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

Pull block fixes and updates from Jens Axboe:
 "Some fixes and followup features/changes that should go in, in this
  merge window. This contains:

   - Two fixes for lightnvm from Javier, fixing problems in the new code
     merge previously in this merge window.

   - A fix from Jan for the backing device changes, fixing an issue in
     NFS that causes a failure to mount on certain setups.

   - A change from Christoph, cleaning up the blk-mq init and exit
     request paths.

   - Remove elevator_change(), which is now unused. From Bart.

   - A fix for queue operation invocation on a dead queue, from Bart.

   - A series fixing up mtip32xx for blk-mq scheduling, removing a
     bandaid we previously had in place for this. From me.

   - A regression fix for this series, fixing a case where we wait on
     workqueue flushing from an invalid (non-blocking) context. From me.

   - A fix/optimization from Ming, ensuring that we don't both quiesce
     and freeze a queue at the same time.

   - A fix from Peter on lock ordering for CPU hotplug. Not a real
     problem right now, but will be once the CPU hotplug rework goes in.

   - A series from Omar, cleaning up out blk-mq debugfs support, and
     adding support for exporting info from schedulers in debugfs as
     well. This is really useful in debugging stalls or livelocks. From
     Omar"

* 'for-linus' of git://git.kernel.dk/linux-block: (28 commits)
  mq-deadline: add debugfs attributes
  kyber: add debugfs attributes
  blk-mq-debugfs: allow schedulers to register debugfs attributes
  blk-mq: untangle debugfs and sysfs
  blk-mq: move debugfs declarations to a separate header file
  blk-mq: Do not invoke queue operations on a dead queue
  blk-mq-debugfs: get rid of a bunch of boilerplate
  blk-mq-debugfs: rename hw queue directories from <n> to hctx<n>
  blk-mq-debugfs: don't open code strstrip()
  blk-mq-debugfs: error on long write to queue "state" file
  blk-mq-debugfs: clean up flag definitions
  blk-mq-debugfs: separate flags with |
  nfs: Fix bdi handling for cloned superblocks
  block/mq: Cure cpu hotplug lock inversion
  lightnvm: fix bad back free on error path
  lightnvm: create cmd before allocating request
  blk-mq: don't use sync workqueue flushing from drivers
  mtip32xx: convert internal commands to regular block infrastructure
  mtip32xx: cleanup internal tag assumptions
  block: don't call blk_mq_quiesce_queue() after queue is frozen
  ...

block/blk-core.c

@@ -561,13 +561,9 @@ void blk_cleanup_queue(struct request_queue *q)
 	 * prevent that q->request_fn() gets invoked after draining finished.
 	 */
 	blk_freeze_queue(q);
-	if (!q->mq_ops) {
-		spin_lock_irq(lock);
+	spin_lock_irq(lock);
+	if (!q->mq_ops)
 		__blk_drain_queue(q, true);
-	} else {
-		blk_mq_debugfs_unregister_mq(q);
-		spin_lock_irq(lock);
-	}
 	queue_flag_set(QUEUE_FLAG_DEAD, q);
 	spin_unlock_irq(lock);
 

block/blk-mq-debugfs.h

+#ifndef INT_BLK_MQ_DEBUGFS_H
+#define INT_BLK_MQ_DEBUGFS_H
+
+#ifdef CONFIG_BLK_DEBUG_FS
+
+#include <linux/seq_file.h>
+
+struct blk_mq_debugfs_attr {
+	const char *name;
+	umode_t mode;
+	int (*show)(void *, struct seq_file *);
+	ssize_t (*write)(void *, const char __user *, size_t, loff_t *);
+	/* Set either .show or .seq_ops. */
+	const struct seq_operations *seq_ops;
+};
+
+int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq);
+int blk_mq_debugfs_rq_show(struct seq_file *m, void *v);
+
+int blk_mq_debugfs_register(struct request_queue *q);
+void blk_mq_debugfs_unregister(struct request_queue *q);
+int blk_mq_debugfs_register_hctx(struct request_queue *q,
+				 struct blk_mq_hw_ctx *hctx);
+void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx);
+int blk_mq_debugfs_register_hctxs(struct request_queue *q);
+void blk_mq_debugfs_unregister_hctxs(struct request_queue *q);
+
+int blk_mq_debugfs_register_sched(struct request_queue *q);
+void blk_mq_debugfs_unregister_sched(struct request_queue *q);
+int blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
+				       struct blk_mq_hw_ctx *hctx);
+void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx);
+#else
+static inline int blk_mq_debugfs_register(struct request_queue *q)
+{
+	return 0;
+}
+
+static inline void blk_mq_debugfs_unregister(struct request_queue *q)
+{
+}
+
+static inline int blk_mq_debugfs_register_hctx(struct request_queue *q,
+					       struct blk_mq_hw_ctx *hctx)
+{
+	return 0;
+}
+
+static inline void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx)
+{
+}
+
+static inline int blk_mq_debugfs_register_hctxs(struct request_queue *q)
+{
+	return 0;
+}
+
+static inline void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
+{
+}
+
+static inline int blk_mq_debugfs_register_sched(struct request_queue *q)
+{
+	return 0;
+}
+
+static inline void blk_mq_debugfs_unregister_sched(struct request_queue *q)
+{
+}
+
+static inline int blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
+						     struct blk_mq_hw_ctx *hctx)
+{
+	return 0;
+}
+
+static inline void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)
+{
+}
+#endif
+
+#endif

block/blk-mq-sched.c

@@ -11,6 +11,7 @@
 
 #include "blk.h"
 #include "blk-mq.h"
+#include "blk-mq-debugfs.h"
 #include "blk-mq-sched.h"
 #include "blk-mq-tag.h"
 #include "blk-wbt.h"
@@ -82,11 +83,7 @@ struct request *blk_mq_sched_get_request(struct request_queue *q,
 	if (likely(!data->hctx))
 		data->hctx = blk_mq_map_queue(q, data->ctx->cpu);
 
-	/*
-	 * For a reserved tag, allocate a normal request since we might
-	 * have driver dependencies on the value of the internal tag.
-	 */
-	if (e && !(data->flags & BLK_MQ_REQ_RESERVED)) {
+	if (e) {
 		data->flags |= BLK_MQ_REQ_INTERNAL;
 
 		/*
@@ -476,6 +473,8 @@ int blk_mq_sched_init_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx,
 		}
 	}
 
+	blk_mq_debugfs_register_sched_hctx(q, hctx);
+
 	return 0;
 }
 
@@ -487,6 +486,8 @@ void blk_mq_sched_exit_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx,
 	if (!e)
 		return;
 
+	blk_mq_debugfs_unregister_sched_hctx(hctx);
+
 	if (e->type->ops.mq.exit_hctx && hctx->sched_data) {
 		e->type->ops.mq.exit_hctx(hctx, hctx_idx);
 		hctx->sched_data = NULL;
@@ -523,8 +524,10 @@ int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e)
 	if (ret)
 		goto err;
 
-	if (e->ops.mq.init_hctx) {
-		queue_for_each_hw_ctx(q, hctx, i) {
+	blk_mq_debugfs_register_sched(q);
+
+	queue_for_each_hw_ctx(q, hctx, i) {
+		if (e->ops.mq.init_hctx) {
 			ret = e->ops.mq.init_hctx(hctx, i);
 			if (ret) {
 				eq = q->elevator;
@@ -533,6 +536,7 @@ int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e)
 				return ret;
 			}
 		}
+		blk_mq_debugfs_register_sched_hctx(q, hctx);
 	}
 
 	return 0;
@@ -548,14 +552,14 @@ void blk_mq_exit_sched(struct request_queue *q, struct elevator_queue *e)
 	struct blk_mq_hw_ctx *hctx;
 	unsigned int i;
 
-	if (e->type->ops.mq.exit_hctx) {
-		queue_for_each_hw_ctx(q, hctx, i) {
-			if (hctx->sched_data) {
-				e->type->ops.mq.exit_hctx(hctx, i);
-				hctx->sched_data = NULL;
-			}
+	queue_for_each_hw_ctx(q, hctx, i) {
+		blk_mq_debugfs_unregister_sched_hctx(hctx);
+		if (e->type->ops.mq.exit_hctx && hctx->sched_data) {
+			e->type->ops.mq.exit_hctx(hctx, i);
+			hctx->sched_data = NULL;
 		}
 	}
+	blk_mq_debugfs_unregister_sched(q);
 	if (e->type->ops.mq.exit_sched)
 		e->type->ops.mq.exit_sched(e);
 	blk_mq_sched_tags_teardown(q);

block/blk-mq-sysfs.c

@@ -258,8 +258,6 @@ static void __blk_mq_unregister_dev(struct device *dev, struct request_queue *q)
 	queue_for_each_hw_ctx(q, hctx, i)
 		blk_mq_unregister_hctx(hctx);
 
-	blk_mq_debugfs_unregister_mq(q);
-
 	kobject_uevent(&q->mq_kobj, KOBJ_REMOVE);
 	kobject_del(&q->mq_kobj);
 	kobject_put(&dev->kobj);
@@ -318,8 +316,6 @@ int __blk_mq_register_dev(struct device *dev, struct request_queue *q)
 
 	kobject_uevent(&q->mq_kobj, KOBJ_ADD);
 
-	blk_mq_debugfs_register(q);
-
 	queue_for_each_hw_ctx(q, hctx, i) {
 		ret = blk_mq_register_hctx(hctx);
 		if (ret)
@@ -335,8 +331,6 @@ int __blk_mq_register_dev(struct device *dev, struct request_queue *q)
 	while (--i >= 0)
 		blk_mq_unregister_hctx(q->queue_hw_ctx[i]);
 
-	blk_mq_debugfs_unregister_mq(q);
-
 	kobject_uevent(&q->mq_kobj, KOBJ_REMOVE);
 	kobject_del(&q->mq_kobj);
 	kobject_put(&dev->kobj);
@@ -364,8 +358,6 @@ void blk_mq_sysfs_unregister(struct request_queue *q)
 	if (!q->mq_sysfs_init_done)
 		goto unlock;
 
-	blk_mq_debugfs_unregister_mq(q);
-
 	queue_for_each_hw_ctx(q, hctx, i)
 		blk_mq_unregister_hctx(hctx);
 
@@ -382,8 +374,6 @@ int blk_mq_sysfs_register(struct request_queue *q)
 	if (!q->mq_sysfs_init_done)
 		goto unlock;
 
-	blk_mq_debugfs_register_mq(q);
-
 	queue_for_each_hw_ctx(q, hctx, i) {
 		ret = blk_mq_register_hctx(hctx);
 		if (ret)

block/blk-mq.c

@@ -31,6 +31,7 @@
 #include <linux/blk-mq.h>
 #include "blk.h"
 #include "blk-mq.h"
+#include "blk-mq-debugfs.h"
 #include "blk-mq-tag.h"
 #include "blk-stat.h"
 #include "blk-wbt.h"
@@ -41,6 +42,7 @@ static LIST_HEAD(all_q_list);
 
 static void blk_mq_poll_stats_start(struct request_queue *q);
 static void blk_mq_poll_stats_fn(struct blk_stat_callback *cb);
+static void __blk_mq_stop_hw_queues(struct request_queue *q, bool sync);
 
 static int blk_mq_poll_stats_bkt(const struct request *rq)
 {
@@ -166,7 +168,7 @@ void blk_mq_quiesce_queue(struct request_queue *q)
 	unsigned int i;
 	bool rcu = false;
 
-	blk_mq_stop_hw_queues(q);
+	__blk_mq_stop_hw_queues(q, true);
 
 	queue_for_each_hw_ctx(q, hctx, i) {
 		if (hctx->flags & BLK_MQ_F_BLOCKING)
@@ -1218,20 +1220,34 @@ bool blk_mq_queue_stopped(struct request_queue *q)
 }
 EXPORT_SYMBOL(blk_mq_queue_stopped);
 
-void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx)
+static void __blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx, bool sync)
 {
-	cancel_delayed_work_sync(&hctx->run_work);
+	if (sync)
+		cancel_delayed_work_sync(&hctx->run_work);
+	else
+		cancel_delayed_work(&hctx->run_work);
+
 	set_bit(BLK_MQ_S_STOPPED, &hctx->state);
 }
+
+void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx)
+{
+	__blk_mq_stop_hw_queue(hctx, false);
+}
 EXPORT_SYMBOL(blk_mq_stop_hw_queue);
 
-void blk_mq_stop_hw_queues(struct request_queue *q)
+void __blk_mq_stop_hw_queues(struct request_queue *q, bool sync)
 {
 	struct blk_mq_hw_ctx *hctx;
 	int i;
 
 	queue_for_each_hw_ctx(q, hctx, i)
-		blk_mq_stop_hw_queue(hctx);
+		__blk_mq_stop_hw_queue(hctx, sync);
+}
+
+void blk_mq_stop_hw_queues(struct request_queue *q)
+{
+	__blk_mq_stop_hw_queues(q, false);
 }
 EXPORT_SYMBOL(blk_mq_stop_hw_queues);
 
@@ -1655,8 +1671,7 @@ void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
 
 			if (!rq)
 				continue;
-			set->ops->exit_request(set->driver_data, rq,
-						hctx_idx, i);
+			set->ops->exit_request(set, rq, hctx_idx);
 			tags->static_rqs[i] = NULL;
 		}
 	}
@@ -1787,8 +1802,7 @@ int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
 
 			tags->static_rqs[i] = rq;
 			if (set->ops->init_request) {
-				if (set->ops->init_request(set->driver_data,
-						rq, hctx_idx, i,
+				if (set->ops->init_request(set, rq, hctx_idx,
 						node)) {
 					tags->static_rqs[i] = NULL;
 					goto fail;
@@ -1849,14 +1863,12 @@ static void blk_mq_exit_hctx(struct request_queue *q,
 		struct blk_mq_tag_set *set,
 		struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx)
 {
-	unsigned flush_start_tag = set->queue_depth;
+	blk_mq_debugfs_unregister_hctx(hctx);
 
 	blk_mq_tag_idle(hctx);
 
 	if (set->ops->exit_request)
-		set->ops->exit_request(set->driver_data,
-				       hctx->fq->flush_rq, hctx_idx,
-				       flush_start_tag + hctx_idx);
+		set->ops->exit_request(set, hctx->fq->flush_rq, hctx_idx);
 
 	blk_mq_sched_exit_hctx(q, hctx, hctx_idx);
 
@@ -1889,7 +1901,6 @@ static int blk_mq_init_hctx(struct request_queue *q,
 		struct blk_mq_hw_ctx *hctx, unsigned hctx_idx)
 {
 	int node;
-	unsigned flush_start_tag = set->queue_depth;
 
 	node = hctx->numa_node;
 	if (node == NUMA_NO_NODE)
@@ -1933,14 +1944,15 @@ static int blk_mq_init_hctx(struct request_queue *q,
 		goto sched_exit_hctx;
 
 	if (set->ops->init_request &&
-	    set->ops->init_request(set->driver_data,
-				   hctx->fq->flush_rq, hctx_idx,
-				   flush_start_tag + hctx_idx, node))
+	    set->ops->init_request(set, hctx->fq->flush_rq, hctx_idx,
+				   node))
 		goto free_fq;
 
 	if (hctx->flags & BLK_MQ_F_BLOCKING)
 		init_srcu_struct(&hctx->queue_rq_srcu);
 
+	blk_mq_debugfs_register_hctx(q, hctx);
+
 	return 0;
 
  free_fq:
@@ -2329,15 +2341,15 @@ struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
 
 	blk_mq_init_cpu_queues(q, set->nr_hw_queues);
 
-	get_online_cpus();
 	mutex_lock(&all_q_mutex);
+	get_online_cpus();
 
 	list_add_tail(&q->all_q_node, &all_q_list);
 	blk_mq_add_queue_tag_set(set, q);
 	blk_mq_map_swqueue(q, cpu_online_mask);
 
-	mutex_unlock(&all_q_mutex);
 	put_online_cpus();
+	mutex_unlock(&all_q_mutex);
 
 	if (!(set->flags & BLK_MQ_F_NO_SCHED)) {
 		int ret;
@@ -2378,6 +2390,7 @@ static void blk_mq_queue_reinit(struct request_queue *q,
 {
 	WARN_ON_ONCE(!atomic_read(&q->mq_freeze_depth));
 
+	blk_mq_debugfs_unregister_hctxs(q);
 	blk_mq_sysfs_unregister(q);
 
 	/*
@@ -2389,6 +2402,7 @@ static void blk_mq_queue_reinit(struct request_queue *q,
 	blk_mq_map_swqueue(q, online_mask);
 
 	blk_mq_sysfs_register(q);
+	blk_mq_debugfs_register_hctxs(q);
 }
 
 /*
@@ -2617,7 +2631,6 @@ int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr)
 		return -EINVAL;
 
 	blk_mq_freeze_queue(q);
-	blk_mq_quiesce_queue(q);
 
 	ret = 0;
 	queue_for_each_hw_ctx(q, hctx, i) {
@@ -2643,7 +2656,6 @@ int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr)
 		q->nr_requests = nr;
 
 	blk_mq_unfreeze_queue(q);
-	blk_mq_start_stopped_hw_queues(q, true);
 
 	return ret;
 }

block/blk-mq.h

@@ -83,34 +83,6 @@ extern int blk_mq_sysfs_register(struct request_queue *q);
 extern void blk_mq_sysfs_unregister(struct request_queue *q);
 extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
 
-/*
- * debugfs helpers
- */
-#ifdef CONFIG_BLK_DEBUG_FS
-int blk_mq_debugfs_register(struct request_queue *q);
-void blk_mq_debugfs_unregister(struct request_queue *q);
-int blk_mq_debugfs_register_mq(struct request_queue *q);
-void blk_mq_debugfs_unregister_mq(struct request_queue *q);
-#else
-static inline int blk_mq_debugfs_register(struct request_queue *q)
-{
-	return 0;
-}
-
-static inline void blk_mq_debugfs_unregister(struct request_queue *q)
-{
-}
-
-static inline int blk_mq_debugfs_register_mq(struct request_queue *q)
-{
-	return 0;
-}
-
-static inline void blk_mq_debugfs_unregister_mq(struct request_queue *q)
-{
-}
-#endif
-
 extern void blk_mq_rq_timed_out(struct request *req, bool reserved);
 
 void blk_mq_release(struct request_queue *q);

block/blk-sysfs.c

@@ -13,6 +13,7 @@
 
 #include "blk.h"
 #include "blk-mq.h"
+#include "blk-mq-debugfs.h"
 #include "blk-wbt.h"
 
 struct queue_sysfs_entry {
@@ -889,6 +890,8 @@ int blk_register_queue(struct gendisk *disk)
 	if (q->mq_ops)
 		__blk_mq_register_dev(dev, q);
 
+	blk_mq_debugfs_register(q);
+
 	kobject_uevent(&q->kobj, KOBJ_ADD);
 
 	wbt_enable_default(q);

block/elevator.c

@@ -950,7 +950,6 @@ static int elevator_switch_mq(struct request_queue *q,
 	int ret;
 
 	blk_mq_freeze_queue(q);
-	blk_mq_quiesce_queue(q);
 
 	if (q->elevator) {
 		if (q->elevator->registered)
@@ -978,9 +977,7 @@ static int elevator_switch_mq(struct request_queue *q,
 
 out:
 	blk_mq_unfreeze_queue(q);
-	blk_mq_start_stopped_hw_queues(q, true);
 	return ret;
-
 }
 
 /*
@@ -1088,19 +1085,6 @@ static int __elevator_change(struct request_queue *q, const char *name)
 	return elevator_switch(q, e);
 }
 
-int elevator_change(struct request_queue *q, const char *name)
-{
-	int ret;
-
-	/* Protect q->elevator from elevator_init() */
-	mutex_lock(&q->sysfs_lock);
-	ret = __elevator_change(q, name);
-	mutex_unlock(&q->sysfs_lock);
-
-	return ret;
-}
-EXPORT_SYMBOL(elevator_change);
-
 static inline bool elv_support_iosched(struct request_queue *q)
 {
 	if (q->mq_ops && q->tag_set && (q->tag_set->flags &

block/kyber-iosched.c

@@ -26,6 +26,7 @@
 
 #include "blk.h"
 #include "blk-mq.h"
+#include "blk-mq-debugfs.h"
 #include "blk-mq-sched.h"
 #include "blk-mq-tag.h"
 #include "blk-stat.h"
@@ -683,6 +684,131 @@ static struct elv_fs_entry kyber_sched_attrs[] = {
 };
 #undef KYBER_LAT_ATTR
 
+#ifdef CONFIG_BLK_DEBUG_FS
+#define KYBER_DEBUGFS_DOMAIN_ATTRS(domain, name)			\
+static int kyber_##name##_tokens_show(void *data, struct seq_file *m)	\
+{									\
+	struct request_queue *q = data;					\
+	struct kyber_queue_data *kqd = q->elevator->elevator_data;	\
+									\
+	sbitmap_queue_show(&kqd->domain_tokens[domain], m);		\
+	return 0;							\
+}									\
+									\
+static void *kyber_##name##_rqs_start(struct seq_file *m, loff_t *pos)	\
+	__acquires(&khd->lock)						\
+{									\
+	struct blk_mq_hw_ctx *hctx = m->private;			\
+	struct kyber_hctx_data *khd = hctx->sched_data;			\
+									\
+	spin_lock(&khd->lock);						\
+	return seq_list_start(&khd->rqs[domain], *pos);			\
+}									\
+									\
+static void *kyber_##name##_rqs_next(struct seq_file *m, void *v,	\
+				     loff_t *pos)			\
+{									\
+	struct blk_mq_hw_ctx *hctx = m->private;			\
+	struct kyber_hctx_data *khd = hctx->sched_data;			\
+									\
+	return seq_list_next(v, &khd->rqs[domain], pos);		\
+}									\
+									\
+static void kyber_##name##_rqs_stop(struct seq_file *m, void *v)	\
+	__releases(&khd->lock)						\
+{									\
+	struct blk_mq_hw_ctx *hctx = m->private;			\
+	struct kyber_hctx_data *khd = hctx->sched_data;			\
+									\
+	spin_unlock(&khd->lock);					\
+}									\
+									\
+static const struct seq_operations kyber_##name##_rqs_seq_ops = {	\
+	.start	= kyber_##name##_rqs_start,				\
+	.next	= kyber_##name##_rqs_next,				\
+	.stop	= kyber_##name##_rqs_stop,				\
+	.show	= blk_mq_debugfs_rq_show,				\
+};									\
+									\
+static int kyber_##name##_waiting_show(void *data, struct seq_file *m)	\
+{									\
+	struct blk_mq_hw_ctx *hctx = data;				\
+	struct kyber_hctx_data *khd = hctx->sched_data;			\
+	wait_queue_t *wait = &khd->domain_wait[domain];			\
+									\
+	seq_printf(m, "%d\n", !list_empty_careful(&wait->task_list));	\
+	return 0;							\
+}
+KYBER_DEBUGFS_DOMAIN_ATTRS(KYBER_READ, read)
+KYBER_DEBUGFS_DOMAIN_ATTRS(KYBER_SYNC_WRITE, sync_write)
+KYBER_DEBUGFS_DOMAIN_ATTRS(KYBER_OTHER, other)
+#undef KYBER_DEBUGFS_DOMAIN_ATTRS
+
+static int kyber_async_depth_show(void *data, struct seq_file *m)
+{
+	struct request_queue *q = data;
+	struct kyber_queue_data *kqd = q->elevator->elevator_data;
+
+	seq_printf(m, "%u\n", kqd->async_depth);
+	return 0;
+}
+
+static int kyber_cur_domain_show(void *data, struct seq_file *m)
+{
+	struct blk_mq_hw_ctx *hctx = data;
+	struct kyber_hctx_data *khd = hctx->sched_data;
+
+	switch (khd->cur_domain) {
+	case KYBER_READ:
+		seq_puts(m, "READ\n");
+		break;
+	case KYBER_SYNC_WRITE:
+		seq_puts(m, "SYNC_WRITE\n");
+		break;
+	case KYBER_OTHER:
+		seq_puts(m, "OTHER\n");
+		break;
+	default:
+		seq_printf(m, "%u\n", khd->cur_domain);
+		break;
+	}
+	return 0;
+}
+
+static int kyber_batching_show(void *data, struct seq_file *m)
+{
+	struct blk_mq_hw_ctx *hctx = data;
+	struct kyber_hctx_data *khd = hctx->sched_data;
+
+	seq_printf(m, "%u\n", khd->batching);
+	return 0;
+}
+
+#define KYBER_QUEUE_DOMAIN_ATTRS(name)	\
+	{#name "_tokens", 0400, kyber_##name##_tokens_show}
+static const struct blk_mq_debugfs_attr kyber_queue_debugfs_attrs[] = {
+	KYBER_QUEUE_DOMAIN_ATTRS(read),
+	KYBER_QUEUE_DOMAIN_ATTRS(sync_write),
+	KYBER_QUEUE_DOMAIN_ATTRS(other),
+	{"async_depth", 0400, kyber_async_depth_show},
+	{},
+};
+#undef KYBER_QUEUE_DOMAIN_ATTRS
+
+#define KYBER_HCTX_DOMAIN_ATTRS(name)					\
+	{#name "_rqs", 0400, .seq_ops = &kyber_##name##_rqs_seq_ops},	\
+	{#name "_waiting", 0400, kyber_##name##_waiting_show}
+static const struct blk_mq_debugfs_attr kyber_hctx_debugfs_attrs[] = {
+	KYBER_HCTX_DOMAIN_ATTRS(read),
+	KYBER_HCTX_DOMAIN_ATTRS(sync_write),
+	KYBER_HCTX_DOMAIN_ATTRS(other),
+	{"cur_domain", 0400, kyber_cur_domain_show},
+	{"batching", 0400, kyber_batching_show},
+	{},
+};
+#undef KYBER_HCTX_DOMAIN_ATTRS
+#endif
+
 static struct elevator_type kyber_sched = {
 	.ops.mq = {
 		.init_sched = kyber_init_sched,
@@ -696,6 +822,10 @@ static struct elevator_type kyber_sched = {
 		.has_work = kyber_has_work,
 	},
 	.uses_mq = true,
+#ifdef CONFIG_BLK_DEBUG_FS
+	.queue_debugfs_attrs = kyber_queue_debugfs_attrs,
+	.hctx_debugfs_attrs = kyber_hctx_debugfs_attrs,
+#endif
 	.elevator_attrs = kyber_sched_attrs,
 	.elevator_name = "kyber",
 	.elevator_owner = THIS_MODULE,

block/mq-deadline.c

@@ -19,6 +19,7 @@
 
 #include "blk.h"
 #include "blk-mq.h"
+#include "blk-mq-debugfs.h"
 #include "blk-mq-tag.h"
 #include "blk-mq-sched.h"
 
@@ -517,6 +518,125 @@ static struct elv_fs_entry deadline_attrs[] = {
 	__ATTR_NULL
 };
 
+#ifdef CONFIG_BLK_DEBUG_FS
+#define DEADLINE_DEBUGFS_DDIR_ATTRS(ddir, name)				\
+static void *deadline_##name##_fifo_start(struct seq_file *m,		\
+					  loff_t *pos)			\
+	__acquires(&dd->lock)						\
+{									\
+	struct request_queue *q = m->private;				\
+	struct deadline_data *dd = q->elevator->elevator_data;		\
+									\
+	spin_lock(&dd->lock);						\
+	return seq_list_start(&dd->fifo_list[ddir], *pos);		\
+}									\
+									\
+static void *deadline_##name##_fifo_next(struct seq_file *m, void *v,	\
+					 loff_t *pos)			\
+{									\
+	struct request_queue *q = m->private;				\
+	struct deadline_data *dd = q->elevator->elevator_data;		\
+									\
+	return seq_list_next(v, &dd->fifo_list[ddir], pos);		\
+}									\
+									\
+static void deadline_##name##_fifo_stop(struct seq_file *m, void *v)	\
+	__releases(&dd->lock)						\
+{									\
+	struct request_queue *q = m->private;				\
+	struct deadline_data *dd = q->elevator->elevator_data;		\
+									\
+	spin_unlock(&dd->lock);						\
+}									\
+									\
+static const struct seq_operations deadline_##name##_fifo_seq_ops = {	\
+	.start	= deadline_##name##_fifo_start,				\
+	.next	= deadline_##name##_fifo_next,				\
+	.stop	= deadline_##name##_fifo_stop,				\
+	.show	= blk_mq_debugfs_rq_show,				\
+};									\
+									\
+static int deadline_##name##_next_rq_show(void *data,			\
+					  struct seq_file *m)		\
+{									\
+	struct request_queue *q = data;					\
+	struct deadline_data *dd = q->elevator->elevator_data;		\
+	struct request *rq = dd->next_rq[ddir];				\
+									\
+	if (rq)								\
+		__blk_mq_debugfs_rq_show(m, rq);			\
+	return 0;							\
+}
+DEADLINE_DEBUGFS_DDIR_ATTRS(READ, read)
+DEADLINE_DEBUGFS_DDIR_ATTRS(WRITE, write)
+#undef DEADLINE_DEBUGFS_DDIR_ATTRS
+
+static int deadline_batching_show(void *data, struct seq_file *m)
+{
+	struct request_queue *q = data;
+	struct deadline_data *dd = q->elevator->elevator_data;
+
+	seq_printf(m, "%u\n", dd->batching);
+	return 0;
+}
+
+static int deadline_starved_show(void *data, struct seq_file *m)
+{
+	struct request_queue *q = data;
+	struct deadline_data *dd = q->elevator->elevator_data;
+
+	seq_printf(m, "%u\n", dd->starved);
+	return 0;
+}
+
+static void *deadline_dispatch_start(struct seq_file *m, loff_t *pos)
+	__acquires(&dd->lock)
+{
+	struct request_queue *q = m->private;
+	struct deadline_data *dd = q->elevator->elevator_data;
+
+	spin_lock(&dd->lock);
+	return seq_list_start(&dd->dispatch, *pos);
+}
+
+static void *deadline_dispatch_next(struct seq_file *m, void *v, loff_t *pos)
+{
+	struct request_queue *q = m->private;
+	struct deadline_data *dd = q->elevator->elevator_data;
+
+	return seq_list_next(v, &dd->dispatch, pos);
+}
+
+static void deadline_dispatch_stop(struct seq_file *m, void *v)
+	__releases(&dd->lock)
+{
+	struct request_queue *q = m->private;
+	struct deadline_data *dd = q->elevator->elevator_data;
+
+	spin_unlock(&dd->lock);
+}
+
+static const struct seq_operations deadline_dispatch_seq_ops = {
+	.start	= deadline_dispatch_start,
+	.next	= deadline_dispatch_next,
+	.stop	= deadline_dispatch_stop,
+	.show	= blk_mq_debugfs_rq_show,
+};
+
+#define DEADLINE_QUEUE_DDIR_ATTRS(name)						\
+	{#name "_fifo_list", 0400, .seq_ops = &deadline_##name##_fifo_seq_ops},	\
+	{#name "_next_rq", 0400, deadline_##name##_next_rq_show}
+static const struct blk_mq_debugfs_attr deadline_queue_debugfs_attrs[] = {
+	DEADLINE_QUEUE_DDIR_ATTRS(read),
+	DEADLINE_QUEUE_DDIR_ATTRS(write),
+	{"batching", 0400, deadline_batching_show},
+	{"starved", 0400, deadline_starved_show},
+	{"dispatch", 0400, .seq_ops = &deadline_dispatch_seq_ops},
+	{},
+};
+#undef DEADLINE_QUEUE_DDIR_ATTRS
+#endif
+
 static struct elevator_type mq_deadline = {
 	.ops.mq = {
 		.insert_requests	= dd_insert_requests,
@@ -533,6 +653,9 @@ static struct elevator_type mq_deadline = {
 	},
 
 	.uses_mq	= true,
+#ifdef CONFIG_BLK_DEBUG_FS
+	.queue_debugfs_attrs = deadline_queue_debugfs_attrs,
+#endif
 	.elevator_attrs = deadline_attrs,
 	.elevator_name = "mq-deadline",
 	.elevator_owner = THIS_MODULE,

drivers/block/loop.c

@@ -1697,9 +1697,8 @@ static void loop_queue_work(struct kthread_work *work)
 	loop_handle_cmd(cmd);
 }
 
-static int loop_init_request(void *data, struct request *rq,
-		unsigned int hctx_idx, unsigned int request_idx,
-		unsigned int numa_node)
+static int loop_init_request(struct blk_mq_tag_set *set, struct request *rq,
+		unsigned int hctx_idx, unsigned int numa_node)
 {
 	struct loop_cmd *cmd = blk_mq_rq_to_pdu(rq);
 

drivers/block/mtip32xx/mtip32xx.h

@@ -333,16 +333,6 @@ struct mtip_cmd {
 
 	dma_addr_t command_dma; /* corresponding physical address */
 
-	void *comp_data; /* data passed to completion function comp_func() */
-	/*
-	 * Completion function called by the ISR upon completion of
-	 * a command.
-	 */
-	void (*comp_func)(struct mtip_port *port,
-				int tag,
-				struct mtip_cmd *cmd,
-				int status);
-
 	int scatter_ents; /* Number of scatter list entries used */
 
 	int unaligned; /* command is unaligned on 4k boundary */

drivers/block/nbd.c

@@ -1396,12 +1396,11 @@ static void nbd_dbg_close(void)
 
 #endif
 
-static int nbd_init_request(void *data, struct request *rq,
-			    unsigned int hctx_idx, unsigned int request_idx,
-			    unsigned int numa_node)
+static int nbd_init_request(struct blk_mq_tag_set *set, struct request *rq,
+			    unsigned int hctx_idx, unsigned int numa_node)
 {
 	struct nbd_cmd *cmd = blk_mq_rq_to_pdu(rq);
-	cmd->nbd = data;
+	cmd->nbd = set->driver_data;
 	return 0;
 }
 

drivers/block/rbd.c

@@ -4307,9 +4307,8 @@ static int rbd_dev_refresh(struct rbd_device *rbd_dev)
 	return ret;
 }
 
-static int rbd_init_request(void *data, struct request *rq,
-		unsigned int hctx_idx, unsigned int request_idx,
-		unsigned int numa_node)
+static int rbd_init_request(struct blk_mq_tag_set *set, struct request *rq,
+		unsigned int hctx_idx, unsigned int numa_node)
 {
 	struct work_struct *work = blk_mq_rq_to_pdu(rq);
 

drivers/block/virtio_blk.c

@@ -573,11 +573,10 @@ static const struct device_attribute dev_attr_cache_type_rw =
 	__ATTR(cache_type, S_IRUGO|S_IWUSR,
 	       virtblk_cache_type_show, virtblk_cache_type_store);
 
-static int virtblk_init_request(void *data, struct request *rq,
-		unsigned int hctx_idx, unsigned int request_idx,
-		unsigned int numa_node)
+static int virtblk_init_request(struct blk_mq_tag_set *set, struct request *rq,
+		unsigned int hctx_idx, unsigned int numa_node)
 {
-	struct virtio_blk *vblk = data;
+	struct virtio_blk *vblk = set->driver_data;
 	struct virtblk_req *vbr = blk_mq_rq_to_pdu(rq);
 
 #ifdef CONFIG_VIRTIO_BLK_SCSI

drivers/lightnvm/core.c

@@ -74,7 +74,7 @@ static int nvm_reserve_luns(struct nvm_dev *dev, int lun_begin, int lun_end)
 
 	return 0;
 err:
-	while (--i > lun_begin)
+	while (--i >= lun_begin)
 		clear_bit(i, dev->lun_map);
 
 	return -EBUSY;
@@ -211,7 +211,7 @@ static struct nvm_tgt_dev *nvm_create_tgt_dev(struct nvm_dev *dev,
 
 	return tgt_dev;
 err_ch:
-	while (--i > 0)
+	while (--i >= 0)
 		kfree(dev_map->chnls[i].lun_offs);
 	kfree(luns);
 err_luns:

drivers/md/dm-rq.c

@@ -720,11 +720,10 @@ int dm_old_init_request_queue(struct mapped_device *md, struct dm_table *t)
 	return 0;
 }
 
-static int dm_mq_init_request(void *data, struct request *rq,
-		       unsigned int hctx_idx, unsigned int request_idx,
-		       unsigned int numa_node)
+static int dm_mq_init_request(struct blk_mq_tag_set *set, struct request *rq,
+		unsigned int hctx_idx, unsigned int numa_node)
 {
-	return __dm_rq_init_rq(data, rq);
+	return __dm_rq_init_rq(set->driver_data, rq);
 }
 
 static int dm_mq_queue_rq(struct blk_mq_hw_ctx *hctx,

drivers/mtd/ubi/block.c

@@ -334,10 +334,9 @@ static int ubiblock_queue_rq(struct blk_mq_hw_ctx *hctx,
 
 }
 
-static int ubiblock_init_request(void *data, struct request *req,
-				 unsigned int hctx_idx,
-				 unsigned int request_idx,
-				 unsigned int numa_node)
+static int ubiblock_init_request(struct blk_mq_tag_set *set,
+		struct request *req, unsigned int hctx_idx,
+		unsigned int numa_node)
 {
 	struct ubiblock_pdu *pdu = blk_mq_rq_to_pdu(req);