diff --git a/Documentation/block/biodoc.txt b/Documentation/block/biodoc.txt
index bcdb2b4..918e1e0 100644
--- a/Documentation/block/biodoc.txt
+++ b/Documentation/block/biodoc.txt
@@ -115,7 +115,7 @@
 
 Various parameters that the generic i/o scheduler logic uses are set at
 a per-queue level (e.g maximum request size, maximum number of segments in
-a scatter-gather list, hardsect size)
+a scatter-gather list, logical block size)
 
 Some parameters that were earlier available as global arrays indexed by
 major/minor are now directly associated with the queue. Some of these may
@@ -156,7 +156,7 @@
 	blk_queue_max_segment_size(q, max_seg_size)
 		Maximum size of a clustered segment, 64kB default.
 
-	blk_queue_hardsect_size(q, hardsect_size)
+	blk_queue_logical_block_size(q, logical_block_size)
 		Lowest possible sector size that the hardware can operate
 		on, 512 bytes default.
 
diff --git a/MAINTAINERS b/MAINTAINERS
index 2556558..fb4d381 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2472,6 +2472,7 @@
 S:	Maintained
 F:	block/
 F:	kernel/trace/blktrace.c
+F:	lib/sbitmap.c
 
 BLOCK2MTD DRIVER
 M:	Joern Engel <joern@lazybastard.org>
diff --git a/block/Kconfig b/block/Kconfig
index 161491d..5136ad4 100644
--- a/block/Kconfig
+++ b/block/Kconfig
@@ -4,6 +4,7 @@
 menuconfig BLOCK
        bool "Enable the block layer" if EXPERT
        default y
+       select SBITMAP
        help
 	 Provide block layer support for the kernel.
 
diff --git a/block/bio.c b/block/bio.c
index aa73540..db85c57 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1068,7 +1068,7 @@
 	return 0;
 }
 
-static void bio_free_pages(struct bio *bio)
+void bio_free_pages(struct bio *bio)
 {
 	struct bio_vec *bvec;
 	int i;
@@ -1076,6 +1076,7 @@
 	bio_for_each_segment_all(bvec, bio, i)
 		__free_page(bvec->bv_page);
 }
+EXPORT_SYMBOL(bio_free_pages);
 
 /**
  *	bio_uncopy_user	-	finish previously mapped bio
@@ -1274,7 +1275,7 @@
 
 		nr_pages += end - start;
 		/*
-		 * buffer must be aligned to at least hardsector size for now
+		 * buffer must be aligned to at least logical block size for now
 		 */
 		if (uaddr & queue_dma_alignment(q))
 			return ERR_PTR(-EINVAL);
diff --git a/block/blk-core.c b/block/blk-core.c
index 36c7ac3..14d7c07 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -288,7 +288,7 @@
 		int i;
 
 		queue_for_each_hw_ctx(q, hctx, i) {
-			cancel_delayed_work_sync(&hctx->run_work);
+			cancel_work_sync(&hctx->run_work);
 			cancel_delayed_work_sync(&hctx->delay_work);
 		}
 	} else {
@@ -3097,6 +3097,12 @@
 }
 EXPORT_SYMBOL(kblockd_schedule_work);
 
+int kblockd_schedule_work_on(int cpu, struct work_struct *work)
+{
+	return queue_work_on(cpu, kblockd_workqueue, work);
+}
+EXPORT_SYMBOL(kblockd_schedule_work_on);
+
 int kblockd_schedule_delayed_work(struct delayed_work *dwork,
 				  unsigned long delay)
 {
@@ -3301,19 +3307,23 @@
 {
 	struct blk_plug *plug;
 	long state;
+	unsigned int queue_num;
+	struct blk_mq_hw_ctx *hctx;
 
 	if (!q->mq_ops || !q->mq_ops->poll || !blk_qc_t_valid(cookie) ||
 	    !test_bit(QUEUE_FLAG_POLL, &q->queue_flags))
 		return false;
 
+	queue_num = blk_qc_t_to_queue_num(cookie);
+	hctx = q->queue_hw_ctx[queue_num];
+	hctx->poll_considered++;
+
 	plug = current->plug;
 	if (plug)
 		blk_flush_plug_list(plug, false);
 
 	state = current->state;
 	while (!need_resched()) {
-		unsigned int queue_num = blk_qc_t_to_queue_num(cookie);
-		struct blk_mq_hw_ctx *hctx = q->queue_hw_ctx[queue_num];
 		int ret;
 
 		hctx->poll_invoked++;
diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c
index fe822aa..01fb455 100644
--- a/block/blk-mq-sysfs.c
+++ b/block/blk-mq-sysfs.c
@@ -176,7 +176,17 @@
 
 static ssize_t blk_mq_hw_sysfs_poll_show(struct blk_mq_hw_ctx *hctx, char *page)
 {
-	return sprintf(page, "invoked=%lu, success=%lu\n", hctx->poll_invoked, hctx->poll_success);
+	return sprintf(page, "considered=%lu, invoked=%lu, success=%lu\n",
+		       hctx->poll_considered, hctx->poll_invoked,
+		       hctx->poll_success);
+}
+
+static ssize_t blk_mq_hw_sysfs_poll_store(struct blk_mq_hw_ctx *hctx,
+					  const char *page, size_t size)
+{
+	hctx->poll_considered = hctx->poll_invoked = hctx->poll_success = 0;
+
+	return size;
 }
 
 static ssize_t blk_mq_hw_sysfs_queued_show(struct blk_mq_hw_ctx *hctx,
@@ -198,12 +208,14 @@
 
 	page += sprintf(page, "%8u\t%lu\n", 0U, hctx->dispatched[0]);
 
-	for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER; i++) {
-		unsigned long d = 1U << (i - 1);
+	for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER - 1; i++) {
+		unsigned int d = 1U << (i - 1);
 
-		page += sprintf(page, "%8lu\t%lu\n", d, hctx->dispatched[i]);
+		page += sprintf(page, "%8u\t%lu\n", d, hctx->dispatched[i]);
 	}
 
+	page += sprintf(page, "%8u+\t%lu\n", 1U << (i - 1),
+						hctx->dispatched[i]);
 	return page - start_page;
 }
 
@@ -301,8 +313,9 @@
 	.show = blk_mq_hw_sysfs_cpus_show,
 };
 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_poll = {
-	.attr = {.name = "io_poll", .mode = S_IRUGO },
+	.attr = {.name = "io_poll", .mode = S_IWUSR | S_IRUGO },
 	.show = blk_mq_hw_sysfs_poll_show,
+	.store = blk_mq_hw_sysfs_poll_store,
 };
 
 static struct attribute *default_hw_ctx_attrs[] = {
@@ -380,9 +393,8 @@
 	return ret;
 }
 
-static void __blk_mq_unregister_disk(struct gendisk *disk)
+static void __blk_mq_unregister_dev(struct device *dev, struct request_queue *q)
 {
-	struct request_queue *q = disk->queue;
 	struct blk_mq_hw_ctx *hctx;
 	struct blk_mq_ctx *ctx;
 	int i, j;
@@ -400,15 +412,15 @@
 	kobject_del(&q->mq_kobj);
 	kobject_put(&q->mq_kobj);
 
-	kobject_put(&disk_to_dev(disk)->kobj);
+	kobject_put(&dev->kobj);
 
 	q->mq_sysfs_init_done = false;
 }
 
-void blk_mq_unregister_disk(struct gendisk *disk)
+void blk_mq_unregister_dev(struct device *dev, struct request_queue *q)
 {
 	blk_mq_disable_hotplug();
-	__blk_mq_unregister_disk(disk);
+	__blk_mq_unregister_dev(dev, q);
 	blk_mq_enable_hotplug();
 }
 
@@ -430,10 +442,8 @@
 	}
 }
 
-int blk_mq_register_disk(struct gendisk *disk)
+int blk_mq_register_dev(struct device *dev, struct request_queue *q)
 {
-	struct device *dev = disk_to_dev(disk);
-	struct request_queue *q = disk->queue;
 	struct blk_mq_hw_ctx *hctx;
 	int ret, i;
 
@@ -454,7 +464,7 @@
 	}
 
 	if (ret)
-		__blk_mq_unregister_disk(disk);
+		__blk_mq_unregister_dev(dev, q);
 	else
 		q->mq_sysfs_init_done = true;
 out:
@@ -462,7 +472,7 @@
 
 	return ret;
 }
-EXPORT_SYMBOL_GPL(blk_mq_register_disk);
+EXPORT_SYMBOL_GPL(blk_mq_register_dev);
 
 void blk_mq_sysfs_unregister(struct request_queue *q)
 {
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index 729bac3..cef618f 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -1,58 +1,24 @@
 /*
- * Fast and scalable bitmap tagging variant. Uses sparser bitmaps spread
- * over multiple cachelines to avoid ping-pong between multiple submitters
- * or submitter and completer. Uses rolling wakeups to avoid falling of
- * the scaling cliff when we run out of tags and have to start putting
- * submitters to sleep.
- *
- * Uses active queue tracking to support fairer distribution of tags
- * between multiple submitters when a shared tag map is used.
+ * Tag allocation using scalable bitmaps. Uses active queue tracking to support
+ * fairer distribution of tags between multiple submitters when a shared tag map
+ * is used.
  *
  * Copyright (C) 2013-2014 Jens Axboe
  */
 #include <linux/kernel.h>
 #include <linux/module.h>
-#include <linux/random.h>
 
 #include <linux/blk-mq.h>
 #include "blk.h"
 #include "blk-mq.h"
 #include "blk-mq-tag.h"
 
-static bool bt_has_free_tags(struct blk_mq_bitmap_tags *bt)
-{
-	int i;
-
-	for (i = 0; i < bt->map_nr; i++) {
-		struct blk_align_bitmap *bm = &bt->map[i];
-		int ret;
-
-		ret = find_first_zero_bit(&bm->word, bm->depth);
-		if (ret < bm->depth)
-			return true;
-	}
-
-	return false;
-}
-
 bool blk_mq_has_free_tags(struct blk_mq_tags *tags)
 {
 	if (!tags)
 		return true;
 
-	return bt_has_free_tags(&tags->bitmap_tags);
-}
-
-static inline int bt_index_inc(int index)
-{
-	return (index + 1) & (BT_WAIT_QUEUES - 1);
-}
-
-static inline void bt_index_atomic_inc(atomic_t *index)
-{
-	int old = atomic_read(index);
-	int new = bt_index_inc(old);
-	atomic_cmpxchg(index, old, new);
+	return sbitmap_any_bit_clear(&tags->bitmap_tags.sb);
 }
 
 /*
@@ -72,29 +38,9 @@
  */
 void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags, bool include_reserve)
 {
-	struct blk_mq_bitmap_tags *bt;
-	int i, wake_index;
-
-	/*
-	 * Make sure all changes prior to this are visible from other CPUs.
-	 */
-	smp_mb();
-	bt = &tags->bitmap_tags;
-	wake_index = atomic_read(&bt->wake_index);
-	for (i = 0; i < BT_WAIT_QUEUES; i++) {
-		struct bt_wait_state *bs = &bt->bs[wake_index];
-
-		if (waitqueue_active(&bs->wait))
-			wake_up(&bs->wait);
-
-		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);
-	}
+	sbitmap_queue_wake_all(&tags->bitmap_tags);
+	if (include_reserve)
+		sbitmap_queue_wake_all(&tags->breserved_tags);
 }
 
 /*
@@ -118,7 +64,7 @@
  * and attempt to provide a fair share of the tag depth for each of them.
  */
 static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx,
-				  struct blk_mq_bitmap_tags *bt)
+				  struct sbitmap_queue *bt)
 {
 	unsigned int depth, users;
 
@@ -130,7 +76,7 @@
 	/*
 	 * Don't try dividing an ant
 	 */
-	if (bt->depth == 1)
+	if (bt->sb.depth == 1)
 		return true;
 
 	users = atomic_read(&hctx->tags->active_queues);
@@ -140,142 +86,36 @@
 	/*
 	 * Allow at least some tags
 	 */
-	depth = max((bt->depth + users - 1) / users, 4U);
+	depth = max((bt->sb.depth + users - 1) / users, 4U);
 	return atomic_read(&hctx->nr_active) < depth;
 }
 
-static int __bt_get_word(struct blk_align_bitmap *bm, unsigned int last_tag,
-			 bool nowrap)
+static int __bt_get(struct blk_mq_hw_ctx *hctx, struct sbitmap_queue *bt)
 {
-	int tag, org_last_tag = last_tag;
-
-	while (1) {
-		tag = find_next_zero_bit(&bm->word, bm->depth, last_tag);
-		if (unlikely(tag >= bm->depth)) {
-			/*
-			 * We started with an offset, and we didn't reset the
-			 * offset to 0 in a failure case, so start from 0 to
-			 * exhaust the map.
-			 */
-			if (org_last_tag && last_tag && !nowrap) {
-				last_tag = org_last_tag = 0;
-				continue;
-			}
-			return -1;
-		}
-
-		if (!test_and_set_bit(tag, &bm->word))
-			break;
-
-		last_tag = tag + 1;
-		if (last_tag >= bm->depth - 1)
-			last_tag = 0;
-	}
-
-	return tag;
-}
-
-#define BT_ALLOC_RR(tags) (tags->alloc_policy == BLK_TAG_ALLOC_RR)
-
-/*
- * Straight forward bitmap tag implementation, where each bit is a tag
- * (cleared == free, and set == busy). The small twist is using per-cpu
- * last_tag caches, which blk-mq stores in the blk_mq_ctx software queue
- * contexts. This enables us to drastically limit the space searched,
- * without dirtying an extra shared cacheline like we would if we stored
- * the cache value inside the shared blk_mq_bitmap_tags structure. On top
- * of that, each word of tags is in a separate cacheline. This means that
- * multiple users will tend to stick to different cachelines, at least
- * until the map is exhausted.
- */
-static int __bt_get(struct blk_mq_hw_ctx *hctx, struct blk_mq_bitmap_tags *bt,
-		    unsigned int *tag_cache, struct blk_mq_tags *tags)
-{
-	unsigned int last_tag, org_last_tag;
-	int index, i, tag;
-
 	if (!hctx_may_queue(hctx, bt))
 		return -1;
-
-	last_tag = org_last_tag = *tag_cache;
-	index = TAG_TO_INDEX(bt, last_tag);
-
-	for (i = 0; i < bt->map_nr; i++) {
-		tag = __bt_get_word(&bt->map[index], TAG_TO_BIT(bt, last_tag),
-				    BT_ALLOC_RR(tags));
-		if (tag != -1) {
-			tag += (index << bt->bits_per_word);
-			goto done;
-		}
-
-		/*
-		 * Jump to next index, and reset the last tag to be the
-		 * first tag of that index
-		 */
-		index++;
-		last_tag = (index << bt->bits_per_word);
-
-		if (index >= bt->map_nr) {
-			index = 0;
-			last_tag = 0;
-		}
-	}
-
-	*tag_cache = 0;
-	return -1;
-
-	/*
-	 * Only update the cache from the allocation path, if we ended
-	 * up using the specific cached tag.
-	 */
-done:
-	if (tag == org_last_tag || unlikely(BT_ALLOC_RR(tags))) {
-		last_tag = tag + 1;
-		if (last_tag >= bt->depth - 1)
-			last_tag = 0;
-
-		*tag_cache = last_tag;
-	}
-
-	return tag;
+	return __sbitmap_queue_get(bt);
 }
 
-static struct bt_wait_state *bt_wait_ptr(struct blk_mq_bitmap_tags *bt,
-					 struct blk_mq_hw_ctx *hctx)
+static int bt_get(struct blk_mq_alloc_data *data, struct sbitmap_queue *bt,
+		  struct blk_mq_hw_ctx *hctx, struct blk_mq_tags *tags)
 {
-	struct bt_wait_state *bs;
-	int wait_index;
-
-	if (!hctx)
-		return &bt->bs[0];
-
-	wait_index = atomic_read(&hctx->wait_index);
-	bs = &bt->bs[wait_index];
-	bt_index_atomic_inc(&hctx->wait_index);
-	return bs;
-}
-
-static int bt_get(struct blk_mq_alloc_data *data,
-		struct blk_mq_bitmap_tags *bt,
-		struct blk_mq_hw_ctx *hctx,
-		unsigned int *last_tag, struct blk_mq_tags *tags)
-{
-	struct bt_wait_state *bs;
+	struct sbq_wait_state *ws;
 	DEFINE_WAIT(wait);
 	int tag;
 
-	tag = __bt_get(hctx, bt, last_tag, tags);
+	tag = __bt_get(hctx, bt);
 	if (tag != -1)
 		return tag;
 
 	if (data->flags & BLK_MQ_REQ_NOWAIT)
 		return -1;
 
-	bs = bt_wait_ptr(bt, hctx);
+	ws = bt_wait_ptr(bt, hctx);
 	do {
-		prepare_to_wait(&bs->wait, &wait, TASK_UNINTERRUPTIBLE);
+		prepare_to_wait(&ws->wait, &wait, TASK_UNINTERRUPTIBLE);
 
-		tag = __bt_get(hctx, bt, last_tag, tags);
+		tag = __bt_get(hctx, bt);
 		if (tag != -1)
 			break;
 
@@ -292,7 +132,7 @@
 		 * Retry tag allocation after running the hardware queue,
 		 * as running the queue may also have found completions.
 		 */
-		tag = __bt_get(hctx, bt, last_tag, tags);
+		tag = __bt_get(hctx, bt);
 		if (tag != -1)
 			break;
 
@@ -306,15 +146,14 @@
 		if (data->flags & BLK_MQ_REQ_RESERVED) {
 			bt = &data->hctx->tags->breserved_tags;
 		} else {
-			last_tag = &data->ctx->last_tag;
 			hctx = data->hctx;
 			bt = &hctx->tags->bitmap_tags;
 		}
-		finish_wait(&bs->wait, &wait);
-		bs = bt_wait_ptr(bt, hctx);
+		finish_wait(&ws->wait, &wait);
+		ws = bt_wait_ptr(bt, hctx);
 	} while (1);
 
-	finish_wait(&bs->wait, &wait);
+	finish_wait(&ws->wait, &wait);
 	return tag;
 }
 
@@ -323,7 +162,7 @@
 	int tag;
 
 	tag = bt_get(data, &data->hctx->tags->bitmap_tags, data->hctx,
-			&data->ctx->last_tag, data->hctx->tags);
+		     data->hctx->tags);
 	if (tag >= 0)
 		return tag + data->hctx->tags->nr_reserved_tags;
 
@@ -332,15 +171,15 @@
 
 static unsigned int __blk_mq_get_reserved_tag(struct blk_mq_alloc_data *data)
 {
-	int tag, zero = 0;
+	int tag;
 
 	if (unlikely(!data->hctx->tags->nr_reserved_tags)) {
 		WARN_ON_ONCE(1);
 		return BLK_MQ_TAG_FAIL;
 	}
 
-	tag = bt_get(data, &data->hctx->tags->breserved_tags, NULL, &zero,
-		data->hctx->tags);
+	tag = bt_get(data, &data->hctx->tags->breserved_tags, NULL,
+		     data->hctx->tags);
 	if (tag < 0)
 		return BLK_MQ_TAG_FAIL;
 
@@ -354,55 +193,8 @@
 	return __blk_mq_get_tag(data);
 }
 
-static struct bt_wait_state *bt_wake_ptr(struct blk_mq_bitmap_tags *bt)
-{
-	int i, wake_index;
-
-	wake_index = atomic_read(&bt->wake_index);
-	for (i = 0; i < BT_WAIT_QUEUES; i++) {
-		struct bt_wait_state *bs = &bt->bs[wake_index];
-
-		if (waitqueue_active(&bs->wait)) {
-			int o = atomic_read(&bt->wake_index);
-			if (wake_index != o)
-				atomic_cmpxchg(&bt->wake_index, o, wake_index);
-
-			return bs;
-		}
-
-		wake_index = bt_index_inc(wake_index);
-	}
-
-	return NULL;
-}
-
-static void bt_clear_tag(struct blk_mq_bitmap_tags *bt, unsigned int tag)
-{
-	const int index = TAG_TO_INDEX(bt, tag);
-	struct bt_wait_state *bs;
-	int wait_cnt;
-
-	clear_bit(TAG_TO_BIT(bt, tag), &bt->map[index].word);
-
-	/* Ensure that the wait list checks occur after clear_bit(). */
-	smp_mb();
-
-	bs = bt_wake_ptr(bt);
-	if (!bs)
-		return;
-
-	wait_cnt = atomic_dec_return(&bs->wait_cnt);
-	if (unlikely(wait_cnt < 0))
-		wait_cnt = atomic_inc_return(&bs->wait_cnt);
-	if (wait_cnt == 0) {
-		atomic_add(bt->wake_cnt, &bs->wait_cnt);
-		bt_index_atomic_inc(&bt->wake_index);
-		wake_up(&bs->wait);
-	}
-}
-
-void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, unsigned int tag,
-		    unsigned int *last_tag)
+void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
+		    unsigned int tag)
 {
 	struct blk_mq_tags *tags = hctx->tags;
 
@@ -410,67 +202,92 @@
 		const int real_tag = tag - tags->nr_reserved_tags;
 
 		BUG_ON(real_tag >= tags->nr_tags);
-		bt_clear_tag(&tags->bitmap_tags, real_tag);
-		if (likely(tags->alloc_policy == BLK_TAG_ALLOC_FIFO))
-			*last_tag = real_tag;
+		sbitmap_queue_clear(&tags->bitmap_tags, real_tag, ctx->cpu);
 	} else {
 		BUG_ON(tag >= tags->nr_reserved_tags);
-		bt_clear_tag(&tags->breserved_tags, tag);
+		sbitmap_queue_clear(&tags->breserved_tags, tag, ctx->cpu);
 	}
 }
 
-static void bt_for_each(struct blk_mq_hw_ctx *hctx,
-		struct blk_mq_bitmap_tags *bt, unsigned int off,
-		busy_iter_fn *fn, void *data, bool reserved)
+struct bt_iter_data {
+	struct blk_mq_hw_ctx *hctx;
+	busy_iter_fn *fn;
+	void *data;
+	bool reserved;
+};
+
+static bool bt_iter(struct sbitmap *bitmap, unsigned int bitnr, void *data)
 {
+	struct bt_iter_data *iter_data = data;
+	struct blk_mq_hw_ctx *hctx = iter_data->hctx;
+	struct blk_mq_tags *tags = hctx->tags;
+	bool reserved = iter_data->reserved;
 	struct request *rq;
-	int bit, i;
 
-	for (i = 0; i < bt->map_nr; i++) {
-		struct blk_align_bitmap *bm = &bt->map[i];
+	if (!reserved)
+		bitnr += tags->nr_reserved_tags;
+	rq = tags->rqs[bitnr];
 
-		for (bit = find_first_bit(&bm->word, bm->depth);
-		     bit < bm->depth;
-		     bit = find_next_bit(&bm->word, bm->depth, bit + 1)) {
-			rq = hctx->tags->rqs[off + bit];
-			if (rq->q == hctx->queue)
-				fn(hctx, rq, data, reserved);
-		}
-
-		off += (1 << bt->bits_per_word);
-	}
+	if (rq->q == hctx->queue)
+		iter_data->fn(hctx, rq, iter_data->data, reserved);
+	return true;
 }
 
-static void bt_tags_for_each(struct blk_mq_tags *tags,
-		struct blk_mq_bitmap_tags *bt, unsigned int off,
-		busy_tag_iter_fn *fn, void *data, bool reserved)
+static void bt_for_each(struct blk_mq_hw_ctx *hctx, struct sbitmap_queue *bt,
+			busy_iter_fn *fn, void *data, bool reserved)
 {
+	struct bt_iter_data iter_data = {
+		.hctx = hctx,
+		.fn = fn,
+		.data = data,
+		.reserved = reserved,
+	};
+
+	sbitmap_for_each_set(&bt->sb, bt_iter, &iter_data);
+}
+
+struct bt_tags_iter_data {
+	struct blk_mq_tags *tags;
+	busy_tag_iter_fn *fn;
+	void *data;
+	bool reserved;
+};
+
+static bool bt_tags_iter(struct sbitmap *bitmap, unsigned int bitnr, void *data)
+{
+	struct bt_tags_iter_data *iter_data = data;
+	struct blk_mq_tags *tags = iter_data->tags;
+	bool reserved = iter_data->reserved;
 	struct request *rq;
-	int bit, i;
 
-	if (!tags->rqs)
-		return;
-	for (i = 0; i < bt->map_nr; i++) {
-		struct blk_align_bitmap *bm = &bt->map[i];
+	if (!reserved)
+		bitnr += tags->nr_reserved_tags;
+	rq = tags->rqs[bitnr];
 
-		for (bit = find_first_bit(&bm->word, bm->depth);
-		     bit < bm->depth;
-		     bit = find_next_bit(&bm->word, bm->depth, bit + 1)) {
-			rq = tags->rqs[off + bit];
-			fn(rq, data, reserved);
-		}
+	iter_data->fn(rq, iter_data->data, reserved);
+	return true;
+}
 
-		off += (1 << bt->bits_per_word);
-	}
+static void bt_tags_for_each(struct blk_mq_tags *tags, struct sbitmap_queue *bt,
+			     busy_tag_iter_fn *fn, void *data, bool reserved)
+{
+	struct bt_tags_iter_data iter_data = {
+		.tags = tags,
+		.fn = fn,
+		.data = data,
+		.reserved = reserved,
+	};
+
+	if (tags->rqs)
+		sbitmap_for_each_set(&bt->sb, bt_tags_iter, &iter_data);
 }
 
 static void blk_mq_all_tag_busy_iter(struct blk_mq_tags *tags,
 		busy_tag_iter_fn *fn, void *priv)
 {
 	if (tags->nr_reserved_tags)
-		bt_tags_for_each(tags, &tags->breserved_tags, 0, fn, priv, true);
-	bt_tags_for_each(tags, &tags->bitmap_tags, tags->nr_reserved_tags, fn, priv,
-			false);
+		bt_tags_for_each(tags, &tags->breserved_tags, fn, priv, true);
+	bt_tags_for_each(tags, &tags->bitmap_tags, fn, priv, false);
 }
 
 void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset,
@@ -529,124 +346,40 @@
 			continue;
 
 		if (tags->nr_reserved_tags)
-			bt_for_each(hctx, &tags->breserved_tags, 0, fn, priv, true);
-		bt_for_each(hctx, &tags->bitmap_tags, tags->nr_reserved_tags, fn, priv,
-		      false);
+			bt_for_each(hctx, &tags->breserved_tags, fn, priv, true);
+		bt_for_each(hctx, &tags->bitmap_tags, fn, priv, false);
 	}
 
 }
 
-static unsigned int bt_unused_tags(struct blk_mq_bitmap_tags *bt)
+static unsigned int bt_unused_tags(const struct sbitmap_queue *bt)
 {
-	unsigned int i, used;
-
-	for (i = 0, used = 0; i < bt->map_nr; i++) {
-		struct blk_align_bitmap *bm = &bt->map[i];
-
-		used += bitmap_weight(&bm->word, bm->depth);
-	}
-
-	return bt->depth - used;
+	return bt->sb.depth - sbitmap_weight(&bt->sb);
 }
 
-static void bt_update_count(struct blk_mq_bitmap_tags *bt,
-			    unsigned int depth)
+static int bt_alloc(struct sbitmap_queue *bt, unsigned int depth,
+		    bool round_robin, int node)
 {
-	unsigned int tags_per_word = 1U << bt->bits_per_word;
-	unsigned int map_depth = depth;
-
-	if (depth) {
-		int i;
-
-		for (i = 0; i < bt->map_nr; i++) {
-			bt->map[i].depth = min(map_depth, tags_per_word);
-			map_depth -= bt->map[i].depth;
-		}
-	}
-
-	bt->wake_cnt = BT_WAIT_BATCH;
-	if (bt->wake_cnt > depth / BT_WAIT_QUEUES)
-		bt->wake_cnt = max(1U, depth / BT_WAIT_QUEUES);
-
-	bt->depth = depth;
-}
-
-static int bt_alloc(struct blk_mq_bitmap_tags *bt, unsigned int depth,
-			int node, bool reserved)
-{
-	int i;
-
-	bt->bits_per_word = ilog2(BITS_PER_LONG);
-
-	/*
-	 * Depth can be zero for reserved tags, that's not a failure
-	 * condition.
-	 */
-	if (depth) {
-		unsigned int nr, tags_per_word;
-
-		tags_per_word = (1 << bt->bits_per_word);
-
-		/*
-		 * If the tag space is small, shrink the number of tags
-		 * per word so we spread over a few cachelines, at least.
-		 * If less than 4 tags, just forget about it, it's not
-		 * going to work optimally anyway.
-		 */
-		if (depth >= 4) {
-			while (tags_per_word * 4 > depth) {
-				bt->bits_per_word--;
-				tags_per_word = (1 << bt->bits_per_word);
-			}
-		}
-
-		nr = ALIGN(depth, tags_per_word) / tags_per_word;
-		bt->map = kzalloc_node(nr * sizeof(struct blk_align_bitmap),
-						GFP_KERNEL, node);
-		if (!bt->map)
-			return -ENOMEM;
-
-		bt->map_nr = nr;
-	}
-
-	bt->bs = kzalloc(BT_WAIT_QUEUES * sizeof(*bt->bs), GFP_KERNEL);
-	if (!bt->bs) {
-		kfree(bt->map);
-		bt->map = NULL;
-		return -ENOMEM;
-	}
-
-	bt_update_count(bt, depth);
-
-	for (i = 0; i < BT_WAIT_QUEUES; i++) {
-		init_waitqueue_head(&bt->bs[i].wait);
-		atomic_set(&bt->bs[i].wait_cnt, bt->wake_cnt);
-	}
-
-	return 0;
-}
-
-static void bt_free(struct blk_mq_bitmap_tags *bt)
-{
-	kfree(bt->map);
-	kfree(bt->bs);
+	return sbitmap_queue_init_node(bt, depth, -1, round_robin, GFP_KERNEL,
+				       node);
 }
 
 static struct blk_mq_tags *blk_mq_init_bitmap_tags(struct blk_mq_tags *tags,
 						   int node, int alloc_policy)
 {
 	unsigned int depth = tags->nr_tags - tags->nr_reserved_tags;
+	bool round_robin = alloc_policy == BLK_TAG_ALLOC_RR;
 
-	tags->alloc_policy = alloc_policy;
-
-	if (bt_alloc(&tags->bitmap_tags, depth, node, false))
-		goto enomem;
-	if (bt_alloc(&tags->breserved_tags, tags->nr_reserved_tags, node, true))
-		goto enomem;
+	if (bt_alloc(&tags->bitmap_tags, depth, round_robin, node))
+		goto free_tags;
+	if (bt_alloc(&tags->breserved_tags, tags->nr_reserved_tags, round_robin,
+		     node))
+		goto free_bitmap_tags;
 
 	return tags;
-enomem:
-	bt_free(&tags->bitmap_tags);
+free_bitmap_tags:
+	sbitmap_queue_free(&tags->bitmap_tags);
+free_tags:
 	kfree(tags);
 	return NULL;
 }
@@ -679,19 +412,12 @@
 
 void blk_mq_free_tags(struct blk_mq_tags *tags)
 {
-	bt_free(&tags->bitmap_tags);
-	bt_free(&tags->breserved_tags);
+	sbitmap_queue_free(&tags->bitmap_tags);
+	sbitmap_queue_free(&tags->breserved_tags);
 	free_cpumask_var(tags->cpumask);
 	kfree(tags);
 }
 
-void blk_mq_tag_init_last_tag(struct blk_mq_tags *tags, unsigned int *tag)
-{
-	unsigned int depth = tags->nr_tags - tags->nr_reserved_tags;
-
-	*tag = prandom_u32() % depth;
-}
-
 int blk_mq_tag_update_depth(struct blk_mq_tags *tags, unsigned int tdepth)
 {
 	tdepth -= tags->nr_reserved_tags;
@@ -702,7 +428,8 @@
 	 * Don't need (or can't) update reserved tags here, they remain
 	 * static and should never need resizing.
 	 */
-	bt_update_count(&tags->bitmap_tags, tdepth);
+	sbitmap_queue_resize(&tags->bitmap_tags, tdepth);
+
 	blk_mq_tag_wakeup_all(tags, false);
 	return 0;
 }
@@ -746,7 +473,7 @@
 	page += sprintf(page, "nr_tags=%u, reserved_tags=%u, "
 			"bits_per_word=%u\n",
 			tags->nr_tags, tags->nr_reserved_tags,
-			tags->bitmap_tags.bits_per_word);
+			1U << tags->bitmap_tags.sb.shift);
 
 	free = bt_unused_tags(&tags->bitmap_tags);
 	res = bt_unused_tags(&tags->breserved_tags);
diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h
index d468a79..09f4cc0 100644
--- a/block/blk-mq-tag.h
+++ b/block/blk-mq-tag.h
@@ -3,31 +3,6 @@
 
 #include "blk-mq.h"
 
-enum {
-	BT_WAIT_QUEUES	= 8,
-	BT_WAIT_BATCH	= 8,
-};
-
-struct bt_wait_state {
-	atomic_t wait_cnt;
-	wait_queue_head_t wait;
-} ____cacheline_aligned_in_smp;
-
-#define TAG_TO_INDEX(bt, tag)	((tag) >> (bt)->bits_per_word)
-#define TAG_TO_BIT(bt, tag)	((tag) & ((1 << (bt)->bits_per_word) - 1))
-
-struct blk_mq_bitmap_tags {
-	unsigned int depth;
-	unsigned int wake_cnt;
-	unsigned int bits_per_word;
-
-	unsigned int map_nr;
-	struct blk_align_bitmap *map;
-
-	atomic_t wake_index;
-	struct bt_wait_state *bs;
-};
-
 /*
  * Tag address space map.
  */
@@ -37,13 +12,12 @@
 
 	atomic_t active_queues;
 
-	struct blk_mq_bitmap_tags bitmap_tags;
-	struct blk_mq_bitmap_tags breserved_tags;
+	struct sbitmap_queue bitmap_tags;
+	struct sbitmap_queue breserved_tags;
 
 	struct request **rqs;
 	struct list_head page_list;
 
-	int alloc_policy;
 	cpumask_var_t cpumask;
 };
 
@@ -52,15 +26,23 @@
 extern void blk_mq_free_tags(struct blk_mq_tags *tags);
 
 extern unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data);
-extern void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, unsigned int tag, unsigned int *last_tag);
+extern void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
+			   unsigned int tag);
 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);
 void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn,
 		void *priv);
 
+static inline struct sbq_wait_state *bt_wait_ptr(struct sbitmap_queue *bt,
+						 struct blk_mq_hw_ctx *hctx)
+{
+	if (!hctx)
+		return &bt->ws[0];
+	return sbq_wait_ptr(bt, &hctx->wait_index);
+}
+
 enum {
 	BLK_MQ_TAG_CACHE_MIN	= 1,
 	BLK_MQ_TAG_CACHE_MAX	= 64,
diff --git a/block/blk-mq.c b/block/blk-mq.c
index c207fa9..dc5f47f 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -22,6 +22,7 @@
 #include <linux/sched/sysctl.h>
 #include <linux/delay.h>
 #include <linux/crash_dump.h>
+#include <linux/prefetch.h>
 
 #include <trace/events/block.h>
 
@@ -33,49 +34,28 @@
 static DEFINE_MUTEX(all_q_mutex);
 static LIST_HEAD(all_q_list);
 
-static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx);
-
 /*
  * Check if any of the ctx's have pending work in this hardware queue
  */
 static bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx)
 {
-	unsigned int i;
-
-	for (i = 0; i < hctx->ctx_map.size; i++)
-		if (hctx->ctx_map.map[i].word)
-			return true;
-
-	return false;
+	return sbitmap_any_bit_set(&hctx->ctx_map);
 }
 
-static inline struct blk_align_bitmap *get_bm(struct blk_mq_hw_ctx *hctx,
-					      struct blk_mq_ctx *ctx)
-{
-	return &hctx->ctx_map.map[ctx->index_hw / hctx->ctx_map.bits_per_word];
-}
-
-#define CTX_TO_BIT(hctx, ctx)	\
-	((ctx)->index_hw & ((hctx)->ctx_map.bits_per_word - 1))
-
 /*
  * Mark this ctx as having pending work in this hardware queue
  */
 static void blk_mq_hctx_mark_pending(struct blk_mq_hw_ctx *hctx,
 				     struct blk_mq_ctx *ctx)
 {
-	struct blk_align_bitmap *bm = get_bm(hctx, ctx);
-
-	if (!test_bit(CTX_TO_BIT(hctx, ctx), &bm->word))
-		set_bit(CTX_TO_BIT(hctx, ctx), &bm->word);
+	if (!sbitmap_test_bit(&hctx->ctx_map, ctx->index_hw))
+		sbitmap_set_bit(&hctx->ctx_map, ctx->index_hw);
 }
 
 static void blk_mq_hctx_clear_pending(struct blk_mq_hw_ctx *hctx,
 				      struct blk_mq_ctx *ctx)
 {
-	struct blk_align_bitmap *bm = get_bm(hctx, ctx);
-
-	clear_bit(CTX_TO_BIT(hctx, ctx), &bm->word);
+	sbitmap_clear_bit(&hctx->ctx_map, ctx->index_hw);
 }
 
 void blk_mq_freeze_queue_start(struct request_queue *q)
@@ -246,19 +226,9 @@
 	ctx = blk_mq_get_ctx(q);
 	hctx = q->mq_ops->map_queue(q, ctx->cpu);
 	blk_mq_set_alloc_data(&alloc_data, q, flags, ctx, hctx);
-
 	rq = __blk_mq_alloc_request(&alloc_data, rw, 0);
-	if (!rq && !(flags & BLK_MQ_REQ_NOWAIT)) {
-		__blk_mq_run_hw_queue(hctx);
-		blk_mq_put_ctx(ctx);
-
-		ctx = blk_mq_get_ctx(q);
-		hctx = q->mq_ops->map_queue(q, ctx->cpu);
-		blk_mq_set_alloc_data(&alloc_data, q, flags, ctx, hctx);
-		rq =  __blk_mq_alloc_request(&alloc_data, rw, 0);
-		ctx = alloc_data.ctx;
-	}
 	blk_mq_put_ctx(ctx);
+
 	if (!rq) {
 		blk_queue_exit(q);
 		return ERR_PTR(-EWOULDBLOCK);
@@ -333,7 +303,7 @@
 	rq->cmd_flags = 0;
 
 	clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags);
-	blk_mq_put_tag(hctx, tag, &ctx->last_tag);
+	blk_mq_put_tag(hctx, ctx, tag);
 	blk_queue_exit(q);
 }
 
@@ -513,7 +483,7 @@
 static void blk_mq_requeue_work(struct work_struct *work)
 {
 	struct request_queue *q =
-		container_of(work, struct request_queue, requeue_work);
+		container_of(work, struct request_queue, requeue_work.work);
 	LIST_HEAD(rq_list);
 	struct request *rq, *next;
 	unsigned long flags;
@@ -568,16 +538,24 @@
 
 void blk_mq_cancel_requeue_work(struct request_queue *q)
 {
-	cancel_work_sync(&q->requeue_work);
+	cancel_delayed_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);
+	kblockd_schedule_delayed_work(&q->requeue_work, 0);
 }
 EXPORT_SYMBOL(blk_mq_kick_requeue_list);
 
+void blk_mq_delay_kick_requeue_list(struct request_queue *q,
+				    unsigned long msecs)
+{
+	kblockd_schedule_delayed_work(&q->requeue_work,
+				      msecs_to_jiffies(msecs));
+}
+EXPORT_SYMBOL(blk_mq_delay_kick_requeue_list);
+
 void blk_mq_abort_requeue_list(struct request_queue *q)
 {
 	unsigned long flags;
@@ -600,8 +578,10 @@
 
 struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag)
 {
-	if (tag < tags->nr_tags)
+	if (tag < tags->nr_tags) {
+		prefetch(tags->rqs[tag]);
 		return tags->rqs[tag];
+	}
 
 	return NULL;
 }
@@ -756,38 +736,44 @@
 	return false;
 }
 
+struct flush_busy_ctx_data {
+	struct blk_mq_hw_ctx *hctx;
+	struct list_head *list;
+};
+
+static bool flush_busy_ctx(struct sbitmap *sb, unsigned int bitnr, void *data)
+{
+	struct flush_busy_ctx_data *flush_data = data;
+	struct blk_mq_hw_ctx *hctx = flush_data->hctx;
+	struct blk_mq_ctx *ctx = hctx->ctxs[bitnr];
+
+	sbitmap_clear_bit(sb, bitnr);
+	spin_lock(&ctx->lock);
+	list_splice_tail_init(&ctx->rq_list, flush_data->list);
+	spin_unlock(&ctx->lock);
+	return true;
+}
+
 /*
  * Process software queues that have been marked busy, splicing them
  * to the for-dispatch
  */
 static void flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list)
 {
-	struct blk_mq_ctx *ctx;
-	int i;
+	struct flush_busy_ctx_data data = {
+		.hctx = hctx,
+		.list = list,
+	};
 
-	for (i = 0; i < hctx->ctx_map.size; i++) {
-		struct blk_align_bitmap *bm = &hctx->ctx_map.map[i];
-		unsigned int off, bit;
+	sbitmap_for_each_set(&hctx->ctx_map, flush_busy_ctx, &data);
+}
 
-		if (!bm->word)
-			continue;
+static inline unsigned int queued_to_index(unsigned int queued)
+{
+	if (!queued)
+		return 0;
 
-		bit = 0;
-		off = i * hctx->ctx_map.bits_per_word;
-		do {
-			bit = find_next_bit(&bm->word, bm->depth, bit);
-			if (bit >= bm->depth)
-				break;
-
-			ctx = hctx->ctxs[bit + off];
-			clear_bit(bit, &bm->word);
-			spin_lock(&ctx->lock);
-			list_splice_tail_init(&ctx->rq_list, list);
-			spin_unlock(&ctx->lock);
-
-			bit++;
-		} while (1);
-	}
+	return min(BLK_MQ_MAX_DISPATCH_ORDER - 1, ilog2(queued) + 1);
 }
 
 /*
@@ -878,10 +864,7 @@
 			dptr = &driver_list;
 	}
 
-	if (!queued)
-		hctx->dispatched[0]++;
-	else if (queued < (1 << (BLK_MQ_MAX_DISPATCH_ORDER - 1)))
-		hctx->dispatched[ilog2(queued) + 1]++;
+	hctx->dispatched[queued_to_index(queued)]++;
 
 	/*
 	 * Any items that need requeuing? Stuff them into hctx->dispatch,
@@ -937,7 +920,7 @@
 	    !blk_mq_hw_queue_mapped(hctx)))
 		return;
 
-	if (!async) {
+	if (!async && !(hctx->flags & BLK_MQ_F_BLOCKING)) {
 		int cpu = get_cpu();
 		if (cpumask_test_cpu(cpu, hctx->cpumask)) {
 			__blk_mq_run_hw_queue(hctx);
@@ -948,8 +931,7 @@
 		put_cpu();
 	}
 
-	kblockd_schedule_delayed_work_on(blk_mq_hctx_next_cpu(hctx),
-			&hctx->run_work, 0);
+	kblockd_schedule_work_on(blk_mq_hctx_next_cpu(hctx), &hctx->run_work);
 }
 
 void blk_mq_run_hw_queues(struct request_queue *q, bool async)
@@ -970,7 +952,7 @@
 
 void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx)
 {
-	cancel_delayed_work(&hctx->run_work);
+	cancel_work(&hctx->run_work);
 	cancel_delayed_work(&hctx->delay_work);
 	set_bit(BLK_MQ_S_STOPPED, &hctx->state);
 }
@@ -1023,7 +1005,7 @@
 {
 	struct blk_mq_hw_ctx *hctx;
 
-	hctx = container_of(work, struct blk_mq_hw_ctx, run_work.work);
+	hctx = container_of(work, struct blk_mq_hw_ctx, run_work);
 
 	__blk_mq_run_hw_queue(hctx);
 }
@@ -1240,20 +1222,8 @@
 		op_flags |= REQ_SYNC;
 
 	trace_block_getrq(q, bio, op);
-	blk_mq_set_alloc_data(&alloc_data, q, BLK_MQ_REQ_NOWAIT, ctx, hctx);
+	blk_mq_set_alloc_data(&alloc_data, q, 0, ctx, hctx);
 	rq = __blk_mq_alloc_request(&alloc_data, op, op_flags);
-	if (unlikely(!rq)) {
-		__blk_mq_run_hw_queue(hctx);
-		blk_mq_put_ctx(ctx);
-		trace_block_sleeprq(q, bio, op);
-
-		ctx = blk_mq_get_ctx(q);
-		hctx = q->mq_ops->map_queue(q, ctx->cpu);
-		blk_mq_set_alloc_data(&alloc_data, q, 0, ctx, hctx);
-		rq = __blk_mq_alloc_request(&alloc_data, op, op_flags);
-		ctx = alloc_data.ctx;
-		hctx = alloc_data.hctx;
-	}
 
 	hctx->queued++;
 	data->hctx = hctx;
@@ -1606,32 +1576,6 @@
 	return NULL;
 }
 
-static void blk_mq_free_bitmap(struct blk_mq_ctxmap *bitmap)
-{
-	kfree(bitmap->map);
-}
-
-static int blk_mq_alloc_bitmap(struct blk_mq_ctxmap *bitmap, int node)
-{
-	unsigned int bpw = 8, total, num_maps, i;
-
-	bitmap->bits_per_word = bpw;
-
-	num_maps = ALIGN(nr_cpu_ids, bpw) / bpw;
-	bitmap->map = kzalloc_node(num_maps * sizeof(struct blk_align_bitmap),
-					GFP_KERNEL, node);
-	if (!bitmap->map)
-		return -ENOMEM;
-
-	total = nr_cpu_ids;
-	for (i = 0; i < num_maps; i++) {
-		bitmap->map[i].depth = min(total, bitmap->bits_per_word);
-		total -= bitmap->map[i].depth;
-	}
-
-	return 0;
-}
-
 /*
  * 'cpu' is going away. splice any existing rq_list entries from this
  * software queue to the hw queue dispatch list, and ensure that it
@@ -1697,7 +1641,7 @@
 
 	blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier);
 	blk_free_flush_queue(hctx->fq);
-	blk_mq_free_bitmap(&hctx->ctx_map);
+	sbitmap_free(&hctx->ctx_map);
 }
 
 static void blk_mq_exit_hw_queues(struct request_queue *q,
@@ -1734,7 +1678,7 @@
 	if (node == NUMA_NO_NODE)
 		node = hctx->numa_node = set->numa_node;
 
-	INIT_DELAYED_WORK(&hctx->run_work, blk_mq_run_work_fn);
+	INIT_WORK(&hctx->run_work, blk_mq_run_work_fn);
 	INIT_DELAYED_WORK(&hctx->delay_work, blk_mq_delay_work_fn);
 	spin_lock_init(&hctx->lock);
 	INIT_LIST_HEAD(&hctx->dispatch);
@@ -1757,7 +1701,8 @@
 	if (!hctx->ctxs)
 		goto unregister_cpu_notifier;
 
-	if (blk_mq_alloc_bitmap(&hctx->ctx_map, node))
+	if (sbitmap_init_node(&hctx->ctx_map, nr_cpu_ids, ilog2(8), GFP_KERNEL,
+			      node))
 		goto free_ctxs;
 
 	hctx->nr_ctx = 0;
@@ -1784,7 +1729,7 @@
 	if (set->ops->exit_hctx)
 		set->ops->exit_hctx(hctx, hctx_idx);
  free_bitmap:
-	blk_mq_free_bitmap(&hctx->ctx_map);
+	sbitmap_free(&hctx->ctx_map);
  free_ctxs:
 	kfree(hctx->ctxs);
  unregister_cpu_notifier:
@@ -1860,8 +1805,6 @@
 	mutex_unlock(&q->sysfs_lock);
 
 	queue_for_each_hw_ctx(q, hctx, i) {
-		struct blk_mq_ctxmap *map = &hctx->ctx_map;
-
 		/*
 		 * If no software queues are mapped to this hardware queue,
 		 * disable it and free the request entries.
@@ -1887,7 +1830,7 @@
 		 * This is more accurate and more efficient than looping
 		 * over all possibly mapped software queues.
 		 */
-		map->size = DIV_ROUND_UP(hctx->nr_ctx, map->bits_per_word);
+		sbitmap_resize(&hctx->ctx_map, hctx->nr_ctx);
 
 		/*
 		 * Initialize batch roundrobin counts
@@ -2094,7 +2037,7 @@
 
 	q->sg_reserved_size = INT_MAX;
 
-	INIT_WORK(&q->requeue_work, blk_mq_requeue_work);
+	INIT_DELAYED_WORK(&q->requeue_work, blk_mq_requeue_work);
 	INIT_LIST_HEAD(&q->requeue_list);
 	spin_lock_init(&q->requeue_lock);
 
diff --git a/block/blk-mq.h b/block/blk-mq.h
index 9087b11..9b15d2e 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -12,8 +12,6 @@
 	unsigned int		cpu;
 	unsigned int		index_hw;
 
-	unsigned int		last_tag ____cacheline_aligned_in_smp;
-
 	/* incremented at dispatch time */
 	unsigned long		rq_dispatched[2];
 	unsigned long		rq_merged;
@@ -63,15 +61,6 @@
 
 void blk_mq_release(struct request_queue *q);
 
-/*
- * Basic implementation of sparser bitmap, allowing the user to spread
- * the bits over more cachelines.
- */
-struct blk_align_bitmap {
-	unsigned long word;
-	unsigned long depth;
-} ____cacheline_aligned_in_smp;
-
 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
 					   unsigned int cpu)
 {
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index f87a7e7..9cc8d7c 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -704,7 +704,7 @@
 	kobject_uevent(&q->kobj, KOBJ_ADD);
 
 	if (q->mq_ops)
-		blk_mq_register_disk(disk);
+		blk_mq_register_dev(dev, q);
 
 	if (!q->request_fn)
 		return 0;
@@ -729,7 +729,7 @@
 		return;
 
 	if (q->mq_ops)
-		blk_mq_unregister_disk(disk);
+		blk_mq_unregister_dev(disk_to_dev(disk), q);
 
 	if (q->request_fn)
 		elv_unregister_queue(q);
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index cc2f6db..5e24d88 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -3042,7 +3042,6 @@
 	if (ktime_get_ns() < rq->fifo_time)
 		rq = NULL;
 
-	cfq_log_cfqq(cfqq->cfqd, cfqq, "fifo=%p", rq);
 	return rq;
 }
 
@@ -3420,6 +3419,9 @@
 {
 	unsigned int max_dispatch;
 
+	if (cfq_cfqq_must_dispatch(cfqq))
+		return true;
+
 	/*
 	 * Drain async requests before we start sync IO
 	 */
@@ -3511,15 +3513,20 @@
 
 	BUG_ON(RB_EMPTY_ROOT(&cfqq->sort_list));
 
+	rq = cfq_check_fifo(cfqq);
+	if (rq)
+		cfq_mark_cfqq_must_dispatch(cfqq);
+
 	if (!cfq_may_dispatch(cfqd, cfqq))
 		return false;
 
 	/*
 	 * follow expired path, else get first next available
 	 */
-	rq = cfq_check_fifo(cfqq);
 	if (!rq)
 		rq = cfqq->next_rq;
+	else
+		cfq_log_cfqq(cfqq->cfqd, cfqq, "fifo=%p", rq);
 
 	/*
 	 * insert request into driver dispatch list
@@ -3989,7 +3996,7 @@
 	 * if the new request is sync, but the currently running queue is
 	 * not, let the sync request have priority.
 	 */
-	if (rq_is_sync(rq) && !cfq_cfqq_sync(cfqq))
+	if (rq_is_sync(rq) && !cfq_cfqq_sync(cfqq) && !cfq_cfqq_must_dispatch(cfqq))
 		return true;
 
 	/*
diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index 2aca98e..88c4685 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -3686,7 +3686,7 @@
 	return -ENODEV;
 }
 
-void mtip_block_release(struct gendisk *disk, fmode_t mode)
+static void mtip_block_release(struct gendisk *disk, fmode_t mode)
 {
 }
 
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index a9e3980..ccfcfc1 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -34,33 +34,29 @@
 #include <linux/kthread.h>
 #include <linux/types.h>
 #include <linux/debugfs.h>
+#include <linux/blk-mq.h>
 
 #include <asm/uaccess.h>
 #include <asm/types.h>
 
 #include <linux/nbd.h>
 
+#define NBD_TIMEDOUT			0
+#define NBD_DISCONNECT_REQUESTED	1
+
 struct nbd_device {
 	u32 flags;
+	unsigned long runtime_flags;
 	struct socket * sock;	/* If == NULL, device is not ready, yet	*/
 	int magic;
 
-	spinlock_t queue_lock;
-	struct list_head queue_head;	/* Requests waiting result */
-	struct request *active_req;
-	wait_queue_head_t active_wq;
-	struct list_head waiting_queue;	/* Requests to be sent */
-	wait_queue_head_t waiting_wq;
+	struct blk_mq_tag_set tag_set;
 
 	struct mutex tx_lock;
 	struct gendisk *disk;
 	int blksize;
 	loff_t bytesize;
-	int xmit_timeout;
-	bool timedout;
-	bool disconnect; /* a disconnect has been requested by user */
 
-	struct timer_list timeout_timer;
 	/* protects initialization and shutdown of the socket */
 	spinlock_t sock_lock;
 	struct task_struct *task_recv;
@@ -71,6 +67,11 @@
 #endif
 };
 
+struct nbd_cmd {
+	struct nbd_device *nbd;
+	struct list_head list;
+};
+
 #if IS_ENABLED(CONFIG_DEBUG_FS)
 static struct dentry *nbd_dbg_dir;
 #endif
@@ -83,18 +84,6 @@
 static struct nbd_device *nbd_dev;
 static int max_part;
 
-/*
- * Use just one lock (or at most 1 per NIC). Two arguments for this:
- * 1. Each NIC is essentially a synchronization point for all servers
- *    accessed through that NIC so there's no need to have more locks
- *    than NICs anyway.
- * 2. More locks lead to more "Dirty cache line bouncing" which will slow
- *    down each lock to the point where they're actually slower than just
- *    a single lock.
- * Thanks go to Jens Axboe and Al Viro for their LKML emails explaining this!
- */
-static DEFINE_SPINLOCK(nbd_lock);
-
 static inline struct device *nbd_to_dev(struct nbd_device *nbd)
 {
 	return disk_to_dev(nbd->disk);
@@ -153,18 +142,16 @@
 	return 0;
 }
 
-static void nbd_end_request(struct nbd_device *nbd, struct request *req)
+static void nbd_end_request(struct nbd_cmd *cmd)
 {
+	struct nbd_device *nbd = cmd->nbd;
+	struct request *req = blk_mq_rq_from_pdu(cmd);
 	int error = req->errors ? -EIO : 0;
-	struct request_queue *q = req->q;
-	unsigned long flags;
 
-	dev_dbg(nbd_to_dev(nbd), "request %p: %s\n", req,
+	dev_dbg(nbd_to_dev(nbd), "request %p: %s\n", cmd,
 		error ? "failed" : "done");
 
-	spin_lock_irqsave(q->queue_lock, flags);
-	__blk_end_request_all(req, error);
-	spin_unlock_irqrestore(q->queue_lock, flags);
+	blk_mq_complete_request(req, error);
 }
 
 /*
@@ -172,40 +159,49 @@
  */
 static void sock_shutdown(struct nbd_device *nbd)
 {
-	spin_lock_irq(&nbd->sock_lock);
+	struct socket *sock;
+
+	spin_lock(&nbd->sock_lock);
 
 	if (!nbd->sock) {
 		spin_unlock_irq(&nbd->sock_lock);
 		return;
 	}
 
+	sock = nbd->sock;
 	dev_warn(disk_to_dev(nbd->disk), "shutting down socket\n");
-	kernel_sock_shutdown(nbd->sock, SHUT_RDWR);
-	sockfd_put(nbd->sock);
 	nbd->sock = NULL;
-	spin_unlock_irq(&nbd->sock_lock);
+	spin_unlock(&nbd->sock_lock);
 
-	del_timer(&nbd->timeout_timer);
+	kernel_sock_shutdown(sock, SHUT_RDWR);
+	sockfd_put(sock);
 }
 
-static void nbd_xmit_timeout(unsigned long arg)
+static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req,
+						 bool reserved)
 {
-	struct nbd_device *nbd = (struct nbd_device *)arg;
-	unsigned long flags;
+	struct nbd_cmd *cmd = blk_mq_rq_to_pdu(req);
+	struct nbd_device *nbd = cmd->nbd;
+	struct socket *sock = NULL;
 
-	if (list_empty(&nbd->queue_head))
-		return;
+	spin_lock(&nbd->sock_lock);
 
-	spin_lock_irqsave(&nbd->sock_lock, flags);
+	set_bit(NBD_TIMEDOUT, &nbd->runtime_flags);
 
-	nbd->timedout = true;
+	if (nbd->sock) {
+		sock = nbd->sock;
+		get_file(sock->file);
+	}
 
-	if (nbd->sock)
-		kernel_sock_shutdown(nbd->sock, SHUT_RDWR);
+	spin_unlock(&nbd->sock_lock);
+	if (sock) {
+		kernel_sock_shutdown(sock, SHUT_RDWR);
+		sockfd_put(sock);
+	}
 
-	spin_unlock_irqrestore(&nbd->sock_lock, flags);
-
+	req->errors++;
 	dev_err(nbd_to_dev(nbd), "Connection timed out, shutting down connection\n");
+	return BLK_EH_HANDLED;
 }
 
 /*
@@ -255,9 +251,6 @@
 
 	tsk_restore_flags(current, pflags, PF_MEMALLOC);
 
-	if (!send && nbd->xmit_timeout)
-		mod_timer(&nbd->timeout_timer, jiffies + nbd->xmit_timeout);
-
 	return result;
 }
 
@@ -273,8 +266,9 @@
 }
 
 /* always call with the tx_lock held */
-static int nbd_send_req(struct nbd_device *nbd, struct request *req)
+static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd)
 {
+	struct request *req = blk_mq_rq_from_pdu(cmd);
 	int result, flags;
 	struct nbd_request request;
 	unsigned long size = blk_rq_bytes(req);
@@ -298,10 +292,10 @@
 		request.from = cpu_to_be64((u64)blk_rq_pos(req) << 9);
 		request.len = htonl(size);
 	}
-	memcpy(request.handle, &req, sizeof(req));
+	memcpy(request.handle, &req->tag, sizeof(req->tag));
 
 	dev_dbg(nbd_to_dev(nbd), "request %p: sending control (%s@%llu,%uB)\n",
-		req, nbdcmd_to_ascii(type),
+		cmd, nbdcmd_to_ascii(type),
 		(unsigned long long)blk_rq_pos(req) << 9, blk_rq_bytes(req));
 	result = sock_xmit(nbd, 1, &request, sizeof(request),
 			(type == NBD_CMD_WRITE) ? MSG_MORE : 0);
@@ -323,7 +317,7 @@
 			if (!rq_iter_last(bvec, iter))
 				flags = MSG_MORE;
 			dev_dbg(nbd_to_dev(nbd), "request %p: sending %d bytes data\n",
-				req, bvec.bv_len);
+				cmd, bvec.bv_len);
 			result = sock_send_bvec(nbd, &bvec, flags);
 			if (result <= 0) {
 				dev_err(disk_to_dev(nbd->disk),
@@ -336,29 +330,6 @@
 	return 0;
 }
 
-static struct request *nbd_find_request(struct nbd_device *nbd,
-					struct request *xreq)
-{
-	struct request *req, *tmp;
-	int err;
-
-	err = wait_event_interruptible(nbd->active_wq, nbd->active_req != xreq);
-	if (unlikely(err))
-		return ERR_PTR(err);
-
-	spin_lock(&nbd->queue_lock);
-	list_for_each_entry_safe(req, tmp, &nbd->queue_head, queuelist) {
-		if (req != xreq)
-			continue;
-		list_del_init(&req->queuelist);
-		spin_unlock(&nbd->queue_lock);
-		return req;
-	}
-	spin_unlock(&nbd->queue_lock);
-
-	return ERR_PTR(-ENOENT);
-}
-
 static inline int sock_recv_bvec(struct nbd_device *nbd, struct bio_vec *bvec)
 {
 	int result;
@@ -370,11 +341,14 @@
 }
 
 /* NULL returned = something went wrong, inform userspace */
-static struct request *nbd_read_stat(struct nbd_device *nbd)
+static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd)
 {
 	int result;
 	struct nbd_reply reply;
-	struct request *req;
+	struct nbd_cmd *cmd;
+	struct request *req = NULL;
+	u16 hwq;
+	int tag;
 
 	reply.magic = 0;
 	result = sock_xmit(nbd, 0, &reply, sizeof(reply), MSG_WAITALL);
@@ -390,25 +364,27 @@
 		return ERR_PTR(-EPROTO);
 	}
 
-	req = nbd_find_request(nbd, *(struct request **)reply.handle);
-	if (IS_ERR(req)) {
-		result = PTR_ERR(req);
-		if (result != -ENOENT)
-			return ERR_PTR(result);
+	memcpy(&tag, reply.handle, sizeof(int));
 
-		dev_err(disk_to_dev(nbd->disk), "Unexpected reply (%p)\n",
-			reply.handle);
-		return ERR_PTR(-EBADR);
+	hwq = blk_mq_unique_tag_to_hwq(tag);
+	if (hwq < nbd->tag_set.nr_hw_queues)
+		req = blk_mq_tag_to_rq(nbd->tag_set.tags[hwq],
+				       blk_mq_unique_tag_to_tag(tag));
+	if (!req || !blk_mq_request_started(req)) {
+		dev_err(disk_to_dev(nbd->disk), "Unexpected reply (%d) %p\n",
+			tag, req);
+		return ERR_PTR(-ENOENT);
 	}
+	cmd = blk_mq_rq_to_pdu(req);
 
 	if (ntohl(reply.error)) {
 		dev_err(disk_to_dev(nbd->disk), "Other side returned error (%d)\n",
 			ntohl(reply.error));
 		req->errors++;
-		return req;
+		return cmd;
 	}
 
-	dev_dbg(nbd_to_dev(nbd), "request %p: got reply\n", req);
+	dev_dbg(nbd_to_dev(nbd), "request %p: got reply\n", cmd);
 	if (rq_data_dir(req) != WRITE) {
 		struct req_iterator iter;
 		struct bio_vec bvec;
@@ -419,13 +395,13 @@
 				dev_err(disk_to_dev(nbd->disk), "Receive data failed (result %d)\n",
 					result);
 				req->errors++;
-				return req;
+				return cmd;
 			}
 			dev_dbg(nbd_to_dev(nbd), "request %p: got %d bytes data\n",
-				req, bvec.bv_len);
+				cmd, bvec.bv_len);
 		}
 	}
-	return req;
+	return cmd;
 }
 
 static ssize_t pid_show(struct device *dev,
@@ -444,7 +420,7 @@
 
 static int nbd_thread_recv(struct nbd_device *nbd, struct block_device *bdev)
 {
-	struct request *req;
+	struct nbd_cmd *cmd;
 	int ret;
 
 	BUG_ON(nbd->magic != NBD_MAGIC);
@@ -460,13 +436,13 @@
 	nbd_size_update(nbd, bdev);
 
 	while (1) {
-		req = nbd_read_stat(nbd);
-		if (IS_ERR(req)) {
-			ret = PTR_ERR(req);
+		cmd = nbd_read_stat(nbd);
+		if (IS_ERR(cmd)) {
+			ret = PTR_ERR(cmd);
 			break;
 		}
 
-		nbd_end_request(nbd, req);
+		nbd_end_request(cmd);
 	}
 
 	nbd_size_clear(nbd, bdev);
@@ -475,44 +451,37 @@
 	return ret;
 }
 
+static void nbd_clear_req(struct request *req, void *data, bool reserved)
+{
+	struct nbd_cmd *cmd;
+
+	if (!blk_mq_request_started(req))
+		return;
+	cmd = blk_mq_rq_to_pdu(req);
+	req->errors++;
+	nbd_end_request(cmd);
+}
+
 static void nbd_clear_que(struct nbd_device *nbd)
 {
-	struct request *req;
-
 	BUG_ON(nbd->magic != NBD_MAGIC);
 
 	/*
 	 * Because we have set nbd->sock to NULL under the tx_lock, all
-	 * modifications to the list must have completed by now.  For
-	 * the same reason, the active_req must be NULL.
-	 *
-	 * As a consequence, we don't need to take the spin lock while
-	 * purging the list here.
+	 * modifications to the list must have completed by now.
 	 */
 	BUG_ON(nbd->sock);
-	BUG_ON(nbd->active_req);
 
-	while (!list_empty(&nbd->queue_head)) {
-		req = list_entry(nbd->queue_head.next, struct request,
-				 queuelist);
-		list_del_init(&req->queuelist);
-		req->errors++;
-		nbd_end_request(nbd, req);
-	}
-
-	while (!list_empty(&nbd->waiting_queue)) {
-		req = list_entry(nbd->waiting_queue.next, struct request,
-				 queuelist);
-		list_del_init(&req->queuelist);
-		req->errors++;
-		nbd_end_request(nbd, req);
-	}
+	blk_mq_tagset_busy_iter(&nbd->tag_set, nbd_clear_req, NULL);
 	dev_dbg(disk_to_dev(nbd->disk), "queue cleared\n");
 }
 
 
-static void nbd_handle_req(struct nbd_device *nbd, struct request *req)
+static void nbd_handle_cmd(struct nbd_cmd *cmd)
 {
+	struct request *req = blk_mq_rq_from_pdu(cmd);
+	struct nbd_device *nbd = cmd->nbd;
+
 	if (req->cmd_type != REQ_TYPE_FS)
 		goto error_out;
 
@@ -526,6 +495,7 @@
 	req->errors = 0;
 
 	mutex_lock(&nbd->tx_lock);
+	nbd->task_send = current;
 	if (unlikely(!nbd->sock)) {
 		mutex_unlock(&nbd->tx_lock);
 		dev_err(disk_to_dev(nbd->disk),
@@ -533,106 +503,30 @@
 		goto error_out;
 	}
 
-	nbd->active_req = req;
-
-	if (nbd->xmit_timeout && list_empty_careful(&nbd->queue_head))
-		mod_timer(&nbd->timeout_timer, jiffies + nbd->xmit_timeout);
-
-	if (nbd_send_req(nbd, req) != 0) {
+	if (nbd_send_cmd(nbd, cmd) != 0) {
 		dev_err(disk_to_dev(nbd->disk), "Request send failed\n");
 		req->errors++;
-		nbd_end_request(nbd, req);
-	} else {
-		spin_lock(&nbd->queue_lock);
-		list_add_tail(&req->queuelist, &nbd->queue_head);
-		spin_unlock(&nbd->queue_lock);
+		nbd_end_request(cmd);
 	}
 
-	nbd->active_req = NULL;
+	nbd->task_send = NULL;
 	mutex_unlock(&nbd->tx_lock);
-	wake_up_all(&nbd->active_wq);
 
 	return;
 
 error_out:
 	req->errors++;
-	nbd_end_request(nbd, req);
+	nbd_end_request(cmd);
 }
 
-static int nbd_thread_send(void *data)
+static int nbd_queue_rq(struct blk_mq_hw_ctx *hctx,
+			const struct blk_mq_queue_data *bd)
 {
-	struct nbd_device *nbd = data;
-	struct request *req;
+	struct nbd_cmd *cmd = blk_mq_rq_to_pdu(bd->rq);
 
-	nbd->task_send = current;
-
-	set_user_nice(current, MIN_NICE);
-	while (!kthread_should_stop() || !list_empty(&nbd->waiting_queue)) {
-		/* wait for something to do */
-		wait_event_interruptible(nbd->waiting_wq,
-					 kthread_should_stop() ||
-					 !list_empty(&nbd->waiting_queue));
-
-		/* extract request */
-		if (list_empty(&nbd->waiting_queue))
-			continue;
-
-		spin_lock_irq(&nbd->queue_lock);
-		req = list_entry(nbd->waiting_queue.next, struct request,
-				 queuelist);
-		list_del_init(&req->queuelist);
-		spin_unlock_irq(&nbd->queue_lock);
-
-		/* handle request */
-		nbd_handle_req(nbd, req);
-	}
-
-	nbd->task_send = NULL;
-
-	return 0;
-}
-
-/*
- * We always wait for result of write, for now. It would be nice to make it optional
- * in future
- * if ((rq_data_dir(req) == WRITE) && (nbd->flags & NBD_WRITE_NOCHK))
- *   { printk( "Warning: Ignoring result!\n"); nbd_end_request( req ); }
- */
-
-static void nbd_request_handler(struct request_queue *q)
-		__releases(q->queue_lock) __acquires(q->queue_lock)
-{
-	struct request *req;
-	
-	while ((req = blk_fetch_request(q)) != NULL) {
-		struct nbd_device *nbd;
-
-		spin_unlock_irq(q->queue_lock);
-
-		nbd = req->rq_disk->private_data;
-
-		BUG_ON(nbd->magic != NBD_MAGIC);
-
-		dev_dbg(nbd_to_dev(nbd), "request %p: dequeued (flags=%x)\n",
-			req, req->cmd_type);
-
-		if (unlikely(!nbd->sock)) {
-			dev_err_ratelimited(disk_to_dev(nbd->disk),
-					    "Attempted send on closed socket\n");
-			req->errors++;
-			nbd_end_request(nbd, req);
-			spin_lock_irq(q->queue_lock);
-			continue;
-		}
-
-		spin_lock_irq(&nbd->queue_lock);
-		list_add_tail(&req->queuelist, &nbd->waiting_queue);
-		spin_unlock_irq(&nbd->queue_lock);
-
-		wake_up(&nbd->waiting_wq);
-
-		spin_lock_irq(q->queue_lock);
-	}
+	blk_mq_start_request(bd->rq);
+	nbd_handle_cmd(cmd);
+	return BLK_MQ_RQ_QUEUE_OK;
 }
 
 static int nbd_set_socket(struct nbd_device *nbd, struct socket *sock)
@@ -657,15 +551,13 @@
 /* Reset all properties of an NBD device */
 static void nbd_reset(struct nbd_device *nbd)
 {
-	nbd->disconnect = false;
-	nbd->timedout = false;
+	nbd->runtime_flags = 0;
 	nbd->blksize = 1024;
 	nbd->bytesize = 0;
 	set_capacity(nbd->disk, 0);
 	nbd->flags = 0;
-	nbd->xmit_timeout = 0;
+	nbd->tag_set.timeout = 0;
 	queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, nbd->disk->queue);
-	del_timer_sync(&nbd->timeout_timer);
 }
 
 static void nbd_bdev_reset(struct block_device *bdev)
@@ -700,33 +592,37 @@
 {
 	switch (cmd) {
 	case NBD_DISCONNECT: {
-		struct request sreq;
+		struct request *sreq;
 
 		dev_info(disk_to_dev(nbd->disk), "NBD_DISCONNECT\n");
 		if (!nbd->sock)
 			return -EINVAL;
 
+		sreq = blk_mq_alloc_request(bdev_get_queue(bdev), WRITE, 0);
+		if (!sreq)
+			return -ENOMEM;
+
 		mutex_unlock(&nbd->tx_lock);
 		fsync_bdev(bdev);
 		mutex_lock(&nbd->tx_lock);
-		blk_rq_init(NULL, &sreq);
-		sreq.cmd_type = REQ_TYPE_DRV_PRIV;
+		sreq->cmd_type = REQ_TYPE_DRV_PRIV;
 
 		/* Check again after getting mutex back.  */
-		if (!nbd->sock)
+		if (!nbd->sock) {
+			blk_mq_free_request(sreq);
 			return -EINVAL;
+		}
 
-		nbd->disconnect = true;
+		set_bit(NBD_DISCONNECT_REQUESTED, &nbd->runtime_flags);
 
-		nbd_send_req(nbd, &sreq);
+		nbd_send_cmd(nbd, blk_mq_rq_to_pdu(sreq));
+		blk_mq_free_request(sreq);
 		return 0;
 	}
  
 	case NBD_CLEAR_SOCK:
 		sock_shutdown(nbd);
 		nbd_clear_que(nbd);
-		BUG_ON(!list_empty(&nbd->queue_head));
-		BUG_ON(!list_empty(&nbd->waiting_queue));
 		kill_bdev(bdev);
 		return 0;
 
@@ -758,13 +654,7 @@
 		return nbd_size_set(nbd, bdev, nbd->blksize, arg);
 
 	case NBD_SET_TIMEOUT:
-		nbd->xmit_timeout = arg * HZ;
-		if (arg)
-			mod_timer(&nbd->timeout_timer,
-				  jiffies + nbd->xmit_timeout);
-		else
-			del_timer_sync(&nbd->timeout_timer);
-
+		nbd->tag_set.timeout = arg * HZ;
 		return 0;
 
 	case NBD_SET_FLAGS:
@@ -772,7 +662,6 @@
 		return 0;
 
 	case NBD_DO_IT: {
-		struct task_struct *thread;
 		int error;
 
 		if (nbd->task_recv)
@@ -786,18 +675,9 @@
 
 		nbd_parse_flags(nbd, bdev);
 
-		thread = kthread_run(nbd_thread_send, nbd, "%s",
-				     nbd_name(nbd));
-		if (IS_ERR(thread)) {
-			mutex_lock(&nbd->tx_lock);
-			nbd->task_recv = NULL;
-			return PTR_ERR(thread);
-		}
-
 		nbd_dev_dbg_init(nbd);
 		error = nbd_thread_recv(nbd, bdev);
 		nbd_dev_dbg_close(nbd);
-		kthread_stop(thread);
 
 		mutex_lock(&nbd->tx_lock);
 		nbd->task_recv = NULL;
@@ -807,9 +687,10 @@
 		kill_bdev(bdev);
 		nbd_bdev_reset(bdev);
 
-		if (nbd->disconnect) /* user requested, ignore socket errors */
+		/* user requested, ignore socket errors */
+		if (test_bit(NBD_DISCONNECT_REQUESTED, &nbd->runtime_flags))
 			error = 0;
-		if (nbd->timedout)
+		if (test_bit(NBD_TIMEDOUT, &nbd->runtime_flags))
 			error = -ETIMEDOUT;
 
 		nbd_reset(nbd);
@@ -825,10 +706,10 @@
 		return 0;
 
 	case NBD_PRINT_DEBUG:
-		dev_info(disk_to_dev(nbd->disk),
-			"next = %p, prev = %p, head = %p\n",
-			nbd->queue_head.next, nbd->queue_head.prev,
-			&nbd->queue_head);
+		/*
+		 * For compatibility only, we no longer keep a list of
+		 * outstanding requests.
+		 */
 		return 0;
 	}
 	return -ENOTTY;
@@ -935,7 +816,7 @@
 
 	debugfs_create_file("tasks", 0444, dir, nbd, &nbd_dbg_tasks_ops);
 	debugfs_create_u64("size_bytes", 0444, dir, &nbd->bytesize);
-	debugfs_create_u32("timeout", 0444, dir, &nbd->xmit_timeout);
+	debugfs_create_u32("timeout", 0444, dir, &nbd->tag_set.timeout);
 	debugfs_create_u32("blocksize", 0444, dir, &nbd->blksize);
 	debugfs_create_file("flags", 0444, dir, nbd, &nbd_dbg_flags_ops);
 
@@ -987,6 +868,24 @@
 
 #endif
 
+static int nbd_init_request(void *data, struct request *rq,
+			    unsigned int hctx_idx, unsigned int request_idx,
+			    unsigned int numa_node)
+{
+	struct nbd_cmd *cmd = blk_mq_rq_to_pdu(rq);
+
+	cmd->nbd = data;
+	INIT_LIST_HEAD(&cmd->list);
+	return 0;
+}
+
+static struct blk_mq_ops nbd_mq_ops = {
+	.queue_rq	= nbd_queue_rq,
+	.map_queue	= blk_mq_map_queue,
+	.init_request	= nbd_init_request,
+	.timeout	= nbd_xmit_timeout,
+};
+
 /*
  * And here should be modules and kernel interface 
  *  (Just smiley confuses emacs :-)
@@ -1035,16 +934,34 @@
 		if (!disk)
 			goto out;
 		nbd_dev[i].disk = disk;
+
+		nbd_dev[i].tag_set.ops = &nbd_mq_ops;
+		nbd_dev[i].tag_set.nr_hw_queues = 1;
+		nbd_dev[i].tag_set.queue_depth = 128;
+		nbd_dev[i].tag_set.numa_node = NUMA_NO_NODE;
+		nbd_dev[i].tag_set.cmd_size = sizeof(struct nbd_cmd);
+		nbd_dev[i].tag_set.flags = BLK_MQ_F_SHOULD_MERGE |
+			BLK_MQ_F_SG_MERGE | BLK_MQ_F_BLOCKING;
+		nbd_dev[i].tag_set.driver_data = &nbd_dev[i];
+
+		err = blk_mq_alloc_tag_set(&nbd_dev[i].tag_set);
+		if (err) {
+			put_disk(disk);
+			goto out;
+		}
+
 		/*
 		 * The new linux 2.5 block layer implementation requires
 		 * every gendisk to have its very own request_queue struct.
 		 * These structs are big so we dynamically allocate them.
 		 */
-		disk->queue = blk_init_queue(nbd_request_handler, &nbd_lock);
+		disk->queue = blk_mq_init_queue(&nbd_dev[i].tag_set);
 		if (!disk->queue) {
+			blk_mq_free_tag_set(&nbd_dev[i].tag_set);
 			put_disk(disk);
 			goto out;
 		}
+
 		/*
 		 * Tell the block layer that we are not a rotational device
 		 */
@@ -1069,16 +986,8 @@
 	for (i = 0; i < nbds_max; i++) {
 		struct gendisk *disk = nbd_dev[i].disk;
 		nbd_dev[i].magic = NBD_MAGIC;
-		INIT_LIST_HEAD(&nbd_dev[i].waiting_queue);
-		spin_lock_init(&nbd_dev[i].queue_lock);
 		spin_lock_init(&nbd_dev[i].sock_lock);
-		INIT_LIST_HEAD(&nbd_dev[i].queue_head);
 		mutex_init(&nbd_dev[i].tx_lock);
-		init_timer(&nbd_dev[i].timeout_timer);
-		nbd_dev[i].timeout_timer.function = nbd_xmit_timeout;
-		nbd_dev[i].timeout_timer.data = (unsigned long)&nbd_dev[i];
-		init_waitqueue_head(&nbd_dev[i].active_wq);
-		init_waitqueue_head(&nbd_dev[i].waiting_wq);
 		disk->major = NBD_MAJOR;
 		disk->first_minor = i << part_shift;
 		disk->fops = &nbd_fops;
@@ -1091,6 +1000,7 @@
 	return 0;
 out:
 	while (i--) {
+		blk_mq_free_tag_set(&nbd_dev[i].tag_set);
 		blk_cleanup_queue(nbd_dev[i].disk->queue);
 		put_disk(nbd_dev[i].disk);
 	}
@@ -1110,6 +1020,7 @@
 		if (disk) {
 			del_gendisk(disk);
 			blk_cleanup_queue(disk->queue);
+			blk_mq_free_tag_set(&nbd_dev[i].tag_set);
 			put_disk(disk);
 		}
 	}
diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c
index 75a7f88..91e1de8 100644
--- a/drivers/block/null_blk.c
+++ b/drivers/block/null_blk.c
@@ -34,6 +34,7 @@
 	unsigned int index;
 	struct request_queue *q;
 	struct gendisk *disk;
+	struct nvm_dev *ndev;
 	struct blk_mq_tag_set tag_set;
 	struct hrtimer timer;
 	unsigned int queue_depth;
@@ -414,23 +415,6 @@
 	kfree(nullb->queues);
 }
 
-static void null_del_dev(struct nullb *nullb)
-{
-	list_del_init(&nullb->list);
-
-	if (use_lightnvm)
-		nvm_unregister(nullb->disk_name);
-	else
-		del_gendisk(nullb->disk);
-	blk_cleanup_queue(nullb->q);
-	if (queue_mode == NULL_Q_MQ)
-		blk_mq_free_tag_set(&nullb->tag_set);
-	if (!use_lightnvm)
-		put_disk(nullb->disk);
-	cleanup_queues(nullb);
-	kfree(nullb);
-}
-
 #ifdef CONFIG_NVM
 
 static void null_lnvm_end_io(struct request *rq, int error)
@@ -564,10 +548,58 @@
 	/* Simulate nvme protocol restriction */
 	.max_phys_sect		= 64,
 };
+
+static int null_nvm_register(struct nullb *nullb)
+{
+	struct nvm_dev *dev;
+	int rv;
+
+	dev = nvm_alloc_dev(0);
+	if (!dev)
+		return -ENOMEM;
+
+	dev->q = nullb->q;
+	memcpy(dev->name, nullb->disk_name, DISK_NAME_LEN);
+	dev->ops = &null_lnvm_dev_ops;
+
+	rv = nvm_register(dev);
+	if (rv) {
+		kfree(dev);
+		return rv;
+	}
+	nullb->ndev = dev;
+	return 0;
+}
+
+static void null_nvm_unregister(struct nullb *nullb)
+{
+	nvm_unregister(nullb->ndev);
+}
 #else
-static struct nvm_dev_ops null_lnvm_dev_ops;
+static int null_nvm_register(struct nullb *nullb)
+{
+	return -EINVAL;
+}
+static void null_nvm_unregister(struct nullb *nullb) {}
 #endif /* CONFIG_NVM */
 
+static void null_del_dev(struct nullb *nullb)
+{
+	list_del_init(&nullb->list);
+
+	if (use_lightnvm)
+		null_nvm_unregister(nullb);
+	else
+		del_gendisk(nullb->disk);
+	blk_cleanup_queue(nullb->q);
+	if (queue_mode == NULL_Q_MQ)
+		blk_mq_free_tag_set(&nullb->tag_set);
+	if (!use_lightnvm)
+		put_disk(nullb->disk);
+	cleanup_queues(nullb);
+	kfree(nullb);
+}
+
 static int null_open(struct block_device *bdev, fmode_t mode)
 {
 	return 0;
@@ -640,11 +672,32 @@
 	return 0;
 }
 
-static int null_add_dev(void)
+static int null_gendisk_register(struct nullb *nullb)
 {
 	struct gendisk *disk;
-	struct nullb *nullb;
 	sector_t size;
+
+	disk = nullb->disk = alloc_disk_node(1, home_node);
+	if (!disk)
+		return -ENOMEM;
+	size = gb * 1024 * 1024 * 1024ULL;
+	set_capacity(disk, size >> 9);
+
+	disk->flags |= GENHD_FL_EXT_DEVT | GENHD_FL_SUPPRESS_PARTITION_INFO;
+	disk->major		= null_major;
+	disk->first_minor	= nullb->index;
+	disk->fops		= &null_fops;
+	disk->private_data	= nullb;
+	disk->queue		= nullb->q;
+	strncpy(disk->disk_name, nullb->disk_name, DISK_NAME_LEN);
+
+	add_disk(disk);
+	return 0;
+}
+
+static int null_add_dev(void)
+{
+	struct nullb *nullb;
 	int rv;
 
 	nullb = kzalloc_node(sizeof(*nullb), GFP_KERNEL, home_node);
@@ -716,42 +769,19 @@
 
 	sprintf(nullb->disk_name, "nullb%d", nullb->index);
 
-	if (use_lightnvm) {
-		rv = nvm_register(nullb->q, nullb->disk_name,
-							&null_lnvm_dev_ops);
-		if (rv)
-			goto out_cleanup_blk_queue;
-		goto done;
-	}
+	if (use_lightnvm)
+		rv = null_nvm_register(nullb);
+	else
+		rv = null_gendisk_register(nullb);
 
-	disk = nullb->disk = alloc_disk_node(1, home_node);
-	if (!disk) {
-		rv = -ENOMEM;
-		goto out_cleanup_lightnvm;
-	}
-	size = gb * 1024 * 1024 * 1024ULL;
-	set_capacity(disk, size >> 9);
+	if (rv)
+		goto out_cleanup_blk_queue;
 
-	disk->flags |= GENHD_FL_EXT_DEVT | GENHD_FL_SUPPRESS_PARTITION_INFO;
-	disk->major		= null_major;
-	disk->first_minor	= nullb->index;
-	disk->fops		= &null_fops;
-	disk->private_data	= nullb;
-	disk->queue		= nullb->q;
-	strncpy(disk->disk_name, nullb->disk_name, DISK_NAME_LEN);
-
-	add_disk(disk);
-
-done:
 	mutex_lock(&lock);
 	list_add_tail(&nullb->list, &nullb_list);
 	mutex_unlock(&lock);
 
 	return 0;
-
-out_cleanup_lightnvm:
-	if (use_lightnvm)
-		nvm_unregister(nullb->disk_name);
 out_cleanup_blk_queue:
 	blk_cleanup_queue(nullb->q);
 out_cleanup_tags:
diff --git a/drivers/lightnvm/Kconfig b/drivers/lightnvm/Kconfig
index 61c68a1..2f5d5f4 100644
--- a/drivers/lightnvm/Kconfig
+++ b/drivers/lightnvm/Kconfig
@@ -4,7 +4,7 @@
 
 menuconfig NVM
 	bool "Open-Channel SSD target support"
-	depends on BLOCK
+	depends on BLOCK && HAS_DMA
 	help
 	  Say Y here to get to enable Open-channel SSDs.
 
diff --git a/drivers/lightnvm/Makefile b/drivers/lightnvm/Makefile
index a7a0a22..1f6b652 100644
--- a/drivers/lightnvm/Makefile
+++ b/drivers/lightnvm/Makefile
@@ -2,6 +2,6 @@
 # Makefile for Open-Channel SSDs.
 #
 
-obj-$(CONFIG_NVM)		:= core.o sysblk.o
+obj-$(CONFIG_NVM)		:= core.o sysblk.o sysfs.o
 obj-$(CONFIG_NVM_GENNVM) 	+= gennvm.o
 obj-$(CONFIG_NVM_RRPC)		+= rrpc.o
diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
index c784ddc..1cac0f8 100644
--- a/drivers/lightnvm/core.c
+++ b/drivers/lightnvm/core.c
@@ -27,6 +27,8 @@
 #include <linux/lightnvm.h>
 #include <linux/sched/sysctl.h>
 
+#include "lightnvm.h"
+
 static LIST_HEAD(nvm_tgt_types);
 static DECLARE_RWSEM(nvm_tgtt_lock);
 static LIST_HEAD(nvm_mgrs);
@@ -581,6 +583,8 @@
 	mutex_init(&dev->mlock);
 	spin_lock_init(&dev->lock);
 
+	blk_queue_logical_block_size(dev->q, dev->sec_size);
+
 	return 0;
 err_fmtype:
 	kfree(dev->lun_map);
@@ -596,15 +600,19 @@
 	dev->mt = NULL;
 }
 
-static void nvm_free(struct nvm_dev *dev)
+void nvm_free(struct nvm_dev *dev)
 {
 	if (!dev)
 		return;
 
 	nvm_free_mgr(dev);
 
+	if (dev->dma_pool)
+		dev->ops->destroy_dma_pool(dev->dma_pool);
+
 	kfree(dev->lptbl);
 	kfree(dev->lun_map);
+	kfree(dev);
 }
 
 static int nvm_init(struct nvm_dev *dev)
@@ -651,30 +659,19 @@
 
 static void nvm_exit(struct nvm_dev *dev)
 {
-	if (dev->dma_pool)
-		dev->ops->destroy_dma_pool(dev->dma_pool);
-	nvm_free(dev);
-
-	pr_info("nvm: successfully unloaded\n");
+	nvm_sysfs_unregister_dev(dev);
 }
 
-int nvm_register(struct request_queue *q, char *disk_name,
-							struct nvm_dev_ops *ops)
+struct nvm_dev *nvm_alloc_dev(int node)
 {
-	struct nvm_dev *dev;
+	return kzalloc_node(sizeof(struct nvm_dev), GFP_KERNEL, node);
+}
+EXPORT_SYMBOL(nvm_alloc_dev);
+
+int nvm_register(struct nvm_dev *dev)
+{
 	int ret;
 
-	if (!ops->identity)
-		return -EINVAL;
-
-	dev = kzalloc(sizeof(struct nvm_dev), GFP_KERNEL);
-	if (!dev)
-		return -ENOMEM;
-
-	dev->q = q;
-	dev->ops = ops;
-	strncpy(dev->name, disk_name, DISK_NAME_LEN);
-
 	ret = nvm_init(dev);
 	if (ret)
 		goto err_init;
@@ -694,6 +691,10 @@
 		}
 	}
 
+	ret = nvm_sysfs_register_dev(dev);
+	if (ret)
+		goto err_ppalist;
+
 	if (dev->identity.cap & NVM_ID_DCAP_BBLKMGMT) {
 		ret = nvm_get_sysblock(dev, &dev->sb);
 		if (!ret)
@@ -710,31 +711,21 @@
 	up_write(&nvm_lock);
 
 	return 0;
+err_ppalist:
+	dev->ops->destroy_dma_pool(dev->dma_pool);
 err_init:
 	kfree(dev->lun_map);
-	kfree(dev);
 	return ret;
 }
 EXPORT_SYMBOL(nvm_register);
 
-void nvm_unregister(char *disk_name)
+void nvm_unregister(struct nvm_dev *dev)
 {
-	struct nvm_dev *dev;
-
 	down_write(&nvm_lock);
-	dev = nvm_find_nvm_dev(disk_name);
-	if (!dev) {
-		pr_err("nvm: could not find device %s to unregister\n",
-								disk_name);
-		up_write(&nvm_lock);
-		return;
-	}
-
 	list_del(&dev->devices);
 	up_write(&nvm_lock);
 
 	nvm_exit(dev);
-	kfree(dev);
 }
 EXPORT_SYMBOL(nvm_unregister);
 
diff --git a/drivers/lightnvm/lightnvm.h b/drivers/lightnvm/lightnvm.h
new file mode 100644
index 0000000..305c181
--- /dev/null
+++ b/drivers/lightnvm/lightnvm.h
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2016 CNEX Labs. All rights reserved.
+ * Initial release: Matias Bjorling <matias@cnexlabs.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
+ * USA.
+ *
+ */
+
+#ifndef LIGHTNVM_H
+#define LIGHTNVM_H
+
+#include <linux/lightnvm.h>
+
+/* core -> sysfs.c */
+int __must_check nvm_sysfs_register_dev(struct nvm_dev *);
+void nvm_sysfs_unregister_dev(struct nvm_dev *);
+int nvm_sysfs_register(void);
+void nvm_sysfs_unregister(void);
+
+/* sysfs > core */
+void nvm_free(struct nvm_dev *);
+
+#endif
diff --git a/drivers/lightnvm/sysfs.c b/drivers/lightnvm/sysfs.c
new file mode 100644
index 0000000..0338c27
--- /dev/null
+++ b/drivers/lightnvm/sysfs.c
@@ -0,0 +1,198 @@
+#include <linux/kernel.h>
+#include <linux/lightnvm.h>
+#include <linux/miscdevice.h>
+#include <linux/kobject.h>
+#include <linux/blk-mq.h>
+
+#include "lightnvm.h"
+
+static ssize_t nvm_dev_attr_show(struct device *dev,
+				 struct device_attribute *dattr, char *page)
+{
+	struct nvm_dev *ndev = container_of(dev, struct nvm_dev, dev);
+	struct nvm_id *id = &ndev->identity;
+	struct nvm_id_group *grp = &id->groups[0];
+	struct attribute *attr = &dattr->attr;
+
+	if (strcmp(attr->name, "version") == 0) {
+		return scnprintf(page, PAGE_SIZE, "%u\n", id->ver_id);
+	} else if (strcmp(attr->name, "vendor_opcode") == 0) {
+		return scnprintf(page, PAGE_SIZE, "%u\n", id->vmnt);
+	} else if (strcmp(attr->name, "capabilities") == 0) {
+		return scnprintf(page, PAGE_SIZE, "%u\n", id->cap);
+	} else if (strcmp(attr->name, "device_mode") == 0) {
+		return scnprintf(page, PAGE_SIZE, "%u\n", id->dom);
+	} else if (strcmp(attr->name, "media_manager") == 0) {
+		if (!ndev->mt)
+			return scnprintf(page, PAGE_SIZE, "%s\n", "none");
+		return scnprintf(page, PAGE_SIZE, "%s\n", ndev->mt->name);
+	} else if (strcmp(attr->name, "ppa_format") == 0) {
+		return scnprintf(page, PAGE_SIZE,
+			"0x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x\n",
+			id->ppaf.ch_offset, id->ppaf.ch_len,
+			id->ppaf.lun_offset, id->ppaf.lun_len,
+			id->ppaf.pln_offset, id->ppaf.pln_len,
+			id->ppaf.blk_offset, id->ppaf.blk_len,
+			id->ppaf.pg_offset, id->ppaf.pg_len,
+			id->ppaf.sect_offset, id->ppaf.sect_len);
+	} else if (strcmp(attr->name, "media_type") == 0) {	/* u8 */
+		return scnprintf(page, PAGE_SIZE, "%u\n", grp->mtype);
+	} else if (strcmp(attr->name, "flash_media_type") == 0) {
+		return scnprintf(page, PAGE_SIZE, "%u\n", grp->fmtype);
+	} else if (strcmp(attr->name, "num_channels") == 0) {
+		return scnprintf(page, PAGE_SIZE, "%u\n", grp->num_ch);
+	} else if (strcmp(attr->name, "num_luns") == 0) {
+		return scnprintf(page, PAGE_SIZE, "%u\n", grp->num_lun);
+	} else if (strcmp(attr->name, "num_planes") == 0) {
+		return scnprintf(page, PAGE_SIZE, "%u\n", grp->num_pln);
+	} else if (strcmp(attr->name, "num_blocks") == 0) {	/* u16 */
+		return scnprintf(page, PAGE_SIZE, "%u\n", grp->num_blk);
+	} else if (strcmp(attr->name, "num_pages") == 0) {
+		return scnprintf(page, PAGE_SIZE, "%u\n", grp->num_pg);
+	} else if (strcmp(attr->name, "page_size") == 0) {
+		return scnprintf(page, PAGE_SIZE, "%u\n", grp->fpg_sz);
+	} else if (strcmp(attr->name, "hw_sector_size") == 0) {
+		return scnprintf(page, PAGE_SIZE, "%u\n", grp->csecs);
+	} else if (strcmp(attr->name, "oob_sector_size") == 0) {/* u32 */
+		return scnprintf(page, PAGE_SIZE, "%u\n", grp->sos);
+	} else if (strcmp(attr->name, "read_typ") == 0) {
+		return scnprintf(page, PAGE_SIZE, "%u\n", grp->trdt);
+	} else if (strcmp(attr->name, "read_max") == 0) {
+		return scnprintf(page, PAGE_SIZE, "%u\n", grp->trdm);
+	} else if (strcmp(attr->name, "prog_typ") == 0) {
+		return scnprintf(page, PAGE_SIZE, "%u\n", grp->tprt);
+	} else if (strcmp(attr->name, "prog_max") == 0) {
+		return scnprintf(page, PAGE_SIZE, "%u\n", grp->tprm);
+	} else if (strcmp(attr->name, "erase_typ") == 0) {
+		return scnprintf(page, PAGE_SIZE, "%u\n", grp->tbet);
+	} else if (strcmp(attr->name, "erase_max") == 0) {
+		return scnprintf(page, PAGE_SIZE, "%u\n", grp->tbem);
+	} else if (strcmp(attr->name, "multiplane_modes") == 0) {
+		return scnprintf(page, PAGE_SIZE, "0x%08x\n", grp->mpos);
+	} else if (strcmp(attr->name, "media_capabilities") == 0) {
+		return scnprintf(page, PAGE_SIZE, "0x%08x\n", grp->mccap);
+	} else if (strcmp(attr->name, "max_phys_secs") == 0) {
+		return scnprintf(page, PAGE_SIZE, "%u\n",
+				ndev->ops->max_phys_sect);
+	} else {
+		return scnprintf(page,
+				 PAGE_SIZE,
+				 "Unhandled attr(%s) in `nvm_dev_attr_show`\n",
+				 attr->name);
+	}
+}
+
+#define NVM_DEV_ATTR_RO(_name)						\
+	DEVICE_ATTR(_name, S_IRUGO, nvm_dev_attr_show, NULL)
+
+static NVM_DEV_ATTR_RO(version);
+static NVM_DEV_ATTR_RO(vendor_opcode);
+static NVM_DEV_ATTR_RO(capabilities);
+static NVM_DEV_ATTR_RO(device_mode);
+static NVM_DEV_ATTR_RO(ppa_format);
+static NVM_DEV_ATTR_RO(media_manager);
+
+static NVM_DEV_ATTR_RO(media_type);
+static NVM_DEV_ATTR_RO(flash_media_type);
+static NVM_DEV_ATTR_RO(num_channels);
+static NVM_DEV_ATTR_RO(num_luns);
+static NVM_DEV_ATTR_RO(num_planes);
+static NVM_DEV_ATTR_RO(num_blocks);
+static NVM_DEV_ATTR_RO(num_pages);
+static NVM_DEV_ATTR_RO(page_size);
+static NVM_DEV_ATTR_RO(hw_sector_size);
+static NVM_DEV_ATTR_RO(oob_sector_size);
+static NVM_DEV_ATTR_RO(read_typ);
+static NVM_DEV_ATTR_RO(read_max);
+static NVM_DEV_ATTR_RO(prog_typ);
+static NVM_DEV_ATTR_RO(prog_max);
+static NVM_DEV_ATTR_RO(erase_typ);
+static NVM_DEV_ATTR_RO(erase_max);
+static NVM_DEV_ATTR_RO(multiplane_modes);
+static NVM_DEV_ATTR_RO(media_capabilities);
+static NVM_DEV_ATTR_RO(max_phys_secs);
+
+#define NVM_DEV_ATTR(_name) (dev_attr_##_name##)
+
+static struct attribute *nvm_dev_attrs[] = {
+	&dev_attr_version.attr,
+	&dev_attr_vendor_opcode.attr,
+	&dev_attr_capabilities.attr,
+	&dev_attr_device_mode.attr,
+	&dev_attr_media_manager.attr,
+
+	&dev_attr_ppa_format.attr,
+	&dev_attr_media_type.attr,
+	&dev_attr_flash_media_type.attr,
+	&dev_attr_num_channels.attr,
+	&dev_attr_num_luns.attr,
+	&dev_attr_num_planes.attr,
+	&dev_attr_num_blocks.attr,
+	&dev_attr_num_pages.attr,
+	&dev_attr_page_size.attr,
+	&dev_attr_hw_sector_size.attr,
+	&dev_attr_oob_sector_size.attr,
+	&dev_attr_read_typ.attr,
+	&dev_attr_read_max.attr,
+	&dev_attr_prog_typ.attr,
+	&dev_attr_prog_max.attr,
+	&dev_attr_erase_typ.attr,
+	&dev_attr_erase_max.attr,
+	&dev_attr_multiplane_modes.attr,
+	&dev_attr_media_capabilities.attr,
+	&dev_attr_max_phys_secs.attr,
+	NULL,
+};
+
+static struct attribute_group nvm_dev_attr_group = {
+	.name = "lightnvm",
+	.attrs = nvm_dev_attrs,
+};
+
+static const struct attribute_group *nvm_dev_attr_groups[] = {
+	&nvm_dev_attr_group,
+	NULL,
+};
+
+static void nvm_dev_release(struct device *device)
+{
+	struct nvm_dev *dev = container_of(device, struct nvm_dev, dev);
+	struct request_queue *q = dev->q;
+
+	pr_debug("nvm/sysfs: `nvm_dev_release`\n");
+
+	blk_mq_unregister_dev(device, q);
+
+	nvm_free(dev);
+}
+
+static struct device_type nvm_type = {
+	.name		= "lightnvm",
+	.groups		= nvm_dev_attr_groups,
+	.release	= nvm_dev_release,
+};
+
+int nvm_sysfs_register_dev(struct nvm_dev *dev)
+{
+	int ret;
+
+	if (!dev->parent_dev)
+		return 0;
+
+	dev->dev.parent = dev->parent_dev;
+	dev_set_name(&dev->dev, "%s", dev->name);
+	dev->dev.type = &nvm_type;
+	device_initialize(&dev->dev);
+	ret = device_add(&dev->dev);
+
+	if (!ret)
+		blk_mq_register_dev(&dev->dev, dev->q);
+
+	return ret;
+}
+
+void nvm_sysfs_unregister_dev(struct nvm_dev *dev)
+{
+	if (dev && dev->parent_dev)
+		kobject_put(&dev->dev.kobj);
+}
diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index 76f7534..81d3db4 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -361,12 +361,8 @@
 static void btree_node_write_done(struct closure *cl)
 {
 	struct btree *b = container_of(cl, struct btree, io);
-	struct bio_vec *bv;
-	int n;
 
-	bio_for_each_segment_all(bv, b->bio, n)
-		__free_page(bv->bv_page);
-
+	bio_free_pages(b->bio);
 	__btree_node_write_done(cl);
 }
 
diff --git a/drivers/md/bcache/debug.c b/drivers/md/bcache/debug.c
index c28df164..333a1e5 100644
--- a/drivers/md/bcache/debug.c
+++ b/drivers/md/bcache/debug.c
@@ -107,9 +107,8 @@
 {
 	char name[BDEVNAME_SIZE];
 	struct bio *check;
-	struct bio_vec bv, *bv2;
+	struct bio_vec bv;
 	struct bvec_iter iter;
-	int i;
 
 	check = bio_clone(bio, GFP_NOIO);
 	if (!check)
@@ -136,8 +135,7 @@
 		kunmap_atomic(p1);
 	}
 
-	bio_for_each_segment_all(bv2, check, i)
-		__free_page(bv2->bv_page);
+	bio_free_pages(check);
 out_put:
 	bio_put(check);
 }
diff --git a/drivers/md/bcache/movinggc.c b/drivers/md/bcache/movinggc.c
index 1881319..5c4bdde 100644
--- a/drivers/md/bcache/movinggc.c
+++ b/drivers/md/bcache/movinggc.c
@@ -44,11 +44,8 @@
 {
 	struct moving_io *io = container_of(cl, struct moving_io, cl);
 	struct bio *bio = &io->bio.bio;
-	struct bio_vec *bv;
-	int i;
 
-	bio_for_each_segment_all(bv, bio, i)
-		__free_page(bv->bv_page);
+	bio_free_pages(bio);
 
 	if (io->op.replace_collision)
 		trace_bcache_gc_copy_collision(&io->w->key);
diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c
index 4b177fe..40ffe5e 100644
--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -694,13 +694,8 @@
 	if (s->iop.replace_collision)
 		bch_mark_cache_miss_collision(s->iop.c, s->d);
 
-	if (s->iop.bio) {
-		int i;
-		struct bio_vec *bv;
-
-		bio_for_each_segment_all(bv, s->iop.bio, i)
-			__free_page(bv->bv_page);
-	}
+	if (s->iop.bio)
+		bio_free_pages(s->iop.bio);
 
 	cached_dev_bio_complete(cl);
 }
diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c
index d9fd2a6..e51644e 100644
--- a/drivers/md/bcache/writeback.c
+++ b/drivers/md/bcache/writeback.c
@@ -128,11 +128,8 @@
 	struct dirty_io *io = container_of(cl, struct dirty_io, cl);
 	struct keybuf_key *w = io->bio.bi_private;
 	struct cached_dev *dc = io->dc;
-	struct bio_vec *bv;
-	int i;
 
-	bio_for_each_segment_all(bv, &io->bio, i)
-		__free_page(bv->bv_page);
+	bio_free_pages(&io->bio);
 
 	/* This is kind of a dumb way of signalling errors. */
 	if (KEY_DIRTY(&w->key)) {
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 8742957..0448e7e 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1136,7 +1136,7 @@
 	clone->bi_private = io;
 	clone->bi_end_io  = crypt_endio;
 	clone->bi_bdev    = cc->dev->bdev;
-	bio_set_op_attrs(clone, bio_op(io->base_bio), io->base_bio->bi_opf);
+	bio_set_op_attrs(clone, bio_op(io->base_bio), bio_flags(io->base_bio));
 }
 
 static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
diff --git a/drivers/md/dm-log-writes.c b/drivers/md/dm-log-writes.c
index 49e4d8d..4dfe386 100644
--- a/drivers/md/dm-log-writes.c
+++ b/drivers/md/dm-log-writes.c
@@ -149,8 +149,6 @@
 static void log_end_io(struct bio *bio)
 {
 	struct log_writes_c *lc = bio->bi_private;
-	struct bio_vec *bvec;
-	int i;
 
 	if (bio->bi_error) {
 		unsigned long flags;
@@ -161,9 +159,7 @@
 		spin_unlock_irqrestore(&lc->blocks_lock, flags);
 	}
 
-	bio_for_each_segment_all(bvec, bio, i)
-		__free_page(bvec->bv_page);
-
+	bio_free_pages(bio);
 	put_io_block(lc);
 	bio_put(bio);
 }
diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c
index 1ca7463..ee48230 100644
--- a/drivers/md/dm-rq.c
+++ b/drivers/md/dm-rq.c
@@ -955,7 +955,7 @@
 	dm_init_md_queue(md);
 
 	/* backfill 'mq' sysfs registration normally done in blk_register_queue */
-	blk_mq_register_disk(md->disk);
+	blk_mq_register_dev(disk_to_dev(md->disk), q);
 
 	return 0;
 
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 21dc00e..1961d82 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -145,12 +145,8 @@
 	return r1_bio;
 
 out_free_pages:
-	while (--j >= 0) {
-		struct bio_vec *bv;
-
-		bio_for_each_segment_all(bv, r1_bio->bios[j], i)
-			__free_page(bv->bv_page);
-	}
+	while (--j >= 0)
+		bio_free_pages(r1_bio->bios[j]);
 
 out_free_bio:
 	while (++j < pi->raid_disks)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 2feacc7..4669c05 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -156,12 +156,14 @@
 {
 	struct nvme_ns *ns = container_of(kref, struct nvme_ns, kref);
 
-	if (ns->type == NVME_NS_LIGHTNVM)
-		nvme_nvm_unregister(ns->queue, ns->disk->disk_name);
+	if (ns->ndev)
+		nvme_nvm_unregister(ns);
 
-	spin_lock(&dev_list_lock);
-	ns->disk->private_data = NULL;
-	spin_unlock(&dev_list_lock);
+	if (ns->disk) {
+		spin_lock(&dev_list_lock);
+		ns->disk->private_data = NULL;
+		spin_unlock(&dev_list_lock);
+	}
 
 	put_disk(ns->disk);
 	ida_simple_remove(&ns->ctrl->ns_ida, ns->instance);
@@ -597,7 +599,7 @@
 }
 
 int nvme_get_features(struct nvme_ctrl *dev, unsigned fid, unsigned nsid,
-					dma_addr_t dma_addr, u32 *result)
+		      void *buffer, size_t buflen, u32 *result)
 {
 	struct nvme_command c;
 	struct nvme_completion cqe;
@@ -606,10 +608,9 @@
 	memset(&c, 0, sizeof(c));
 	c.features.opcode = nvme_admin_get_features;
 	c.features.nsid = cpu_to_le32(nsid);
-	c.features.dptr.prp1 = cpu_to_le64(dma_addr);
 	c.features.fid = cpu_to_le32(fid);
 
-	ret = __nvme_submit_sync_cmd(dev->admin_q, &c, &cqe, NULL, 0, 0,
+	ret = __nvme_submit_sync_cmd(dev->admin_q, &c, &cqe, buffer, buflen, 0,
 			NVME_QID_ANY, 0, 0);
 	if (ret >= 0 && result)
 		*result = le32_to_cpu(cqe.result);
@@ -617,7 +618,7 @@
 }
 
 int nvme_set_features(struct nvme_ctrl *dev, unsigned fid, unsigned dword11,
-					dma_addr_t dma_addr, u32 *result)
+		      void *buffer, size_t buflen, u32 *result)
 {
 	struct nvme_command c;
 	struct nvme_completion cqe;
@@ -625,12 +626,11 @@
 
 	memset(&c, 0, sizeof(c));
 	c.features.opcode = nvme_admin_set_features;
-	c.features.dptr.prp1 = cpu_to_le64(dma_addr);
 	c.features.fid = cpu_to_le32(fid);
 	c.features.dword11 = cpu_to_le32(dword11);
 
-	ret = __nvme_submit_sync_cmd(dev->admin_q, &c, &cqe, NULL, 0, 0,
-			NVME_QID_ANY, 0, 0);
+	ret = __nvme_submit_sync_cmd(dev->admin_q, &c, &cqe,
+			buffer, buflen, 0, NVME_QID_ANY, 0, 0);
 	if (ret >= 0 && result)
 		*result = le32_to_cpu(cqe.result);
 	return ret;
@@ -664,7 +664,7 @@
 	u32 result;
 	int status, nr_io_queues;
 
-	status = nvme_set_features(ctrl, NVME_FEAT_NUM_QUEUES, q_count, 0,
+	status = nvme_set_features(ctrl, NVME_FEAT_NUM_QUEUES, q_count, NULL, 0,
 			&result);
 	if (status < 0)
 		return status;
@@ -888,42 +888,32 @@
 	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, ns->queue);
 }
 
-static int nvme_revalidate_disk(struct gendisk *disk)
+static int nvme_revalidate_ns(struct nvme_ns *ns, struct nvme_id_ns **id)
 {
-	struct nvme_ns *ns = disk->private_data;
-	struct nvme_id_ns *id;
-	u8 lbaf, pi_type;
-	u16 old_ms;
-	unsigned short bs;
-
-	if (test_bit(NVME_NS_DEAD, &ns->flags)) {
-		set_capacity(disk, 0);
-		return -ENODEV;
-	}
-	if (nvme_identify_ns(ns->ctrl, ns->ns_id, &id)) {
-		dev_warn(disk_to_dev(ns->disk), "%s: Identify failure\n",
-				__func__);
-		return -ENODEV;
-	}
-	if (id->ncap == 0) {
-		kfree(id);
+	if (nvme_identify_ns(ns->ctrl, ns->ns_id, id)) {
+		dev_warn(ns->ctrl->dev, "%s: Identify failure\n", __func__);
 		return -ENODEV;
 	}
 
-	if (nvme_nvm_ns_supported(ns, id) && ns->type != NVME_NS_LIGHTNVM) {
-		if (nvme_nvm_register(ns->queue, disk->disk_name)) {
-			dev_warn(disk_to_dev(ns->disk),
-				"%s: LightNVM init failure\n", __func__);
-			kfree(id);
-			return -ENODEV;
-		}
-		ns->type = NVME_NS_LIGHTNVM;
+	if ((*id)->ncap == 0) {
+		kfree(*id);
+		return -ENODEV;
 	}
 
 	if (ns->ctrl->vs >= NVME_VS(1, 1))
-		memcpy(ns->eui, id->eui64, sizeof(ns->eui));
+		memcpy(ns->eui, (*id)->eui64, sizeof(ns->eui));
 	if (ns->ctrl->vs >= NVME_VS(1, 2))
-		memcpy(ns->uuid, id->nguid, sizeof(ns->uuid));
+		memcpy(ns->uuid, (*id)->nguid, sizeof(ns->uuid));
+
+	return 0;
+}
+
+static void __nvme_revalidate_disk(struct gendisk *disk, struct nvme_id_ns *id)
+{
+	struct nvme_ns *ns = disk->private_data;
+	u8 lbaf, pi_type;
+	u16 old_ms;
+	unsigned short bs;
 
 	old_ms = ns->ms;
 	lbaf = id->flbas & NVME_NS_FLBAS_LBA_MASK;
@@ -962,8 +952,26 @@
 	if (ns->ctrl->oncs & NVME_CTRL_ONCS_DSM)
 		nvme_config_discard(ns);
 	blk_mq_unfreeze_queue(disk->queue);
+}
 
+static int nvme_revalidate_disk(struct gendisk *disk)
+{
+	struct nvme_ns *ns = disk->private_data;
+	struct nvme_id_ns *id = NULL;
+	int ret;
+
+	if (test_bit(NVME_NS_DEAD, &ns->flags)) {
+		set_capacity(disk, 0);
+		return -ENODEV;
+	}
+
+	ret = nvme_revalidate_ns(ns, &id);
+	if (ret)
+		return ret;
+
+	__nvme_revalidate_disk(disk, id);
 	kfree(id);
+
 	return 0;
 }
 
@@ -1425,7 +1433,7 @@
 static ssize_t wwid_show(struct device *dev, struct device_attribute *attr,
 								char *buf)
 {
-	struct nvme_ns *ns = dev_to_disk(dev)->private_data;
+	struct nvme_ns *ns = nvme_get_ns_from_dev(dev);
 	struct nvme_ctrl *ctrl = ns->ctrl;
 	int serial_len = sizeof(ctrl->serial);
 	int model_len = sizeof(ctrl->model);
@@ -1449,7 +1457,7 @@
 static ssize_t uuid_show(struct device *dev, struct device_attribute *attr,
 								char *buf)
 {
-	struct nvme_ns *ns = dev_to_disk(dev)->private_data;
+	struct nvme_ns *ns = nvme_get_ns_from_dev(dev);
 	return sprintf(buf, "%pU\n", ns->uuid);
 }
 static DEVICE_ATTR(uuid, S_IRUGO, uuid_show, NULL);
@@ -1457,7 +1465,7 @@
 static ssize_t eui_show(struct device *dev, struct device_attribute *attr,
 								char *buf)
 {
-	struct nvme_ns *ns = dev_to_disk(dev)->private_data;
+	struct nvme_ns *ns = nvme_get_ns_from_dev(dev);
 	return sprintf(buf, "%8phd\n", ns->eui);
 }
 static DEVICE_ATTR(eui, S_IRUGO, eui_show, NULL);
@@ -1465,7 +1473,7 @@
 static ssize_t nsid_show(struct device *dev, struct device_attribute *attr,
 								char *buf)
 {
-	struct nvme_ns *ns = dev_to_disk(dev)->private_data;
+	struct nvme_ns *ns = nvme_get_ns_from_dev(dev);
 	return sprintf(buf, "%d\n", ns->ns_id);
 }
 static DEVICE_ATTR(nsid, S_IRUGO, nsid_show, NULL);
@@ -1482,7 +1490,7 @@
 		struct attribute *a, int n)
 {
 	struct device *dev = container_of(kobj, struct device, kobj);
-	struct nvme_ns *ns = dev_to_disk(dev)->private_data;
+	struct nvme_ns *ns = nvme_get_ns_from_dev(dev);
 
 	if (a == &dev_attr_uuid.attr) {
 		if (!memchr_inv(ns->uuid, 0, sizeof(ns->uuid)))
@@ -1642,6 +1650,8 @@
 {
 	struct nvme_ns *ns;
 	struct gendisk *disk;
+	struct nvme_id_ns *id;
+	char disk_name[DISK_NAME_LEN];
 	int node = dev_to_node(ctrl->dev);
 
 	ns = kzalloc_node(sizeof(*ns), GFP_KERNEL, node);
@@ -1659,34 +1669,49 @@
 	ns->queue->queuedata = ns;
 	ns->ctrl = ctrl;
 
-	disk = alloc_disk_node(0, node);
-	if (!disk)
-		goto out_free_queue;
-
 	kref_init(&ns->kref);
 	ns->ns_id = nsid;
-	ns->disk = disk;
 	ns->lba_shift = 9; /* set to a default value for 512 until disk is validated */
 
-
 	blk_queue_logical_block_size(ns->queue, 1 << ns->lba_shift);
 	nvme_set_queue_limits(ctrl, ns->queue);
 
-	disk->fops = &nvme_fops;
-	disk->private_data = ns;
-	disk->queue = ns->queue;
-	disk->flags = GENHD_FL_EXT_DEVT;
-	sprintf(disk->disk_name, "nvme%dn%d", ctrl->instance, ns->instance);
+	sprintf(disk_name, "nvme%dn%d", ctrl->instance, ns->instance);
 
-	if (nvme_revalidate_disk(ns->disk))
-		goto out_free_disk;
+	if (nvme_revalidate_ns(ns, &id))
+		goto out_free_queue;
+
+	if (nvme_nvm_ns_supported(ns, id)) {
+		if (nvme_nvm_register(ns, disk_name, node,
+							&nvme_ns_attr_group)) {
+			dev_warn(ctrl->dev, "%s: LightNVM init failure\n",
+								__func__);
+			goto out_free_id;
+		}
+	} else {
+		disk = alloc_disk_node(0, node);
+		if (!disk)
+			goto out_free_id;
+
+		disk->fops = &nvme_fops;
+		disk->private_data = ns;
+		disk->queue = ns->queue;
+		disk->flags = GENHD_FL_EXT_DEVT;
+		memcpy(disk->disk_name, disk_name, DISK_NAME_LEN);
+		ns->disk = disk;
+
+		__nvme_revalidate_disk(disk, id);
+	}
 
 	mutex_lock(&ctrl->namespaces_mutex);
 	list_add_tail(&ns->list, &ctrl->namespaces);
 	mutex_unlock(&ctrl->namespaces_mutex);
 
 	kref_get(&ctrl->kref);
-	if (ns->type == NVME_NS_LIGHTNVM)
+
+	kfree(id);
+
+	if (ns->ndev)
 		return;
 
 	device_add_disk(ctrl->device, ns->disk);
@@ -1695,8 +1720,8 @@
 		pr_warn("%s: failed to create sysfs group for identification\n",
 			ns->disk->disk_name);
 	return;
- out_free_disk:
-	kfree(disk);
+ out_free_id:
+	kfree(id);
  out_free_queue:
 	blk_cleanup_queue(ns->queue);
  out_release_instance:
@@ -1710,7 +1735,7 @@
 	if (test_and_set_bit(NVME_NS_REMOVING, &ns->flags))
 		return;
 
-	if (ns->disk->flags & GENHD_FL_UP) {
+	if (ns->disk && ns->disk->flags & GENHD_FL_UP) {
 		if (blk_get_integrity(ns->disk))
 			blk_integrity_unregister(ns->disk);
 		sysfs_remove_group(&disk_to_dev(ns->disk)->kobj,
@@ -1733,7 +1758,7 @@
 
 	ns = nvme_find_get_ns(ctrl, nsid);
 	if (ns) {
-		if (revalidate_disk(ns->disk))
+		if (ns->disk && revalidate_disk(ns->disk))
 			nvme_ns_remove(ns);
 		nvme_put_ns(ns);
 	} else
@@ -2038,7 +2063,7 @@
 		 * Revalidating a dead namespace sets capacity to 0. This will
 		 * end buffered writers dirtying pages that can't be synced.
 		 */
-		if (!test_and_set_bit(NVME_NS_DEAD, &ns->flags))
+		if (ns->disk && !test_and_set_bit(NVME_NS_DEAD, &ns->flags))
 			revalidate_disk(ns->disk);
 
 		blk_set_queue_dying(ns->queue);
diff --git a/drivers/nvme/host/fabrics.c b/drivers/nvme/host/fabrics.c
index 4eff491..5a3f008 100644
--- a/drivers/nvme/host/fabrics.c
+++ b/drivers/nvme/host/fabrics.c
@@ -111,8 +111,19 @@
  */
 int nvmf_get_address(struct nvme_ctrl *ctrl, char *buf, int size)
 {
-	return snprintf(buf, size, "traddr=%s,trsvcid=%s\n",
-			ctrl->opts->traddr, ctrl->opts->trsvcid);
+	int len = 0;
+
+	if (ctrl->opts->mask & NVMF_OPT_TRADDR)
+		len += snprintf(buf, size, "traddr=%s", ctrl->opts->traddr);
+	if (ctrl->opts->mask & NVMF_OPT_TRSVCID)
+		len += snprintf(buf + len, size - len, "%strsvcid=%s",
+				(len) ? "," : "", ctrl->opts->trsvcid);
+	if (ctrl->opts->mask & NVMF_OPT_HOST_TRADDR)
+		len += snprintf(buf + len, size - len, "%shost_traddr=%s",
+				(len) ? "," : "", ctrl->opts->host_traddr);
+	len += snprintf(buf + len, size - len, "\n");
+
+	return len;
 }
 EXPORT_SYMBOL_GPL(nvmf_get_address);
 
@@ -519,6 +530,7 @@
 	{ NVMF_OPT_RECONNECT_DELAY,	"reconnect_delay=%d"	},
 	{ NVMF_OPT_KATO,		"keep_alive_tmo=%d"	},
 	{ NVMF_OPT_HOSTNQN,		"hostnqn=%s"		},
+	{ NVMF_OPT_HOST_TRADDR,		"host_traddr=%s"	},
 	{ NVMF_OPT_ERR,			NULL			}
 };
 
@@ -675,6 +687,14 @@
 			}
 			opts->reconnect_delay = token;
 			break;
+		case NVMF_OPT_HOST_TRADDR:
+			p = match_strdup(args);
+			if (!p) {
+				ret = -ENOMEM;
+				goto out;
+			}
+			opts->host_traddr = p;
+			break;
 		default:
 			pr_warn("unknown parameter or missing value '%s' in ctrl creation request\n",
 				p);
@@ -741,6 +761,7 @@
 	kfree(opts->traddr);
 	kfree(opts->trsvcid);
 	kfree(opts->subsysnqn);
+	kfree(opts->host_traddr);
 	kfree(opts);
 }
 EXPORT_SYMBOL_GPL(nvmf_free_options);
diff --git a/drivers/nvme/host/fabrics.h b/drivers/nvme/host/fabrics.h
index 46e460a..924145c9 100644
--- a/drivers/nvme/host/fabrics.h
+++ b/drivers/nvme/host/fabrics.h
@@ -52,6 +52,7 @@
 	NVMF_OPT_KATO		= 1 << 7,
 	NVMF_OPT_HOSTNQN	= 1 << 8,
 	NVMF_OPT_RECONNECT_DELAY = 1 << 9,
+	NVMF_OPT_HOST_TRADDR	= 1 << 10,
 };
 
 /**
@@ -64,9 +65,12 @@
  *		being added.
  * @subsysnqn:	Hold the fully qualified NQN subystem name (format defined
  *		in the NVMe specification, "NVMe Qualified Names").
- * @traddr:	network address that will be used by the host to communicate
- *		to the added NVMe controller.
- * @trsvcid:	network port used for host-controller communication.
+ * @traddr:	The transport-specific TRADDR field for a port on the
+ *              subsystem which is adding a controller.
+ * @trsvcid:	The transport-specific TRSVCID field for a port on the
+ *              subsystem which is adding a controller.
+ * @host_traddr: A transport-specific field identifying the NVME host port
+ *              to use for the connection to the controller.
  * @queue_size: Number of IO queue elements.
  * @nr_io_queues: Number of controller IO queues that will be established.
  * @reconnect_delay: Time between two consecutive reconnect attempts.
@@ -80,6 +84,7 @@
 	char			*subsysnqn;
 	char			*traddr;
 	char			*trsvcid;
+	char			*host_traddr;
 	size_t			queue_size;
 	unsigned int		nr_io_queues;
 	unsigned int		reconnect_delay;
diff --git a/drivers/nvme/host/lightnvm.c b/drivers/nvme/host/lightnvm.c
index 63f483d..f5e3011 100644
--- a/drivers/nvme/host/lightnvm.c
+++ b/drivers/nvme/host/lightnvm.c
@@ -475,7 +475,7 @@
 
 	if (rqd->opcode == NVM_OP_HBWRITE || rqd->opcode == NVM_OP_HBREAD)
 		c->hb_rw.slba = cpu_to_le64(nvme_block_nr(ns,
-						rqd->bio->bi_iter.bi_sector));
+					rqd->bio->bi_iter.bi_sector));
 }
 
 static void nvme_nvm_end_io(struct request *rq, int error)
@@ -592,14 +592,37 @@
 	.max_phys_sect		= 64,
 };
 
-int nvme_nvm_register(struct request_queue *q, char *disk_name)
+int nvme_nvm_register(struct nvme_ns *ns, char *disk_name, int node,
+		      const struct attribute_group *attrs)
 {
-	return nvm_register(q, disk_name, &nvme_nvm_dev_ops);
+	struct request_queue *q = ns->queue;
+	struct nvm_dev *dev;
+	int ret;
+
+	dev = nvm_alloc_dev(node);
+	if (!dev)
+		return -ENOMEM;
+
+	dev->q = q;
+	memcpy(dev->name, disk_name, DISK_NAME_LEN);
+	dev->ops = &nvme_nvm_dev_ops;
+	dev->parent_dev = ns->ctrl->device;
+	dev->private_data = ns;
+	ns->ndev = dev;
+
+	ret = nvm_register(dev);
+
+	ns->lba_shift = ilog2(dev->sec_size) - 9;
+
+	if (sysfs_create_group(&dev->dev.kobj, attrs))
+		pr_warn("%s: failed to create sysfs group for identification\n",
+			disk_name);
+	return ret;
 }
 
-void nvme_nvm_unregister(struct request_queue *q, char *disk_name)
+void nvme_nvm_unregister(struct nvme_ns *ns)
 {
-	nvm_unregister(disk_name);
+	nvm_unregister(ns->ndev);
 }
 
 /* move to shared place when used in multiple places. */
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index ab18b78..b0a9ec6 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -18,6 +18,7 @@
 #include <linux/pci.h>
 #include <linux/kref.h>
 #include <linux/blk-mq.h>
+#include <linux/lightnvm.h>
 
 enum {
 	/*
@@ -154,6 +155,7 @@
 	struct nvme_ctrl *ctrl;
 	struct request_queue *queue;
 	struct gendisk *disk;
+	struct nvm_dev *ndev;
 	struct kref kref;
 	int instance;
 
@@ -165,7 +167,6 @@
 	u16 ms;
 	bool ext;
 	u8 pi_type;
-	int type;
 	unsigned long flags;
 
 #define NVME_NS_REMOVING 0
@@ -292,9 +293,9 @@
 		struct nvme_id_ns **id);
 int nvme_get_log_page(struct nvme_ctrl *dev, struct nvme_smart_log **log);
 int nvme_get_features(struct nvme_ctrl *dev, unsigned fid, unsigned nsid,
-			dma_addr_t dma_addr, u32 *result);
+		      void *buffer, size_t buflen, u32 *result);
 int nvme_set_features(struct nvme_ctrl *dev, unsigned fid, unsigned dword11,
-			dma_addr_t dma_addr, u32 *result);
+		      void *buffer, size_t buflen, u32 *result);
 int nvme_set_queue_count(struct nvme_ctrl *ctrl, int *count);
 void nvme_start_keep_alive(struct nvme_ctrl *ctrl);
 void nvme_stop_keep_alive(struct nvme_ctrl *ctrl);
@@ -307,20 +308,35 @@
 
 #ifdef CONFIG_NVM
 int nvme_nvm_ns_supported(struct nvme_ns *ns, struct nvme_id_ns *id);
-int nvme_nvm_register(struct request_queue *q, char *disk_name);
-void nvme_nvm_unregister(struct request_queue *q, char *disk_name);
+int nvme_nvm_register(struct nvme_ns *ns, char *disk_name, int node,
+		      const struct attribute_group *attrs);
+void nvme_nvm_unregister(struct nvme_ns *ns);
+
+static inline struct nvme_ns *nvme_get_ns_from_dev(struct device *dev)
+{
+	if (dev->type->devnode)
+		return dev_to_disk(dev)->private_data;
+
+	return (container_of(dev, struct nvm_dev, dev))->private_data;
+}
 #else
-static inline int nvme_nvm_register(struct request_queue *q, char *disk_name)
+static inline int nvme_nvm_register(struct nvme_ns *ns, char *disk_name,
+				    int node,
+				    const struct attribute_group *attrs)
 {
 	return 0;
 }
 
-static inline void nvme_nvm_unregister(struct request_queue *q, char *disk_name) {};
+static inline void nvme_nvm_unregister(struct nvme_ns *ns) {};
 
 static inline int nvme_nvm_ns_supported(struct nvme_ns *ns, struct nvme_id_ns *id)
 {
 	return 0;
 }
+static inline struct nvme_ns *nvme_get_ns_from_dev(struct device *dev)
+{
+	return dev_to_disk(dev)->private_data;
+}
 #endif /* CONFIG_NVM */
 
 int __init nvme_core_init(void);
diff --git a/drivers/nvme/host/scsi.c b/drivers/nvme/host/scsi.c
index e947e29..c2a0a1c7 100644
--- a/drivers/nvme/host/scsi.c
+++ b/drivers/nvme/host/scsi.c
@@ -72,15 +72,6 @@
 #define ALL_LUNS_RETURNED				0x02
 #define ALL_WELL_KNOWN_LUNS_RETURNED			0x01
 #define RESTRICTED_LUNS_RETURNED			0x00
-#define NVME_POWER_STATE_START_VALID			0x00
-#define NVME_POWER_STATE_ACTIVE				0x01
-#define NVME_POWER_STATE_IDLE				0x02
-#define NVME_POWER_STATE_STANDBY			0x03
-#define NVME_POWER_STATE_LU_CONTROL			0x07
-#define POWER_STATE_0					0
-#define POWER_STATE_1					1
-#define POWER_STATE_2					2
-#define POWER_STATE_3					3
 #define DOWNLOAD_SAVE_ACTIVATE				0x05
 #define DOWNLOAD_SAVE_DEFER_ACTIVATE			0x0E
 #define ACTIVATE_DEFERRED_MICROCODE			0x0F
@@ -915,7 +906,7 @@
 	kfree(smart_log);
 
 	/* Get Features for Temp Threshold */
-	res = nvme_get_features(ns->ctrl, NVME_FEAT_TEMP_THRESH, 0, 0,
+	res = nvme_get_features(ns->ctrl, NVME_FEAT_TEMP_THRESH, 0, NULL, 0,
 								&feature_resp);
 	if (res != NVME_SC_SUCCESS)
 		temp_c_thresh = LOG_TEMP_UNKNOWN;
@@ -1048,7 +1039,7 @@
 	if (len < MODE_PAGE_CACHING_LEN)
 		return -EINVAL;
 
-	nvme_sc = nvme_get_features(ns->ctrl, NVME_FEAT_VOLATILE_WC, 0, 0,
+	nvme_sc = nvme_get_features(ns->ctrl, NVME_FEAT_VOLATILE_WC, 0, NULL, 0,
 								&feature_resp);
 	res = nvme_trans_status_code(hdr, nvme_sc);
 	if (res)
@@ -1229,64 +1220,6 @@
 
 /* Start Stop Unit Helper Functions */
 
-static int nvme_trans_power_state(struct nvme_ns *ns, struct sg_io_hdr *hdr,
-						u8 pc, u8 pcmod, u8 start)
-{
-	int res;
-	int nvme_sc;
-	struct nvme_id_ctrl *id_ctrl;
-	int lowest_pow_st;	/* max npss = lowest power consumption */
-	unsigned ps_desired = 0;
-
-	nvme_sc = nvme_identify_ctrl(ns->ctrl, &id_ctrl);
-	res = nvme_trans_status_code(hdr, nvme_sc);
-	if (res)
-		return res;
-
-	lowest_pow_st = max(POWER_STATE_0, (int)(id_ctrl->npss - 1));
-	kfree(id_ctrl);
-
-	switch (pc) {
-	case NVME_POWER_STATE_START_VALID:
-		/* Action unspecified if POWER CONDITION MODIFIER != 0 */
-		if (pcmod == 0 && start == 0x1)
-			ps_desired = POWER_STATE_0;
-		if (pcmod == 0 && start == 0x0)
-			ps_desired = lowest_pow_st;
-		break;
-	case NVME_POWER_STATE_ACTIVE:
-		/* Action unspecified if POWER CONDITION MODIFIER != 0 */
-		if (pcmod == 0)
-			ps_desired = POWER_STATE_0;
-		break;
-	case NVME_POWER_STATE_IDLE:
-		/* Action unspecified if POWER CONDITION MODIFIER != [0,1,2] */
-		if (pcmod == 0x0)
-			ps_desired = POWER_STATE_1;
-		else if (pcmod == 0x1)
-			ps_desired = POWER_STATE_2;
-		else if (pcmod == 0x2)
-			ps_desired = POWER_STATE_3;
-		break;
-	case NVME_POWER_STATE_STANDBY:
-		/* Action unspecified if POWER CONDITION MODIFIER != [0,1] */
-		if (pcmod == 0x0)
-			ps_desired = max(POWER_STATE_0, (lowest_pow_st - 2));
-		else if (pcmod == 0x1)
-			ps_desired = max(POWER_STATE_0, (lowest_pow_st - 1));
-		break;
-	case NVME_POWER_STATE_LU_CONTROL:
-	default:
-		res = nvme_trans_completion(hdr, SAM_STAT_CHECK_CONDITION,
-				ILLEGAL_REQUEST, SCSI_ASC_INVALID_CDB,
-				SCSI_ASCQ_CAUSE_NOT_REPORTABLE);
-		break;
-	}
-	nvme_sc = nvme_set_features(ns->ctrl, NVME_FEAT_POWER_MGMT, ps_desired, 0,
-				    NULL);
-	return nvme_trans_status_code(hdr, nvme_sc);
-}
-
 static int nvme_trans_send_activate_fw_cmd(struct nvme_ns *ns, struct sg_io_hdr *hdr,
 					u8 buffer_id)
 {
@@ -1395,7 +1328,7 @@
 	case MODE_PAGE_CACHING:
 		dword11 = ((mode_page[2] & CACHING_MODE_PAGE_WCE_MASK) ? 1 : 0);
 		nvme_sc = nvme_set_features(ns->ctrl, NVME_FEAT_VOLATILE_WC,
-					    dword11, 0, NULL);
+					    dword11, NULL, 0, NULL);
 		res = nvme_trans_status_code(hdr, nvme_sc);
 		break;
 	case MODE_PAGE_CONTROL:
@@ -2235,11 +2168,10 @@
 static int nvme_trans_start_stop(struct nvme_ns *ns, struct sg_io_hdr *hdr,
 							u8 *cmd)
 {
-	u8 immed, pcmod, pc, no_flush, start;
+	u8 immed, pcmod, no_flush, start;
 
 	immed = cmd[1] & 0x01;
 	pcmod = cmd[3] & 0x0f;
-	pc = (cmd[4] & 0xf0) >> 4;
 	no_flush = cmd[4] & 0x04;
 	start = cmd[4] & 0x01;
 
@@ -2254,8 +2186,8 @@
 			if (res)
 				return res;
 		}
-		/* Setup the expected power state transition */
-		return nvme_trans_power_state(ns, hdr, pc, pcmod, start);
+
+		return 0;
 	}
 }
 
diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
index 47c564b..7ab9c93 100644
--- a/drivers/nvme/target/admin-cmd.c
+++ b/drivers/nvme/target/admin-cmd.c
@@ -14,6 +14,7 @@
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 #include <linux/module.h>
 #include <generated/utsrelease.h>
+#include <asm/unaligned.h>
 #include "nvmet.h"
 
 u32 nvmet_get_log_page_len(struct nvme_command *cmd)
@@ -29,8 +30,84 @@
 	return len;
 }
 
+static u16 nvmet_get_smart_log_nsid(struct nvmet_req *req,
+		struct nvme_smart_log *slog)
+{
+	u16 status;
+	struct nvmet_ns *ns;
+	u64 host_reads, host_writes, data_units_read, data_units_written;
+
+	status = NVME_SC_SUCCESS;
+	ns = nvmet_find_namespace(req->sq->ctrl, req->cmd->get_log_page.nsid);
+	if (!ns) {
+		status = NVME_SC_INVALID_NS;
+		pr_err("nvmet : Counld not find namespace id : %d\n",
+				le32_to_cpu(req->cmd->get_log_page.nsid));
+		goto out;
+	}
+
+	host_reads = part_stat_read(ns->bdev->bd_part, ios[READ]);
+	data_units_read = part_stat_read(ns->bdev->bd_part, sectors[READ]);
+	host_writes = part_stat_read(ns->bdev->bd_part, ios[WRITE]);
+	data_units_written = part_stat_read(ns->bdev->bd_part, sectors[WRITE]);
+
+	put_unaligned_le64(host_reads, &slog->host_reads[0]);
+	put_unaligned_le64(data_units_read, &slog->data_units_read[0]);
+	put_unaligned_le64(host_writes, &slog->host_writes[0]);
+	put_unaligned_le64(data_units_written, &slog->data_units_written[0]);
+	nvmet_put_namespace(ns);
+out:
+	return status;
+}
+
+static u16 nvmet_get_smart_log_all(struct nvmet_req *req,
+		struct nvme_smart_log *slog)
+{
+	u16 status;
+	u64 host_reads = 0, host_writes = 0;
+	u64 data_units_read = 0, data_units_written = 0;
+	struct nvmet_ns *ns;
+	struct nvmet_ctrl *ctrl;
+
+	status = NVME_SC_SUCCESS;
+	ctrl = req->sq->ctrl;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(ns, &ctrl->subsys->namespaces, dev_link) {
+		host_reads += part_stat_read(ns->bdev->bd_part, ios[READ]);
+		data_units_read +=
+			part_stat_read(ns->bdev->bd_part, sectors[READ]);
+		host_writes += part_stat_read(ns->bdev->bd_part, ios[WRITE]);
+		data_units_written +=
+			part_stat_read(ns->bdev->bd_part, sectors[WRITE]);
+
+	}
+	rcu_read_unlock();
+
+	put_unaligned_le64(host_reads, &slog->host_reads[0]);
+	put_unaligned_le64(data_units_read, &slog->data_units_read[0]);
+	put_unaligned_le64(host_writes, &slog->host_writes[0]);
+	put_unaligned_le64(data_units_written, &slog->data_units_written[0]);
+
+	return status;
+}
+
+static u16 nvmet_get_smart_log(struct nvmet_req *req,
+		struct nvme_smart_log *slog)
+{
+	u16 status;
+
+	WARN_ON(req == NULL || slog == NULL);
+	if (req->cmd->get_log_page.nsid == 0xFFFFFFFF)
+		status = nvmet_get_smart_log_all(req, slog);
+	else
+		status = nvmet_get_smart_log_nsid(req, slog);
+	return status;
+}
+
 static void nvmet_execute_get_log_page(struct nvmet_req *req)
 {
+	struct nvme_smart_log *smart_log;
 	size_t data_len = nvmet_get_log_page_len(req->cmd);
 	void *buf;
 	u16 status = 0;
@@ -59,6 +136,16 @@
 		 * available (e.g. units or commands read/written) those aren't
 		 * persistent over power loss.
 		 */
+		if (data_len != sizeof(*smart_log)) {
+			status = NVME_SC_INTERNAL;
+			goto err;
+		}
+		smart_log = buf;
+		status = nvmet_get_smart_log(req, smart_log);
+		if (status) {
+			memset(buf, '\0', data_len);
+			goto err;
+		}
 		break;
 	case 0x03:
 		/*
@@ -73,6 +160,7 @@
 
 	status = nvmet_copy_to_sgl(req, 0, buf, data_len);
 
+err:
 	kfree(buf);
 out:
 	nvmet_req_complete(req, status);
diff --git a/drivers/nvme/target/io-cmd.c b/drivers/nvme/target/io-cmd.c
index 2cd069b6..4a96c20 100644
--- a/drivers/nvme/target/io-cmd.c
+++ b/drivers/nvme/target/io-cmd.c
@@ -58,6 +58,7 @@
 
 	if (req->cmd->rw.opcode == nvme_cmd_write) {
 		op = REQ_OP_WRITE;
+		op_flags = WRITE_ODIRECT;
 		if (req->cmd->rw.control & cpu_to_le16(NVME_RW_FUA))
 			op_flags |= REQ_FUA;
 	} else {
@@ -205,7 +206,7 @@
 		return 0;
 	case nvme_cmd_dsm:
 		req->execute = nvmet_execute_dsm;
-		req->data_len = le32_to_cpu(cmd->dsm.nr) *
+		req->data_len = le32_to_cpu(cmd->dsm.nr + 1) *
 			sizeof(struct nvme_dsm_range);
 		return 0;
 	default:
diff --git a/fs/befs/linuxvfs.c b/fs/befs/linuxvfs.c
index 7da05b1..bfe9f99 100644
--- a/fs/befs/linuxvfs.c
+++ b/fs/befs/linuxvfs.c
@@ -789,7 +789,7 @@
 	 * Will be set to real fs blocksize later.
 	 *
 	 * Linux 2.4.10 and later refuse to read blocks smaller than
-	 * the hardsect size for the device. But we also need to read at 
+	 * the logical block size for the device. But we also need to read at
 	 * least 1k to get the second 512 bytes of the volume.
 	 * -WD 10-26-01
 	 */ 
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 08ae993..376e4e4 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -180,9 +180,6 @@
 	struct file *file = iocb->ki_filp;
 	struct inode *inode = bdev_file_inode(file);
 
-	if (IS_DAX(inode))
-		return dax_do_io(iocb, inode, iter, blkdev_get_block,
-				NULL, DIO_SKIP_DIO_COUNT);
 	return __blockdev_direct_IO(iocb, inode, I_BDEV(inode), iter,
 				    blkdev_get_block, NULL, NULL,
 				    DIO_SKIP_DIO_COUNT);
@@ -302,14 +299,11 @@
 		error = sb->s_op->thaw_super(sb);
 	else
 		error = thaw_super(sb);
-	if (error) {
+	if (error)
 		bdev->bd_fsfreeze_count++;
-		mutex_unlock(&bdev->bd_fsfreeze_mutex);
-		return error;
-	}
 out:
 	mutex_unlock(&bdev->bd_fsfreeze_mutex);
-	return 0;
+	return error;
 }
 EXPORT_SYMBOL(thaw_bdev);
 
@@ -1275,7 +1269,6 @@
 		bdev->bd_disk = disk;
 		bdev->bd_queue = disk->queue;
 		bdev->bd_contains = bdev;
-		bdev->bd_inode->i_flags = 0;
 
 		if (!partno) {
 			ret = -ENXIO;
@@ -1303,11 +1296,8 @@
 				}
 			}
 
-			if (!ret) {
+			if (!ret)
 				bd_set_size(bdev,(loff_t)get_capacity(disk)<<9);
-				if (!bdev_dax_capable(bdev))
-					bdev->bd_inode->i_flags &= ~S_DAX;
-			}
 
 			/*
 			 * If the device is invalidated, rescan partition
@@ -1342,8 +1332,6 @@
 				goto out_clear;
 			}
 			bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9);
-			if (!bdev_dax_capable(bdev))
-				bdev->bd_inode->i_flags &= ~S_DAX;
 		}
 	} else {
 		if (bdev->bd_contains == bdev) {
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index e6811c42..ca01106 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -8412,7 +8412,7 @@
 	if (!bio)
 		return -ENOMEM;
 
-	bio_set_op_attrs(bio, bio_op(orig_bio), orig_bio->bi_opf);
+	bio_set_op_attrs(bio, bio_op(orig_bio), bio_flags(orig_bio));
 	bio->bi_private = dip;
 	bio->bi_end_io = btrfs_end_dio_bio;
 	btrfs_io_bio(bio)->logical = file_offset;
@@ -8450,7 +8450,8 @@
 						  start_sector, GFP_NOFS);
 			if (!bio)
 				goto out_err;
-			bio_set_op_attrs(bio, bio_op(orig_bio), orig_bio->bi_opf);
+			bio_set_op_attrs(bio, bio_op(orig_bio),
+					 bio_flags(orig_bio));
 			bio->bi_private = dip;
 			bio->bi_end_io = btrfs_end_dio_bio;
 			btrfs_io_bio(bio)->logical = file_offset;
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 23ddf4b..97cb48f 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -1,6 +1,4 @@
 /*
- * 2.5 block I/O model
- *
  * Copyright (C) 2001 Jens Axboe <axboe@suse.de>
  *
  * This program is free software; you can redistribute it and/or modify
@@ -461,6 +459,7 @@
 
 extern void bio_copy_data(struct bio *dst, struct bio *src);
 extern int bio_alloc_pages(struct bio *bio, gfp_t gfp);
+extern void bio_free_pages(struct bio *bio);
 
 extern struct bio *bio_copy_user_iov(struct request_queue *,
 				     struct rq_map_data *,
diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index 10648e3..cbdbf34 100644
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -45,7 +45,7 @@
 	spinlock_t			lock;
 
 	struct radix_tree_root		blkg_tree;
-	struct blkcg_gq			*blkg_hint;
+	struct blkcg_gq	__rcu		*blkg_hint;
 	struct hlist_head		blkg_list;
 
 	struct blkcg_policy_data	*cpd[BLKCG_MAX_POLS];
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index e43bbff..5daa0ef 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -2,6 +2,7 @@
 #define BLK_MQ_H
 
 #include <linux/blkdev.h>
+#include <linux/sbitmap.h>
 
 struct blk_mq_tags;
 struct blk_flush_queue;
@@ -12,21 +13,14 @@
 	int (*notify)(void *data, unsigned long action, unsigned int cpu);
 };
 
-struct blk_mq_ctxmap {
-	unsigned int size;
-	unsigned int bits_per_word;
-	struct blk_align_bitmap *map;
-};
-
 struct blk_mq_hw_ctx {
 	struct {
 		spinlock_t		lock;
 		struct list_head	dispatch;
+		unsigned long		state;		/* BLK_MQ_S_* flags */
 	} ____cacheline_aligned_in_smp;
 
-	unsigned long		state;		/* BLK_MQ_S_* flags */
-	struct delayed_work	run_work;
-	struct delayed_work	delay_work;
+	struct work_struct	run_work;
 	cpumask_var_t		cpumask;
 	int			next_cpu;
 	int			next_cpu_batch;
@@ -38,10 +32,10 @@
 
 	void			*driver_data;
 
-	struct blk_mq_ctxmap	ctx_map;
+	struct sbitmap		ctx_map;
 
-	unsigned int		nr_ctx;
 	struct blk_mq_ctx	**ctxs;
+	unsigned int		nr_ctx;
 
 	atomic_t		wait_index;
 
@@ -49,7 +43,7 @@
 
 	unsigned long		queued;
 	unsigned long		run;
-#define BLK_MQ_MAX_DISPATCH_ORDER	10
+#define BLK_MQ_MAX_DISPATCH_ORDER	7
 	unsigned long		dispatched[BLK_MQ_MAX_DISPATCH_ORDER];
 
 	unsigned int		numa_node;
@@ -57,9 +51,12 @@
 
 	atomic_t		nr_active;
 
+	struct delayed_work	delay_work;
+
 	struct blk_mq_cpu_notifier	cpu_notifier;
 	struct kobject		kobj;
 
+	unsigned long		poll_considered;
 	unsigned long		poll_invoked;
 	unsigned long		poll_success;
 };
@@ -158,6 +155,7 @@
 	BLK_MQ_F_TAG_SHARED	= 1 << 1,
 	BLK_MQ_F_SG_MERGE	= 1 << 2,
 	BLK_MQ_F_DEFER_ISSUE	= 1 << 4,
+	BLK_MQ_F_BLOCKING	= 1 << 5,
 	BLK_MQ_F_ALLOC_POLICY_START_BIT = 8,
 	BLK_MQ_F_ALLOC_POLICY_BITS = 1,
 
@@ -178,8 +176,8 @@
 struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *);
 struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
 						  struct request_queue *q);
-int blk_mq_register_disk(struct gendisk *);
-void blk_mq_unregister_disk(struct gendisk *);
+int blk_mq_register_dev(struct device *, struct request_queue *);
+void blk_mq_unregister_dev(struct device *, struct request_queue *);
 
 int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set);
 void blk_mq_free_tag_set(struct blk_mq_tag_set *set);
@@ -221,7 +219,6 @@
 }
 
 struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *, const int ctx_index);
-struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_tag_set *, unsigned int, int);
 
 int blk_mq_request_started(struct request *rq);
 void blk_mq_start_request(struct request *rq);
@@ -232,6 +229,7 @@
 void blk_mq_add_to_requeue_list(struct request *rq, bool at_head);
 void blk_mq_cancel_requeue_work(struct request_queue *q);
 void blk_mq_kick_requeue_list(struct request_queue *q);
+void blk_mq_delay_kick_requeue_list(struct request_queue *q, unsigned long msecs);
 void blk_mq_abort_requeue_list(struct request_queue *q);
 void blk_mq_complete_request(struct request *rq, int error);
 
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 436f43f..cd395ec 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -16,7 +16,6 @@
 struct io_context;
 struct cgroup_subsys_state;
 typedef void (bio_end_io_t) (struct bio *);
-typedef void (bio_destructor_t) (struct bio *);
 
 #ifdef CONFIG_BLOCK
 /*
@@ -89,14 +88,22 @@
 	struct bio_vec		bi_inline_vecs[0];
 };
 
-#define BIO_OP_SHIFT	(8 * sizeof(unsigned int) - REQ_OP_BITS)
+#define BIO_OP_SHIFT	(8 * FIELD_SIZEOF(struct bio, bi_opf) - REQ_OP_BITS)
+#define bio_flags(bio)	((bio)->bi_opf & ((1 << BIO_OP_SHIFT) - 1))
 #define bio_op(bio)	((bio)->bi_opf >> BIO_OP_SHIFT)
 
-#define bio_set_op_attrs(bio, op, op_flags) do {		\
-	WARN_ON(op >= (1 << REQ_OP_BITS));			\
-	(bio)->bi_opf &= ((1 << BIO_OP_SHIFT) - 1);		\
-	(bio)->bi_opf |= ((unsigned int) (op) << BIO_OP_SHIFT);	\
-	(bio)->bi_opf |= op_flags;				\
+#define bio_set_op_attrs(bio, op, op_flags) do {			\
+	if (__builtin_constant_p(op))					\
+		BUILD_BUG_ON((op) + 0U >= (1U << REQ_OP_BITS));		\
+	else								\
+		WARN_ON_ONCE((op) + 0U >= (1U << REQ_OP_BITS));		\
+	if (__builtin_constant_p(op_flags))				\
+		BUILD_BUG_ON((op_flags) + 0U >= (1U << BIO_OP_SHIFT));	\
+	else								\
+		WARN_ON_ONCE((op_flags) + 0U >= (1U << BIO_OP_SHIFT));	\
+	(bio)->bi_opf = bio_flags(bio);					\
+	(bio)->bi_opf |= (((op) + 0U) << BIO_OP_SHIFT);			\
+	(bio)->bi_opf |= (op_flags);					\
 } while (0)
 
 #define BIO_RESET_BYTES		offsetof(struct bio, bi_max_vecs)
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index e79055c..c47c358 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -449,7 +449,7 @@
 
 	struct list_head	requeue_list;
 	spinlock_t		requeue_lock;
-	struct work_struct	requeue_work;
+	struct delayed_work	requeue_work;
 
 	struct mutex		sysfs_lock;
 
@@ -1440,8 +1440,8 @@
 	return bio_will_gap(req->q, bio, req->bio);
 }
 
-struct work_struct;
 int kblockd_schedule_work(struct work_struct *work);
+int kblockd_schedule_work_on(int cpu, struct work_struct *work);
 int kblockd_schedule_delayed_work(struct delayed_work *dwork, unsigned long delay);
 int kblockd_schedule_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay);
 
diff --git a/include/linux/ioprio.h b/include/linux/ioprio.h
index beb9ce1..8c12390 100644
--- a/include/linux/ioprio.h
+++ b/include/linux/ioprio.h
@@ -7,7 +7,6 @@
 /*
  * Gives us 8 prio classes with 13-bits of data for each class
  */
-#define IOPRIO_BITS		(16)
 #define IOPRIO_CLASS_SHIFT	(13)
 #define IOPRIO_PRIO_MASK	((1UL << IOPRIO_CLASS_SHIFT) - 1)
 
diff --git a/include/linux/lightnvm.h b/include/linux/lightnvm.h
index ba78b83..d190786 100644
--- a/include/linux/lightnvm.h
+++ b/include/linux/lightnvm.h
@@ -352,7 +352,10 @@
 
 	/* Backend device */
 	struct request_queue *q;
+	struct device dev;
+	struct device *parent_dev;
 	char name[DISK_NAME_LEN];
+	void *private_data;
 
 	struct mutex mlock;
 	spinlock_t lock;
@@ -524,9 +527,9 @@
 								unsigned long);
 extern void nvm_put_blk(struct nvm_dev *, struct nvm_block *);
 
-extern int nvm_register(struct request_queue *, char *,
-						struct nvm_dev_ops *);
-extern void nvm_unregister(char *);
+extern struct nvm_dev *nvm_alloc_dev(int);
+extern int nvm_register(struct nvm_dev *);
+extern void nvm_unregister(struct nvm_dev *);
 
 void nvm_mark_blk(struct nvm_dev *dev, struct ppa_addr ppa, int type);
 
@@ -575,11 +578,14 @@
 #else /* CONFIG_NVM */
 struct nvm_dev_ops;
 
-static inline int nvm_register(struct request_queue *q, char *disk_name,
-							struct nvm_dev_ops *ops)
+static inline struct nvm_dev *nvm_alloc_dev(int node)
+{
+	return ERR_PTR(-EINVAL);
+}
+static inline int nvm_register(struct nvm_dev *dev)
 {
 	return -EINVAL;
 }
-static inline void nvm_unregister(char *disk_name) {}
+static inline void nvm_unregister(struct nvm_dev *dev) {}
 #endif /* CONFIG_NVM */
 #endif /* LIGHTNVM.H */
diff --git a/include/linux/sbitmap.h b/include/linux/sbitmap.h
new file mode 100644
index 0000000..f017fd6
--- /dev/null
+++ b/include/linux/sbitmap.h
@@ -0,0 +1,373 @@
+/*
+ * Fast and scalable bitmaps.
+ *
+ * Copyright (C) 2016 Facebook
+ * Copyright (C) 2013-2014 Jens Axboe
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __LINUX_SCALE_BITMAP_H
+#define __LINUX_SCALE_BITMAP_H
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+
+/**
+ * struct sbitmap_word - Word in a &struct sbitmap.
+ */
+struct sbitmap_word {
+	/**
+	 * @word: The bitmap word itself.
+	 */
+	unsigned long word;
+
+	/**
+	 * @depth: Number of bits being used in @word.
+	 */
+	unsigned long depth;
+} ____cacheline_aligned_in_smp;
+
+/**
+ * struct sbitmap - Scalable bitmap.
+ *
+ * A &struct sbitmap is spread over multiple cachelines to avoid ping-pong. This
+ * trades off higher memory usage for better scalability.
+ */
+struct sbitmap {
+	/**
+	 * @depth: Number of bits used in the whole bitmap.
+	 */
+	unsigned int depth;
+
+	/**
+	 * @shift: log2(number of bits used per word)
+	 */
+	unsigned int shift;
+
+	/**
+	 * @map_nr: Number of words (cachelines) being used for the bitmap.
+	 */
+	unsigned int map_nr;
+
+	/**
+	 * @map: Allocated bitmap.
+	 */
+	struct sbitmap_word *map;
+};
+
+#define SBQ_WAIT_QUEUES 8
+#define SBQ_WAKE_BATCH 8
+
+/**
+ * struct sbq_wait_state - Wait queue in a &struct sbitmap_queue.
+ */
+struct sbq_wait_state {
+	/**
+	 * @wait_cnt: Number of frees remaining before we wake up.
+	 */
+	atomic_t wait_cnt;
+
+	/**
+	 * @wait: Wait queue.
+	 */
+	wait_queue_head_t wait;
+} ____cacheline_aligned_in_smp;
+
+/**
+ * struct sbitmap_queue - Scalable bitmap with the added ability to wait on free
+ * bits.
+ *
+ * A &struct sbitmap_queue uses multiple wait queues and rolling wakeups to
+ * avoid contention on the wait queue spinlock. This ensures that we don't hit a
+ * scalability wall when we run out of free bits and have to start putting tasks
+ * to sleep.
+ */
+struct sbitmap_queue {
+	/**
+	 * @sb: Scalable bitmap.
+	 */
+	struct sbitmap sb;
+
+	/*
+	 * @alloc_hint: Cache of last successfully allocated or freed bit.
+	 *
+	 * This is per-cpu, which allows multiple users to stick to different
+	 * cachelines until the map is exhausted.
+	 */
+	unsigned int __percpu *alloc_hint;
+
+	/**
+	 * @wake_batch: Number of bits which must be freed before we wake up any
+	 * waiters.
+	 */
+	unsigned int wake_batch;
+
+	/**
+	 * @wake_index: Next wait queue in @ws to wake up.
+	 */
+	atomic_t wake_index;
+
+	/**
+	 * @ws: Wait queues.
+	 */
+	struct sbq_wait_state *ws;
+
+	/**
+	 * @round_robin: Allocate bits in strict round-robin order.
+	 */
+	bool round_robin;
+};
+
+/**
+ * sbitmap_init_node() - Initialize a &struct sbitmap on a specific memory node.
+ * @sb: Bitmap to initialize.
+ * @depth: Number of bits to allocate.
+ * @shift: Use 2^@shift bits per word in the bitmap; if a negative number if
+ *         given, a good default is chosen.
+ * @flags: Allocation flags.
+ * @node: Memory node to allocate on.
+ *
+ * Return: Zero on success or negative errno on failure.
+ */
+int sbitmap_init_node(struct sbitmap *sb, unsigned int depth, int shift,
+		      gfp_t flags, int node);
+
+/**
+ * sbitmap_free() - Free memory used by a &struct sbitmap.
+ * @sb: Bitmap to free.
+ */
+static inline void sbitmap_free(struct sbitmap *sb)
+{
+	kfree(sb->map);
+	sb->map = NULL;
+}
+
+/**
+ * sbitmap_resize() - Resize a &struct sbitmap.
+ * @sb: Bitmap to resize.
+ * @depth: New number of bits to resize to.
+ *
+ * Doesn't reallocate anything. It's up to the caller to ensure that the new
+ * depth doesn't exceed the depth that the sb was initialized with.
+ */
+void sbitmap_resize(struct sbitmap *sb, unsigned int depth);
+
+/**
+ * sbitmap_get() - Try to allocate a free bit from a &struct sbitmap.
+ * @sb: Bitmap to allocate from.
+ * @alloc_hint: Hint for where to start searching for a free bit.
+ * @round_robin: If true, be stricter about allocation order; always allocate
+ *               starting from the last allocated bit. This is less efficient
+ *               than the default behavior (false).
+ *
+ * Return: Non-negative allocated bit number if successful, -1 otherwise.
+ */
+int sbitmap_get(struct sbitmap *sb, unsigned int alloc_hint, bool round_robin);
+
+/**
+ * sbitmap_any_bit_set() - Check for a set bit in a &struct sbitmap.
+ * @sb: Bitmap to check.
+ *
+ * Return: true if any bit in the bitmap is set, false otherwise.
+ */
+bool sbitmap_any_bit_set(const struct sbitmap *sb);
+
+/**
+ * sbitmap_any_bit_clear() - Check for an unset bit in a &struct
+ * sbitmap.
+ * @sb: Bitmap to check.
+ *
+ * Return: true if any bit in the bitmap is clear, false otherwise.
+ */
+bool sbitmap_any_bit_clear(const struct sbitmap *sb);
+
+typedef bool (*sb_for_each_fn)(struct sbitmap *, unsigned int, void *);
+
+/**
+ * sbitmap_for_each_set() - Iterate over each set bit in a &struct sbitmap.
+ * @sb: Bitmap to iterate over.
+ * @fn: Callback. Should return true to continue or false to break early.
+ * @data: Pointer to pass to callback.
+ *
+ * This is inline even though it's non-trivial so that the function calls to the
+ * callback will hopefully get optimized away.
+ */
+static inline void sbitmap_for_each_set(struct sbitmap *sb, sb_for_each_fn fn,
+					void *data)
+{
+	unsigned int i;
+
+	for (i = 0; i < sb->map_nr; i++) {
+		struct sbitmap_word *word = &sb->map[i];
+		unsigned int off, nr;
+
+		if (!word->word)
+			continue;
+
+		nr = 0;
+		off = i << sb->shift;
+		while (1) {
+			nr = find_next_bit(&word->word, word->depth, nr);
+			if (nr >= word->depth)
+				break;
+
+			if (!fn(sb, off + nr, data))
+				return;
+
+			nr++;
+		}
+	}
+}
+
+#define SB_NR_TO_INDEX(sb, bitnr) ((bitnr) >> (sb)->shift)
+#define SB_NR_TO_BIT(sb, bitnr) ((bitnr) & ((1U << (sb)->shift) - 1U))
+
+static inline unsigned long *__sbitmap_word(struct sbitmap *sb,
+					    unsigned int bitnr)
+{
+	return &sb->map[SB_NR_TO_INDEX(sb, bitnr)].word;
+}
+
+/* Helpers equivalent to the operations in asm/bitops.h and linux/bitmap.h */
+
+static inline void sbitmap_set_bit(struct sbitmap *sb, unsigned int bitnr)
+{
+	set_bit(SB_NR_TO_BIT(sb, bitnr), __sbitmap_word(sb, bitnr));
+}
+
+static inline void sbitmap_clear_bit(struct sbitmap *sb, unsigned int bitnr)
+{
+	clear_bit(SB_NR_TO_BIT(sb, bitnr), __sbitmap_word(sb, bitnr));
+}
+
+static inline int sbitmap_test_bit(struct sbitmap *sb, unsigned int bitnr)
+{
+	return test_bit(SB_NR_TO_BIT(sb, bitnr), __sbitmap_word(sb, bitnr));
+}
+
+unsigned int sbitmap_weight(const struct sbitmap *sb);
+
+/**
+ * sbitmap_queue_init_node() - Initialize a &struct sbitmap_queue on a specific
+ * memory node.
+ * @sbq: Bitmap queue to initialize.
+ * @depth: See sbitmap_init_node().
+ * @shift: See sbitmap_init_node().
+ * @round_robin: See sbitmap_get().
+ * @flags: Allocation flags.
+ * @node: Memory node to allocate on.
+ *
+ * Return: Zero on success or negative errno on failure.
+ */
+int sbitmap_queue_init_node(struct sbitmap_queue *sbq, unsigned int depth,
+			    int shift, bool round_robin, gfp_t flags, int node);
+
+/**
+ * sbitmap_queue_free() - Free memory used by a &struct sbitmap_queue.
+ *
+ * @sbq: Bitmap queue to free.
+ */
+static inline void sbitmap_queue_free(struct sbitmap_queue *sbq)
+{
+	kfree(sbq->ws);
+	free_percpu(sbq->alloc_hint);
+	sbitmap_free(&sbq->sb);
+}
+
+/**
+ * sbitmap_queue_resize() - Resize a &struct sbitmap_queue.
+ * @sbq: Bitmap queue to resize.
+ * @depth: New number of bits to resize to.
+ *
+ * Like sbitmap_resize(), this doesn't reallocate anything. It has to do
+ * some extra work on the &struct sbitmap_queue, so it's not safe to just
+ * resize the underlying &struct sbitmap.
+ */
+void sbitmap_queue_resize(struct sbitmap_queue *sbq, unsigned int depth);
+
+/**
+ * __sbitmap_queue_get() - Try to allocate a free bit from a &struct
+ * sbitmap_queue with preemption already disabled.
+ * @sbq: Bitmap queue to allocate from.
+ *
+ * Return: Non-negative allocated bit number if successful, -1 otherwise.
+ */
+int __sbitmap_queue_get(struct sbitmap_queue *sbq);
+
+/**
+ * sbitmap_queue_get() - Try to allocate a free bit from a &struct
+ * sbitmap_queue.
+ * @sbq: Bitmap queue to allocate from.
+ * @cpu: Output parameter; will contain the CPU we ran on (e.g., to be passed to
+ *       sbitmap_queue_clear()).
+ *
+ * Return: Non-negative allocated bit number if successful, -1 otherwise.
+ */
+static inline int sbitmap_queue_get(struct sbitmap_queue *sbq,
+				    unsigned int *cpu)
+{
+	int nr;
+
+	*cpu = get_cpu();
+	nr = __sbitmap_queue_get(sbq);
+	put_cpu();
+	return nr;
+}
+
+/**
+ * sbitmap_queue_clear() - Free an allocated bit and wake up waiters on a
+ * &struct sbitmap_queue.
+ * @sbq: Bitmap to free from.
+ * @nr: Bit number to free.
+ * @cpu: CPU the bit was allocated on.
+ */
+void sbitmap_queue_clear(struct sbitmap_queue *sbq, unsigned int nr,
+			 unsigned int cpu);
+
+static inline int sbq_index_inc(int index)
+{
+	return (index + 1) & (SBQ_WAIT_QUEUES - 1);
+}
+
+static inline void sbq_index_atomic_inc(atomic_t *index)
+{
+	int old = atomic_read(index);
+	int new = sbq_index_inc(old);
+	atomic_cmpxchg(index, old, new);
+}
+
+/**
+ * sbq_wait_ptr() - Get the next wait queue to use for a &struct
+ * sbitmap_queue.
+ * @sbq: Bitmap queue to wait on.
+ * @wait_index: A counter per "user" of @sbq.
+ */
+static inline struct sbq_wait_state *sbq_wait_ptr(struct sbitmap_queue *sbq,
+						  atomic_t *wait_index)
+{
+	struct sbq_wait_state *ws;
+
+	ws = &sbq->ws[atomic_read(wait_index)];
+	sbq_index_atomic_inc(wait_index);
+	return ws;
+}
+
+/**
+ * sbitmap_queue_wake_all() - Wake up everything waiting on a &struct
+ * sbitmap_queue.
+ * @sbq: Bitmap queue to wake up.
+ */
+void sbitmap_queue_wake_all(struct sbitmap_queue *sbq);
+
+#endif /* __LINUX_SCALE_BITMAP_H */
diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index 26cc1df..fc6e221 100644
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -442,6 +442,7 @@
 int execute_in_process_context(work_func_t fn, struct execute_work *);
 
 extern bool flush_work(struct work_struct *work);
+extern bool cancel_work(struct work_struct *work);
 extern bool cancel_work_sync(struct work_struct *work);
 
 extern bool flush_delayed_work(struct delayed_work *dwork);
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index ef071ca..bd81f03 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -2974,6 +2974,31 @@
 }
 EXPORT_SYMBOL(flush_delayed_work);
 
+static bool __cancel_work(struct work_struct *work, bool is_dwork)
+{
+	unsigned long flags;
+	int ret;
+
+	do {
+		ret = try_to_grab_pending(work, is_dwork, &flags);
+	} while (unlikely(ret == -EAGAIN));
+
+	if (unlikely(ret < 0))
+		return false;
+
+	set_work_pool_and_clear_pending(work, get_work_pool_id(work));
+	local_irq_restore(flags);
+	return ret;
+}
+
+/*
+ * See cancel_delayed_work()
+ */
+bool cancel_work(struct work_struct *work)
+{
+	return __cancel_work(work, false);
+}
+
 /**
  * cancel_delayed_work - cancel a delayed work
  * @dwork: delayed_work to cancel
@@ -2992,20 +3017,7 @@
  */
 bool cancel_delayed_work(struct delayed_work *dwork)
 {
-	unsigned long flags;
-	int ret;
-
-	do {
-		ret = try_to_grab_pending(&dwork->work, true, &flags);
-	} while (unlikely(ret == -EAGAIN));
-
-	if (unlikely(ret < 0))
-		return false;
-
-	set_work_pool_and_clear_pending(&dwork->work,
-					get_work_pool_id(&dwork->work));
-	local_irq_restore(flags);
-	return ret;
+	return __cancel_work(&dwork->work, true);
 }
 EXPORT_SYMBOL(cancel_delayed_work);
 
diff --git a/lib/Kconfig b/lib/Kconfig
index d79909d..942fb80 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -550,4 +550,7 @@
 	bool
 	select STACKTRACE
 
+config SBITMAP
+	bool
+
 endmenu
diff --git a/lib/Makefile b/lib/Makefile
index df747e5..f3ca8c0 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -227,3 +227,5 @@
 obj-$(CONFIG_UBSAN) += ubsan.o
 
 UBSAN_SANITIZE_ubsan.o := n
+
+obj-$(CONFIG_SBITMAP) += sbitmap.o
diff --git a/lib/sbitmap.c b/lib/sbitmap.c
new file mode 100644
index 0000000..2cecf05
--- /dev/null
+++ b/lib/sbitmap.c
@@ -0,0 +1,347 @@
+/*
+ * Copyright (C) 2016 Facebook
+ * Copyright (C) 2013-2014 Jens Axboe
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <linux/random.h>
+#include <linux/sbitmap.h>
+
+int sbitmap_init_node(struct sbitmap *sb, unsigned int depth, int shift,
+		      gfp_t flags, int node)
+{
+	unsigned int bits_per_word;
+	unsigned int i;
+
+	if (shift < 0) {
+		shift = ilog2(BITS_PER_LONG);
+		/*
+		 * If the bitmap is small, shrink the number of bits per word so
+		 * we spread over a few cachelines, at least. If less than 4
+		 * bits, just forget about it, it's not going to work optimally
+		 * anyway.
+		 */
+		if (depth >= 4) {
+			while ((4U << shift) > depth)
+				shift--;
+		}
+	}
+	bits_per_word = 1U << shift;
+	if (bits_per_word > BITS_PER_LONG)
+		return -EINVAL;
+
+	sb->shift = shift;
+	sb->depth = depth;
+	sb->map_nr = DIV_ROUND_UP(sb->depth, bits_per_word);
+
+	if (depth == 0) {
+		sb->map = NULL;
+		return 0;
+	}
+
+	sb->map = kzalloc_node(sb->map_nr * sizeof(*sb->map), flags, node);
+	if (!sb->map)
+		return -ENOMEM;
+
+	for (i = 0; i < sb->map_nr; i++) {
+		sb->map[i].depth = min(depth, bits_per_word);
+		depth -= sb->map[i].depth;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(sbitmap_init_node);
+
+void sbitmap_resize(struct sbitmap *sb, unsigned int depth)
+{
+	unsigned int bits_per_word = 1U << sb->shift;
+	unsigned int i;
+
+	sb->depth = depth;
+	sb->map_nr = DIV_ROUND_UP(sb->depth, bits_per_word);
+
+	for (i = 0; i < sb->map_nr; i++) {
+		sb->map[i].depth = min(depth, bits_per_word);
+		depth -= sb->map[i].depth;
+	}
+}
+EXPORT_SYMBOL_GPL(sbitmap_resize);
+
+static int __sbitmap_get_word(struct sbitmap_word *word, unsigned int hint,
+			      bool wrap)
+{
+	unsigned int orig_hint = hint;
+	int nr;
+
+	while (1) {
+		nr = find_next_zero_bit(&word->word, word->depth, hint);
+		if (unlikely(nr >= word->depth)) {
+			/*
+			 * We started with an offset, and we didn't reset the
+			 * offset to 0 in a failure case, so start from 0 to
+			 * exhaust the map.
+			 */
+			if (orig_hint && hint && wrap) {
+				hint = orig_hint = 0;
+				continue;
+			}
+			return -1;
+		}
+
+		if (!test_and_set_bit(nr, &word->word))
+			break;
+
+		hint = nr + 1;
+		if (hint >= word->depth - 1)
+			hint = 0;
+	}
+
+	return nr;
+}
+
+int sbitmap_get(struct sbitmap *sb, unsigned int alloc_hint, bool round_robin)
+{
+	unsigned int i, index;
+	int nr = -1;
+
+	index = SB_NR_TO_INDEX(sb, alloc_hint);
+
+	for (i = 0; i < sb->map_nr; i++) {
+		nr = __sbitmap_get_word(&sb->map[index],
+					SB_NR_TO_BIT(sb, alloc_hint),
+					!round_robin);
+		if (nr != -1) {
+			nr += index << sb->shift;
+			break;
+		}
+
+		/* Jump to next index. */
+		index++;
+		alloc_hint = index << sb->shift;
+
+		if (index >= sb->map_nr) {
+			index = 0;
+			alloc_hint = 0;
+		}
+	}
+
+	return nr;
+}
+EXPORT_SYMBOL_GPL(sbitmap_get);
+
+bool sbitmap_any_bit_set(const struct sbitmap *sb)
+{
+	unsigned int i;
+
+	for (i = 0; i < sb->map_nr; i++) {
+		if (sb->map[i].word)
+			return true;
+	}
+	return false;
+}
+EXPORT_SYMBOL_GPL(sbitmap_any_bit_set);
+
+bool sbitmap_any_bit_clear(const struct sbitmap *sb)
+{
+	unsigned int i;
+
+	for (i = 0; i < sb->map_nr; i++) {
+		const struct sbitmap_word *word = &sb->map[i];
+		unsigned long ret;
+
+		ret = find_first_zero_bit(&word->word, word->depth);
+		if (ret < word->depth)
+			return true;
+	}
+	return false;
+}
+EXPORT_SYMBOL_GPL(sbitmap_any_bit_clear);
+
+unsigned int sbitmap_weight(const struct sbitmap *sb)
+{
+	unsigned int i, weight = 0;
+
+	for (i = 0; i < sb->map_nr; i++) {
+		const struct sbitmap_word *word = &sb->map[i];
+
+		weight += bitmap_weight(&word->word, word->depth);
+	}
+	return weight;
+}
+EXPORT_SYMBOL_GPL(sbitmap_weight);
+
+static unsigned int sbq_calc_wake_batch(unsigned int depth)
+{
+	unsigned int wake_batch;
+
+	/*
+	 * For each batch, we wake up one queue. We need to make sure that our
+	 * batch size is small enough that the full depth of the bitmap is
+	 * enough to wake up all of the queues.
+	 */
+	wake_batch = SBQ_WAKE_BATCH;
+	if (wake_batch > depth / SBQ_WAIT_QUEUES)
+		wake_batch = max(1U, depth / SBQ_WAIT_QUEUES);
+
+	return wake_batch;
+}
+
+int sbitmap_queue_init_node(struct sbitmap_queue *sbq, unsigned int depth,
+			    int shift, bool round_robin, gfp_t flags, int node)
+{
+	int ret;
+	int i;
+
+	ret = sbitmap_init_node(&sbq->sb, depth, shift, flags, node);
+	if (ret)
+		return ret;
+
+	sbq->alloc_hint = alloc_percpu_gfp(unsigned int, flags);
+	if (!sbq->alloc_hint) {
+		sbitmap_free(&sbq->sb);
+		return -ENOMEM;
+	}
+
+	if (depth && !round_robin) {
+		for_each_possible_cpu(i)
+			*per_cpu_ptr(sbq->alloc_hint, i) = prandom_u32() % depth;
+	}
+
+	sbq->wake_batch = sbq_calc_wake_batch(depth);
+	atomic_set(&sbq->wake_index, 0);
+
+	sbq->ws = kzalloc_node(SBQ_WAIT_QUEUES * sizeof(*sbq->ws), flags, node);
+	if (!sbq->ws) {
+		free_percpu(sbq->alloc_hint);
+		sbitmap_free(&sbq->sb);
+		return -ENOMEM;
+	}
+
+	for (i = 0; i < SBQ_WAIT_QUEUES; i++) {
+		init_waitqueue_head(&sbq->ws[i].wait);
+		atomic_set(&sbq->ws[i].wait_cnt, sbq->wake_batch);
+	}
+
+	sbq->round_robin = round_robin;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(sbitmap_queue_init_node);
+
+void sbitmap_queue_resize(struct sbitmap_queue *sbq, unsigned int depth)
+{
+	sbq->wake_batch = sbq_calc_wake_batch(depth);
+	sbitmap_resize(&sbq->sb, depth);
+}
+EXPORT_SYMBOL_GPL(sbitmap_queue_resize);
+
+int __sbitmap_queue_get(struct sbitmap_queue *sbq)
+{
+	unsigned int hint, depth;
+	int nr;
+
+	hint = this_cpu_read(*sbq->alloc_hint);
+	depth = READ_ONCE(sbq->sb.depth);
+	if (unlikely(hint >= depth)) {
+		hint = depth ? prandom_u32() % depth : 0;
+		this_cpu_write(*sbq->alloc_hint, hint);
+	}
+	nr = sbitmap_get(&sbq->sb, hint, sbq->round_robin);
+
+	if (nr == -1) {
+		/* If the map is full, a hint won't do us much good. */
+		this_cpu_write(*sbq->alloc_hint, 0);
+	} else if (nr == hint || unlikely(sbq->round_robin)) {
+		/* Only update the hint if we used it. */
+		hint = nr + 1;
+		if (hint >= depth - 1)
+			hint = 0;
+		this_cpu_write(*sbq->alloc_hint, hint);
+	}
+
+	return nr;
+}
+EXPORT_SYMBOL_GPL(__sbitmap_queue_get);
+
+static struct sbq_wait_state *sbq_wake_ptr(struct sbitmap_queue *sbq)
+{
+	int i, wake_index;
+
+	wake_index = atomic_read(&sbq->wake_index);
+	for (i = 0; i < SBQ_WAIT_QUEUES; i++) {
+		struct sbq_wait_state *ws = &sbq->ws[wake_index];
+
+		if (waitqueue_active(&ws->wait)) {
+			int o = atomic_read(&sbq->wake_index);
+
+			if (wake_index != o)
+				atomic_cmpxchg(&sbq->wake_index, o, wake_index);
+			return ws;
+		}
+
+		wake_index = sbq_index_inc(wake_index);
+	}
+
+	return NULL;
+}
+
+static void sbq_wake_up(struct sbitmap_queue *sbq)
+{
+	struct sbq_wait_state *ws;
+	int wait_cnt;
+
+	/* Ensure that the wait list checks occur after clear_bit(). */
+	smp_mb();
+
+	ws = sbq_wake_ptr(sbq);
+	if (!ws)
+		return;
+
+	wait_cnt = atomic_dec_return(&ws->wait_cnt);
+	if (unlikely(wait_cnt < 0))
+		wait_cnt = atomic_inc_return(&ws->wait_cnt);
+	if (wait_cnt == 0) {
+		atomic_add(sbq->wake_batch, &ws->wait_cnt);
+		sbq_index_atomic_inc(&sbq->wake_index);
+		wake_up(&ws->wait);
+	}
+}
+
+void sbitmap_queue_clear(struct sbitmap_queue *sbq, unsigned int nr,
+			 unsigned int cpu)
+{
+	sbitmap_clear_bit(&sbq->sb, nr);
+	sbq_wake_up(sbq);
+	if (likely(!sbq->round_robin && nr < sbq->sb.depth))
+		*per_cpu_ptr(sbq->alloc_hint, cpu) = nr;
+}
+EXPORT_SYMBOL_GPL(sbitmap_queue_clear);
+
+void sbitmap_queue_wake_all(struct sbitmap_queue *sbq)
+{
+	int i, wake_index;
+
+	/*
+	 * Make sure all changes prior to this are visible from other CPUs.
+	 */
+	smp_mb();
+	wake_index = atomic_read(&sbq->wake_index);
+	for (i = 0; i < SBQ_WAIT_QUEUES; i++) {
+		struct sbq_wait_state *ws = &sbq->ws[wake_index];
+
+		if (waitqueue_active(&ws->wait))
+			wake_up(&ws->wait);
+
+		wake_index = sbq_index_inc(wake_index);
+	}
+}
+EXPORT_SYMBOL_GPL(sbitmap_queue_wake_all);