1 files changed, 40 insertions, 5 deletions

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 5bfb213984b2..327d2deb4451 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -229,6 +229,16 @@ static inline void set_wq_data(struct work_struct *work,
         atomic_long_set(&work->data, new);
 }
 
+/*
+ * Clear WORK_STRUCT_PENDING and the workqueue on which it was queued.
+ */
+static inline void clear_wq_data(struct work_struct *work)
+{
+        unsigned long flags = *work_data_bits(work) &
+                                (1UL << WORK_STRUCT_STATIC);
+        atomic_long_set(&work->data, flags);
+}
+
 static inline
 struct cpu_workqueue_struct *get_wq_data(struct work_struct *work)
 {
@@ -671,7 +681,7 @@ static int __cancel_work_timer(struct work_struct *work,
                 wait_on_work(work);
         } while (unlikely(ret < 0));
 
-        work_clear_pending(work);
+        clear_wq_data(work);
         return ret;
 }
 
@@ -845,6 +855,30 @@ int schedule_on_each_cpu(work_func_t func)
         return 0;
 }
 
+/**
+ * flush_scheduled_work - ensure that any scheduled work has run to completion.
+ *
+ * Forces execution of the kernel-global workqueue and blocks until its
+ * completion.
+ *
+ * Think twice before calling this function!  It's very easy to get into
+ * trouble if you don't take great care.  Either of the following situations
+ * will lead to deadlock:
+ *
+ *      One of the work items currently on the workqueue needs to acquire
+ *      a lock held by your code or its caller.
+ *
+ *      Your code is running in the context of a work routine.
+ *
+ * They will be detected by lockdep when they occur, but the first might not
+ * occur very often.  It depends on what work items are on the workqueue and
+ * what locks they need, which you have no control over.
+ *
+ * In most situations flushing the entire workqueue is overkill; you merely
+ * need to know that a particular work item isn't queued and isn't running.
+ * In such cases you should use cancel_delayed_work_sync() or
+ * cancel_work_sync() instead.
+ */
 void flush_scheduled_work(void)
 {
         flush_workqueue(keventd_wq);
@@ -1076,7 +1110,7 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb,
         unsigned int cpu = (unsigned long)hcpu;
         struct cpu_workqueue_struct *cwq;
         struct workqueue_struct *wq;
-        int ret = NOTIFY_OK;
+        int err = 0;
 
         action &= ~CPU_TASKS_FROZEN;
 
@@ -1090,12 +1124,13 @@ undo:
 
                 switch (action) {
                 case CPU_UP_PREPARE:
-                        if (!create_workqueue_thread(cwq, cpu))
+                        err = create_workqueue_thread(cwq, cpu);
+                        if (!err)
                                 break;
                         printk(KERN_ERR "workqueue [%s] for %i failed\n",
                                 wq->name, cpu);
                         action = CPU_UP_CANCELED;
-                        ret = NOTIFY_BAD;
+                        err = -ENOMEM;
                         goto undo;
 
                 case CPU_ONLINE:
@@ -1116,7 +1151,7 @@ undo:
                 cpumask_clear_cpu(cpu, cpu_populated_map);
         }
 
-        return ret;
+        return notifier_from_errno(err);
 }
 
 #ifdef CONFIG_SMP