aboutsummaryrefslogtreecommitdiffstats
path: root/fs/bio-integrity.c
blob: a8f4cc679983dc9317d0a62bd4d4d86c49ca39ff (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
/*
 * bio-integrity.c - bio data integrity extensions
 *
 * Copyright (C) 2007, 2008, 2009 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/workqueue.h>
#include <linux/slab.h>

struct integrity_slab {
	struct kmem_cache *slab;
	unsigned short nr_vecs;
	char name[8];
};

#define IS(x) { .nr_vecs = x, .name = "bip-"__stringify(x) }
struct integrity_slab bip_slab[BIOVEC_NR_POOLS] __read_mostly = {
	IS(1), IS(4), IS(16), IS(64), IS(128), IS(BIO_MAX_PAGES),
};
#undef IS

static struct workqueue_struct *kintegrityd_wq;

static inline unsigned int vecs_to_idx(unsigned int nr)
{
	switch (nr) {
	case 1:
		return 0;
	case 2 ... 4:
		return 1;
	case 5 ... 16:
		return 2;
	case 17 ... 64:
		return 3;
	case 65 ... 128:
		return 4;
	case 129 ... BIO_MAX_PAGES:
		return 5;
	default:
		BUG();
	}
}

static inline int use_bip_pool(unsigned int idx)
{
	if (idx == BIOVEC_MAX_IDX)
		return 1;

	return 0;
}

/**
 * bio_integrity_alloc_bioset - Allocate integrity payload and attach it to bio
 * @bio:	bio to attach integrity metadata to
 * @gfp_mask:	Memory allocation mask
 * @nr_vecs:	Number of integrity metadata scatter-gather elements
 * @bs:		bio_set to allocate from
 *
 * Description: This function prepares a bio for attaching integrity
 * metadata.  nr_vecs specifies the maximum number of pages containing
 * integrity metadata that can be attached.
 */
struct bio_integrity_payload *bio_integrity_alloc_bioset(struct bio *bio,
							 gfp_t gfp_mask,
							 unsigned int nr_vecs,
							 struct bio_set *bs)
{
	struct bio_integrity_payload *bip;
	unsigned int idx = vecs_to_idx(nr_vecs);

	BUG_ON(bio == NULL);
	bip = NULL;

	/* Lower order allocations come straight from slab */
	if (!use_bip_pool(idx))
		bip = kmem_cache_alloc(bip_slab[idx].slab, gfp_mask);

	/* Use mempool if lower order alloc failed or max vecs were requested */
	if (bip == NULL) {
		idx = BIOVEC_MAX_IDX;  /* so we free the payload properly later */
		bip = mempool_alloc(bs->bio_integrity_pool, gfp_mask);

		if (unlikely(bip == NULL)) {
			printk(KERN_ERR "%s: could not alloc bip\n", __func__);
			return NULL;
		}
	}

	memset(bip, 0, sizeof(*bip));

	bip->bip_slab = idx;
	bip->bip_bio = bio;
	bio->bi_integrity = bip;

	return bip;
}
EXPORT_SYMBOL(bio_integrity_alloc_bioset);

/**
 * bio_integrity_alloc - Allocate integrity payload and attach it to bio
 * @bio:	bio to attach integrity metadata to
 * @gfp_mask:	Memory allocation mask
 * @nr_vecs:	Number of integrity metadata scatter-gather elements
 *
 * Description: This function prepares a bio for attaching integrity
 * metadata.  nr_vecs specifies the maximum number of pages containing
 * integrity metadata that can be attached.
 */
struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
						  gfp_t gfp_mask,
						  unsigned int nr_vecs)
{
	return bio_integrity_alloc_bioset(bio, gfp_mask, nr_vecs, fs_bio_set);
}
EXPORT_SYMBOL(bio_integrity_alloc);

/**
 * bio_integrity_free - Free bio integrity payload
 * @bio:	bio containing bip to be freed
 * @bs:		bio_set this bio was allocated from
 *
 * Description: Used to free the integrity portion of a bio. Usually
 * called from bio_free().
 */
void bio_integrity_free(struct bio *bio, struct bio_set *bs)
{
	struct bio_integrity_payload *bip = bio->bi_integrity;

	BUG_ON(bip == NULL);

	/* A cloned bio doesn't own the integrity metadata */
	if (!bio_flagged(bio, BIO_CLONED) && !bio_flagged(bio, BIO_FS_INTEGRITY)
	    && bip->bip_buf != NULL)
		kfree(bip->bip_buf);

	if (use_bip_pool(bip->bip_slab))
		mempool_free(bip, bs->bio_integrity_pool);
	else
		kmem_cache_free(bip_slab[bip->bip_slab].slab, bip);

	bio->bi_integrity = NULL;
}
EXPORT_SYMBOL(bio_integrity_free);

/**
 * bio_integrity_add_page - Attach integrity metadata
 * @bio:	bio to update
 * @page:	page containing integrity metadata
 * @len:	number of bytes of integrity metadata in page
 * @offset:	start offset within page
 *
 * Description: Attach a page containing integrity metadata to bio.
 */
int bio_integrity_add_page(struct bio *bio, struct page *page,
			   unsigned int len, unsigned int offset)
{
	struct bio_integrity_payload *bip = bio->bi_integrity;
	struct bio_vec *iv;

	if (bip->bip_vcnt >= bvec_nr_vecs(bip->bip_slab)) {
		printk(KERN_ERR "%s: bip_vec full\n", __func__);
		return 0;
	}

	iv = bip_vec_idx(bip, bip->bip_vcnt);
	BUG_ON(iv == NULL);

	iv->bv_page = page;
	iv->bv_len = len;
	iv->bv_offset = offset;
	bip->bip_vcnt++;

	return len;
}
EXPORT_SYMBOL(bio_integrity_add_page);

static int bdev_integrity_enabled(struct block_device *bdev, int rw)
{
	struct blk_integrity *bi = bdev_get_integrity(bdev);

	if (bi == NULL)
		return 0;

	if (rw == READ && bi->verify_fn != NULL &&
	    (bi->flags & INTEGRITY_FLAG_READ))
		return 1;

	if (rw == WRITE && bi->generate_fn != NULL &&
	    (bi->flags & INTEGRITY_FLAG_WRITE))
		return 1;

	return 0;
}

/**
 * bio_integrity_enabled - Check whether integrity can be passed
 * @bio:	bio to check
 *
 * Description: Determines whether bio_integrity_prep() can be called
 * on this bio or not.	bio data direction and target device must be
 * set prior to calling.  The functions honors the write_generate and
 * read_verify flags in sysfs.
 */
int bio_integrity_enabled(struct bio *bio)
{
	/* Already protected? */
	if (bio_integrity(bio))
		return 0;

	return bdev_integrity_enabled(bio->bi_bdev, bio_data_dir(bio));
}
EXPORT_SYMBOL(bio_integrity_enabled);

/**
 * bio_integrity_hw_sectors - Convert 512b sectors to hardware ditto
 * @bi:		blk_integrity profile for device
 * @sectors:	Number of 512 sectors to convert
 *
 * Description: The block layer calculates everything in 512 byte
 * sectors but integrity metadata is done in terms of the hardware
 * sector size of the storage device.  Convert the block layer sectors
 * to physical sectors.
 */
static inline unsigned int bio_integrity_hw_sectors(struct blk_integrity *bi,
						    unsigned int sectors)
{
	/* At this point there are only 512b or 4096b DIF/EPP devices */
	if (bi->sector_size == 4096)
		return sectors >>= 3;

	return sectors;
}

/**
 * bio_integrity_tag_size - Retrieve integrity tag space
 * @bio:	bio to inspect
 *
 * Description: Returns the maximum number of tag bytes that can be
 * attached to this bio. Filesystems can use this to determine how
 * much metadata to attach to an I/O.
 */
unsigned int bio_integrity_tag_size(struct bio *bio)
{
	struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);

	BUG_ON(bio->bi_size == 0);

	return bi->tag_size * (bio->bi_size / bi->sector_size);
}
EXPORT_SYMBOL(bio_integrity_tag_size);

int bio_integrity_tag(struct bio *bio, void *tag_buf, unsigned int len, int set)
{
	struct bio_integrity_payload *bip = bio->bi_integrity;
	struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
	unsigned int nr_sectors;

	BUG_ON(bip->bip_buf == NULL);

	if (bi->tag_size == 0)
		return -1;

	nr_sectors = bio_integrity_hw_sectors(bi,
					DIV_ROUND_UP(len, bi->tag_size));

	if (nr_sectors * bi->tuple_size > bip->bip_size) {
		printk(KERN_ERR "%s: tag too big for bio: %u > %u\n",
		       __func__, nr_sectors * bi->tuple_size, bip->bip_size);
		return -1;
	}

	if (set)
		bi->set_tag_fn(bip->bip_buf, tag_buf, nr_sectors);
	else
		bi->get_tag_fn(bip->bip_buf, tag_buf, nr_sectors);

	return 0;
}

/**
 * bio_integrity_set_tag - Attach a tag buffer to a bio
 * @bio:	bio to attach buffer to
 * @tag_buf:	Pointer to a buffer containing tag data
 * @len:	Length of the included buffer
 *
 * Description: Use this function to tag a bio by leveraging the extra
 * space provided by devices formatted with integrity protection.  The
 * size of the integrity buffer must be <= to the size reported by
 * bio_integrity_tag_size().
 */
int bio_integrity_set_tag(struct bio *bio, void *tag_buf, unsigned int len)
{
	BUG_ON(bio_data_dir(bio) != WRITE);

	return bio_integrity_tag(bio, tag_buf, len, 1);
}
EXPORT_SYMBOL(bio_integrity_set_tag);

/**
 * bio_integrity_get_tag - Retrieve a tag buffer from a bio
 * @bio:	bio to retrieve buffer from
 * @tag_buf:	Pointer to a buffer for the tag data
 * @len:	Length of the target buffer
 *
 * Description: Use this function to retrieve the tag buffer from a
 * completed I/O. The size of the integrity buffer must be <= to the
 * size reported by bio_integrity_tag_size().
 */
int bio_integrity_get_tag(struct bio *bio, void *tag_buf, unsigned int len)
{
	BUG_ON(bio_data_dir(bio) != READ);

	return bio_integrity_tag(bio, tag_buf, len, 0);
}
EXPORT_SYMBOL(bio_integrity_get_tag);

/**
 * bio_integrity_generate - Generate integrity metadata for a bio
 * @bio:	bio to generate integrity metadata for
 *
 * Description: Generates integrity metadata for a bio by calling the
 * block device's generation callback function.  The bio must have a
 * bip attached with enough room to accommodate the generated
 * integrity metadata.
 */
static void bio_integrity_generate(struct bio *bio)
{
	struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
	struct blk_integrity_exchg bix;
	struct bio_vec *bv;
	sector_t sector = bio->bi_sector;
	unsigned int i, sectors, total;
	void *prot_buf = bio->bi_integrity->bip_buf;

	total = 0;
	bix.disk_name = bio->bi_bdev->bd_disk->disk_name;
	bix.sector_size = bi->sector_size;

	bio_for_each_segment(bv, bio, i) {
		void *kaddr = kmap_atomic(bv->bv_page, KM_USER0);
		bix.data_buf = kaddr + bv->bv_offset;
		bix.data_size = bv->bv_len;
		bix.prot_buf = prot_buf;
		bix.sector = sector;

		bi->generate_fn(&bix);

		sectors = bv->bv_len / bi->sector_size;
		sector += sectors;
		prot_buf += sectors * bi->tuple_size;
		total += sectors * bi->tuple_size;
		BUG_ON(total > bio->bi_integrity->bip_size);

		kunmap_atomic(kaddr, KM_USER0);
	}
}

static inline unsigned short blk_integrity_tuple_size(struct blk_integrity *bi)
{
	if (bi)
		return bi->tuple_size;

	return 0;
}

/**
 * bio_integrity_prep - Prepare bio for integrity I/O
 * @bio:	bio to prepare
 *
 * Description: Allocates a buffer for integrity metadata, maps the
 * pages and attaches them to a bio.  The bio must have data
 * direction, target device and start sector set priot to calling.  In
 * the WRITE case, integrity metadata will be generated using the
 * block device's integrity function.  In the READ case, the buffer
 * will be prepared for DMA and a suitable end_io handler set up.
 */
int bio_integrity_prep(struct bio *bio)
{
	struct bio_integrity_payload *bip;
	struct blk_integrity *bi;
	struct request_queue *q;
	void *buf;
	unsigned long start, end;
	unsigned int len, nr_pages;
	unsigned int bytes, offset, i;
	unsigned int sectors;

	bi = bdev_get_integrity(bio->bi_bdev);
	q = bdev_get_queue(bio->bi_bdev);
	BUG_ON(bi == NULL);
	BUG_ON(bio_integrity(bio));

	sectors = bio_integrity_hw_sectors(bi, bio_sectors(bio));

	/* Allocate kernel buffer for protection data */
	len = sectors * blk_integrity_tuple_size(bi);
	buf = kmalloc(len, GFP_NOIO | q->bounce_gfp);
	if (unlikely(buf == NULL)) {
		printk(KERN_ERR "could not allocate integrity buffer\n");
		return -EIO;
	}

	end = (((unsigned long) buf) + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
	start = ((unsigned long) buf) >> PAGE_SHIFT;
	nr_pages = end - start;

	/* Allocate bio integrity payload and integrity vectors */
	bip = bio_integrity_alloc(bio, GFP_NOIO, nr_pages);
	if (unlikely(bip == NULL)) {
		printk(KERN_ERR "could not allocate data integrity bioset\n");
		kfree(buf);
		return -EIO;
	}

	bip->bip_buf = buf;
	bip->bip_size = len;
	bip->bip_sector = bio->bi_sector;

	/* Map it */
	offset = offset_in_page(buf);
	for (i = 0 ; i < nr_pages ; i++) {
		int ret;
		bytes = PAGE_SIZE - offset;

		if (len <= 0)
			break;

		if (bytes > len)
			bytes = len;

		ret = bio_integrity_add_page(bio, virt_to_page(buf),
					     bytes, offset);

		if (ret == 0)
			return 0;

		if (ret < bytes)
			break;

		buf += bytes;
		len -= bytes;
		offset = 0;
	}

	/* Install custom I/O completion handler if read verify is enabled */
	if (bio_data_dir(bio) == READ) {
		bip->bip_end_io = bio->bi_end_io;
		bio->bi_end_io = bio_integrity_endio;
	}

	/* Auto-generate integrity metadata if this is a write */
	if (bio_data_dir(bio) == WRITE)
		bio_integrity_generate(bio);

	return 0;
}
EXPORT_SYMBOL(bio_integrity_prep);

/**
 * bio_integrity_verify - Verify integrity metadata for a bio
 * @bio:	bio to verify
 *
 * Description: This function is called to verify the integrity of a
 * bio.	 The data in the bio io_vec is compared to the integrity
 * metadata returned by the HBA.
 */
static int bio_integrity_verify(struct bio *bio)
{
	struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
	struct blk_integrity_exchg bix;
	struct bio_vec *bv;
	sector_t sector = bio->bi_integrity->bip_sector;
	unsigned int i, sectors, total, ret;
	void *prot_buf = bio->bi_integrity->bip_buf;

	ret = total = 0;
	bix.disk_name = bio->bi_bdev->bd_disk->disk_name;
	bix.sector_size = bi->sector_size;

	bio_for_each_segment(bv, bio, i) {
		void *kaddr = kmap_atomic(bv->bv_page, KM_USER0);
		bix.data_buf = kaddr + bv->bv_offset;
		bix.data_size = bv->bv_len;
		bix.prot_buf = prot_buf;
		bix.sector = sector;

		ret = bi->verify_fn(&bix);

		if (ret) {
			kunmap_atomic(kaddr, KM_USER0);
			return ret;
		}

		sectors = bv->bv_len / bi->sector_size;
		sector += sectors;
		prot_buf += sectors * bi->tuple_size;
		total += sectors * bi->tuple_size;
		BUG_ON(total > bio->bi_integrity->bip_size);

		kunmap_atomic(kaddr, KM_USER0);
	}

	return ret;
}

/**
 * bio_integrity_verify_fn - Integrity I/O completion worker
 * @work:	Work struct stored in bio to be verified
 *
 * Description: This workqueue function is called to complete a READ
 * request.  The function verifies the transferred integrity metadata
 * and then calls the original bio end_io function.
 */
static void bio_integrity_verify_fn(struct work_struct *work)
{
	struct bio_integrity_payload *bip =
		container_of(work, struct bio_integrity_payload, bip_work);
	struct bio *bio = bip->bip_bio;
	int error;

	error = bio_integrity_verify(bio);

	/* Restore original bio completion handler */
	bio->bi_end_io = bip->bip_end_io;
	bio_endio(bio, error);
}

/**
 * bio_integrity_endio - Integrity I/O completion function
 * @bio:	Protected bio
 * @error:	Pointer to errno
 *
 * Description: Completion for integrity I/O
 *
 * Normally I/O completion is done in interrupt context.  However,
 * verifying I/O integrity is a time-consuming task which must be run
 * in process context.	This function postpones completion
 * accordingly.
 */
void bio_integrity_endio(struct bio *bio, int error)
{
	struct bio_integrity_payload *bip = bio->bi_integrity;

	BUG_ON(bip->bip_bio != bio);

	/* In case of an I/O error there is no point in verifying the
	 * integrity metadata.  Restore original bio end_io handler
	 * and run it.
	 */
	if (error) {
		bio->bi_end_io = bip->bip_end_io;
		bio_endio(bio, error);

		return;
	}

	INIT_WORK(&bip->bip_work, bio_integrity_verify_fn);
	queue_work(kintegrityd_wq, &bip->bip_work);
}
EXPORT_SYMBOL(bio_integrity_endio);

/**
 * bio_integrity_mark_head - Advance bip_vec skip bytes
 * @bip:	Integrity vector to advance
 * @skip:	Number of bytes to advance it
 */
void bio_integrity_mark_head(struct bio_integrity_payload *bip,
			     unsigned int skip)
{
	struct bio_vec *iv;
	unsigned int i;

	bip_for_each_vec(iv, bip, i) {
		if (skip == 0) {
			bip->bip_idx = i;
			return;
		} else if (skip >= iv->bv_len) {
			skip -= iv->bv_len;
		} else { /* skip < iv->bv_len) */
			iv->bv_offset += skip;
			iv->bv_len -= skip;
			bip->bip_idx = i;
			return;
		}
	}
}

/**
 * bio_integrity_mark_tail - Truncate bip_vec to be len bytes long
 * @bip:	Integrity vector to truncate
 * @len:	New length of integrity vector
 */
void bio_integrity_mark_tail(struct bio_integrity_payload *bip,
			     unsigned int len)
{
	struct bio_vec *iv;
	unsigned int i;

	bip_for_each_vec(iv, bip, i) {
		if (len == 0) {
			bip->bip_vcnt = i;
			return;
		} else if (len >= iv->bv_len) {
			len -= iv->bv_len;
		} else { /* len < iv->bv_len) */
			iv->bv_len = len;
			len = 0;
		}
	}
}

/**
 * bio_integrity_advance - Advance integrity vector
 * @bio:	bio whose integrity vector to update
 * @bytes_done:	number of data bytes that have been completed
 *
 * Description: This function calculates how many integrity bytes the
 * number of completed data bytes correspond to and advances the
 * integrity vector accordingly.
 */
void bio_integrity_advance(struct bio *bio, unsigned int bytes_done)
{
	struct bio_integrity_payload *bip = bio->bi_integrity;
	struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
	unsigned int nr_sectors;

	BUG_ON(bip == NULL);
	BUG_ON(bi == NULL);

	nr_sectors = bio_integrity_hw_sectors(bi, bytes_done >> 9);
	bio_integrity_mark_head(bip, nr_sectors * bi->tuple_size);
}
EXPORT_SYMBOL(bio_integrity_advance);

/**
 * bio_integrity_trim - Trim integrity vector
 * @bio:	bio whose integrity vector to update
 * @offset:	offset to first data sector
 * @sectors:	number of data sectors
 *
 * Description: Used to trim the integrity vector in a cloned bio.
 * The ivec will be advanced corresponding to 'offset' data sectors
 * and the length will be truncated corresponding to 'len' data
 * sectors.
 */
void bio_integrity_trim(struct bio *bio, unsigned int offset,
			unsigned int sectors)
{
	struct bio_integrity_payload *bip = bio->bi_integrity;
	struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
	unsigned int nr_sectors;

	BUG_ON(bip == NULL);
	BUG_ON(bi == NULL);
	BUG_ON(!bio_flagged(bio, BIO_CLONED));

	nr_sectors = bio_integrity_hw_sectors(bi, sectors);
	bip->bip_sector = bip->bip_sector + offset;
	bio_integrity_mark_head(bip, offset * bi->tuple_size);
	bio_integrity_mark_tail(bip, sectors * bi->tuple_size);
}
EXPORT_SYMBOL(bio_integrity_trim);

/**
 * bio_integrity_split - Split integrity metadata
 * @bio:	Protected bio
 * @bp:		Resulting bio_pair
 * @sectors:	Offset
 *
 * Description: Splits an integrity page into a bio_pair.
 */
void bio_integrity_split(struct bio *bio, struct bio_pair *bp, int sectors)
{
	struct blk_integrity *bi;
	struct bio_integrity_payload *bip = bio->bi_integrity;
	unsigned int nr_sectors;

	if (bio_integrity(bio) == 0)
		return;

	bi = bdev_get_integrity(bio->bi_bdev);
	BUG_ON(bi == NULL);
	BUG_ON(bip->bip_vcnt != 1);

	nr_sectors = bio_integrity_hw_sectors(bi, sectors);

	bp->bio1.bi_integrity = &bp->bip1;
	bp->bio2.bi_integrity = &bp->bip2;

	bp->iv1 = bip->bip_vec[0];
	bp->iv2 = bip->bip_vec[0];

	bp->bip1.bip_vec[0] = bp->iv1;
	bp->bip2.bip_vec[0] = bp->iv2;

	bp->iv1.bv_len = sectors * bi->tuple_size;
	bp->iv2.bv_offset += sectors * bi->tuple_size;
	bp->iv2.bv_len -= sectors * bi->tuple_size;

	bp->bip1.bip_sector = bio->bi_integrity->bip_sector;
	bp->bip2.bip_sector = bio->bi_integrity->bip_sector + nr_sectors;

	bp->bip1.bip_vcnt = bp->bip2.bip_vcnt = 1;
	bp->bip1.bip_idx = bp->bip2.bip_idx = 0;
}
EXPORT_SYMBOL(bio_integrity_split);

/**
 * bio_integrity_clone - Callback for cloning bios with integrity metadata
 * @bio:	New bio
 * @bio_src:	Original bio
 * @gfp_mask:	Memory allocation mask
 * @bs:		bio_set to allocate bip from
 *
 * Description:	Called to allocate a bip when cloning a bio
 */
int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
			gfp_t gfp_mask, struct bio_set *bs)
{
	struct bio_integrity_payload *bip_src = bio_src->bi_integrity;
	struct bio_integrity_payload *bip;

	BUG_ON(bip_src == NULL);

	bip = bio_integrity_alloc_bioset(bio, gfp_mask, bip_src->bip_vcnt, bs);

	if (bip == NULL)
		return -EIO;

	memcpy(bip->bip_vec, bip_src->bip_vec,
	       bip_src->bip_vcnt * sizeof(struct bio_vec));

	bip->bip_sector = bip_src->bip_sector;
	bip->bip_vcnt = bip_src->bip_vcnt;
	bip->bip_idx = bip_src->bip_idx;

	return 0;
}
EXPORT_SYMBOL(bio_integrity_clone);

int bioset_integrity_create(struct bio_set *bs, int pool_size)
{
	unsigned int max_slab = vecs_to_idx(BIO_MAX_PAGES);

	bs->bio_integrity_pool =
		mempool_create_slab_pool(pool_size, bip_slab[max_slab].slab);

	if (!bs->bio_integrity_pool)
		return -1;

	return 0;
}
EXPORT_SYMBOL(bioset_integrity_create);

void bioset_integrity_free(struct bio_set *bs)
{
	if (bs->bio_integrity_pool)
		mempool_destroy(bs->bio_integrity_pool);
}
EXPORT_SYMBOL(bioset_integrity_free);

void __init bio_integrity_init(void)
{
	unsigned int i;

	kintegrityd_wq = create_workqueue("kintegrityd");
	if (!kintegrityd_wq)
		panic("Failed to create kintegrityd\n");

	for (i = 0 ; i < BIOVEC_NR_POOLS ; i++) {
		unsigned int size;

		size = sizeof(struct bio_integrity_payload)
			+ bip_slab[i].nr_vecs * sizeof(struct bio_vec);

		bip_slab[i].slab =
			kmem_cache_create(bip_slab[i].name, size, 0,
					  SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
	}
}