Revert "workqueue: allow work_on_cpu() to be called recursively"
This reverts commit c2fda509667b0fda4372a237f5a59ea4570b1627.
c2fda509667b removed lockdep annotation from work_on_cpu() to work around
the PCI path that calls work_on_cpu() from within a work_on_cpu() work item
(PF driver .probe() method -> pci_enable_sriov() -> add VFs -> VF driver
.probe method).
961da7fb6b22 ("PCI: Avoid unnecessary CPU switch when calling driver
.probe() method) avoids that recursive work_on_cpu() use in a different
way, so this revert restores the work_on_cpu() lockdep annotation.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Tejun Heo <tj@kernel.org>diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 987293d..5690b8e 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -2840,19 +2840,6 @@
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
@@ -2866,10 +2853,18 @@
*/
bool flush_work(struct work_struct *work)
{
+ struct wq_barrier barr;
+
lock_map_acquire(&work->lockdep_map);
lock_map_release(&work->lockdep_map);
- return __flush_work(work);
+ if (start_flush_work(work, &barr)) {
+ wait_for_completion(&barr.done);
+ destroy_work_on_stack(&barr.work);
+ return true;
+ } else {
+ return false;
+ }
}
EXPORT_SYMBOL_GPL(flush_work);
@@ -4814,14 +4809,7 @@
INIT_WORK_ONSTACK(&wfc.work, work_for_cpu_fn);
schedule_work_on(cpu, &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);
-
+ flush_work(&wfc.work);
return wfc.ret;
}
EXPORT_SYMBOL_GPL(work_on_cpu);