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Commit b0b4e09c authored by Matias Bjørling's avatar Matias Bjørling Committed by Jens Axboe
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lightnvm: control life of nvm_dev in driver 



LightNVM compatible device drivers does not have a method to expose
LightNVM specific sysfs entries.

To enable LightNVM sysfs entries to be exposed, lightnvm device
drivers require a struct device to attach it to. To allow both the
actual device driver and lightnvm sysfs entries to coexist, the device
driver tracks the lifetime of the nvm_dev structure.

This patch refactors NVMe and null_blk to handle the lifetime of struct
nvm_dev, which eliminates the need for struct gendisk when a lightnvm
compatible device is provided.

Signed-off-by: default avatarMatias Bjørling <m@bjorling.me>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent b21d5b30

drivers/block/null_blk.c

+20 −2
Original line number Diff line number Diff line
@@ -34,6 +34,7 @@ struct nullb { 
	unsigned int index;

	struct request_queue *q;

	struct gendisk *disk;

	struct nvm_dev *ndev;

	struct blk_mq_tag_set tag_set;

	struct hrtimer timer;

	unsigned int queue_depth;
@@ -550,12 +551,29 @@ static struct nvm_dev_ops null_lnvm_dev_ops = { 


static int null_nvm_register(struct nullb *nullb)

{

	return nvm_register(nullb->q, nullb->disk_name, &null_lnvm_dev_ops);

	struct nvm_dev *dev;

	int rv;



	dev = nvm_alloc_dev(0);

	if (!dev)

		return -ENOMEM;



	dev->q = nullb->q;

	memcpy(dev->name, nullb->disk_name, DISK_NAME_LEN);

	dev->ops = &null_lnvm_dev_ops;



	rv = nvm_register(dev);

	if (rv) {

		kfree(dev);

		return rv;

	}

	nullb->ndev = dev;

	return 0;

}



static void null_nvm_unregister(struct nullb *nullb)

{

	nvm_unregister(nullb->disk_name);

	nvm_unregister(nullb->ndev);

}

#else

static int null_nvm_register(struct nullb *nullb)

drivers/lightnvm/core.c

+8 −27
Original line number Diff line number Diff line
@@ -660,22 +660,15 @@ static void nvm_exit(struct nvm_dev *dev) 
	pr_info("nvm: successfully unloaded\n");

}



int nvm_register(struct request_queue *q, char *disk_name,

							struct nvm_dev_ops *ops)

struct nvm_dev *nvm_alloc_dev(int node)

{

	struct nvm_dev *dev;

	int ret;



	if (!ops->identity)

		return -EINVAL;



	dev = kzalloc(sizeof(struct nvm_dev), GFP_KERNEL);

	if (!dev)

		return -ENOMEM;

	return kzalloc_node(sizeof(struct nvm_dev), GFP_KERNEL, node);

}

EXPORT_SYMBOL(nvm_alloc_dev);



	dev->q = q;

	dev->ops = ops;

	strncpy(dev->name, disk_name, DISK_NAME_LEN);

int nvm_register(struct nvm_dev *dev)

{

	int ret;



	ret = nvm_init(dev);

	if (ret)
@@ -714,29 +707,17 @@ int nvm_register(struct request_queue *q, char *disk_name, 
	return 0;

err_init:

	kfree(dev->lun_map);

	kfree(dev);

	return ret;

}

EXPORT_SYMBOL(nvm_register);



void nvm_unregister(char *disk_name)

void nvm_unregister(struct nvm_dev *dev)

{

	struct nvm_dev *dev;



	down_write(&nvm_lock);

	dev = nvm_find_nvm_dev(disk_name);

	if (!dev) {

		pr_err("nvm: could not find device %s to unregister\n",

								disk_name);

		up_write(&nvm_lock);

		return;

	}



	list_del(&dev->devices);

	up_write(&nvm_lock);



	nvm_exit(dev);

	kfree(dev);

}

EXPORT_SYMBOL(nvm_unregister);

drivers/nvme/host/core.c

+15 −21
Original line number Diff line number Diff line
@@ -156,12 +156,14 @@ static void nvme_free_ns(struct kref *kref) 
{

	struct nvme_ns *ns = container_of(kref, struct nvme_ns, kref);



	if (ns->type == NVME_NS_LIGHTNVM)

		nvme_nvm_unregister(ns->queue, ns->disk->disk_name);

	if (ns->ndev)

		nvme_nvm_unregister(ns);



	if (ns->disk) {

		spin_lock(&dev_list_lock);

		ns->disk->private_data = NULL;

		spin_unlock(&dev_list_lock);

	}



	put_disk(ns->disk);

	ida_simple_remove(&ns->ctrl->ns_ida, ns->instance);
@@ -891,8 +893,7 @@ static void nvme_config_discard(struct nvme_ns *ns) 
static int nvme_revalidate_ns(struct nvme_ns *ns, struct nvme_id_ns **id)

{

	if (nvme_identify_ns(ns->ctrl, ns->ns_id, id)) {

		dev_warn(disk_to_dev(ns->disk), "%s: Identify failure\n",

				__func__);

		dev_warn(ns->ctrl->dev, "%s: Identify failure\n", __func__);

		return -ENODEV;

	}
@@ -1683,18 +1684,11 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid) 
		goto out_free_queue;



	if (nvme_nvm_ns_supported(ns, id)) {

		if (nvme_nvm_register(ns->queue, disk_name)) {

			dev_warn(ctrl->dev,

				"%s: LightNVM init failure\n", __func__);

		if (nvme_nvm_register(ns, disk_name, node)) {

			dev_warn(ctrl->dev, "%s: LightNVM init failure\n",

								__func__);

			goto out_free_id;

		}



		disk = alloc_disk_node(0, node);

		if (!disk)

			goto out_free_id;

		memcpy(disk->disk_name, disk_name, DISK_NAME_LEN);

		ns->disk = disk;

		ns->type = NVME_NS_LIGHTNVM;

	} else {

		disk = alloc_disk_node(0, node);

		if (!disk)
@@ -1718,7 +1712,7 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid) 


	kfree(id);



	if (ns->type == NVME_NS_LIGHTNVM)

	if (ns->ndev)

		return;



	device_add_disk(ctrl->device, ns->disk);
@@ -1742,7 +1736,7 @@ static void nvme_ns_remove(struct nvme_ns *ns) 
	if (test_and_set_bit(NVME_NS_REMOVING, &ns->flags))

		return;



	if (ns->disk->flags & GENHD_FL_UP) {

	if (ns->disk && ns->disk->flags & GENHD_FL_UP) {

		if (blk_get_integrity(ns->disk))

			blk_integrity_unregister(ns->disk);

		sysfs_remove_group(&disk_to_dev(ns->disk)->kobj,
@@ -1765,7 +1759,7 @@ static void nvme_validate_ns(struct nvme_ctrl *ctrl, unsigned nsid) 


	ns = nvme_find_get_ns(ctrl, nsid);

	if (ns) {

		if (revalidate_disk(ns->disk))

		if (ns->disk && revalidate_disk(ns->disk))

			nvme_ns_remove(ns);

		nvme_put_ns(ns);

	} else
@@ -2070,7 +2064,7 @@ void nvme_kill_queues(struct nvme_ctrl *ctrl) 
		 * Revalidating a dead namespace sets capacity to 0. This will

		 * end buffered writers dirtying pages that can't be synced.

		 */

		if (!test_and_set_bit(NVME_NS_DEAD, &ns->flags))

		if (ns->disk && !test_and_set_bit(NVME_NS_DEAD, &ns->flags))

			revalidate_disk(ns->disk);



		blk_set_queue_dying(ns->queue);

drivers/nvme/host/lightnvm.c

+24 −7
Original line number Diff line number Diff line
@@ -474,9 +474,8 @@ static inline void nvme_nvm_rqtocmd(struct request *rq, struct nvm_rq *rqd, 
	c->ph_rw.length = cpu_to_le16(rqd->nr_ppas - 1);



	if (rqd->opcode == NVM_OP_HBWRITE || rqd->opcode == NVM_OP_HBREAD)

		/* momentarily hardcode the shift configuration. lba_shift from

		 * nvm_dev will be available in a follow-up patch */

		c->hb_rw.slba = cpu_to_le64(rqd->bio->bi_iter.bi_sector >> 3);

		c->hb_rw.slba = cpu_to_le64(nvme_block_nr(ns,

					rqd->bio->bi_iter.bi_sector));

}



static void nvme_nvm_end_io(struct request *rq, int error)
@@ -593,14 +592,32 @@ static struct nvm_dev_ops nvme_nvm_dev_ops = { 
	.max_phys_sect		= 64,

};



int nvme_nvm_register(struct request_queue *q, char *disk_name)

int nvme_nvm_register(struct nvme_ns *ns, char *disk_name, int node)

{

	return nvm_register(q, disk_name, &nvme_nvm_dev_ops);

	struct request_queue *q = ns->queue;

	struct nvm_dev *dev;

	int ret;



	dev = nvm_alloc_dev(node);

	if (!dev)

		return -ENOMEM;



	dev->q = q;

	memcpy(dev->name, disk_name, DISK_NAME_LEN);

	dev->ops = &nvme_nvm_dev_ops;

	ns->ndev = dev;



	ret = nvm_register(dev);



	ns->lba_shift = ilog2(dev->sec_size) - 9;



	return ret;

}



void nvme_nvm_unregister(struct request_queue *q, char *disk_name)

void nvme_nvm_unregister(struct nvme_ns *ns)

{

	nvm_unregister(disk_name);

	nvm_unregister(ns->ndev);

	kfree(ns->ndev);

}



/* move to shared place when used in multiple places. */

drivers/nvme/host/nvme.h

+7 −5
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 
#include <linux/pci.h>

#include <linux/kref.h>

#include <linux/blk-mq.h>

#include <linux/lightnvm.h>



enum {

	/*
@@ -154,6 +155,7 @@ struct nvme_ns { 
	struct nvme_ctrl *ctrl;

	struct request_queue *queue;

	struct gendisk *disk;

	struct nvm_dev *ndev;

	struct kref kref;

	int instance;
@@ -165,7 +167,6 @@ struct nvme_ns { 
	u16 ms;

	bool ext;

	u8 pi_type;

	int type;

	unsigned long flags;



#define NVME_NS_REMOVING 0
@@ -307,15 +308,16 @@ int nvme_sg_get_version_num(int __user *ip); 


#ifdef CONFIG_NVM

int nvme_nvm_ns_supported(struct nvme_ns *ns, struct nvme_id_ns *id);

int nvme_nvm_register(struct request_queue *q, char *disk_name);

void nvme_nvm_unregister(struct request_queue *q, char *disk_name);

int nvme_nvm_register(struct nvme_ns *ns, char *disk_name, int node);

void nvme_nvm_unregister(struct nvme_ns *ns);

#else

static inline int nvme_nvm_register(struct request_queue *q, char *disk_name)

static inline int nvme_nvm_register(struct nvme_ns *ns, char *disk_name,

								int node)

{

	return 0;

}



static inline void nvme_nvm_unregister(struct request_queue *q, char *disk_name) {};

static inline void nvme_nvm_unregister(struct nvme_ns *ns) {};



static inline int nvme_nvm_ns_supported(struct nvme_ns *ns, struct nvme_id_ns *id)

{