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1 /*
2  * bio-integrity.c - bio 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/workqueue.h>
27 
28 static struct kmem_cache *bio_integrity_slab __read_mostly;
29 static struct workqueue_struct *kintegrityd_wq;
30 
31 /**
32  * bio_integrity_alloc_bioset - Allocate integrity payload and attach it to bio
33  * @bio:	bio to attach integrity metadata to
34  * @gfp_mask:	Memory allocation mask
35  * @nr_vecs:	Number of integrity metadata scatter-gather elements
36  * @bs:		bio_set to allocate from
37  *
38  * Description: This function prepares a bio for attaching integrity
39  * metadata.  nr_vecs specifies the maximum number of pages containing
40  * integrity metadata that can be attached.
41  */
bio_integrity_alloc_bioset(struct bio * bio,gfp_t gfp_mask,unsigned int nr_vecs,struct bio_set * bs)42 struct bio_integrity_payload *bio_integrity_alloc_bioset(struct bio *bio,
43 							 gfp_t gfp_mask,
44 							 unsigned int nr_vecs,
45 							 struct bio_set *bs)
46 {
47 	struct bio_integrity_payload *bip;
48 	struct bio_vec *iv;
49 	unsigned long idx;
50 
51 	BUG_ON(bio == NULL);
52 
53 	bip = mempool_alloc(bs->bio_integrity_pool, gfp_mask);
54 	if (unlikely(bip == NULL)) {
55 		printk(KERN_ERR "%s: could not alloc bip\n", __func__);
56 		return NULL;
57 	}
58 
59 	memset(bip, 0, sizeof(*bip));
60 
61 	iv = bvec_alloc_bs(gfp_mask, nr_vecs, &idx, bs);
62 	if (unlikely(iv == NULL)) {
63 		printk(KERN_ERR "%s: could not alloc bip_vec\n", __func__);
64 		mempool_free(bip, bs->bio_integrity_pool);
65 		return NULL;
66 	}
67 
68 	bip->bip_pool = idx;
69 	bip->bip_vec = iv;
70 	bip->bip_bio = bio;
71 	bio->bi_integrity = bip;
72 
73 	return bip;
74 }
75 EXPORT_SYMBOL(bio_integrity_alloc_bioset);
76 
77 /**
78  * bio_integrity_alloc - Allocate integrity payload and attach it to bio
79  * @bio:	bio to attach integrity metadata to
80  * @gfp_mask:	Memory allocation mask
81  * @nr_vecs:	Number of integrity metadata scatter-gather elements
82  *
83  * Description: This function prepares a bio for attaching integrity
84  * metadata.  nr_vecs specifies the maximum number of pages containing
85  * integrity metadata that can be attached.
86  */
bio_integrity_alloc(struct bio * bio,gfp_t gfp_mask,unsigned int nr_vecs)87 struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
88 						  gfp_t gfp_mask,
89 						  unsigned int nr_vecs)
90 {
91 	return bio_integrity_alloc_bioset(bio, gfp_mask, nr_vecs, fs_bio_set);
92 }
93 EXPORT_SYMBOL(bio_integrity_alloc);
94 
95 /**
96  * bio_integrity_free - Free bio integrity payload
97  * @bio:	bio containing bip to be freed
98  * @bs:		bio_set this bio was allocated from
99  *
100  * Description: Used to free the integrity portion of a bio. Usually
101  * called from bio_free().
102  */
bio_integrity_free(struct bio * bio,struct bio_set * bs)103 void bio_integrity_free(struct bio *bio, struct bio_set *bs)
104 {
105 	struct bio_integrity_payload *bip = bio->bi_integrity;
106 
107 	BUG_ON(bip == NULL);
108 
109 	/* A cloned bio doesn't own the integrity metadata */
110 	if (!bio_flagged(bio, BIO_CLONED) && !bio_flagged(bio, BIO_FS_INTEGRITY)
111 	    && bip->bip_buf != NULL)
112 		kfree(bip->bip_buf);
113 
114 	bvec_free_bs(bs, bip->bip_vec, bip->bip_pool);
115 	mempool_free(bip, bs->bio_integrity_pool);
116 
117 	bio->bi_integrity = NULL;
118 }
119 EXPORT_SYMBOL(bio_integrity_free);
120 
121 /**
122  * bio_integrity_add_page - Attach integrity metadata
123  * @bio:	bio to update
124  * @page:	page containing integrity metadata
125  * @len:	number of bytes of integrity metadata in page
126  * @offset:	start offset within page
127  *
128  * Description: Attach a page containing integrity metadata to bio.
129  */
bio_integrity_add_page(struct bio * bio,struct page * page,unsigned int len,unsigned int offset)130 int bio_integrity_add_page(struct bio *bio, struct page *page,
131 			   unsigned int len, unsigned int offset)
132 {
133 	struct bio_integrity_payload *bip = bio->bi_integrity;
134 	struct bio_vec *iv;
135 
136 	if (bip->bip_vcnt >= bvec_nr_vecs(bip->bip_pool)) {
137 		printk(KERN_ERR "%s: bip_vec full\n", __func__);
138 		return 0;
139 	}
140 
141 	iv = bip_vec_idx(bip, bip->bip_vcnt);
142 	BUG_ON(iv == NULL);
143 
144 	iv->bv_page = page;
145 	iv->bv_len = len;
146 	iv->bv_offset = offset;
147 	bip->bip_vcnt++;
148 
149 	return len;
150 }
151 EXPORT_SYMBOL(bio_integrity_add_page);
152 
bdev_integrity_enabled(struct block_device * bdev,int rw)153 static int bdev_integrity_enabled(struct block_device *bdev, int rw)
154 {
155 	struct blk_integrity *bi = bdev_get_integrity(bdev);
156 
157 	if (bi == NULL)
158 		return 0;
159 
160 	if (rw == READ && bi->verify_fn != NULL &&
161 	    (bi->flags & INTEGRITY_FLAG_READ))
162 		return 1;
163 
164 	if (rw == WRITE && bi->generate_fn != NULL &&
165 	    (bi->flags & INTEGRITY_FLAG_WRITE))
166 		return 1;
167 
168 	return 0;
169 }
170 
171 /**
172  * bio_integrity_enabled - Check whether integrity can be passed
173  * @bio:	bio to check
174  *
175  * Description: Determines whether bio_integrity_prep() can be called
176  * on this bio or not.	bio data direction and target device must be
177  * set prior to calling.  The functions honors the write_generate and
178  * read_verify flags in sysfs.
179  */
bio_integrity_enabled(struct bio * bio)180 int bio_integrity_enabled(struct bio *bio)
181 {
182 	/* Already protected? */
183 	if (bio_integrity(bio))
184 		return 0;
185 
186 	return bdev_integrity_enabled(bio->bi_bdev, bio_data_dir(bio));
187 }
188 EXPORT_SYMBOL(bio_integrity_enabled);
189 
190 /**
191  * bio_integrity_hw_sectors - Convert 512b sectors to hardware ditto
192  * @bi:		blk_integrity profile for device
193  * @sectors:	Number of 512 sectors to convert
194  *
195  * Description: The block layer calculates everything in 512 byte
196  * sectors but integrity metadata is done in terms of the hardware
197  * sector size of the storage device.  Convert the block layer sectors
198  * to physical sectors.
199  */
bio_integrity_hw_sectors(struct blk_integrity * bi,unsigned int sectors)200 static inline unsigned int bio_integrity_hw_sectors(struct blk_integrity *bi,
201 						    unsigned int sectors)
202 {
203 	/* At this point there are only 512b or 4096b DIF/EPP devices */
204 	if (bi->sector_size == 4096)
205 		return sectors >>= 3;
206 
207 	return sectors;
208 }
209 
210 /**
211  * bio_integrity_tag_size - Retrieve integrity tag space
212  * @bio:	bio to inspect
213  *
214  * Description: Returns the maximum number of tag bytes that can be
215  * attached to this bio. Filesystems can use this to determine how
216  * much metadata to attach to an I/O.
217  */
bio_integrity_tag_size(struct bio * bio)218 unsigned int bio_integrity_tag_size(struct bio *bio)
219 {
220 	struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
221 
222 	BUG_ON(bio->bi_size == 0);
223 
224 	return bi->tag_size * (bio->bi_size / bi->sector_size);
225 }
226 EXPORT_SYMBOL(bio_integrity_tag_size);
227 
bio_integrity_tag(struct bio * bio,void * tag_buf,unsigned int len,int set)228 int bio_integrity_tag(struct bio *bio, void *tag_buf, unsigned int len, int set)
229 {
230 	struct bio_integrity_payload *bip = bio->bi_integrity;
231 	struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
232 	unsigned int nr_sectors;
233 
234 	BUG_ON(bip->bip_buf == NULL);
235 
236 	if (bi->tag_size == 0)
237 		return -1;
238 
239 	nr_sectors = bio_integrity_hw_sectors(bi,
240 					DIV_ROUND_UP(len, bi->tag_size));
241 
242 	if (nr_sectors * bi->tuple_size > bip->bip_size) {
243 		printk(KERN_ERR "%s: tag too big for bio: %u > %u\n",
244 		       __func__, nr_sectors * bi->tuple_size, bip->bip_size);
245 		return -1;
246 	}
247 
248 	if (set)
249 		bi->set_tag_fn(bip->bip_buf, tag_buf, nr_sectors);
250 	else
251 		bi->get_tag_fn(bip->bip_buf, tag_buf, nr_sectors);
252 
253 	return 0;
254 }
255 
256 /**
257  * bio_integrity_set_tag - Attach a tag buffer to a bio
258  * @bio:	bio to attach buffer to
259  * @tag_buf:	Pointer to a buffer containing tag data
260  * @len:	Length of the included buffer
261  *
262  * Description: Use this function to tag a bio by leveraging the extra
263  * space provided by devices formatted with integrity protection.  The
264  * size of the integrity buffer must be <= to the size reported by
265  * bio_integrity_tag_size().
266  */
bio_integrity_set_tag(struct bio * bio,void * tag_buf,unsigned int len)267 int bio_integrity_set_tag(struct bio *bio, void *tag_buf, unsigned int len)
268 {
269 	BUG_ON(bio_data_dir(bio) != WRITE);
270 
271 	return bio_integrity_tag(bio, tag_buf, len, 1);
272 }
273 EXPORT_SYMBOL(bio_integrity_set_tag);
274 
275 /**
276  * bio_integrity_get_tag - Retrieve a tag buffer from a bio
277  * @bio:	bio to retrieve buffer from
278  * @tag_buf:	Pointer to a buffer for the tag data
279  * @len:	Length of the target buffer
280  *
281  * Description: Use this function to retrieve the tag buffer from a
282  * completed I/O. The size of the integrity buffer must be <= to the
283  * size reported by bio_integrity_tag_size().
284  */
bio_integrity_get_tag(struct bio * bio,void * tag_buf,unsigned int len)285 int bio_integrity_get_tag(struct bio *bio, void *tag_buf, unsigned int len)
286 {
287 	BUG_ON(bio_data_dir(bio) != READ);
288 
289 	return bio_integrity_tag(bio, tag_buf, len, 0);
290 }
291 EXPORT_SYMBOL(bio_integrity_get_tag);
292 
293 /**
294  * bio_integrity_generate - Generate integrity metadata for a bio
295  * @bio:	bio to generate integrity metadata for
296  *
297  * Description: Generates integrity metadata for a bio by calling the
298  * block device's generation callback function.  The bio must have a
299  * bip attached with enough room to accommodate the generated
300  * integrity metadata.
301  */
bio_integrity_generate(struct bio * bio)302 static void bio_integrity_generate(struct bio *bio)
303 {
304 	struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
305 	struct blk_integrity_exchg bix;
306 	struct bio_vec *bv;
307 	sector_t sector = bio->bi_sector;
308 	unsigned int i, sectors, total;
309 	void *prot_buf = bio->bi_integrity->bip_buf;
310 
311 	total = 0;
312 	bix.disk_name = bio->bi_bdev->bd_disk->disk_name;
313 	bix.sector_size = bi->sector_size;
314 
315 	bio_for_each_segment(bv, bio, i) {
316 		void *kaddr = kmap_atomic(bv->bv_page, KM_USER0);
317 		bix.data_buf = kaddr + bv->bv_offset;
318 		bix.data_size = bv->bv_len;
319 		bix.prot_buf = prot_buf;
320 		bix.sector = sector;
321 
322 		bi->generate_fn(&bix);
323 
324 		sectors = bv->bv_len / bi->sector_size;
325 		sector += sectors;
326 		prot_buf += sectors * bi->tuple_size;
327 		total += sectors * bi->tuple_size;
328 		BUG_ON(total > bio->bi_integrity->bip_size);
329 
330 		kunmap_atomic(kaddr, KM_USER0);
331 	}
332 }
333 
blk_integrity_tuple_size(struct blk_integrity * bi)334 static inline unsigned short blk_integrity_tuple_size(struct blk_integrity *bi)
335 {
336 	if (bi)
337 		return bi->tuple_size;
338 
339 	return 0;
340 }
341 
342 /**
343  * bio_integrity_prep - Prepare bio for integrity I/O
344  * @bio:	bio to prepare
345  *
346  * Description: Allocates a buffer for integrity metadata, maps the
347  * pages and attaches them to a bio.  The bio must have data
348  * direction, target device and start sector set priot to calling.  In
349  * the WRITE case, integrity metadata will be generated using the
350  * block device's integrity function.  In the READ case, the buffer
351  * will be prepared for DMA and a suitable end_io handler set up.
352  */
bio_integrity_prep(struct bio * bio)353 int bio_integrity_prep(struct bio *bio)
354 {
355 	struct bio_integrity_payload *bip;
356 	struct blk_integrity *bi;
357 	struct request_queue *q;
358 	void *buf;
359 	unsigned long start, end;
360 	unsigned int len, nr_pages;
361 	unsigned int bytes, offset, i;
362 	unsigned int sectors;
363 
364 	bi = bdev_get_integrity(bio->bi_bdev);
365 	q = bdev_get_queue(bio->bi_bdev);
366 	BUG_ON(bi == NULL);
367 	BUG_ON(bio_integrity(bio));
368 
369 	sectors = bio_integrity_hw_sectors(bi, bio_sectors(bio));
370 
371 	/* Allocate kernel buffer for protection data */
372 	len = sectors * blk_integrity_tuple_size(bi);
373 	buf = kmalloc(len, GFP_NOIO | __GFP_NOFAIL | q->bounce_gfp);
374 	if (unlikely(buf == NULL)) {
375 		printk(KERN_ERR "could not allocate integrity buffer\n");
376 		return -EIO;
377 	}
378 
379 	end = (((unsigned long) buf) + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
380 	start = ((unsigned long) buf) >> PAGE_SHIFT;
381 	nr_pages = end - start;
382 
383 	/* Allocate bio integrity payload and integrity vectors */
384 	bip = bio_integrity_alloc(bio, GFP_NOIO, nr_pages);
385 	if (unlikely(bip == NULL)) {
386 		printk(KERN_ERR "could not allocate data integrity bioset\n");
387 		kfree(buf);
388 		return -EIO;
389 	}
390 
391 	bip->bip_buf = buf;
392 	bip->bip_size = len;
393 	bip->bip_sector = bio->bi_sector;
394 
395 	/* Map it */
396 	offset = offset_in_page(buf);
397 	for (i = 0 ; i < nr_pages ; i++) {
398 		int ret;
399 		bytes = PAGE_SIZE - offset;
400 
401 		if (len <= 0)
402 			break;
403 
404 		if (bytes > len)
405 			bytes = len;
406 
407 		ret = bio_integrity_add_page(bio, virt_to_page(buf),
408 					     bytes, offset);
409 
410 		if (ret == 0)
411 			return 0;
412 
413 		if (ret < bytes)
414 			break;
415 
416 		buf += bytes;
417 		len -= bytes;
418 		offset = 0;
419 	}
420 
421 	/* Install custom I/O completion handler if read verify is enabled */
422 	if (bio_data_dir(bio) == READ) {
423 		bip->bip_end_io = bio->bi_end_io;
424 		bio->bi_end_io = bio_integrity_endio;
425 	}
426 
427 	/* Auto-generate integrity metadata if this is a write */
428 	if (bio_data_dir(bio) == WRITE)
429 		bio_integrity_generate(bio);
430 
431 	return 0;
432 }
433 EXPORT_SYMBOL(bio_integrity_prep);
434 
435 /**
436  * bio_integrity_verify - Verify integrity metadata for a bio
437  * @bio:	bio to verify
438  *
439  * Description: This function is called to verify the integrity of a
440  * bio.	 The data in the bio io_vec is compared to the integrity
441  * metadata returned by the HBA.
442  */
bio_integrity_verify(struct bio * bio)443 static int bio_integrity_verify(struct bio *bio)
444 {
445 	struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
446 	struct blk_integrity_exchg bix;
447 	struct bio_vec *bv;
448 	sector_t sector = bio->bi_integrity->bip_sector;
449 	unsigned int i, sectors, total, ret;
450 	void *prot_buf = bio->bi_integrity->bip_buf;
451 
452 	ret = total = 0;
453 	bix.disk_name = bio->bi_bdev->bd_disk->disk_name;
454 	bix.sector_size = bi->sector_size;
455 
456 	bio_for_each_segment(bv, bio, i) {
457 		void *kaddr = kmap_atomic(bv->bv_page, KM_USER0);
458 		bix.data_buf = kaddr + bv->bv_offset;
459 		bix.data_size = bv->bv_len;
460 		bix.prot_buf = prot_buf;
461 		bix.sector = sector;
462 
463 		ret = bi->verify_fn(&bix);
464 
465 		if (ret) {
466 			kunmap_atomic(kaddr, KM_USER0);
467 			return ret;
468 		}
469 
470 		sectors = bv->bv_len / bi->sector_size;
471 		sector += sectors;
472 		prot_buf += sectors * bi->tuple_size;
473 		total += sectors * bi->tuple_size;
474 		BUG_ON(total > bio->bi_integrity->bip_size);
475 
476 		kunmap_atomic(kaddr, KM_USER0);
477 	}
478 
479 	return ret;
480 }
481 
482 /**
483  * bio_integrity_verify_fn - Integrity I/O completion worker
484  * @work:	Work struct stored in bio to be verified
485  *
486  * Description: This workqueue function is called to complete a READ
487  * request.  The function verifies the transferred integrity metadata
488  * and then calls the original bio end_io function.
489  */
bio_integrity_verify_fn(struct work_struct * work)490 static void bio_integrity_verify_fn(struct work_struct *work)
491 {
492 	struct bio_integrity_payload *bip =
493 		container_of(work, struct bio_integrity_payload, bip_work);
494 	struct bio *bio = bip->bip_bio;
495 	int error;
496 
497 	error = bio_integrity_verify(bio);
498 
499 	/* Restore original bio completion handler */
500 	bio->bi_end_io = bip->bip_end_io;
501 	bio_endio(bio, error);
502 }
503 
504 /**
505  * bio_integrity_endio - Integrity I/O completion function
506  * @bio:	Protected bio
507  * @error:	Pointer to errno
508  *
509  * Description: Completion for integrity I/O
510  *
511  * Normally I/O completion is done in interrupt context.  However,
512  * verifying I/O integrity is a time-consuming task which must be run
513  * in process context.	This function postpones completion
514  * accordingly.
515  */
bio_integrity_endio(struct bio * bio,int error)516 void bio_integrity_endio(struct bio *bio, int error)
517 {
518 	struct bio_integrity_payload *bip = bio->bi_integrity;
519 
520 	BUG_ON(bip->bip_bio != bio);
521 
522 	/* In case of an I/O error there is no point in verifying the
523 	 * integrity metadata.  Restore original bio end_io handler
524 	 * and run it.
525 	 */
526 	if (error) {
527 		bio->bi_end_io = bip->bip_end_io;
528 		bio_endio(bio, error);
529 
530 		return;
531 	}
532 
533 	INIT_WORK(&bip->bip_work, bio_integrity_verify_fn);
534 	queue_work(kintegrityd_wq, &bip->bip_work);
535 }
536 EXPORT_SYMBOL(bio_integrity_endio);
537 
538 /**
539  * bio_integrity_mark_head - Advance bip_vec skip bytes
540  * @bip:	Integrity vector to advance
541  * @skip:	Number of bytes to advance it
542  */
bio_integrity_mark_head(struct bio_integrity_payload * bip,unsigned int skip)543 void bio_integrity_mark_head(struct bio_integrity_payload *bip,
544 			     unsigned int skip)
545 {
546 	struct bio_vec *iv;
547 	unsigned int i;
548 
549 	bip_for_each_vec(iv, bip, i) {
550 		if (skip == 0) {
551 			bip->bip_idx = i;
552 			return;
553 		} else if (skip >= iv->bv_len) {
554 			skip -= iv->bv_len;
555 		} else { /* skip < iv->bv_len) */
556 			iv->bv_offset += skip;
557 			iv->bv_len -= skip;
558 			bip->bip_idx = i;
559 			return;
560 		}
561 	}
562 }
563 
564 /**
565  * bio_integrity_mark_tail - Truncate bip_vec to be len bytes long
566  * @bip:	Integrity vector to truncate
567  * @len:	New length of integrity vector
568  */
bio_integrity_mark_tail(struct bio_integrity_payload * bip,unsigned int len)569 void bio_integrity_mark_tail(struct bio_integrity_payload *bip,
570 			     unsigned int len)
571 {
572 	struct bio_vec *iv;
573 	unsigned int i;
574 
575 	bip_for_each_vec(iv, bip, i) {
576 		if (len == 0) {
577 			bip->bip_vcnt = i;
578 			return;
579 		} else if (len >= iv->bv_len) {
580 			len -= iv->bv_len;
581 		} else { /* len < iv->bv_len) */
582 			iv->bv_len = len;
583 			len = 0;
584 		}
585 	}
586 }
587 
588 /**
589  * bio_integrity_advance - Advance integrity vector
590  * @bio:	bio whose integrity vector to update
591  * @bytes_done:	number of data bytes that have been completed
592  *
593  * Description: This function calculates how many integrity bytes the
594  * number of completed data bytes correspond to and advances the
595  * integrity vector accordingly.
596  */
bio_integrity_advance(struct bio * bio,unsigned int bytes_done)597 void bio_integrity_advance(struct bio *bio, unsigned int bytes_done)
598 {
599 	struct bio_integrity_payload *bip = bio->bi_integrity;
600 	struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
601 	unsigned int nr_sectors;
602 
603 	BUG_ON(bip == NULL);
604 	BUG_ON(bi == NULL);
605 
606 	nr_sectors = bio_integrity_hw_sectors(bi, bytes_done >> 9);
607 	bio_integrity_mark_head(bip, nr_sectors * bi->tuple_size);
608 }
609 EXPORT_SYMBOL(bio_integrity_advance);
610 
611 /**
612  * bio_integrity_trim - Trim integrity vector
613  * @bio:	bio whose integrity vector to update
614  * @offset:	offset to first data sector
615  * @sectors:	number of data sectors
616  *
617  * Description: Used to trim the integrity vector in a cloned bio.
618  * The ivec will be advanced corresponding to 'offset' data sectors
619  * and the length will be truncated corresponding to 'len' data
620  * sectors.
621  */
bio_integrity_trim(struct bio * bio,unsigned int offset,unsigned int sectors)622 void bio_integrity_trim(struct bio *bio, unsigned int offset,
623 			unsigned int sectors)
624 {
625 	struct bio_integrity_payload *bip = bio->bi_integrity;
626 	struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
627 	unsigned int nr_sectors;
628 
629 	BUG_ON(bip == NULL);
630 	BUG_ON(bi == NULL);
631 	BUG_ON(!bio_flagged(bio, BIO_CLONED));
632 
633 	nr_sectors = bio_integrity_hw_sectors(bi, sectors);
634 	bip->bip_sector = bip->bip_sector + offset;
635 	bio_integrity_mark_head(bip, offset * bi->tuple_size);
636 	bio_integrity_mark_tail(bip, sectors * bi->tuple_size);
637 }
638 EXPORT_SYMBOL(bio_integrity_trim);
639 
640 /**
641  * bio_integrity_split - Split integrity metadata
642  * @bio:	Protected bio
643  * @bp:		Resulting bio_pair
644  * @sectors:	Offset
645  *
646  * Description: Splits an integrity page into a bio_pair.
647  */
bio_integrity_split(struct bio * bio,struct bio_pair * bp,int sectors)648 void bio_integrity_split(struct bio *bio, struct bio_pair *bp, int sectors)
649 {
650 	struct blk_integrity *bi;
651 	struct bio_integrity_payload *bip = bio->bi_integrity;
652 	unsigned int nr_sectors;
653 
654 	if (bio_integrity(bio) == 0)
655 		return;
656 
657 	bi = bdev_get_integrity(bio->bi_bdev);
658 	BUG_ON(bi == NULL);
659 	BUG_ON(bip->bip_vcnt != 1);
660 
661 	nr_sectors = bio_integrity_hw_sectors(bi, sectors);
662 
663 	bp->bio1.bi_integrity = &bp->bip1;
664 	bp->bio2.bi_integrity = &bp->bip2;
665 
666 	bp->iv1 = bip->bip_vec[0];
667 	bp->iv2 = bip->bip_vec[0];
668 
669 	bp->bip1.bip_vec = &bp->iv1;
670 	bp->bip2.bip_vec = &bp->iv2;
671 
672 	bp->iv1.bv_len = sectors * bi->tuple_size;
673 	bp->iv2.bv_offset += sectors * bi->tuple_size;
674 	bp->iv2.bv_len -= sectors * bi->tuple_size;
675 
676 	bp->bip1.bip_sector = bio->bi_integrity->bip_sector;
677 	bp->bip2.bip_sector = bio->bi_integrity->bip_sector + nr_sectors;
678 
679 	bp->bip1.bip_vcnt = bp->bip2.bip_vcnt = 1;
680 	bp->bip1.bip_idx = bp->bip2.bip_idx = 0;
681 }
682 EXPORT_SYMBOL(bio_integrity_split);
683 
684 /**
685  * bio_integrity_clone - Callback for cloning bios with integrity metadata
686  * @bio:	New bio
687  * @bio_src:	Original bio
688  * @gfp_mask:	Memory allocation mask
689  * @bs:		bio_set to allocate bip from
690  *
691  * Description:	Called to allocate a bip when cloning a bio
692  */
bio_integrity_clone(struct bio * bio,struct bio * bio_src,gfp_t gfp_mask,struct bio_set * bs)693 int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
694 			gfp_t gfp_mask, struct bio_set *bs)
695 {
696 	struct bio_integrity_payload *bip_src = bio_src->bi_integrity;
697 	struct bio_integrity_payload *bip;
698 
699 	BUG_ON(bip_src == NULL);
700 
701 	bip = bio_integrity_alloc_bioset(bio, gfp_mask, bip_src->bip_vcnt, bs);
702 
703 	if (bip == NULL)
704 		return -EIO;
705 
706 	memcpy(bip->bip_vec, bip_src->bip_vec,
707 	       bip_src->bip_vcnt * sizeof(struct bio_vec));
708 
709 	bip->bip_sector = bip_src->bip_sector;
710 	bip->bip_vcnt = bip_src->bip_vcnt;
711 	bip->bip_idx = bip_src->bip_idx;
712 
713 	return 0;
714 }
715 EXPORT_SYMBOL(bio_integrity_clone);
716 
bioset_integrity_create(struct bio_set * bs,int pool_size)717 int bioset_integrity_create(struct bio_set *bs, int pool_size)
718 {
719 	bs->bio_integrity_pool = mempool_create_slab_pool(pool_size,
720 							  bio_integrity_slab);
721 	if (!bs->bio_integrity_pool)
722 		return -1;
723 
724 	return 0;
725 }
726 EXPORT_SYMBOL(bioset_integrity_create);
727 
bioset_integrity_free(struct bio_set * bs)728 void bioset_integrity_free(struct bio_set *bs)
729 {
730 	if (bs->bio_integrity_pool)
731 		mempool_destroy(bs->bio_integrity_pool);
732 }
733 EXPORT_SYMBOL(bioset_integrity_free);
734 
bio_integrity_init_slab(void)735 void __init bio_integrity_init_slab(void)
736 {
737 	bio_integrity_slab = KMEM_CACHE(bio_integrity_payload,
738 					SLAB_HWCACHE_ALIGN|SLAB_PANIC);
739 }
740 
integrity_init(void)741 static int __init integrity_init(void)
742 {
743 	kintegrityd_wq = create_workqueue("kintegrityd");
744 
745 	if (!kintegrityd_wq)
746 		panic("Failed to create kintegrityd\n");
747 
748 	return 0;
749 }
750 subsys_initcall(integrity_init);
751