Commit e1455744 authored by Dan Williams's avatar Dan Williams

libnvdimm, pfn: 'struct page' provider infrastructure

Implement the base infrastructure for libnvdimm PFN devices. Similar to
BTT devices they take a namespace as a backing device and layer
functionality on top. In this case the functionality is reserving space
for an array of 'struct page' entries to be handed out through
pfn_to_page(). For now this is just the basic libnvdimm-device-model for
configuring the base PFN device.

As the namespace claiming mechanism for PFN devices is mostly identical
to BTT devices drivers/nvdimm/claim.c is created to house the common
bits.

Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 96601adb
......@@ -21,6 +21,7 @@ config BLK_DEV_PMEM
default LIBNVDIMM
depends on HAS_IOMEM
select ND_BTT if BTT
select ND_PFN if NVDIMM_PFN
help
Memory ranges for PMEM are described by either an NFIT
(NVDIMM Firmware Interface Table, see CONFIG_NFIT_ACPI), a
......@@ -47,12 +48,16 @@ config ND_BLK
(CONFIG_ACPI_NFIT), or otherwise exposes BLK-mode
capabilities.
config ND_CLAIM
bool
config ND_BTT
tristate
config BTT
bool "BTT: Block Translation Table (atomic sector updates)"
default y if LIBNVDIMM
select ND_CLAIM
help
The Block Translation Table (BTT) provides atomic sector
update semantics for persistent memory devices, so that
......@@ -65,4 +70,21 @@ config BTT
Select Y if unsure
config ND_PFN
tristate
config NVDIMM_PFN
bool "PFN: Map persistent (device) memory"
default LIBNVDIMM
select ND_CLAIM
help
Map persistent memory, i.e. advertise it to the memory
management sub-system. By default persistent memory does
not support direct I/O, RDMA, or any other usage that
requires a 'struct page' to mediate an I/O request. This
driver allocates and initializes the infrastructure needed
to support those use cases.
Select Y if unsure
endif
......@@ -20,4 +20,6 @@ libnvdimm-y += region_devs.o
libnvdimm-y += region.o
libnvdimm-y += namespace_devs.o
libnvdimm-y += label.o
libnvdimm-$(CONFIG_ND_CLAIM) += claim.o
libnvdimm-$(CONFIG_BTT) += btt_devs.o
libnvdimm-$(CONFIG_NVDIMM_PFN) += pfn_devs.o
......@@ -731,6 +731,7 @@ static int create_arenas(struct btt *btt)
static int btt_arena_write_layout(struct arena_info *arena)
{
int ret;
u64 sum;
struct btt_sb *super;
struct nd_btt *nd_btt = arena->nd_btt;
const u8 *parent_uuid = nd_dev_to_uuid(&nd_btt->ndns->dev);
......@@ -770,7 +771,8 @@ static int btt_arena_write_layout(struct arena_info *arena)
super->info2off = cpu_to_le64(arena->info2off - arena->infooff);
super->flags = 0;
super->checksum = cpu_to_le64(nd_btt_sb_checksum(super));
sum = nd_sb_checksum((struct nd_gen_sb *) super);
super->checksum = cpu_to_le64(sum);
ret = btt_info_write(arena, super);
......@@ -1422,8 +1424,6 @@ static int __init nd_btt_init(void)
{
int rc;
BUILD_BUG_ON(sizeof(struct btt_sb) != SZ_4K);
btt_major = register_blkdev(0, "btt");
if (btt_major < 0)
return btt_major;
......
......@@ -21,63 +21,13 @@
#include "btt.h"
#include "nd.h"
static void __nd_btt_detach_ndns(struct nd_btt *nd_btt)
{
struct nd_namespace_common *ndns = nd_btt->ndns;
dev_WARN_ONCE(&nd_btt->dev, !mutex_is_locked(&ndns->dev.mutex)
|| ndns->claim != &nd_btt->dev,
"%s: invalid claim\n", __func__);
ndns->claim = NULL;
nd_btt->ndns = NULL;
put_device(&ndns->dev);
}
static void nd_btt_detach_ndns(struct nd_btt *nd_btt)
{
struct nd_namespace_common *ndns = nd_btt->ndns;
if (!ndns)
return;
get_device(&ndns->dev);
device_lock(&ndns->dev);
__nd_btt_detach_ndns(nd_btt);
device_unlock(&ndns->dev);
put_device(&ndns->dev);
}
static bool __nd_btt_attach_ndns(struct nd_btt *nd_btt,
struct nd_namespace_common *ndns)
{
if (ndns->claim)
return false;
dev_WARN_ONCE(&nd_btt->dev, !mutex_is_locked(&ndns->dev.mutex)
|| nd_btt->ndns,
"%s: invalid claim\n", __func__);
ndns->claim = &nd_btt->dev;
nd_btt->ndns = ndns;
get_device(&ndns->dev);
return true;
}
static bool nd_btt_attach_ndns(struct nd_btt *nd_btt,
struct nd_namespace_common *ndns)
{
bool claimed;
device_lock(&ndns->dev);
claimed = __nd_btt_attach_ndns(nd_btt, ndns);
device_unlock(&ndns->dev);
return claimed;
}
static void nd_btt_release(struct device *dev)
{
struct nd_region *nd_region = to_nd_region(dev->parent);
struct nd_btt *nd_btt = to_nd_btt(dev);
dev_dbg(dev, "%s\n", __func__);
nd_btt_detach_ndns(nd_btt);
nd_detach_ndns(&nd_btt->dev, &nd_btt->ndns);
ida_simple_remove(&nd_region->btt_ida, nd_btt->id);
kfree(nd_btt->uuid);
kfree(nd_btt);
......@@ -172,104 +122,15 @@ static ssize_t namespace_show(struct device *dev,
return rc;
}
static int namespace_match(struct device *dev, void *data)
{
char *name = data;
return strcmp(name, dev_name(dev)) == 0;
}
static bool is_nd_btt_idle(struct device *dev)
{
struct nd_region *nd_region = to_nd_region(dev->parent);
struct nd_btt *nd_btt = to_nd_btt(dev);
if (nd_region->btt_seed == dev || nd_btt->ndns || dev->driver)
return false;
return true;
}
static ssize_t __namespace_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t len)
{
struct nd_btt *nd_btt = to_nd_btt(dev);
struct nd_namespace_common *ndns;
struct device *found;
char *name;
if (dev->driver) {
dev_dbg(dev, "%s: -EBUSY\n", __func__);
return -EBUSY;
}
name = kstrndup(buf, len, GFP_KERNEL);
if (!name)
return -ENOMEM;
strim(name);
if (strncmp(name, "namespace", 9) == 0 || strcmp(name, "") == 0)
/* pass */;
else {
len = -EINVAL;
goto out;
}
ndns = nd_btt->ndns;
if (strcmp(name, "") == 0) {
/* detach the namespace and destroy / reset the btt device */
nd_btt_detach_ndns(nd_btt);
if (is_nd_btt_idle(dev))
nd_device_unregister(dev, ND_ASYNC);
else {
nd_btt->lbasize = 0;
kfree(nd_btt->uuid);
nd_btt->uuid = NULL;
}
goto out;
} else if (ndns) {
dev_dbg(dev, "namespace already set to: %s\n",
dev_name(&ndns->dev));
len = -EBUSY;
goto out;
}
found = device_find_child(dev->parent, name, namespace_match);
if (!found) {
dev_dbg(dev, "'%s' not found under %s\n", name,
dev_name(dev->parent));
len = -ENODEV;
goto out;
}
ndns = to_ndns(found);
if (__nvdimm_namespace_capacity(ndns) < SZ_16M) {
dev_dbg(dev, "%s too small to host btt\n", name);
len = -ENXIO;
goto out_attach;
}
WARN_ON_ONCE(!is_nvdimm_bus_locked(&nd_btt->dev));
if (!nd_btt_attach_ndns(nd_btt, ndns)) {
dev_dbg(dev, "%s already claimed\n",
dev_name(&ndns->dev));
len = -EBUSY;
}
out_attach:
put_device(&ndns->dev); /* from device_find_child */
out:
kfree(name);
return len;
}
static ssize_t namespace_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t len)
{
struct nd_btt *nd_btt = to_nd_btt(dev);
ssize_t rc;
nvdimm_bus_lock(dev);
device_lock(dev);
rc = __namespace_store(dev, attr, buf, len);
rc = nd_namespace_store(dev, &nd_btt->ndns, buf, len);
dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
rc, buf, buf[len - 1] == '\n' ? "" : "\n");
device_unlock(dev);
......@@ -324,7 +185,7 @@ static struct device *__nd_btt_create(struct nd_region *nd_region,
dev->type = &nd_btt_device_type;
dev->groups = nd_btt_attribute_groups;
device_initialize(&nd_btt->dev);
if (ndns && !__nd_btt_attach_ndns(nd_btt, ndns)) {
if (ndns && !__nd_attach_ndns(&nd_btt->dev, ndns, &nd_btt->ndns)) {
dev_dbg(&ndns->dev, "%s failed, already claimed by %s\n",
__func__, dev_name(ndns->claim));
put_device(dev);
......@@ -375,7 +236,7 @@ bool nd_btt_arena_is_valid(struct nd_btt *nd_btt, struct btt_sb *super)
checksum = le64_to_cpu(super->checksum);
super->checksum = 0;
if (checksum != nd_btt_sb_checksum(super))
if (checksum != nd_sb_checksum((struct nd_gen_sb *) super))
return false;
super->checksum = cpu_to_le64(checksum);
......@@ -387,25 +248,6 @@ bool nd_btt_arena_is_valid(struct nd_btt *nd_btt, struct btt_sb *super)
}
EXPORT_SYMBOL(nd_btt_arena_is_valid);
/*
* nd_btt_sb_checksum: compute checksum for btt info block
*
* Returns a fletcher64 checksum of everything in the given info block
* except the last field (since that's where the checksum lives).
*/
u64 nd_btt_sb_checksum(struct btt_sb *btt_sb)
{
u64 sum;
__le64 sum_save;
sum_save = btt_sb->checksum;
btt_sb->checksum = 0;
sum = nd_fletcher64(btt_sb, sizeof(*btt_sb), 1);
btt_sb->checksum = sum_save;
return sum;
}
EXPORT_SYMBOL(nd_btt_sb_checksum);
static int __nd_btt_probe(struct nd_btt *nd_btt,
struct nd_namespace_common *ndns, struct btt_sb *btt_sb)
{
......@@ -453,7 +295,9 @@ int nd_btt_probe(struct nd_namespace_common *ndns, void *drvdata)
dev_dbg(&ndns->dev, "%s: btt: %s\n", __func__,
rc == 0 ? dev_name(dev) : "<none>");
if (rc < 0) {
__nd_btt_detach_ndns(to_nd_btt(dev));
struct nd_btt *nd_btt = to_nd_btt(dev);
__nd_detach_ndns(dev, &nd_btt->ndns);
put_device(dev);
}
......
/*
* Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License 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.
*/
#include <linux/device.h>
#include <linux/sizes.h>
#include "nd-core.h"
#include "pfn.h"
#include "btt.h"
#include "nd.h"
void __nd_detach_ndns(struct device *dev, struct nd_namespace_common **_ndns)
{
struct nd_namespace_common *ndns = *_ndns;
dev_WARN_ONCE(dev, !mutex_is_locked(&ndns->dev.mutex)
|| ndns->claim != dev,
"%s: invalid claim\n", __func__);
ndns->claim = NULL;
*_ndns = NULL;
put_device(&ndns->dev);
}
void nd_detach_ndns(struct device *dev,
struct nd_namespace_common **_ndns)
{
struct nd_namespace_common *ndns = *_ndns;
if (!ndns)
return;
get_device(&ndns->dev);
device_lock(&ndns->dev);
__nd_detach_ndns(dev, _ndns);
device_unlock(&ndns->dev);
put_device(&ndns->dev);
}
bool __nd_attach_ndns(struct device *dev, struct nd_namespace_common *attach,
struct nd_namespace_common **_ndns)
{
if (attach->claim)
return false;
dev_WARN_ONCE(dev, !mutex_is_locked(&attach->dev.mutex)
|| *_ndns,
"%s: invalid claim\n", __func__);
attach->claim = dev;
*_ndns = attach;
get_device(&attach->dev);
return true;
}
bool nd_attach_ndns(struct device *dev, struct nd_namespace_common *attach,
struct nd_namespace_common **_ndns)
{
bool claimed;
device_lock(&attach->dev);
claimed = __nd_attach_ndns(dev, attach, _ndns);
device_unlock(&attach->dev);
return claimed;
}
static int namespace_match(struct device *dev, void *data)
{
char *name = data;
return strcmp(name, dev_name(dev)) == 0;
}
static bool is_idle(struct device *dev, struct nd_namespace_common *ndns)
{
struct nd_region *nd_region = to_nd_region(dev->parent);
struct device *seed = NULL;
if (is_nd_btt(dev))
seed = nd_region->btt_seed;
else if (is_nd_pfn(dev))
seed = nd_region->pfn_seed;
if (seed == dev || ndns || dev->driver)
return false;
return true;
}
static void nd_detach_and_reset(struct device *dev,
struct nd_namespace_common **_ndns)
{
/* detach the namespace and destroy / reset the device */
nd_detach_ndns(dev, _ndns);
if (is_idle(dev, *_ndns)) {
nd_device_unregister(dev, ND_ASYNC);
} else if (is_nd_btt(dev)) {
struct nd_btt *nd_btt = to_nd_btt(dev);
nd_btt->lbasize = 0;
kfree(nd_btt->uuid);
nd_btt->uuid = NULL;
} else if (is_nd_pfn(dev)) {
struct nd_pfn *nd_pfn = to_nd_pfn(dev);
kfree(nd_pfn->uuid);
nd_pfn->uuid = NULL;
nd_pfn->mode = PFN_MODE_NONE;
}
}
ssize_t nd_namespace_store(struct device *dev,
struct nd_namespace_common **_ndns, const char *buf,
size_t len)
{
struct nd_namespace_common *ndns;
struct device *found;
char *name;
if (dev->driver) {
dev_dbg(dev, "%s: -EBUSY\n", __func__);
return -EBUSY;
}
name = kstrndup(buf, len, GFP_KERNEL);
if (!name)
return -ENOMEM;
strim(name);
if (strncmp(name, "namespace", 9) == 0 || strcmp(name, "") == 0)
/* pass */;
else {
len = -EINVAL;
goto out;
}
ndns = *_ndns;
if (strcmp(name, "") == 0) {
nd_detach_and_reset(dev, _ndns);
goto out;
} else if (ndns) {
dev_dbg(dev, "namespace already set to: %s\n",
dev_name(&ndns->dev));
len = -EBUSY;
goto out;
}
found = device_find_child(dev->parent, name, namespace_match);
if (!found) {
dev_dbg(dev, "'%s' not found under %s\n", name,
dev_name(dev->parent));
len = -ENODEV;
goto out;
}
ndns = to_ndns(found);
if (__nvdimm_namespace_capacity(ndns) < SZ_16M) {
dev_dbg(dev, "%s too small to host\n", name);
len = -ENXIO;
goto out_attach;
}
WARN_ON_ONCE(!is_nvdimm_bus_locked(dev));
if (!nd_attach_ndns(dev, ndns, _ndns)) {
dev_dbg(dev, "%s already claimed\n",
dev_name(&ndns->dev));
len = -EBUSY;
}
out_attach:
put_device(&ndns->dev); /* from device_find_child */
out:
kfree(name);
return len;
}
/*
* nd_sb_checksum: compute checksum for a generic info block
*
* Returns a fletcher64 checksum of everything in the given info block
* except the last field (since that's where the checksum lives).
*/
u64 nd_sb_checksum(struct nd_gen_sb *nd_gen_sb)
{
u64 sum;
__le64 sum_save;
BUILD_BUG_ON(sizeof(struct btt_sb) != SZ_4K);
BUILD_BUG_ON(sizeof(struct nd_pfn_sb) != SZ_4K);
BUILD_BUG_ON(sizeof(struct nd_gen_sb) != SZ_4K);
sum_save = nd_gen_sb->checksum;
nd_gen_sb->checksum = 0;
sum = nd_fletcher64(nd_gen_sb, sizeof(*nd_gen_sb), 1);
nd_gen_sb->checksum = sum_save;
return sum;
}
EXPORT_SYMBOL(nd_sb_checksum);
......@@ -82,8 +82,16 @@ const char *nvdimm_namespace_disk_name(struct nd_namespace_common *ndns,
struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
const char *suffix = "";
if (ndns->claim && is_nd_btt(ndns->claim))
suffix = "s";
if (ndns->claim) {
if (is_nd_btt(ndns->claim))
suffix = "s";
else if (is_nd_pfn(ndns->claim))
suffix = "m";
else
dev_WARN_ONCE(&ndns->dev, 1,
"unknown claim type by %s\n",
dev_name(ndns->claim));
}
if (is_namespace_pmem(&ndns->dev) || is_namespace_io(&ndns->dev))
sprintf(name, "pmem%d%s", nd_region->id, suffix);
......@@ -1255,12 +1263,22 @@ static const struct attribute_group *nd_namespace_attribute_groups[] = {
struct nd_namespace_common *nvdimm_namespace_common_probe(struct device *dev)
{
struct nd_btt *nd_btt = is_nd_btt(dev) ? to_nd_btt(dev) : NULL;
struct nd_pfn *nd_pfn = is_nd_pfn(dev) ? to_nd_pfn(dev) : NULL;
struct nd_namespace_common *ndns;
resource_size_t size;
if (nd_btt) {
ndns = nd_btt->ndns;
if (!ndns)
if (nd_btt || nd_pfn) {
struct device *host = NULL;
if (nd_btt) {
host = &nd_btt->dev;
ndns = nd_btt->ndns;
} else if (nd_pfn) {
host = &nd_pfn->dev;
ndns = nd_pfn->ndns;
}
if (!ndns || !host)
return ERR_PTR(-ENODEV);
/*
......@@ -1271,12 +1289,12 @@ struct nd_namespace_common *nvdimm_namespace_common_probe(struct device *dev)
device_unlock(&ndns->dev);
if (ndns->dev.driver) {
dev_dbg(&ndns->dev, "is active, can't bind %s\n",
dev_name(&nd_btt->dev));
dev_name(host));
return ERR_PTR(-EBUSY);
}
if (dev_WARN_ONCE(&ndns->dev, ndns->claim != &nd_btt->dev,
if (dev_WARN_ONCE(&ndns->dev, ndns->claim != host,
"host (%s) vs claim (%s) mismatch\n",
dev_name(&nd_btt->dev),
dev_name(host),
dev_name(ndns->claim)))
return ERR_PTR(-ENXIO);
} else {
......
......@@ -80,4 +80,13 @@ struct resource *nsblk_add_resource(struct nd_region *nd_region,
int nvdimm_num_label_slots(struct nvdimm_drvdata *ndd);
void get_ndd(struct nvdimm_drvdata *ndd);
resource_size_t __nvdimm_namespace_capacity(struct nd_namespace_common *ndns);
void nd_detach_ndns(struct device *dev, struct nd_namespace_common **_ndns);
void __nd_detach_ndns(struct device *dev, struct nd_namespace_common **_ndns);
bool nd_attach_ndns(struct device *dev, struct nd_namespace_common *attach,
struct nd_namespace_common **_ndns);
bool __nd_attach_ndns(struct device *dev, struct nd_namespace_common *attach,
struct nd_namespace_common **_ndns);
ssize_t nd_namespace_store(struct device *dev,
struct nd_namespace_common **_ndns, const char *buf,
size_t len);
#endif /* __ND_CORE_H__ */
......@@ -29,6 +29,13 @@ enum {
ND_MAX_LANES = 256,
SECTOR_SHIFT = 9,
INT_LBASIZE_ALIGNMENT = 64,
#if IS_ENABLED(CONFIG_NVDIMM_PFN)
ND_PFN_ALIGN = PAGES_PER_SECTION * PAGE_SIZE,
ND_PFN_MASK = ND_PFN_ALIGN - 1,
#else
ND_PFN_ALIGN = 0,
ND_PFN_MASK = 0,
#endif
};
struct nvdimm_drvdata {
......@@ -92,8 +99,10 @@ struct nd_region {
struct device dev;
struct ida ns_ida;
struct ida btt_ida;
struct ida pfn_ida;
struct device *ns_seed;
struct device *btt_seed;
struct device *pfn_seed;
u16 ndr_mappings;
u64 ndr_size;
u64 ndr_start;
......@@ -133,6 +142,22 @@ struct nd_btt {
int id;
};
enum nd_pfn_mode {
PFN_MODE_NONE,
PFN_MODE_RAM,
PFN_MODE_PMEM,
};
struct nd_pfn {
int id;
u8 *uuid;
struct device dev;
unsigned long npfns;
enum nd_pfn_mode mode;
struct nd_pfn_sb *pfn_sb;
struct nd_namespace_common *ndns;
};
enum nd_async_mode {
ND_SYNC,
ND_ASYNC,
......@@ -159,8 +184,13 @@ int nvdimm_init_config_data(struct nvdimm_drvdata *ndd);
int nvdimm_set_config_data(struct nvdimm_drvdata *ndd, size_t offset,
void *buf, size_t len);
struct nd_btt *to_nd_btt(struct device *dev);
struct btt_sb;
u64 nd_btt_sb_checksum(struct btt_sb *btt_sb);
struct nd_gen_sb {
char reserved[SZ_4K - 8];
__le64 checksum;
};
u64 nd_sb_checksum(struct nd_gen_sb *sb);
#if IS_ENABLED(CONFIG_BTT)
int nd_btt_probe(struct nd_namespace_common *ndns, void *drvdata);
bool is_nd_btt(struct device *dev);
......@@ -180,8 +210,30 @@ static inline struct device *nd_btt_create(struct nd_region *nd_region)
{
return NULL;
}
#endif
struct nd_pfn *to_nd_pfn(struct device *dev);
#if IS_ENABLED(CONFIG_NVDIMM_PFN)
int nd_pfn_probe(struct nd_namespace_common *ndns, void *drvdata);
bool is_nd_pfn(struct device *dev);
struct device *nd_pfn_create(struct nd_region *nd_region);
#else
static inline int nd_pfn_probe(struct nd_namespace_common *ndns, void *drvdata)
{
return -ENODEV;
}
static inline bool is_nd_pfn(struct device *dev)
{
return false;
}
static inline struct device *nd_pfn_create(struct nd_region *nd_region)
{
return NULL;
}
#endif
struct nd_region *to_nd_region(struct device *dev);
int nd_region_to_nstype(struct nd_region *nd_region);
int nd_region_register_namespaces(struct nd_region *nd_region, int *err);
......
/*
* Copyright (c) 2014-2015, Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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.
*/
#ifndef __NVDIMM_PFN_H
#define __NVDIMM_PFN_H
#include <linux/types.h>
#define PFN_SIG_LEN 16
#define PFN_SIG "NVDIMM_PFN_INFO\0"
struct nd_pfn_sb {
u8 signature[PFN_SIG_LEN];
u8 uuid[16];
u8 parent_uuid[16];
__le32 flags;
__le16 version_major;
__le16 version_minor;
__le64 dataoff;
__le64 npfns;
__le32 mode;
u8 padding[4012];
__le64 checksum;
};
#endif /* __NVDIMM_PFN_H */
/*
* Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License 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.
*/
#include <linux/blkdev.h>
#include <linux/device.h>
#include <linux/genhd.h>
#include <linux/sizes.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include "nd-core.h"
#include "pfn.h"
#include "nd.h"
static