Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso...

[linux-imx.git] / kernel / workqueue.c

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 0b72e816b8d0126f0a3e72c1f3a2496fc3545030..7f5d4be220345b0899d38ced692f2458b9278ce7 100644 (file)
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -2817,6 +2817,19 @@ already_gone:
        return false;
 }
 
+static bool __flush_work(struct work_struct *work)
+{
+       struct wq_barrier barr;
+
+       if (start_flush_work(work, &barr)) {
+               wait_for_completion(&barr.done);
+               destroy_work_on_stack(&barr.work);
+               return true;
+       } else {
+               return false;
+       }
+}
+
 /**
  * flush_work - wait for a work to finish executing the last queueing instance
  * @work: the work to flush
@@ -2830,18 +2843,10 @@ already_gone:
  */
 bool flush_work(struct work_struct *work)
 {
-       struct wq_barrier barr;
-
        lock_map_acquire(&work->lockdep_map);
        lock_map_release(&work->lockdep_map);
 
-       if (start_flush_work(work, &barr)) {
-               wait_for_completion(&barr.done);
-               destroy_work_on_stack(&barr.work);
-               return true;
-       } else {
-               return false;
-       }
+       return __flush_work(work);
 }
 EXPORT_SYMBOL_GPL(flush_work);
 
@@ -3411,6 +3416,12 @@ static void copy_workqueue_attrs(struct workqueue_attrs *to,
 {
        to->nice = from->nice;
        cpumask_copy(to->cpumask, from->cpumask);
+       /*
+        * Unlike hash and equality test, this function doesn't ignore
+        * ->no_numa as it is used for both pool and wq attrs.  Instead,
+        * get_unbound_pool() explicitly clears ->no_numa after copying.
+        */
+       to->no_numa = from->no_numa;
 }
 
 /* hash value of the content of @attr */
@@ -3578,6 +3589,12 @@ static struct worker_pool *get_unbound_pool(const struct workqueue_attrs *attrs)
        lockdep_set_subclass(&pool->lock, 1);   /* see put_pwq() */
        copy_workqueue_attrs(pool->attrs, attrs);
 
+       /*
+        * no_numa isn't a worker_pool attribute, always clear it.  See
+        * 'struct workqueue_attrs' comments for detail.
+        */
+       pool->attrs->no_numa = false;
+
        /* if cpumask is contained inside a NUMA node, we belong to that node */
        if (wq_numa_enabled) {
                for_each_node(node) {
@@ -4756,7 +4773,14 @@ long work_on_cpu(int cpu, long (*fn)(void *), void *arg)
 
        INIT_WORK_ONSTACK(&wfc.work, work_for_cpu_fn);
        schedule_work_on(cpu, &wfc.work);
-       flush_work(&wfc.work);
+
+       /*
+        * The work item is on-stack and can't lead to deadlock through
+        * flushing.  Use __flush_work() to avoid spurious lockdep warnings
+        * when work_on_cpu()s are nested.
+        */
+       __flush_work(&wfc.work);
+
        return wfc.ret;
 }
 EXPORT_SYMBOL_GPL(work_on_cpu);