nvme: LightNVM support

The first generation of Open-Channel SSDs is based on NVMe. The NVMe
driver is extended with support for the LightNVM command set.

Detection is made through PCI IDs. Current supported devices are the
qemu nvme simulator and CNEX Labs Westlake SSD. The qemu nvme enables
support through vendor specific bits in the namespace identification and
the CNEX Labs Westlake SSD implements a LightNVM compatible firmware and
is detected using the same method as qemu.

After detection, vendor specific codes are used to identify the device
and enumerate supported features.

Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Javier González <jg@lightnvm.io>
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>

4 files changed, 565 insertions, 12 deletions

diff --git a/drivers/nvme/host/Makefile b/drivers/nvme/host/Makefile
index cfb6679ec245..219dc206fa5f 100644
--- a/drivers/nvme/host/Makefile
+++ b/drivers/nvme/host/Makefile
@@ -1,4 +1,4 @@
 
 obj-$(CONFIG_BLK_DEV_NVME)     += nvme.o
 
-nvme-y          += pci.o scsi.o
+nvme-y          += pci.o scsi.o lightnvm.o
diff --git a/drivers/nvme/host/lightnvm.c b/drivers/nvme/host/lightnvm.c
new file mode 100644
index 000000000000..133c8396ec93
--- /dev/null
+++ b/drivers/nvme/host/lightnvm.c
@@ -0,0 +1,526 @@
+/*
+ * nvme-lightnvm.c - LightNVM NVMe device
+ *
+ * Copyright (C) 2014-2015 IT University of Copenhagen
+ * Initial release: Matias Bjorling <mb@lightnvm.io>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
+ * USA.
+ *
+ */
+
+#include "nvme.h"
+
+#ifdef CONFIG_NVM
+
+#include <linux/nvme.h>
+#include <linux/bitops.h>
+#include <linux/lightnvm.h>
+#include <linux/vmalloc.h>
+
+enum nvme_nvm_admin_opcode {
+        nvme_nvm_admin_identity         = 0xe2,
+        nvme_nvm_admin_get_l2p_tbl      = 0xea,
+        nvme_nvm_admin_get_bb_tbl       = 0xf2,
+        nvme_nvm_admin_set_bb_tbl       = 0xf1,
+};
+
+struct nvme_nvm_hb_rw {
+        __u8                    opcode;
+        __u8                    flags;
+        __u16                   command_id;
+        __le32                  nsid;
+        __u64                   rsvd2;
+        __le64                  metadata;
+        __le64                  prp1;
+        __le64                  prp2;
+        __le64                  spba;
+        __le16                  length;
+        __le16                  control;
+        __le32                  dsmgmt;
+        __le64                  slba;
+};
+
+struct nvme_nvm_ph_rw {
+        __u8                    opcode;
+        __u8                    flags;
+        __u16                   command_id;
+        __le32                  nsid;
+        __u64                   rsvd2;
+        __le64                  metadata;
+        __le64                  prp1;
+        __le64                  prp2;
+        __le64                  spba;
+        __le16                  length;
+        __le16                  control;
+        __le32                  dsmgmt;
+        __le64                  resv;
+};
+
+struct nvme_nvm_identity {
+        __u8                    opcode;
+        __u8                    flags;
+        __u16                   command_id;
+        __le32                  nsid;
+        __u64                   rsvd[2];
+        __le64                  prp1;
+        __le64                  prp2;
+        __le32                  chnl_off;
+        __u32                   rsvd11[5];
+};
+
+struct nvme_nvm_l2ptbl {
+        __u8                    opcode;
+        __u8                    flags;
+        __u16                   command_id;
+        __le32                  nsid;
+        __le32                  cdw2[4];
+        __le64                  prp1;
+        __le64                  prp2;
+        __le64                  slba;
+        __le32                  nlb;
+        __le16                  cdw14[6];
+};
+
+struct nvme_nvm_bbtbl {
+        __u8                    opcode;
+        __u8                    flags;
+        __u16                   command_id;
+        __le32                  nsid;
+        __u64                   rsvd[2];
+        __le64                  prp1;
+        __le64                  prp2;
+        __le32                  prp1_len;
+        __le32                  prp2_len;
+        __le32                  lbb;
+        __u32                   rsvd11[3];
+};
+
+struct nvme_nvm_erase_blk {
+        __u8                    opcode;
+        __u8                    flags;
+        __u16                   command_id;
+        __le32                  nsid;
+        __u64                   rsvd[2];
+        __le64                  prp1;
+        __le64                  prp2;
+        __le64                  spba;
+        __le16                  length;
+        __le16                  control;
+        __le32                  dsmgmt;
+        __le64                  resv;
+};
+
+struct nvme_nvm_command {
+        union {
+                struct nvme_common_command common;
+                struct nvme_nvm_identity identity;
+                struct nvme_nvm_hb_rw hb_rw;
+                struct nvme_nvm_ph_rw ph_rw;
+                struct nvme_nvm_l2ptbl l2p;
+                struct nvme_nvm_bbtbl get_bb;
+                struct nvme_nvm_bbtbl set_bb;
+                struct nvme_nvm_erase_blk erase;
+        };
+};
+
+struct nvme_nvm_id_group {
+        __u8                    mtype;
+        __u8                    fmtype;
+        __le16                  res16;
+        __u8                    num_ch;
+        __u8                    num_lun;
+        __u8                    num_pln;
+        __le16                  num_blk;
+        __le16                  num_pg;
+        __le16                  fpg_sz;
+        __le16                  csecs;
+        __le16                  sos;
+        __le32                  trdt;
+        __le32                  trdm;
+        __le32                  tprt;
+        __le32                  tprm;
+        __le32                  tbet;
+        __le32                  tbem;
+        __le32                  mpos;
+        __le16                  cpar;
+        __u8                    reserved[913];
+} __packed;
+
+struct nvme_nvm_addr_format {
+        __u8                    ch_offset;
+        __u8                    ch_len;
+        __u8                    lun_offset;
+        __u8                    lun_len;
+        __u8                    pln_offset;
+        __u8                    pln_len;
+        __u8                    blk_offset;
+        __u8                    blk_len;
+        __u8                    pg_offset;
+        __u8                    pg_len;
+        __u8                    sect_offset;
+        __u8                    sect_len;
+        __u8                    res[4];
+} __packed;
+
+struct nvme_nvm_id {
+        __u8                    ver_id;
+        __u8                    vmnt;
+        __u8                    cgrps;
+        __u8                    res[5];
+        __le32                  cap;
+        __le32                  dom;
+        struct nvme_nvm_addr_format ppaf;
+        __u8                    ppat;
+        __u8                    resv[223];
+        struct nvme_nvm_id_group groups[4];
+} __packed;
+
+/*
+ * Check we didn't inadvertently grow the command struct
+ */
+static inline void _nvme_nvm_check_size(void)
+{
+        BUILD_BUG_ON(sizeof(struct nvme_nvm_identity) != 64);
+        BUILD_BUG_ON(sizeof(struct nvme_nvm_hb_rw) != 64);
+        BUILD_BUG_ON(sizeof(struct nvme_nvm_ph_rw) != 64);
+        BUILD_BUG_ON(sizeof(struct nvme_nvm_bbtbl) != 64);
+        BUILD_BUG_ON(sizeof(struct nvme_nvm_l2ptbl) != 64);
+        BUILD_BUG_ON(sizeof(struct nvme_nvm_erase_blk) != 64);
+        BUILD_BUG_ON(sizeof(struct nvme_nvm_id_group) != 960);
+        BUILD_BUG_ON(sizeof(struct nvme_nvm_addr_format) != 128);
+        BUILD_BUG_ON(sizeof(struct nvme_nvm_id) != 4096);
+}
+
+static int init_grps(struct nvm_id *nvm_id, struct nvme_nvm_id *nvme_nvm_id)
+{
+        struct nvme_nvm_id_group *src;
+        struct nvm_id_group *dst;
+        int i, end;
+
+        end = min_t(u32, 4, nvm_id->cgrps);
+
+        for (i = 0; i < end; i++) {
+                src = &nvme_nvm_id->groups[i];
+                dst = &nvm_id->groups[i];
+
+                dst->mtype = src->mtype;
+                dst->fmtype = src->fmtype;
+                dst->num_ch = src->num_ch;
+                dst->num_lun = src->num_lun;
+                dst->num_pln = src->num_pln;
+
+                dst->num_pg = le16_to_cpu(src->num_pg);
+                dst->num_blk = le16_to_cpu(src->num_blk);
+                dst->fpg_sz = le16_to_cpu(src->fpg_sz);
+                dst->csecs = le16_to_cpu(src->csecs);
+                dst->sos = le16_to_cpu(src->sos);
+
+                dst->trdt = le32_to_cpu(src->trdt);
+                dst->trdm = le32_to_cpu(src->trdm);
+                dst->tprt = le32_to_cpu(src->tprt);
+                dst->tprm = le32_to_cpu(src->tprm);
+                dst->tbet = le32_to_cpu(src->tbet);
+                dst->tbem = le32_to_cpu(src->tbem);
+                dst->mpos = le32_to_cpu(src->mpos);
+
+                dst->cpar = le16_to_cpu(src->cpar);
+        }
+
+        return 0;
+}
+
+static int nvme_nvm_identity(struct request_queue *q, struct nvm_id *nvm_id)
+{
+        struct nvme_ns *ns = q->queuedata;
+        struct nvme_nvm_id *nvme_nvm_id;
+        struct nvme_nvm_command c = {};
+        int ret;
+
+        c.identity.opcode = nvme_nvm_admin_identity;
+        c.identity.nsid = cpu_to_le32(ns->ns_id);
+        c.identity.chnl_off = 0;
+
+        nvme_nvm_id = kmalloc(sizeof(struct nvme_nvm_id), GFP_KERNEL);
+        if (!nvme_nvm_id)
+                return -ENOMEM;
+
+        ret = nvme_submit_sync_cmd(q, (struct nvme_command *)&c, nvme_nvm_id,
+                                                sizeof(struct nvme_nvm_id));
+        if (ret) {
+                ret = -EIO;
+                goto out;
+        }
+
+        nvm_id->ver_id = nvme_nvm_id->ver_id;
+        nvm_id->vmnt = nvme_nvm_id->vmnt;
+        nvm_id->cgrps = nvme_nvm_id->cgrps;
+        nvm_id->cap = le32_to_cpu(nvme_nvm_id->cap);
+        nvm_id->dom = le32_to_cpu(nvme_nvm_id->dom);
+
+        ret = init_grps(nvm_id, nvme_nvm_id);
+out:
+        kfree(nvme_nvm_id);
+        return ret;
+}
+
+static int nvme_nvm_get_l2p_tbl(struct request_queue *q, u64 slba, u32 nlb,
+                                nvm_l2p_update_fn *update_l2p, void *priv)
+{
+        struct nvme_ns *ns = q->queuedata;
+        struct nvme_dev *dev = ns->dev;
+        struct nvme_nvm_command c = {};
+        u32 len = queue_max_hw_sectors(q) << 9;
+        u64 nlb_pr_rq = len / sizeof(u64);
+        u64 cmd_slba = slba;
+        void *entries;
+        int ret = 0;
+
+        c.l2p.opcode = nvme_nvm_admin_get_l2p_tbl;
+        c.l2p.nsid = cpu_to_le32(ns->ns_id);
+        entries = kmalloc(len, GFP_KERNEL);
+        if (!entries)
+                return -ENOMEM;
+
+        while (nlb) {
+                u32 cmd_nlb = min_t(u32, nlb_pr_rq, nlb);
+
+                c.l2p.slba = cpu_to_le64(cmd_slba);
+                c.l2p.nlb = cpu_to_le32(cmd_nlb);
+
+                ret = nvme_submit_sync_cmd(q, (struct nvme_command *)&c,
+                                                                entries, len);
+                if (ret) {
+                        dev_err(dev->dev, "L2P table transfer failed (%d)\n",
+                                                                        ret);
+                        ret = -EIO;
+                        goto out;
+                }
+
+                if (update_l2p(cmd_slba, cmd_nlb, entries, priv)) {
+                        ret = -EINTR;
+                        goto out;
+                }
+
+                cmd_slba += cmd_nlb;
+                nlb -= cmd_nlb;
+        }
+
+out:
+        kfree(entries);
+        return ret;
+}
+
+static int nvme_nvm_get_bb_tbl(struct request_queue *q, int lunid,
+                                unsigned int nr_blocks,
+                                nvm_bb_update_fn *update_bbtbl, void *priv)
+{
+        struct nvme_ns *ns = q->queuedata;
+        struct nvme_dev *dev = ns->dev;
+        struct nvme_nvm_command c = {};
+        void *bb_bitmap;
+        u16 bb_bitmap_size;
+        int ret = 0;
+
+        c.get_bb.opcode = nvme_nvm_admin_get_bb_tbl;
+        c.get_bb.nsid = cpu_to_le32(ns->ns_id);
+        c.get_bb.lbb = cpu_to_le32(lunid);
+        bb_bitmap_size = ((nr_blocks >> 15) + 1) * PAGE_SIZE;
+        bb_bitmap = kmalloc(bb_bitmap_size, GFP_KERNEL);
+        if (!bb_bitmap)
+                return -ENOMEM;
+
+        bitmap_zero(bb_bitmap, nr_blocks);
+
+        ret = nvme_submit_sync_cmd(q, (struct nvme_command *)&c, bb_bitmap,
+                                                                bb_bitmap_size);
+        if (ret) {
+                dev_err(dev->dev, "get bad block table failed (%d)\n", ret);
+                ret = -EIO;
+                goto out;
+        }
+
+        ret = update_bbtbl(lunid, bb_bitmap, nr_blocks, priv);
+        if (ret) {
+                ret = -EINTR;
+                goto out;
+        }
+
+out:
+        kfree(bb_bitmap);
+        return ret;
+}
+
+static inline void nvme_nvm_rqtocmd(struct request *rq, struct nvm_rq *rqd,
+                                struct nvme_ns *ns, struct nvme_nvm_command *c)
+{
+        c->ph_rw.opcode = rqd->opcode;
+        c->ph_rw.nsid = cpu_to_le32(ns->ns_id);
+        c->ph_rw.spba = cpu_to_le64(rqd->ppa_addr.ppa);
+        c->ph_rw.control = cpu_to_le16(rqd->flags);
+        c->ph_rw.length = cpu_to_le16(rqd->nr_pages - 1);
+
+        if (rqd->opcode == NVM_OP_HBWRITE || rqd->opcode == NVM_OP_HBREAD)
+                c->hb_rw.slba = cpu_to_le64(nvme_block_nr(ns,
+                                                rqd->bio->bi_iter.bi_sector));
+}
+
+static void nvme_nvm_end_io(struct request *rq, int error)
+{
+        struct nvm_rq *rqd = rq->end_io_data;
+        struct nvm_dev *dev = rqd->dev;
+
+        if (dev->mt->end_io(rqd, error))
+                pr_err("nvme: err status: %x result: %lx\n",
+                                rq->errors, (unsigned long)rq->special);
+
+        kfree(rq->cmd);
+        blk_mq_free_request(rq);
+}
+
+static int nvme_nvm_submit_io(struct request_queue *q, struct nvm_rq *rqd)
+{
+        struct nvme_ns *ns = q->queuedata;
+        struct request *rq;
+        struct bio *bio = rqd->bio;
+        struct nvme_nvm_command *cmd;
+
+        rq = blk_mq_alloc_request(q, bio_rw(bio), GFP_KERNEL, 0);
+        if (IS_ERR(rq))
+                return -ENOMEM;
+
+        cmd = kzalloc(sizeof(struct nvme_nvm_command), GFP_KERNEL);
+        if (!cmd) {
+                blk_mq_free_request(rq);
+                return -ENOMEM;
+        }
+
+        rq->cmd_type = REQ_TYPE_DRV_PRIV;
+        rq->ioprio = bio_prio(bio);
+
+        if (bio_has_data(bio))
+                rq->nr_phys_segments = bio_phys_segments(q, bio);
+
+        rq->__data_len = bio->bi_iter.bi_size;
+        rq->bio = rq->biotail = bio;
+
+        nvme_nvm_rqtocmd(rq, rqd, ns, cmd);
+
+        rq->cmd = (unsigned char *)cmd;
+        rq->cmd_len = sizeof(struct nvme_nvm_command);
+        rq->special = (void *)0;
+
+        rq->end_io_data = rqd;
+
+        blk_execute_rq_nowait(q, NULL, rq, 0, nvme_nvm_end_io);
+
+        return 0;
+}
+
+static int nvme_nvm_erase_block(struct request_queue *q, struct nvm_rq *rqd)
+{
+        struct nvme_ns *ns = q->queuedata;
+        struct nvme_nvm_command c = {};
+
+        c.erase.opcode = NVM_OP_ERASE;
+        c.erase.nsid = cpu_to_le32(ns->ns_id);
+        c.erase.spba = cpu_to_le64(rqd->ppa_addr.ppa);
+        c.erase.length = cpu_to_le16(rqd->nr_pages - 1);
+
+        return nvme_submit_sync_cmd(q, (struct nvme_command *)&c, NULL, 0);
+}
+
+static void *nvme_nvm_create_dma_pool(struct request_queue *q, char *name)
+{
+        struct nvme_ns *ns = q->queuedata;
+        struct nvme_dev *dev = ns->dev;
+
+        return dma_pool_create(name, dev->dev, PAGE_SIZE, PAGE_SIZE, 0);
+}
+
+static void nvme_nvm_destroy_dma_pool(void *pool)
+{
+        struct dma_pool *dma_pool = pool;
+
+        dma_pool_destroy(dma_pool);
+}
+
+static void *nvme_nvm_dev_dma_alloc(struct request_queue *q, void *pool,
+                                    gfp_t mem_flags, dma_addr_t *dma_handler)
+{
+        return dma_pool_alloc(pool, mem_flags, dma_handler);
+}
+
+static void nvme_nvm_dev_dma_free(void *pool, void *ppa_list,
+                                                        dma_addr_t dma_handler)
+{
+        dma_pool_free(pool, ppa_list, dma_handler);
+}
+
+static struct nvm_dev_ops nvme_nvm_dev_ops = {
+        .identity               = nvme_nvm_identity,
+
+        .get_l2p_tbl            = nvme_nvm_get_l2p_tbl,
+
+        .get_bb_tbl             = nvme_nvm_get_bb_tbl,
+
+        .submit_io              = nvme_nvm_submit_io,
+        .erase_block            = nvme_nvm_erase_block,
+
+        .create_dma_pool        = nvme_nvm_create_dma_pool,
+        .destroy_dma_pool       = nvme_nvm_destroy_dma_pool,
+        .dev_dma_alloc          = nvme_nvm_dev_dma_alloc,
+        .dev_dma_free           = nvme_nvm_dev_dma_free,
+
+        .max_phys_sect          = 64,
+};
+
+int nvme_nvm_register(struct request_queue *q, char *disk_name)
+{
+        return nvm_register(q, disk_name, &nvme_nvm_dev_ops);
+}
+
+void nvme_nvm_unregister(struct request_queue *q, char *disk_name)
+{
+        nvm_unregister(disk_name);
+}
+
+int nvme_nvm_ns_supported(struct nvme_ns *ns, struct nvme_id_ns *id)
+{
+        struct nvme_dev *dev = ns->dev;
+        struct pci_dev *pdev = to_pci_dev(dev->dev);
+
+        /* QEMU NVMe simulator - PCI ID + Vendor specific bit */
+        if (pdev->vendor == PCI_VENDOR_ID_INTEL && pdev->device == 0x5845 &&
+                                                        id->vs[0] == 0x1)
+                return 1;
+
+        /* CNEX Labs - PCI ID + Vendor specific bit */
+        if (pdev->vendor == 0x1d1d && pdev->device == 0x2807 &&
+                                                        id->vs[0] == 0x1)
+                return 1;
+
+        return 0;
+}
+#else
+int nvme_nvm_register(struct request_queue *q, char *disk_name)
+{
+        return 0;
+}
+void nvme_nvm_unregister(struct request_queue *q, char *disk_name) {};
+int nvme_nvm_ns_supported(struct nvme_ns *ns, struct nvme_id_ns *id)
+{
+        return 0;
+}
+#endif /* CONFIG_NVM */
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index c1f41bf3c0f2..fdb4e5bad9ac 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -22,6 +22,11 @@
 extern unsigned char nvme_io_timeout;
 #define NVME_IO_TIMEOUT (nvme_io_timeout * HZ)
 
+enum {
+        NVME_NS_LBA             = 0,
+        NVME_NS_LIGHTNVM        = 1,
+};
+
 /*
  * Represents an NVM Express device.  Each nvme_dev is a PCI function.
  */
@@ -84,6 +89,7 @@ struct nvme_ns {
         u16 ms;
         bool ext;
         u8 pi_type;
+        int type;
         u64 mode_select_num_blocks;
         u32 mode_select_block_len;
 };
@@ -130,4 +136,8 @@ int nvme_sg_io(struct nvme_ns *ns, struct sg_io_hdr __user *u_hdr);
 int nvme_sg_io32(struct nvme_ns *ns, unsigned long arg);
 int nvme_sg_get_version_num(int __user *ip);
 
+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);
+
 #endif /* _NVME_H */
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 22d83752ae87..ff47a8b62f68 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1948,6 +1948,9 @@ 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);
+
         spin_lock(&dev_list_lock);
         ns->disk->private_data = NULL;
         spin_unlock(&dev_list_lock);
@@ -2017,6 +2020,16 @@ static int nvme_revalidate_disk(struct gendisk *disk)
                 return -ENODEV;
         }
 
+        if (nvme_nvm_ns_supported(ns, id) && ns->type != NVME_NS_LIGHTNVM) {
+                if (nvme_nvm_register(ns->queue, disk->disk_name)) {
+                        dev_warn(dev->dev,
+                                "%s: LightNVM init failure\n", __func__);
+                        kfree(id);
+                        return -ENODEV;
+                }
+                ns->type = NVME_NS_LIGHTNVM;
+        }
+
         old_ms = ns->ms;
         lbaf = id->flbas & NVME_NS_FLBAS_LBA_MASK;
         ns->lba_shift = id->lbaf[lbaf].ds;
@@ -2048,7 +2061,9 @@ static int nvme_revalidate_disk(struct gendisk *disk)
                                                                 !ns->ext)
                 nvme_init_integrity(ns);
 
-        if (ns->ms && !(ns->ms == 8 && ns->pi_type) && !blk_get_integrity(disk))
+        if ((ns->ms && !(ns->ms == 8 && ns->pi_type) &&
+                                                !blk_get_integrity(disk)) ||
+                                                ns->type == NVME_NS_LIGHTNVM)
                 set_capacity(disk, 0);
         else
                 set_capacity(disk, le64_to_cpup(&id->nsze) << (ns->lba_shift - 9));
@@ -2171,17 +2186,19 @@ static void nvme_alloc_ns(struct nvme_dev *dev, unsigned nsid)
                 goto out_free_disk;
 
         kref_get(&dev->kref);
-        add_disk(ns->disk);
-        if (ns->ms) {
-                struct block_device *bd = bdget_disk(ns->disk, 0);
-                if (!bd)
-                        return;
-                if (blkdev_get(bd, FMODE_READ, NULL)) {
-                        bdput(bd);
-                        return;
+        if (ns->type != NVME_NS_LIGHTNVM) {
+                add_disk(ns->disk);
+                if (ns->ms) {
+                        struct block_device *bd = bdget_disk(ns->disk, 0);
+                        if (!bd)
+                                return;
+                        if (blkdev_get(bd, FMODE_READ, NULL)) {
+                                bdput(bd);
+                                return;
+                        }
+                        blkdev_reread_part(bd);
+                        blkdev_put(bd, FMODE_READ);
                 }
-                blkdev_reread_part(bd);
-                blkdev_put(bd, FMODE_READ);
         }
         return;
  out_free_disk: