[net-next-2.6.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 <linux/slab.h>

#include "blk.h"

static struct kmem_cache *integrity_cachep;

/**
 * blk_rq_count_integrity_sg - Count number of integrity scatterlist elements
 * @q:		request queue
 * @bio:	bio with integrity metadata attached
 *
 * Description: Returns the number of elements required in a
 * scatterlist corresponding to the integrity metadata in a bio.
 */
int blk_rq_count_integrity_sg(struct request_queue *q, struct bio *bio)
{
	struct bio_vec *iv, *ivprv = NULL;
	unsigned int segments = 0;
	unsigned int seg_size = 0;
	unsigned int i = 0;

	bio_for_each_integrity_vec(iv, bio, i) {

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

			if (!BIOVEC_SEG_BOUNDARY(q, ivprv, iv))
				goto new_segment;

			if (seg_size + iv->bv_len > queue_max_segment_size(q))
				goto new_segment;

			seg_size += iv->bv_len;
		} else {
new_segment:
			segments++;
			seg_size = iv->bv_len;
		}

		ivprv = iv;
	}

	return segments;
}
EXPORT_SYMBOL(blk_rq_count_integrity_sg);

/**
 * blk_rq_map_integrity_sg - Map integrity metadata into a scatterlist
 * @q:		request queue
 * @bio:	bio 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_queue *q, struct bio *bio,
			    struct scatterlist *sglist)
{
	struct bio_vec *iv, *ivprv = NULL;
	struct scatterlist *sg = NULL;
	unsigned int segments = 0;
	unsigned int i = 0;

	bio_for_each_integrity_vec(iv, bio, i) {

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

			if (!BIOVEC_SEG_BOUNDARY(q, ivprv, iv))
				goto new_segment;

			if (sg->length + iv->bv_len > queue_max_segment_size(q))
				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 disks
 * @gd1:	Disk to compare
 * @gd2:	Disk 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 gendisk devices have
 * compatible integrity formats.
 */
int blk_integrity_compare(struct gendisk *gd1, struct gendisk *gd2)
{
	struct blk_integrity *b1 = gd1->integrity;
	struct blk_integrity *b2 = gd2->integrity;

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

	if (!b1 || !b2)
		return -1;

	if (b1->sector_size != b2->sector_size) {
		printk(KERN_ERR "%s: %s/%s sector sz %u != %u\n", __func__,
		       gd1->disk_name, gd2->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__,
		       gd1->disk_name, gd2->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__,
		       gd1->disk_name, gd2->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__,
		       gd1->disk_name, gd2->disk_name,
		       b1->name, b2->name);
		return -1;
	}

	return 0;
}
EXPORT_SYMBOL(blk_integrity_compare);

int blk_integrity_merge_rq(struct request_queue *q, struct request *req,
			   struct request *next)
{
	if (blk_integrity_rq(req) != blk_integrity_rq(next))
		return -1;

	if (req->nr_integrity_segments + next->nr_integrity_segments >
	    q->limits.max_integrity_segments)
		return -1;

	return 0;
}
EXPORT_SYMBOL(blk_integrity_merge_rq);

int blk_integrity_merge_bio(struct request_queue *q, struct request *req,
			    struct bio *bio)
{
	int nr_integrity_segs;
	struct bio *next = bio->bi_next;

	bio->bi_next = NULL;
	nr_integrity_segs = blk_rq_count_integrity_sg(q, bio);
	bio->bi_next = next;

	if (req->nr_integrity_segments + nr_integrity_segs >
	    q->limits.max_integrity_segments)
		return -1;

	req->nr_integrity_segments += nr_integrity_segs;

	return 0;
}
EXPORT_SYMBOL(blk_integrity_merge_bio);

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)
		bi->flags |= INTEGRITY_FLAG_READ;
	else
		bi->flags &= ~INTEGRITY_FLAG_READ;

	return count;
}

static ssize_t integrity_read_show(struct blk_integrity *bi, char *page)
{
	return sprintf(page, "%d\n", (bi->flags & INTEGRITY_FLAG_READ) != 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)
		bi->flags |= INTEGRITY_FLAG_WRITE;
	else
		bi->flags &= ~INTEGRITY_FLAG_WRITE;

	return count;
}

static ssize_t integrity_write_show(struct blk_integrity *bi, char *page)
{
	return sprintf(page, "%d\n", (bi->flags & INTEGRITY_FLAG_WRITE) != 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 const 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:	optional integrity profile to register
 *
 * 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.  If template is NULL the new profile is allocated but
 * not filled out. 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);

	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_to_dev(disk)->kobj,
					 "%s", "integrity")) {
			kmem_cache_free(integrity_cachep, bi);
			return -1;
		}

		kobject_uevent(&bi->kobj, KOBJ_ADD);

		bi->flags |= INTEGRITY_FLAG_READ | INTEGRITY_FLAG_WRITE;
		bi->sector_size = queue_logical_block_size(disk->queue);
		disk->integrity = bi;
	} else
		bi = disk->integrity;

	/* Use the provided profile as template */
	if (template != NULL) {
		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;
	} else
		bi->name = "unsupported";

	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(&bi->kobj);
	disk->integrity = NULL;
}
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>
5a0e3ad6	27	#include <linux/slab.h>
7ba1ba12 MP	28
	29	#include "blk.h"
	30
	31	static struct kmem_cache *integrity_cachep;
	32
	33	/**
	34	* blk_rq_count_integrity_sg - Count number of integrity scatterlist elements
13f05c8d MP	35	* @q: request queue
13f05c8d MP	36	* @bio: bio with integrity metadata attached
7ba1ba12 MP	37	*
7ba1ba12 MP	38	* Description: Returns the number of elements required in a
13f05c8d	39	* scatterlist corresponding to the integrity metadata in a bio.
7ba1ba12	40	*/
13f05c8d	41	int blk_rq_count_integrity_sg(struct request_queue q, struct bio bio)
7ba1ba12	42	{
13f05c8d MP	43	struct bio_vec iv, ivprv = NULL;
	44	unsigned int segments = 0;
	45	unsigned int seg_size = 0;
	46	unsigned int i = 0;
7ba1ba12	47
13f05c8d	48	bio_for_each_integrity_vec(iv, bio, i) {
7ba1ba12	49
13f05c8d MP	50	if (ivprv) {
	51	if (!BIOVEC_PHYS_MERGEABLE(ivprv, iv))
	52	goto new_segment;
	53
	54	if (!BIOVEC_SEG_BOUNDARY(q, ivprv, iv))
	55	goto new_segment;
	56
	57	if (seg_size + iv->bv_len > queue_max_segment_size(q))
	58	goto new_segment;
7ba1ba12	59
13f05c8d MP	60	seg_size += iv->bv_len;
	61	} else {
	62	new_segment:
7ba1ba12	63	segments++;
13f05c8d MP	64	seg_size = iv->bv_len;
13f05c8d MP	65	}
7ba1ba12 MP	66
	67	ivprv = iv;
	68	}
	69
	70	return segments;
	71	}
	72	EXPORT_SYMBOL(blk_rq_count_integrity_sg);
	73
	74	/**
	75	* blk_rq_map_integrity_sg - Map integrity metadata into a scatterlist
13f05c8d MP	76	* @q: request queue
13f05c8d MP	77	* @bio: bio with integrity metadata attached
7ba1ba12 MP	78	* @sglist: target scatterlist
	79	*
	80	* Description: Map the integrity vectors in request into a
	81	* scatterlist. The scatterlist must be big enough to hold all
	82	* elements. I.e. sized using blk_rq_count_integrity_sg().
	83	*/
13f05c8d MP	84	int blk_rq_map_integrity_sg(struct request_queue q, struct bio bio,
13f05c8d MP	85	struct scatterlist *sglist)
7ba1ba12	86	{
13f05c8d MP	87	struct bio_vec iv, ivprv = NULL;
	88	struct scatterlist *sg = NULL;
	89	unsigned int segments = 0;
	90	unsigned int i = 0;
7ba1ba12	91
13f05c8d	92	bio_for_each_integrity_vec(iv, bio, i) {
7ba1ba12 MP	93
	94	if (ivprv) {
	95	if (!BIOVEC_PHYS_MERGEABLE(ivprv, iv))
	96	goto new_segment;
	97
13f05c8d MP	98	if (!BIOVEC_SEG_BOUNDARY(q, ivprv, iv))
	99	goto new_segment;
	100
	101	if (sg->length + iv->bv_len > queue_max_segment_size(q))
	102	goto new_segment;
	103
7ba1ba12 MP	104	sg->length += iv->bv_len;
	105	} else {
	106	new_segment:
	107	if (!sg)
	108	sg = sglist;
	109	else {
	110	sg->page_link &= ~0x02;
	111	sg = sg_next(sg);
	112	}
	113
	114	sg_set_page(sg, iv->bv_page, iv->bv_len, iv->bv_offset);
	115	segments++;
	116	}
	117
	118	ivprv = iv;
	119	}
	120
	121	if (sg)
	122	sg_mark_end(sg);
	123
	124	return segments;
	125	}
	126	EXPORT_SYMBOL(blk_rq_map_integrity_sg);
	127
	128	/**
ad7fce93 MP	129	* blk_integrity_compare - Compare integrity profile of two disks
	130	* @gd1: Disk to compare
	131	* @gd2: Disk to compare
7ba1ba12 MP	132	*
	133	* Description: Meta-devices like DM and MD need to verify that all
	134	* sub-devices use the same integrity format before advertising to
	135	* upper layers that they can send/receive integrity metadata. This
ad7fce93	136	* function can be used to check whether two gendisk devices have
7ba1ba12 MP	137	* compatible integrity formats.
7ba1ba12 MP	138	*/
ad7fce93	139	int blk_integrity_compare(struct gendisk gd1, struct gendisk gd2)
7ba1ba12	140	{
ad7fce93 MP	141	struct blk_integrity *b1 = gd1->integrity;
ad7fce93 MP	142	struct blk_integrity *b2 = gd2->integrity;
7ba1ba12	143
ad7fce93 MP	144	if (!b1 && !b2)
ad7fce93 MP	145	return 0;
7ba1ba12 MP	146
7ba1ba12 MP	147	if (!b1 \|\| !b2)
ad7fce93	148	return -1;
7ba1ba12 MP	149
	150	if (b1->sector_size != b2->sector_size) {
	151	printk(KERN_ERR "%s: %s/%s sector sz %u != %u\n", __func__,
ad7fce93	152	gd1->disk_name, gd2->disk_name,
7ba1ba12 MP	153	b1->sector_size, b2->sector_size);
	154	return -1;
	155	}
	156
	157	if (b1->tuple_size != b2->tuple_size) {
	158	printk(KERN_ERR "%s: %s/%s tuple sz %u != %u\n", __func__,
ad7fce93	159	gd1->disk_name, gd2->disk_name,
7ba1ba12 MP	160	b1->tuple_size, b2->tuple_size);
	161	return -1;
	162	}
	163
	164	if (b1->tag_size && b2->tag_size && (b1->tag_size != b2->tag_size)) {
	165	printk(KERN_ERR "%s: %s/%s tag sz %u != %u\n", __func__,
ad7fce93	166	gd1->disk_name, gd2->disk_name,
7ba1ba12 MP	167	b1->tag_size, b2->tag_size);
	168	return -1;
	169	}
	170
	171	if (strcmp(b1->name, b2->name)) {
	172	printk(KERN_ERR "%s: %s/%s type %s != %s\n", __func__,
ad7fce93	173	gd1->disk_name, gd2->disk_name,
7ba1ba12 MP	174	b1->name, b2->name);
	175	return -1;
	176	}
	177
	178	return 0;
	179	}
	180	EXPORT_SYMBOL(blk_integrity_compare);
	181
13f05c8d MP	182	int blk_integrity_merge_rq(struct request_queue q, struct request req,
	183	struct request *next)
	184	{
	185	if (blk_integrity_rq(req) != blk_integrity_rq(next))
	186	return -1;
	187
	188	if (req->nr_integrity_segments + next->nr_integrity_segments >
	189	q->limits.max_integrity_segments)
	190	return -1;
	191
	192	return 0;
	193	}
	194	EXPORT_SYMBOL(blk_integrity_merge_rq);
	195
	196	int blk_integrity_merge_bio(struct request_queue q, struct request req,
	197	struct bio *bio)
	198	{
	199	int nr_integrity_segs;
	200	struct bio *next = bio->bi_next;
	201
	202	bio->bi_next = NULL;
	203	nr_integrity_segs = blk_rq_count_integrity_sg(q, bio);
	204	bio->bi_next = next;
	205
	206	if (req->nr_integrity_segments + nr_integrity_segs >
	207	q->limits.max_integrity_segments)
	208	return -1;
	209
	210	req->nr_integrity_segments += nr_integrity_segs;
	211
	212	return 0;
	213	}
	214	EXPORT_SYMBOL(blk_integrity_merge_bio);
	215
7ba1ba12 MP	216	struct integrity_sysfs_entry {
	217	struct attribute attr;
	218	ssize_t (show)(struct blk_integrity , char *);
	219	ssize_t (store)(struct blk_integrity , const char *, size_t);
	220	};
	221
	222	static ssize_t integrity_attr_show(struct kobject kobj, struct attribute attr,
	223	char *page)
	224	{
	225	struct blk_integrity *bi =
	226	container_of(kobj, struct blk_integrity, kobj);
	227	struct integrity_sysfs_entry *entry =
	228	container_of(attr, struct integrity_sysfs_entry, attr);
	229
	230	return entry->show(bi, page);
	231	}
	232
b984679e JA	233	static ssize_t integrity_attr_store(struct kobject *kobj,
	234	struct attribute attr, const char page,
	235	size_t count)
7ba1ba12 MP	236	{
	237	struct blk_integrity *bi =
	238	container_of(kobj, struct blk_integrity, kobj);
	239	struct integrity_sysfs_entry *entry =
	240	container_of(attr, struct integrity_sysfs_entry, attr);
	241	ssize_t ret = 0;
	242
	243	if (entry->store)
	244	ret = entry->store(bi, page, count);
	245
	246	return ret;
	247	}
	248
	249	static ssize_t integrity_format_show(struct blk_integrity bi, char page)
	250	{
	251	if (bi != NULL && bi->name != NULL)
	252	return sprintf(page, "%s\n", bi->name);
	253	else
	254	return sprintf(page, "none\n");
	255	}
	256
	257	static ssize_t integrity_tag_size_show(struct blk_integrity bi, char page)
	258	{
	259	if (bi != NULL)
	260	return sprintf(page, "%u\n", bi->tag_size);
	261	else
	262	return sprintf(page, "0\n");
	263	}
	264
	265	static ssize_t integrity_read_store(struct blk_integrity *bi,
	266	const char *page, size_t count)
	267	{
	268	char p = (char ) page;
	269	unsigned long val = simple_strtoul(p, &p, 10);
	270
	271	if (val)
b24498d4	272	bi->flags \|= INTEGRITY_FLAG_READ;
7ba1ba12	273	else
b24498d4	274	bi->flags &= ~INTEGRITY_FLAG_READ;
7ba1ba12 MP	275
	276	return count;
	277	}
	278
	279	static ssize_t integrity_read_show(struct blk_integrity bi, char page)
	280	{
b24498d4	281	return sprintf(page, "%d\n", (bi->flags & INTEGRITY_FLAG_READ) != 0);
7ba1ba12 MP	282	}
	283
	284	static ssize_t integrity_write_store(struct blk_integrity *bi,
	285	const char *page, size_t count)
	286	{
	287	char p = (char ) page;
	288	unsigned long val = simple_strtoul(p, &p, 10);
	289
	290	if (val)
b24498d4	291	bi->flags \|= INTEGRITY_FLAG_WRITE;
7ba1ba12	292	else
b24498d4	293	bi->flags &= ~INTEGRITY_FLAG_WRITE;
7ba1ba12 MP	294
	295	return count;
	296	}
	297
	298	static ssize_t integrity_write_show(struct blk_integrity bi, char page)
	299	{
b24498d4	300	return sprintf(page, "%d\n", (bi->flags & INTEGRITY_FLAG_WRITE) != 0);
7ba1ba12 MP	301	}
	302
	303	static struct integrity_sysfs_entry integrity_format_entry = {
	304	.attr = { .name = "format", .mode = S_IRUGO },
	305	.show = integrity_format_show,
	306	};
	307
	308	static struct integrity_sysfs_entry integrity_tag_size_entry = {
	309	.attr = { .name = "tag_size", .mode = S_IRUGO },
	310	.show = integrity_tag_size_show,
	311	};
	312
	313	static struct integrity_sysfs_entry integrity_read_entry = {
	314	.attr = { .name = "read_verify", .mode = S_IRUGO \| S_IWUSR },
	315	.show = integrity_read_show,
	316	.store = integrity_read_store,
	317	};
	318
	319	static struct integrity_sysfs_entry integrity_write_entry = {
	320	.attr = { .name = "write_generate", .mode = S_IRUGO \| S_IWUSR },
	321	.show = integrity_write_show,
	322	.store = integrity_write_store,
	323	};
	324
	325	static struct attribute *integrity_attrs[] = {
	326	&integrity_format_entry.attr,
	327	&integrity_tag_size_entry.attr,
	328	&integrity_read_entry.attr,
	329	&integrity_write_entry.attr,
	330	NULL,
	331	};
	332
52cf25d0	333	static const struct sysfs_ops integrity_ops = {
7ba1ba12 MP	334	.show = &integrity_attr_show,
	335	.store = &integrity_attr_store,
	336	};
	337
	338	static int __init blk_dev_integrity_init(void)
	339	{
	340	integrity_cachep = kmem_cache_create("blkdev_integrity",
	341	sizeof(struct blk_integrity),
	342	0, SLAB_PANIC, NULL);
	343	return 0;
	344	}
	345	subsys_initcall(blk_dev_integrity_init);
	346
	347	static void blk_integrity_release(struct kobject *kobj)
	348	{
	349	struct blk_integrity *bi =
	350	container_of(kobj, struct blk_integrity, kobj);
	351
	352	kmem_cache_free(integrity_cachep, bi);
	353	}
	354
	355	static struct kobj_type integrity_ktype = {
	356	.default_attrs = integrity_attrs,
	357	.sysfs_ops = &integrity_ops,
	358	.release = blk_integrity_release,
	359	};
	360
	361	/**
	362	* blk_integrity_register - Register a gendisk as being integrity-capable
	363	* @disk: struct gendisk pointer to make integrity-aware
32231638	364	* @template: optional integrity profile to register
7ba1ba12 MP	365	*
	366	* Description: When a device needs to advertise itself as being able
	367	* to send/receive integrity metadata it must use this function to
	368	* register the capability with the block layer. The template is a
	369	* blk_integrity struct with values appropriate for the underlying
32231638 MP	370	* hardware. If template is NULL the new profile is allocated but
32231638 MP	371	* not filled out. See Documentation/block/data-integrity.txt.
7ba1ba12 MP	372	*/
	373	int blk_integrity_register(struct gendisk disk, struct blk_integrity template)
	374	{
	375	struct blk_integrity *bi;
	376
	377	BUG_ON(disk == NULL);
7ba1ba12 MP	378
7ba1ba12 MP	379	if (disk->integrity == NULL) {
b984679e	380	bi = kmem_cache_alloc(integrity_cachep,
32231638	381	GFP_KERNEL \| __GFP_ZERO);
7ba1ba12 MP	382	if (!bi)
	383	return -1;
	384
	385	if (kobject_init_and_add(&bi->kobj, &integrity_ktype,
ed9e1982 TH	386	&disk_to_dev(disk)->kobj,
ed9e1982 TH	387	"%s", "integrity")) {
7ba1ba12 MP	388	kmem_cache_free(integrity_cachep, bi);
	389	return -1;
	390	}
	391
	392	kobject_uevent(&bi->kobj, KOBJ_ADD);
	393
b24498d4	394	bi->flags \|= INTEGRITY_FLAG_READ \| INTEGRITY_FLAG_WRITE;
e1defc4f	395	bi->sector_size = queue_logical_block_size(disk->queue);
7ba1ba12 MP	396	disk->integrity = bi;
	397	} else
	398	bi = disk->integrity;
	399
	400	/* Use the provided profile as template */
32231638 MP	401	if (template != NULL) {
	402	bi->name = template->name;
	403	bi->generate_fn = template->generate_fn;
	404	bi->verify_fn = template->verify_fn;
	405	bi->tuple_size = template->tuple_size;
	406	bi->set_tag_fn = template->set_tag_fn;
	407	bi->get_tag_fn = template->get_tag_fn;
	408	bi->tag_size = template->tag_size;
	409	} else
	410	bi->name = "unsupported";
7ba1ba12 MP	411
	412	return 0;
	413	}
	414	EXPORT_SYMBOL(blk_integrity_register);
	415
	416	/**
	417	* blk_integrity_unregister - Remove block integrity profile
	418	* @disk: disk whose integrity profile to deallocate
	419	*
	420	* Description: This function frees all memory used by the block
	421	* integrity profile. To be called at device teardown.
	422	*/
	423	void blk_integrity_unregister(struct gendisk *disk)
	424	{
	425	struct blk_integrity *bi;
	426
	427	if (!disk \|\| !disk->integrity)
	428	return;
	429
	430	bi = disk->integrity;
	431
	432	kobject_uevent(&bi->kobj, KOBJ_REMOVE);
	433	kobject_del(&bi->kobj);
3839e4b2	434	kobject_put(&bi->kobj);
0c032ab8	435	disk->integrity = NULL;
7ba1ba12 MP	436	}
7ba1ba12 MP	437	EXPORT_SYMBOL(blk_integrity_unregister);