From c0332694903a37cf8ecdc9102d5c9e09cf8643d0 Mon Sep 17 00:00:00 2001
From: Bart Van Assche <bart.vanassche@sandisk.com>
Date: Mon, 1 May 2017 08:58:49 -0700
Subject: block: Remove elevator_change()

Since commit 84253394927c ("remove the mg_disk driver") removed the
only caller of elevator_change(), also remove the elevator_change()
function itself.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Markus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
---
 include/linux/elevator.h | 1 -
 1 file changed, 1 deletion(-)

(limited to 'include/linux')

diff --git a/include/linux/elevator.h b/include/linux/elevator.h
index 3a216318ae73..d44840368ee7 100644
--- a/include/linux/elevator.h
+++ b/include/linux/elevator.h
@@ -214,7 +214,6 @@ extern ssize_t elv_iosched_store(struct request_queue *, const char *, size_t);
 
 extern int elevator_init(struct request_queue *, char *);
 extern void elevator_exit(struct request_queue *, struct elevator_queue *);
-extern int elevator_change(struct request_queue *, const char *);
 extern bool elv_bio_merge_ok(struct request *, struct bio *);
 extern struct elevator_queue *elevator_alloc(struct request_queue *,
 					struct elevator_type *);
-- 
cgit v1.2.3-71-gd317


From d6296d39e90c9075bc2fc15f1e86dac44930d4b5 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Mon, 1 May 2017 10:19:08 -0600
Subject: blk-mq: update ->init_request and ->exit_request prototypes

Remove the request_idx parameter, which can't be used safely now that we
support I/O schedulers with blk-mq.  Except for a superflous check in
mtip32xx it was unused anyway.

Also pass the tag_set instead of just the driver data - this allows drivers
to avoid some code duplication in a follow on cleanup.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
---
 block/blk-mq.c                    | 18 +++++-------------
 drivers/block/loop.c              |  5 ++---
 drivers/block/mtip32xx/mtip32xx.c | 20 ++++++--------------
 drivers/block/nbd.c               |  7 +++----
 drivers/block/rbd.c               |  5 ++---
 drivers/block/virtio_blk.c        |  7 +++----
 drivers/md/dm-rq.c                |  7 +++----
 drivers/mtd/ubi/block.c           |  7 +++----
 drivers/nvme/host/fc.c            | 20 +++++++++-----------
 drivers/nvme/host/pci.c           | 15 +++++++--------
 drivers/nvme/host/rdma.c          | 28 ++++++++++++++--------------
 drivers/nvme/target/loop.c        | 17 +++++++++--------
 drivers/scsi/scsi_lib.c           | 13 ++++++-------
 include/linux/blk-mq.h            |  4 ++--
 14 files changed, 74 insertions(+), 99 deletions(-)

(limited to 'include/linux')

diff --git a/block/blk-mq.c b/block/blk-mq.c
index bf90684a007a..b81e4a7cd7f2 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1655,8 +1655,7 @@ void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
 
 			if (!rq)
 				continue;
-			set->ops->exit_request(set->driver_data, rq,
-						hctx_idx, i);
+			set->ops->exit_request(set, rq, hctx_idx);
 			tags->static_rqs[i] = NULL;
 		}
 	}
@@ -1787,8 +1786,7 @@ int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
 
 			tags->static_rqs[i] = rq;
 			if (set->ops->init_request) {
-				if (set->ops->init_request(set->driver_data,
-						rq, hctx_idx, i,
+				if (set->ops->init_request(set, rq, hctx_idx,
 						node)) {
 					tags->static_rqs[i] = NULL;
 					goto fail;
@@ -1849,14 +1847,10 @@ static void blk_mq_exit_hctx(struct request_queue *q,
 		struct blk_mq_tag_set *set,
 		struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx)
 {
-	unsigned flush_start_tag = set->queue_depth;
-
 	blk_mq_tag_idle(hctx);
 
 	if (set->ops->exit_request)
-		set->ops->exit_request(set->driver_data,
-				       hctx->fq->flush_rq, hctx_idx,
-				       flush_start_tag + hctx_idx);
+		set->ops->exit_request(set, hctx->fq->flush_rq, hctx_idx);
 
 	blk_mq_sched_exit_hctx(q, hctx, hctx_idx);
 
@@ -1889,7 +1883,6 @@ static int blk_mq_init_hctx(struct request_queue *q,
 		struct blk_mq_hw_ctx *hctx, unsigned hctx_idx)
 {
 	int node;
-	unsigned flush_start_tag = set->queue_depth;
 
 	node = hctx->numa_node;
 	if (node == NUMA_NO_NODE)
@@ -1933,9 +1926,8 @@ static int blk_mq_init_hctx(struct request_queue *q,
 		goto sched_exit_hctx;
 
 	if (set->ops->init_request &&
-	    set->ops->init_request(set->driver_data,
-				   hctx->fq->flush_rq, hctx_idx,
-				   flush_start_tag + hctx_idx, node))
+	    set->ops->init_request(set, hctx->fq->flush_rq, hctx_idx,
+				   node))
 		goto free_fq;
 
 	if (hctx->flags & BLK_MQ_F_BLOCKING)
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 994403efee19..28d932906f24 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1697,9 +1697,8 @@ static void loop_queue_work(struct kthread_work *work)
 	loop_handle_cmd(cmd);
 }
 
-static int loop_init_request(void *data, struct request *rq,
-		unsigned int hctx_idx, unsigned int request_idx,
-		unsigned int numa_node)
+static int loop_init_request(struct blk_mq_tag_set *set, struct request *rq,
+		unsigned int hctx_idx, unsigned int numa_node)
 {
 	struct loop_cmd *cmd = blk_mq_rq_to_pdu(rq);
 
diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index 9108be601a64..96fe6500e941 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -3818,10 +3818,10 @@ static int mtip_queue_rq(struct blk_mq_hw_ctx *hctx,
 	return BLK_MQ_RQ_QUEUE_ERROR;
 }
 
-static void mtip_free_cmd(void *data, struct request *rq,
-			  unsigned int hctx_idx, unsigned int request_idx)
+static void mtip_free_cmd(struct blk_mq_tag_set *set, struct request *rq,
+			  unsigned int hctx_idx)
 {
-	struct driver_data *dd = data;
+	struct driver_data *dd = set->driver_data;
 	struct mtip_cmd *cmd = blk_mq_rq_to_pdu(rq);
 
 	if (!cmd->command)
@@ -3831,20 +3831,12 @@ static void mtip_free_cmd(void *data, struct request *rq,
 				cmd->command, cmd->command_dma);
 }
 
-static int mtip_init_cmd(void *data, struct request *rq, unsigned int hctx_idx,
-			 unsigned int request_idx, unsigned int numa_node)
+static int mtip_init_cmd(struct blk_mq_tag_set *set, struct request *rq,
+			 unsigned int hctx_idx, unsigned int numa_node)
 {
-	struct driver_data *dd = data;
+	struct driver_data *dd = set->driver_data;
 	struct mtip_cmd *cmd = blk_mq_rq_to_pdu(rq);
 
-	/*
-	 * For flush requests, request_idx starts at the end of the
-	 * tag space.  Since we don't support FLUSH/FUA, simply return
-	 * 0 as there's nothing to be done.
-	 */
-	if (request_idx >= MTIP_MAX_COMMAND_SLOTS)
-		return 0;
-
 	cmd->command = dmam_alloc_coherent(&dd->pdev->dev, CMD_DMA_ALLOC_SZ,
 			&cmd->command_dma, GFP_KERNEL);
 	if (!cmd->command)
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index ac376b9b852d..6b98ec2a3824 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -1396,12 +1396,11 @@ static void nbd_dbg_close(void)
 
 #endif
 
-static int nbd_init_request(void *data, struct request *rq,
-			    unsigned int hctx_idx, unsigned int request_idx,
-			    unsigned int numa_node)
+static int nbd_init_request(struct blk_mq_tag_set *set, struct request *rq,
+			    unsigned int hctx_idx, unsigned int numa_node)
 {
 	struct nbd_cmd *cmd = blk_mq_rq_to_pdu(rq);
-	cmd->nbd = data;
+	cmd->nbd = set->driver_data;
 	return 0;
 }
 
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 089ac4179919..3670e8dd03fe 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -4307,9 +4307,8 @@ out:
 	return ret;
 }
 
-static int rbd_init_request(void *data, struct request *rq,
-		unsigned int hctx_idx, unsigned int request_idx,
-		unsigned int numa_node)
+static int rbd_init_request(struct blk_mq_tag_set *set, struct request *rq,
+		unsigned int hctx_idx, unsigned int numa_node)
 {
 	struct work_struct *work = blk_mq_rq_to_pdu(rq);
 
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index f94614257462..94173de1efaa 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -573,11 +573,10 @@ static const struct device_attribute dev_attr_cache_type_rw =
 	__ATTR(cache_type, S_IRUGO|S_IWUSR,
 	       virtblk_cache_type_show, virtblk_cache_type_store);
 
-static int virtblk_init_request(void *data, struct request *rq,
-		unsigned int hctx_idx, unsigned int request_idx,
-		unsigned int numa_node)
+static int virtblk_init_request(struct blk_mq_tag_set *set, struct request *rq,
+		unsigned int hctx_idx, unsigned int numa_node)
 {
-	struct virtio_blk *vblk = data;
+	struct virtio_blk *vblk = set->driver_data;
 	struct virtblk_req *vbr = blk_mq_rq_to_pdu(rq);
 
 #ifdef CONFIG_VIRTIO_BLK_SCSI
diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c
index bff7e3bdb4ed..522d4fa8db64 100644
--- a/drivers/md/dm-rq.c
+++ b/drivers/md/dm-rq.c
@@ -719,11 +719,10 @@ int dm_old_init_request_queue(struct mapped_device *md, struct dm_table *t)
 	return 0;
 }
 
-static int dm_mq_init_request(void *data, struct request *rq,
-		       unsigned int hctx_idx, unsigned int request_idx,
-		       unsigned int numa_node)
+static int dm_mq_init_request(struct blk_mq_tag_set *set, struct request *rq,
+		unsigned int hctx_idx, unsigned int numa_node)
 {
-	return __dm_rq_init_rq(data, rq);
+	return __dm_rq_init_rq(set->driver_data, rq);
 }
 
 static int dm_mq_queue_rq(struct blk_mq_hw_ctx *hctx,
diff --git a/drivers/mtd/ubi/block.c b/drivers/mtd/ubi/block.c
index 51f2be8889b5..5497e65439df 100644
--- a/drivers/mtd/ubi/block.c
+++ b/drivers/mtd/ubi/block.c
@@ -334,10 +334,9 @@ static int ubiblock_queue_rq(struct blk_mq_hw_ctx *hctx,
 
 }
 
-static int ubiblock_init_request(void *data, struct request *req,
-				 unsigned int hctx_idx,
-				 unsigned int request_idx,
-				 unsigned int numa_node)
+static int ubiblock_init_request(struct blk_mq_tag_set *set,
+		struct request *req, unsigned int hctx_idx,
+		unsigned int numa_node)
 {
 	struct ubiblock_pdu *pdu = blk_mq_rq_to_pdu(req);
 
diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index 4976db56e351..70e689bf1cad 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -1172,12 +1172,12 @@ __nvme_fc_exit_request(struct nvme_fc_ctrl *ctrl,
 }
 
 static void
-nvme_fc_exit_request(void *data, struct request *rq,
-				unsigned int hctx_idx, unsigned int rq_idx)
+nvme_fc_exit_request(struct blk_mq_tag_set *set, struct request *rq,
+		unsigned int hctx_idx)
 {
 	struct nvme_fc_fcp_op *op = blk_mq_rq_to_pdu(rq);
 
-	return __nvme_fc_exit_request(data, op);
+	return __nvme_fc_exit_request(set->driver_data, op);
 }
 
 static int
@@ -1434,11 +1434,10 @@ out_on_error:
 }
 
 static int
-nvme_fc_init_request(void *data, struct request *rq,
-				unsigned int hctx_idx, unsigned int rq_idx,
-				unsigned int numa_node)
+nvme_fc_init_request(struct blk_mq_tag_set *set, struct request *rq,
+		unsigned int hctx_idx, unsigned int numa_node)
 {
-	struct nvme_fc_ctrl *ctrl = data;
+	struct nvme_fc_ctrl *ctrl = set->driver_data;
 	struct nvme_fc_fcp_op *op = blk_mq_rq_to_pdu(rq);
 	struct nvme_fc_queue *queue = &ctrl->queues[hctx_idx+1];
 
@@ -1446,11 +1445,10 @@ nvme_fc_init_request(void *data, struct request *rq,
 }
 
 static int
-nvme_fc_init_admin_request(void *data, struct request *rq,
-				unsigned int hctx_idx, unsigned int rq_idx,
-				unsigned int numa_node)
+nvme_fc_init_admin_request(struct blk_mq_tag_set *set, struct request *rq,
+		unsigned int hctx_idx, unsigned int numa_node)
 {
-	struct nvme_fc_ctrl *ctrl = data;
+	struct nvme_fc_ctrl *ctrl = set->driver_data;
 	struct nvme_fc_fcp_op *op = blk_mq_rq_to_pdu(rq);
 	struct nvme_fc_queue *queue = &ctrl->queues[0];
 
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index c8541c3dcd19..56a315bd4d96 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -356,11 +356,11 @@ static void nvme_admin_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_i
 	nvmeq->tags = NULL;
 }
 
-static int nvme_admin_init_request(void *data, struct request *req,
-				unsigned int hctx_idx, unsigned int rq_idx,
-				unsigned int numa_node)
+static int nvme_admin_init_request(struct blk_mq_tag_set *set,
+		struct request *req, unsigned int hctx_idx,
+		unsigned int numa_node)
 {
-	struct nvme_dev *dev = data;
+	struct nvme_dev *dev = set->driver_data;
 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
 	struct nvme_queue *nvmeq = dev->queues[0];
 
@@ -383,11 +383,10 @@ static int nvme_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
 	return 0;
 }
 
-static int nvme_init_request(void *data, struct request *req,
-				unsigned int hctx_idx, unsigned int rq_idx,
-				unsigned int numa_node)
+static int nvme_init_request(struct blk_mq_tag_set *set, struct request *req,
+		unsigned int hctx_idx, unsigned int numa_node)
 {
-	struct nvme_dev *dev = data;
+	struct nvme_dev *dev = set->driver_data;
 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
 	struct nvme_queue *nvmeq = dev->queues[hctx_idx + 1];
 
diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index 29cf88ac3f61..dd1c6deef82f 100644
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -315,16 +315,16 @@ static void __nvme_rdma_exit_request(struct nvme_rdma_ctrl *ctrl,
 			DMA_TO_DEVICE);
 }
 
-static void nvme_rdma_exit_request(void *data, struct request *rq,
-				unsigned int hctx_idx, unsigned int rq_idx)
+static void nvme_rdma_exit_request(struct blk_mq_tag_set *set,
+		struct request *rq, unsigned int hctx_idx)
 {
-	return __nvme_rdma_exit_request(data, rq, hctx_idx + 1);
+	return __nvme_rdma_exit_request(set->driver_data, rq, hctx_idx + 1);
 }
 
-static void nvme_rdma_exit_admin_request(void *data, struct request *rq,
-				unsigned int hctx_idx, unsigned int rq_idx)
+static void nvme_rdma_exit_admin_request(struct blk_mq_tag_set *set,
+		struct request *rq, unsigned int hctx_idx)
 {
-	return __nvme_rdma_exit_request(data, rq, 0);
+	return __nvme_rdma_exit_request(set->driver_data, rq, 0);
 }
 
 static int __nvme_rdma_init_request(struct nvme_rdma_ctrl *ctrl,
@@ -358,18 +358,18 @@ out_free_qe:
 	return -ENOMEM;
 }
 
-static int nvme_rdma_init_request(void *data, struct request *rq,
-				unsigned int hctx_idx, unsigned int rq_idx,
-				unsigned int numa_node)
+static int nvme_rdma_init_request(struct blk_mq_tag_set *set,
+		struct request *rq, unsigned int hctx_idx,
+		unsigned int numa_node)
 {
-	return __nvme_rdma_init_request(data, rq, hctx_idx + 1);
+	return __nvme_rdma_init_request(set->driver_data, rq, hctx_idx + 1);
 }
 
-static int nvme_rdma_init_admin_request(void *data, struct request *rq,
-				unsigned int hctx_idx, unsigned int rq_idx,
-				unsigned int numa_node)
+static int nvme_rdma_init_admin_request(struct blk_mq_tag_set *set,
+		struct request *rq, unsigned int hctx_idx,
+		unsigned int numa_node)
 {
-	return __nvme_rdma_init_request(data, rq, 0);
+	return __nvme_rdma_init_request(set->driver_data, rq, 0);
 }
 
 static int nvme_rdma_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
diff --git a/drivers/nvme/target/loop.c b/drivers/nvme/target/loop.c
index 304f1c87c160..feb497134aee 100644
--- a/drivers/nvme/target/loop.c
+++ b/drivers/nvme/target/loop.c
@@ -230,18 +230,19 @@ static int nvme_loop_init_iod(struct nvme_loop_ctrl *ctrl,
 	return 0;
 }
 
-static int nvme_loop_init_request(void *data, struct request *req,
-				unsigned int hctx_idx, unsigned int rq_idx,
-				unsigned int numa_node)
+static int nvme_loop_init_request(struct blk_mq_tag_set *set,
+		struct request *req, unsigned int hctx_idx,
+		unsigned int numa_node)
 {
-	return nvme_loop_init_iod(data, blk_mq_rq_to_pdu(req), hctx_idx + 1);
+	return nvme_loop_init_iod(set->driver_data, blk_mq_rq_to_pdu(req),
+			hctx_idx + 1);
 }
 
-static int nvme_loop_init_admin_request(void *data, struct request *req,
-				unsigned int hctx_idx, unsigned int rq_idx,
-				unsigned int numa_node)
+static int nvme_loop_init_admin_request(struct blk_mq_tag_set *set,
+		struct request *req, unsigned int hctx_idx,
+		unsigned int numa_node)
 {
-	return nvme_loop_init_iod(data, blk_mq_rq_to_pdu(req), 0);
+	return nvme_loop_init_iod(set->driver_data, blk_mq_rq_to_pdu(req), 0);
 }
 
 static int nvme_loop_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 1c3e87d6c48f..327b10206d63 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1999,11 +1999,10 @@ static enum blk_eh_timer_return scsi_timeout(struct request *req,
 	return scsi_times_out(req);
 }
 
-static int scsi_init_request(void *data, struct request *rq,
-		unsigned int hctx_idx, unsigned int request_idx,
-		unsigned int numa_node)
+static int scsi_init_request(struct blk_mq_tag_set *set, struct request *rq,
+		unsigned int hctx_idx, unsigned int numa_node)
 {
-	struct Scsi_Host *shost = data;
+	struct Scsi_Host *shost = set->driver_data;
 	struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
 
 	cmd->sense_buffer =
@@ -2014,10 +2013,10 @@ static int scsi_init_request(void *data, struct request *rq,
 	return 0;
 }
 
-static void scsi_exit_request(void *data, struct request *rq,
-		unsigned int hctx_idx, unsigned int request_idx)
+static void scsi_exit_request(struct blk_mq_tag_set *set, struct request *rq,
+		unsigned int hctx_idx)
 {
-	struct Scsi_Host *shost = data;
+	struct Scsi_Host *shost = set->driver_data;
 	struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
 
 	scsi_free_sense_buffer(shost, cmd->sense_buffer);
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index f3e5e1de1bdb..a104832e7ae5 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -86,9 +86,9 @@ typedef int (queue_rq_fn)(struct blk_mq_hw_ctx *, const struct blk_mq_queue_data
 typedef enum blk_eh_timer_return (timeout_fn)(struct request *, bool);
 typedef int (init_hctx_fn)(struct blk_mq_hw_ctx *, void *, unsigned int);
 typedef void (exit_hctx_fn)(struct blk_mq_hw_ctx *, unsigned int);
-typedef int (init_request_fn)(void *, struct request *, unsigned int,
+typedef int (init_request_fn)(struct blk_mq_tag_set *set, struct request *,
 		unsigned int, unsigned int);
-typedef void (exit_request_fn)(void *, struct request *, unsigned int,
+typedef void (exit_request_fn)(struct blk_mq_tag_set *set, struct request *,
 		unsigned int);
 typedef int (reinit_request_fn)(void *, struct request *);
 
-- 
cgit v1.2.3-71-gd317


From 9c1051aacde828073dbbab5e8e59c0fc802efa9a Mon Sep 17 00:00:00 2001
From: Omar Sandoval <osandov@fb.com>
Date: Thu, 4 May 2017 08:17:21 -0600
Subject: blk-mq: untangle debugfs and sysfs

Originally, I tied debugfs registration/unregistration together with
sysfs. There's no reason to do this, and it's getting in the way of
letting schedulers define their own debugfs attributes. Instead, tie the
debugfs registration to the lifetime of the structures themselves.

The saner lifetimes mean we can also get rid of the extra mq directory
and move everything one level up. I.e., nvme0n1/mq/hctx0/tags is now
just nvme0n1/hctx0/tags.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
---
 block/blk-core.c       |   9 +---
 block/blk-mq-debugfs.c | 110 ++++++++++++++++++++++++++++---------------------
 block/blk-mq-debugfs.h |  21 ++++++++--
 block/blk-mq-sysfs.c   |  11 -----
 block/blk-mq.c         |   7 ++++
 block/blk-sysfs.c      |   2 +
 include/linux/blk-mq.h |   4 ++
 include/linux/blkdev.h |   1 -
 8 files changed, 94 insertions(+), 71 deletions(-)

(limited to 'include/linux')

diff --git a/block/blk-core.c b/block/blk-core.c
index acdca6536562..c580b0138a7f 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -40,7 +40,6 @@
 
 #include "blk.h"
 #include "blk-mq.h"
-#include "blk-mq-debugfs.h"
 #include "blk-mq-sched.h"
 #include "blk-wbt.h"
 
@@ -562,13 +561,9 @@ void blk_cleanup_queue(struct request_queue *q)
 	 * prevent that q->request_fn() gets invoked after draining finished.
 	 */
 	blk_freeze_queue(q);
-	if (!q->mq_ops) {
-		spin_lock_irq(lock);
+	spin_lock_irq(lock);
+	if (!q->mq_ops)
 		__blk_drain_queue(q, true);
-	} else {
-		blk_mq_debugfs_unregister_mq(q);
-		spin_lock_irq(lock);
-	}
 	queue_flag_set(QUEUE_FLAG_DEAD, q);
 	spin_unlock_irq(lock);
 
diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index 1dc1847b5363..260cf76e0705 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -687,19 +687,46 @@ static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
 	{},
 };
 
+static bool debugfs_create_files(struct dentry *parent, void *data,
+				 const struct blk_mq_debugfs_attr *attr)
+{
+	d_inode(parent)->i_private = data;
+
+	for (; attr->name; attr++) {
+		if (!debugfs_create_file(attr->name, attr->mode, parent,
+					 (void *)attr, &blk_mq_debugfs_fops))
+			return false;
+	}
+	return true;
+}
+
 int blk_mq_debugfs_register(struct request_queue *q)
 {
+	struct blk_mq_hw_ctx *hctx;
+	int i;
+
 	if (!blk_debugfs_root)
 		return -ENOENT;
 
 	q->debugfs_dir = debugfs_create_dir(kobject_name(q->kobj.parent),
 					    blk_debugfs_root);
 	if (!q->debugfs_dir)
-		goto err;
+		return -ENOMEM;
 
-	if (blk_mq_debugfs_register_mq(q))
+	if (!debugfs_create_files(q->debugfs_dir, q,
+				  blk_mq_debugfs_queue_attrs))
 		goto err;
 
+	/*
+	 * blk_mq_init_hctx() attempted to do this already, but q->debugfs_dir
+	 * didn't exist yet (because we don't know what to name the directory
+	 * until the queue is registered to a gendisk).
+	 */
+	queue_for_each_hw_ctx(q, hctx, i) {
+		if (!hctx->debugfs_dir && blk_mq_debugfs_register_hctx(q, hctx))
+			goto err;
+	}
+
 	return 0;
 
 err:
@@ -710,32 +737,17 @@ err:
 void blk_mq_debugfs_unregister(struct request_queue *q)
 {
 	debugfs_remove_recursive(q->debugfs_dir);
-	q->mq_debugfs_dir = NULL;
 	q->debugfs_dir = NULL;
 }
 
-static bool debugfs_create_files(struct dentry *parent, void *data,
-				 const struct blk_mq_debugfs_attr *attr)
-{
-	d_inode(parent)->i_private = data;
-
-	for (; attr->name; attr++) {
-		if (!debugfs_create_file(attr->name, attr->mode, parent,
-					 (void *)attr, &blk_mq_debugfs_fops))
-			return false;
-	}
-	return true;
-}
-
-static int blk_mq_debugfs_register_ctx(struct request_queue *q,
-				       struct blk_mq_ctx *ctx,
-				       struct dentry *hctx_dir)
+static int blk_mq_debugfs_register_ctx(struct blk_mq_hw_ctx *hctx,
+				       struct blk_mq_ctx *ctx)
 {
 	struct dentry *ctx_dir;
 	char name[20];
 
 	snprintf(name, sizeof(name), "cpu%u", ctx->cpu);
-	ctx_dir = debugfs_create_dir(name, hctx_dir);
+	ctx_dir = debugfs_create_dir(name, hctx->debugfs_dir);
 	if (!ctx_dir)
 		return -ENOMEM;
 
@@ -745,59 +757,61 @@ static int blk_mq_debugfs_register_ctx(struct request_queue *q,
 	return 0;
 }
 
-static int blk_mq_debugfs_register_hctx(struct request_queue *q,
-					struct blk_mq_hw_ctx *hctx)
+int blk_mq_debugfs_register_hctx(struct request_queue *q,
+				 struct blk_mq_hw_ctx *hctx)
 {
 	struct blk_mq_ctx *ctx;
-	struct dentry *hctx_dir;
 	char name[20];
 	int i;
 
+	if (!q->debugfs_dir)
+		return -ENOENT;
+
 	snprintf(name, sizeof(name), "hctx%u", hctx->queue_num);
-	hctx_dir = debugfs_create_dir(name, q->mq_debugfs_dir);
-	if (!hctx_dir)
+	hctx->debugfs_dir = debugfs_create_dir(name, q->debugfs_dir);
+	if (!hctx->debugfs_dir)
 		return -ENOMEM;
 
-	if (!debugfs_create_files(hctx_dir, hctx, blk_mq_debugfs_hctx_attrs))
-		return -ENOMEM;
+	if (!debugfs_create_files(hctx->debugfs_dir, hctx,
+				  blk_mq_debugfs_hctx_attrs))
+		goto err;
 
 	hctx_for_each_ctx(hctx, ctx, i) {
-		if (blk_mq_debugfs_register_ctx(q, ctx, hctx_dir))
-			return -ENOMEM;
+		if (blk_mq_debugfs_register_ctx(hctx, ctx))
+			goto err;
 	}
 
 	return 0;
+
+err:
+	blk_mq_debugfs_unregister_hctx(hctx);
+	return -ENOMEM;
+}
+
+void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx)
+{
+	debugfs_remove_recursive(hctx->debugfs_dir);
+	hctx->debugfs_dir = NULL;
 }
 
-int blk_mq_debugfs_register_mq(struct request_queue *q)
+int blk_mq_debugfs_register_hctxs(struct request_queue *q)
 {
 	struct blk_mq_hw_ctx *hctx;
 	int i;
 
-	if (!q->debugfs_dir)
-		return -ENOENT;
-
-	q->mq_debugfs_dir = debugfs_create_dir("mq", q->debugfs_dir);
-	if (!q->mq_debugfs_dir)
-		goto err;
-
-	if (!debugfs_create_files(q->mq_debugfs_dir, q, blk_mq_debugfs_queue_attrs))
-		goto err;
-
 	queue_for_each_hw_ctx(q, hctx, i) {
 		if (blk_mq_debugfs_register_hctx(q, hctx))
-			goto err;
+			return -ENOMEM;
 	}
 
 	return 0;
-
-err:
-	blk_mq_debugfs_unregister_mq(q);
-	return -ENOMEM;
 }
 
-void blk_mq_debugfs_unregister_mq(struct request_queue *q)
+void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
 {
-	debugfs_remove_recursive(q->mq_debugfs_dir);
-	q->mq_debugfs_dir = NULL;
+	struct blk_mq_hw_ctx *hctx;
+	int i;
+
+	queue_for_each_hw_ctx(q, hctx, i)
+		blk_mq_debugfs_unregister_hctx(hctx);
 }
diff --git a/block/blk-mq-debugfs.h b/block/blk-mq-debugfs.h
index 00b0f71d0ae9..596e9b16d3d1 100644
--- a/block/blk-mq-debugfs.h
+++ b/block/blk-mq-debugfs.h
@@ -4,8 +4,11 @@
 #ifdef CONFIG_BLK_DEBUG_FS
 int blk_mq_debugfs_register(struct request_queue *q);
 void blk_mq_debugfs_unregister(struct request_queue *q);
-int blk_mq_debugfs_register_mq(struct request_queue *q);
-void blk_mq_debugfs_unregister_mq(struct request_queue *q);
+int blk_mq_debugfs_register_hctx(struct request_queue *q,
+				 struct blk_mq_hw_ctx *hctx);
+void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx);
+int blk_mq_debugfs_register_hctxs(struct request_queue *q);
+void blk_mq_debugfs_unregister_hctxs(struct request_queue *q);
 #else
 static inline int blk_mq_debugfs_register(struct request_queue *q)
 {
@@ -16,12 +19,22 @@ static inline void blk_mq_debugfs_unregister(struct request_queue *q)
 {
 }
 
-static inline int blk_mq_debugfs_register_mq(struct request_queue *q)
+static inline int blk_mq_debugfs_register_hctx(struct request_queue *q,
+					       struct blk_mq_hw_ctx *hctx)
 {
 	return 0;
 }
 
-static inline void blk_mq_debugfs_unregister_mq(struct request_queue *q)
+static inline void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx)
+{
+}
+
+static inline int blk_mq_debugfs_register_hctxs(struct request_queue *q)
+{
+	return 0;
+}
+
+static inline void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
 {
 }
 #endif
diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c
index 71a237a90d43..79969c3c234f 100644
--- a/block/blk-mq-sysfs.c
+++ b/block/blk-mq-sysfs.c
@@ -11,7 +11,6 @@
 
 #include <linux/blk-mq.h>
 #include "blk-mq.h"
-#include "blk-mq-debugfs.h"
 #include "blk-mq-tag.h"
 
 static void blk_mq_sysfs_release(struct kobject *kobj)
@@ -259,8 +258,6 @@ static void __blk_mq_unregister_dev(struct device *dev, struct request_queue *q)
 	queue_for_each_hw_ctx(q, hctx, i)
 		blk_mq_unregister_hctx(hctx);
 
-	blk_mq_debugfs_unregister_mq(q);
-
 	kobject_uevent(&q->mq_kobj, KOBJ_REMOVE);
 	kobject_del(&q->mq_kobj);
 	kobject_put(&dev->kobj);
@@ -319,8 +316,6 @@ int __blk_mq_register_dev(struct device *dev, struct request_queue *q)
 
 	kobject_uevent(&q->mq_kobj, KOBJ_ADD);
 
-	blk_mq_debugfs_register(q);
-
 	queue_for_each_hw_ctx(q, hctx, i) {
 		ret = blk_mq_register_hctx(hctx);
 		if (ret)
@@ -336,8 +331,6 @@ unreg:
 	while (--i >= 0)
 		blk_mq_unregister_hctx(q->queue_hw_ctx[i]);
 
-	blk_mq_debugfs_unregister_mq(q);
-
 	kobject_uevent(&q->mq_kobj, KOBJ_REMOVE);
 	kobject_del(&q->mq_kobj);
 	kobject_put(&dev->kobj);
@@ -365,8 +358,6 @@ void blk_mq_sysfs_unregister(struct request_queue *q)
 	if (!q->mq_sysfs_init_done)
 		goto unlock;
 
-	blk_mq_debugfs_unregister_mq(q);
-
 	queue_for_each_hw_ctx(q, hctx, i)
 		blk_mq_unregister_hctx(hctx);
 
@@ -383,8 +374,6 @@ int blk_mq_sysfs_register(struct request_queue *q)
 	if (!q->mq_sysfs_init_done)
 		goto unlock;
 
-	blk_mq_debugfs_register_mq(q);
-
 	queue_for_each_hw_ctx(q, hctx, i) {
 		ret = blk_mq_register_hctx(hctx);
 		if (ret)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 03a747105682..5d4ce7eb8dbf 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -31,6 +31,7 @@
 #include <linux/blk-mq.h>
 #include "blk.h"
 #include "blk-mq.h"
+#include "blk-mq-debugfs.h"
 #include "blk-mq-tag.h"
 #include "blk-stat.h"
 #include "blk-wbt.h"
@@ -1862,6 +1863,8 @@ static void blk_mq_exit_hctx(struct request_queue *q,
 		struct blk_mq_tag_set *set,
 		struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx)
 {
+	blk_mq_debugfs_unregister_hctx(hctx);
+
 	blk_mq_tag_idle(hctx);
 
 	if (set->ops->exit_request)
@@ -1948,6 +1951,8 @@ static int blk_mq_init_hctx(struct request_queue *q,
 	if (hctx->flags & BLK_MQ_F_BLOCKING)
 		init_srcu_struct(&hctx->queue_rq_srcu);
 
+	blk_mq_debugfs_register_hctx(q, hctx);
+
 	return 0;
 
  free_fq:
@@ -2385,6 +2390,7 @@ static void blk_mq_queue_reinit(struct request_queue *q,
 {
 	WARN_ON_ONCE(!atomic_read(&q->mq_freeze_depth));
 
+	blk_mq_debugfs_unregister_hctxs(q);
 	blk_mq_sysfs_unregister(q);
 
 	/*
@@ -2396,6 +2402,7 @@ static void blk_mq_queue_reinit(struct request_queue *q,
 	blk_mq_map_swqueue(q, online_mask);
 
 	blk_mq_sysfs_register(q);
+	blk_mq_debugfs_register_hctxs(q);
 }
 
 /*
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 9995355121d7..504fee940052 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -890,6 +890,8 @@ int blk_register_queue(struct gendisk *disk)
 	if (q->mq_ops)
 		__blk_mq_register_dev(dev, q);
 
+	blk_mq_debugfs_register(q);
+
 	kobject_uevent(&q->kobj, KOBJ_ADD);
 
 	wbt_enable_default(q);
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index a104832e7ae5..de8ed9aaa156 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -57,6 +57,10 @@ struct blk_mq_hw_ctx {
 	unsigned long		poll_considered;
 	unsigned long		poll_invoked;
 	unsigned long		poll_success;
+
+#ifdef CONFIG_BLK_DEBUG_FS
+	struct dentry		*debugfs_dir;
+#endif
 };
 
 struct blk_mq_tag_set {
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 83d28623645f..b49a79a29e58 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -579,7 +579,6 @@ struct request_queue {
 
 #ifdef CONFIG_BLK_DEBUG_FS
 	struct dentry		*debugfs_dir;
-	struct dentry		*mq_debugfs_dir;
 #endif
 
 	bool			mq_sysfs_init_done;
-- 
cgit v1.2.3-71-gd317


From d332ce091813d11a46144354baa72b755833392f Mon Sep 17 00:00:00 2001
From: Omar Sandoval <osandov@fb.com>
Date: Thu, 4 May 2017 08:24:40 -0600
Subject: blk-mq-debugfs: allow schedulers to register debugfs attributes

This provides the infrastructure for schedulers to expose their internal
state through debugfs. We add a list of queue attributes and a list of
hctx attributes to struct elevator_type and wire them up when switching
schedulers.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>

Add missing seq_file.h header in blk-mq-debugfs.h

Signed-off-by: Jens Axboe <axboe@fb.com>
---
 block/blk-mq-debugfs.c   | 74 ++++++++++++++++++++++++++++++++++++++++++------
 block/blk-mq-debugfs.h   | 37 ++++++++++++++++++++++++
 block/blk-mq-sched.c     | 24 ++++++++++------
 include/linux/blk-mq.h   |  1 +
 include/linux/blkdev.h   |  1 +
 include/linux/elevator.h |  7 +++++
 6 files changed, 127 insertions(+), 17 deletions(-)

(limited to 'include/linux')

diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index 260cf76e0705..a3b887109310 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -24,15 +24,6 @@
 #include "blk-mq-debugfs.h"
 #include "blk-mq-tag.h"
 
-struct blk_mq_debugfs_attr {
-	const char *name;
-	umode_t mode;
-	int (*show)(void *, struct seq_file *);
-	ssize_t (*write)(void *, const char __user *, size_t, loff_t *);
-	/* Set either .show or .seq_ops. */
-	const struct seq_operations *seq_ops;
-};
-
 static int blk_flags_show(struct seq_file *m, const unsigned long flags,
 			  const char *const *flag_name, int flag_name_count)
 {
@@ -725,6 +716,9 @@ int blk_mq_debugfs_register(struct request_queue *q)
 	queue_for_each_hw_ctx(q, hctx, i) {
 		if (!hctx->debugfs_dir && blk_mq_debugfs_register_hctx(q, hctx))
 			goto err;
+		if (q->elevator && !hctx->sched_debugfs_dir &&
+		    blk_mq_debugfs_register_sched_hctx(q, hctx))
+			goto err;
 	}
 
 	return 0;
@@ -737,6 +731,7 @@ err:
 void blk_mq_debugfs_unregister(struct request_queue *q)
 {
 	debugfs_remove_recursive(q->debugfs_dir);
+	q->sched_debugfs_dir = NULL;
 	q->debugfs_dir = NULL;
 }
 
@@ -791,6 +786,7 @@ err:
 void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx)
 {
 	debugfs_remove_recursive(hctx->debugfs_dir);
+	hctx->sched_debugfs_dir = NULL;
 	hctx->debugfs_dir = NULL;
 }
 
@@ -815,3 +811,63 @@ void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
 	queue_for_each_hw_ctx(q, hctx, i)
 		blk_mq_debugfs_unregister_hctx(hctx);
 }
+
+int blk_mq_debugfs_register_sched(struct request_queue *q)
+{
+	struct elevator_type *e = q->elevator->type;
+
+	if (!q->debugfs_dir)
+		return -ENOENT;
+
+	if (!e->queue_debugfs_attrs)
+		return 0;
+
+	q->sched_debugfs_dir = debugfs_create_dir("sched", q->debugfs_dir);
+	if (!q->sched_debugfs_dir)
+		return -ENOMEM;
+
+	if (!debugfs_create_files(q->sched_debugfs_dir, q,
+				  e->queue_debugfs_attrs))
+		goto err;
+
+	return 0;
+
+err:
+	blk_mq_debugfs_unregister_sched(q);
+	return -ENOMEM;
+}
+
+void blk_mq_debugfs_unregister_sched(struct request_queue *q)
+{
+	debugfs_remove_recursive(q->sched_debugfs_dir);
+	q->sched_debugfs_dir = NULL;
+}
+
+int blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
+				       struct blk_mq_hw_ctx *hctx)
+{
+	struct elevator_type *e = q->elevator->type;
+
+	if (!hctx->debugfs_dir)
+		return -ENOENT;
+
+	if (!e->hctx_debugfs_attrs)
+		return 0;
+
+	hctx->sched_debugfs_dir = debugfs_create_dir("sched",
+						     hctx->debugfs_dir);
+	if (!hctx->sched_debugfs_dir)
+		return -ENOMEM;
+
+	if (!debugfs_create_files(hctx->sched_debugfs_dir, hctx,
+				  e->hctx_debugfs_attrs))
+		return -ENOMEM;
+
+	return 0;
+}
+
+void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)
+{
+	debugfs_remove_recursive(hctx->sched_debugfs_dir);
+	hctx->sched_debugfs_dir = NULL;
+}
diff --git a/block/blk-mq-debugfs.h b/block/blk-mq-debugfs.h
index 596e9b16d3d1..a5ac21c81ea3 100644
--- a/block/blk-mq-debugfs.h
+++ b/block/blk-mq-debugfs.h
@@ -2,6 +2,18 @@
 #define INT_BLK_MQ_DEBUGFS_H
 
 #ifdef CONFIG_BLK_DEBUG_FS
+
+#include <linux/seq_file.h>
+
+struct blk_mq_debugfs_attr {
+	const char *name;
+	umode_t mode;
+	int (*show)(void *, struct seq_file *);
+	ssize_t (*write)(void *, const char __user *, size_t, loff_t *);
+	/* Set either .show or .seq_ops. */
+	const struct seq_operations *seq_ops;
+};
+
 int blk_mq_debugfs_register(struct request_queue *q);
 void blk_mq_debugfs_unregister(struct request_queue *q);
 int blk_mq_debugfs_register_hctx(struct request_queue *q,
@@ -9,6 +21,12 @@ int blk_mq_debugfs_register_hctx(struct request_queue *q,
 void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx);
 int blk_mq_debugfs_register_hctxs(struct request_queue *q);
 void blk_mq_debugfs_unregister_hctxs(struct request_queue *q);
+
+int blk_mq_debugfs_register_sched(struct request_queue *q);
+void blk_mq_debugfs_unregister_sched(struct request_queue *q);
+int blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
+				       struct blk_mq_hw_ctx *hctx);
+void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx);
 #else
 static inline int blk_mq_debugfs_register(struct request_queue *q)
 {
@@ -37,6 +55,25 @@ static inline int blk_mq_debugfs_register_hctxs(struct request_queue *q)
 static inline void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
 {
 }
+
+static inline int blk_mq_debugfs_register_sched(struct request_queue *q)
+{
+	return 0;
+}
+
+static inline void blk_mq_debugfs_unregister_sched(struct request_queue *q)
+{
+}
+
+static inline int blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
+						     struct blk_mq_hw_ctx *hctx)
+{
+	return 0;
+}
+
+static inline void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)
+{
+}
 #endif
 
 #endif
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index e79e9f18d7c2..1f5b692526ae 100644
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c
@@ -11,6 +11,7 @@
 
 #include "blk.h"
 #include "blk-mq.h"
+#include "blk-mq-debugfs.h"
 #include "blk-mq-sched.h"
 #include "blk-mq-tag.h"
 #include "blk-wbt.h"
@@ -472,6 +473,8 @@ int blk_mq_sched_init_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx,
 		}
 	}
 
+	blk_mq_debugfs_register_sched_hctx(q, hctx);
+
 	return 0;
 }
 
@@ -483,6 +486,8 @@ void blk_mq_sched_exit_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx,
 	if (!e)
 		return;
 
+	blk_mq_debugfs_unregister_sched_hctx(hctx);
+
 	if (e->type->ops.mq.exit_hctx && hctx->sched_data) {
 		e->type->ops.mq.exit_hctx(hctx, hctx_idx);
 		hctx->sched_data = NULL;
@@ -519,8 +524,10 @@ int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e)
 	if (ret)
 		goto err;
 
-	if (e->ops.mq.init_hctx) {
-		queue_for_each_hw_ctx(q, hctx, i) {
+	blk_mq_debugfs_register_sched(q);
+
+	queue_for_each_hw_ctx(q, hctx, i) {
+		if (e->ops.mq.init_hctx) {
 			ret = e->ops.mq.init_hctx(hctx, i);
 			if (ret) {
 				eq = q->elevator;
@@ -529,6 +536,7 @@ int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e)
 				return ret;
 			}
 		}
+		blk_mq_debugfs_register_sched_hctx(q, hctx);
 	}
 
 	return 0;
@@ -544,14 +552,14 @@ void blk_mq_exit_sched(struct request_queue *q, struct elevator_queue *e)
 	struct blk_mq_hw_ctx *hctx;
 	unsigned int i;
 
-	if (e->type->ops.mq.exit_hctx) {
-		queue_for_each_hw_ctx(q, hctx, i) {
-			if (hctx->sched_data) {
-				e->type->ops.mq.exit_hctx(hctx, i);
-				hctx->sched_data = NULL;
-			}
+	queue_for_each_hw_ctx(q, hctx, i) {
+		blk_mq_debugfs_unregister_sched_hctx(hctx);
+		if (e->type->ops.mq.exit_hctx && hctx->sched_data) {
+			e->type->ops.mq.exit_hctx(hctx, i);
+			hctx->sched_data = NULL;
 		}
 	}
+	blk_mq_debugfs_unregister_sched(q);
 	if (e->type->ops.mq.exit_sched)
 		e->type->ops.mq.exit_sched(e);
 	blk_mq_sched_tags_teardown(q);
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index de8ed9aaa156..c47aa248c640 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -60,6 +60,7 @@ struct blk_mq_hw_ctx {
 
 #ifdef CONFIG_BLK_DEBUG_FS
 	struct dentry		*debugfs_dir;
+	struct dentry		*sched_debugfs_dir;
 #endif
 };
 
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index b49a79a29e58..80ae958717a1 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -579,6 +579,7 @@ struct request_queue {
 
 #ifdef CONFIG_BLK_DEBUG_FS
 	struct dentry		*debugfs_dir;
+	struct dentry		*sched_debugfs_dir;
 #endif
 
 	bool			mq_sysfs_init_done;
diff --git a/include/linux/elevator.h b/include/linux/elevator.h
index d44840368ee7..9ec5e22846e0 100644
--- a/include/linux/elevator.h
+++ b/include/linux/elevator.h
@@ -8,6 +8,9 @@
 
 struct io_cq;
 struct elevator_type;
+#ifdef CONFIG_BLK_DEBUG_FS
+struct blk_mq_debugfs_attr;
+#endif
 
 /*
  * Return values from elevator merger
@@ -144,6 +147,10 @@ struct elevator_type
 	char elevator_name[ELV_NAME_MAX];
 	struct module *elevator_owner;
 	bool uses_mq;
+#ifdef CONFIG_BLK_DEBUG_FS
+	const struct blk_mq_debugfs_attr *queue_debugfs_attrs;
+	const struct blk_mq_debugfs_attr *hctx_debugfs_attrs;
+#endif
 
 	/* managed by elevator core */
 	char icq_cache_name[ELV_NAME_MAX + 5];	/* elvname + "_io_cq" */
-- 
cgit v1.2.3-71-gd317