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

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