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Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001/*
2 * bio-integrity.c - bio data integrity extensions
3 *
Martin K. Petersen7878cba2009-06-26 15:37:49 +02004 * Copyright (C) 2007, 2008, 2009 Oracle Corporation
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02005 * 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
Martin K. Petersen7878cba2009-06-26 15:37:49 +020028struct integrity_slab {
29 struct kmem_cache *slab;
30 unsigned short nr_vecs;
31 char name[8];
32};
33
34#define IS(x) { .nr_vecs = x, .name = "bip-"__stringify(x) }
35struct integrity_slab bip_slab[BIOVEC_NR_POOLS] __read_mostly = {
36 IS(1), IS(4), IS(16), IS(64), IS(128), IS(BIO_MAX_PAGES),
37};
38#undef IS
39
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +020040static struct workqueue_struct *kintegrityd_wq;
41
Martin K. Petersen7878cba2009-06-26 15:37:49 +020042static inline unsigned int vecs_to_idx(unsigned int nr)
43{
44 switch (nr) {
45 case 1:
46 return 0;
47 case 2 ... 4:
48 return 1;
49 case 5 ... 16:
50 return 2;
51 case 17 ... 64:
52 return 3;
53 case 65 ... 128:
54 return 4;
55 case 129 ... BIO_MAX_PAGES:
56 return 5;
57 default:
58 BUG();
59 }
60}
61
62static inline int use_bip_pool(unsigned int idx)
63{
Chuck Ebbert9e9432c2010-01-30 20:28:19 +010064 if (idx == BIOVEC_MAX_IDX)
Martin K. Petersen7878cba2009-06-26 15:37:49 +020065 return 1;
66
67 return 0;
68}
69
70/**
71 * bio_integrity_alloc_bioset - Allocate integrity payload and attach it to bio
72 * @bio: bio to attach integrity metadata to
73 * @gfp_mask: Memory allocation mask
74 * @nr_vecs: Number of integrity metadata scatter-gather elements
75 * @bs: bio_set to allocate from
76 *
77 * Description: This function prepares a bio for attaching integrity
78 * metadata. nr_vecs specifies the maximum number of pages containing
79 * integrity metadata that can be attached.
80 */
81struct bio_integrity_payload *bio_integrity_alloc_bioset(struct bio *bio,
82 gfp_t gfp_mask,
83 unsigned int nr_vecs,
84 struct bio_set *bs)
85{
86 struct bio_integrity_payload *bip;
87 unsigned int idx = vecs_to_idx(nr_vecs);
88
89 BUG_ON(bio == NULL);
90 bip = NULL;
91
92 /* Lower order allocations come straight from slab */
93 if (!use_bip_pool(idx))
94 bip = kmem_cache_alloc(bip_slab[idx].slab, gfp_mask);
95
96 /* Use mempool if lower order alloc failed or max vecs were requested */
97 if (bip == NULL) {
Chuck Ebbert9e9432c2010-01-30 20:28:19 +010098 idx = BIOVEC_MAX_IDX; /* so we free the payload properly later */
Martin K. Petersen7878cba2009-06-26 15:37:49 +020099 bip = mempool_alloc(bs->bio_integrity_pool, gfp_mask);
100
101 if (unlikely(bip == NULL)) {
102 printk(KERN_ERR "%s: could not alloc bip\n", __func__);
103 return NULL;
104 }
105 }
106
107 memset(bip, 0, sizeof(*bip));
108
109 bip->bip_slab = idx;
110 bip->bip_bio = bio;
111 bio->bi_integrity = bip;
112
113 return bip;
114}
115EXPORT_SYMBOL(bio_integrity_alloc_bioset);
116
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200117/**
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200118 * bio_integrity_alloc - Allocate integrity payload and attach it to bio
119 * @bio: bio to attach integrity metadata to
120 * @gfp_mask: Memory allocation mask
121 * @nr_vecs: Number of integrity metadata scatter-gather elements
122 *
123 * Description: This function prepares a bio for attaching integrity
124 * metadata. nr_vecs specifies the maximum number of pages containing
125 * integrity metadata that can be attached.
126 */
Jens Axboeb9846792008-06-17 19:05:48 +0200127struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
128 gfp_t gfp_mask,
129 unsigned int nr_vecs)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200130{
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200131 return bio_integrity_alloc_bioset(bio, gfp_mask, nr_vecs, fs_bio_set);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200132}
133EXPORT_SYMBOL(bio_integrity_alloc);
134
135/**
136 * bio_integrity_free - Free bio integrity payload
137 * @bio: bio containing bip to be freed
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200138 * @bs: bio_set this bio was allocated from
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200139 *
140 * Description: Used to free the integrity portion of a bio. Usually
141 * called from bio_free().
142 */
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200143void bio_integrity_free(struct bio *bio, struct bio_set *bs)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200144{
145 struct bio_integrity_payload *bip = bio->bi_integrity;
146
147 BUG_ON(bip == NULL);
148
149 /* A cloned bio doesn't own the integrity metadata */
Martin K. Petersen74aa8c22008-10-01 03:38:37 -0400150 if (!bio_flagged(bio, BIO_CLONED) && !bio_flagged(bio, BIO_FS_INTEGRITY)
151 && bip->bip_buf != NULL)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200152 kfree(bip->bip_buf);
153
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200154 if (use_bip_pool(bip->bip_slab))
155 mempool_free(bip, bs->bio_integrity_pool);
156 else
157 kmem_cache_free(bip_slab[bip->bip_slab].slab, bip);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200158
159 bio->bi_integrity = NULL;
160}
161EXPORT_SYMBOL(bio_integrity_free);
162
163/**
164 * bio_integrity_add_page - Attach integrity metadata
165 * @bio: bio to update
166 * @page: page containing integrity metadata
167 * @len: number of bytes of integrity metadata in page
168 * @offset: start offset within page
169 *
170 * Description: Attach a page containing integrity metadata to bio.
171 */
172int bio_integrity_add_page(struct bio *bio, struct page *page,
173 unsigned int len, unsigned int offset)
174{
175 struct bio_integrity_payload *bip = bio->bi_integrity;
176 struct bio_vec *iv;
177
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200178 if (bip->bip_vcnt >= bvec_nr_vecs(bip->bip_slab)) {
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200179 printk(KERN_ERR "%s: bip_vec full\n", __func__);
180 return 0;
181 }
182
183 iv = bip_vec_idx(bip, bip->bip_vcnt);
184 BUG_ON(iv == NULL);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200185
186 iv->bv_page = page;
187 iv->bv_len = len;
188 iv->bv_offset = offset;
189 bip->bip_vcnt++;
190
191 return len;
192}
193EXPORT_SYMBOL(bio_integrity_add_page);
194
Jens Axboe9c02f2b2008-09-18 09:31:53 -0700195static int bdev_integrity_enabled(struct block_device *bdev, int rw)
196{
197 struct blk_integrity *bi = bdev_get_integrity(bdev);
198
199 if (bi == NULL)
200 return 0;
201
202 if (rw == READ && bi->verify_fn != NULL &&
203 (bi->flags & INTEGRITY_FLAG_READ))
204 return 1;
205
206 if (rw == WRITE && bi->generate_fn != NULL &&
207 (bi->flags & INTEGRITY_FLAG_WRITE))
208 return 1;
209
210 return 0;
211}
212
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200213/**
214 * bio_integrity_enabled - Check whether integrity can be passed
215 * @bio: bio to check
216 *
217 * Description: Determines whether bio_integrity_prep() can be called
218 * on this bio or not. bio data direction and target device must be
219 * set prior to calling. The functions honors the write_generate and
220 * read_verify flags in sysfs.
221 */
222int bio_integrity_enabled(struct bio *bio)
223{
224 /* Already protected? */
225 if (bio_integrity(bio))
226 return 0;
227
228 return bdev_integrity_enabled(bio->bi_bdev, bio_data_dir(bio));
229}
230EXPORT_SYMBOL(bio_integrity_enabled);
231
232/**
233 * bio_integrity_hw_sectors - Convert 512b sectors to hardware ditto
234 * @bi: blk_integrity profile for device
235 * @sectors: Number of 512 sectors to convert
236 *
237 * Description: The block layer calculates everything in 512 byte
238 * sectors but integrity metadata is done in terms of the hardware
239 * sector size of the storage device. Convert the block layer sectors
240 * to physical sectors.
241 */
Jens Axboeb9846792008-06-17 19:05:48 +0200242static inline unsigned int bio_integrity_hw_sectors(struct blk_integrity *bi,
243 unsigned int sectors)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200244{
245 /* At this point there are only 512b or 4096b DIF/EPP devices */
246 if (bi->sector_size == 4096)
247 return sectors >>= 3;
248
249 return sectors;
250}
251
252/**
253 * bio_integrity_tag_size - Retrieve integrity tag space
254 * @bio: bio to inspect
255 *
256 * Description: Returns the maximum number of tag bytes that can be
257 * attached to this bio. Filesystems can use this to determine how
258 * much metadata to attach to an I/O.
259 */
260unsigned int bio_integrity_tag_size(struct bio *bio)
261{
262 struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
263
264 BUG_ON(bio->bi_size == 0);
265
266 return bi->tag_size * (bio->bi_size / bi->sector_size);
267}
268EXPORT_SYMBOL(bio_integrity_tag_size);
269
270int bio_integrity_tag(struct bio *bio, void *tag_buf, unsigned int len, int set)
271{
272 struct bio_integrity_payload *bip = bio->bi_integrity;
273 struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
274 unsigned int nr_sectors;
275
276 BUG_ON(bip->bip_buf == NULL);
277
278 if (bi->tag_size == 0)
279 return -1;
280
Jens Axboeb9846792008-06-17 19:05:48 +0200281 nr_sectors = bio_integrity_hw_sectors(bi,
282 DIV_ROUND_UP(len, bi->tag_size));
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200283
284 if (nr_sectors * bi->tuple_size > bip->bip_size) {
285 printk(KERN_ERR "%s: tag too big for bio: %u > %u\n",
286 __func__, nr_sectors * bi->tuple_size, bip->bip_size);
287 return -1;
288 }
289
290 if (set)
291 bi->set_tag_fn(bip->bip_buf, tag_buf, nr_sectors);
292 else
293 bi->get_tag_fn(bip->bip_buf, tag_buf, nr_sectors);
294
295 return 0;
296}
297
298/**
299 * bio_integrity_set_tag - Attach a tag buffer to a bio
300 * @bio: bio to attach buffer to
301 * @tag_buf: Pointer to a buffer containing tag data
302 * @len: Length of the included buffer
303 *
304 * Description: Use this function to tag a bio by leveraging the extra
305 * space provided by devices formatted with integrity protection. The
306 * size of the integrity buffer must be <= to the size reported by
307 * bio_integrity_tag_size().
308 */
309int bio_integrity_set_tag(struct bio *bio, void *tag_buf, unsigned int len)
310{
311 BUG_ON(bio_data_dir(bio) != WRITE);
312
313 return bio_integrity_tag(bio, tag_buf, len, 1);
314}
315EXPORT_SYMBOL(bio_integrity_set_tag);
316
317/**
318 * bio_integrity_get_tag - Retrieve a tag buffer from a bio
319 * @bio: bio to retrieve buffer from
320 * @tag_buf: Pointer to a buffer for the tag data
321 * @len: Length of the target buffer
322 *
323 * Description: Use this function to retrieve the tag buffer from a
324 * completed I/O. The size of the integrity buffer must be <= to the
325 * size reported by bio_integrity_tag_size().
326 */
327int bio_integrity_get_tag(struct bio *bio, void *tag_buf, unsigned int len)
328{
329 BUG_ON(bio_data_dir(bio) != READ);
330
331 return bio_integrity_tag(bio, tag_buf, len, 0);
332}
333EXPORT_SYMBOL(bio_integrity_get_tag);
334
335/**
336 * bio_integrity_generate - Generate integrity metadata for a bio
337 * @bio: bio to generate integrity metadata for
338 *
339 * Description: Generates integrity metadata for a bio by calling the
340 * block device's generation callback function. The bio must have a
341 * bip attached with enough room to accommodate the generated
342 * integrity metadata.
343 */
344static void bio_integrity_generate(struct bio *bio)
345{
346 struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
347 struct blk_integrity_exchg bix;
348 struct bio_vec *bv;
349 sector_t sector = bio->bi_sector;
350 unsigned int i, sectors, total;
351 void *prot_buf = bio->bi_integrity->bip_buf;
352
353 total = 0;
354 bix.disk_name = bio->bi_bdev->bd_disk->disk_name;
355 bix.sector_size = bi->sector_size;
356
357 bio_for_each_segment(bv, bio, i) {
358 void *kaddr = kmap_atomic(bv->bv_page, KM_USER0);
359 bix.data_buf = kaddr + bv->bv_offset;
360 bix.data_size = bv->bv_len;
361 bix.prot_buf = prot_buf;
362 bix.sector = sector;
363
364 bi->generate_fn(&bix);
365
366 sectors = bv->bv_len / bi->sector_size;
367 sector += sectors;
368 prot_buf += sectors * bi->tuple_size;
369 total += sectors * bi->tuple_size;
370 BUG_ON(total > bio->bi_integrity->bip_size);
371
372 kunmap_atomic(kaddr, KM_USER0);
373 }
374}
375
Jens Axboe9c02f2b2008-09-18 09:31:53 -0700376static inline unsigned short blk_integrity_tuple_size(struct blk_integrity *bi)
377{
378 if (bi)
379 return bi->tuple_size;
380
381 return 0;
382}
383
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200384/**
385 * bio_integrity_prep - Prepare bio for integrity I/O
386 * @bio: bio to prepare
387 *
388 * Description: Allocates a buffer for integrity metadata, maps the
389 * pages and attaches them to a bio. The bio must have data
390 * direction, target device and start sector set priot to calling. In
391 * the WRITE case, integrity metadata will be generated using the
392 * block device's integrity function. In the READ case, the buffer
393 * will be prepared for DMA and a suitable end_io handler set up.
394 */
395int bio_integrity_prep(struct bio *bio)
396{
397 struct bio_integrity_payload *bip;
398 struct blk_integrity *bi;
399 struct request_queue *q;
400 void *buf;
401 unsigned long start, end;
402 unsigned int len, nr_pages;
403 unsigned int bytes, offset, i;
404 unsigned int sectors;
405
406 bi = bdev_get_integrity(bio->bi_bdev);
407 q = bdev_get_queue(bio->bi_bdev);
408 BUG_ON(bi == NULL);
409 BUG_ON(bio_integrity(bio));
410
411 sectors = bio_integrity_hw_sectors(bi, bio_sectors(bio));
412
413 /* Allocate kernel buffer for protection data */
414 len = sectors * blk_integrity_tuple_size(bi);
415 buf = kmalloc(len, GFP_NOIO | __GFP_NOFAIL | q->bounce_gfp);
416 if (unlikely(buf == NULL)) {
417 printk(KERN_ERR "could not allocate integrity buffer\n");
418 return -EIO;
419 }
420
421 end = (((unsigned long) buf) + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
422 start = ((unsigned long) buf) >> PAGE_SHIFT;
423 nr_pages = end - start;
424
425 /* Allocate bio integrity payload and integrity vectors */
426 bip = bio_integrity_alloc(bio, GFP_NOIO, nr_pages);
427 if (unlikely(bip == NULL)) {
428 printk(KERN_ERR "could not allocate data integrity bioset\n");
429 kfree(buf);
430 return -EIO;
431 }
432
433 bip->bip_buf = buf;
434 bip->bip_size = len;
435 bip->bip_sector = bio->bi_sector;
436
437 /* Map it */
438 offset = offset_in_page(buf);
439 for (i = 0 ; i < nr_pages ; i++) {
440 int ret;
441 bytes = PAGE_SIZE - offset;
442
443 if (len <= 0)
444 break;
445
446 if (bytes > len)
447 bytes = len;
448
449 ret = bio_integrity_add_page(bio, virt_to_page(buf),
450 bytes, offset);
451
452 if (ret == 0)
453 return 0;
454
455 if (ret < bytes)
456 break;
457
458 buf += bytes;
459 len -= bytes;
460 offset = 0;
461 }
462
463 /* Install custom I/O completion handler if read verify is enabled */
464 if (bio_data_dir(bio) == READ) {
465 bip->bip_end_io = bio->bi_end_io;
466 bio->bi_end_io = bio_integrity_endio;
467 }
468
469 /* Auto-generate integrity metadata if this is a write */
470 if (bio_data_dir(bio) == WRITE)
471 bio_integrity_generate(bio);
472
473 return 0;
474}
475EXPORT_SYMBOL(bio_integrity_prep);
476
477/**
478 * bio_integrity_verify - Verify integrity metadata for a bio
479 * @bio: bio to verify
480 *
481 * Description: This function is called to verify the integrity of a
482 * bio. The data in the bio io_vec is compared to the integrity
483 * metadata returned by the HBA.
484 */
485static int bio_integrity_verify(struct bio *bio)
486{
487 struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
488 struct blk_integrity_exchg bix;
489 struct bio_vec *bv;
490 sector_t sector = bio->bi_integrity->bip_sector;
491 unsigned int i, sectors, total, ret;
492 void *prot_buf = bio->bi_integrity->bip_buf;
493
494 ret = total = 0;
495 bix.disk_name = bio->bi_bdev->bd_disk->disk_name;
496 bix.sector_size = bi->sector_size;
497
498 bio_for_each_segment(bv, bio, i) {
499 void *kaddr = kmap_atomic(bv->bv_page, KM_USER0);
500 bix.data_buf = kaddr + bv->bv_offset;
501 bix.data_size = bv->bv_len;
502 bix.prot_buf = prot_buf;
503 bix.sector = sector;
504
505 ret = bi->verify_fn(&bix);
506
507 if (ret) {
508 kunmap_atomic(kaddr, KM_USER0);
Martin K. Petersen7b24fc42009-01-04 02:43:38 -0500509 return ret;
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200510 }
511
512 sectors = bv->bv_len / bi->sector_size;
513 sector += sectors;
514 prot_buf += sectors * bi->tuple_size;
515 total += sectors * bi->tuple_size;
516 BUG_ON(total > bio->bi_integrity->bip_size);
517
518 kunmap_atomic(kaddr, KM_USER0);
519 }
520
521 return ret;
522}
523
524/**
525 * bio_integrity_verify_fn - Integrity I/O completion worker
526 * @work: Work struct stored in bio to be verified
527 *
528 * Description: This workqueue function is called to complete a READ
529 * request. The function verifies the transferred integrity metadata
530 * and then calls the original bio end_io function.
531 */
532static void bio_integrity_verify_fn(struct work_struct *work)
533{
Jens Axboeb9846792008-06-17 19:05:48 +0200534 struct bio_integrity_payload *bip =
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200535 container_of(work, struct bio_integrity_payload, bip_work);
536 struct bio *bio = bip->bip_bio;
Martin K. Petersen7b24fc42009-01-04 02:43:38 -0500537 int error;
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200538
Martin K. Petersen7b24fc42009-01-04 02:43:38 -0500539 error = bio_integrity_verify(bio);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200540
541 /* Restore original bio completion handler */
542 bio->bi_end_io = bip->bip_end_io;
Martin K. Petersen7b24fc42009-01-04 02:43:38 -0500543 bio_endio(bio, error);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200544}
545
546/**
547 * bio_integrity_endio - Integrity I/O completion function
548 * @bio: Protected bio
549 * @error: Pointer to errno
550 *
551 * Description: Completion for integrity I/O
552 *
553 * Normally I/O completion is done in interrupt context. However,
554 * verifying I/O integrity is a time-consuming task which must be run
555 * in process context. This function postpones completion
556 * accordingly.
557 */
558void bio_integrity_endio(struct bio *bio, int error)
559{
560 struct bio_integrity_payload *bip = bio->bi_integrity;
561
562 BUG_ON(bip->bip_bio != bio);
563
Martin K. Petersen7b24fc42009-01-04 02:43:38 -0500564 /* In case of an I/O error there is no point in verifying the
565 * integrity metadata. Restore original bio end_io handler
566 * and run it.
567 */
568 if (error) {
569 bio->bi_end_io = bip->bip_end_io;
570 bio_endio(bio, error);
571
572 return;
573 }
574
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200575 INIT_WORK(&bip->bip_work, bio_integrity_verify_fn);
576 queue_work(kintegrityd_wq, &bip->bip_work);
577}
578EXPORT_SYMBOL(bio_integrity_endio);
579
580/**
581 * bio_integrity_mark_head - Advance bip_vec skip bytes
582 * @bip: Integrity vector to advance
583 * @skip: Number of bytes to advance it
584 */
Jens Axboeb9846792008-06-17 19:05:48 +0200585void bio_integrity_mark_head(struct bio_integrity_payload *bip,
586 unsigned int skip)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200587{
588 struct bio_vec *iv;
589 unsigned int i;
590
591 bip_for_each_vec(iv, bip, i) {
592 if (skip == 0) {
593 bip->bip_idx = i;
594 return;
595 } else if (skip >= iv->bv_len) {
596 skip -= iv->bv_len;
597 } else { /* skip < iv->bv_len) */
598 iv->bv_offset += skip;
599 iv->bv_len -= skip;
600 bip->bip_idx = i;
601 return;
602 }
603 }
604}
605
606/**
607 * bio_integrity_mark_tail - Truncate bip_vec to be len bytes long
608 * @bip: Integrity vector to truncate
609 * @len: New length of integrity vector
610 */
Jens Axboeb9846792008-06-17 19:05:48 +0200611void bio_integrity_mark_tail(struct bio_integrity_payload *bip,
612 unsigned int len)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200613{
614 struct bio_vec *iv;
615 unsigned int i;
616
617 bip_for_each_vec(iv, bip, i) {
618 if (len == 0) {
619 bip->bip_vcnt = i;
620 return;
621 } else if (len >= iv->bv_len) {
622 len -= iv->bv_len;
623 } else { /* len < iv->bv_len) */
624 iv->bv_len = len;
625 len = 0;
626 }
627 }
628}
629
630/**
631 * bio_integrity_advance - Advance integrity vector
632 * @bio: bio whose integrity vector to update
633 * @bytes_done: number of data bytes that have been completed
634 *
635 * Description: This function calculates how many integrity bytes the
636 * number of completed data bytes correspond to and advances the
637 * integrity vector accordingly.
638 */
639void bio_integrity_advance(struct bio *bio, unsigned int bytes_done)
640{
641 struct bio_integrity_payload *bip = bio->bi_integrity;
642 struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
643 unsigned int nr_sectors;
644
645 BUG_ON(bip == NULL);
646 BUG_ON(bi == NULL);
647
648 nr_sectors = bio_integrity_hw_sectors(bi, bytes_done >> 9);
649 bio_integrity_mark_head(bip, nr_sectors * bi->tuple_size);
650}
651EXPORT_SYMBOL(bio_integrity_advance);
652
653/**
654 * bio_integrity_trim - Trim integrity vector
655 * @bio: bio whose integrity vector to update
656 * @offset: offset to first data sector
657 * @sectors: number of data sectors
658 *
659 * Description: Used to trim the integrity vector in a cloned bio.
660 * The ivec will be advanced corresponding to 'offset' data sectors
661 * and the length will be truncated corresponding to 'len' data
662 * sectors.
663 */
Jens Axboeb9846792008-06-17 19:05:48 +0200664void bio_integrity_trim(struct bio *bio, unsigned int offset,
665 unsigned int sectors)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200666{
667 struct bio_integrity_payload *bip = bio->bi_integrity;
668 struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
669 unsigned int nr_sectors;
670
671 BUG_ON(bip == NULL);
672 BUG_ON(bi == NULL);
673 BUG_ON(!bio_flagged(bio, BIO_CLONED));
674
675 nr_sectors = bio_integrity_hw_sectors(bi, sectors);
676 bip->bip_sector = bip->bip_sector + offset;
677 bio_integrity_mark_head(bip, offset * bi->tuple_size);
678 bio_integrity_mark_tail(bip, sectors * bi->tuple_size);
679}
680EXPORT_SYMBOL(bio_integrity_trim);
681
682/**
683 * bio_integrity_split - Split integrity metadata
684 * @bio: Protected bio
685 * @bp: Resulting bio_pair
686 * @sectors: Offset
687 *
688 * Description: Splits an integrity page into a bio_pair.
689 */
690void bio_integrity_split(struct bio *bio, struct bio_pair *bp, int sectors)
691{
692 struct blk_integrity *bi;
693 struct bio_integrity_payload *bip = bio->bi_integrity;
694 unsigned int nr_sectors;
695
696 if (bio_integrity(bio) == 0)
697 return;
698
699 bi = bdev_get_integrity(bio->bi_bdev);
700 BUG_ON(bi == NULL);
701 BUG_ON(bip->bip_vcnt != 1);
702
703 nr_sectors = bio_integrity_hw_sectors(bi, sectors);
704
705 bp->bio1.bi_integrity = &bp->bip1;
706 bp->bio2.bi_integrity = &bp->bip2;
707
708 bp->iv1 = bip->bip_vec[0];
709 bp->iv2 = bip->bip_vec[0];
710
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200711 bp->bip1.bip_vec[0] = bp->iv1;
712 bp->bip2.bip_vec[0] = bp->iv2;
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200713
714 bp->iv1.bv_len = sectors * bi->tuple_size;
715 bp->iv2.bv_offset += sectors * bi->tuple_size;
716 bp->iv2.bv_len -= sectors * bi->tuple_size;
717
718 bp->bip1.bip_sector = bio->bi_integrity->bip_sector;
719 bp->bip2.bip_sector = bio->bi_integrity->bip_sector + nr_sectors;
720
721 bp->bip1.bip_vcnt = bp->bip2.bip_vcnt = 1;
722 bp->bip1.bip_idx = bp->bip2.bip_idx = 0;
723}
724EXPORT_SYMBOL(bio_integrity_split);
725
726/**
727 * bio_integrity_clone - Callback for cloning bios with integrity metadata
728 * @bio: New bio
729 * @bio_src: Original bio
un'ichi Nomura87092692009-03-09 10:40:52 +0100730 * @gfp_mask: Memory allocation mask
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200731 * @bs: bio_set to allocate bip from
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200732 *
733 * Description: Called to allocate a bip when cloning a bio
734 */
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200735int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
736 gfp_t gfp_mask, struct bio_set *bs)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200737{
738 struct bio_integrity_payload *bip_src = bio_src->bi_integrity;
739 struct bio_integrity_payload *bip;
740
741 BUG_ON(bip_src == NULL);
742
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200743 bip = bio_integrity_alloc_bioset(bio, gfp_mask, bip_src->bip_vcnt, bs);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200744
745 if (bip == NULL)
746 return -EIO;
747
748 memcpy(bip->bip_vec, bip_src->bip_vec,
749 bip_src->bip_vcnt * sizeof(struct bio_vec));
750
751 bip->bip_sector = bip_src->bip_sector;
752 bip->bip_vcnt = bip_src->bip_vcnt;
753 bip->bip_idx = bip_src->bip_idx;
754
755 return 0;
756}
757EXPORT_SYMBOL(bio_integrity_clone);
758
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200759int bioset_integrity_create(struct bio_set *bs, int pool_size)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200760{
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200761 unsigned int max_slab = vecs_to_idx(BIO_MAX_PAGES);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200762
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200763 bs->bio_integrity_pool =
764 mempool_create_slab_pool(pool_size, bip_slab[max_slab].slab);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200765
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200766 if (!bs->bio_integrity_pool)
767 return -1;
Martin K. Petersen6d2a78e2009-03-10 08:27:39 +0100768
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200769 return 0;
770}
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200771EXPORT_SYMBOL(bioset_integrity_create);
772
773void bioset_integrity_free(struct bio_set *bs)
774{
775 if (bs->bio_integrity_pool)
776 mempool_destroy(bs->bio_integrity_pool);
777}
778EXPORT_SYMBOL(bioset_integrity_free);
779
780void __init bio_integrity_init(void)
781{
782 unsigned int i;
783
784 kintegrityd_wq = create_workqueue("kintegrityd");
785 if (!kintegrityd_wq)
786 panic("Failed to create kintegrityd\n");
787
788 for (i = 0 ; i < BIOVEC_NR_POOLS ; i++) {
789 unsigned int size;
790
791 size = sizeof(struct bio_integrity_payload)
792 + bip_slab[i].nr_vecs * sizeof(struct bio_vec);
793
794 bip_slab[i].slab =
795 kmem_cache_create(bip_slab[i].name, size, 0,
796 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
797 }
798}