[PATCH] workqueue: improve the draining/destroying warning in __queue_work

[PATCH] workqueue: improve the draining/destroying warning in __queue_work

[Christoph Hellwig]

Tell which of the two conditions hit.  And to avoid makign the code even
harder to read, move the WARN_ONCE out of the condition triggering it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 kernel/workqueue.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index f2e8071a6f4e..bea294b00d1f 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -2428,15 +2428,19 @@ static void __queue_work(int cpu, struct workqueue_struct *wq,
 	lockdep_assert_irqs_disabled();
 
 	/*
-	 * For a draining wq, only works from the same workqueue are
-	 * allowed. The __WQ_DESTROYING helps to spot the issue that
-	 * queues a new work item to a wq after destroy_workqueue(wq).
+	 * For a draining wq, only works from the same workqueue are allowed.
+	 * The __WQ_DESTROYING helps to spot the issue that queues a new work
+	 * item to a wq after destroy_workqueue(wq).
 	 */
 	if (unlikely(wq->flags & (__WQ_DESTROYING | __WQ_DRAINING) &&
-		     WARN_ONCE(!is_chained_work(wq), "workqueue: cannot queue %ps on wq %s\n",
-			       work->func, wq->name))) {
+			!is_chained_work(wq))) {
 		struct work_offq_data offqd;
 
+		WARN_ONCE(1, "workqueue: cannot queue %ps on %s wq %s\n",
+			work->func, (wq->flags & __WQ_DESTROYING) ?
+				"destroying" : "draining",
+			wq->name);
+
 		/*
 		 * State on entry: PENDING is set, work is off-queue (no
 		 * insert_work() has run).
-- 
2.53.0