[PATCH] cpu-hotplug: release `workqueue_mutex' properly on CPU hot-remove

_cpu_down() acquires `workqueue_mutex' on its process, but doen't release it
if __cpu_disable() fails.

Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 6 insertions, 6 deletions

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 27dd3ee47099..663c920b2234 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -150,18 +150,18 @@ static int _cpu_down(unsigned int cpu)
         p = __stop_machine_run(take_cpu_down, NULL, cpu);
         mutex_unlock(&cpu_bitmask_lock);
 
-        if (IS_ERR(p)) {
+        if (IS_ERR(p) || cpu_online(cpu)) {
                 /* CPU didn't die: tell everyone.  Can't complain. */
                 if (raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED,
                                 (void *)(long)cpu) == NOTIFY_BAD)
                         BUG();
 
-                err = PTR_ERR(p);
-                goto out_allowed;
-        }
-
-        if (cpu_online(cpu))
+                if (IS_ERR(p)) {
+                        err = PTR_ERR(p);
+                        goto out_allowed;
+                }
                 goto out_thread;
+        }
 
         /* Wait for it to sleep (leaving idle task). */
         while (!idle_cpu(cpu))