[PATCH v4] basic conversion to blk-mq

[PATCH v4] basic conversion to blk-mq

[Matias Bjørling]

Hi Matthew and Keith,

Thanks for the quick review.

The patch has been updated with the feedback from Keith and Jens. It's against
Jens' 3.16/core tree. You may use the nvmemq_wip_review branch at:

https://github.com/MatiasBjorling/linux-collab nvmemq_wip_review

Changes since v3:
  * Added abortion logic
  * Fixed possible race on abortion
  * Removed req data with flush. Handled by by blk-mq
  * Added safety check for submitting user rq to admin queue.
  * Use dev->online_queues for nr_hw_queues
  * Fix loop with initialization in nvme_create_io_queues
  * Style fixups

Changes since v2:
  * rebased on top of current 3.16/core.
  * use blk-mq queue management for spreading io queues
  * removed rcu handling and allocated all io queues up front for mgmt by blk-mq
  * removed the need for hotplugging notification
  * fixed flush data handling
  * fixed double free of spinlock
  * various cleanup

Keith, what kind of retry scheme do you like for timeout retries?

Matias Bjørling (1):
  NVMe: basic conversion to blk-mq

 drivers/block/nvme-core.c | 1100 ++++++++++++++++++---------------------------
 include/linux/nvme.h      |   11 +-
 2 files changed, 442 insertions(+), 669 deletions(-)

-- 
1.9.1

[PATCH v4] NVMe: basic conversion to blk-mq

[Matias Bjørling]

This converts the current NVMe driver to utilize the blk-mq layer.

Contributions in this patch from:

  Sam Bradshaw <sbradshaw@micron.com>
  Jens Axboe <axboe@kernel.dk>

Signed-off-by: Matias Bjørling <m@bjorling.me>
---
 drivers/block/nvme-core.c | 1100 ++++++++++++++++++---------------------------
 include/linux/nvme.h      |   11 +-
 2 files changed, 442 insertions(+), 669 deletions(-)

diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c
index 9212dcc..22d8013 100644
--- a/drivers/block/nvme-core.c
+++ b/drivers/block/nvme-core.c
@@ -13,9 +13,9 @@
  */
 
 #include <linux/nvme.h>
-#include <linux/bio.h>
 #include <linux/bitops.h>
 #include <linux/blkdev.h>
+#include <linux/blk-mq.h>
 #include <linux/cpu.h>
 #include <linux/delay.h>
 #include <linux/errno.h>
@@ -33,7 +33,6 @@
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/pci.h>
-#include <linux/percpu.h>
 #include <linux/poison.h>
 #include <linux/ptrace.h>
 #include <linux/sched.h>
@@ -42,11 +41,11 @@
 #include <scsi/sg.h>
 #include <asm-generic/io-64-nonatomic-lo-hi.h>
 
-#define NVME_Q_DEPTH 1024
+#define NVME_Q_DEPTH		1024
+#define NVME_AQ_DEPTH		64
 #define SQ_SIZE(depth)		(depth * sizeof(struct nvme_command))
 #define CQ_SIZE(depth)		(depth * sizeof(struct nvme_completion))
-#define ADMIN_TIMEOUT	(60 * HZ)
-#define IOD_TIMEOUT	(4 * NVME_IO_TIMEOUT)
+#define ADMIN_TIMEOUT		(60 * HZ)
 
 unsigned char io_timeout = 30;
 module_param(io_timeout, byte, 0644);
@@ -65,10 +64,12 @@ static struct workqueue_struct *nvme_workq;
 static wait_queue_head_t nvme_kthread_wait;
 
 static void nvme_reset_failed_dev(struct work_struct *ws);
+static int nvme_process_cq(struct nvme_queue *nvmeq);
 
 struct async_cmd_info {
 	struct kthread_work work;
 	struct kthread_worker *worker;
+	struct request *req;
 	u32 result;
 	int status;
 	void *ctx;
@@ -79,7 +80,6 @@ struct async_cmd_info {
  * commands and one for I/O commands).
  */
 struct nvme_queue {
-	struct rcu_head r_head;
 	struct device *q_dmadev;
 	struct nvme_dev *dev;
 	char irqname[24];	/* nvme4294967295-65535\0 */
@@ -88,10 +88,6 @@ struct nvme_queue {
 	volatile struct nvme_completion *cqes;
 	dma_addr_t sq_dma_addr;
 	dma_addr_t cq_dma_addr;
-	wait_queue_head_t sq_full;
-	wait_queue_t sq_cong_wait;
-	struct bio_list sq_cong;
-	struct list_head iod_bio;
 	u32 __iomem *q_db;
 	u16 q_depth;
 	u16 cq_vector;
@@ -100,11 +96,10 @@ struct nvme_queue {
 	u16 cq_head;
 	u16 qid;
 	u8 cq_phase;
-	u8 cqe_seen;
 	u8 q_suspended;
 	cpumask_var_t cpu_mask;
 	struct async_cmd_info cmdinfo;
-	unsigned long cmdid_data[];
+	struct blk_mq_hw_ctx *hctx;
 };
 
 /*
@@ -132,62 +127,66 @@ typedef void (*nvme_completion_fn)(struct nvme_queue *, void *,
 struct nvme_cmd_info {
 	nvme_completion_fn fn;
 	void *ctx;
-	unsigned long timeout;
 	int aborted;
+	struct nvme_queue *nvmeq;
 };
 
-static struct nvme_cmd_info *nvme_cmd_info(struct nvme_queue *nvmeq)
+static int nvme_init_admin_hctx(struct blk_mq_hw_ctx *hctx, void *data,
+				unsigned int i)
 {
-	return (void *)&nvmeq->cmdid_data[BITS_TO_LONGS(nvmeq->q_depth)];
+	struct nvme_dev *dev = data;
+	struct nvme_queue *nvmeq = dev->queues[0];
+	BUG_ON(!nvmeq);
+	WARN_ON(nvmeq->hctx);
+	nvmeq->hctx = hctx;
+	hctx->driver_data = nvmeq;
+	return 0;
 }
 
-static unsigned nvme_queue_extra(int depth)
+static int nvme_init_admin_request(void *data, struct request *req,
+				unsigned int hctx_idx, unsigned int rq_idx,
+				unsigned int numa_node)
 {
-	return DIV_ROUND_UP(depth, 8) + (depth * sizeof(struct nvme_cmd_info));
+	struct nvme_dev *dev = data;
+	struct nvme_cmd_info *cmd = blk_mq_rq_to_pdu(req);
+	struct nvme_queue *nvmeq = dev->queues[0];
+	WARN_ON(!nvmeq);
+	WARN_ON(!cmd);
+	cmd->nvmeq = nvmeq;
+	return 0;
 }
 
-/**
- * alloc_cmdid() - Allocate a Command ID
- * @nvmeq: The queue that will be used for this command
- * @ctx: A pointer that will be passed to the handler
- * @handler: The function to call on completion
- *
- * Allocate a Command ID for a queue.  The data passed in will
- * be passed to the completion handler.  This is implemented by using
- * the bottom two bits of the ctx pointer to store the handler ID.
- * Passing in a pointer that's not 4-byte aligned will cause a BUG.
- * We can change this if it becomes a problem.
- *
- * May be called with local interrupts disabled and the q_lock held,
- * or with interrupts enabled and no locks held.
- */
-static int alloc_cmdid(struct nvme_queue *nvmeq, void *ctx,
-				nvme_completion_fn handler, unsigned timeout)
+static int nvme_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
+			  unsigned int i)
 {
-	int depth = nvmeq->q_depth - 1;
-	struct nvme_cmd_info *info = nvme_cmd_info(nvmeq);
-	int cmdid;
-
-	do {
-		cmdid = find_first_zero_bit(nvmeq->cmdid_data, depth);
-		if (cmdid >= depth)
-			return -EBUSY;
-	} while (test_and_set_bit(cmdid, nvmeq->cmdid_data));
+	struct nvme_dev *dev = data;
+	struct nvme_queue *nvmeq = dev->queues[(i % dev->queue_count) + 1];
+	BUG_ON(!nvmeq);
+	WARN_ON(nvmeq->hctx);
+	nvmeq->hctx = hctx;
+	hctx->driver_data = nvmeq;
+	return 0;
+}
 
-	info[cmdid].fn = handler;
-	info[cmdid].ctx = ctx;
-	info[cmdid].timeout = jiffies + timeout;
-	info[cmdid].aborted = 0;
-	return cmdid;
+static int nvme_init_request(void *data, struct request *req,
+				unsigned int hctx_idx, unsigned int rq_idx,
+				unsigned int numa_node)
+{
+	struct nvme_dev *dev = data;
+	struct nvme_cmd_info *cmd = blk_mq_rq_to_pdu(req);
+	struct nvme_queue *nvmeq = dev->queues[hctx_idx + 1];
+	WARN_ON(!nvmeq);
+	WARN_ON(!cmd);
+	cmd->nvmeq = nvmeq;
+	return 0;
 }
 
-static int alloc_cmdid_killable(struct nvme_queue *nvmeq, void *ctx,
-				nvme_completion_fn handler, unsigned timeout)
+static void nvme_set_info(struct nvme_cmd_info *cmd, void *ctx,
+				nvme_completion_fn handler)
 {
-	int cmdid;
-	wait_event_killable(nvmeq->sq_full,
-		(cmdid = alloc_cmdid(nvmeq, ctx, handler, timeout)) >= 0);
-	return (cmdid < 0) ? -EINTR : cmdid;
+	cmd->fn = handler;
+	cmd->ctx = ctx;
+	cmd->aborted = 0;
 }
 
 /* Special values must be less than 0x1000 */
@@ -195,16 +194,13 @@ static int alloc_cmdid_killable(struct nvme_queue *nvmeq, void *ctx,
 #define CMD_CTX_CANCELLED	(0x30C + CMD_CTX_BASE)
 #define CMD_CTX_COMPLETED	(0x310 + CMD_CTX_BASE)
 #define CMD_CTX_INVALID		(0x314 + CMD_CTX_BASE)
-#define CMD_CTX_FLUSH		(0x318 + CMD_CTX_BASE)
-#define CMD_CTX_ABORT		(0x31C + CMD_CTX_BASE)
+#define CMD_CTX_ABORT		(0x318 + CMD_CTX_BASE)
 
 static void special_completion(struct nvme_queue *nvmeq, void *ctx,
 						struct nvme_completion *cqe)
 {
 	if (ctx == CMD_CTX_CANCELLED)
 		return;
-	if (ctx == CMD_CTX_FLUSH)
-		return;
 	if (ctx == CMD_CTX_ABORT) {
 		++nvmeq->dev->abort_limit;
 		return;
@@ -232,75 +228,48 @@ static void async_completion(struct nvme_queue *nvmeq, void *ctx,
 	cmdinfo->result = le32_to_cpup(&cqe->result);
 	cmdinfo->status = le16_to_cpup(&cqe->status) >> 1;
 	queue_kthread_work(cmdinfo->worker, &cmdinfo->work);
+	blk_put_request(cmdinfo->req);
+}
+
+static inline struct nvme_cmd_info *get_cmd_from_tag(struct nvme_queue *nvmeq,
+				  unsigned int tag)
+{
+	struct blk_mq_hw_ctx *hctx = nvmeq->hctx;
+	struct request *req = blk_mq_tag_to_rq(hctx->tags, tag);
+	return blk_mq_rq_to_pdu(req);
 }
 
 /*
  * Called with local interrupts disabled and the q_lock held.  May not sleep.
  */
-static void *free_cmdid(struct nvme_queue *nvmeq, int cmdid,
+static void *nvme_finish_cmd(struct nvme_queue *nvmeq, int tag,
 						nvme_completion_fn *fn)
 {
+	struct nvme_cmd_info *cmd = get_cmd_from_tag(nvmeq, tag);
 	void *ctx;
-	struct nvme_cmd_info *info = nvme_cmd_info(nvmeq);
-
-	if (cmdid >= nvmeq->q_depth || !info[cmdid].fn) {
-		if (fn)
-			*fn = special_completion;
+	if (tag >= nvmeq->q_depth) {
+		*fn = special_completion;
 		return CMD_CTX_INVALID;
 	}
 	if (fn)
-		*fn = info[cmdid].fn;
-	ctx = info[cmdid].ctx;
-	info[cmdid].fn = special_completion;
-	info[cmdid].ctx = CMD_CTX_COMPLETED;
-	clear_bit(cmdid, nvmeq->cmdid_data);
-	wake_up(&nvmeq->sq_full);
+		*fn = cmd->fn;
+	ctx = cmd->ctx;
+	cmd->fn = special_completion;
+	cmd->ctx = CMD_CTX_COMPLETED;
 	return ctx;
 }
 
-static void *cancel_cmdid(struct nvme_queue *nvmeq, int cmdid,
-						nvme_completion_fn *fn)
+static void *cancel_cmd_info(struct nvme_cmd_info *cmd, nvme_completion_fn *fn)
 {
 	void *ctx;
-	struct nvme_cmd_info *info = nvme_cmd_info(nvmeq);
 	if (fn)
-		*fn = info[cmdid].fn;
-	ctx = info[cmdid].ctx;
-	info[cmdid].fn = special_completion;
-	info[cmdid].ctx = CMD_CTX_CANCELLED;
+		*fn = cmd->fn;
+	ctx = cmd->ctx;
+	cmd->fn = special_completion;
+	cmd->ctx = CMD_CTX_CANCELLED;
 	return ctx;
 }
 
-static struct nvme_queue *raw_nvmeq(struct nvme_dev *dev, int qid)
-{
-	return rcu_dereference_raw(dev->queues[qid]);
-}
-
-static struct nvme_queue *get_nvmeq(struct nvme_dev *dev) __acquires(RCU)
-{
-	unsigned queue_id = get_cpu_var(*dev->io_queue);
-	rcu_read_lock();
-	return rcu_dereference(dev->queues[queue_id]);
-}
-
-static void put_nvmeq(struct nvme_queue *nvmeq) __releases(RCU)
-{
-	rcu_read_unlock();
-	put_cpu_var(nvmeq->dev->io_queue);
-}
-
-static struct nvme_queue *lock_nvmeq(struct nvme_dev *dev, int q_idx)
-							__acquires(RCU)
-{
-	rcu_read_lock();
-	return rcu_dereference(dev->queues[q_idx]);
-}
-
-static void unlock_nvmeq(struct nvme_queue *nvmeq) __releases(RCU)
-{
-	rcu_read_unlock();
-}
-
 /**
  * nvme_submit_cmd() - Copy a command into a queue and ring the doorbell
  * @nvmeq: The queue to use
@@ -357,7 +326,6 @@ nvme_alloc_iod(unsigned nseg, unsigned nbytes, gfp_t gfp)
 		iod->length = nbytes;
 		iod->nents = 0;
 		iod->first_dma = 0ULL;
-		iod->start_time = jiffies;
 	}
 
 	return iod;
@@ -381,59 +349,26 @@ void nvme_free_iod(struct nvme_dev *dev, struct nvme_iod *iod)
 	kfree(iod);
 }
 
-static void nvme_start_io_acct(struct bio *bio)
-{
-	struct gendisk *disk = bio->bi_bdev->bd_disk;
-	const int rw = bio_data_dir(bio);
-	int cpu = part_stat_lock();
-	part_round_stats(cpu, &disk->part0);
-	part_stat_inc(cpu, &disk->part0, ios[rw]);
-	part_stat_add(cpu, &disk->part0, sectors[rw], bio_sectors(bio));
-	part_inc_in_flight(&disk->part0, rw);
-	part_stat_unlock();
-}
-
-static void nvme_end_io_acct(struct bio *bio, unsigned long start_time)
-{
-	struct gendisk *disk = bio->bi_bdev->bd_disk;
-	const int rw = bio_data_dir(bio);
-	unsigned long duration = jiffies - start_time;
-	int cpu = part_stat_lock();
-	part_stat_add(cpu, &disk->part0, ticks[rw], duration);
-	part_round_stats(cpu, &disk->part0);
-	part_dec_in_flight(&disk->part0, rw);
-	part_stat_unlock();
-}
-
-static void bio_completion(struct nvme_queue *nvmeq, void *ctx,
+static void req_completion(struct nvme_queue *nvmeq, void *ctx,
 						struct nvme_completion *cqe)
 {
 	struct nvme_iod *iod = ctx;
-	struct bio *bio = iod->private;
+	struct request *req = iod->private;
+
 	u16 status = le16_to_cpup(&cqe->status) >> 1;
 
-	if (unlikely(status)) {
-		if (!(status & NVME_SC_DNR ||
-				bio->bi_rw & REQ_FAILFAST_MASK) &&
-				(jiffies - iod->start_time) < IOD_TIMEOUT) {
-			if (!waitqueue_active(&nvmeq->sq_full))
-				add_wait_queue(&nvmeq->sq_full,
-							&nvmeq->sq_cong_wait);
-			list_add_tail(&iod->node, &nvmeq->iod_bio);
-			wake_up(&nvmeq->sq_full);
-			return;
-		}
-	}
 	if (iod->nents) {
-		dma_unmap_sg(nvmeq->q_dmadev, iod->sg, iod->nents,
-			bio_data_dir(bio) ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
-		nvme_end_io_acct(bio, iod->start_time);
+		dma_unmap_sg(&nvmeq->dev->pci_dev->dev, iod->sg, iod->nents,
+			rq_data_dir(req) ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
 	}
 	nvme_free_iod(nvmeq->dev, iod);
-	if (status)
-		bio_endio(bio, -EIO);
+
+	if (unlikely(status))
+		req->errors = -EIO;
 	else
-		bio_endio(bio, 0);
+		req->errors = 0;
+
+	blk_mq_complete_request(req);
 }
 
 /* length is in bytes.  gfp flags indicates whether we may sleep. */
@@ -515,86 +450,38 @@ int nvme_setup_prps(struct nvme_dev *dev, struct nvme_iod *iod, int total_len,
 	return total_len;
 }
 
-static int nvme_split_and_submit(struct bio *bio, struct nvme_queue *nvmeq,
-				 int len)
-{
-	struct bio *split = bio_split(bio, len >> 9, GFP_ATOMIC, NULL);
-	if (!split)
-		return -ENOMEM;
-
-	bio_chain(split, bio);
-
-	if (!waitqueue_active(&nvmeq->sq_full))
-		add_wait_queue(&nvmeq->sq_full, &nvmeq->sq_cong_wait);
-	bio_list_add(&nvmeq->sq_cong, split);
-	bio_list_add(&nvmeq->sq_cong, bio);
-	wake_up(&nvmeq->sq_full);
-
-	return 0;
-}
-
-/* NVMe scatterlists require no holes in the virtual address */
-#define BIOVEC_NOT_VIRT_MERGEABLE(vec1, vec2)	((vec2)->bv_offset || \
-			(((vec1)->bv_offset + (vec1)->bv_len) % PAGE_SIZE))
-
-static int nvme_map_bio(struct nvme_queue *nvmeq, struct nvme_iod *iod,
-		struct bio *bio, enum dma_data_direction dma_dir, int psegs)
+static int nvme_map_rq(struct nvme_queue *nvmeq, struct nvme_iod *iod,
+		struct request *req, enum dma_data_direction dma_dir,
+		int psegs)
 {
-	struct bio_vec bvec, bvprv;
-	struct bvec_iter iter;
-	struct scatterlist *sg = NULL;
-	int length = 0, nsegs = 0, split_len = bio->bi_iter.bi_size;
-	int first = 1;
-
-	if (nvmeq->dev->stripe_size)
-		split_len = nvmeq->dev->stripe_size -
-			((bio->bi_iter.bi_sector << 9) &
-			 (nvmeq->dev->stripe_size - 1));
-
 	sg_init_table(iod->sg, psegs);
-	bio_for_each_segment(bvec, bio, iter) {
-		if (!first && BIOVEC_PHYS_MERGEABLE(&bvprv, &bvec)) {
-			sg->length += bvec.bv_len;
-		} else {
-			if (!first && BIOVEC_NOT_VIRT_MERGEABLE(&bvprv, &bvec))
-				return nvme_split_and_submit(bio, nvmeq,
-							     length);
-
-			sg = sg ? sg + 1 : iod->sg;
-			sg_set_page(sg, bvec.bv_page,
-				    bvec.bv_len, bvec.bv_offset);
-			nsegs++;
-		}
+	iod->nents = blk_rq_map_sg(req->q, req, iod->sg);
 
-		if (split_len - length < bvec.bv_len)
-			return nvme_split_and_submit(bio, nvmeq, split_len);
-		length += bvec.bv_len;
-		bvprv = bvec;
-		first = 0;
-	}
-	iod->nents = nsegs;
-	sg_mark_end(sg);
-	if (dma_map_sg(nvmeq->q_dmadev, iod->sg, iod->nents, dma_dir) == 0)
+	if (!dma_map_sg(nvmeq->q_dmadev, iod->sg, iod->nents, dma_dir))
 		return -ENOMEM;
 
-	BUG_ON(length != bio->bi_iter.bi_size);
-	return length;
+	return iod->nents;
 }
 
-static int nvme_submit_discard(struct nvme_queue *nvmeq, struct nvme_ns *ns,
-		struct bio *bio, struct nvme_iod *iod, int cmdid)
+/*
+ * We reuse the small pool to allocate the 16-byte range here as it is not
+ * worth having a special pool for these or additional cases to handle freeing
+ * the iod.
+ */
+static void nvme_submit_discard(struct nvme_queue *nvmeq, struct nvme_ns *ns,
+		struct request *req, struct nvme_iod *iod)
 {
 	struct nvme_dsm_range *range =
 				(struct nvme_dsm_range *)iod_list(iod)[0];
 	struct nvme_command *cmnd = &nvmeq->sq_cmds[nvmeq->sq_tail];
 
 	range->cattr = cpu_to_le32(0);
-	range->nlb = cpu_to_le32(bio->bi_iter.bi_size >> ns->lba_shift);
-	range->slba = cpu_to_le64(nvme_block_nr(ns, bio->bi_iter.bi_sector));
+	range->nlb = cpu_to_le32(blk_rq_bytes(req) >> ns->lba_shift);
+	range->slba = cpu_to_le64(nvme_block_nr(ns, blk_rq_pos(req)));
 
 	memset(cmnd, 0, sizeof(*cmnd));
 	cmnd->dsm.opcode = nvme_cmd_dsm;
-	cmnd->dsm.command_id = cmdid;
+	cmnd->dsm.command_id = req->tag;
 	cmnd->dsm.nsid = cpu_to_le32(ns->ns_id);
 	cmnd->dsm.prp1 = cpu_to_le64(iod->first_dma);
 	cmnd->dsm.nr = 0;
@@ -603,11 +490,9 @@ static int nvme_submit_discard(struct nvme_queue *nvmeq, struct nvme_ns *ns,
 	if (++nvmeq->sq_tail == nvmeq->q_depth)
 		nvmeq->sq_tail = 0;
 	writel(nvmeq->sq_tail, nvmeq->q_db);
-
-	return 0;
 }
 
-static int nvme_submit_flush(struct nvme_queue *nvmeq, struct nvme_ns *ns,
+static void nvme_submit_flush(struct nvme_queue *nvmeq, struct nvme_ns *ns,
 								int cmdid)
 {
 	struct nvme_command *cmnd = &nvmeq->sq_cmds[nvmeq->sq_tail];
@@ -620,59 +505,49 @@ static int nvme_submit_flush(struct nvme_queue *nvmeq, struct nvme_ns *ns,
 	if (++nvmeq->sq_tail == nvmeq->q_depth)
 		nvmeq->sq_tail = 0;
 	writel(nvmeq->sq_tail, nvmeq->q_db);
-
-	return 0;
 }
 
-int nvme_submit_flush_data(struct nvme_queue *nvmeq, struct nvme_ns *ns)
+static int nvme_submit_iod(struct nvme_queue *nvmeq, struct nvme_iod *iod,
+							struct nvme_ns *ns)
 {
-	int cmdid = alloc_cmdid(nvmeq, (void *)CMD_CTX_FLUSH,
-					special_completion, NVME_IO_TIMEOUT);
-	if (unlikely(cmdid < 0))
-		return cmdid;
-
-	return nvme_submit_flush(nvmeq, ns, cmdid);
-}
-
-static int nvme_submit_iod(struct nvme_queue *nvmeq, struct nvme_iod *iod)
-{
-	struct bio *bio = iod->private;
-	struct nvme_ns *ns = bio->bi_bdev->bd_disk->private_data;
+	struct request *req = iod->private;
 	struct nvme_command *cmnd;
-	int cmdid;
-	u16 control;
-	u32 dsmgmt;
+	u16 control = 0;
+	u32 dsmgmt = 0;
 
-	cmdid = alloc_cmdid(nvmeq, iod, bio_completion, NVME_IO_TIMEOUT);
-	if (unlikely(cmdid < 0))
-		return cmdid;
+	spin_lock_irq(&nvmeq->q_lock);
+	if (nvmeq->q_suspended) {
+		spin_unlock_irq(&nvmeq->q_lock);
+		return -EBUSY;
+	}
 
-	if (bio->bi_rw & REQ_DISCARD)
-		return nvme_submit_discard(nvmeq, ns, bio, iod, cmdid);
-	if ((bio->bi_rw & REQ_FLUSH) && !iod->nents)
-		return nvme_submit_flush(nvmeq, ns, cmdid);
+	if (req->cmd_flags & REQ_DISCARD) {
+		nvme_submit_discard(nvmeq, ns, req, iod);
+		goto end_submit;
+	}
+	if (req->cmd_flags & REQ_FLUSH) {
+		nvme_submit_flush(nvmeq, ns, req->tag);
+		goto end_submit;
+	}
 
-	control = 0;
-	if (bio->bi_rw & REQ_FUA)
+	if (req->cmd_flags & REQ_FUA)
 		control |= NVME_RW_FUA;
-	if (bio->bi_rw & (REQ_FAILFAST_DEV | REQ_RAHEAD))
+	if (req->cmd_flags & (REQ_FAILFAST_DEV | REQ_RAHEAD))
 		control |= NVME_RW_LR;
 
-	dsmgmt = 0;
-	if (bio->bi_rw & REQ_RAHEAD)
+	if (req->cmd_flags & REQ_RAHEAD)
 		dsmgmt |= NVME_RW_DSM_FREQ_PREFETCH;
 
 	cmnd = &nvmeq->sq_cmds[nvmeq->sq_tail];
 	memset(cmnd, 0, sizeof(*cmnd));
 
-	cmnd->rw.opcode = bio_data_dir(bio) ? nvme_cmd_write : nvme_cmd_read;
-	cmnd->rw.command_id = cmdid;
+	cmnd->rw.opcode = (rq_data_dir(req) ? nvme_cmd_write : nvme_cmd_read);
+	cmnd->rw.command_id = req->tag;
 	cmnd->rw.nsid = cpu_to_le32(ns->ns_id);
 	cmnd->rw.prp1 = cpu_to_le64(sg_dma_address(iod->sg));
 	cmnd->rw.prp2 = cpu_to_le64(iod->first_dma);
-	cmnd->rw.slba = cpu_to_le64(nvme_block_nr(ns, bio->bi_iter.bi_sector));
-	cmnd->rw.length =
-		cpu_to_le16((bio->bi_iter.bi_size >> ns->lba_shift) - 1);
+	cmnd->rw.slba = cpu_to_le64(nvme_block_nr(ns, blk_rq_pos(req)));
+	cmnd->rw.length = cpu_to_le16((blk_rq_bytes(req) >> ns->lba_shift) - 1);
 	cmnd->rw.control = cpu_to_le16(control);
 	cmnd->rw.dsmgmt = cpu_to_le32(dsmgmt);
 
@@ -680,31 +555,29 @@ static int nvme_submit_iod(struct nvme_queue *nvmeq, struct nvme_iod *iod)
 		nvmeq->sq_tail = 0;
 	writel(nvmeq->sq_tail, nvmeq->q_db);
 
+ end_submit:
+	nvme_process_cq(nvmeq);
+	spin_unlock_irq(&nvmeq->q_lock);
 	return 0;
 }
 
-/*
- * Called with local interrupts disabled and the q_lock held.  May not sleep.
- */
-static int nvme_submit_bio_queue(struct nvme_queue *nvmeq, struct nvme_ns *ns,
-								struct bio *bio)
+static int nvme_submit_req_queue(struct nvme_queue *nvmeq, struct nvme_ns *ns,
+							  struct request *req)
 {
+	struct nvme_cmd_info *cmd = blk_mq_rq_to_pdu(req);
 	struct nvme_iod *iod;
-	int psegs = bio_phys_segments(ns->queue, bio);
-	int result;
+	enum dma_data_direction dma_dir;
+	int psegs = req->nr_phys_segments;
 
-	if ((bio->bi_rw & REQ_FLUSH) && psegs) {
-		result = nvme_submit_flush_data(nvmeq, ns);
-		if (result)
-			return result;
-	}
-
-	iod = nvme_alloc_iod(psegs, bio->bi_iter.bi_size, GFP_ATOMIC);
+	iod = nvme_alloc_iod(psegs, blk_rq_bytes(req), GFP_ATOMIC);
 	if (!iod)
-		return -ENOMEM;
+		return BLK_MQ_RQ_QUEUE_BUSY;
 
-	iod->private = bio;
-	if (bio->bi_rw & REQ_DISCARD) {
+	iod->private = req;
+
+	nvme_set_info(cmd, iod, req_completion);
+
+	if (req->cmd_flags & REQ_DISCARD) {
 		void *range;
 		/*
 		 * We reuse the small pool to allocate the 16-byte range here
@@ -714,35 +587,28 @@ static int nvme_submit_bio_queue(struct nvme_queue *nvmeq, struct nvme_ns *ns,
 		range = dma_pool_alloc(nvmeq->dev->prp_small_pool,
 						GFP_ATOMIC,
 						&iod->first_dma);
-		if (!range) {
-			result = -ENOMEM;
-			goto free_iod;
-		}
+		if (!range)
+			goto finish_cmd;
 		iod_list(iod)[0] = (__le64 *)range;
 		iod->npages = 0;
 	} else if (psegs) {
-		result = nvme_map_bio(nvmeq, iod, bio,
-			bio_data_dir(bio) ? DMA_TO_DEVICE : DMA_FROM_DEVICE,
-			psegs);
-		if (result <= 0)
-			goto free_iod;
-		if (nvme_setup_prps(nvmeq->dev, iod, result, GFP_ATOMIC) !=
-								result) {
-			result = -ENOMEM;
-			goto free_iod;
-		}
-		nvme_start_io_acct(bio);
-	}
-	if (unlikely(nvme_submit_iod(nvmeq, iod))) {
-		if (!waitqueue_active(&nvmeq->sq_full))
-			add_wait_queue(&nvmeq->sq_full, &nvmeq->sq_cong_wait);
-		list_add_tail(&iod->node, &nvmeq->iod_bio);
+		dma_dir = rq_data_dir(req) ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
+
+		if (nvme_map_rq(nvmeq, iod, req, dma_dir, psegs) <= 0)
+			goto finish_cmd;
+
+		if (blk_rq_bytes(req) != nvme_setup_prps(nvmeq->dev, iod,
+						blk_rq_bytes(req), GFP_ATOMIC))
+			goto finish_cmd;
 	}
-	return 0;
 
- free_iod:
+	if (!nvme_submit_iod(nvmeq, iod, ns))
+		return 0;
+
+ finish_cmd:
+	nvme_finish_cmd(nvmeq, req->tag, NULL);
 	nvme_free_iod(nvmeq->dev, iod);
-	return result;
+	return BLK_MQ_RQ_QUEUE_ERROR;
 }
 
 static int nvme_process_cq(struct nvme_queue *nvmeq)
@@ -763,8 +629,7 @@ static int nvme_process_cq(struct nvme_queue *nvmeq)
 			head = 0;
 			phase = !phase;
 		}
-
-		ctx = free_cmdid(nvmeq, cqe.command_id, &fn);
+		ctx = nvme_finish_cmd(nvmeq, cqe.command_id, &fn);
 		fn(nvmeq, ctx, &cqe);
 	}
 
@@ -781,34 +646,24 @@ static int nvme_process_cq(struct nvme_queue *nvmeq)
 	nvmeq->cq_head = head;
 	nvmeq->cq_phase = phase;
 
-	nvmeq->cqe_seen = 1;
 	return 1;
 }
 
-static void nvme_make_request(struct request_queue *q, struct bio *bio)
+/* Admin queue isn't initialized as a request queue. If at some point this
+ * happens anyway. Make sure to notify the user */
+static int nvme_queue_admin_request(struct blk_mq_hw_ctx *hctx,
+							struct request *req)
 {
-	struct nvme_ns *ns = q->queuedata;
-	struct nvme_queue *nvmeq = get_nvmeq(ns->dev);
-	int result = -EBUSY;
-
-	if (!nvmeq) {
-		put_nvmeq(NULL);
-		bio_endio(bio, -EIO);
-		return;
-	}
+	WARN_ON(1);
+	return BLK_MQ_RQ_QUEUE_ERROR;
+}
 
-	spin_lock_irq(&nvmeq->q_lock);
-	if (!nvmeq->q_suspended && bio_list_empty(&nvmeq->sq_cong))
-		result = nvme_submit_bio_queue(nvmeq, ns, bio);
-	if (unlikely(result)) {
-		if (!waitqueue_active(&nvmeq->sq_full))
-			add_wait_queue(&nvmeq->sq_full, &nvmeq->sq_cong_wait);
-		bio_list_add(&nvmeq->sq_cong, bio);
-	}
+static int nvme_queue_request(struct blk_mq_hw_ctx *hctx, struct request *req)
+{
+	struct nvme_ns *ns = hctx->queue->queuedata;
+	struct nvme_queue *nvmeq = hctx->driver_data;
 
-	nvme_process_cq(nvmeq);
-	spin_unlock_irq(&nvmeq->q_lock);
-	put_nvmeq(nvmeq);
+	return nvme_submit_req_queue(nvmeq, ns, req);
 }
 
 static irqreturn_t nvme_irq(int irq, void *data)
@@ -816,9 +671,7 @@ static irqreturn_t nvme_irq(int irq, void *data)
 	irqreturn_t result;
 	struct nvme_queue *nvmeq = data;
 	spin_lock(&nvmeq->q_lock);
-	nvme_process_cq(nvmeq);
-	result = nvmeq->cqe_seen ? IRQ_HANDLED : IRQ_NONE;
-	nvmeq->cqe_seen = 0;
+	result = nvme_process_cq(nvmeq) ? IRQ_HANDLED : IRQ_NONE;
 	spin_unlock(&nvmeq->q_lock);
 	return result;
 }
@@ -832,10 +685,11 @@ static irqreturn_t nvme_irq_check(int irq, void *data)
 	return IRQ_WAKE_THREAD;
 }
 
-static void nvme_abort_command(struct nvme_queue *nvmeq, int cmdid)
+static void nvme_abort_cmd_info(struct nvme_queue *nvmeq, struct nvme_cmd_info *
+								cmd_info)
 {
 	spin_lock_irq(&nvmeq->q_lock);
-	cancel_cmdid(nvmeq, cmdid, NULL);
+	cancel_cmd_info(cmd_info, NULL);
 	spin_unlock_irq(&nvmeq->q_lock);
 }
 
@@ -858,46 +712,31 @@ static void sync_completion(struct nvme_queue *nvmeq, void *ctx,
  * Returns 0 on success.  If the result is negative, it's a Linux error code;
  * if the result is positive, it's an NVM Express status code
  */
-static int nvme_submit_sync_cmd(struct nvme_dev *dev, int q_idx,
-						struct nvme_command *cmd,
+static int nvme_submit_sync_cmd(struct request *req, struct nvme_command *cmd,
 						u32 *result, unsigned timeout)
 {
-	int cmdid, ret;
+	int ret;
 	struct sync_cmd_info cmdinfo;
-	struct nvme_queue *nvmeq;
-
-	nvmeq = lock_nvmeq(dev, q_idx);
-	if (!nvmeq) {
-		unlock_nvmeq(nvmeq);
-		return -ENODEV;
-	}
+	struct nvme_cmd_info *cmd_rq = blk_mq_rq_to_pdu(req);
+	struct nvme_queue *nvmeq = cmd_rq->nvmeq;
 
 	cmdinfo.task = current;
 	cmdinfo.status = -EINTR;
 
-	cmdid = alloc_cmdid(nvmeq, &cmdinfo, sync_completion, timeout);
-	if (cmdid < 0) {
-		unlock_nvmeq(nvmeq);
-		return cmdid;
-	}
-	cmd->common.command_id = cmdid;
+	cmd->common.command_id = req->tag;
+
+	nvme_set_info(cmd_rq, &cmdinfo, sync_completion);
 
 	set_current_state(TASK_KILLABLE);
 	ret = nvme_submit_cmd(nvmeq, cmd);
 	if (ret) {
-		free_cmdid(nvmeq, cmdid, NULL);
-		unlock_nvmeq(nvmeq);
+		nvme_finish_cmd(nvmeq, req->tag, NULL);
 		set_current_state(TASK_RUNNING);
-		return ret;
 	}
-	unlock_nvmeq(nvmeq);
 	schedule_timeout(timeout);
 
 	if (cmdinfo.status == -EINTR) {
-		nvmeq = lock_nvmeq(dev, q_idx);
-		if (nvmeq)
-			nvme_abort_command(nvmeq, cmdid);
-		unlock_nvmeq(nvmeq);
+		nvme_abort_cmd_info(nvmeq, blk_mq_rq_to_pdu(req));
 		return -EINTR;
 	}
 
@@ -911,55 +750,93 @@ static int nvme_submit_async_cmd(struct nvme_queue *nvmeq,
 			struct nvme_command *cmd,
 			struct async_cmd_info *cmdinfo, unsigned timeout)
 {
-	int cmdid;
+	struct request *req;
+	struct nvme_cmd_info *cmd_rq;
 
-	cmdid = alloc_cmdid_killable(nvmeq, cmdinfo, async_completion, timeout);
-	if (cmdid < 0)
-		return cmdid;
+	req = blk_mq_alloc_request(nvmeq->hctx->queue, WRITE, GFP_KERNEL,
+					false);
+	if (!req)
+		return -ENOMEM;
+
+	req->timeout = timeout;
+	cmd_rq = blk_mq_rq_to_pdu(req);
+	cmdinfo->req = req;
+	nvme_set_info(cmd_rq, cmdinfo, async_completion);
 	cmdinfo->status = -EINTR;
-	cmd->common.command_id = cmdid;
+
+	cmd->common.command_id = req->tag;
+
 	return nvme_submit_cmd(nvmeq, cmd);
 }
 
+int __nvme_submit_admin_cmd(struct nvme_dev *dev, struct nvme_command *cmd,
+						u32 *result, unsigned timeout)
+{
+	int res;
+	struct request *req;
+
+	req = blk_mq_alloc_request(dev->admin_rq, WRITE, GFP_KERNEL, false);
+	if (!req)
+		return -ENOMEM;
+	res = nvme_submit_sync_cmd(req, cmd, result, timeout);
+	blk_put_request(req);
+	return res;
+}
+
 int nvme_submit_admin_cmd(struct nvme_dev *dev, struct nvme_command *cmd,
 								u32 *result)
 {
-	return nvme_submit_sync_cmd(dev, 0, cmd, result, ADMIN_TIMEOUT);
+	return __nvme_submit_admin_cmd(dev, cmd, result, ADMIN_TIMEOUT);
 }
 
 int nvme_submit_io_cmd(struct nvme_dev *dev, struct nvme_command *cmd,
 								u32 *result)
 {
-	return nvme_submit_sync_cmd(dev, smp_processor_id() + 1, cmd, result,
-							NVME_IO_TIMEOUT);
+	int res;
+	struct request *req;
+	struct nvme_queue *nvmeq;
+
+	nvmeq = dev->queues[(smp_processor_id() + 1) % dev->online_queues];
+	if (!nvmeq)
+		return -ENODEV;
+
+	req = blk_mq_alloc_request(nvmeq->hctx->queue, WRITE, GFP_KERNEL,
+					false);
+	if (!req)
+		return -ENOMEM;
+
+	if (nvmeq->q_suspended) {
+		res = -EBUSY;
+		goto end_sync_io;
+	}
+
+	res = nvme_submit_sync_cmd(req, cmd, result, NVME_IO_TIMEOUT);
+ end_sync_io:
+	blk_put_request(req);
+	return res;
 }
 
 static int nvme_submit_admin_cmd_async(struct nvme_dev *dev,
 		struct nvme_command *cmd, struct async_cmd_info *cmdinfo)
 {
-	return nvme_submit_async_cmd(raw_nvmeq(dev, 0), cmd, cmdinfo,
+	return nvme_submit_async_cmd(dev->queues[0], cmd, cmdinfo,
 								ADMIN_TIMEOUT);
 }
 
 static int adapter_delete_queue(struct nvme_dev *dev, u8 opcode, u16 id)
 {
-	int status;
 	struct nvme_command c;
 
 	memset(&c, 0, sizeof(c));
 	c.delete_queue.opcode = opcode;
 	c.delete_queue.qid = cpu_to_le16(id);
 
-	status = nvme_submit_admin_cmd(dev, &c, NULL);
-	if (status)
-		return -EIO;
-	return 0;
+	return nvme_submit_admin_cmd(dev, &c, NULL);
 }
 
 static int adapter_alloc_cq(struct nvme_dev *dev, u16 qid,
 						struct nvme_queue *nvmeq)
 {
-	int status;
 	struct nvme_command c;
 	int flags = NVME_QUEUE_PHYS_CONTIG | NVME_CQ_IRQ_ENABLED;
 
@@ -971,16 +848,12 @@ static int adapter_alloc_cq(struct nvme_dev *dev, u16 qid,
 	c.create_cq.cq_flags = cpu_to_le16(flags);
 	c.create_cq.irq_vector = cpu_to_le16(nvmeq->cq_vector);
 
-	status = nvme_submit_admin_cmd(dev, &c, NULL);
-	if (status)
-		return -EIO;
-	return 0;
+	return nvme_submit_admin_cmd(dev, &c, NULL);
 }
 
 static int adapter_alloc_sq(struct nvme_dev *dev, u16 qid,
 						struct nvme_queue *nvmeq)
 {
-	int status;
 	struct nvme_command c;
 	int flags = NVME_QUEUE_PHYS_CONTIG | NVME_SQ_PRIO_MEDIUM;
 
@@ -992,10 +865,7 @@ static int adapter_alloc_sq(struct nvme_dev *dev, u16 qid,
 	c.create_sq.sq_flags = cpu_to_le16(flags);
 	c.create_sq.cqid = cpu_to_le16(qid);
 
-	status = nvme_submit_admin_cmd(dev, &c, NULL);
-	if (status)
-		return -EIO;
-	return 0;
+	return nvme_submit_admin_cmd(dev, &c, NULL);
 }
 
 static int adapter_delete_cq(struct nvme_dev *dev, u16 cqid)
@@ -1051,28 +921,27 @@ int nvme_set_features(struct nvme_dev *dev, unsigned fid, unsigned dword11,
 }
 
 /**
- * nvme_abort_cmd - Attempt aborting a command
- * @cmdid: Command id of a timed out IO
- * @queue: The queue with timed out IO
+ * nvme_abort_req - Attempt aborting a rq
  *
  * Schedule controller reset if the command was already aborted once before and
  * still hasn't been returned to the driver, or if this is the admin queue.
  */
-static void nvme_abort_cmd(int cmdid, struct nvme_queue *nvmeq)
+static void nvme_abort_req(struct request *req)
 {
-	int a_cmdid;
-	struct nvme_command cmd;
+	struct nvme_cmd_info *cmd_rq = blk_mq_rq_to_pdu(req);
+	struct nvme_queue *nvmeq = cmd_rq->nvmeq;
 	struct nvme_dev *dev = nvmeq->dev;
-	struct nvme_cmd_info *info = nvme_cmd_info(nvmeq);
-	struct nvme_queue *adminq;
+	struct nvme_command cmd;
+	struct request *abort_req;
+	struct nvme_cmd_info *abort_cmd;
 
-	if (!nvmeq->qid || info[cmdid].aborted) {
+	if (!nvmeq->qid || cmd_rq->aborted) {
 		if (work_busy(&dev->reset_work))
 			return;
 		list_del_init(&dev->node);
 		dev_warn(&dev->pci_dev->dev,
-			"I/O %d QID %d timeout, reset controller\n", cmdid,
-								nvmeq->qid);
+			"I/O %d QID %d timeout, reset controller\n",
+							req->tag, nvmeq->qid);
 		dev->reset_workfn = nvme_reset_failed_dev;
 		queue_work(nvme_workq, &dev->reset_work);
 		return;
@@ -1081,83 +950,104 @@ static void nvme_abort_cmd(int cmdid, struct nvme_queue *nvmeq)
 	if (!dev->abort_limit)
 		return;
 
-	adminq = rcu_dereference(dev->queues[0]);
-	a_cmdid = alloc_cmdid(adminq, CMD_CTX_ABORT, special_completion,
-								ADMIN_TIMEOUT);
-	if (a_cmdid < 0)
-		return;
+	abort_req = blk_mq_alloc_request(dev->admin_rq, WRITE, GFP_KERNEL,
+									true);
+	abort_cmd = blk_mq_rq_to_pdu(abort_req);
+	nvme_set_info(abort_cmd, CMD_CTX_ABORT, special_completion);
 
 	memset(&cmd, 0, sizeof(cmd));
 	cmd.abort.opcode = nvme_admin_abort_cmd;
-	cmd.abort.cid = cmdid;
+	cmd.abort.cid = req->tag;
 	cmd.abort.sqid = cpu_to_le16(nvmeq->qid);
-	cmd.abort.command_id = a_cmdid;
+	cmd.abort.command_id = abort_req->tag;
 
 	--dev->abort_limit;
-	info[cmdid].aborted = 1;
-	info[cmdid].timeout = jiffies + ADMIN_TIMEOUT;
+	cmd_rq->aborted = 1;
 
-	dev_warn(nvmeq->q_dmadev, "Aborting I/O %d QID %d\n", cmdid,
+	dev_warn(nvmeq->q_dmadev, "Aborting I/O %d QID %d\n", req->tag,
 							nvmeq->qid);
-	nvme_submit_cmd(adminq, &cmd);
+	if (nvme_submit_sync_cmd(req, &cmd, NULL, ADMIN_TIMEOUT) < 0) {
+		dev_warn(nvmeq->q_dmadev, "Could not abort I/O %d QID %d",
+							req->tag, nvmeq->qid);
+	}
+	blk_put_request(req);
 }
 
-/**
- * nvme_cancel_ios - Cancel outstanding I/Os
- * @queue: The queue to cancel I/Os on
- * @timeout: True to only cancel I/Os which have timed out
- */
-static void nvme_cancel_ios(struct nvme_queue *nvmeq, bool timeout)
+static void nvme_cancel_queue_ios(void *data, unsigned long *tag_map)
 {
-	int depth = nvmeq->q_depth - 1;
-	struct nvme_cmd_info *info = nvme_cmd_info(nvmeq);
-	unsigned long now = jiffies;
-	int cmdid;
+	struct nvme_queue *nvmeq = data;
+	struct blk_mq_hw_ctx *hctx = nvmeq->hctx;
+	unsigned int tag = 0;
 
-	for_each_set_bit(cmdid, nvmeq->cmdid_data, depth) {
+	tag = 0;
+	do {
+		struct request *req;
 		void *ctx;
 		nvme_completion_fn fn;
+		struct nvme_cmd_info *cmd;
 		static struct nvme_completion cqe = {
 			.status = cpu_to_le16(NVME_SC_ABORT_REQ << 1),
 		};
+		int qdepth = nvmeq == nvmeq->dev->queues[0] ?
+					nvmeq->dev->admin_tagset.queue_depth :
+					nvmeq->dev->tagset.queue_depth;
 
-		if (timeout && !time_after(now, info[cmdid].timeout))
-			continue;
-		if (info[cmdid].ctx == CMD_CTX_CANCELLED)
-			continue;
-		if (timeout && nvmeq->dev->initialized) {
-			nvme_abort_cmd(cmdid, nvmeq);
+		/* zero'd bits are free tags */
+		tag = find_next_zero_bit(tag_map, qdepth, tag);
+		if (tag >= qdepth)
+			break;
+
+		req = blk_mq_tag_to_rq(hctx->tags, tag++);
+		cmd = blk_mq_rq_to_pdu(req);
+
+		if (cmd->ctx == CMD_CTX_CANCELLED)
 			continue;
-		}
-		dev_warn(nvmeq->q_dmadev, "Cancelling I/O %d QID %d\n", cmdid,
-								nvmeq->qid);
-		ctx = cancel_cmdid(nvmeq, cmdid, &fn);
+
+		dev_warn(nvmeq->q_dmadev, "Cancelling I/O %d QID %d\n",
+							req->tag, nvmeq->qid);
+		ctx = cancel_cmd_info(cmd, &fn);
 		fn(nvmeq, ctx, &cqe);
-	}
+
+	} while (1);
 }
 
-static void nvme_free_queue(struct rcu_head *r)
+/**
+ * nvme_cancel_ios - Cancel outstanding I/Os
+ * @queue: The queue to cancel I/Os on
+ * @timeout: True to only cancel I/Os which have timed out
+ */
+static void nvme_cancel_ios(struct nvme_queue *nvmeq)
 {
-	struct nvme_queue *nvmeq = container_of(r, struct nvme_queue, r_head);
+	struct blk_mq_hw_ctx *hctx = nvmeq->hctx;
 
-	spin_lock_irq(&nvmeq->q_lock);
-	while (bio_list_peek(&nvmeq->sq_cong)) {
-		struct bio *bio = bio_list_pop(&nvmeq->sq_cong);
-		bio_endio(bio, -EIO);
-	}
-	while (!list_empty(&nvmeq->iod_bio)) {
-		static struct nvme_completion cqe = {
-			.status = cpu_to_le16(
-				(NVME_SC_ABORT_REQ | NVME_SC_DNR) << 1),
-		};
-		struct nvme_iod *iod = list_first_entry(&nvmeq->iod_bio,
-							struct nvme_iod,
-							node);
-		list_del(&iod->node);
-		bio_completion(nvmeq, iod, &cqe);
-	}
-	spin_unlock_irq(&nvmeq->q_lock);
+	if (nvmeq->dev->initialized)
+		blk_mq_tag_busy_iter(hctx->tags, nvme_cancel_queue_ios, nvmeq);
+}
+
+static enum blk_eh_timer_return nvme_timeout(struct request *req)
+{
+	void *ctx;
+	struct nvme_cmd_info *cmd = blk_mq_rq_to_pdu(req);
+	struct nvme_queue *nvmeq = cmd->nvmeq;
+	static struct nvme_completion cqe = {
+		.status = cpu_to_le16(NVME_SC_ABORT_REQ << 1),
+	};
+	nvme_completion_fn fn;
+
+	dev_warn(nvmeq->q_dmadev, "Cancelling I/O %d QID %d\n", req->tag,
+							nvmeq->qid);
+
+	if (nvmeq->dev->initialized)
+		nvme_abort_req(req);
 
+	ctx = cancel_cmd_info(cmd, &fn);
+	fn(nvmeq, ctx, &cqe);
+
+	return BLK_EH_HANDLED;
+}
+
+static void nvme_free_queue(struct nvme_queue *nvmeq)
+{
 	dma_free_coherent(nvmeq->q_dmadev, CQ_SIZE(nvmeq->q_depth),
 				(void *)nvmeq->cqes, nvmeq->cq_dma_addr);
 	dma_free_coherent(nvmeq->q_dmadev, SQ_SIZE(nvmeq->q_depth),
@@ -1172,10 +1062,10 @@ static void nvme_free_queues(struct nvme_dev *dev, int lowest)
 	int i;
 
 	for (i = dev->queue_count - 1; i >= lowest; i--) {
-		struct nvme_queue *nvmeq = raw_nvmeq(dev, i);
-		rcu_assign_pointer(dev->queues[i], NULL);
-		call_rcu(&nvmeq->r_head, nvme_free_queue);
+		struct nvme_queue *nvmeq = dev->queues[i];
+		nvme_free_queue(nvmeq);
 		dev->queue_count--;
+		dev->queues[i] = NULL;
 	}
 }
 
@@ -1208,13 +1098,13 @@ static void nvme_clear_queue(struct nvme_queue *nvmeq)
 {
 	spin_lock_irq(&nvmeq->q_lock);
 	nvme_process_cq(nvmeq);
-	nvme_cancel_ios(nvmeq, false);
+	nvme_cancel_ios(nvmeq);
 	spin_unlock_irq(&nvmeq->q_lock);
 }
 
 static void nvme_disable_queue(struct nvme_dev *dev, int qid)
 {
-	struct nvme_queue *nvmeq = raw_nvmeq(dev, qid);
+	struct nvme_queue *nvmeq = dev->queues[qid];
 
 	if (!nvmeq)
 		return;
@@ -1234,8 +1124,7 @@ static struct nvme_queue *nvme_alloc_queue(struct nvme_dev *dev, int qid,
 							int depth, int vector)
 {
 	struct device *dmadev = &dev->pci_dev->dev;
-	unsigned extra = nvme_queue_extra(depth);
-	struct nvme_queue *nvmeq = kzalloc(sizeof(*nvmeq) + extra, GFP_KERNEL);
+	struct nvme_queue *nvmeq = kzalloc(sizeof(*nvmeq), GFP_KERNEL);
 	if (!nvmeq)
 		return NULL;
 
@@ -1260,17 +1149,13 @@ static struct nvme_queue *nvme_alloc_queue(struct nvme_dev *dev, int qid,
 	spin_lock_init(&nvmeq->q_lock);
 	nvmeq->cq_head = 0;
 	nvmeq->cq_phase = 1;
-	init_waitqueue_head(&nvmeq->sq_full);
-	init_waitqueue_entry(&nvmeq->sq_cong_wait, nvme_thread);
-	bio_list_init(&nvmeq->sq_cong);
-	INIT_LIST_HEAD(&nvmeq->iod_bio);
 	nvmeq->q_db = &dev->dbs[qid * 2 * dev->db_stride];
 	nvmeq->q_depth = depth;
 	nvmeq->cq_vector = vector;
 	nvmeq->qid = qid;
 	nvmeq->q_suspended = 1;
 	dev->queue_count++;
-	rcu_assign_pointer(dev->queues[qid], nvmeq);
+	dev->queues[qid] = nvmeq;
 
 	return nvmeq;
 
@@ -1299,15 +1184,12 @@ static int queue_request_irq(struct nvme_dev *dev, struct nvme_queue *nvmeq,
 static void nvme_init_queue(struct nvme_queue *nvmeq, u16 qid)
 {
 	struct nvme_dev *dev = nvmeq->dev;
-	unsigned extra = nvme_queue_extra(nvmeq->q_depth);
 
 	nvmeq->sq_tail = 0;
 	nvmeq->cq_head = 0;
 	nvmeq->cq_phase = 1;
 	nvmeq->q_db = &dev->dbs[qid * 2 * dev->db_stride];
-	memset(nvmeq->cmdid_data, 0, extra);
 	memset((void *)nvmeq->cqes, 0, CQ_SIZE(nvmeq->q_depth));
-	nvme_cancel_ios(nvmeq, false);
 	nvmeq->q_suspended = 0;
 	dev->online_queues++;
 }
@@ -1408,6 +1290,55 @@ static int nvme_shutdown_ctrl(struct nvme_dev *dev)
 	return 0;
 }
 
+static struct blk_mq_ops nvme_mq_admin_ops = {
+	.queue_rq	= nvme_queue_admin_request,
+	.map_queue	= blk_mq_map_queue,
+	.init_hctx	= nvme_init_admin_hctx,
+	.init_request	= nvme_init_admin_request,
+	.timeout	= nvme_timeout,
+};
+
+static struct blk_mq_ops nvme_mq_ops = {
+	.queue_rq	= nvme_queue_request,
+	.map_queue	= blk_mq_map_queue,
+	.init_hctx	= nvme_init_hctx,
+	.init_request	= nvme_init_request,
+	.timeout	= nvme_timeout,
+};
+
+static int nvme_alloc_admin_tags(struct nvme_dev *dev)
+{
+	if (!dev->admin_rq) {
+		dev->admin_tagset.ops = &nvme_mq_admin_ops;
+		dev->admin_tagset.nr_hw_queues = 1;
+		dev->admin_tagset.queue_depth = NVME_AQ_DEPTH;
+		dev->admin_tagset.reserved_tags = 1;
+		dev->admin_tagset.timeout = ADMIN_TIMEOUT;
+		dev->admin_tagset.numa_node = dev_to_node(&dev->pci_dev->dev);
+		dev->admin_tagset.cmd_size = sizeof(struct nvme_cmd_info);
+		dev->admin_tagset.driver_data = dev;
+
+		if (blk_mq_alloc_tag_set(&dev->admin_tagset))
+			return -ENOMEM;
+
+		dev->admin_rq = blk_mq_init_queue(&dev->admin_tagset);
+		if (!dev->admin_rq) {
+			memset(&dev->admin_tagset, 0,
+						sizeof(dev->admin_tagset));
+			blk_mq_free_tag_set(&dev->admin_tagset);
+			return -ENOMEM;
+		}
+	}
+
+	return 0;
+}
+
+static void nvme_free_admin_tags(struct nvme_dev *dev)
+{
+	if (dev->admin_rq)
+		blk_mq_free_tag_set(&dev->admin_tagset);
+}
+
 static int nvme_configure_admin_queue(struct nvme_dev *dev)
 {
 	int result;
@@ -1419,9 +1350,9 @@ static int nvme_configure_admin_queue(struct nvme_dev *dev)
 	if (result < 0)
 		return result;
 
-	nvmeq = raw_nvmeq(dev, 0);
+	nvmeq = dev->queues[0];
 	if (!nvmeq) {
-		nvmeq = nvme_alloc_queue(dev, 0, 64, 0);
+		nvmeq = nvme_alloc_queue(dev, 0, NVME_AQ_DEPTH, 0);
 		if (!nvmeq)
 			return -ENOMEM;
 	}
@@ -1441,16 +1372,26 @@ static int nvme_configure_admin_queue(struct nvme_dev *dev)
 
 	result = nvme_enable_ctrl(dev, cap);
 	if (result)
-		return result;
+		goto free_nvmeq;
+
+	result = nvme_alloc_admin_tags(dev);
+	if (result)
+		goto free_nvmeq;
 
 	result = queue_request_irq(dev, nvmeq, nvmeq->irqname);
 	if (result)
-		return result;
+		goto free_tags;
 
 	spin_lock_irq(&nvmeq->q_lock);
 	nvme_init_queue(nvmeq, 0);
 	spin_unlock_irq(&nvmeq->q_lock);
 	return result;
+
+ free_tags:
+	nvme_free_admin_tags(dev);
+ free_nvmeq:
+	nvme_free_queues(dev, 0);
+	return result;
 }
 
 struct nvme_iod *nvme_map_user_pages(struct nvme_dev *dev, int write,
@@ -1677,10 +1618,11 @@ static int nvme_user_admin_cmd(struct nvme_dev *dev,
 
 	timeout = cmd.timeout_ms ? msecs_to_jiffies(cmd.timeout_ms) :
 								ADMIN_TIMEOUT;
+
 	if (length != cmd.data_len)
 		status = -ENOMEM;
 	else
-		status = nvme_submit_sync_cmd(dev, 0, &c, &cmd.result, timeout);
+		status = __nvme_submit_admin_cmd(dev, &c, &cmd.result, timeout);
 
 	if (cmd.data_len) {
 		nvme_unmap_user_pages(dev, cmd.opcode & 1, iod);
@@ -1769,41 +1711,6 @@ static const struct block_device_operations nvme_fops = {
 	.getgeo		= nvme_getgeo,
 };
 
-static void nvme_resubmit_iods(struct nvme_queue *nvmeq)
-{
-	struct nvme_iod *iod, *next;
-
-	list_for_each_entry_safe(iod, next, &nvmeq->iod_bio, node) {
-		if (unlikely(nvme_submit_iod(nvmeq, iod)))
-			break;
-		list_del(&iod->node);
-		if (bio_list_empty(&nvmeq->sq_cong) &&
-						list_empty(&nvmeq->iod_bio))
-			remove_wait_queue(&nvmeq->sq_full,
-						&nvmeq->sq_cong_wait);
-	}
-}
-
-static void nvme_resubmit_bios(struct nvme_queue *nvmeq)
-{
-	while (bio_list_peek(&nvmeq->sq_cong)) {
-		struct bio *bio = bio_list_pop(&nvmeq->sq_cong);
-		struct nvme_ns *ns = bio->bi_bdev->bd_disk->private_data;
-
-		if (bio_list_empty(&nvmeq->sq_cong) &&
-						list_empty(&nvmeq->iod_bio))
-			remove_wait_queue(&nvmeq->sq_full,
-							&nvmeq->sq_cong_wait);
-		if (nvme_submit_bio_queue(nvmeq, ns, bio)) {
-			if (!waitqueue_active(&nvmeq->sq_full))
-				add_wait_queue(&nvmeq->sq_full,
-							&nvmeq->sq_cong_wait);
-			bio_list_add_head(&nvmeq->sq_cong, bio);
-			break;
-		}
-	}
-}
-
 static int nvme_kthread(void *data)
 {
 	struct nvme_dev *dev, *next;
@@ -1824,23 +1731,17 @@ static int nvme_kthread(void *data)
 				queue_work(nvme_workq, &dev->reset_work);
 				continue;
 			}
-			rcu_read_lock();
 			for (i = 0; i < dev->queue_count; i++) {
-				struct nvme_queue *nvmeq =
-						rcu_dereference(dev->queues[i]);
+				struct nvme_queue *nvmeq = dev->queues[i];
 				if (!nvmeq)
 					continue;
 				spin_lock_irq(&nvmeq->q_lock);
 				if (nvmeq->q_suspended)
 					goto unlock;
 				nvme_process_cq(nvmeq);
-				nvme_cancel_ios(nvmeq, true);
-				nvme_resubmit_bios(nvmeq);
-				nvme_resubmit_iods(nvmeq);
  unlock:
 				spin_unlock_irq(&nvmeq->q_lock);
 			}
-			rcu_read_unlock();
 		}
 		spin_unlock(&dev_list_lock);
 		schedule_timeout(round_jiffies_relative(HZ));
@@ -1863,27 +1764,29 @@ static struct nvme_ns *nvme_alloc_ns(struct nvme_dev *dev, unsigned nsid,
 {
 	struct nvme_ns *ns;
 	struct gendisk *disk;
+	int node = dev_to_node(&dev->pci_dev->dev);
 	int lbaf;
 
 	if (rt->attributes & NVME_LBART_ATTRIB_HIDE)
 		return NULL;
 
-	ns = kzalloc(sizeof(*ns), GFP_KERNEL);
+	ns = kzalloc_node(sizeof(*ns), GFP_KERNEL, node);
 	if (!ns)
 		return NULL;
-	ns->queue = blk_alloc_queue(GFP_KERNEL);
+	ns->queue = blk_mq_init_queue(&dev->tagset);
 	if (!ns->queue)
 		goto out_free_ns;
-	ns->queue->queue_flags = QUEUE_FLAG_DEFAULT;
+	queue_flag_set_unlocked(QUEUE_FLAG_DEFAULT, ns->queue);
 	queue_flag_set_unlocked(QUEUE_FLAG_NOMERGES, ns->queue);
 	queue_flag_set_unlocked(QUEUE_FLAG_NONROT, ns->queue);
-	blk_queue_make_request(ns->queue, nvme_make_request);
+	queue_flag_clear_unlocked(QUEUE_FLAG_IO_STAT, ns->queue);
 	ns->dev = dev;
 	ns->queue->queuedata = ns;
 
-	disk = alloc_disk(0);
+	disk = alloc_disk_node(0, node);
 	if (!disk)
 		goto out_free_queue;
+
 	ns->ns_id = nsid;
 	ns->disk = disk;
 	lbaf = id->flbas & 0xf;
@@ -1917,141 +1820,17 @@ static struct nvme_ns *nvme_alloc_ns(struct nvme_dev *dev, unsigned nsid,
 	return NULL;
 }
 
-static int nvme_find_closest_node(int node)
-{
-	int n, val, min_val = INT_MAX, best_node = node;
-
-	for_each_online_node(n) {
-		if (n == node)
-			continue;
-		val = node_distance(node, n);
-		if (val < min_val) {
-			min_val = val;
-			best_node = n;
-		}
-	}
-	return best_node;
-}
-
-static void nvme_set_queue_cpus(cpumask_t *qmask, struct nvme_queue *nvmeq,
-								int count)
-{
-	int cpu;
-	for_each_cpu(cpu, qmask) {
-		if (cpumask_weight(nvmeq->cpu_mask) >= count)
-			break;
-		if (!cpumask_test_and_set_cpu(cpu, nvmeq->cpu_mask))
-			*per_cpu_ptr(nvmeq->dev->io_queue, cpu) = nvmeq->qid;
-	}
-}
-
-static void nvme_add_cpus(cpumask_t *mask, const cpumask_t *unassigned_cpus,
-	const cpumask_t *new_mask, struct nvme_queue *nvmeq, int cpus_per_queue)
-{
-	int next_cpu;
-	for_each_cpu(next_cpu, new_mask) {
-		cpumask_or(mask, mask, get_cpu_mask(next_cpu));
-		cpumask_or(mask, mask, topology_thread_cpumask(next_cpu));
-		cpumask_and(mask, mask, unassigned_cpus);
-		nvme_set_queue_cpus(mask, nvmeq, cpus_per_queue);
-	}
-}
-
 static void nvme_create_io_queues(struct nvme_dev *dev)
 {
-	unsigned i, max;
+	unsigned i;
 
-	max = min(dev->max_qid, num_online_cpus());
-	for (i = dev->queue_count; i <= max; i++)
+	for (i = dev->queue_count; i <= dev->max_qid; i++)
 		if (!nvme_alloc_queue(dev, i, dev->q_depth, i - 1))
 			break;
 
-	max = min(dev->queue_count - 1, num_online_cpus());
-	for (i = dev->online_queues; i <= max; i++)
-		if (nvme_create_queue(raw_nvmeq(dev, i), i))
-			break;
-}
-
-/*
- * If there are fewer queues than online cpus, this will try to optimally
- * assign a queue to multiple cpus by grouping cpus that are "close" together:
- * thread siblings, core, socket, closest node, then whatever else is
- * available.
- */
-static void nvme_assign_io_queues(struct nvme_dev *dev)
-{
-	unsigned cpu, cpus_per_queue, queues, remainder, i;
-	cpumask_var_t unassigned_cpus;
-
-	nvme_create_io_queues(dev);
-
-	queues = min(dev->online_queues - 1, num_online_cpus());
-	if (!queues)
-		return;
-
-	cpus_per_queue = num_online_cpus() / queues;
-	remainder = queues - (num_online_cpus() - queues * cpus_per_queue);
-
-	if (!alloc_cpumask_var(&unassigned_cpus, GFP_KERNEL))
-		return;
-
-	cpumask_copy(unassigned_cpus, cpu_online_mask);
-	cpu = cpumask_first(unassigned_cpus);
-	for (i = 1; i <= queues; i++) {
-		struct nvme_queue *nvmeq = lock_nvmeq(dev, i);
-		cpumask_t mask;
-
-		cpumask_clear(nvmeq->cpu_mask);
-		if (!cpumask_weight(unassigned_cpus)) {
-			unlock_nvmeq(nvmeq);
+	for (i = dev->online_queues; i <= dev->queue_count -1; i++)
+		if (nvme_create_queue(dev->queues[i], i))
 			break;
-		}
-
-		mask = *get_cpu_mask(cpu);
-		nvme_set_queue_cpus(&mask, nvmeq, cpus_per_queue);
-		if (cpus_weight(mask) < cpus_per_queue)
-			nvme_add_cpus(&mask, unassigned_cpus,
-				topology_thread_cpumask(cpu),
-				nvmeq, cpus_per_queue);
-		if (cpus_weight(mask) < cpus_per_queue)
-			nvme_add_cpus(&mask, unassigned_cpus,
-				topology_core_cpumask(cpu),
-				nvmeq, cpus_per_queue);
-		if (cpus_weight(mask) < cpus_per_queue)
-			nvme_add_cpus(&mask, unassigned_cpus,
-				cpumask_of_node(cpu_to_node(cpu)),
-				nvmeq, cpus_per_queue);
-		if (cpus_weight(mask) < cpus_per_queue)
-			nvme_add_cpus(&mask, unassigned_cpus,
-				cpumask_of_node(
-					nvme_find_closest_node(
-						cpu_to_node(cpu))),
-				nvmeq, cpus_per_queue);
-		if (cpus_weight(mask) < cpus_per_queue)
-			nvme_add_cpus(&mask, unassigned_cpus,
-				unassigned_cpus,
-				nvmeq, cpus_per_queue);
-
-		WARN(cpumask_weight(nvmeq->cpu_mask) != cpus_per_queue,
-			"nvme%d qid:%d mis-matched queue-to-cpu assignment\n",
-			dev->instance, i);
-
-		irq_set_affinity_hint(dev->entry[nvmeq->cq_vector].vector,
-							nvmeq->cpu_mask);
-		cpumask_andnot(unassigned_cpus, unassigned_cpus,
-						nvmeq->cpu_mask);
-		cpu = cpumask_next(cpu, unassigned_cpus);
-		if (remainder && !--remainder)
-			cpus_per_queue++;
-		unlock_nvmeq(nvmeq);
-	}
-	WARN(cpumask_weight(unassigned_cpus), "nvme%d unassigned online cpus\n",
-								dev->instance);
-	i = 0;
-	cpumask_andnot(unassigned_cpus, cpu_possible_mask, cpu_online_mask);
-	for_each_cpu(cpu, unassigned_cpus)
-		*per_cpu_ptr(dev->io_queue, cpu) = (i++ % queues) + 1;
-	free_cpumask_var(unassigned_cpus);
 }
 
 static int set_queue_count(struct nvme_dev *dev, int count)
@@ -2077,22 +1856,9 @@ static size_t db_bar_size(struct nvme_dev *dev, unsigned nr_io_queues)
 	return 4096 + ((nr_io_queues + 1) * 8 * dev->db_stride);
 }
 
-static int nvme_cpu_notify(struct notifier_block *self,
-				unsigned long action, void *hcpu)
-{
-	struct nvme_dev *dev = container_of(self, struct nvme_dev, nb);
-	switch (action) {
-	case CPU_ONLINE:
-	case CPU_DEAD:
-		nvme_assign_io_queues(dev);
-		break;
-	}
-	return NOTIFY_OK;
-}
-
 static int nvme_setup_io_queues(struct nvme_dev *dev)
 {
-	struct nvme_queue *adminq = raw_nvmeq(dev, 0);
+	struct nvme_queue *adminq = dev->queues[0];
 	struct pci_dev *pdev = dev->pci_dev;
 	int result, i, vecs, nr_io_queues, size;
 
@@ -2151,12 +1917,7 @@ static int nvme_setup_io_queues(struct nvme_dev *dev)
 
 	/* Free previously allocated queues that are no longer usable */
 	nvme_free_queues(dev, nr_io_queues + 1);
-	nvme_assign_io_queues(dev);
-
-	dev->nb.notifier_call = &nvme_cpu_notify;
-	result = register_hotcpu_notifier(&dev->nb);
-	if (result)
-		goto free_queues;
+	nvme_create_io_queues(dev);
 
 	return 0;
 
@@ -2208,6 +1969,18 @@ static int nvme_dev_add(struct nvme_dev *dev)
 			(pdev->device == 0x0953) && ctrl->vs[3])
 		dev->stripe_size = 1 << (ctrl->vs[3] + shift);
 
+	dev->tagset.ops = &nvme_mq_ops;
+	dev->tagset.nr_hw_queues = dev->online_queues - 1;
+	dev->tagset.timeout = NVME_IO_TIMEOUT;
+	dev->tagset.numa_node = dev_to_node(&dev->pci_dev->dev);
+	dev->tagset.queue_depth = min_t(int, dev->q_depth, BLK_MQ_MAX_DEPTH);
+	dev->tagset.cmd_size = sizeof(struct nvme_cmd_info);
+	dev->tagset.flags = BLK_MQ_F_SHOULD_MERGE;
+	dev->tagset.driver_data = dev;
+
+	if (blk_mq_alloc_tag_set(&dev->tagset))
+		goto out;
+
 	id_ns = mem;
 	for (i = 1; i <= nn; i++) {
 		res = nvme_identify(dev, i, 0, dma_addr);
@@ -2419,7 +2192,7 @@ static void nvme_disable_io_queues(struct nvme_dev *dev)
 	atomic_set(&dq.refcount, 0);
 	dq.worker = &worker;
 	for (i = dev->queue_count - 1; i > 0; i--) {
-		struct nvme_queue *nvmeq = raw_nvmeq(dev, i);
+		struct nvme_queue *nvmeq = dev->queues[i];
 
 		if (nvme_suspend_queue(nvmeq))
 			continue;
@@ -2457,13 +2230,12 @@ static void nvme_dev_shutdown(struct nvme_dev *dev)
 	int i;
 
 	dev->initialized = 0;
-	unregister_hotcpu_notifier(&dev->nb);
 
 	nvme_dev_list_remove(dev);
 
 	if (!dev->bar || (dev->bar && readl(&dev->bar->csts) == -1)) {
 		for (i = dev->queue_count - 1; i >= 0; i--) {
-			struct nvme_queue *nvmeq = raw_nvmeq(dev, i);
+			struct nvme_queue *nvmeq = dev->queues[i];
 			nvme_suspend_queue(nvmeq);
 			nvme_clear_queue(nvmeq);
 		}
@@ -2556,7 +2328,7 @@ static void nvme_free_dev(struct kref *kref)
 	struct nvme_dev *dev = container_of(kref, struct nvme_dev, kref);
 
 	nvme_free_namespaces(dev);
-	free_percpu(dev->io_queue);
+	blk_mq_free_tag_set(&dev->tagset);
 	kfree(dev->queues);
 	kfree(dev->entry);
 	kfree(dev);
@@ -2708,23 +2480,24 @@ static void nvme_reset_workfn(struct work_struct *work)
 
 static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
-	int result = -ENOMEM;
+	int node, result = -ENOMEM;
 	struct nvme_dev *dev;
 
-	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	node = dev_to_node(&pdev->dev);
+	if (node == NUMA_NO_NODE)
+		set_dev_node(&pdev->dev, 0);
+
+	dev = kzalloc_node(sizeof(*dev), GFP_KERNEL, node);
 	if (!dev)
 		return -ENOMEM;
-	dev->entry = kcalloc(num_possible_cpus(), sizeof(*dev->entry),
-								GFP_KERNEL);
+	dev->entry = kzalloc_node(num_possible_cpus() * sizeof(*dev->entry),
+							GFP_KERNEL, node);
 	if (!dev->entry)
 		goto free;
-	dev->queues = kcalloc(num_possible_cpus() + 1, sizeof(void *),
-								GFP_KERNEL);
+	dev->queues = kzalloc_node((num_possible_cpus() + 1) * sizeof(void *),
+							GFP_KERNEL, node);
 	if (!dev->queues)
 		goto free;
-	dev->io_queue = alloc_percpu(unsigned short);
-	if (!dev->io_queue)
-		goto free;
 
 	INIT_LIST_HEAD(&dev->namespaces);
 	dev->reset_workfn = nvme_reset_failed_dev;
@@ -2775,7 +2548,6 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
  release:
 	nvme_release_instance(dev);
  free:
-	free_percpu(dev->io_queue);
 	kfree(dev->queues);
 	kfree(dev->entry);
 	kfree(dev);
@@ -2802,7 +2574,7 @@ static void nvme_remove(struct pci_dev *pdev)
 	nvme_dev_remove(dev);
 	nvme_dev_shutdown(dev);
 	nvme_free_queues(dev, 0);
-	rcu_barrier();
+	nvme_free_admin_tags(dev);
 	nvme_release_instance(dev);
 	nvme_release_prp_pools(dev);
 	kref_put(&dev->kref, nvme_free_dev);
diff --git a/include/linux/nvme.h b/include/linux/nvme.h
index 6266373..82b422d 100644
--- a/include/linux/nvme.h
+++ b/include/linux/nvme.h
@@ -19,6 +19,7 @@
 #include <linux/pci.h>
 #include <linux/miscdevice.h>
 #include <linux/kref.h>
+#include <linux/blk-mq.h>
 
 struct nvme_bar {
 	__u64			cap;	/* Controller Capabilities */
@@ -70,8 +71,10 @@ extern unsigned char io_timeout;
  */
 struct nvme_dev {
 	struct list_head node;
-	struct nvme_queue __rcu **queues;
-	unsigned short __percpu *io_queue;
+	struct nvme_queue **queues;
+	struct request_queue *admin_rq;
+	struct blk_mq_tag_set admin_tagset;
+	struct blk_mq_tag_set tagset;
 	u32 __iomem *dbs;
 	struct pci_dev *pci_dev;
 	struct dma_pool *prp_page_pool;
@@ -90,7 +93,6 @@ struct nvme_dev {
 	struct miscdevice miscdev;
 	work_func_t reset_workfn;
 	struct work_struct reset_work;
-	struct notifier_block nb;
 	char name[12];
 	char serial[20];
 	char model[40];
@@ -132,7 +134,6 @@ struct nvme_iod {
 	int offset;		/* Of PRP list */
 	int nents;		/* Used in scatterlist */
 	int length;		/* Of data, in bytes */
-	unsigned long start_time;
 	dma_addr_t first_dma;
 	struct list_head node;
 	struct scatterlist sg[0];
@@ -150,7 +151,7 @@ static inline u64 nvme_block_nr(struct nvme_ns *ns, sector_t sector)
  */
 void nvme_free_iod(struct nvme_dev *dev, struct nvme_iod *iod);
 
-int nvme_setup_prps(struct nvme_dev *, struct nvme_iod *, int , gfp_t);
+int nvme_setup_prps(struct nvme_dev *, struct nvme_iod *, int, gfp_t);
 struct nvme_iod *nvme_map_user_pages(struct nvme_dev *dev, int write,
 				unsigned long addr, unsigned length);
 void nvme_unmap_user_pages(struct nvme_dev *dev, int write,
-- 
1.9.1

Re: [PATCH v4] NVMe: basic conversion to blk-mq

[Matthew Wilcox]

On Thu, May 29, 2014 at 11:51:25PM +0200, Matias Bjørling wrote:
> @@ -816,9 +671,7 @@ static irqreturn_t nvme_irq(int irq, void *data)
>  	irqreturn_t result;
>  	struct nvme_queue *nvmeq = data;
>  	spin_lock(&nvmeq->q_lock);
> -	nvme_process_cq(nvmeq);
> -	result = nvmeq->cqe_seen ? IRQ_HANDLED : IRQ_NONE;
> -	nvmeq->cqe_seen = 0;
> +	result = nvme_process_cq(nvmeq) ? IRQ_HANDLED : IRQ_NONE;
>  	spin_unlock(&nvmeq->q_lock);
>  	return result;
>  }

Put cqe_seen back.  I already told Sam this was wrong.
http://lists.infradead.org/pipermail/linux-nvme/2014-May/000856.html

Re: [PATCH v4] NVMe: basic conversion to blk-mq

[Matthew Wilcox]

On Thu, May 29, 2014 at 11:51:25PM +0200, Matias Bjørling wrote:
> -static int nvme_map_bio(struct nvme_queue *nvmeq, struct nvme_iod *iod,
> -		struct bio *bio, enum dma_data_direction dma_dir, int psegs)
> +static int nvme_map_rq(struct nvme_queue *nvmeq, struct nvme_iod *iod,
> +		struct request *req, enum dma_data_direction dma_dir,
> +		int psegs)
>  {
> -	struct bio_vec bvec, bvprv;
> -	struct bvec_iter iter;
> -	struct scatterlist *sg = NULL;
> -	int length = 0, nsegs = 0, split_len = bio->bi_iter.bi_size;
> -	int first = 1;
> -
> -	if (nvmeq->dev->stripe_size)
> -		split_len = nvmeq->dev->stripe_size -
> -			((bio->bi_iter.bi_sector << 9) &
> -			 (nvmeq->dev->stripe_size - 1));

You take out stripe_size here, but don't appear to put it back in
anywhere else.

Re: [PATCH v4] NVMe: basic conversion to blk-mq

[Keith Busch]

[-- Attachment #1: Type: TEXT/PLAIN, Size: 607 bytes --]

On Thu, 29 May 2014, Matias Bjørling wrote:
> This converts the current NVMe driver to utilize the blk-mq layer.

I'm pretty darn sure this new nvme_remove can cause a process
with an open reference to use queues after they're freed in the
nvme_submit_sync_command path, maybe even the admin tags too.

> @@ -2802,7 +2574,7 @@ static void nvme_remove(struct pci_dev *pdev)
> 	nvme_dev_remove(dev);
> 	nvme_dev_shutdown(dev);
> 	nvme_free_queues(dev, 0);
> -	rcu_barrier();
> +	nvme_free_admin_tags(dev);
> 	nvme_release_instance(dev);
> 	nvme_release_prp_pools(dev);
> 	kref_put(&dev->kref, nvme_free_dev);

Re: [PATCH v4] NVMe: basic conversion to blk-mq

[Matthew Wilcox]

On Thu, May 29, 2014 at 11:51:25PM +0200, Matias Bjørling wrote:
> +static int nvme_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
> +			  unsigned int i)
>  {
> +	struct nvme_dev *dev = data;
> +	struct nvme_queue *nvmeq = dev->queues[(i % dev->queue_count) + 1];
> +	BUG_ON(!nvmeq);
> +	WARN_ON(nvmeq->hctx);
> +	nvmeq->hctx = hctx;
> +	hctx->driver_data = nvmeq;
> +	return 0;
> +}

You can't call this parameter 'i'.  See Documentation/CodingStyle chapter 4.

Re: [PATCH v4] NVMe: basic conversion to blk-mq

[Matias Bjorling]

On 05/30/2014 06:48 PM, Keith Busch wrote:
> On Thu, 29 May 2014, Matias Bjørling wrote:
>> This converts the current NVMe driver to utilize the blk-mq layer.
> 
> I'm pretty darn sure this new nvme_remove can cause a process
> with an open reference to use queues after they're freed in the
> nvme_submit_sync_command path, maybe even the admin tags too.
> 

You're right. I'll put a fix in v5.

>> @@ -2802,7 +2574,7 @@ static void nvme_remove(struct pci_dev *pdev)
>>     nvme_dev_remove(dev);
>>     nvme_dev_shutdown(dev);
>>     nvme_free_queues(dev, 0);
>> -    rcu_barrier();
>> +    nvme_free_admin_tags(dev);
>>     nvme_release_instance(dev);
>>     nvme_release_prp_pools(dev);
>>     kref_put(&dev->kref, nvme_free_dev);

Re: [PATCH v4] NVMe: basic conversion to blk-mq

[Jens Axboe]

On 05/30/2014 09:00 AM, Matthew Wilcox wrote:
> On Thu, May 29, 2014 at 11:51:25PM +0200, Matias Bjørling wrote:
>> -static int nvme_map_bio(struct nvme_queue *nvmeq, struct nvme_iod *iod,
>> -		struct bio *bio, enum dma_data_direction dma_dir, int psegs)
>> +static int nvme_map_rq(struct nvme_queue *nvmeq, struct nvme_iod *iod,
>> +		struct request *req, enum dma_data_direction dma_dir,
>> +		int psegs)
>>  {
>> -	struct bio_vec bvec, bvprv;
>> -	struct bvec_iter iter;
>> -	struct scatterlist *sg = NULL;
>> -	int length = 0, nsegs = 0, split_len = bio->bi_iter.bi_size;
>> -	int first = 1;
>> -
>> -	if (nvmeq->dev->stripe_size)
>> -		split_len = nvmeq->dev->stripe_size -
>> -			((bio->bi_iter.bi_sector << 9) &
>> -			 (nvmeq->dev->stripe_size - 1));
> 
> You take out stripe_size here, but don't appear to put it back in
> anywhere else.

So I've been thinking about this one. What kind of performance impact
does it have on the device in question? Because the current logic of
adding to the congested list and waking up the thread is surely not very
fast. I'm assuming you must have seen some win, which means that the
hardware is pretty poor on requests that overlap the stripe size.

Reason I ask is trying to come up with the best strategy to make this
work. My first thought was just doing partial completions. The request
is fully mapped, but only issue the first X bytes that fit within the
stripe. On completion, simply reissue. Rinse and repeat until request is
done. But this serializes the request to the hardware, which is going to
have a performance impact as well. So the better approach would be to
simple alloc more commands and fill those in, issue them all together.
If we run out of commands, simply issue the ones we do have and continue
on completion.

Another approach would be to prevent these requests to begin with, but
that would come with some runtime overhead as well.

I guess what I'm asking (in a long winded way), is how big of an issue
is this? Is this something that the device has fixed in a firmware
update (it should), or is it something we need to care deeply about?

And finally, how big is the stripe size on device in question? That
might impact the design decision.

-- 
Jens Axboe

Re: [PATCH v4] basic conversion to blk-mq

[Christoph Hellwig]

On Thu, May 29, 2014 at 11:51:24PM +0200, Matias Bj??rling wrote:
> Hi Matthew and Keith,
> 
> Thanks for the quick review.
> 
> The patch has been updated with the feedback from Keith and Jens. It's against
> Jens' 3.16/core tree. You may use the nvmemq_wip_review branch at:
> 
> https://github.com/MatiasBjorling/linux-collab nvmemq_wip_review

It seems like this includes more patches than the one you're sending
out, care to send the full series next time?

Re: [PATCH v4] NVMe: basic conversion to blk-mq

[Christoph Hellwig]

> +static int nvme_map_rq(struct nvme_queue *nvmeq, struct nvme_iod *iod,
> +		struct request *req, enum dma_data_direction dma_dir,
> +		int psegs)
>  {
>  	sg_init_table(iod->sg, psegs);
> +	iod->nents = blk_rq_map_sg(req->q, req, iod->sg);
>  
> +	if (!dma_map_sg(nvmeq->q_dmadev, iod->sg, iod->nents, dma_dir))
>  		return -ENOMEM;
>  
> +	return iod->nents;

Given how simple I'd suggest merging this into the only caller.

> +static int nvme_submit_iod(struct nvme_queue *nvmeq, struct nvme_iod *iod,
> +							struct nvme_ns *ns)
>  {
> +	struct request *req = iod->private;
>  	struct nvme_command *cmnd;
> +	u16 control = 0;
> +	u32 dsmgmt = 0;
>  
> +	spin_lock_irq(&nvmeq->q_lock);
> +	if (nvmeq->q_suspended) {
> +		spin_unlock_irq(&nvmeq->q_lock);
> +		return -EBUSY;
> +	}
>  
> +	if (req->cmd_flags & REQ_DISCARD) {
> +		nvme_submit_discard(nvmeq, ns, req, iod);
> +		goto end_submit;
> +	}
> +	if (req->cmd_flags & REQ_FLUSH) {
> +		nvme_submit_flush(nvmeq, ns, req->tag);
> +		goto end_submit;
> +	}

It would be nicer to have the locking and the the suspend check
in the caller, and then branch out to one function for each type
of request, especially as the caller already has special cases for
discard and zero-payload requests anyway.

> +static int nvme_queue_request(struct blk_mq_hw_ctx *hctx, struct request *req)
> +{

Can you call this nvme_queue_rq to match the method name?  Makes
grepping so much easier..  (ditto for the admin queue).

> +	struct nvme_ns *ns = hctx->queue->queuedata;
> +	struct nvme_queue *nvmeq = hctx->driver_data;
>  
> +	return nvme_submit_req_queue(nvmeq, ns, req);

What's the point of the serparate nvme_submit_req_queue function?

>  	spin_lock(&nvmeq->q_lock);
> -	nvme_process_cq(nvmeq);
> -	result = nvmeq->cqe_seen ? IRQ_HANDLED : IRQ_NONE;
> -	nvmeq->cqe_seen = 0;
> +	result = nvme_process_cq(nvmeq) ? IRQ_HANDLED : IRQ_NONE;

No other caller checks the nvme_process_cq return value, so it might
as well return the IRQ_ values directly.

> +static struct blk_mq_ops nvme_mq_admin_ops = {
> +	.queue_rq	= nvme_queue_admin_request,
> +	.map_queue	= blk_mq_map_queue,
> +	.init_hctx	= nvme_init_admin_hctx,
> +	.init_request	= nvme_init_admin_request,
> +	.timeout	= nvme_timeout,

Care to name these nvme_admin_<methodname> for easier grep-ability?

> +static int nvme_alloc_admin_tags(struct nvme_dev *dev)
> +{
> +	if (!dev->admin_rq) {

Why do you need the NULL check here?

> +		dev->admin_tagset.reserved_tags = 1;

What is the reserved tag for?

> +		dev->admin_rq = blk_mq_init_queue(&dev->admin_tagset);
> +		if (!dev->admin_rq) {
> +			memset(&dev->admin_tagset, 0,
> +						sizeof(dev->admin_tagset));
> +			blk_mq_free_tag_set(&dev->admin_tagset);

Why do you zero the tagset here before freeing it?

Re: [PATCH v4] basic conversion to blk-mq

[Christoph Hellwig]

There also should be patch to switch nvme to the block layer SG_IO
implementation and BLOCK_PC requests instead of it's own implemenation.

Not that I see any point at all in having all that cruft in nvme-scsi
to start with..

Re: [PATCH v4] basic conversion to blk-mq

[Matias Bjørling]

On 06/02/2014 11:42 AM, Christoph Hellwig wrote:
> On Thu, May 29, 2014 at 11:51:24PM +0200, Matias Bj??rling wrote:
>> Hi Matthew and Keith,
>>
>> Thanks for the quick review.
>>
>> The patch has been updated with the feedback from Keith and Jens. It's against
>> Jens' 3.16/core tree. You may use the nvmemq_wip_review branch at:
>>
>> https://github.com/MatiasBjorling/linux-collab nvmemq_wip_review
>
> It seems like this includes more patches than the one you're sending
> out, care to send the full series next time?
>

Yes. The nvmemq_wip_review currently holds the in-progress v5 patch. I 
make sure to split it out for the next serie and onward.

Re: [PATCH v4] NVMe: basic conversion to blk-mq

[Matias Bjørling]

On 06/02/2014 12:08 PM, Christoph Hellwig wrote:
>> +static int nvme_map_rq(struct nvme_queue *nvmeq, struct nvme_iod *iod,
>> +		struct request *req, enum dma_data_direction dma_dir,
>> +		int psegs)
>>   {
>>   	sg_init_table(iod->sg, psegs);
>> +	iod->nents = blk_rq_map_sg(req->q, req, iod->sg);
>>
>> +	if (!dma_map_sg(nvmeq->q_dmadev, iod->sg, iod->nents, dma_dir))
>>   		return -ENOMEM;
>>
>> +	return iod->nents;
>
> Given how simple I'd suggest merging this into the only caller.

Ok

>
>> +static int nvme_submit_iod(struct nvme_queue *nvmeq, struct nvme_iod *iod,
>> +							struct nvme_ns *ns)
>>   {
>> +	struct request *req = iod->private;
>>   	struct nvme_command *cmnd;
>> +	u16 control = 0;
>> +	u32 dsmgmt = 0;
>>
>> +	spin_lock_irq(&nvmeq->q_lock);
>> +	if (nvmeq->q_suspended) {
>> +		spin_unlock_irq(&nvmeq->q_lock);
>> +		return -EBUSY;
>> +	}
>>
>> +	if (req->cmd_flags & REQ_DISCARD) {
>> +		nvme_submit_discard(nvmeq, ns, req, iod);
>> +		goto end_submit;
>> +	}
>> +	if (req->cmd_flags & REQ_FLUSH) {
>> +		nvme_submit_flush(nvmeq, ns, req->tag);
>> +		goto end_submit;
>> +	}
>
> It would be nicer to have the locking and the the suspend check
> in the caller, and then branch out to one function for each type
> of request, especially as the caller already has special cases for
> discard and zero-payload requests anyway.
>

Ok, good idea.

>> +static int nvme_queue_request(struct blk_mq_hw_ctx *hctx, struct request *req)
>> +{
>
> Can you call this nvme_queue_rq to match the method name?  Makes
> grepping so much easier..  (ditto for the admin queue).
>

Yes

>> +	struct nvme_ns *ns = hctx->queue->queuedata;
>> +	struct nvme_queue *nvmeq = hctx->driver_data;
>>
>> +	return nvme_submit_req_queue(nvmeq, ns, req);
>
> What's the point of the serparate nvme_submit_req_queue function?
>

Removed

>>   	spin_lock(&nvmeq->q_lock);
>> -	nvme_process_cq(nvmeq);
>> -	result = nvmeq->cqe_seen ? IRQ_HANDLED : IRQ_NONE;
>> -	nvmeq->cqe_seen = 0;
>> +	result = nvme_process_cq(nvmeq) ? IRQ_HANDLED : IRQ_NONE;
>
> No other caller checks the nvme_process_cq return value, so it might
> as well return the IRQ_ values directly.

Ok (it's been changed as cqe_seen had been mistakenly removed.)
>
>> +static struct blk_mq_ops nvme_mq_admin_ops = {
>> +	.queue_rq	= nvme_queue_admin_request,
>> +	.map_queue	= blk_mq_map_queue,
>> +	.init_hctx	= nvme_init_admin_hctx,
>> +	.init_request	= nvme_init_admin_request,
>> +	.timeout	= nvme_timeout,
>
> Care to name these nvme_admin_<methodname> for easier grep-ability?

Yes

>
>> +static int nvme_alloc_admin_tags(struct nvme_dev *dev)
>> +{
>> +	if (!dev->admin_rq) {
>
> Why do you need the NULL check here?

the nvme_alloc_admin_tags is called both in nvme_dev_start and 
nvme_dev_resume. To make sure we don't double allocated it check if its 
already been allocated.

>
>> +		dev->admin_tagset.reserved_tags = 1;
>
> What is the reserved tag for?

It was for flush. However, this way to do it has been removed in the 
later series.

>
>> +		dev->admin_rq = blk_mq_init_queue(&dev->admin_tagset);
>> +		if (!dev->admin_rq) {
>> +			memset(&dev->admin_tagset, 0,
>> +						sizeof(dev->admin_tagset));
>> +			blk_mq_free_tag_set(&dev->admin_tagset);
>
> Why do you zero the tagset here before freeing it?
>

Removed.

Thanks!