1 files changed, 680 insertions, 207 deletions

diff --git a/block/mq-deadline.c b/block/mq-deadline.c
index b490f47fd553..f958e79277b8 100644
--- a/block/mq-deadline.c
+++ b/block/mq-deadline.c
@@ -8,8 +8,6 @@
 #include <linux/kernel.h>
 #include <linux/fs.h>
 #include <linux/blkdev.h>
-#include <linux/blk-mq.h>
-#include <linux/elevator.h>
 #include <linux/bio.h>
 #include <linux/module.h>
 #include <linux/slab.h>
@@ -18,10 +16,12 @@
 #include <linux/rbtree.h>
 #include <linux/sbitmap.h>
 
+#include <trace/events/block.h>
+
+#include "elevator.h"
 #include "blk.h"
 #include "blk-mq.h"
 #include "blk-mq-debugfs.h"
-#include "blk-mq-tag.h"
 #include "blk-mq-sched.h"
 
 /*
@@ -29,45 +29,117 @@
  */
 static const int read_expire = HZ / 2;  /* max time before a read is submitted. */
 static const int write_expire = 5 * HZ; /* ditto for writes, these limits are SOFT! */
+/*
+ * Time after which to dispatch lower priority requests even if higher
+ * priority requests are pending.
+ */
+static const int prio_aging_expire = 10 * HZ;
 static const int writes_starved = 2;    /* max times reads can starve a write */
 static const int fifo_batch = 16;       /* # of sequential requests treated as one
 				     by the above parameters. For throughput. */
 
+enum dd_data_dir {
+	DD_READ		= READ,
+	DD_WRITE	= WRITE,
+};
+
+enum { DD_DIR_COUNT = 2 };
+
+enum dd_prio {
+	DD_RT_PRIO	= 0,
+	DD_BE_PRIO	= 1,
+	DD_IDLE_PRIO	= 2,
+	DD_PRIO_MAX	= 2,
+};
+
+enum { DD_PRIO_COUNT = 3 };
+
+/*
+ * I/O statistics per I/O priority. It is fine if these counters overflow.
+ * What matters is that these counters are at least as wide as
+ * log2(max_outstanding_requests).
+ */
+struct io_stats_per_prio {
+	uint32_t inserted;
+	uint32_t merged;
+	uint32_t dispatched;
+	atomic_t completed;
+};
+
+/*
+ * Deadline scheduler data per I/O priority (enum dd_prio). Requests are
+ * present on both sort_list[] and fifo_list[].
+ */
+struct dd_per_prio {
+	struct list_head dispatch;
+	struct rb_root sort_list[DD_DIR_COUNT];
+	struct list_head fifo_list[DD_DIR_COUNT];
+	/* Position of the most recently dispatched request. */
+	sector_t latest_pos[DD_DIR_COUNT];
+	struct io_stats_per_prio stats;
+};
+
 struct deadline_data {
 	/*
 	 * run time data
 	 */
 
-	/*
-	 * requests (deadline_rq s) are present on both sort_list and fifo_list
-	 */
-	struct rb_root sort_list[2];
-	struct list_head fifo_list[2];
+	struct dd_per_prio per_prio[DD_PRIO_COUNT];
 
-	/*
-	 * next in sort order. read, write or both are NULL
-	 */
-	struct request *next_rq[2];
+	/* Data direction of latest dispatched request. */
+	enum dd_data_dir last_dir;
 	unsigned int batching;		/* number of sequential requests made */
 	unsigned int starved;		/* times reads have starved writes */
 
 	/*
 	 * settings that change how the i/o scheduler behaves
 	 */
-	int fifo_expire[2];
+	int fifo_expire[DD_DIR_COUNT];
 	int fifo_batch;
 	int writes_starved;
 	int front_merges;
+	u32 async_depth;
+	int prio_aging_expire;
 
 	spinlock_t lock;
 	spinlock_t zone_lock;
-	struct list_head dispatch;
+};
+
+/* Maps an I/O priority class to a deadline scheduler priority. */
+static const enum dd_prio ioprio_class_to_prio[] = {
+	[IOPRIO_CLASS_NONE]	= DD_BE_PRIO,
+	[IOPRIO_CLASS_RT]	= DD_RT_PRIO,
+	[IOPRIO_CLASS_BE]	= DD_BE_PRIO,
+	[IOPRIO_CLASS_IDLE]	= DD_IDLE_PRIO,
 };
 
 static inline struct rb_root *
-deadline_rb_root(struct deadline_data *dd, struct request *rq)
+deadline_rb_root(struct dd_per_prio *per_prio, struct request *rq)
 {
-	return &dd->sort_list[rq_data_dir(rq)];
+	return &per_prio->sort_list[rq_data_dir(rq)];
+}
+
+/*
+ * Returns the I/O priority class (IOPRIO_CLASS_*) that has been assigned to a
+ * request.
+ */
+static u8 dd_rq_ioclass(struct request *rq)
+{
+	return IOPRIO_PRIO_CLASS(req_get_ioprio(rq));
+}
+
+/*
+ * get the request before `rq' in sector-sorted order
+ */
+static inline struct request *
+deadline_earlier_request(struct request *rq)
+{
+	struct rb_node *node = rb_prev(&rq->rb_node);
+
+	if (node)
+		return rb_entry_rq(node);
+
+	return NULL;
 }
 
 /*
@@ -84,39 +156,68 @@ deadline_latter_request(struct request *rq)
 	return NULL;
 }
 
+/*
+ * Return the first request for which blk_rq_pos() >= @pos. For zoned devices,
+ * return the first request after the start of the zone containing @pos.
+ */
+static inline struct request *deadline_from_pos(struct dd_per_prio *per_prio,
+				enum dd_data_dir data_dir, sector_t pos)
+{
+	struct rb_node *node = per_prio->sort_list[data_dir].rb_node;
+	struct request *rq, *res = NULL;
+
+	if (!node)
+		return NULL;
+
+	rq = rb_entry_rq(node);
+	/*
+	 * A zoned write may have been requeued with a starting position that
+	 * is below that of the most recently dispatched request. Hence, for
+	 * zoned writes, start searching from the start of a zone.
+	 */
+	if (blk_rq_is_seq_zoned_write(rq))
+		pos = round_down(pos, rq->q->limits.chunk_sectors);
+
+	while (node) {
+		rq = rb_entry_rq(node);
+		if (blk_rq_pos(rq) >= pos) {
+			res = rq;
+			node = node->rb_left;
+		} else {
+			node = node->rb_right;
+		}
+	}
+	return res;
+}
+
 static void
-deadline_add_rq_rb(struct deadline_data *dd, struct request *rq)
+deadline_add_rq_rb(struct dd_per_prio *per_prio, struct request *rq)
 {
-	struct rb_root *root = deadline_rb_root(dd, rq);
+	struct rb_root *root = deadline_rb_root(per_prio, rq);
 
 	elv_rb_add(root, rq);
 }
 
 static inline void
-deadline_del_rq_rb(struct deadline_data *dd, struct request *rq)
+deadline_del_rq_rb(struct dd_per_prio *per_prio, struct request *rq)
 {
-	const int data_dir = rq_data_dir(rq);
-
-	if (dd->next_rq[data_dir] == rq)
-		dd->next_rq[data_dir] = deadline_latter_request(rq);
-
-	elv_rb_del(deadline_rb_root(dd, rq), rq);
+	elv_rb_del(deadline_rb_root(per_prio, rq), rq);
 }
 
 /*
  * remove rq from rbtree and fifo.
  */
-static void deadline_remove_request(struct request_queue *q, struct request *rq)
+static void deadline_remove_request(struct request_queue *q,
+				    struct dd_per_prio *per_prio,
+				    struct request *rq)
 {
-	struct deadline_data *dd = q->elevator->elevator_data;
-
 	list_del_init(&rq->queuelist);
 
 	/*
 	 * We might not be on the rbtree, if we are doing an insert merge
 	 */
 	if (!RB_EMPTY_NODE(&rq->rb_node))
-		deadline_del_rq_rb(dd, rq);
+		deadline_del_rq_rb(per_prio, rq);
 
 	elv_rqhash_del(q, rq);
 	if (q->last_merge == rq)
@@ -127,19 +228,33 @@ static void dd_request_merged(struct request_queue *q, struct request *req,
 			      enum elv_merge type)
 {
 	struct deadline_data *dd = q->elevator->elevator_data;
+	const u8 ioprio_class = dd_rq_ioclass(req);
+	const enum dd_prio prio = ioprio_class_to_prio[ioprio_class];
+	struct dd_per_prio *per_prio = &dd->per_prio[prio];
 
 	/*
 	 * if the merge was a front merge, we need to reposition request
 	 */
 	if (type == ELEVATOR_FRONT_MERGE) {
-		elv_rb_del(deadline_rb_root(dd, req), req);
-		deadline_add_rq_rb(dd, req);
+		elv_rb_del(deadline_rb_root(per_prio, req), req);
+		deadline_add_rq_rb(per_prio, req);
 	}
 }
 
+/*
+ * Callback function that is invoked after @next has been merged into @req.
+ */
 static void dd_merged_requests(struct request_queue *q, struct request *req,
 			       struct request *next)
 {
+	struct deadline_data *dd = q->elevator->elevator_data;
+	const u8 ioprio_class = dd_rq_ioclass(next);
+	const enum dd_prio prio = ioprio_class_to_prio[ioprio_class];
+
+	lockdep_assert_held(&dd->lock);
+
+	dd->per_prio[prio].stats.merged++;
+
 	/*
 	 * if next expires before rq, assign its expire time to rq
 	 * and move into next position (next will be deleted) in fifo
@@ -155,42 +270,72 @@ static void dd_merged_requests(struct request_queue *q, struct request *req,
 	/*
 	 * kill knowledge of next, this one is a goner
 	 */
-	deadline_remove_request(q, next);
+	deadline_remove_request(q, &dd->per_prio[prio], next);
 }
 
 /*
  * move an entry to dispatch queue
  */
 static void
-deadline_move_request(struct deadline_data *dd, struct request *rq)
+deadline_move_request(struct deadline_data *dd, struct dd_per_prio *per_prio,
+		      struct request *rq)
 {
-	const int data_dir = rq_data_dir(rq);
-
-	dd->next_rq[READ] = NULL;
-	dd->next_rq[WRITE] = NULL;
-	dd->next_rq[data_dir] = deadline_latter_request(rq);
-
 	/*
 	 * take it off the sort and fifo list
 	 */
-	deadline_remove_request(rq->q, rq);
+	deadline_remove_request(rq->q, per_prio, rq);
+}
+
+/* Number of requests queued for a given priority level. */
+static u32 dd_queued(struct deadline_data *dd, enum dd_prio prio)
+{
+	const struct io_stats_per_prio *stats = &dd->per_prio[prio].stats;
+
+	lockdep_assert_held(&dd->lock);
+
+	return stats->inserted - atomic_read(&stats->completed);
 }
 
 /*
- * deadline_check_fifo returns 0 if there are no expired requests on the fifo,
- * 1 otherwise. Requires !list_empty(&dd->fifo_list[data_dir])
+ * deadline_check_fifo returns true if and only if there are expired requests
+ * in the FIFO list. Requires !list_empty(&dd->fifo_list[data_dir]).
  */
-static inline int deadline_check_fifo(struct deadline_data *dd, int ddir)
+static inline bool deadline_check_fifo(struct dd_per_prio *per_prio,
+				       enum dd_data_dir data_dir)
 {
-	struct request *rq = rq_entry_fifo(dd->fifo_list[ddir].next);
+	struct request *rq = rq_entry_fifo(per_prio->fifo_list[data_dir].next);
 
-	/*
-	 * rq is expired!
-	 */
-	if (time_after_eq(jiffies, (unsigned long)rq->fifo_time))
-		return 1;
+	return time_is_before_eq_jiffies((unsigned long)rq->fifo_time);
+}
 
-	return 0;
+/*
+ * Check if rq has a sequential request preceding it.
+ */
+static bool deadline_is_seq_write(struct deadline_data *dd, struct request *rq)
+{
+	struct request *prev = deadline_earlier_request(rq);
+
+	if (!prev)
+		return false;
+
+	return blk_rq_pos(prev) + blk_rq_sectors(prev) == blk_rq_pos(rq);
+}
+
+/*
+ * Skip all write requests that are sequential from @rq, even if we cross
+ * a zone boundary.
+ */
+static struct request *deadline_skip_seq_writes(struct deadline_data *dd,
+						struct request *rq)
+{
+	sector_t pos = blk_rq_pos(rq);
+
+	do {
+		pos += blk_rq_sectors(rq);
+		rq = deadline_latter_request(rq);
+	} while (rq && blk_rq_pos(rq) == pos);
+
+	return rq;
 }
 
 /*
@@ -198,28 +343,36 @@ static inline int deadline_check_fifo(struct deadline_data *dd, int ddir)
  * dispatch using arrival ordered lists.
  */
 static struct request *
-deadline_fifo_request(struct deadline_data *dd, int data_dir)
+deadline_fifo_request(struct deadline_data *dd, struct dd_per_prio *per_prio,
+		      enum dd_data_dir data_dir)
 {
-	struct request *rq;
+	struct request *rq, *rb_rq, *next;
 	unsigned long flags;
 
-	if (WARN_ON_ONCE(data_dir != READ && data_dir != WRITE))
-		return NULL;
-
-	if (list_empty(&dd->fifo_list[data_dir]))
+	if (list_empty(&per_prio->fifo_list[data_dir]))
 		return NULL;
 
-	rq = rq_entry_fifo(dd->fifo_list[data_dir].next);
-	if (data_dir == READ || !blk_queue_is_zoned(rq->q))
+	rq = rq_entry_fifo(per_prio->fifo_list[data_dir].next);
+	if (data_dir == DD_READ || !blk_queue_is_zoned(rq->q))
 		return rq;
 
 	/*
 	 * Look for a write request that can be dispatched, that is one with
-	 * an unlocked target zone.
+	 * an unlocked target zone. For some HDDs, breaking a sequential
+	 * write stream can lead to lower throughput, so make sure to preserve
+	 * sequential write streams, even if that stream crosses into the next
+	 * zones and these zones are unlocked.
 	 */
 	spin_lock_irqsave(&dd->zone_lock, flags);
-	list_for_each_entry(rq, &dd->fifo_list[WRITE], queuelist) {
-		if (blk_req_can_dispatch_to_zone(rq))
+	list_for_each_entry_safe(rq, next, &per_prio->fifo_list[DD_WRITE],
+				 queuelist) {
+		/* Check whether a prior request exists for the same zone. */
+		rb_rq = deadline_from_pos(per_prio, data_dir, blk_rq_pos(rq));
+		if (rb_rq && blk_rq_pos(rb_rq) < blk_rq_pos(rq))
+			rq = rb_rq;
+		if (blk_req_can_dispatch_to_zone(rq) &&
+		    (blk_queue_nonrot(rq->q) ||
+		     !deadline_is_seq_write(dd, rq)))
 			goto out;
 	}
 	rq = NULL;
@@ -234,30 +387,35 @@ out:
  * dispatch using sector position sorted lists.
  */
 static struct request *
-deadline_next_request(struct deadline_data *dd, int data_dir)
+deadline_next_request(struct deadline_data *dd, struct dd_per_prio *per_prio,
+		      enum dd_data_dir data_dir)
 {
 	struct request *rq;
 	unsigned long flags;
 
-	if (WARN_ON_ONCE(data_dir != READ && data_dir != WRITE))
-		return NULL;
-
-	rq = dd->next_rq[data_dir];
+	rq = deadline_from_pos(per_prio, data_dir,
+			       per_prio->latest_pos[data_dir]);
 	if (!rq)
 		return NULL;
 
-	if (data_dir == READ || !blk_queue_is_zoned(rq->q))
+	if (data_dir == DD_READ || !blk_queue_is_zoned(rq->q))
 		return rq;
 
 	/*
 	 * Look for a write request that can be dispatched, that is one with
-	 * an unlocked target zone.
+	 * an unlocked target zone. For some HDDs, breaking a sequential
+	 * write stream can lead to lower throughput, so make sure to preserve
+	 * sequential write streams, even if that stream crosses into the next
+	 * zones and these zones are unlocked.
 	 */
 	spin_lock_irqsave(&dd->zone_lock, flags);
 	while (rq) {
 		if (blk_req_can_dispatch_to_zone(rq))
 			break;
-		rq = deadline_latter_request(rq);
+		if (blk_queue_nonrot(rq->q))
+			rq = deadline_latter_request(rq);
+		else
+			rq = deadline_skip_seq_writes(dd, rq);
 	}
 	spin_unlock_irqrestore(&dd->zone_lock, flags);
 
@@ -265,48 +423,67 @@ deadline_next_request(struct deadline_data *dd, int data_dir)
 }
 
 /*
+ * Returns true if and only if @rq started after @latest_start where
+ * @latest_start is in jiffies.
+ */
+static bool started_after(struct deadline_data *dd, struct request *rq,
+			  unsigned long latest_start)
+{
+	unsigned long start_time = (unsigned long)rq->fifo_time;
+
+	start_time -= dd->fifo_expire[rq_data_dir(rq)];
+
+	return time_after(start_time, latest_start);
+}
+
+/*
  * deadline_dispatch_requests selects the best request according to
- * read/write expire, fifo_batch, etc
+ * read/write expire, fifo_batch, etc and with a start time <= @latest_start.
  */
-static struct request *__dd_dispatch_request(struct deadline_data *dd)
+static struct request *__dd_dispatch_request(struct deadline_data *dd,
+					     struct dd_per_prio *per_prio,
+					     unsigned long latest_start)
 {
 	struct request *rq, *next_rq;
-	bool reads, writes;
-	int data_dir;
+	enum dd_data_dir data_dir;
+	enum dd_prio prio;
+	u8 ioprio_class;
+
+	lockdep_assert_held(&dd->lock);
 
-	if (!list_empty(&dd->dispatch)) {
-		rq = list_first_entry(&dd->dispatch, struct request, queuelist);
+	if (!list_empty(&per_prio->dispatch)) {
+		rq = list_first_entry(&per_prio->dispatch, struct request,
+				      queuelist);
+		if (started_after(dd, rq, latest_start))
+			return NULL;
 		list_del_init(&rq->queuelist);
+		data_dir = rq_data_dir(rq);
 		goto done;
 	}
 
-	reads = !list_empty(&dd->fifo_list[READ]);
-	writes = !list_empty(&dd->fifo_list[WRITE]);
-
 	/*
 	 * batches are currently reads XOR writes
 	 */
-	rq = deadline_next_request(dd, WRITE);
-	if (!rq)
-		rq = deadline_next_request(dd, READ);
-
-	if (rq && dd->batching < dd->fifo_batch)
-		/* we have a next request are still entitled to batch */
+	rq = deadline_next_request(dd, per_prio, dd->last_dir);
+	if (rq && dd->batching < dd->fifo_batch) {
+		/* we have a next request and are still entitled to batch */
+		data_dir = rq_data_dir(rq);
 		goto dispatch_request;
+	}
 
 	/*
 	 * at this point we are not running a batch. select the appropriate
 	 * data direction (read / write)
 	 */
 
-	if (reads) {
-		BUG_ON(RB_EMPTY_ROOT(&dd->sort_list[READ]));
+	if (!list_empty(&per_prio->fifo_list[DD_READ])) {
+		BUG_ON(RB_EMPTY_ROOT(&per_prio->sort_list[DD_READ]));
 
-		if (deadline_fifo_request(dd, WRITE) &&
+		if (deadline_fifo_request(dd, per_prio, DD_WRITE) &&
 		    (dd->starved++ >= dd->writes_starved))
 			goto dispatch_writes;
 
-		data_dir = READ;
+		data_dir = DD_READ;
 
 		goto dispatch_find_request;
 	}
@@ -315,13 +492,13 @@ static struct request *__dd_dispatch_request(struct deadline_data *dd)
 	 * there are either no reads or writes have been starved
 	 */
 
-	if (writes) {
+	if (!list_empty(&per_prio->fifo_list[DD_WRITE])) {
 dispatch_writes:
-		BUG_ON(RB_EMPTY_ROOT(&dd->sort_list[WRITE]));
+		BUG_ON(RB_EMPTY_ROOT(&per_prio->sort_list[DD_WRITE]));
 
 		dd->starved = 0;
 
-		data_dir = WRITE;
+		data_dir = DD_WRITE;
 
 		goto dispatch_find_request;
 	}
@@ -332,14 +509,14 @@ dispatch_find_request:
 	/*
 	 * we are not running a batch, find best request for selected data_dir
 	 */
-	next_rq = deadline_next_request(dd, data_dir);
-	if (deadline_check_fifo(dd, data_dir) || !next_rq) {
+	next_rq = deadline_next_request(dd, per_prio, data_dir);
+	if (deadline_check_fifo(per_prio, data_dir) || !next_rq) {
 		/*
 		 * A deadline has expired, the last request was in the other
 		 * direction, or we have run out of higher-sectored requests.
 		 * Start again from the request with the earliest expiry time.
 		 */
-		rq = deadline_fifo_request(dd, data_dir);
+		rq = deadline_fifo_request(dd, per_prio, data_dir);
 	} else {
 		/*
 		 * The last req was the same dir and we have a next request in
@@ -355,15 +532,23 @@ dispatch_find_request:
 	if (!rq)
 		return NULL;
 
+	dd->last_dir = data_dir;
 	dd->batching = 0;
 
 dispatch_request:
+	if (started_after(dd, rq, latest_start))
+		return NULL;
+
 	/*
 	 * rq is the selected appropriate request.
 	 */
 	dd->batching++;
-	deadline_move_request(dd, rq);
+	deadline_move_request(dd, per_prio, rq);
 done:
+	ioprio_class = dd_rq_ioclass(rq);
+	prio = ioprio_class_to_prio[ioprio_class];
+	dd->per_prio[prio].latest_pos[data_dir] = blk_rq_pos(rq);
+	dd->per_prio[prio].stats.dispatched++;
 	/*
 	 * If the request needs its target zone locked, do it.
 	 */
@@ -373,6 +558,36 @@ done:
 }
 
 /*
+ * Check whether there are any requests with priority other than DD_RT_PRIO
+ * that were inserted more than prio_aging_expire jiffies ago.
+ */
+static struct request *dd_dispatch_prio_aged_requests(struct deadline_data *dd,
+						      unsigned long now)
+{
+	struct request *rq;
+	enum dd_prio prio;
+	int prio_cnt;
+
+	lockdep_assert_held(&dd->lock);
+
+	prio_cnt = !!dd_queued(dd, DD_RT_PRIO) + !!dd_queued(dd, DD_BE_PRIO) +
+		   !!dd_queued(dd, DD_IDLE_PRIO);
+	if (prio_cnt < 2)
+		return NULL;
+
+	for (prio = DD_BE_PRIO; prio <= DD_PRIO_MAX; prio++) {
+		rq = __dd_dispatch_request(dd, &dd->per_prio[prio],
+					   now - dd->prio_aging_expire);
+		if (rq)
+			return rq;
+	}
+
+	return NULL;
+}
+
+/*
+ * Called from blk_mq_run_hw_queue() -> __blk_mq_sched_dispatch_requests().
+ *
  * One confusing aspect here is that we get called for a specific
  * hardware queue, but we may return a request that is for a
  * different hardware queue. This is because mq-deadline has shared
@@ -381,21 +596,92 @@ done:
 static struct request *dd_dispatch_request(struct blk_mq_hw_ctx *hctx)
 {
 	struct deadline_data *dd = hctx->queue->elevator->elevator_data;
+	const unsigned long now = jiffies;
 	struct request *rq;
+	enum dd_prio prio;
 
 	spin_lock(&dd->lock);
-	rq = __dd_dispatch_request(dd);
+	rq = dd_dispatch_prio_aged_requests(dd, now);
+	if (rq)
+		goto unlock;
+
+	/*
+	 * Next, dispatch requests in priority order. Ignore lower priority
+	 * requests if any higher priority requests are pending.
+	 */
+	for (prio = 0; prio <= DD_PRIO_MAX; prio++) {
+		rq = __dd_dispatch_request(dd, &dd->per_prio[prio], now);
+		if (rq || dd_queued(dd, prio))
+			break;
+	}
+
+unlock:
 	spin_unlock(&dd->lock);
 
 	return rq;
 }
 
-static void dd_exit_queue(struct elevator_queue *e)
+/*
+ * Called by __blk_mq_alloc_request(). The shallow_depth value set by this
+ * function is used by __blk_mq_get_tag().
+ */
+static void dd_limit_depth(blk_opf_t opf, struct blk_mq_alloc_data *data)
+{
+	struct deadline_data *dd = data->q->elevator->elevator_data;
+
+	/* Do not throttle synchronous reads. */
+	if (op_is_sync(opf) && !op_is_write(opf))
+		return;
+
+	/*
+	 * Throttle asynchronous requests and writes such that these requests
+	 * do not block the allocation of synchronous requests.
+	 */
+	data->shallow_depth = dd->async_depth;
+}
+
+/* Called by blk_mq_update_nr_requests(). */
+static void dd_depth_updated(struct blk_mq_hw_ctx *hctx)
+{
+	struct request_queue *q = hctx->queue;
+	struct deadline_data *dd = q->elevator->elevator_data;
+	struct blk_mq_tags *tags = hctx->sched_tags;
+	unsigned int shift = tags->bitmap_tags.sb.shift;
+
+	dd->async_depth = max(1U, 3 * (1U << shift)  / 4);
+
+	sbitmap_queue_min_shallow_depth(&tags->bitmap_tags, dd->async_depth);
+}
+
+/* Called by blk_mq_init_hctx() and blk_mq_init_sched(). */
+static int dd_init_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx)
+{
+	dd_depth_updated(hctx);
+	return 0;
+}
+
+static void dd_exit_sched(struct elevator_queue *e)
 {
 	struct deadline_data *dd = e->elevator_data;
+	enum dd_prio prio;
 
-	BUG_ON(!list_empty(&dd->fifo_list[READ]));
-	BUG_ON(!list_empty(&dd->fifo_list[WRITE]));
+	for (prio = 0; prio <= DD_PRIO_MAX; prio++) {
+		struct dd_per_prio *per_prio = &dd->per_prio[prio];
+		const struct io_stats_per_prio *stats = &per_prio->stats;
+		uint32_t queued;
+
+		WARN_ON_ONCE(!list_empty(&per_prio->fifo_list[DD_READ]));
+		WARN_ON_ONCE(!list_empty(&per_prio->fifo_list[DD_WRITE]));
+
+		spin_lock(&dd->lock);
+		queued = dd_queued(dd, prio);
+		spin_unlock(&dd->lock);
+
+		WARN_ONCE(queued != 0,
+			  "statistics for priority %d: i %u m %u d %u c %u\n",
+			  prio, stats->inserted, stats->merged,
+			  stats->dispatched, atomic_read(&stats->completed));
+	}
 
 	kfree(dd);
 }
@@ -403,55 +689,78 @@ static void dd_exit_queue(struct elevator_queue *e)
 /*
  * initialize elevator private data (deadline_data).
  */
-static int dd_init_queue(struct request_queue *q, struct elevator_type *e)
+static int dd_init_sched(struct request_queue *q, struct elevator_type *e)
 {
 	struct deadline_data *dd;
 	struct elevator_queue *eq;
+	enum dd_prio prio;
+	int ret = -ENOMEM;
 
 	eq = elevator_alloc(q, e);
 	if (!eq)
-		return -ENOMEM;
+		return ret;
 
 	dd = kzalloc_node(sizeof(*dd), GFP_KERNEL, q->node);
-	if (!dd) {
-		kobject_put(&eq->kobj);
-		return -ENOMEM;
-	}
+	if (!dd)
+		goto put_eq;
+
 	eq->elevator_data = dd;
 
-	INIT_LIST_HEAD(&dd->fifo_list[READ]);
-	INIT_LIST_HEAD(&dd->fifo_list[WRITE]);
-	dd->sort_list[READ] = RB_ROOT;
-	dd->sort_list[WRITE] = RB_ROOT;
-	dd->fifo_expire[READ] = read_expire;
-	dd->fifo_expire[WRITE] = write_expire;
+	for (prio = 0; prio <= DD_PRIO_MAX; prio++) {
+		struct dd_per_prio *per_prio = &dd->per_prio[prio];
+
+		INIT_LIST_HEAD(&per_prio->dispatch);
+		INIT_LIST_HEAD(&per_prio->fifo_list[DD_READ]);
+		INIT_LIST_HEAD(&per_prio->fifo_list[DD_WRITE]);
+		per_prio->sort_list[DD_READ] = RB_ROOT;
+		per_prio->sort_list[DD_WRITE] = RB_ROOT;
+	}
+	dd->fifo_expire[DD_READ] = read_expire;
+	dd->fifo_expire[DD_WRITE] = write_expire;
 	dd->writes_starved = writes_starved;
 	dd->front_merges = 1;
+	dd->last_dir = DD_WRITE;
 	dd->fifo_batch = fifo_batch;
+	dd->prio_aging_expire = prio_aging_expire;
 	spin_lock_init(&dd->lock);
 	spin_lock_init(&dd->zone_lock);
-	INIT_LIST_HEAD(&dd->dispatch);
+
+	/* We dispatch from request queue wide instead of hw queue */
+	blk_queue_flag_set(QUEUE_FLAG_SQ_SCHED, q);
 
 	q->elevator = eq;
 	return 0;
+
+put_eq:
+	kobject_put(&eq->kobj);
+	return ret;
 }
 
+/*
+ * Try to merge @bio into an existing request. If @bio has been merged into
+ * an existing request, store the pointer to that request into *@rq.
+ */
 static int dd_request_merge(struct request_queue *q, struct request **rq,
 			    struct bio *bio)
 {
 	struct deadline_data *dd = q->elevator->elevator_data;
+	const u8 ioprio_class = IOPRIO_PRIO_CLASS(bio->bi_ioprio);
+	const enum dd_prio prio = ioprio_class_to_prio[ioprio_class];
+	struct dd_per_prio *per_prio = &dd->per_prio[prio];
 	sector_t sector = bio_end_sector(bio);
 	struct request *__rq;
 
 	if (!dd->front_merges)
 		return ELEVATOR_NO_MERGE;
 
-	__rq = elv_rb_find(&dd->sort_list[bio_data_dir(bio)], sector);
+	__rq = elv_rb_find(&per_prio->sort_list[bio_data_dir(bio)], sector);
 	if (__rq) {
 		BUG_ON(sector != blk_rq_pos(__rq));
 
 		if (elv_bio_merge_ok(__rq, bio)) {
 			*rq = __rq;
+			if (blk_discard_mergable(__rq))
+				return ELEVATOR_DISCARD_MERGE;
 			return ELEVATOR_FRONT_MERGE;
 		}
 	}
@@ -459,10 +768,13 @@ static int dd_request_merge(struct request_queue *q, struct request **rq,
 	return ELEVATOR_NO_MERGE;
 }
 
-static bool dd_bio_merge(struct blk_mq_hw_ctx *hctx, struct bio *bio,
+/*
+ * Attempt to merge a bio into an existing request. This function is called
+ * before @bio is associated with a request.
+ */
+static bool dd_bio_merge(struct request_queue *q, struct bio *bio,
 		unsigned int nr_segs)
 {
-	struct request_queue *q = hctx->queue;
 	struct deadline_data *dd = q->elevator->elevator_data;
 	struct request *free = NULL;
 	bool ret;
@@ -481,11 +793,17 @@ static bool dd_bio_merge(struct blk_mq_hw_ctx *hctx, struct bio *bio,
  * add rq to rbtree and fifo
  */
 static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
-			      bool at_head)
+			      blk_insert_t flags, struct list_head *free)
 {
 	struct request_queue *q = hctx->queue;
 	struct deadline_data *dd = q->elevator->elevator_data;
-	const int data_dir = rq_data_dir(rq);
+	const enum dd_data_dir data_dir = rq_data_dir(rq);
+	u16 ioprio = req_get_ioprio(rq);
+	u8 ioprio_class = IOPRIO_PRIO_CLASS(ioprio);
+	struct dd_per_prio *per_prio;
+	enum dd_prio prio;
+
+	lockdep_assert_held(&dd->lock);
 
 	/*
 	 * This may be a requeue of a write request that has locked its
@@ -493,18 +811,25 @@ static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
 	 */
 	blk_req_zone_write_unlock(rq);
 
-	if (blk_mq_sched_try_insert_merge(q, rq))
+	prio = ioprio_class_to_prio[ioprio_class];
+	per_prio = &dd->per_prio[prio];
+	if (!rq->elv.priv[0]) {
+		per_prio->stats.inserted++;
+		rq->elv.priv[0] = (void *)(uintptr_t)1;
+	}
+
+	if (blk_mq_sched_try_insert_merge(q, rq, free))
 		return;
 
-	blk_mq_sched_request_inserted(rq);
+	trace_block_rq_insert(rq);
 
-	if (at_head || blk_rq_is_passthrough(rq)) {
-		if (at_head)
-			list_add(&rq->queuelist, &dd->dispatch);
-		else
-			list_add_tail(&rq->queuelist, &dd->dispatch);
+	if (flags & BLK_MQ_INSERT_AT_HEAD) {
+		list_add(&rq->queuelist, &per_prio->dispatch);
+		rq->fifo_time = jiffies;
 	} else {
-		deadline_add_rq_rb(dd, rq);
+		struct list_head *insert_before;
+
+		deadline_add_rq_rb(per_prio, rq);
 
 		if (rq_mergeable(rq)) {
 			elv_rqhash_add(q, rq);
@@ -516,15 +841,33 @@ static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
 		 * set expire time and add to fifo list
 		 */
 		rq->fifo_time = jiffies + dd->fifo_expire[data_dir];
-		list_add_tail(&rq->queuelist, &dd->fifo_list[data_dir]);
+		insert_before = &per_prio->fifo_list[data_dir];
+#ifdef CONFIG_BLK_DEV_ZONED
+		/*
+		 * Insert zoned writes such that requests are sorted by
+		 * position per zone.
+		 */
+		if (blk_rq_is_seq_zoned_write(rq)) {
+			struct request *rq2 = deadline_latter_request(rq);
+
+			if (rq2 && blk_rq_zone_no(rq2) == blk_rq_zone_no(rq))
+				insert_before = &rq2->queuelist;
+		}
+#endif
+		list_add_tail(&rq->queuelist, insert_before);
 	}
 }
 
+/*
+ * Called from blk_mq_insert_request() or blk_mq_dispatch_plug_list().
+ */
 static void dd_insert_requests(struct blk_mq_hw_ctx *hctx,
-			       struct list_head *list, bool at_head)
+			       struct list_head *list,
+			       blk_insert_t flags)
 {
 	struct request_queue *q = hctx->queue;
 	struct deadline_data *dd = q->elevator->elevator_data;
+	LIST_HEAD(free);
 
 	spin_lock(&dd->lock);
 	while (!list_empty(list)) {
@@ -532,20 +875,34 @@ static void dd_insert_requests(struct blk_mq_hw_ctx *hctx,
 
 		rq = list_first_entry(list, struct request, queuelist);
 		list_del_init(&rq->queuelist);
-		dd_insert_request(hctx, rq, at_head);
+		dd_insert_request(hctx, rq, flags, &free);
 	}
 	spin_unlock(&dd->lock);
+
+	blk_mq_free_requests(&free);
 }
 
-/*
- * Nothing to do here. This is defined only to ensure that .finish_request
- * method is called upon request completion.
- */
-static void dd_prepare_request(struct request *rq, struct bio *bio)
+/* Callback from inside blk_mq_rq_ctx_init(). */
+static void dd_prepare_request(struct request *rq)
+{
+	rq->elv.priv[0] = NULL;
+}
+
+static bool dd_has_write_work(struct blk_mq_hw_ctx *hctx)
 {
+	struct deadline_data *dd = hctx->queue->elevator->elevator_data;
+	enum dd_prio p;
+
+	for (p = 0; p <= DD_PRIO_MAX; p++)
+		if (!list_empty_careful(&dd->per_prio[p].fifo_list[DD_WRITE]))
+			return true;
+
+	return false;
 }
 
 /*
+ * Callback from inside blk_mq_free_request().
+ *
  * For zoned block devices, write unlock the target zone of
  * completed write requests. Do this while holding the zone lock
  * spinlock so that the zone is never unlocked while deadline_fifo_request()
@@ -562,83 +919,103 @@ static void dd_prepare_request(struct request *rq, struct bio *bio)
 static void dd_finish_request(struct request *rq)
 {
 	struct request_queue *q = rq->q;
+	struct deadline_data *dd = q->elevator->elevator_data;
+	const u8 ioprio_class = dd_rq_ioclass(rq);
+	const enum dd_prio prio = ioprio_class_to_prio[ioprio_class];
+	struct dd_per_prio *per_prio = &dd->per_prio[prio];
+
+	/*
+	 * The block layer core may call dd_finish_request() without having
+	 * called dd_insert_requests(). Skip requests that bypassed I/O
+	 * scheduling. See also blk_mq_request_bypass_insert().
+	 */
+	if (!rq->elv.priv[0])
+		return;
+
+	atomic_inc(&per_prio->stats.completed);
 
 	if (blk_queue_is_zoned(q)) {
-		struct deadline_data *dd = q->elevator->elevator_data;
 		unsigned long flags;
 
 		spin_lock_irqsave(&dd->zone_lock, flags);
 		blk_req_zone_write_unlock(rq);
-		if (!list_empty(&dd->fifo_list[WRITE]))
-			blk_mq_sched_mark_restart_hctx(rq->mq_hctx);
 		spin_unlock_irqrestore(&dd->zone_lock, flags);
+
+		if (dd_has_write_work(rq->mq_hctx))
+			blk_mq_sched_mark_restart_hctx(rq->mq_hctx);
 	}
 }
 
+static bool dd_has_work_for_prio(struct dd_per_prio *per_prio)
+{
+	return !list_empty_careful(&per_prio->dispatch) ||
+		!list_empty_careful(&per_prio->fifo_list[DD_READ]) ||
+		!list_empty_careful(&per_prio->fifo_list[DD_WRITE]);
+}
+
 static bool dd_has_work(struct blk_mq_hw_ctx *hctx)
 {
 	struct deadline_data *dd = hctx->queue->elevator->elevator_data;
+	enum dd_prio prio;
 
-	return !list_empty_careful(&dd->dispatch) ||
-		!list_empty_careful(&dd->fifo_list[0]) ||
-		!list_empty_careful(&dd->fifo_list[1]);
+	for (prio = 0; prio <= DD_PRIO_MAX; prio++)
+		if (dd_has_work_for_prio(&dd->per_prio[prio]))
+			return true;
+
+	return false;
 }
 
 /*
  * sysfs parts below
  */
-static ssize_t
-deadline_var_show(int var, char *page)
-{
-	return sprintf(page, "%d\n", var);
-}
-
-static void
-deadline_var_store(int *var, const char *page)
-{
-	char *p = (char *) page;
-
-	*var = simple_strtol(p, &p, 10);
-}
-
-#define SHOW_FUNCTION(__FUNC, __VAR, __CONV)				\
+#define SHOW_INT(__FUNC, __VAR)						\
 static ssize_t __FUNC(struct elevator_queue *e, char *page)		\
 {									\
 	struct deadline_data *dd = e->elevator_data;			\
-	int __data = __VAR;						\
-	if (__CONV)							\
-		__data = jiffies_to_msecs(__data);			\
-	return deadline_var_show(__data, (page));			\
-}
-SHOW_FUNCTION(deadline_read_expire_show, dd->fifo_expire[READ], 1);
-SHOW_FUNCTION(deadline_write_expire_show, dd->fifo_expire[WRITE], 1);
-SHOW_FUNCTION(deadline_writes_starved_show, dd->writes_starved, 0);
-SHOW_FUNCTION(deadline_front_merges_show, dd->front_merges, 0);
-SHOW_FUNCTION(deadline_fifo_batch_show, dd->fifo_batch, 0);
-#undef SHOW_FUNCTION
+									\
+	return sysfs_emit(page, "%d\n", __VAR);				\
+}
+#define SHOW_JIFFIES(__FUNC, __VAR) SHOW_INT(__FUNC, jiffies_to_msecs(__VAR))
+SHOW_JIFFIES(deadline_read_expire_show, dd->fifo_expire[DD_READ]);
+SHOW_JIFFIES(deadline_write_expire_show, dd->fifo_expire[DD_WRITE]);
+SHOW_JIFFIES(deadline_prio_aging_expire_show, dd->prio_aging_expire);
+SHOW_INT(deadline_writes_starved_show, dd->writes_starved);
+SHOW_INT(deadline_front_merges_show, dd->front_merges);
+SHOW_INT(deadline_async_depth_show, dd->async_depth);
+SHOW_INT(deadline_fifo_batch_show, dd->fifo_batch);
+#undef SHOW_INT
+#undef SHOW_JIFFIES
 
 #define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV)			\
 static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count)	\
 {									\
 	struct deadline_data *dd = e->elevator_data;			\
-	int __data;							\
-	deadline_var_store(&__data, (page));				\
+	int __data, __ret;						\
+									\
+	__ret = kstrtoint(page, 0, &__data);				\
+	if (__ret < 0)							\
+		return __ret;						\
 	if (__data < (MIN))						\
 		__data = (MIN);						\
 	else if (__data > (MAX))					\
 		__data = (MAX);						\
-	if (__CONV)							\
-		*(__PTR) = msecs_to_jiffies(__data);			\
-	else								\
-		*(__PTR) = __data;					\
+	*(__PTR) = __CONV(__data);					\
 	return count;							\
 }
-STORE_FUNCTION(deadline_read_expire_store, &dd->fifo_expire[READ], 0, INT_MAX, 1);
-STORE_FUNCTION(deadline_write_expire_store, &dd->fifo_expire[WRITE], 0, INT_MAX, 1);
-STORE_FUNCTION(deadline_writes_starved_store, &dd->writes_starved, INT_MIN, INT_MAX, 0);
-STORE_FUNCTION(deadline_front_merges_store, &dd->front_merges, 0, 1, 0);
-STORE_FUNCTION(deadline_fifo_batch_store, &dd->fifo_batch, 0, INT_MAX, 0);
+#define STORE_INT(__FUNC, __PTR, MIN, MAX)				\
+	STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, )
+#define STORE_JIFFIES(__FUNC, __PTR, MIN, MAX)				\
+	STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, msecs_to_jiffies)
+STORE_JIFFIES(deadline_read_expire_store, &dd->fifo_expire[DD_READ], 0, INT_MAX);
+STORE_JIFFIES(deadline_write_expire_store, &dd->fifo_expire[DD_WRITE], 0, INT_MAX);
+STORE_JIFFIES(deadline_prio_aging_expire_store, &dd->prio_aging_expire, 0, INT_MAX);
+STORE_INT(deadline_writes_starved_store, &dd->writes_starved, INT_MIN, INT_MAX);
+STORE_INT(deadline_front_merges_store, &dd->front_merges, 0, 1);
+STORE_INT(deadline_async_depth_store, &dd->async_depth, 1, INT_MAX);
+STORE_INT(deadline_fifo_batch_store, &dd->fifo_batch, 0, INT_MAX);
 #undef STORE_FUNCTION
+#undef STORE_INT
+#undef STORE_JIFFIES
 
 #define DD_ATTR(name) \
 	__ATTR(name, 0644, deadline_##name##_show, deadline_##name##_store)
@@ -648,21 +1025,24 @@ static struct elv_fs_entry deadline_attrs[] = {
 	DD_ATTR(write_expire),
 	DD_ATTR(writes_starved),
 	DD_ATTR(front_merges),
+	DD_ATTR(async_depth),
 	DD_ATTR(fifo_batch),
+	DD_ATTR(prio_aging_expire),
 	__ATTR_NULL
 };
 
 #ifdef CONFIG_BLK_DEBUG_FS
-#define DEADLINE_DEBUGFS_DDIR_ATTRS(ddir, name)				\
+#define DEADLINE_DEBUGFS_DDIR_ATTRS(prio, data_dir, 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;		\
+	struct dd_per_prio *per_prio = &dd->per_prio[prio];		\
 									\
 	spin_lock(&dd->lock);						\
-	return seq_list_start(&dd->fifo_list[ddir], *pos);		\
+	return seq_list_start(&per_prio->fifo_list[data_dir], *pos);	\
 }									\
 									\
 static void *deadline_##name##_fifo_next(struct seq_file *m, void *v,	\
@@ -670,8 +1050,9 @@ static void *deadline_##name##_fifo_next(struct seq_file *m, void *v,	\
 {									\
 	struct request_queue *q = m->private;				\
 	struct deadline_data *dd = q->elevator->elevator_data;		\
+	struct dd_per_prio *per_prio = &dd->per_prio[prio];		\
 									\
-	return seq_list_next(v, &dd->fifo_list[ddir], pos);		\
+	return seq_list_next(v, &per_prio->fifo_list[data_dir], pos);	\
 }									\
 									\
 static void deadline_##name##_fifo_stop(struct seq_file *m, void *v)	\
@@ -695,14 +1076,22 @@ static int deadline_##name##_next_rq_show(void *data,			\
 {									\
 	struct request_queue *q = data;					\
 	struct deadline_data *dd = q->elevator->elevator_data;		\
-	struct request *rq = dd->next_rq[ddir];				\
+	struct dd_per_prio *per_prio = &dd->per_prio[prio];		\
+	struct request *rq;						\
 									\
+	rq = deadline_from_pos(per_prio, data_dir,			\
+			       per_prio->latest_pos[data_dir]);		\
 	if (rq)								\
 		__blk_mq_debugfs_rq_show(m, rq);			\
 	return 0;							\
 }
-DEADLINE_DEBUGFS_DDIR_ATTRS(READ, read)
-DEADLINE_DEBUGFS_DDIR_ATTRS(WRITE, write)
+
+DEADLINE_DEBUGFS_DDIR_ATTRS(DD_RT_PRIO, DD_READ, read0);
+DEADLINE_DEBUGFS_DDIR_ATTRS(DD_RT_PRIO, DD_WRITE, write0);
+DEADLINE_DEBUGFS_DDIR_ATTRS(DD_BE_PRIO, DD_READ, read1);
+DEADLINE_DEBUGFS_DDIR_ATTRS(DD_BE_PRIO, DD_WRITE, write1);
+DEADLINE_DEBUGFS_DDIR_ATTRS(DD_IDLE_PRIO, DD_READ, read2);
+DEADLINE_DEBUGFS_DDIR_ATTRS(DD_IDLE_PRIO, DD_WRITE, write2);
 #undef DEADLINE_DEBUGFS_DDIR_ATTRS
 
 static int deadline_batching_show(void *data, struct seq_file *m)
@@ -723,49 +1112,130 @@ static int deadline_starved_show(void *data, struct seq_file *m)
 	return 0;
 }
 
-static void *deadline_dispatch_start(struct seq_file *m, loff_t *pos)
-	__acquires(&dd->lock)
+static int dd_async_depth_show(void *data, struct seq_file *m)
 {
-	struct request_queue *q = m->private;
+	struct request_queue *q = data;
 	struct deadline_data *dd = q->elevator->elevator_data;
 
-	spin_lock(&dd->lock);
-	return seq_list_start(&dd->dispatch, *pos);
+	seq_printf(m, "%u\n", dd->async_depth);
+	return 0;
 }
 
-static void *deadline_dispatch_next(struct seq_file *m, void *v, loff_t *pos)
+static int dd_queued_show(void *data, struct seq_file *m)
 {
-	struct request_queue *q = m->private;
+	struct request_queue *q = data;
 	struct deadline_data *dd = q->elevator->elevator_data;
+	u32 rt, be, idle;
+
+	spin_lock(&dd->lock);
+	rt = dd_queued(dd, DD_RT_PRIO);
+	be = dd_queued(dd, DD_BE_PRIO);
+	idle = dd_queued(dd, DD_IDLE_PRIO);
+	spin_unlock(&dd->lock);
+
+	seq_printf(m, "%u %u %u\n", rt, be, idle);
+
+	return 0;
+}
+
+/* Number of requests owned by the block driver for a given priority. */
+static u32 dd_owned_by_driver(struct deadline_data *dd, enum dd_prio prio)
+{
+	const struct io_stats_per_prio *stats = &dd->per_prio[prio].stats;
 
-	return seq_list_next(v, &dd->dispatch, pos);
+	lockdep_assert_held(&dd->lock);
+
+	return stats->dispatched + stats->merged -
+		atomic_read(&stats->completed);
 }
 
-static void deadline_dispatch_stop(struct seq_file *m, void *v)
-	__releases(&dd->lock)
+static int dd_owned_by_driver_show(void *data, struct seq_file *m)
 {
-	struct request_queue *q = m->private;
+	struct request_queue *q = data;
 	struct deadline_data *dd = q->elevator->elevator_data;
+	u32 rt, be, idle;
 
+	spin_lock(&dd->lock);
+	rt = dd_owned_by_driver(dd, DD_RT_PRIO);
+	be = dd_owned_by_driver(dd, DD_BE_PRIO);
+	idle = dd_owned_by_driver(dd, DD_IDLE_PRIO);
 	spin_unlock(&dd->lock);
+
+	seq_printf(m, "%u %u %u\n", rt, be, idle);
+
+	return 0;
 }
 
-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_DISPATCH_ATTR(prio)					\
+static void *deadline_dispatch##prio##_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;		\
+	struct dd_per_prio *per_prio = &dd->per_prio[prio];		\
+									\
+	spin_lock(&dd->lock);						\
+	return seq_list_start(&per_prio->dispatch, *pos);		\
+}									\
+									\
+static void *deadline_dispatch##prio##_next(struct seq_file *m,		\
+					    void *v, loff_t *pos)	\
+{									\
+	struct request_queue *q = m->private;				\
+	struct deadline_data *dd = q->elevator->elevator_data;		\
+	struct dd_per_prio *per_prio = &dd->per_prio[prio];		\
+									\
+	return seq_list_next(v, &per_prio->dispatch, pos);		\
+}									\
+									\
+static void deadline_dispatch##prio##_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##prio##_seq_ops = { \
+	.start	= deadline_dispatch##prio##_start,			\
+	.next	= deadline_dispatch##prio##_next,			\
+	.stop	= deadline_dispatch##prio##_stop,			\
+	.show	= blk_mq_debugfs_rq_show,				\
+}
+
+DEADLINE_DISPATCH_ATTR(0);
+DEADLINE_DISPATCH_ATTR(1);
+DEADLINE_DISPATCH_ATTR(2);
+#undef DEADLINE_DISPATCH_ATTR
 
-#define DEADLINE_QUEUE_DDIR_ATTRS(name)						\
-	{#name "_fifo_list", 0400, .seq_ops = &deadline_##name##_fifo_seq_ops},	\
+#define DEADLINE_QUEUE_DDIR_ATTRS(name)					\
+	{#name "_fifo_list", 0400,					\
+			.seq_ops = &deadline_##name##_fifo_seq_ops}
+#define DEADLINE_NEXT_RQ_ATTR(name)					\
 	{#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),
+	DEADLINE_QUEUE_DDIR_ATTRS(read0),
+	DEADLINE_QUEUE_DDIR_ATTRS(write0),
+	DEADLINE_QUEUE_DDIR_ATTRS(read1),
+	DEADLINE_QUEUE_DDIR_ATTRS(write1),
+	DEADLINE_QUEUE_DDIR_ATTRS(read2),
+	DEADLINE_QUEUE_DDIR_ATTRS(write2),
+	DEADLINE_NEXT_RQ_ATTR(read0),
+	DEADLINE_NEXT_RQ_ATTR(write0),
+	DEADLINE_NEXT_RQ_ATTR(read1),
+	DEADLINE_NEXT_RQ_ATTR(write1),
+	DEADLINE_NEXT_RQ_ATTR(read2),
+	DEADLINE_NEXT_RQ_ATTR(write2),
 	{"batching", 0400, deadline_batching_show},
 	{"starved", 0400, deadline_starved_show},
-	{"dispatch", 0400, .seq_ops = &deadline_dispatch_seq_ops},
+	{"async_depth", 0400, dd_async_depth_show},
+	{"dispatch0", 0400, .seq_ops = &deadline_dispatch0_seq_ops},
+	{"dispatch1", 0400, .seq_ops = &deadline_dispatch1_seq_ops},
+	{"dispatch2", 0400, .seq_ops = &deadline_dispatch2_seq_ops},
+	{"owned_by_driver", 0400, dd_owned_by_driver_show},
+	{"queued", 0400, dd_queued_show},
 	{},
 };
 #undef DEADLINE_QUEUE_DDIR_ATTRS
@@ -773,6 +1243,8 @@ static const struct blk_mq_debugfs_attr deadline_queue_debugfs_attrs[] = {
 
 static struct elevator_type mq_deadline = {
 	.ops = {
+		.depth_updated		= dd_depth_updated,
+		.limit_depth		= dd_limit_depth,
 		.insert_requests	= dd_insert_requests,
 		.dispatch_request	= dd_dispatch_request,
 		.prepare_request	= dd_prepare_request,
@@ -784,8 +1256,9 @@ static struct elevator_type mq_deadline = {
 		.requests_merged	= dd_merged_requests,
 		.request_merged		= dd_request_merged,
 		.has_work		= dd_has_work,
-		.init_sched		= dd_init_queue,
-		.exit_sched		= dd_exit_queue,
+		.init_sched		= dd_init_sched,
+		.exit_sched		= dd_exit_sched,
+		.init_hctx		= dd_init_hctx,
 	},
 
 #ifdef CONFIG_BLK_DEBUG_FS
@@ -812,6 +1285,6 @@ static void __exit deadline_exit(void)
 module_init(deadline_init);
 module_exit(deadline_exit);
 
-MODULE_AUTHOR("Jens Axboe");
+MODULE_AUTHOR("Jens Axboe, Damien Le Moal and Bart Van Assche");
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("MQ deadline IO scheduler");