[linux.git] / block / blk-integrity.c

/*
 * blk-integrity.c - Block layer data integrity extensions
 *
 * Copyright (C) 2007, 2008 Oracle Corporation
 * Written by: Martin K. Petersen <[email protected]>
 *
 * 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;

static const char *bi_unsupported_name = "unsupported";

/**
 * 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,
};

bool blk_integrity_is_initialized(struct gendisk *disk)
{
	struct blk_integrity *bi = blk_get_integrity(disk);

	return (bi && bi->name && strcmp(bi->name, bi_unsupported_name) != 0);
}
EXPORT_SYMBOL(blk_integrity_is_initialized);

/**
 * 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 = bi_unsupported_name;

	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 <[email protected]>
	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
a63a5cf8 MS	33	static const char *bi_unsupported_name = "unsupported";
a63a5cf8 MS	34
7ba1ba12 MP	35	/**
7ba1ba12 MP	36	* blk_rq_count_integrity_sg - Count number of integrity scatterlist elements
13f05c8d MP	37	* @q: request queue
13f05c8d MP	38	* @bio: bio with integrity metadata attached
7ba1ba12 MP	39	*
7ba1ba12 MP	40	* Description: Returns the number of elements required in a
13f05c8d	41	* scatterlist corresponding to the integrity metadata in a bio.
7ba1ba12	42	*/
13f05c8d	43	int blk_rq_count_integrity_sg(struct request_queue q, struct bio bio)
7ba1ba12	44	{
13f05c8d MP	45	struct bio_vec iv, ivprv = NULL;
	46	unsigned int segments = 0;
	47	unsigned int seg_size = 0;
	48	unsigned int i = 0;
7ba1ba12	49
13f05c8d	50	bio_for_each_integrity_vec(iv, bio, i) {
7ba1ba12	51
13f05c8d MP	52	if (ivprv) {
	53	if (!BIOVEC_PHYS_MERGEABLE(ivprv, iv))
	54	goto new_segment;
	55
	56	if (!BIOVEC_SEG_BOUNDARY(q, ivprv, iv))
	57	goto new_segment;
	58
	59	if (seg_size + iv->bv_len > queue_max_segment_size(q))
	60	goto new_segment;
7ba1ba12	61
13f05c8d MP	62	seg_size += iv->bv_len;
	63	} else {
	64	new_segment:
7ba1ba12	65	segments++;
13f05c8d MP	66	seg_size = iv->bv_len;
13f05c8d MP	67	}
7ba1ba12 MP	68
	69	ivprv = iv;
	70	}
	71
	72	return segments;
	73	}
	74	EXPORT_SYMBOL(blk_rq_count_integrity_sg);
	75
	76	/**
	77	* blk_rq_map_integrity_sg - Map integrity metadata into a scatterlist
13f05c8d MP	78	* @q: request queue
13f05c8d MP	79	* @bio: bio with integrity metadata attached
7ba1ba12 MP	80	* @sglist: target scatterlist
	81	*
	82	* Description: Map the integrity vectors in request into a
	83	* scatterlist. The scatterlist must be big enough to hold all
	84	* elements. I.e. sized using blk_rq_count_integrity_sg().
	85	*/
13f05c8d MP	86	int blk_rq_map_integrity_sg(struct request_queue q, struct bio bio,
13f05c8d MP	87	struct scatterlist *sglist)
7ba1ba12	88	{
13f05c8d MP	89	struct bio_vec iv, ivprv = NULL;
	90	struct scatterlist *sg = NULL;
	91	unsigned int segments = 0;
	92	unsigned int i = 0;
7ba1ba12	93
13f05c8d	94	bio_for_each_integrity_vec(iv, bio, i) {
7ba1ba12 MP	95
	96	if (ivprv) {
	97	if (!BIOVEC_PHYS_MERGEABLE(ivprv, iv))
	98	goto new_segment;
	99
13f05c8d MP	100	if (!BIOVEC_SEG_BOUNDARY(q, ivprv, iv))
	101	goto new_segment;
	102
	103	if (sg->length + iv->bv_len > queue_max_segment_size(q))
	104	goto new_segment;
	105
7ba1ba12 MP	106	sg->length += iv->bv_len;
	107	} else {
	108	new_segment:
	109	if (!sg)
	110	sg = sglist;
	111	else {
	112	sg->page_link &= ~0x02;
	113	sg = sg_next(sg);
	114	}
	115
	116	sg_set_page(sg, iv->bv_page, iv->bv_len, iv->bv_offset);
	117	segments++;
	118	}
	119
	120	ivprv = iv;
	121	}
	122
	123	if (sg)
	124	sg_mark_end(sg);
	125
	126	return segments;
	127	}
	128	EXPORT_SYMBOL(blk_rq_map_integrity_sg);
	129
	130	/**
ad7fce93 MP	131	* blk_integrity_compare - Compare integrity profile of two disks
	132	* @gd1: Disk to compare
	133	* @gd2: Disk to compare
7ba1ba12 MP	134	*
	135	* Description: Meta-devices like DM and MD need to verify that all
	136	* sub-devices use the same integrity format before advertising to
	137	* upper layers that they can send/receive integrity metadata. This
ad7fce93	138	* function can be used to check whether two gendisk devices have
7ba1ba12 MP	139	* compatible integrity formats.
7ba1ba12 MP	140	*/
ad7fce93	141	int blk_integrity_compare(struct gendisk gd1, struct gendisk gd2)
7ba1ba12	142	{
ad7fce93 MP	143	struct blk_integrity *b1 = gd1->integrity;
ad7fce93 MP	144	struct blk_integrity *b2 = gd2->integrity;
7ba1ba12	145
ad7fce93 MP	146	if (!b1 && !b2)
ad7fce93 MP	147	return 0;
7ba1ba12 MP	148
7ba1ba12 MP	149	if (!b1 \|\| !b2)
ad7fce93	150	return -1;
7ba1ba12 MP	151
	152	if (b1->sector_size != b2->sector_size) {
	153	printk(KERN_ERR "%s: %s/%s sector sz %u != %u\n", __func__,
ad7fce93	154	gd1->disk_name, gd2->disk_name,
7ba1ba12 MP	155	b1->sector_size, b2->sector_size);
	156	return -1;
	157	}
	158
	159	if (b1->tuple_size != b2->tuple_size) {
	160	printk(KERN_ERR "%s: %s/%s tuple sz %u != %u\n", __func__,
ad7fce93	161	gd1->disk_name, gd2->disk_name,
7ba1ba12 MP	162	b1->tuple_size, b2->tuple_size);
	163	return -1;
	164	}
	165
	166	if (b1->tag_size && b2->tag_size && (b1->tag_size != b2->tag_size)) {
	167	printk(KERN_ERR "%s: %s/%s tag sz %u != %u\n", __func__,
ad7fce93	168	gd1->disk_name, gd2->disk_name,
7ba1ba12 MP	169	b1->tag_size, b2->tag_size);
	170	return -1;
	171	}
	172
	173	if (strcmp(b1->name, b2->name)) {
	174	printk(KERN_ERR "%s: %s/%s type %s != %s\n", __func__,
ad7fce93	175	gd1->disk_name, gd2->disk_name,
7ba1ba12 MP	176	b1->name, b2->name);
	177	return -1;
	178	}
	179
	180	return 0;
	181	}
	182	EXPORT_SYMBOL(blk_integrity_compare);
	183
13f05c8d MP	184	int blk_integrity_merge_rq(struct request_queue q, struct request req,
	185	struct request *next)
	186	{
	187	if (blk_integrity_rq(req) != blk_integrity_rq(next))
	188	return -1;
	189
	190	if (req->nr_integrity_segments + next->nr_integrity_segments >
	191	q->limits.max_integrity_segments)
	192	return -1;
	193
	194	return 0;
	195	}
	196	EXPORT_SYMBOL(blk_integrity_merge_rq);
	197
	198	int blk_integrity_merge_bio(struct request_queue q, struct request req,
	199	struct bio *bio)
	200	{
	201	int nr_integrity_segs;
	202	struct bio *next = bio->bi_next;
	203
	204	bio->bi_next = NULL;
	205	nr_integrity_segs = blk_rq_count_integrity_sg(q, bio);
	206	bio->bi_next = next;
	207
	208	if (req->nr_integrity_segments + nr_integrity_segs >
	209	q->limits.max_integrity_segments)
	210	return -1;
	211
	212	req->nr_integrity_segments += nr_integrity_segs;
	213
	214	return 0;
	215	}
	216	EXPORT_SYMBOL(blk_integrity_merge_bio);
	217
7ba1ba12 MP	218	struct integrity_sysfs_entry {
	219	struct attribute attr;
	220	ssize_t (show)(struct blk_integrity , char *);
	221	ssize_t (store)(struct blk_integrity , const char *, size_t);
	222	};
	223
	224	static ssize_t integrity_attr_show(struct kobject kobj, struct attribute attr,
	225	char *page)
	226	{
	227	struct blk_integrity *bi =
	228	container_of(kobj, struct blk_integrity, kobj);
	229	struct integrity_sysfs_entry *entry =
	230	container_of(attr, struct integrity_sysfs_entry, attr);
	231
	232	return entry->show(bi, page);
	233	}
	234
b984679e JA	235	static ssize_t integrity_attr_store(struct kobject *kobj,
	236	struct attribute attr, const char page,
	237	size_t count)
7ba1ba12 MP	238	{
	239	struct blk_integrity *bi =
	240	container_of(kobj, struct blk_integrity, kobj);
	241	struct integrity_sysfs_entry *entry =
	242	container_of(attr, struct integrity_sysfs_entry, attr);
	243	ssize_t ret = 0;
	244
	245	if (entry->store)
	246	ret = entry->store(bi, page, count);
	247
	248	return ret;
	249	}
	250
	251	static ssize_t integrity_format_show(struct blk_integrity bi, char page)
	252	{
	253	if (bi != NULL && bi->name != NULL)
	254	return sprintf(page, "%s\n", bi->name);
	255	else
	256	return sprintf(page, "none\n");
	257	}
	258
	259	static ssize_t integrity_tag_size_show(struct blk_integrity bi, char page)
	260	{
	261	if (bi != NULL)
	262	return sprintf(page, "%u\n", bi->tag_size);
	263	else
	264	return sprintf(page, "0\n");
	265	}
	266
	267	static ssize_t integrity_read_store(struct blk_integrity *bi,
	268	const char *page, size_t count)
	269	{
	270	char p = (char ) page;
	271	unsigned long val = simple_strtoul(p, &p, 10);
	272
	273	if (val)
b24498d4	274	bi->flags \|= INTEGRITY_FLAG_READ;
7ba1ba12	275	else
b24498d4	276	bi->flags &= ~INTEGRITY_FLAG_READ;
7ba1ba12 MP	277
	278	return count;
	279	}
	280
	281	static ssize_t integrity_read_show(struct blk_integrity bi, char page)
	282	{
b24498d4	283	return sprintf(page, "%d\n", (bi->flags & INTEGRITY_FLAG_READ) != 0);
7ba1ba12 MP	284	}
	285
	286	static ssize_t integrity_write_store(struct blk_integrity *bi,
	287	const char *page, size_t count)
	288	{
	289	char p = (char ) page;
	290	unsigned long val = simple_strtoul(p, &p, 10);
	291
	292	if (val)
b24498d4	293	bi->flags \|= INTEGRITY_FLAG_WRITE;
7ba1ba12	294	else
b24498d4	295	bi->flags &= ~INTEGRITY_FLAG_WRITE;
7ba1ba12 MP	296
	297	return count;
	298	}
	299
	300	static ssize_t integrity_write_show(struct blk_integrity bi, char page)
	301	{
b24498d4	302	return sprintf(page, "%d\n", (bi->flags & INTEGRITY_FLAG_WRITE) != 0);
7ba1ba12 MP	303	}
	304
	305	static struct integrity_sysfs_entry integrity_format_entry = {
	306	.attr = { .name = "format", .mode = S_IRUGO },
	307	.show = integrity_format_show,
	308	};
	309
	310	static struct integrity_sysfs_entry integrity_tag_size_entry = {
	311	.attr = { .name = "tag_size", .mode = S_IRUGO },
	312	.show = integrity_tag_size_show,
	313	};
	314
	315	static struct integrity_sysfs_entry integrity_read_entry = {
	316	.attr = { .name = "read_verify", .mode = S_IRUGO \| S_IWUSR },
	317	.show = integrity_read_show,
	318	.store = integrity_read_store,
	319	};
	320
	321	static struct integrity_sysfs_entry integrity_write_entry = {
	322	.attr = { .name = "write_generate", .mode = S_IRUGO \| S_IWUSR },
	323	.show = integrity_write_show,
	324	.store = integrity_write_store,
	325	};
	326
	327	static struct attribute *integrity_attrs[] = {
	328	&integrity_format_entry.attr,
	329	&integrity_tag_size_entry.attr,
	330	&integrity_read_entry.attr,
	331	&integrity_write_entry.attr,
	332	NULL,
	333	};
	334
52cf25d0	335	static const struct sysfs_ops integrity_ops = {
7ba1ba12 MP	336	.show = &integrity_attr_show,
	337	.store = &integrity_attr_store,
	338	};
	339
	340	static int __init blk_dev_integrity_init(void)
	341	{
	342	integrity_cachep = kmem_cache_create("blkdev_integrity",
	343	sizeof(struct blk_integrity),
	344	0, SLAB_PANIC, NULL);
	345	return 0;
	346	}
	347	subsys_initcall(blk_dev_integrity_init);
	348
	349	static void blk_integrity_release(struct kobject *kobj)
	350	{
	351	struct blk_integrity *bi =
	352	container_of(kobj, struct blk_integrity, kobj);
	353
	354	kmem_cache_free(integrity_cachep, bi);
	355	}
	356
	357	static struct kobj_type integrity_ktype = {
	358	.default_attrs = integrity_attrs,
	359	.sysfs_ops = &integrity_ops,
	360	.release = blk_integrity_release,
	361	};
	362
a63a5cf8 MS	363	bool blk_integrity_is_initialized(struct gendisk *disk)
	364	{
	365	struct blk_integrity *bi = blk_get_integrity(disk);
	366
	367	return (bi && bi->name && strcmp(bi->name, bi_unsupported_name) != 0);
	368	}
	369	EXPORT_SYMBOL(blk_integrity_is_initialized);
	370
7ba1ba12 MP	371	/**
	372	* blk_integrity_register - Register a gendisk as being integrity-capable
	373	* @disk: struct gendisk pointer to make integrity-aware
32231638	374	* @template: optional integrity profile to register
7ba1ba12 MP	375	*
	376	* Description: When a device needs to advertise itself as being able
	377	* to send/receive integrity metadata it must use this function to
	378	* register the capability with the block layer. The template is a
	379	* blk_integrity struct with values appropriate for the underlying
32231638 MP	380	* hardware. If template is NULL the new profile is allocated but
32231638 MP	381	* not filled out. See Documentation/block/data-integrity.txt.
7ba1ba12 MP	382	*/
	383	int blk_integrity_register(struct gendisk disk, struct blk_integrity template)
	384	{
	385	struct blk_integrity *bi;
	386
	387	BUG_ON(disk == NULL);
7ba1ba12 MP	388
7ba1ba12 MP	389	if (disk->integrity == NULL) {
b984679e	390	bi = kmem_cache_alloc(integrity_cachep,
32231638	391	GFP_KERNEL \| __GFP_ZERO);
7ba1ba12 MP	392	if (!bi)
	393	return -1;
	394
	395	if (kobject_init_and_add(&bi->kobj, &integrity_ktype,
ed9e1982 TH	396	&disk_to_dev(disk)->kobj,
ed9e1982 TH	397	"%s", "integrity")) {
7ba1ba12 MP	398	kmem_cache_free(integrity_cachep, bi);
	399	return -1;
	400	}
	401
	402	kobject_uevent(&bi->kobj, KOBJ_ADD);
	403
b24498d4	404	bi->flags \|= INTEGRITY_FLAG_READ \| INTEGRITY_FLAG_WRITE;
e1defc4f	405	bi->sector_size = queue_logical_block_size(disk->queue);
7ba1ba12 MP	406	disk->integrity = bi;
	407	} else
	408	bi = disk->integrity;
	409
	410	/* Use the provided profile as template */
32231638 MP	411	if (template != NULL) {
	412	bi->name = template->name;
	413	bi->generate_fn = template->generate_fn;
	414	bi->verify_fn = template->verify_fn;
	415	bi->tuple_size = template->tuple_size;
	416	bi->set_tag_fn = template->set_tag_fn;
	417	bi->get_tag_fn = template->get_tag_fn;
	418	bi->tag_size = template->tag_size;
	419	} else
a63a5cf8	420	bi->name = bi_unsupported_name;
7ba1ba12 MP	421
	422	return 0;
	423	}
	424	EXPORT_SYMBOL(blk_integrity_register);
	425
	426	/**
	427	* blk_integrity_unregister - Remove block integrity profile
	428	* @disk: disk whose integrity profile to deallocate
	429	*
	430	* Description: This function frees all memory used by the block
	431	* integrity profile. To be called at device teardown.
	432	*/
	433	void blk_integrity_unregister(struct gendisk *disk)
	434	{
	435	struct blk_integrity *bi;
	436
	437	if (!disk \|\| !disk->integrity)
	438	return;
	439
	440	bi = disk->integrity;
	441
	442	kobject_uevent(&bi->kobj, KOBJ_REMOVE);
	443	kobject_del(&bi->kobj);
3839e4b2	444	kobject_put(&bi->kobj);
0c032ab8	445	disk->integrity = NULL;
7ba1ba12 MP	446	}
7ba1ba12 MP	447	EXPORT_SYMBOL(blk_integrity_unregister);