Merge branch 'for-linus' of git://git.kernel.dk/linux-block

Pull block layer fixes from Jens Axboe:
 "The major part is an update to the NVMe driver, fixing various issues
  around surprise removal and hung controllers.  Most of that is from
  Keith, and parts are simple blk-mq fixes or exports/additions of minor
  functions to aid this effort, and parts are changes directly to the
  NVMe driver.

  Apart from the above, this contains:

   - Small blk-mq change from me, killing an unused member of the
     hardware queue structure.

   - Small fix from Ming Lei, fixing up a few drivers that didn't
     properly check for ERR_PTR() returns from blk_mq_init_queue()"

* 'for-linus' of git://git.kernel.dk/linux-block:
  NVMe: Fix locking on abort handling
  NVMe: Start and stop h/w queues on reset
  NVMe: Command abort handling fixes
  NVMe: Admin queue removal handling
  NVMe: Reference count admin queue usage
  NVMe: Start all requests
  blk-mq: End unstarted requests on a dying queue
  blk-mq: Allow requests to never expire
  blk-mq: Add helper to abort requeued requests
  blk-mq: Let drivers cancel requeue_work
  blk-mq: Export if requests were started
  blk-mq: Wake tasks entering queue on dying
  blk-mq: get rid of ->cmd_size in the hardware queue
  block: fix checking return value of blk_mq_init_queue
  block: wake up waiters when a queue is marked dying
  NVMe: Fix double free irq
  blk-mq: Export freeze/unfreeze functions
  blk-mq: Exit queue on alloc failure

block/blk-core.c

@@ -473,6 +473,25 @@ void blk_queue_bypass_end(struct request_queue *q)
 }
 EXPORT_SYMBOL_GPL(blk_queue_bypass_end);
 
+void blk_set_queue_dying(struct request_queue *q)
+{
+	queue_flag_set_unlocked(QUEUE_FLAG_DYING, q);
+
+	if (q->mq_ops)
+		blk_mq_wake_waiters(q);
+	else {
+		struct request_list *rl;
+
+		blk_queue_for_each_rl(rl, q) {
+			if (rl->rq_pool) {
+				wake_up(&rl->wait[BLK_RW_SYNC]);
+				wake_up(&rl->wait[BLK_RW_ASYNC]);
+			}
+		}
+	}
+}
+EXPORT_SYMBOL_GPL(blk_set_queue_dying);
+
 /**
  * blk_cleanup_queue - shutdown a request queue
  * @q: request queue to shutdown
@@ -486,7 +505,7 @@ void blk_cleanup_queue(struct request_queue *q)
 
 	/* mark @q DYING, no new request or merges will be allowed afterwards */
 	mutex_lock(&q->sysfs_lock);
-	queue_flag_set_unlocked(QUEUE_FLAG_DYING, q);
+	blk_set_queue_dying(q);
 	spin_lock_irq(lock);
 
 	/*

block/blk-mq-tag.c

@@ -68,9 +68,9 @@ bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx)
 }
 
 /*
- * Wakeup all potentially sleeping on normal (non-reserved) tags
+ * Wakeup all potentially sleeping on tags
  */
-static void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags)
+void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags, bool include_reserve)
 {
 	struct blk_mq_bitmap_tags *bt;
 	int i, wake_index;
@@ -85,6 +85,12 @@ static void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags)
 
 		wake_index = bt_index_inc(wake_index);
 	}
+
+	if (include_reserve) {
+		bt = &tags->breserved_tags;
+		if (waitqueue_active(&bt->bs[0].wait))
+			wake_up(&bt->bs[0].wait);
+	}
 }
 
 /*
@@ -100,7 +106,7 @@ void __blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx)
 
 	atomic_dec(&tags->active_queues);
 
-	blk_mq_tag_wakeup_all(tags);
+	blk_mq_tag_wakeup_all(tags, false);
 }
 
 /*
@@ -584,7 +590,7 @@ int blk_mq_tag_update_depth(struct blk_mq_tags *tags, unsigned int tdepth)
 	 * static and should never need resizing.
 	 */
 	bt_update_count(&tags->bitmap_tags, tdepth);
-	blk_mq_tag_wakeup_all(tags);
+	blk_mq_tag_wakeup_all(tags, false);
 	return 0;
 }
 

block/blk-mq-tag.h

@@ -54,6 +54,7 @@ extern bool blk_mq_has_free_tags(struct blk_mq_tags *tags);
 extern ssize_t blk_mq_tag_sysfs_show(struct blk_mq_tags *tags, char *page);
 extern void blk_mq_tag_init_last_tag(struct blk_mq_tags *tags, unsigned int *last_tag);
 extern int blk_mq_tag_update_depth(struct blk_mq_tags *tags, unsigned int depth);
+extern void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags, bool);
 
 enum {
 	BLK_MQ_TAG_CACHE_MIN	= 1,

block/blk-mq.c

@@ -107,7 +107,7 @@ static void blk_mq_usage_counter_release(struct percpu_ref *ref)
 	wake_up_all(&q->mq_freeze_wq);
 }
 
-static void blk_mq_freeze_queue_start(struct request_queue *q)
+void blk_mq_freeze_queue_start(struct request_queue *q)
 {
 	bool freeze;
 
@@ -120,6 +120,7 @@ static void blk_mq_freeze_queue_start(struct request_queue *q)
 		blk_mq_run_queues(q, false);
 	}
 }
+EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_start);
 
 static void blk_mq_freeze_queue_wait(struct request_queue *q)
 {
@@ -136,7 +137,7 @@ void blk_mq_freeze_queue(struct request_queue *q)
 	blk_mq_freeze_queue_wait(q);
 }
 
-static void blk_mq_unfreeze_queue(struct request_queue *q)
+void blk_mq_unfreeze_queue(struct request_queue *q)
 {
 	bool wake;
 
@@ -149,6 +150,24 @@ static void blk_mq_unfreeze_queue(struct request_queue *q)
 		wake_up_all(&q->mq_freeze_wq);
 	}
 }
+EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue);
+
+void blk_mq_wake_waiters(struct request_queue *q)
+{
+	struct blk_mq_hw_ctx *hctx;
+	unsigned int i;
+
+	queue_for_each_hw_ctx(q, hctx, i)
+		if (blk_mq_hw_queue_mapped(hctx))
+			blk_mq_tag_wakeup_all(hctx->tags, true);
+
+	/*
+	 * If we are called because the queue has now been marked as
+	 * dying, we need to ensure that processes currently waiting on
+	 * the queue are notified as well.
+	 */
+	wake_up_all(&q->mq_freeze_wq);
+}
 
 bool blk_mq_can_queue(struct blk_mq_hw_ctx *hctx)
 {
@@ -258,8 +277,10 @@ struct request *blk_mq_alloc_request(struct request_queue *q, int rw, gfp_t gfp,
 		ctx = alloc_data.ctx;
 	}
 	blk_mq_put_ctx(ctx);
-	if (!rq)
+	if (!rq) {
+		blk_mq_queue_exit(q);
 		return ERR_PTR(-EWOULDBLOCK);
+	}
 	return rq;
 }
 EXPORT_SYMBOL(blk_mq_alloc_request);
@@ -383,6 +404,12 @@ void blk_mq_complete_request(struct request *rq)
 }
 EXPORT_SYMBOL(blk_mq_complete_request);
 
+int blk_mq_request_started(struct request *rq)
+{
+	return test_bit(REQ_ATOM_STARTED, &rq->atomic_flags);
+}
+EXPORT_SYMBOL_GPL(blk_mq_request_started);
+
 void blk_mq_start_request(struct request *rq)
 {
 	struct request_queue *q = rq->q;
@@ -500,12 +527,38 @@ void blk_mq_add_to_requeue_list(struct request *rq, bool at_head)
 }
 EXPORT_SYMBOL(blk_mq_add_to_requeue_list);
 
+void blk_mq_cancel_requeue_work(struct request_queue *q)
+{
+	cancel_work_sync(&q->requeue_work);
+}
+EXPORT_SYMBOL_GPL(blk_mq_cancel_requeue_work);
+
 void blk_mq_kick_requeue_list(struct request_queue *q)
 {
 	kblockd_schedule_work(&q->requeue_work);
 }
 EXPORT_SYMBOL(blk_mq_kick_requeue_list);
 
+void blk_mq_abort_requeue_list(struct request_queue *q)
+{
+	unsigned long flags;
+	LIST_HEAD(rq_list);
+
+	spin_lock_irqsave(&q->requeue_lock, flags);
+	list_splice_init(&q->requeue_list, &rq_list);
+	spin_unlock_irqrestore(&q->requeue_lock, flags);
+
+	while (!list_empty(&rq_list)) {
+		struct request *rq;
+
+		rq = list_first_entry(&rq_list, struct request, queuelist);
+		list_del_init(&rq->queuelist);
+		rq->errors = -EIO;
+		blk_mq_end_request(rq, rq->errors);
+	}
+}
+EXPORT_SYMBOL(blk_mq_abort_requeue_list);
+
 static inline bool is_flush_request(struct request *rq,
 		struct blk_flush_queue *fq, unsigned int tag)
 {
@@ -566,13 +619,24 @@ void blk_mq_rq_timed_out(struct request *req, bool reserved)
 		break;
 	}
 }
-		
+
 static void blk_mq_check_expired(struct blk_mq_hw_ctx *hctx,
 		struct request *rq, void *priv, bool reserved)
 {
 	struct blk_mq_timeout_data *data = priv;
 
-	if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags))
+	if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) {
+		/*
+		 * If a request wasn't started before the queue was
+		 * marked dying, kill it here or it'll go unnoticed.
+		 */
+		if (unlikely(blk_queue_dying(rq->q))) {
+			rq->errors = -EIO;
+			blk_mq_complete_request(rq);
+		}
+		return;
+	}
+	if (rq->cmd_flags & REQ_NO_TIMEOUT)
 		return;
 
 	if (time_after_eq(jiffies, rq->deadline)) {
@@ -1601,7 +1665,6 @@ static int blk_mq_init_hctx(struct request_queue *q,
 	hctx->queue = q;
 	hctx->queue_num = hctx_idx;
 	hctx->flags = set->flags;
-	hctx->cmd_size = set->cmd_size;
 
 	blk_mq_init_cpu_notifier(&hctx->cpu_notifier,
 					blk_mq_hctx_notify, hctx);

block/blk-mq.h

@@ -32,6 +32,7 @@ void blk_mq_free_queue(struct request_queue *q);
 void blk_mq_clone_flush_request(struct request *flush_rq,
 		struct request *orig_rq);
 int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
+void blk_mq_wake_waiters(struct request_queue *q);
 
 /*
  * CPU hotplug helpers

block/blk-timeout.c

@@ -190,6 +190,9 @@ void blk_add_timer(struct request *req)
 	struct request_queue *q = req->q;
 	unsigned long expiry;
 
+	if (req->cmd_flags & REQ_NO_TIMEOUT)
+		return;
+
 	/* blk-mq has its own handler, so we don't need ->rq_timed_out_fn */
 	if (!q->mq_ops && !q->rq_timed_out_fn)
 		return;

drivers/block/null_blk.c

@@ -530,7 +530,7 @@ static int null_add_dev(void)
 			goto out_cleanup_queues;
 
 		nullb->q = blk_mq_init_queue(&nullb->tag_set);
-		if (!nullb->q) {
+		if (IS_ERR(nullb->q)) {
 			rv = -ENOMEM;
 			goto out_cleanup_tags;
 		}