arbab]

If store_mem_state() is called to online memory which is already online,
it will return 1, the value it got from device_online().

This is wrong because store_mem_state() is a device_attribute .store
function. Thus a non-negative return value represents input bytes read.

Set the return value to -EINVAL in this case.

Signed-off-by: Reza Arbab <arbab@xxxxxxxxxxxxxxxxxx>
---
v2 -> v3:
* David Rientjes pointed out that the backwards-compatible return 
  value in this situation is -EINVAL, not success. I had mistakenly
  thought the behavior should be the same as online_store().

 drivers/base/memory.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 1cea0ba..bb69e58 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -359,8 +359,11 @@ store_mem_state(struct device *dev,
 err:
 	unlock_device_hotplug();
 
-	if (ret)
+	if (ret < 0)
 		return ret;
+	if (ret)
+		return -EINVAL;
+
 	return count;
 }
 
-- 
1.8.3.1