memory-hotplug: fix store_mem_state() return value

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.

Link: http://lkml.kernel.org/r/1472743777-24266-1-git-send-email-arbab@linux.vnet.ibm.com
Signed-off-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Chen Yucong <slaoub@gmail.com>
Cc: Andrew Banman <abanman@sgi.com>
Cc: Seth Jennings <sjenning@redhat.com>
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 dc75de9059cd1983401b35bffb5c697d2e55b813..62c63c0c5c22dcfee3e2d706e68be053519cc40c 100644 (file)
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -361,8 +361,11 @@ store_mem_state(struct device *dev,
 err:
        unlock_device_hotplug();
 
-       if (ret)
+       if (ret < 0)
                return ret;
+       if (ret)
+               return -EINVAL;
+
        return count;
 }