---

yaml
---
r: 273802
b: refs/heads/master
c: c9a929d
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: bd87b5898a72b1aef6acf3705c61c9f6372adf0c
+refs/heads/master: c9a929dde3913780b5c416f4bb9d9ed804f509ce

trunk/block/blk-core.c

@@ -349,21 +349,29 @@ EXPORT_SYMBOL(blk_put_queue);
 /**
  * blk_drain_queue - drain requests from request_queue
  * @q: queue to drain
+ * @drain_all: whether to drain all requests or only the ones w/ ELVPRIV
  *
- * Drain ELV_PRIV requests from @q.  The caller is responsible for ensuring
- * that no new requests which need to be drained are queued.
+ * Drain requests from @q.  If @drain_all is set, all requests are drained.
+ * If not, only ELVPRIV requests are drained.  The caller is responsible
+ * for ensuring that no new requests which need to be drained are queued.
  */
-void blk_drain_queue(struct request_queue *q)
+void blk_drain_queue(struct request_queue *q, bool drain_all)
 {
 	while (true) {
 		int nr_rqs;
 
 		spin_lock_irq(q->queue_lock);
 
 		elv_drain_elevator(q);
+		if (drain_all)
+			blk_throtl_drain(q);
 
 		__blk_run_queue(q);
-		nr_rqs = q->rq.elvpriv;
+
+		if (drain_all)
+			nr_rqs = q->rq.count[0] + q->rq.count[1];
+		else
+			nr_rqs = q->rq.elvpriv;
 
 		spin_unlock_irq(q->queue_lock);
 
@@ -373,30 +381,40 @@ void blk_drain_queue(struct request_queue *q)
 	}
 }
 
-/*
- * Note: If a driver supplied the queue lock, it is disconnected
- * by this function. The actual state of the lock doesn't matter
- * here as the request_queue isn't accessible after this point
- * (QUEUE_FLAG_DEAD is set) and no other requests will be queued.
+/**
+ * blk_cleanup_queue - shutdown a request queue
+ * @q: request queue to shutdown
+ *
+ * Mark @q DEAD, drain all pending requests, destroy and put it.  All
+ * future requests will be failed immediately with -ENODEV.
  */
 void blk_cleanup_queue(struct request_queue *q)
 {
-	/*
-	 * We know we have process context here, so we can be a little
-	 * cautious and ensure that pending block actions on this device
-	 * are done before moving on. Going into this function, we should
-	 * not have processes doing IO to this device.
-	 */
-	blk_sync_queue(q);
+	spinlock_t *lock = q->queue_lock;
 
-	del_timer_sync(&q->backing_dev_info.laptop_mode_wb_timer);
+	/* mark @q DEAD, no new request or merges will be allowed afterwards */
 	mutex_lock(&q->sysfs_lock);
 	queue_flag_set_unlocked(QUEUE_FLAG_DEAD, q);
-	mutex_unlock(&q->sysfs_lock);
+
+	spin_lock_irq(lock);
+	queue_flag_set(QUEUE_FLAG_NOMERGES, q);
+	queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
+	queue_flag_set(QUEUE_FLAG_DEAD, q);
 
 	if (q->queue_lock != &q->__queue_lock)
 		q->queue_lock = &q->__queue_lock;
 
+	spin_unlock_irq(lock);
+	mutex_unlock(&q->sysfs_lock);
+
+	/* drain all requests queued before DEAD marking */
+	blk_drain_queue(q, true);
+
+	/* @q won't process any more request, flush async actions */
+	del_timer_sync(&q->backing_dev_info.laptop_mode_wb_timer);
+	blk_sync_queue(q);
+
+	/* @q is and will stay empty, shutdown and put */
 	blk_put_queue(q);
 }
 EXPORT_SYMBOL(blk_cleanup_queue);
@@ -1509,9 +1527,6 @@ generic_make_request_checks(struct bio *bio)
 		goto end_io;
 	}
 
-	if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)))
-		goto end_io;
-
 	part = bio->bi_bdev->bd_part;
 	if (should_fail_request(part, bio->bi_size) ||
 	    should_fail_request(&part_to_disk(part)->part0,

trunk/block/blk-sysfs.c

@@ -490,6 +490,7 @@ static void blk_release_queue(struct kobject *kobj)
 	if (q->queue_tags)
 		__blk_queue_free_tags(q);
 
+	blk_throtl_release(q);
 	blk_trace_shutdown(q);
 
 	bdi_destroy(&q->backing_dev_info);

trunk/block/blk-throttle.c

@@ -309,6 +309,10 @@ static struct throtl_grp * throtl_get_tg(struct throtl_data *td)
 	struct blkio_cgroup *blkcg;
 	struct request_queue *q = td->queue;
 
+	/* no throttling for dead queue */
+	if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)))
+		return NULL;
+
 	rcu_read_lock();
 	blkcg = task_blkio_cgroup(current);
 	tg = throtl_find_tg(td, blkcg);
@@ -1001,11 +1005,6 @@ static void throtl_release_tgs(struct throtl_data *td)
 	}
 }
 
-static void throtl_td_free(struct throtl_data *td)
-{
-	kfree(td);
-}
-
 /*
  * Blk cgroup controller notification saying that blkio_group object is being
  * delinked as associated cgroup object is going away. That also means that
@@ -1204,6 +1203,41 @@ bool blk_throtl_bio(struct request_queue *q, struct bio *bio)
 	return throttled;
 }
 
+/**
+ * blk_throtl_drain - drain throttled bios
+ * @q: request_queue to drain throttled bios for
+ *
+ * Dispatch all currently throttled bios on @q through ->make_request_fn().
+ */
+void blk_throtl_drain(struct request_queue *q)
+	__releases(q->queue_lock) __acquires(q->queue_lock)
+{
+	struct throtl_data *td = q->td;
+	struct throtl_rb_root *st = &td->tg_service_tree;
+	struct throtl_grp *tg;
+	struct bio_list bl;
+	struct bio *bio;
+
+	lockdep_is_held(q->queue_lock);
+
+	bio_list_init(&bl);
+
+	while ((tg = throtl_rb_first(st))) {
+		throtl_dequeue_tg(td, tg);
+
+		while ((bio = bio_list_peek(&tg->bio_lists[READ])))
+			tg_dispatch_one_bio(td, tg, bio_data_dir(bio), &bl);
+		while ((bio = bio_list_peek(&tg->bio_lists[WRITE])))
+			tg_dispatch_one_bio(td, tg, bio_data_dir(bio), &bl);
+	}
+	spin_unlock_irq(q->queue_lock);
+
+	while ((bio = bio_list_pop(&bl)))
+		generic_make_request(bio);
+
+	spin_lock_irq(q->queue_lock);
+}
+
 int blk_throtl_init(struct request_queue *q)
 {
 	struct throtl_data *td;
@@ -1276,7 +1310,11 @@ void blk_throtl_exit(struct request_queue *q)
 	 * it.
 	 */
 	throtl_shutdown_wq(q);
-	throtl_td_free(td);
+}
+
+void blk_throtl_release(struct request_queue *q)
+{
+	kfree(q->td);
 }
 
 static int __init throtl_init(void)

trunk/block/blk.h

@@ -15,7 +15,7 @@ void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
 			struct bio *bio);
 int blk_rq_append_bio(struct request_queue *q, struct request *rq,
 		      struct bio *bio);
-void blk_drain_queue(struct request_queue *q);
+void blk_drain_queue(struct request_queue *q, bool drain_all);
 void blk_dequeue_request(struct request *rq);
 void __blk_queue_free_tags(struct request_queue *q);
 bool __blk_end_bidi_request(struct request *rq, int error,
@@ -191,15 +191,19 @@ static inline int blk_do_io_stat(struct request *rq)
 
 #ifdef CONFIG_BLK_DEV_THROTTLING
 extern bool blk_throtl_bio(struct request_queue *q, struct bio *bio);
+extern void blk_throtl_drain(struct request_queue *q);
 extern int blk_throtl_init(struct request_queue *q);
 extern void blk_throtl_exit(struct request_queue *q);
+extern void blk_throtl_release(struct request_queue *q);
 #else /* CONFIG_BLK_DEV_THROTTLING */
 static inline bool blk_throtl_bio(struct request_queue *q, struct bio *bio)
 {
 	return false;
 }
+static inline void blk_throtl_drain(struct request_queue *q) { }
 static inline int blk_throtl_init(struct request_queue *q) { return 0; }
 static inline void blk_throtl_exit(struct request_queue *q) { }
+static inline void blk_throtl_release(struct request_queue *q) { }
 #endif /* CONFIG_BLK_DEV_THROTTLING */
 
 #endif /* BLK_INTERNAL_H */

trunk/block/elevator.c

@@ -626,7 +626,7 @@ void elv_quiesce_start(struct request_queue *q)
 	queue_flag_set(QUEUE_FLAG_ELVSWITCH, q);
 	spin_unlock_irq(q->queue_lock);
 
-	blk_drain_queue(q);
+	blk_drain_queue(q, false);
 }
 
 void elv_quiesce_end(struct request_queue *q)