[linux-2.6-block.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/backing-dev.h>
#include <linux/mempool.h>
#include <linux/bio.h>
#include <linux/scatterlist.h>
#include <linux/export.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;
	struct bvec_iter iter;
	int prev = 0;

	bio_for_each_integrity_vec(iv, bio, iter) {

		if (prev) {
			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;
		}

		prev = 1;
		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;
	struct bvec_iter iter;
	int prev = 0;

	bio_for_each_integrity_vec(iv, bio, iter) {

		if (prev) {
			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_unmark_end(sg);
				sg = sg_next(sg);
			}

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

		prev = 1;
		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->interval != b2->interval) {
		pr_err("%s: %s/%s protection interval %u != %u\n",
		       __func__, gd1->disk_name, gd2->disk_name,
		       b1->interval, b2->interval);
		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);

bool blk_integrity_merge_rq(struct request_queue *q, struct request *req,
			    struct request *next)
{
	if (blk_integrity_rq(req) == 0 && blk_integrity_rq(next) == 0)
		return true;

	if (blk_integrity_rq(req) == 0 || blk_integrity_rq(next) == 0)
		return false;

	if (bio_integrity(req->bio)->bip_flags !=
	    bio_integrity(next->bio)->bip_flags)
		return false;

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

	return true;
}
EXPORT_SYMBOL(blk_integrity_merge_rq);

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

	if (blk_integrity_rq(req) == 0 && bio_integrity(bio) == NULL)
		return true;

	if (blk_integrity_rq(req) == 0 || bio_integrity(bio) == NULL)
		return false;

	if (bio_integrity(req->bio)->bip_flags != bio_integrity(bio)->bip_flags)
		return false;

	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 false;

	req->nr_integrity_segments += nr_integrity_segs;

	return true;
}
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_verify_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 |= BLK_INTEGRITY_VERIFY;
	else
		bi->flags &= ~BLK_INTEGRITY_VERIFY;

	return count;
}

static ssize_t integrity_verify_show(struct blk_integrity *bi, char *page)
{
	return sprintf(page, "%d\n", (bi->flags & BLK_INTEGRITY_VERIFY) != 0);
}

static ssize_t integrity_generate_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 |= BLK_INTEGRITY_GENERATE;
	else
		bi->flags &= ~BLK_INTEGRITY_GENERATE;

	return count;
}

static ssize_t integrity_generate_show(struct blk_integrity *bi, char *page)
{
	return sprintf(page, "%d\n", (bi->flags & BLK_INTEGRITY_GENERATE) != 0);
}

static ssize_t integrity_device_show(struct blk_integrity *bi, char *page)
{
	return sprintf(page, "%u\n",
		       (bi->flags & BLK_INTEGRITY_DEVICE_CAPABLE) != 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_verify_entry = {
	.attr = { .name = "read_verify", .mode = S_IRUGO | S_IWUSR },
	.show = integrity_verify_show,
	.store = integrity_verify_store,
};

static struct integrity_sysfs_entry integrity_generate_entry = {
	.attr = { .name = "write_generate", .mode = S_IRUGO | S_IWUSR },
	.show = integrity_generate_show,
	.store = integrity_generate_store,
};

static struct integrity_sysfs_entry integrity_device_entry = {
	.attr = { .name = "device_is_integrity_capable", .mode = S_IRUGO },
	.show = integrity_device_show,
};

static struct attribute *integrity_attrs[] = {
	&integrity_format_entry.attr,
	&integrity_tag_size_entry.attr,
	&integrity_verify_entry.attr,
	&integrity_generate_entry.attr,
	&integrity_device_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 |= BLK_INTEGRITY_VERIFY | BLK_INTEGRITY_GENERATE;
		bi->interval = 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->tag_size = template->tag_size;
		bi->flags |= template->flags;
	} else
		bi->name = bi_unsupported_name;

	disk->queue->backing_dev_info.capabilities |= BDI_CAP_STABLE_WRITES;

	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;

	disk->queue->backing_dev_info.capabilities &= ~BDI_CAP_STABLE_WRITES;

	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>
66114cad	24	#include <linux/backing-dev.h>
7ba1ba12 MP	25	#include <linux/mempool.h>
	26	#include <linux/bio.h>
	27	#include <linux/scatterlist.h>
d5decd3b	28	#include <linux/export.h>
5a0e3ad6	29	#include <linux/slab.h>
7ba1ba12 MP	30
	31	#include "blk.h"
	32
	33	static struct kmem_cache *integrity_cachep;
	34
a63a5cf8 MS	35	static const char *bi_unsupported_name = "unsupported";
a63a5cf8 MS	36
7ba1ba12 MP	37	/**
7ba1ba12 MP	38	* blk_rq_count_integrity_sg - Count number of integrity scatterlist elements
13f05c8d MP	39	* @q: request queue
13f05c8d MP	40	* @bio: bio with integrity metadata attached
7ba1ba12 MP	41	*
7ba1ba12 MP	42	* Description: Returns the number of elements required in a
13f05c8d	43	* scatterlist corresponding to the integrity metadata in a bio.
7ba1ba12	44	*/
13f05c8d	45	int blk_rq_count_integrity_sg(struct request_queue q, struct bio bio)
7ba1ba12	46	{
d57a5f7c	47	struct bio_vec iv, ivprv = { NULL };
13f05c8d MP	48	unsigned int segments = 0;
13f05c8d MP	49	unsigned int seg_size = 0;
d57a5f7c KO	50	struct bvec_iter iter;
d57a5f7c KO	51	int prev = 0;
7ba1ba12	52
d57a5f7c	53	bio_for_each_integrity_vec(iv, bio, iter) {
7ba1ba12	54
d57a5f7c KO	55	if (prev) {
d57a5f7c KO	56	if (!BIOVEC_PHYS_MERGEABLE(&ivprv, &iv))
13f05c8d MP	57	goto new_segment;
13f05c8d MP	58
d57a5f7c	59	if (!BIOVEC_SEG_BOUNDARY(q, &ivprv, &iv))
13f05c8d MP	60	goto new_segment;
13f05c8d MP	61
d57a5f7c	62	if (seg_size + iv.bv_len > queue_max_segment_size(q))
13f05c8d	63	goto new_segment;
7ba1ba12	64
d57a5f7c	65	seg_size += iv.bv_len;
13f05c8d MP	66	} else {
13f05c8d MP	67	new_segment:
7ba1ba12	68	segments++;
d57a5f7c	69	seg_size = iv.bv_len;
13f05c8d	70	}
7ba1ba12	71
d57a5f7c	72	prev = 1;
7ba1ba12 MP	73	ivprv = iv;
	74	}
	75
	76	return segments;
	77	}
	78	EXPORT_SYMBOL(blk_rq_count_integrity_sg);
	79
	80	/**
	81	* blk_rq_map_integrity_sg - Map integrity metadata into a scatterlist
13f05c8d MP	82	* @q: request queue
13f05c8d MP	83	* @bio: bio with integrity metadata attached
7ba1ba12 MP	84	* @sglist: target scatterlist
	85	*
	86	* Description: Map the integrity vectors in request into a
	87	* scatterlist. The scatterlist must be big enough to hold all
	88	* elements. I.e. sized using blk_rq_count_integrity_sg().
	89	*/
13f05c8d MP	90	int blk_rq_map_integrity_sg(struct request_queue q, struct bio bio,
13f05c8d MP	91	struct scatterlist *sglist)
7ba1ba12	92	{
d57a5f7c	93	struct bio_vec iv, ivprv = { NULL };
13f05c8d MP	94	struct scatterlist *sg = NULL;
13f05c8d MP	95	unsigned int segments = 0;
d57a5f7c KO	96	struct bvec_iter iter;
d57a5f7c KO	97	int prev = 0;
7ba1ba12	98
d57a5f7c	99	bio_for_each_integrity_vec(iv, bio, iter) {
7ba1ba12	100
d57a5f7c KO	101	if (prev) {
d57a5f7c KO	102	if (!BIOVEC_PHYS_MERGEABLE(&ivprv, &iv))
7ba1ba12 MP	103	goto new_segment;
7ba1ba12 MP	104
d57a5f7c	105	if (!BIOVEC_SEG_BOUNDARY(q, &ivprv, &iv))
13f05c8d MP	106	goto new_segment;
13f05c8d MP	107
d57a5f7c	108	if (sg->length + iv.bv_len > queue_max_segment_size(q))
13f05c8d MP	109	goto new_segment;
13f05c8d MP	110
d57a5f7c	111	sg->length += iv.bv_len;
7ba1ba12 MP	112	} else {
	113	new_segment:
	114	if (!sg)
	115	sg = sglist;
	116	else {
c8164d89	117	sg_unmark_end(sg);
7ba1ba12 MP	118	sg = sg_next(sg);
	119	}
	120
d57a5f7c	121	sg_set_page(sg, iv.bv_page, iv.bv_len, iv.bv_offset);
7ba1ba12 MP	122	segments++;
	123	}
	124
d57a5f7c	125	prev = 1;
7ba1ba12 MP	126	ivprv = iv;
	127	}
	128
	129	if (sg)
	130	sg_mark_end(sg);
	131
	132	return segments;
	133	}
	134	EXPORT_SYMBOL(blk_rq_map_integrity_sg);
	135
	136	/**
ad7fce93 MP	137	* blk_integrity_compare - Compare integrity profile of two disks
	138	* @gd1: Disk to compare
	139	* @gd2: Disk to compare
7ba1ba12 MP	140	*
	141	* Description: Meta-devices like DM and MD need to verify that all
	142	* sub-devices use the same integrity format before advertising to
	143	* upper layers that they can send/receive integrity metadata. This
ad7fce93	144	* function can be used to check whether two gendisk devices have
7ba1ba12 MP	145	* compatible integrity formats.
7ba1ba12 MP	146	*/
ad7fce93	147	int blk_integrity_compare(struct gendisk gd1, struct gendisk gd2)
7ba1ba12	148	{
ad7fce93 MP	149	struct blk_integrity *b1 = gd1->integrity;
ad7fce93 MP	150	struct blk_integrity *b2 = gd2->integrity;
7ba1ba12	151
ad7fce93 MP	152	if (!b1 && !b2)
ad7fce93 MP	153	return 0;
7ba1ba12 MP	154
7ba1ba12 MP	155	if (!b1 \|\| !b2)
ad7fce93	156	return -1;
7ba1ba12	157
3be91c4a MP	158	if (b1->interval != b2->interval) {
	159	pr_err("%s: %s/%s protection interval %u != %u\n",
	160	__func__, gd1->disk_name, gd2->disk_name,
	161	b1->interval, b2->interval);
7ba1ba12 MP	162	return -1;
	163	}
	164
	165	if (b1->tuple_size != b2->tuple_size) {
	166	printk(KERN_ERR "%s: %s/%s tuple sz %u != %u\n", __func__,
ad7fce93	167	gd1->disk_name, gd2->disk_name,
7ba1ba12 MP	168	b1->tuple_size, b2->tuple_size);
	169	return -1;
	170	}
	171
	172	if (b1->tag_size && b2->tag_size && (b1->tag_size != b2->tag_size)) {
	173	printk(KERN_ERR "%s: %s/%s tag sz %u != %u\n", __func__,
ad7fce93	174	gd1->disk_name, gd2->disk_name,
7ba1ba12 MP	175	b1->tag_size, b2->tag_size);
	176	return -1;
	177	}
	178
	179	if (strcmp(b1->name, b2->name)) {
	180	printk(KERN_ERR "%s: %s/%s type %s != %s\n", __func__,
ad7fce93	181	gd1->disk_name, gd2->disk_name,
7ba1ba12 MP	182	b1->name, b2->name);
	183	return -1;
	184	}
	185
	186	return 0;
	187	}
	188	EXPORT_SYMBOL(blk_integrity_compare);
	189
4eaf99be MP	190	bool blk_integrity_merge_rq(struct request_queue q, struct request req,
4eaf99be MP	191	struct request *next)
13f05c8d	192	{
4eaf99be MP	193	if (blk_integrity_rq(req) == 0 && blk_integrity_rq(next) == 0)
	194	return true;
	195
	196	if (blk_integrity_rq(req) == 0 \|\| blk_integrity_rq(next) == 0)
	197	return false;
	198
	199	if (bio_integrity(req->bio)->bip_flags !=
	200	bio_integrity(next->bio)->bip_flags)
	201	return false;
13f05c8d MP	202
	203	if (req->nr_integrity_segments + next->nr_integrity_segments >
	204	q->limits.max_integrity_segments)
4eaf99be	205	return false;
13f05c8d	206
4eaf99be	207	return true;
13f05c8d MP	208	}
	209	EXPORT_SYMBOL(blk_integrity_merge_rq);
	210
4eaf99be MP	211	bool blk_integrity_merge_bio(struct request_queue q, struct request req,
4eaf99be MP	212	struct bio *bio)
13f05c8d MP	213	{
	214	int nr_integrity_segs;
	215	struct bio *next = bio->bi_next;
	216
4eaf99be MP	217	if (blk_integrity_rq(req) == 0 && bio_integrity(bio) == NULL)
	218	return true;
	219
	220	if (blk_integrity_rq(req) == 0 \|\| bio_integrity(bio) == NULL)
	221	return false;
	222
	223	if (bio_integrity(req->bio)->bip_flags != bio_integrity(bio)->bip_flags)
	224	return false;
	225
13f05c8d MP	226	bio->bi_next = NULL;
	227	nr_integrity_segs = blk_rq_count_integrity_sg(q, bio);
	228	bio->bi_next = next;
	229
	230	if (req->nr_integrity_segments + nr_integrity_segs >
	231	q->limits.max_integrity_segments)
4eaf99be	232	return false;
13f05c8d MP	233
	234	req->nr_integrity_segments += nr_integrity_segs;
	235
4eaf99be	236	return true;
13f05c8d MP	237	}
	238	EXPORT_SYMBOL(blk_integrity_merge_bio);
	239
7ba1ba12 MP	240	struct integrity_sysfs_entry {
	241	struct attribute attr;
	242	ssize_t (show)(struct blk_integrity , char *);
	243	ssize_t (store)(struct blk_integrity , const char *, size_t);
	244	};
	245
	246	static ssize_t integrity_attr_show(struct kobject kobj, struct attribute attr,
	247	char *page)
	248	{
	249	struct blk_integrity *bi =
	250	container_of(kobj, struct blk_integrity, kobj);
	251	struct integrity_sysfs_entry *entry =
	252	container_of(attr, struct integrity_sysfs_entry, attr);
	253
	254	return entry->show(bi, page);
	255	}
	256
b984679e JA	257	static ssize_t integrity_attr_store(struct kobject *kobj,
	258	struct attribute attr, const char page,
	259	size_t count)
7ba1ba12 MP	260	{
	261	struct blk_integrity *bi =
	262	container_of(kobj, struct blk_integrity, kobj);
	263	struct integrity_sysfs_entry *entry =
	264	container_of(attr, struct integrity_sysfs_entry, attr);
	265	ssize_t ret = 0;
	266
	267	if (entry->store)
	268	ret = entry->store(bi, page, count);
	269
	270	return ret;
	271	}
	272
	273	static ssize_t integrity_format_show(struct blk_integrity bi, char page)
	274	{
	275	if (bi != NULL && bi->name != NULL)
	276	return sprintf(page, "%s\n", bi->name);
	277	else
	278	return sprintf(page, "none\n");
	279	}
	280
	281	static ssize_t integrity_tag_size_show(struct blk_integrity bi, char page)
	282	{
	283	if (bi != NULL)
	284	return sprintf(page, "%u\n", bi->tag_size);
	285	else
	286	return sprintf(page, "0\n");
	287	}
	288
8288f496 MP	289	static ssize_t integrity_verify_store(struct blk_integrity *bi,
8288f496 MP	290	const char *page, size_t count)
7ba1ba12 MP	291	{
	292	char p = (char ) page;
	293	unsigned long val = simple_strtoul(p, &p, 10);
	294
	295	if (val)
8288f496	296	bi->flags \|= BLK_INTEGRITY_VERIFY;
7ba1ba12	297	else
8288f496	298	bi->flags &= ~BLK_INTEGRITY_VERIFY;
7ba1ba12 MP	299
	300	return count;
	301	}
	302
8288f496	303	static ssize_t integrity_verify_show(struct blk_integrity bi, char page)
7ba1ba12	304	{
8288f496	305	return sprintf(page, "%d\n", (bi->flags & BLK_INTEGRITY_VERIFY) != 0);
7ba1ba12 MP	306	}
7ba1ba12 MP	307
8288f496 MP	308	static ssize_t integrity_generate_store(struct blk_integrity *bi,
8288f496 MP	309	const char *page, size_t count)
7ba1ba12 MP	310	{
	311	char p = (char ) page;
	312	unsigned long val = simple_strtoul(p, &p, 10);
	313
	314	if (val)
8288f496	315	bi->flags \|= BLK_INTEGRITY_GENERATE;
7ba1ba12	316	else
8288f496	317	bi->flags &= ~BLK_INTEGRITY_GENERATE;
7ba1ba12 MP	318
	319	return count;
	320	}
	321
8288f496	322	static ssize_t integrity_generate_show(struct blk_integrity bi, char page)
7ba1ba12	323	{
8288f496	324	return sprintf(page, "%d\n", (bi->flags & BLK_INTEGRITY_GENERATE) != 0);
7ba1ba12 MP	325	}
7ba1ba12 MP	326
3aec2f41 MP	327	static ssize_t integrity_device_show(struct blk_integrity bi, char page)
	328	{
	329	return sprintf(page, "%u\n",
	330	(bi->flags & BLK_INTEGRITY_DEVICE_CAPABLE) != 0);
	331	}
	332
7ba1ba12 MP	333	static struct integrity_sysfs_entry integrity_format_entry = {
	334	.attr = { .name = "format", .mode = S_IRUGO },
	335	.show = integrity_format_show,
	336	};
	337
	338	static struct integrity_sysfs_entry integrity_tag_size_entry = {
	339	.attr = { .name = "tag_size", .mode = S_IRUGO },
	340	.show = integrity_tag_size_show,
	341	};
	342
8288f496	343	static struct integrity_sysfs_entry integrity_verify_entry = {
7ba1ba12	344	.attr = { .name = "read_verify", .mode = S_IRUGO \| S_IWUSR },
8288f496 MP	345	.show = integrity_verify_show,
8288f496 MP	346	.store = integrity_verify_store,
7ba1ba12 MP	347	};
7ba1ba12 MP	348
8288f496	349	static struct integrity_sysfs_entry integrity_generate_entry = {
7ba1ba12	350	.attr = { .name = "write_generate", .mode = S_IRUGO \| S_IWUSR },
8288f496 MP	351	.show = integrity_generate_show,
8288f496 MP	352	.store = integrity_generate_store,
7ba1ba12 MP	353	};
7ba1ba12 MP	354
3aec2f41 MP	355	static struct integrity_sysfs_entry integrity_device_entry = {
	356	.attr = { .name = "device_is_integrity_capable", .mode = S_IRUGO },
	357	.show = integrity_device_show,
	358	};
	359
7ba1ba12 MP	360	static struct attribute *integrity_attrs[] = {
	361	&integrity_format_entry.attr,
	362	&integrity_tag_size_entry.attr,
8288f496 MP	363	&integrity_verify_entry.attr,
8288f496 MP	364	&integrity_generate_entry.attr,
3aec2f41	365	&integrity_device_entry.attr,
7ba1ba12 MP	366	NULL,
	367	};
	368
52cf25d0	369	static const struct sysfs_ops integrity_ops = {
7ba1ba12 MP	370	.show = &integrity_attr_show,
	371	.store = &integrity_attr_store,
	372	};
	373
	374	static int __init blk_dev_integrity_init(void)
	375	{
	376	integrity_cachep = kmem_cache_create("blkdev_integrity",
	377	sizeof(struct blk_integrity),
	378	0, SLAB_PANIC, NULL);
	379	return 0;
	380	}
	381	subsys_initcall(blk_dev_integrity_init);
	382
	383	static void blk_integrity_release(struct kobject *kobj)
	384	{
	385	struct blk_integrity *bi =
	386	container_of(kobj, struct blk_integrity, kobj);
	387
	388	kmem_cache_free(integrity_cachep, bi);
	389	}
	390
	391	static struct kobj_type integrity_ktype = {
	392	.default_attrs = integrity_attrs,
	393	.sysfs_ops = &integrity_ops,
	394	.release = blk_integrity_release,
	395	};
	396
a63a5cf8 MS	397	bool blk_integrity_is_initialized(struct gendisk *disk)
	398	{
	399	struct blk_integrity *bi = blk_get_integrity(disk);
	400
	401	return (bi && bi->name && strcmp(bi->name, bi_unsupported_name) != 0);
	402	}
	403	EXPORT_SYMBOL(blk_integrity_is_initialized);
	404
7ba1ba12 MP	405	/**
	406	* blk_integrity_register - Register a gendisk as being integrity-capable
	407	* @disk: struct gendisk pointer to make integrity-aware
32231638	408	* @template: optional integrity profile to register
7ba1ba12 MP	409	*
	410	* Description: When a device needs to advertise itself as being able
	411	* to send/receive integrity metadata it must use this function to
	412	* register the capability with the block layer. The template is a
	413	* blk_integrity struct with values appropriate for the underlying
32231638 MP	414	* hardware. If template is NULL the new profile is allocated but
32231638 MP	415	* not filled out. See Documentation/block/data-integrity.txt.
7ba1ba12 MP	416	*/
	417	int blk_integrity_register(struct gendisk disk, struct blk_integrity template)
	418	{
	419	struct blk_integrity *bi;
	420
	421	BUG_ON(disk == NULL);
7ba1ba12 MP	422
7ba1ba12 MP	423	if (disk->integrity == NULL) {
b984679e	424	bi = kmem_cache_alloc(integrity_cachep,
32231638	425	GFP_KERNEL \| __GFP_ZERO);
7ba1ba12 MP	426	if (!bi)
	427	return -1;
	428
	429	if (kobject_init_and_add(&bi->kobj, &integrity_ktype,
ed9e1982 TH	430	&disk_to_dev(disk)->kobj,
ed9e1982 TH	431	"%s", "integrity")) {
7ba1ba12 MP	432	kmem_cache_free(integrity_cachep, bi);
	433	return -1;
	434	}
	435
	436	kobject_uevent(&bi->kobj, KOBJ_ADD);
	437
8288f496	438	bi->flags \|= BLK_INTEGRITY_VERIFY \| BLK_INTEGRITY_GENERATE;
3be91c4a	439	bi->interval = queue_logical_block_size(disk->queue);
7ba1ba12 MP	440	disk->integrity = bi;
	441	} else
	442	bi = disk->integrity;
	443
	444	/* Use the provided profile as template */
32231638 MP	445	if (template != NULL) {
	446	bi->name = template->name;
	447	bi->generate_fn = template->generate_fn;
	448	bi->verify_fn = template->verify_fn;
	449	bi->tuple_size = template->tuple_size;
32231638	450	bi->tag_size = template->tag_size;
8288f496	451	bi->flags \|= template->flags;
32231638	452	} else
a63a5cf8	453	bi->name = bi_unsupported_name;
7ba1ba12	454
7d311cda DW	455	disk->queue->backing_dev_info.capabilities \|= BDI_CAP_STABLE_WRITES;
7d311cda DW	456
7ba1ba12 MP	457	return 0;
	458	}
	459	EXPORT_SYMBOL(blk_integrity_register);
	460
	461	/**
	462	* blk_integrity_unregister - Remove block integrity profile
	463	* @disk: disk whose integrity profile to deallocate
	464	*
	465	* Description: This function frees all memory used by the block
	466	* integrity profile. To be called at device teardown.
	467	*/
	468	void blk_integrity_unregister(struct gendisk *disk)
	469	{
	470	struct blk_integrity *bi;
	471
	472	if (!disk \|\| !disk->integrity)
	473	return;
	474
7d311cda DW	475	disk->queue->backing_dev_info.capabilities &= ~BDI_CAP_STABLE_WRITES;
7d311cda DW	476
7ba1ba12 MP	477	bi = disk->integrity;
	478
	479	kobject_uevent(&bi->kobj, KOBJ_REMOVE);
	480	kobject_del(&bi->kobj);
3839e4b2	481	kobject_put(&bi->kobj);
0c032ab8	482	disk->integrity = NULL;
7ba1ba12 MP	483	}
7ba1ba12 MP	484	EXPORT_SYMBOL(blk_integrity_unregister);