[linux-2.6-block.git] / drivers / nvdimm / pfn_devs.c

/*
 * 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 void nd_pfn_release(struct device *dev)
{
	struct nd_region *nd_region = to_nd_region(dev->parent);
	struct nd_pfn *nd_pfn = to_nd_pfn(dev);

	dev_dbg(dev, "%s\n", __func__);
	nd_detach_ndns(&nd_pfn->dev, &nd_pfn->ndns);
	ida_simple_remove(&nd_region->pfn_ida, nd_pfn->id);
	kfree(nd_pfn->uuid);
	kfree(nd_pfn);
}

static struct device_type nd_pfn_device_type = {
	.name = "nd_pfn",
	.release = nd_pfn_release,
};

bool is_nd_pfn(struct device *dev)
{
	return dev ? dev->type == &nd_pfn_device_type : false;
}
EXPORT_SYMBOL(is_nd_pfn);

struct nd_pfn *to_nd_pfn(struct device *dev)
{
	struct nd_pfn *nd_pfn = container_of(dev, struct nd_pfn, dev);

	WARN_ON(!is_nd_pfn(dev));
	return nd_pfn;
}
EXPORT_SYMBOL(to_nd_pfn);

static ssize_t mode_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct nd_pfn *nd_pfn = to_nd_pfn(dev);

	switch (nd_pfn->mode) {
	case PFN_MODE_RAM:
		return sprintf(buf, "ram\n");
	case PFN_MODE_PMEM:
		return sprintf(buf, "pmem\n");
	default:
		return sprintf(buf, "none\n");
	}
}

static ssize_t mode_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t len)
{
	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
	ssize_t rc = 0;

	device_lock(dev);
	nvdimm_bus_lock(dev);
	if (dev->driver)
		rc = -EBUSY;
	else {
		size_t n = len - 1;

		if (strncmp(buf, "pmem\n", n) == 0
				|| strncmp(buf, "pmem", n) == 0) {
			/* TODO: allocate from PMEM support */
			rc = -ENOTTY;
		} else if (strncmp(buf, "ram\n", n) == 0
				|| strncmp(buf, "ram", n) == 0)
			nd_pfn->mode = PFN_MODE_RAM;
		else if (strncmp(buf, "none\n", n) == 0
				|| strncmp(buf, "none", n) == 0)
			nd_pfn->mode = PFN_MODE_NONE;
		else
			rc = -EINVAL;
	}
	dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
			rc, buf, buf[len - 1] == '\n' ? "" : "\n");
	nvdimm_bus_unlock(dev);
	device_unlock(dev);

	return rc ? rc : len;
}
static DEVICE_ATTR_RW(mode);

static ssize_t uuid_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct nd_pfn *nd_pfn = to_nd_pfn(dev);

	if (nd_pfn->uuid)
		return sprintf(buf, "%pUb\n", nd_pfn->uuid);
	return sprintf(buf, "\n");
}

static ssize_t uuid_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t len)
{
	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
	ssize_t rc;

	device_lock(dev);
	rc = nd_uuid_store(dev, &nd_pfn->uuid, buf, len);
	dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
			rc, buf, buf[len - 1] == '\n' ? "" : "\n");
	device_unlock(dev);

	return rc ? rc : len;
}
static DEVICE_ATTR_RW(uuid);

static ssize_t namespace_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
	ssize_t rc;

	nvdimm_bus_lock(dev);
	rc = sprintf(buf, "%s\n", nd_pfn->ndns
			? dev_name(&nd_pfn->ndns->dev) : "");
	nvdimm_bus_unlock(dev);
	return rc;
}

static ssize_t namespace_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t len)
{
	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
	ssize_t rc;

	device_lock(dev);
	nvdimm_bus_lock(dev);
	rc = nd_namespace_store(dev, &nd_pfn->ndns, buf, len);
	dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
			rc, buf, buf[len - 1] == '\n' ? "" : "\n");
	nvdimm_bus_unlock(dev);
	device_unlock(dev);

	return rc;
}
static DEVICE_ATTR_RW(namespace);

static struct attribute *nd_pfn_attributes[] = {
	&dev_attr_mode.attr,
	&dev_attr_namespace.attr,
	&dev_attr_uuid.attr,
	NULL,
};

static struct attribute_group nd_pfn_attribute_group = {
	.attrs = nd_pfn_attributes,
};

static const struct attribute_group *nd_pfn_attribute_groups[] = {
	&nd_pfn_attribute_group,
	&nd_device_attribute_group,
	&nd_numa_attribute_group,
	NULL,
};

static struct device *__nd_pfn_create(struct nd_region *nd_region,
		u8 *uuid, enum nd_pfn_mode mode,
		struct nd_namespace_common *ndns)
{
	struct nd_pfn *nd_pfn;
	struct device *dev;

	/* we can only create pages for contiguous ranged of pmem */
	if (!is_nd_pmem(&nd_region->dev))
		return NULL;

	nd_pfn = kzalloc(sizeof(*nd_pfn), GFP_KERNEL);
	if (!nd_pfn)
		return NULL;

	nd_pfn->id = ida_simple_get(&nd_region->pfn_ida, 0, 0, GFP_KERNEL);
	if (nd_pfn->id < 0) {
		kfree(nd_pfn);
		return NULL;
	}

	nd_pfn->mode = mode;
	if (uuid)
		uuid = kmemdup(uuid, 16, GFP_KERNEL);
	nd_pfn->uuid = uuid;
	dev = &nd_pfn->dev;
	dev_set_name(dev, "pfn%d.%d", nd_region->id, nd_pfn->id);
	dev->parent = &nd_region->dev;
	dev->type = &nd_pfn_device_type;
	dev->groups = nd_pfn_attribute_groups;
	device_initialize(&nd_pfn->dev);
	if (ndns && !__nd_attach_ndns(&nd_pfn->dev, ndns, &nd_pfn->ndns)) {
		dev_dbg(&ndns->dev, "%s failed, already claimed by %s\n",
				__func__, dev_name(ndns->claim));
		put_device(dev);
		return NULL;
	}
	return dev;
}

struct device *nd_pfn_create(struct nd_region *nd_region)
{
	struct device *dev = __nd_pfn_create(nd_region, NULL, PFN_MODE_NONE,
			NULL);

	if (dev)
		__nd_device_register(dev);
	return dev;
}

int nd_pfn_validate(struct nd_pfn *nd_pfn)
{
	struct nd_namespace_common *ndns = nd_pfn->ndns;
	struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
	struct nd_namespace_io *nsio;
	u64 checksum, offset;

	if (!pfn_sb || !ndns)
		return -ENODEV;

	if (!is_nd_pmem(nd_pfn->dev.parent))
		return -ENODEV;

	/* section alignment for simple hotplug */
	if (nvdimm_namespace_capacity(ndns) < ND_PFN_ALIGN)
		return -ENODEV;

	if (nvdimm_read_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb)))
		return -ENXIO;

	if (memcmp(pfn_sb->signature, PFN_SIG, PFN_SIG_LEN) != 0)
		return -ENODEV;

	checksum = le64_to_cpu(pfn_sb->checksum);
	pfn_sb->checksum = 0;
	if (checksum != nd_sb_checksum((struct nd_gen_sb *) pfn_sb))
		return -ENODEV;
	pfn_sb->checksum = cpu_to_le64(checksum);

	switch (le32_to_cpu(pfn_sb->mode)) {
	case PFN_MODE_RAM:
		break;
	case PFN_MODE_PMEM:
		/* TODO: allocate from PMEM support */
		return -ENOTTY;
	default:
		return -ENXIO;
	}

	if (!nd_pfn->uuid) {
		/* from probe we allocate */
		nd_pfn->uuid = kmemdup(pfn_sb->uuid, 16, GFP_KERNEL);
		if (!nd_pfn->uuid)
			return -ENOMEM;
	} else {
		/* from init we validate */
		if (memcmp(nd_pfn->uuid, pfn_sb->uuid, 16) != 0)
			return -EINVAL;
	}

	/*
	 * These warnings are verbose because they can only trigger in
	 * the case where the physical address alignment of the
	 * namespace has changed since the pfn superblock was
	 * established.
	 */
	offset = le64_to_cpu(pfn_sb->dataoff);
	nsio = to_nd_namespace_io(&ndns->dev);
	if (nsio->res.start & ND_PFN_MASK) {
		dev_err(&nd_pfn->dev,
				"init failed: %s not section aligned\n",
				dev_name(&ndns->dev));
		return -EBUSY;
	} else if (offset >= resource_size(&nsio->res)) {
		dev_err(&nd_pfn->dev, "pfn array size exceeds capacity of %s\n",
				dev_name(&ndns->dev));
		return -EBUSY;
	}

	return 0;
}
EXPORT_SYMBOL(nd_pfn_validate);

int nd_pfn_probe(struct nd_namespace_common *ndns, void *drvdata)
{
	int rc;
	struct device *dev;
	struct nd_pfn *nd_pfn;
	struct nd_pfn_sb *pfn_sb;
	struct nd_region *nd_region = to_nd_region(ndns->dev.parent);

	if (ndns->force_raw)
		return -ENODEV;

	nvdimm_bus_lock(&ndns->dev);
	dev = __nd_pfn_create(nd_region, NULL, PFN_MODE_NONE, ndns);
	nvdimm_bus_unlock(&ndns->dev);
	if (!dev)
		return -ENOMEM;
	dev_set_drvdata(dev, drvdata);
	pfn_sb = kzalloc(sizeof(*pfn_sb), GFP_KERNEL);
	nd_pfn = to_nd_pfn(dev);
	nd_pfn->pfn_sb = pfn_sb;
	rc = nd_pfn_validate(nd_pfn);
	nd_pfn->pfn_sb = NULL;
	kfree(pfn_sb);
	dev_dbg(&ndns->dev, "%s: pfn: %s\n", __func__,
			rc == 0 ? dev_name(dev) : "<none>");
	if (rc < 0) {
		__nd_detach_ndns(dev, &nd_pfn->ndns);
		put_device(dev);
	} else
		__nd_device_register(&nd_pfn->dev);

	return rc;
}
EXPORT_SYMBOL(nd_pfn_probe);
Commit	Line	Data
e1455744 DW	1	/*
	2	* Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of version 2 of the GNU General Public License as
	6	* published by the Free Software Foundation.
	7	*
	8	* This program is distributed in the hope that it will be useful, but
	9	* WITHOUT ANY WARRANTY; without even the implied warranty of
	10	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	11	* General Public License for more details.
	12	*/
	13	#include <linux/blkdev.h>
	14	#include <linux/device.h>
	15	#include <linux/genhd.h>
	16	#include <linux/sizes.h>
	17	#include <linux/slab.h>
	18	#include <linux/fs.h>
	19	#include <linux/mm.h>
	20	#include "nd-core.h"
	21	#include "pfn.h"
	22	#include "nd.h"
	23
	24	static void nd_pfn_release(struct device *dev)
	25	{
	26	struct nd_region *nd_region = to_nd_region(dev->parent);
	27	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
	28
	29	dev_dbg(dev, "%s\n", __func__);
	30	nd_detach_ndns(&nd_pfn->dev, &nd_pfn->ndns);
	31	ida_simple_remove(&nd_region->pfn_ida, nd_pfn->id);
	32	kfree(nd_pfn->uuid);
	33	kfree(nd_pfn);
	34	}
	35
	36	static struct device_type nd_pfn_device_type = {
	37	.name = "nd_pfn",
	38	.release = nd_pfn_release,
	39	};
	40
	41	bool is_nd_pfn(struct device *dev)
	42	{
	43	return dev ? dev->type == &nd_pfn_device_type : false;
	44	}
	45	EXPORT_SYMBOL(is_nd_pfn);
	46
	47	struct nd_pfn to_nd_pfn(struct device dev)
	48	{
	49	struct nd_pfn *nd_pfn = container_of(dev, struct nd_pfn, dev);
	50
	51	WARN_ON(!is_nd_pfn(dev));
	52	return nd_pfn;
	53	}
	54	EXPORT_SYMBOL(to_nd_pfn);
	55
	56	static ssize_t mode_show(struct device *dev,
	57	struct device_attribute attr, char buf)
	58	{
	59	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
	60
	61	switch (nd_pfn->mode) {
	62	case PFN_MODE_RAM:
	63	return sprintf(buf, "ram\n");
	64	case PFN_MODE_PMEM:
65	return sprintf(buf, "pmem\n");
66	default:
67	return sprintf(buf, "none\n");
68	}
69	}
70
71	static ssize_t mode_store(struct device *dev,
72	struct device_attribute attr, const char buf, size_t len)
73	{
74	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
75	ssize_t rc = 0;
76
77	device_lock(dev);
78	nvdimm_bus_lock(dev);
79	if (dev->driver)
80	rc = -EBUSY;
81	else {
82	size_t n = len - 1;
83
84	if (strncmp(buf, "pmem\n", n) == 0
85	\|\| strncmp(buf, "pmem", n) == 0) {
86	/* TODO: allocate from PMEM support */
87	rc = -ENOTTY;
88	} else if (strncmp(buf, "ram\n", n) == 0
89	\|\| strncmp(buf, "ram", n) == 0)
90	nd_pfn->mode = PFN_MODE_RAM;
91	else if (strncmp(buf, "none\n", n) == 0
92	\|\| strncmp(buf, "none", n) == 0)
93	nd_pfn->mode = PFN_MODE_NONE;
94	else
95	rc = -EINVAL;
96	}
97	dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
98	rc, buf, buf[len - 1] == '\n' ? "" : "\n");
99	nvdimm_bus_unlock(dev);
100	device_unlock(dev);
101
102	return rc ? rc : len;
103	}
104	static DEVICE_ATTR_RW(mode);
105
106	static ssize_t uuid_show(struct device *dev,
107	struct device_attribute attr, char buf)
108	{
109	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
110
111	if (nd_pfn->uuid)
112	return sprintf(buf, "%pUb\n", nd_pfn->uuid);
113	return sprintf(buf, "\n");
114	}
115
116	static ssize_t uuid_store(struct device *dev,
117	struct device_attribute attr, const char buf, size_t len)
118	{
119	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
120	ssize_t rc;
121
122	device_lock(dev);
123	rc = nd_uuid_store(dev, &nd_pfn->uuid, buf, len);
124	dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
125	rc, buf, buf[len - 1] == '\n' ? "" : "\n");
126	device_unlock(dev);
127
128	return rc ? rc : len;
129	}
130	static DEVICE_ATTR_RW(uuid);
131
132	static ssize_t namespace_show(struct device *dev,
133	struct device_attribute attr, char buf)
134	{
135	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
136	ssize_t rc;
137
138	nvdimm_bus_lock(dev);
139	rc = sprintf(buf, "%s\n", nd_pfn->ndns
140	? dev_name(&nd_pfn->ndns->dev) : "");
141	nvdimm_bus_unlock(dev);
142	return rc;
143	}
144
145	static ssize_t namespace_store(struct device *dev,
146	struct device_attribute attr, const char buf, size_t len)
147	{
148	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
149	ssize_t rc;
150
e1455744	151	device_lock(dev);
4ca8b57a	152	nvdimm_bus_lock(dev);
e1455744 DW	153	rc = nd_namespace_store(dev, &nd_pfn->ndns, buf, len);
	154	dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
	155	rc, buf, buf[len - 1] == '\n' ? "" : "\n");
e1455744	156	nvdimm_bus_unlock(dev);
4ca8b57a	157	device_unlock(dev);
e1455744 DW	158
	159	return rc;
	160	}
	161	static DEVICE_ATTR_RW(namespace);
	162
	163	static struct attribute *nd_pfn_attributes[] = {
	164	&dev_attr_mode.attr,
	165	&dev_attr_namespace.attr,
	166	&dev_attr_uuid.attr,
	167	NULL,
	168	};
	169
	170	static struct attribute_group nd_pfn_attribute_group = {
	171	.attrs = nd_pfn_attributes,
	172	};
	173
	174	static const struct attribute_group *nd_pfn_attribute_groups[] = {
	175	&nd_pfn_attribute_group,
	176	&nd_device_attribute_group,
	177	&nd_numa_attribute_group,
	178	NULL,
	179	};
	180
	181	static struct device __nd_pfn_create(struct nd_region nd_region,
	182	u8 *uuid, enum nd_pfn_mode mode,
	183	struct nd_namespace_common *ndns)
	184	{
	185	struct nd_pfn *nd_pfn;
	186	struct device *dev;
	187
	188	/* we can only create pages for contiguous ranged of pmem */
	189	if (!is_nd_pmem(&nd_region->dev))
	190	return NULL;
	191
	192	nd_pfn = kzalloc(sizeof(*nd_pfn), GFP_KERNEL);
	193	if (!nd_pfn)
	194	return NULL;
	195
	196	nd_pfn->id = ida_simple_get(&nd_region->pfn_ida, 0, 0, GFP_KERNEL);
	197	if (nd_pfn->id < 0) {
	198	kfree(nd_pfn);
	199	return NULL;
	200	}
	201
	202	nd_pfn->mode = mode;
	203	if (uuid)
	204	uuid = kmemdup(uuid, 16, GFP_KERNEL);
	205	nd_pfn->uuid = uuid;
	206	dev = &nd_pfn->dev;
	207	dev_set_name(dev, "pfn%d.%d", nd_region->id, nd_pfn->id);
	208	dev->parent = &nd_region->dev;
	209	dev->type = &nd_pfn_device_type;
	210	dev->groups = nd_pfn_attribute_groups;
	211	device_initialize(&nd_pfn->dev);
	212	if (ndns && !__nd_attach_ndns(&nd_pfn->dev, ndns, &nd_pfn->ndns)) {
	213	dev_dbg(&ndns->dev, "%s failed, already claimed by %s\n",
	214	__func__, dev_name(ndns->claim));
	215	put_device(dev);
	216	return NULL;
	217	}
	218	return dev;
	219	}
	220
	221	struct device nd_pfn_create(struct nd_region nd_region)
222	{
223	struct device *dev = __nd_pfn_create(nd_region, NULL, PFN_MODE_NONE,
224	NULL);
225
226	if (dev)
227	__nd_device_register(dev);
228	return dev;
229	}
230
32ab0a3f	231	int nd_pfn_validate(struct nd_pfn *nd_pfn)
e1455744 DW	232	{
	233	struct nd_namespace_common *ndns = nd_pfn->ndns;
	234	struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
	235	struct nd_namespace_io *nsio;
	236	u64 checksum, offset;
	237
	238	if (!pfn_sb \|\| !ndns)
	239	return -ENODEV;
	240
	241	if (!is_nd_pmem(nd_pfn->dev.parent))
	242	return -ENODEV;
	243
	244	/* section alignment for simple hotplug */
	245	if (nvdimm_namespace_capacity(ndns) < ND_PFN_ALIGN)
	246	return -ENODEV;
	247
	248	if (nvdimm_read_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb)))
	249	return -ENXIO;
	250
	251	if (memcmp(pfn_sb->signature, PFN_SIG, PFN_SIG_LEN) != 0)
	252	return -ENODEV;
	253
	254	checksum = le64_to_cpu(pfn_sb->checksum);
	255	pfn_sb->checksum = 0;
	256	if (checksum != nd_sb_checksum((struct nd_gen_sb *) pfn_sb))
	257	return -ENODEV;
	258	pfn_sb->checksum = cpu_to_le64(checksum);
	259
	260	switch (le32_to_cpu(pfn_sb->mode)) {
	261	case PFN_MODE_RAM:
	262	break;
	263	case PFN_MODE_PMEM:
	264	/* TODO: allocate from PMEM support */
	265	return -ENOTTY;
	266	default:
	267	return -ENXIO;
	268	}
	269
	270	if (!nd_pfn->uuid) {
	271	/* from probe we allocate */
	272	nd_pfn->uuid = kmemdup(pfn_sb->uuid, 16, GFP_KERNEL);
	273	if (!nd_pfn->uuid)
	274	return -ENOMEM;
	275	} else {
	276	/* from init we validate */
	277	if (memcmp(nd_pfn->uuid, pfn_sb->uuid, 16) != 0)
	278	return -EINVAL;
	279	}
	280
	281	/*
	282	* These warnings are verbose because they can only trigger in
	283	* the case where the physical address alignment of the
	284	* namespace has changed since the pfn superblock was
	285	* established.
	286	*/
	287	offset = le64_to_cpu(pfn_sb->dataoff);
	288	nsio = to_nd_namespace_io(&ndns->dev);
32ab0a3f	289	if (nsio->res.start & ND_PFN_MASK) {
e1455744	290	dev_err(&nd_pfn->dev,
32ab0a3f DW	291	"init failed: %s not section aligned\n",
32ab0a3f DW	292	dev_name(&ndns->dev));
e1455744 DW	293	return -EBUSY;
	294	} else if (offset >= resource_size(&nsio->res)) {
	295	dev_err(&nd_pfn->dev, "pfn array size exceeds capacity of %s\n",
	296	dev_name(&ndns->dev));
	297	return -EBUSY;
	298	}
	299
	300	return 0;
	301	}
32ab0a3f	302	EXPORT_SYMBOL(nd_pfn_validate);
e1455744 DW	303
	304	int nd_pfn_probe(struct nd_namespace_common ndns, void drvdata)
	305	{
	306	int rc;
	307	struct device *dev;
	308	struct nd_pfn *nd_pfn;
	309	struct nd_pfn_sb *pfn_sb;
	310	struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
	311
	312	if (ndns->force_raw)
	313	return -ENODEV;
	314
	315	nvdimm_bus_lock(&ndns->dev);
	316	dev = __nd_pfn_create(nd_region, NULL, PFN_MODE_NONE, ndns);
	317	nvdimm_bus_unlock(&ndns->dev);
	318	if (!dev)
	319	return -ENOMEM;
	320	dev_set_drvdata(dev, drvdata);
	321	pfn_sb = kzalloc(sizeof(*pfn_sb), GFP_KERNEL);
	322	nd_pfn = to_nd_pfn(dev);
	323	nd_pfn->pfn_sb = pfn_sb;
	324	rc = nd_pfn_validate(nd_pfn);
	325	nd_pfn->pfn_sb = NULL;
	326	kfree(pfn_sb);
	327	dev_dbg(&ndns->dev, "%s: pfn: %s\n", __func__,
	328	rc == 0 ? dev_name(dev) : "<none>");
	329	if (rc < 0) {
	330	__nd_detach_ndns(dev, &nd_pfn->ndns);
	331	put_device(dev);
	332	} else
	333	__nd_device_register(&nd_pfn->dev);
	334
	335	return rc;
	336	}
	337	EXPORT_SYMBOL(nd_pfn_probe);