Root/fs/bio-integrity.c

1/*
2 * bio-integrity.c - bio data integrity extensions
3 *
4 * Copyright (C) 2007, 2008, 2009 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#include <linux/slab.h>
28
29struct integrity_slab {
30    struct kmem_cache *slab;
31    unsigned short nr_vecs;
32    char name[8];
33};
34
35#define IS(x) { .nr_vecs = x, .name = "bip-"__stringify(x) }
36struct integrity_slab bip_slab[BIOVEC_NR_POOLS] __read_mostly = {
37    IS(1), IS(4), IS(16), IS(64), IS(128), IS(BIO_MAX_PAGES),
38};
39#undef IS
40
41static struct workqueue_struct *kintegrityd_wq;
42
43static inline unsigned int vecs_to_idx(unsigned int nr)
44{
45    switch (nr) {
46    case 1:
47        return 0;
48    case 2 ... 4:
49        return 1;
50    case 5 ... 16:
51        return 2;
52    case 17 ... 64:
53        return 3;
54    case 65 ... 128:
55        return 4;
56    case 129 ... BIO_MAX_PAGES:
57        return 5;
58    default:
59        BUG();
60    }
61}
62
63static inline int use_bip_pool(unsigned int idx)
64{
65    if (idx == BIOVEC_MAX_IDX)
66        return 1;
67
68    return 0;
69}
70
71/**
72 * bio_integrity_alloc_bioset - Allocate integrity payload and attach it to bio
73 * @bio: bio to attach integrity metadata to
74 * @gfp_mask: Memory allocation mask
75 * @nr_vecs: Number of integrity metadata scatter-gather elements
76 * @bs: bio_set to allocate from
77 *
78 * Description: This function prepares a bio for attaching integrity
79 * metadata. nr_vecs specifies the maximum number of pages containing
80 * integrity metadata that can be attached.
81 */
82struct bio_integrity_payload *bio_integrity_alloc_bioset(struct bio *bio,
83                             gfp_t gfp_mask,
84                             unsigned int nr_vecs,
85                             struct bio_set *bs)
86{
87    struct bio_integrity_payload *bip;
88    unsigned int idx = vecs_to_idx(nr_vecs);
89
90    BUG_ON(bio == NULL);
91    bip = NULL;
92
93    /* Lower order allocations come straight from slab */
94    if (!use_bip_pool(idx))
95        bip = kmem_cache_alloc(bip_slab[idx].slab, gfp_mask);
96
97    /* Use mempool if lower order alloc failed or max vecs were requested */
98    if (bip == NULL) {
99        idx = BIOVEC_MAX_IDX; /* so we free the payload properly later */
100        bip = mempool_alloc(bs->bio_integrity_pool, gfp_mask);
101
102        if (unlikely(bip == NULL)) {
103            printk(KERN_ERR "%s: could not alloc bip\n", __func__);
104            return NULL;
105        }
106    }
107
108    memset(bip, 0, sizeof(*bip));
109
110    bip->bip_slab = idx;
111    bip->bip_bio = bio;
112    bio->bi_integrity = bip;
113
114    return bip;
115}
116EXPORT_SYMBOL(bio_integrity_alloc_bioset);
117
118/**
119 * bio_integrity_alloc - Allocate integrity payload and attach it to bio
120 * @bio: bio to attach integrity metadata to
121 * @gfp_mask: Memory allocation mask
122 * @nr_vecs: Number of integrity metadata scatter-gather elements
123 *
124 * Description: This function prepares a bio for attaching integrity
125 * metadata. nr_vecs specifies the maximum number of pages containing
126 * integrity metadata that can be attached.
127 */
128struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
129                          gfp_t gfp_mask,
130                          unsigned int nr_vecs)
131{
132    return bio_integrity_alloc_bioset(bio, gfp_mask, nr_vecs, fs_bio_set);
133}
134EXPORT_SYMBOL(bio_integrity_alloc);
135
136/**
137 * bio_integrity_free - Free bio integrity payload
138 * @bio: bio containing bip to be freed
139 * @bs: bio_set this bio was allocated from
140 *
141 * Description: Used to free the integrity portion of a bio. Usually
142 * called from bio_free().
143 */
144void bio_integrity_free(struct bio *bio, struct bio_set *bs)
145{
146    struct bio_integrity_payload *bip = bio->bi_integrity;
147
148    BUG_ON(bip == NULL);
149
150    /* A cloned bio doesn't own the integrity metadata */
151    if (!bio_flagged(bio, BIO_CLONED) && !bio_flagged(bio, BIO_FS_INTEGRITY)
152        && bip->bip_buf != NULL)
153        kfree(bip->bip_buf);
154
155    if (use_bip_pool(bip->bip_slab))
156        mempool_free(bip, bs->bio_integrity_pool);
157    else
158        kmem_cache_free(bip_slab[bip->bip_slab].slab, bip);
159
160    bio->bi_integrity = NULL;
161}
162EXPORT_SYMBOL(bio_integrity_free);
163
164/**
165 * bio_integrity_add_page - Attach integrity metadata
166 * @bio: bio to update
167 * @page: page containing integrity metadata
168 * @len: number of bytes of integrity metadata in page
169 * @offset: start offset within page
170 *
171 * Description: Attach a page containing integrity metadata to bio.
172 */
173int bio_integrity_add_page(struct bio *bio, struct page *page,
174               unsigned int len, unsigned int offset)
175{
176    struct bio_integrity_payload *bip = bio->bi_integrity;
177    struct bio_vec *iv;
178
179    if (bip->bip_vcnt >= bvec_nr_vecs(bip->bip_slab)) {
180        printk(KERN_ERR "%s: bip_vec full\n", __func__);
181        return 0;
182    }
183
184    iv = bip_vec_idx(bip, bip->bip_vcnt);
185    BUG_ON(iv == NULL);
186
187    iv->bv_page = page;
188    iv->bv_len = len;
189    iv->bv_offset = offset;
190    bip->bip_vcnt++;
191
192    return len;
193}
194EXPORT_SYMBOL(bio_integrity_add_page);
195
196static int bdev_integrity_enabled(struct block_device *bdev, int rw)
197{
198    struct blk_integrity *bi = bdev_get_integrity(bdev);
199
200    if (bi == NULL)
201        return 0;
202
203    if (rw == READ && bi->verify_fn != NULL &&
204        (bi->flags & INTEGRITY_FLAG_READ))
205        return 1;
206
207    if (rw == WRITE && bi->generate_fn != NULL &&
208        (bi->flags & INTEGRITY_FLAG_WRITE))
209        return 1;
210
211    return 0;
212}
213
214/**
215 * bio_integrity_enabled - Check whether integrity can be passed
216 * @bio: bio to check
217 *
218 * Description: Determines whether bio_integrity_prep() can be called
219 * on this bio or not. bio data direction and target device must be
220 * set prior to calling. The functions honors the write_generate and
221 * read_verify flags in sysfs.
222 */
223int bio_integrity_enabled(struct bio *bio)
224{
225    /* Already protected? */
226    if (bio_integrity(bio))
227        return 0;
228
229    return bdev_integrity_enabled(bio->bi_bdev, bio_data_dir(bio));
230}
231EXPORT_SYMBOL(bio_integrity_enabled);
232
233/**
234 * bio_integrity_hw_sectors - Convert 512b sectors to hardware ditto
235 * @bi: blk_integrity profile for device
236 * @sectors: Number of 512 sectors to convert
237 *
238 * Description: The block layer calculates everything in 512 byte
239 * sectors but integrity metadata is done in terms of the hardware
240 * sector size of the storage device. Convert the block layer sectors
241 * to physical sectors.
242 */
243static inline unsigned int bio_integrity_hw_sectors(struct blk_integrity *bi,
244                            unsigned int sectors)
245{
246    /* At this point there are only 512b or 4096b DIF/EPP devices */
247    if (bi->sector_size == 4096)
248        return sectors >>= 3;
249
250    return sectors;
251}
252
253/**
254 * bio_integrity_tag_size - Retrieve integrity tag space
255 * @bio: bio to inspect
256 *
257 * Description: Returns the maximum number of tag bytes that can be
258 * attached to this bio. Filesystems can use this to determine how
259 * much metadata to attach to an I/O.
260 */
261unsigned int bio_integrity_tag_size(struct bio *bio)
262{
263    struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
264
265    BUG_ON(bio->bi_size == 0);
266
267    return bi->tag_size * (bio->bi_size / bi->sector_size);
268}
269EXPORT_SYMBOL(bio_integrity_tag_size);
270
271int bio_integrity_tag(struct bio *bio, void *tag_buf, unsigned int len, int set)
272{
273    struct bio_integrity_payload *bip = bio->bi_integrity;
274    struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
275    unsigned int nr_sectors;
276
277    BUG_ON(bip->bip_buf == NULL);
278
279    if (bi->tag_size == 0)
280        return -1;
281
282    nr_sectors = bio_integrity_hw_sectors(bi,
283                    DIV_ROUND_UP(len, bi->tag_size));
284
285    if (nr_sectors * bi->tuple_size > bip->bip_size) {
286        printk(KERN_ERR "%s: tag too big for bio: %u > %u\n",
287               __func__, nr_sectors * bi->tuple_size, bip->bip_size);
288        return -1;
289    }
290
291    if (set)
292        bi->set_tag_fn(bip->bip_buf, tag_buf, nr_sectors);
293    else
294        bi->get_tag_fn(bip->bip_buf, tag_buf, nr_sectors);
295
296    return 0;
297}
298
299/**
300 * bio_integrity_set_tag - Attach a tag buffer to a bio
301 * @bio: bio to attach buffer to
302 * @tag_buf: Pointer to a buffer containing tag data
303 * @len: Length of the included buffer
304 *
305 * Description: Use this function to tag a bio by leveraging the extra
306 * space provided by devices formatted with integrity protection. The
307 * size of the integrity buffer must be <= to the size reported by
308 * bio_integrity_tag_size().
309 */
310int bio_integrity_set_tag(struct bio *bio, void *tag_buf, unsigned int len)
311{
312    BUG_ON(bio_data_dir(bio) != WRITE);
313
314    return bio_integrity_tag(bio, tag_buf, len, 1);
315}
316EXPORT_SYMBOL(bio_integrity_set_tag);
317
318/**
319 * bio_integrity_get_tag - Retrieve a tag buffer from a bio
320 * @bio: bio to retrieve buffer from
321 * @tag_buf: Pointer to a buffer for the tag data
322 * @len: Length of the target buffer
323 *
324 * Description: Use this function to retrieve the tag buffer from a
325 * completed I/O. The size of the integrity buffer must be <= to the
326 * size reported by bio_integrity_tag_size().
327 */
328int bio_integrity_get_tag(struct bio *bio, void *tag_buf, unsigned int len)
329{
330    BUG_ON(bio_data_dir(bio) != READ);
331
332    return bio_integrity_tag(bio, tag_buf, len, 0);
333}
334EXPORT_SYMBOL(bio_integrity_get_tag);
335
336/**
337 * bio_integrity_generate - Generate integrity metadata for a bio
338 * @bio: bio to generate integrity metadata for
339 *
340 * Description: Generates integrity metadata for a bio by calling the
341 * block device's generation callback function. The bio must have a
342 * bip attached with enough room to accommodate the generated
343 * integrity metadata.
344 */
345static void bio_integrity_generate(struct bio *bio)
346{
347    struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
348    struct blk_integrity_exchg bix;
349    struct bio_vec *bv;
350    sector_t sector = bio->bi_sector;
351    unsigned int i, sectors, total;
352    void *prot_buf = bio->bi_integrity->bip_buf;
353
354    total = 0;
355    bix.disk_name = bio->bi_bdev->bd_disk->disk_name;
356    bix.sector_size = bi->sector_size;
357
358    bio_for_each_segment(bv, bio, i) {
359        void *kaddr = kmap_atomic(bv->bv_page, KM_USER0);
360        bix.data_buf = kaddr + bv->bv_offset;
361        bix.data_size = bv->bv_len;
362        bix.prot_buf = prot_buf;
363        bix.sector = sector;
364
365        bi->generate_fn(&bix);
366
367        sectors = bv->bv_len / bi->sector_size;
368        sector += sectors;
369        prot_buf += sectors * bi->tuple_size;
370        total += sectors * bi->tuple_size;
371        BUG_ON(total > bio->bi_integrity->bip_size);
372
373        kunmap_atomic(kaddr, KM_USER0);
374    }
375}
376
377static inline unsigned short blk_integrity_tuple_size(struct blk_integrity *bi)
378{
379    if (bi)
380        return bi->tuple_size;
381
382    return 0;
383}
384
385/**
386 * bio_integrity_prep - Prepare bio for integrity I/O
387 * @bio: bio to prepare
388 *
389 * Description: Allocates a buffer for integrity metadata, maps the
390 * pages and attaches them to a bio. The bio must have data
391 * direction, target device and start sector set priot to calling. In
392 * the WRITE case, integrity metadata will be generated using the
393 * block device's integrity function. In the READ case, the buffer
394 * will be prepared for DMA and a suitable end_io handler set up.
395 */
396int bio_integrity_prep(struct bio *bio)
397{
398    struct bio_integrity_payload *bip;
399    struct blk_integrity *bi;
400    struct request_queue *q;
401    void *buf;
402    unsigned long start, end;
403    unsigned int len, nr_pages;
404    unsigned int bytes, offset, i;
405    unsigned int sectors;
406
407    bi = bdev_get_integrity(bio->bi_bdev);
408    q = bdev_get_queue(bio->bi_bdev);
409    BUG_ON(bi == NULL);
410    BUG_ON(bio_integrity(bio));
411
412    sectors = bio_integrity_hw_sectors(bi, bio_sectors(bio));
413
414    /* Allocate kernel buffer for protection data */
415    len = sectors * blk_integrity_tuple_size(bi);
416    buf = kmalloc(len, GFP_NOIO | __GFP_NOFAIL | q->bounce_gfp);
417    if (unlikely(buf == NULL)) {
418        printk(KERN_ERR "could not allocate integrity buffer\n");
419        return -EIO;
420    }
421
422    end = (((unsigned long) buf) + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
423    start = ((unsigned long) buf) >> PAGE_SHIFT;
424    nr_pages = end - start;
425
426    /* Allocate bio integrity payload and integrity vectors */
427    bip = bio_integrity_alloc(bio, GFP_NOIO, nr_pages);
428    if (unlikely(bip == NULL)) {
429        printk(KERN_ERR "could not allocate data integrity bioset\n");
430        kfree(buf);
431        return -EIO;
432    }
433
434    bip->bip_buf = buf;
435    bip->bip_size = len;
436    bip->bip_sector = bio->bi_sector;
437
438    /* Map it */
439    offset = offset_in_page(buf);
440    for (i = 0 ; i < nr_pages ; i++) {
441        int ret;
442        bytes = PAGE_SIZE - offset;
443
444        if (len <= 0)
445            break;
446
447        if (bytes > len)
448            bytes = len;
449
450        ret = bio_integrity_add_page(bio, virt_to_page(buf),
451                         bytes, offset);
452
453        if (ret == 0)
454            return 0;
455
456        if (ret < bytes)
457            break;
458
459        buf += bytes;
460        len -= bytes;
461        offset = 0;
462    }
463
464    /* Install custom I/O completion handler if read verify is enabled */
465    if (bio_data_dir(bio) == READ) {
466        bip->bip_end_io = bio->bi_end_io;
467        bio->bi_end_io = bio_integrity_endio;
468    }
469
470    /* Auto-generate integrity metadata if this is a write */
471    if (bio_data_dir(bio) == WRITE)
472        bio_integrity_generate(bio);
473
474    return 0;
475}
476EXPORT_SYMBOL(bio_integrity_prep);
477
478/**
479 * bio_integrity_verify - Verify integrity metadata for a bio
480 * @bio: bio to verify
481 *
482 * Description: This function is called to verify the integrity of a
483 * bio. The data in the bio io_vec is compared to the integrity
484 * metadata returned by the HBA.
485 */
486static int bio_integrity_verify(struct bio *bio)
487{
488    struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
489    struct blk_integrity_exchg bix;
490    struct bio_vec *bv;
491    sector_t sector = bio->bi_integrity->bip_sector;
492    unsigned int i, sectors, total, ret;
493    void *prot_buf = bio->bi_integrity->bip_buf;
494
495    ret = total = 0;
496    bix.disk_name = bio->bi_bdev->bd_disk->disk_name;
497    bix.sector_size = bi->sector_size;
498
499    bio_for_each_segment(bv, bio, i) {
500        void *kaddr = kmap_atomic(bv->bv_page, KM_USER0);
501        bix.data_buf = kaddr + bv->bv_offset;
502        bix.data_size = bv->bv_len;
503        bix.prot_buf = prot_buf;
504        bix.sector = sector;
505
506        ret = bi->verify_fn(&bix);
507
508        if (ret) {
509            kunmap_atomic(kaddr, KM_USER0);
510            return ret;
511        }
512
513        sectors = bv->bv_len / bi->sector_size;
514        sector += sectors;
515        prot_buf += sectors * bi->tuple_size;
516        total += sectors * bi->tuple_size;
517        BUG_ON(total > bio->bi_integrity->bip_size);
518
519        kunmap_atomic(kaddr, KM_USER0);
520    }
521
522    return ret;
523}
524
525/**
526 * bio_integrity_verify_fn - Integrity I/O completion worker
527 * @work: Work struct stored in bio to be verified
528 *
529 * Description: This workqueue function is called to complete a READ
530 * request. The function verifies the transferred integrity metadata
531 * and then calls the original bio end_io function.
532 */
533static void bio_integrity_verify_fn(struct work_struct *work)
534{
535    struct bio_integrity_payload *bip =
536        container_of(work, struct bio_integrity_payload, bip_work);
537    struct bio *bio = bip->bip_bio;
538    int error;
539
540    error = bio_integrity_verify(bio);
541
542    /* Restore original bio completion handler */
543    bio->bi_end_io = bip->bip_end_io;
544    bio_endio(bio, error);
545}
546
547/**
548 * bio_integrity_endio - Integrity I/O completion function
549 * @bio: Protected bio
550 * @error: Pointer to errno
551 *
552 * Description: Completion for integrity I/O
553 *
554 * Normally I/O completion is done in interrupt context. However,
555 * verifying I/O integrity is a time-consuming task which must be run
556 * in process context. This function postpones completion
557 * accordingly.
558 */
559void bio_integrity_endio(struct bio *bio, int error)
560{
561    struct bio_integrity_payload *bip = bio->bi_integrity;
562
563    BUG_ON(bip->bip_bio != bio);
564
565    /* In case of an I/O error there is no point in verifying the
566     * integrity metadata. Restore original bio end_io handler
567     * and run it.
568     */
569    if (error) {
570        bio->bi_end_io = bip->bip_end_io;
571        bio_endio(bio, error);
572
573        return;
574    }
575
576    INIT_WORK(&bip->bip_work, bio_integrity_verify_fn);
577    queue_work(kintegrityd_wq, &bip->bip_work);
578}
579EXPORT_SYMBOL(bio_integrity_endio);
580
581/**
582 * bio_integrity_mark_head - Advance bip_vec skip bytes
583 * @bip: Integrity vector to advance
584 * @skip: Number of bytes to advance it
585 */
586void bio_integrity_mark_head(struct bio_integrity_payload *bip,
587                 unsigned int skip)
588{
589    struct bio_vec *iv;
590    unsigned int i;
591
592    bip_for_each_vec(iv, bip, i) {
593        if (skip == 0) {
594            bip->bip_idx = i;
595            return;
596        } else if (skip >= iv->bv_len) {
597            skip -= iv->bv_len;
598        } else { /* skip < iv->bv_len) */
599            iv->bv_offset += skip;
600            iv->bv_len -= skip;
601            bip->bip_idx = i;
602            return;
603        }
604    }
605}
606
607/**
608 * bio_integrity_mark_tail - Truncate bip_vec to be len bytes long
609 * @bip: Integrity vector to truncate
610 * @len: New length of integrity vector
611 */
612void bio_integrity_mark_tail(struct bio_integrity_payload *bip,
613                 unsigned int len)
614{
615    struct bio_vec *iv;
616    unsigned int i;
617
618    bip_for_each_vec(iv, bip, i) {
619        if (len == 0) {
620            bip->bip_vcnt = i;
621            return;
622        } else if (len >= iv->bv_len) {
623            len -= iv->bv_len;
624        } else { /* len < iv->bv_len) */
625            iv->bv_len = len;
626            len = 0;
627        }
628    }
629}
630
631/**
632 * bio_integrity_advance - Advance integrity vector
633 * @bio: bio whose integrity vector to update
634 * @bytes_done: number of data bytes that have been completed
635 *
636 * Description: This function calculates how many integrity bytes the
637 * number of completed data bytes correspond to and advances the
638 * integrity vector accordingly.
639 */
640void bio_integrity_advance(struct bio *bio, unsigned int bytes_done)
641{
642    struct bio_integrity_payload *bip = bio->bi_integrity;
643    struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
644    unsigned int nr_sectors;
645
646    BUG_ON(bip == NULL);
647    BUG_ON(bi == NULL);
648
649    nr_sectors = bio_integrity_hw_sectors(bi, bytes_done >> 9);
650    bio_integrity_mark_head(bip, nr_sectors * bi->tuple_size);
651}
652EXPORT_SYMBOL(bio_integrity_advance);
653
654/**
655 * bio_integrity_trim - Trim integrity vector
656 * @bio: bio whose integrity vector to update
657 * @offset: offset to first data sector
658 * @sectors: number of data sectors
659 *
660 * Description: Used to trim the integrity vector in a cloned bio.
661 * The ivec will be advanced corresponding to 'offset' data sectors
662 * and the length will be truncated corresponding to 'len' data
663 * sectors.
664 */
665void bio_integrity_trim(struct bio *bio, unsigned int offset,
666            unsigned int sectors)
667{
668    struct bio_integrity_payload *bip = bio->bi_integrity;
669    struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
670    unsigned int nr_sectors;
671
672    BUG_ON(bip == NULL);
673    BUG_ON(bi == NULL);
674    BUG_ON(!bio_flagged(bio, BIO_CLONED));
675
676    nr_sectors = bio_integrity_hw_sectors(bi, sectors);
677    bip->bip_sector = bip->bip_sector + offset;
678    bio_integrity_mark_head(bip, offset * bi->tuple_size);
679    bio_integrity_mark_tail(bip, sectors * bi->tuple_size);
680}
681EXPORT_SYMBOL(bio_integrity_trim);
682
683/**
684 * bio_integrity_split - Split integrity metadata
685 * @bio: Protected bio
686 * @bp: Resulting bio_pair
687 * @sectors: Offset
688 *
689 * Description: Splits an integrity page into a bio_pair.
690 */
691void bio_integrity_split(struct bio *bio, struct bio_pair *bp, int sectors)
692{
693    struct blk_integrity *bi;
694    struct bio_integrity_payload *bip = bio->bi_integrity;
695    unsigned int nr_sectors;
696
697    if (bio_integrity(bio) == 0)
698        return;
699
700    bi = bdev_get_integrity(bio->bi_bdev);
701    BUG_ON(bi == NULL);
702    BUG_ON(bip->bip_vcnt != 1);
703
704    nr_sectors = bio_integrity_hw_sectors(bi, sectors);
705
706    bp->bio1.bi_integrity = &bp->bip1;
707    bp->bio2.bi_integrity = &bp->bip2;
708
709    bp->iv1 = bip->bip_vec[0];
710    bp->iv2 = bip->bip_vec[0];
711
712    bp->bip1.bip_vec[0] = bp->iv1;
713    bp->bip2.bip_vec[0] = bp->iv2;
714
715    bp->iv1.bv_len = sectors * bi->tuple_size;
716    bp->iv2.bv_offset += sectors * bi->tuple_size;
717    bp->iv2.bv_len -= sectors * bi->tuple_size;
718
719    bp->bip1.bip_sector = bio->bi_integrity->bip_sector;
720    bp->bip2.bip_sector = bio->bi_integrity->bip_sector + nr_sectors;
721
722    bp->bip1.bip_vcnt = bp->bip2.bip_vcnt = 1;
723    bp->bip1.bip_idx = bp->bip2.bip_idx = 0;
724}
725EXPORT_SYMBOL(bio_integrity_split);
726
727/**
728 * bio_integrity_clone - Callback for cloning bios with integrity metadata
729 * @bio: New bio
730 * @bio_src: Original bio
731 * @gfp_mask: Memory allocation mask
732 * @bs: bio_set to allocate bip from
733 *
734 * Description: Called to allocate a bip when cloning a bio
735 */
736int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
737            gfp_t gfp_mask, struct bio_set *bs)
738{
739    struct bio_integrity_payload *bip_src = bio_src->bi_integrity;
740    struct bio_integrity_payload *bip;
741
742    BUG_ON(bip_src == NULL);
743
744    bip = bio_integrity_alloc_bioset(bio, gfp_mask, bip_src->bip_vcnt, bs);
745
746    if (bip == NULL)
747        return -EIO;
748
749    memcpy(bip->bip_vec, bip_src->bip_vec,
750           bip_src->bip_vcnt * sizeof(struct bio_vec));
751
752    bip->bip_sector = bip_src->bip_sector;
753    bip->bip_vcnt = bip_src->bip_vcnt;
754    bip->bip_idx = bip_src->bip_idx;
755
756    return 0;
757}
758EXPORT_SYMBOL(bio_integrity_clone);
759
760int bioset_integrity_create(struct bio_set *bs, int pool_size)
761{
762    unsigned int max_slab = vecs_to_idx(BIO_MAX_PAGES);
763
764    bs->bio_integrity_pool =
765        mempool_create_slab_pool(pool_size, bip_slab[max_slab].slab);
766
767    if (!bs->bio_integrity_pool)
768        return -1;
769
770    return 0;
771}
772EXPORT_SYMBOL(bioset_integrity_create);
773
774void bioset_integrity_free(struct bio_set *bs)
775{
776    if (bs->bio_integrity_pool)
777        mempool_destroy(bs->bio_integrity_pool);
778}
779EXPORT_SYMBOL(bioset_integrity_free);
780
781void __init bio_integrity_init(void)
782{
783    unsigned int i;
784
785    kintegrityd_wq = create_workqueue("kintegrityd");
786    if (!kintegrityd_wq)
787        panic("Failed to create kintegrityd\n");
788
789    for (i = 0 ; i < BIOVEC_NR_POOLS ; i++) {
790        unsigned int size;
791
792        size = sizeof(struct bio_integrity_payload)
793            + bip_slab[i].nr_vecs * sizeof(struct bio_vec);
794
795        bip_slab[i].slab =
796            kmem_cache_create(bip_slab[i].name, size, 0,
797                      SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
798    }
799}
800

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