[mirror_ubuntu-artful-kernel.git] / block / blk-integrity.c

/*
 * blk-integrity.c - Block layer data integrity extensions
 *
 * Copyright (C) 2007, 2008 Oracle Corporation
 * Written by: Martin K. Petersen <martin.petersen@oracle.com>
 *
 * 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 <linux/blkdev.h>
#include <linux/mempool.h>
#include <linux/bio.h>
#include <linux/scatterlist.h>

#include "blk.h"

static struct kmem_cache *integrity_cachep;

/**
 * blk_rq_count_integrity_sg - Count number of integrity scatterlist elements
 * @rq:		request with integrity metadata attached
 *
 * Description: Returns the number of elements required in a
 * scatterlist corresponding to the integrity metadata in a request.
 */
int blk_rq_count_integrity_sg(struct request *rq)
{
	struct bio_vec *iv, *ivprv;
	struct req_iterator iter;
	unsigned int segments;

	ivprv = NULL;
	segments = 0;

	rq_for_each_integrity_segment(iv, rq, iter) {

		if (!ivprv || !BIOVEC_PHYS_MERGEABLE(ivprv, iv))
			segments++;

		ivprv = iv;
	}

	return segments;
}
EXPORT_SYMBOL(blk_rq_count_integrity_sg);

/**
 * blk_rq_map_integrity_sg - Map integrity metadata into a scatterlist
 * @rq:		request with integrity metadata attached
 * @sglist:	target scatterlist
 *
 * Description: Map the integrity vectors in request into a
 * scatterlist.  The scatterlist must be big enough to hold all
 * elements.  I.e. sized using blk_rq_count_integrity_sg().
 */
int blk_rq_map_integrity_sg(struct request *rq, struct scatterlist *sglist)
{
	struct bio_vec *iv, *ivprv;
	struct req_iterator iter;
	struct scatterlist *sg;
	unsigned int segments;

	ivprv = NULL;
	sg = NULL;
	segments = 0;

	rq_for_each_integrity_segment(iv, rq, iter) {

		if (ivprv) {
			if (!BIOVEC_PHYS_MERGEABLE(ivprv, iv))
				goto new_segment;

			sg->length += iv->bv_len;
		} else {
new_segment:
			if (!sg)
				sg = sglist;
			else {
				sg->page_link &= ~0x02;
				sg = sg_next(sg);
			}

			sg_set_page(sg, iv->bv_page, iv->bv_len, iv->bv_offset);
			segments++;
		}

		ivprv = iv;
	}

	if (sg)
		sg_mark_end(sg);

	return segments;
}
EXPORT_SYMBOL(blk_rq_map_integrity_sg);

/**
 * blk_integrity_compare - Compare integrity profile of two block devices
 * @b1:		Device to compare
 * @b2:		Device to compare
 *
 * Description: Meta-devices like DM and MD need to verify that all
 * sub-devices use the same integrity format before advertising to
 * upper layers that they can send/receive integrity metadata.  This
 * function can be used to check whether two block devices have
 * compatible integrity formats.
 */
int blk_integrity_compare(struct block_device *bd1, struct block_device *bd2)
{
	struct blk_integrity *b1 = bd1->bd_disk->integrity;
	struct blk_integrity *b2 = bd2->bd_disk->integrity;

	BUG_ON(bd1->bd_disk == NULL);
	BUG_ON(bd2->bd_disk == NULL);

	if (!b1 || !b2)
		return 0;

	if (b1->sector_size != b2->sector_size) {
		printk(KERN_ERR "%s: %s/%s sector sz %u != %u\n", __func__,
		       bd1->bd_disk->disk_name, bd2->bd_disk->disk_name,
		       b1->sector_size, b2->sector_size);
		return -1;
	}

	if (b1->tuple_size != b2->tuple_size) {
		printk(KERN_ERR "%s: %s/%s tuple sz %u != %u\n", __func__,
		       bd1->bd_disk->disk_name, bd2->bd_disk->disk_name,
		       b1->tuple_size, b2->tuple_size);
		return -1;
	}

	if (b1->tag_size && b2->tag_size && (b1->tag_size != b2->tag_size)) {
		printk(KERN_ERR "%s: %s/%s tag sz %u != %u\n", __func__,
		       bd1->bd_disk->disk_name, bd2->bd_disk->disk_name,
		       b1->tag_size, b2->tag_size);
		return -1;
	}

	if (strcmp(b1->name, b2->name)) {
		printk(KERN_ERR "%s: %s/%s type %s != %s\n", __func__,
		       bd1->bd_disk->disk_name, bd2->bd_disk->disk_name,
		       b1->name, b2->name);
		return -1;
	}

	return 0;
}
EXPORT_SYMBOL(blk_integrity_compare);

struct integrity_sysfs_entry {
	struct attribute attr;
	ssize_t (*show)(struct blk_integrity *, char *);
	ssize_t (*store)(struct blk_integrity *, const char *, size_t);
};

static ssize_t integrity_attr_show(struct kobject *kobj, struct attribute *attr,
				   char *page)
{
	struct blk_integrity *bi =
		container_of(kobj, struct blk_integrity, kobj);
	struct integrity_sysfs_entry *entry =
		container_of(attr, struct integrity_sysfs_entry, attr);

	return entry->show(bi, page);
}

static ssize_t integrity_attr_store(struct kobject *kobj, struct attribute *attr,
				    const char *page, size_t count)
{
	struct blk_integrity *bi =
		container_of(kobj, struct blk_integrity, kobj);
	struct integrity_sysfs_entry *entry =
		container_of(attr, struct integrity_sysfs_entry, attr);
	ssize_t ret = 0;

	if (entry->store)
		ret = entry->store(bi, page, count);

	return ret;
}

static ssize_t integrity_format_show(struct blk_integrity *bi, char *page)
{
	if (bi != NULL && bi->name != NULL)
		return sprintf(page, "%s\n", bi->name);
	else
		return sprintf(page, "none\n");
}

static ssize_t integrity_tag_size_show(struct blk_integrity *bi, char *page)
{
	if (bi != NULL)
		return sprintf(page, "%u\n", bi->tag_size);
	else
		return sprintf(page, "0\n");
}

static ssize_t integrity_read_store(struct blk_integrity *bi,
				    const char *page, size_t count)
{
	char *p = (char *) page;
	unsigned long val = simple_strtoul(p, &p, 10);

	if (val)
		set_bit(INTEGRITY_FLAG_READ, &bi->flags);
	else
		clear_bit(INTEGRITY_FLAG_READ, &bi->flags);

	return count;
}

static ssize_t integrity_read_show(struct blk_integrity *bi, char *page)
{
	return sprintf(page, "%d\n",
		       test_bit(INTEGRITY_FLAG_READ, &bi->flags) ? 1 : 0);
}

static ssize_t integrity_write_store(struct blk_integrity *bi,
				     const char *page, size_t count)
{
	char *p = (char *) page;
	unsigned long val = simple_strtoul(p, &p, 10);

	if (val)
		set_bit(INTEGRITY_FLAG_WRITE, &bi->flags);
	else
		clear_bit(INTEGRITY_FLAG_WRITE, &bi->flags);

	return count;
}

static ssize_t integrity_write_show(struct blk_integrity *bi, char *page)
{
	return sprintf(page, "%d\n",
		       test_bit(INTEGRITY_FLAG_WRITE, &bi->flags) ? 1 : 0);
}

static struct integrity_sysfs_entry integrity_format_entry = {
	.attr = { .name = "format", .mode = S_IRUGO },
	.show = integrity_format_show,
};

static struct integrity_sysfs_entry integrity_tag_size_entry = {
	.attr = { .name = "tag_size", .mode = S_IRUGO },
	.show = integrity_tag_size_show,
};

static struct integrity_sysfs_entry integrity_read_entry = {
	.attr = { .name = "read_verify", .mode = S_IRUGO | S_IWUSR },
	.show = integrity_read_show,
	.store = integrity_read_store,
};

static struct integrity_sysfs_entry integrity_write_entry = {
	.attr = { .name = "write_generate", .mode = S_IRUGO | S_IWUSR },
	.show = integrity_write_show,
	.store = integrity_write_store,
};

static struct attribute *integrity_attrs[] = {
	&integrity_format_entry.attr,
	&integrity_tag_size_entry.attr,
	&integrity_read_entry.attr,
	&integrity_write_entry.attr,
	NULL,
};

static struct sysfs_ops integrity_ops = {
	.show	= &integrity_attr_show,
	.store	= &integrity_attr_store,
};

static int __init blk_dev_integrity_init(void)
{
	integrity_cachep = kmem_cache_create("blkdev_integrity",
					     sizeof(struct blk_integrity),
					     0, SLAB_PANIC, NULL);
	return 0;
}
subsys_initcall(blk_dev_integrity_init);

static void blk_integrity_release(struct kobject *kobj)
{
	struct blk_integrity *bi =
		container_of(kobj, struct blk_integrity, kobj);

	kmem_cache_free(integrity_cachep, bi);
}

static struct kobj_type integrity_ktype = {
	.default_attrs	= integrity_attrs,
	.sysfs_ops	= &integrity_ops,
	.release	= blk_integrity_release,
};

/**
 * blk_integrity_register - Register a gendisk as being integrity-capable
 * @disk:	struct gendisk pointer to make integrity-aware
 * @template:	integrity profile
 *
 * Description: When a device needs to advertise itself as being able
 * to send/receive integrity metadata it must use this function to
 * register the capability with the block layer.  The template is a
 * blk_integrity struct with values appropriate for the underlying
 * hardware.  See Documentation/block/data-integrity.txt.
 */
int blk_integrity_register(struct gendisk *disk, struct blk_integrity *template)
{
	struct blk_integrity *bi;

	BUG_ON(disk == NULL);
	BUG_ON(template == NULL);

	if (disk->integrity == NULL) {
		bi = kmem_cache_alloc(integrity_cachep, GFP_KERNEL | __GFP_ZERO);
		if (!bi)
			return -1;

		if (kobject_init_and_add(&bi->kobj, &integrity_ktype,
					 &disk->dev.kobj, "%s", "integrity")) {
			kmem_cache_free(integrity_cachep, bi);
			return -1;
		}

		kobject_uevent(&bi->kobj, KOBJ_ADD);

		set_bit(INTEGRITY_FLAG_READ, &bi->flags);
		set_bit(INTEGRITY_FLAG_WRITE, &bi->flags);
		bi->sector_size = disk->queue->hardsect_size;
		disk->integrity = bi;
	} else
		bi = disk->integrity;

	/* Use the provided profile as template */
	bi->name = template->name;
	bi->generate_fn = template->generate_fn;
	bi->verify_fn = template->verify_fn;
	bi->tuple_size = template->tuple_size;
	bi->set_tag_fn = template->set_tag_fn;
	bi->get_tag_fn = template->get_tag_fn;
	bi->tag_size = template->tag_size;

	return 0;
}
EXPORT_SYMBOL(blk_integrity_register);

/**
 * blk_integrity_unregister - Remove block integrity profile
 * @disk:	disk whose integrity profile to deallocate
 *
 * Description: This function frees all memory used by the block
 * integrity profile.  To be called at device teardown.
 */
void blk_integrity_unregister(struct gendisk *disk)
{
	struct blk_integrity *bi;

	if (!disk || !disk->integrity)
		return;

	bi = disk->integrity;

	kobject_uevent(&bi->kobj, KOBJ_REMOVE);
	kobject_del(&bi->kobj);
	kobject_put(&disk->dev.kobj);
	kmem_cache_free(integrity_cachep, bi);
}
EXPORT_SYMBOL(blk_integrity_unregister);
Commit	Line	Data
7ba1ba12 MP	1	/*
	2	* blk-integrity.c - Block layer data integrity extensions
	3	*
	4	* Copyright (C) 2007, 2008 Oracle Corporation
	5	* Written by: Martin K. Petersen <martin.petersen@oracle.com>
	6	*
	7	* This program is free software; you can redistribute it and/or
	8	* modify it under the terms of the GNU General Public License version
	9	* 2 as published by the Free Software Foundation.
	10	*
	11	* This program is distributed in the hope that it will be useful, but
	12	* WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	14	* General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program; see the file COPYING. If not, write to
	18	* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
	19	* USA.
	20	*
	21	*/
	22
	23	#include <linux/blkdev.h>
	24	#include <linux/mempool.h>
	25	#include <linux/bio.h>
	26	#include <linux/scatterlist.h>
	27
	28	#include "blk.h"
	29
	30	static struct kmem_cache *integrity_cachep;
	31
	32	/**
	33	* blk_rq_count_integrity_sg - Count number of integrity scatterlist elements
	34	* @rq: request with integrity metadata attached
	35	*
	36	* Description: Returns the number of elements required in a
	37	* scatterlist corresponding to the integrity metadata in a request.
	38	*/
	39	int blk_rq_count_integrity_sg(struct request *rq)
	40	{
	41	struct bio_vec iv, ivprv;
	42	struct req_iterator iter;
	43	unsigned int segments;
	44
	45	ivprv = NULL;
	46	segments = 0;
	47
	48	rq_for_each_integrity_segment(iv, rq, iter) {
	49
	50	if (!ivprv \|\| !BIOVEC_PHYS_MERGEABLE(ivprv, iv))
	51	segments++;
	52
	53	ivprv = iv;
	54	}
	55
	56	return segments;
	57	}
	58	EXPORT_SYMBOL(blk_rq_count_integrity_sg);
	59
	60	/**
	61	* blk_rq_map_integrity_sg - Map integrity metadata into a scatterlist
	62	* @rq: request with integrity metadata attached
	63	* @sglist: target scatterlist
	64	*
65	* Description: Map the integrity vectors in request into a
66	* scatterlist. The scatterlist must be big enough to hold all
67	* elements. I.e. sized using blk_rq_count_integrity_sg().
68	*/
69	int blk_rq_map_integrity_sg(struct request rq, struct scatterlist sglist)
70	{
71	struct bio_vec iv, ivprv;
72	struct req_iterator iter;
73	struct scatterlist *sg;
74	unsigned int segments;
75
76	ivprv = NULL;
77	sg = NULL;
78	segments = 0;
79
80	rq_for_each_integrity_segment(iv, rq, iter) {
81
82	if (ivprv) {
83	if (!BIOVEC_PHYS_MERGEABLE(ivprv, iv))
84	goto new_segment;
85
86	sg->length += iv->bv_len;
87	} else {
88	new_segment:
89	if (!sg)
90	sg = sglist;
91	else {
92	sg->page_link &= ~0x02;
93	sg = sg_next(sg);
94	}
95
96	sg_set_page(sg, iv->bv_page, iv->bv_len, iv->bv_offset);
97	segments++;
98	}
99
100	ivprv = iv;
101	}
102
103	if (sg)
104	sg_mark_end(sg);
105
106	return segments;
107	}
108	EXPORT_SYMBOL(blk_rq_map_integrity_sg);
109
110	/**
111	* blk_integrity_compare - Compare integrity profile of two block devices
112	* @b1: Device to compare
113	* @b2: Device to compare
114	*
115	* Description: Meta-devices like DM and MD need to verify that all
116	* sub-devices use the same integrity format before advertising to
117	* upper layers that they can send/receive integrity metadata. This
118	* function can be used to check whether two block devices have
119	* compatible integrity formats.
120	*/
121	int blk_integrity_compare(struct block_device bd1, struct block_device bd2)
122	{
123	struct blk_integrity *b1 = bd1->bd_disk->integrity;
124	struct blk_integrity *b2 = bd2->bd_disk->integrity;
125
126	BUG_ON(bd1->bd_disk == NULL);
127	BUG_ON(bd2->bd_disk == NULL);
128
129	if (!b1 \|\| !b2)
130	return 0;
131
132	if (b1->sector_size != b2->sector_size) {
133	printk(KERN_ERR "%s: %s/%s sector sz %u != %u\n", __func__,
134	bd1->bd_disk->disk_name, bd2->bd_disk->disk_name,
135	b1->sector_size, b2->sector_size);
136	return -1;
137	}
138
139	if (b1->tuple_size != b2->tuple_size) {
140	printk(KERN_ERR "%s: %s/%s tuple sz %u != %u\n", __func__,
141	bd1->bd_disk->disk_name, bd2->bd_disk->disk_name,
142	b1->tuple_size, b2->tuple_size);
143	return -1;
144	}
145
146	if (b1->tag_size && b2->tag_size && (b1->tag_size != b2->tag_size)) {
147	printk(KERN_ERR "%s: %s/%s tag sz %u != %u\n", __func__,
148	bd1->bd_disk->disk_name, bd2->bd_disk->disk_name,
149	b1->tag_size, b2->tag_size);
150	return -1;
151	}
152
153	if (strcmp(b1->name, b2->name)) {
154	printk(KERN_ERR "%s: %s/%s type %s != %s\n", __func__,
155	bd1->bd_disk->disk_name, bd2->bd_disk->disk_name,
156	b1->name, b2->name);
157	return -1;
158	}
159
160	return 0;
161	}
162	EXPORT_SYMBOL(blk_integrity_compare);
163
164	struct integrity_sysfs_entry {
165	struct attribute attr;
166	ssize_t (show)(struct blk_integrity , char *);
167	ssize_t (store)(struct blk_integrity , const char *, size_t);
168	};
169
170	static ssize_t integrity_attr_show(struct kobject kobj, struct attribute attr,
171	char *page)
172	{
173	struct blk_integrity *bi =
174	container_of(kobj, struct blk_integrity, kobj);
175	struct integrity_sysfs_entry *entry =
176	container_of(attr, struct integrity_sysfs_entry, attr);
177
178	return entry->show(bi, page);
179	}
180
181	static ssize_t integrity_attr_store(struct kobject kobj, struct attribute attr,
182	const char *page, size_t count)
183	{
184	struct blk_integrity *bi =
185	container_of(kobj, struct blk_integrity, kobj);
186	struct integrity_sysfs_entry *entry =
187	container_of(attr, struct integrity_sysfs_entry, attr);
188	ssize_t ret = 0;
189
190	if (entry->store)
191	ret = entry->store(bi, page, count);
192
193	return ret;
194	}
195
196	static ssize_t integrity_format_show(struct blk_integrity bi, char page)
197	{
198	if (bi != NULL && bi->name != NULL)
199	return sprintf(page, "%s\n", bi->name);
200	else
201	return sprintf(page, "none\n");
202	}
203
204	static ssize_t integrity_tag_size_show(struct blk_integrity bi, char page)
205	{
206	if (bi != NULL)
207	return sprintf(page, "%u\n", bi->tag_size);
208	else
209	return sprintf(page, "0\n");
210	}
211
212	static ssize_t integrity_read_store(struct blk_integrity *bi,
213	const char *page, size_t count)
214	{
215	char p = (char ) page;
216	unsigned long val = simple_strtoul(p, &p, 10);
217
218	if (val)
219	set_bit(INTEGRITY_FLAG_READ, &bi->flags);
220	else
221	clear_bit(INTEGRITY_FLAG_READ, &bi->flags);
222
223	return count;
224	}
225
226	static ssize_t integrity_read_show(struct blk_integrity bi, char page)
227	{
228	return sprintf(page, "%d\n",
229	test_bit(INTEGRITY_FLAG_READ, &bi->flags) ? 1 : 0);
230	}
231
232	static ssize_t integrity_write_store(struct blk_integrity *bi,
233	const char *page, size_t count)
234	{
235	char p = (char ) page;
236	unsigned long val = simple_strtoul(p, &p, 10);
237
238	if (val)
239	set_bit(INTEGRITY_FLAG_WRITE, &bi->flags);
240	else
241	clear_bit(INTEGRITY_FLAG_WRITE, &bi->flags);
242
243	return count;
244	}
245
246	static ssize_t integrity_write_show(struct blk_integrity bi, char page)
247	{
248	return sprintf(page, "%d\n",
249	test_bit(INTEGRITY_FLAG_WRITE, &bi->flags) ? 1 : 0);
250	}
251
252	static struct integrity_sysfs_entry integrity_format_entry = {
253	.attr = { .name = "format", .mode = S_IRUGO },
254	.show = integrity_format_show,
255	};
256
257	static struct integrity_sysfs_entry integrity_tag_size_entry = {
258	.attr = { .name = "tag_size", .mode = S_IRUGO },
259	.show = integrity_tag_size_show,
260	};
261
262	static struct integrity_sysfs_entry integrity_read_entry = {
263	.attr = { .name = "read_verify", .mode = S_IRUGO \| S_IWUSR },
264	.show = integrity_read_show,
265	.store = integrity_read_store,
266	};
267
268	static struct integrity_sysfs_entry integrity_write_entry = {
269	.attr = { .name = "write_generate", .mode = S_IRUGO \| S_IWUSR },
270	.show = integrity_write_show,
271	.store = integrity_write_store,
272	};
273
274	static struct attribute *integrity_attrs[] = {
275	&integrity_format_entry.attr,
276	&integrity_tag_size_entry.attr,
277	&integrity_read_entry.attr,
278	&integrity_write_entry.attr,
279	NULL,
280	};
281
282	static struct sysfs_ops integrity_ops = {
283	.show = &integrity_attr_show,
284	.store = &integrity_attr_store,
285	};
286
287	static int __init blk_dev_integrity_init(void)
288	{
289	integrity_cachep = kmem_cache_create("blkdev_integrity",
290	sizeof(struct blk_integrity),
291	0, SLAB_PANIC, NULL);
292	return 0;
293	}
294	subsys_initcall(blk_dev_integrity_init);
295
296	static void blk_integrity_release(struct kobject *kobj)
297	{
298	struct blk_integrity *bi =
299	container_of(kobj, struct blk_integrity, kobj);
300
301	kmem_cache_free(integrity_cachep, bi);
302	}
303
304	static struct kobj_type integrity_ktype = {
305	.default_attrs = integrity_attrs,
306	.sysfs_ops = &integrity_ops,
307	.release = blk_integrity_release,
308	};
309
310	/**
311	* blk_integrity_register - Register a gendisk as being integrity-capable
312	* @disk: struct gendisk pointer to make integrity-aware
313	* @template: integrity profile
314	*
315	* Description: When a device needs to advertise itself as being able
316	* to send/receive integrity metadata it must use this function to
317	* register the capability with the block layer. The template is a
318	* blk_integrity struct with values appropriate for the underlying
319	* hardware. See Documentation/block/data-integrity.txt.
320	*/
321	int blk_integrity_register(struct gendisk disk, struct blk_integrity template)
322	{
323	struct blk_integrity *bi;
324
325	BUG_ON(disk == NULL);
326	BUG_ON(template == NULL);
327
328	if (disk->integrity == NULL) {
329	bi = kmem_cache_alloc(integrity_cachep, GFP_KERNEL \| __GFP_ZERO);
330	if (!bi)
331	return -1;
332
333	if (kobject_init_and_add(&bi->kobj, &integrity_ktype,
334	&disk->dev.kobj, "%s", "integrity")) {
335	kmem_cache_free(integrity_cachep, bi);
336	return -1;
337	}
338
339	kobject_uevent(&bi->kobj, KOBJ_ADD);
340
341	set_bit(INTEGRITY_FLAG_READ, &bi->flags);
342	set_bit(INTEGRITY_FLAG_WRITE, &bi->flags);
343	bi->sector_size = disk->queue->hardsect_size;
344	disk->integrity = bi;
345	} else
346	bi = disk->integrity;
347
348	/* Use the provided profile as template */
349	bi->name = template->name;
350	bi->generate_fn = template->generate_fn;
351	bi->verify_fn = template->verify_fn;
352	bi->tuple_size = template->tuple_size;
353	bi->set_tag_fn = template->set_tag_fn;
354	bi->get_tag_fn = template->get_tag_fn;
355	bi->tag_size = template->tag_size;
356
357	return 0;
358	}
359	EXPORT_SYMBOL(blk_integrity_register);
360
361	/**
362	* blk_integrity_unregister - Remove block integrity profile
363	* @disk: disk whose integrity profile to deallocate
364	*
365	* Description: This function frees all memory used by the block
366	* integrity profile. To be called at device teardown.
367	*/
368	void blk_integrity_unregister(struct gendisk *disk)
369	{
370	struct blk_integrity *bi;
371
372	if (!disk \|\| !disk->integrity)
373	return;
374
375	bi = disk->integrity;
376
377	kobject_uevent(&bi->kobj, KOBJ_REMOVE);
378	kobject_del(&bi->kobj);
379	kobject_put(&disk->dev.kobj);
380	kmem_cache_free(integrity_cachep, bi);
381	}
382	EXPORT_SYMBOL(blk_integrity_unregister);