Merge branch 'for-4.4/lightnvm' of git://git.kernel.dk/linux-block

Pull lightnvm support from Jens Axboe:
 "This adds support for lightnvm, and adds support to NVMe as well.
  This is pretty exciting, in that it enables new and interesting use
  cases for compatible flash devices.  There's a LWN writeup about an
  earlier posting here:

      https://lwn.net/Articles/641247/

  This has been underway for a while, and should be ready for merging at
  this point"

* 'for-4.4/lightnvm' of git://git.kernel.dk/linux-block:
  nvme: lightnvm: clean up a data type
  lightnvm: refactor phys addrs type to u64
  nvme: LightNVM support
  rrpc: Round-robin sector target with cost-based gc
  gennvm: Generic NVM manager
  lightnvm: Support for Open-Channel SSDs

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..e0b7b95813bc
--- /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;
+	u32 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(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 0a179ed9ddef..6c0d0fecaeb3 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1952,6 +1952,9 @@ 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);
@@ -2021,6 +2024,16 @@ 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;
@@ -2052,7 +2065,9 @@ 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));
@@ -2175,17 +2190,19 @@ 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: