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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, zhong jiang <zhongjiang@huawei.com>,
        Yang yingliang <yangyingliang@huawei.com>,
        Michal Hocko <mhocko@suse.com>,
        David Hildenbrand <david@redhat.com>,
        Oscar Salvador <osalvador@suse.de>,
        Andrew Morton <akpm@linux-foundation.org>,
        Linus Torvalds <torvalds@linux-foundation.org>
Subject: [PATCH 5.0 112/115] mm/memory_hotplug: do not unlock after failing to take the device_hotplug_lock
Date:   Wed, 24 Apr 2019 19:10:48 +0200
Message-Id: <20190424170931.214760929@linuxfoundation.org>
In-Reply-To: <20190424170924.797924502@linuxfoundation.org>
References: <20190424170924.797924502@linuxfoundation.org>
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From: zhong jiang <zhongjiang@huawei.com>

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@huawei.com
Fixes: 8df1d0e4a265 ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 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,