1 files changed, 69 insertions, 0 deletions
diff --git a/block/blk.h b/block/blk.h
index 46db5dc83dcb..b034fd2460c4 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -41,6 +41,75 @@ extern struct kmem_cache *request_cachep;
 extern struct kobj_type blk_queue_ktype;
 extern struct ida blk_queue_ida;
 
+/*
+ * @q->queue_lock is set while a queue is being initialized. Since we know
+ * that no other threads access the queue object before @q->queue_lock has
+ * been set, it is safe to manipulate queue flags without holding the
+ * queue_lock if @q->queue_lock == NULL. See also blk_alloc_queue_node() and
+ * blk_init_allocated_queue().
+ */
+static inline void queue_lockdep_assert_held(struct request_queue *q)
+{
+	if (q->queue_lock)
+		lockdep_assert_held(q->queue_lock);
+}
+
+static inline void queue_flag_set_unlocked(unsigned int flag,
+					   struct request_queue *q)
+{
+	if (test_bit(QUEUE_FLAG_INIT_DONE, &q->queue_flags) &&
+	    kref_read(&q->kobj.kref))
+		lockdep_assert_held(q->queue_lock);
+	__set_bit(flag, &q->queue_flags);
+}
+
+static inline void queue_flag_clear_unlocked(unsigned int flag,
+					     struct request_queue *q)
+{
+	if (test_bit(QUEUE_FLAG_INIT_DONE, &q->queue_flags) &&
+	    kref_read(&q->kobj.kref))
+		lockdep_assert_held(q->queue_lock);
+	__clear_bit(flag, &q->queue_flags);
+}
+
+static inline int queue_flag_test_and_clear(unsigned int flag,
+					    struct request_queue *q)
+{
+	queue_lockdep_assert_held(q);
+
+	if (test_bit(flag, &q->queue_flags)) {
+		__clear_bit(flag, &q->queue_flags);
+		return 1;
+	}
+
+	return 0;
+}
+
+static inline int queue_flag_test_and_set(unsigned int flag,
+					  struct request_queue *q)
+{
+	queue_lockdep_assert_held(q);
+
+	if (!test_bit(flag, &q->queue_flags)) {
+		__set_bit(flag, &q->queue_flags);
+		return 0;
+	}
+
+	return 1;
+}
+
+static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
+{
+	queue_lockdep_assert_held(q);
+	__set_bit(flag, &q->queue_flags);
+}
+
+static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
+{
+	queue_lockdep_assert_held(q);
+	__clear_bit(flag, &q->queue_flags);
+}
+
 static inline struct blk_flush_queue *blk_get_flush_queue(
 		struct request_queue *q, struct blk_mq_ctx *ctx)
 {