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: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c
index 895867a..91e1de8 100644 (file)
--- a/drivers/block/null_blk.c
+++ b/drivers/block/null_blk.c
@@ -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)

diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
index 25c5df9..a99b59d 100644 (file)
--- a/drivers/lightnvm/core.c
+++ b/drivers/lightnvm/core.c
@@ -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);
 

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 2c3da33..3c707d8 100644 (file)
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -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);
 
-       spin_lock(&dev_list_lock);
-       ns->disk->private_data = NULL;
-       spin_unlock(&dev_list_lock);
+       if (ns->disk) {
+               spin_lock(&dev_list_lock);
+               ns->disk->private_data = NULL;
+               spin_unlock(&dev_list_lock);
+       }
 
        put_disk(ns->disk);
        ida_simple_remove(&ns->ctrl->ns_ida, ns->instance);
@@ -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);

diff --git a/drivers/nvme/host/lightnvm.c b/drivers/nvme/host/lightnvm.c
index 7268a7a..798fcd9 100644 (file)
--- a/drivers/nvme/host/lightnvm.c
+++ b/drivers/nvme/host/lightnvm.c
@@ -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. */

diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index ab18b78..e0535c1 100644 (file)
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -18,6 +18,7 @@
 #include <linux/pci.h>
 #include <linux/kref.h>
 #include <linux/blk-mq.h>
+#include <linux/lightnvm.h>
 
 enum {
        /*
@@ -154,6 +155,7 @@ struct nvme_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)
 {

diff --git a/include/linux/lightnvm.h b/include/linux/lightnvm.h
index ba78b83..5afc263 100644 (file)
--- a/include/linux/lightnvm.h
+++ b/include/linux/lightnvm.h
@@ -524,9 +524,9 @@ extern struct nvm_block *nvm_get_blk(struct nvm_dev *, struct nvm_lun *,
                                                                unsigned long);
 extern void nvm_put_blk(struct nvm_dev *, struct nvm_block *);
 
-extern int nvm_register(struct request_queue *, char *,
-                                               struct nvm_dev_ops *);
-extern void nvm_unregister(char *);
+extern struct nvm_dev *nvm_alloc_dev(int);
+extern int nvm_register(struct nvm_dev *);
+extern void nvm_unregister(struct nvm_dev *);
 
 void nvm_mark_blk(struct nvm_dev *dev, struct ppa_addr ppa, int type);
 
@@ -575,11 +575,14 @@ extern int nvm_dev_factory(struct nvm_dev *, int flags);
 #else /* CONFIG_NVM */
 struct nvm_dev_ops;
 
-static inline int nvm_register(struct request_queue *q, char *disk_name,
-                                                       struct nvm_dev_ops *ops)
+static inline struct nvm_dev *nvm_alloc_dev(int node)
+{
+       return ERR_PTR(-EINVAL);
+}
+static inline int nvm_register(struct nvm_dev *dev)
 {
        return -EINVAL;
 }
-static inline void nvm_unregister(char *disk_name) {}
+static inline void nvm_unregister(struct nvm_dev *dev) {}
 #endif /* CONFIG_NVM */
 #endif /* LIGHTNVM.H */