Root/fs/bio-integrity.c

Source at commit 9845c1745d3d531a5b9544f5322c62bfb4d4e9bc created 1 year 2 months ago.
By Xiangfu, rtc: jz4740 fix hwclock give time out
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/export.h>
26#include <linux/bio.h>
27#include <linux/workqueue.h>
28#include <linux/slab.h>
29
30struct integrity_slab {
31    struct kmem_cache *slab;
32    unsigned short nr_vecs;
33    char name[8];
34};
35
36#define IS(x) { .nr_vecs = x, .name = "bip-"__stringify(x) }
37struct integrity_slab bip_slab[BIOVEC_NR_POOLS] __read_mostly = {
38    IS(1), IS(4), IS(16), IS(64), IS(128), IS(BIO_MAX_PAGES),
39};
40#undef IS
41
42static struct workqueue_struct *kintegrityd_wq;
43
44static inline unsigned int vecs_to_idx(unsigned int nr)
45{
46    switch (nr) {
47    case 1:
48        return 0;
49    case 2 ... 4:
50        return 1;
51    case 5 ... 16:
52        return 2;
53    case 17 ... 64:
54        return 3;
55    case 65 ... 128:
56        return 4;
57    case 129 ... BIO_MAX_PAGES:
58        return 5;
59    default:
60        BUG();
61    }
62}
63
64static inline int use_bip_pool(unsigned int idx)
65{
66    if (idx == BIOVEC_MAX_IDX)
67        return 1;
68
69    return 0;
70}
71
72/**
73 * bio_integrity_alloc_bioset - Allocate integrity payload and attach it to bio
74 * @bio: bio to attach integrity metadata to
75 * @gfp_mask: Memory allocation mask
76 * @nr_vecs: Number of integrity metadata scatter-gather elements
77 * @bs: bio_set to allocate from
78 *
79 * Description: This function prepares a bio for attaching integrity
80 * metadata. nr_vecs specifies the maximum number of pages containing
81 * integrity metadata that can be attached.
82 */
83struct bio_integrity_payload *bio_integrity_alloc_bioset(struct bio *bio,
84                             gfp_t gfp_mask,
85                             unsigned int nr_vecs,
86                             struct bio_set *bs)
87{
88    struct bio_integrity_payload *bip;
89    unsigned int idx = vecs_to_idx(nr_vecs);
90
91    BUG_ON(bio == NULL);
92    bip = NULL;
93
94    /* Lower order allocations come straight from slab */
95    if (!use_bip_pool(idx))
96        bip = kmem_cache_alloc(bip_slab[idx].slab, gfp_mask);
97
98    /* Use mempool if lower order alloc failed or max vecs were requested */
99    if (bip == NULL) {
100        idx = BIOVEC_MAX_IDX; /* so we free the payload properly later */
101        bip = mempool_alloc(bs->bio_integrity_pool, gfp_mask);
102
103        if (unlikely(bip == NULL)) {
104            printk(KERN_ERR "%s: could not alloc bip\n", __func__);
105            return NULL;
106        }
107    }
108
109    memset(bip, 0, sizeof(*bip));
110
111    bip->bip_slab = idx;
112    bip->bip_bio = bio;
113    bio->bi_integrity = bip;
114
115    return bip;
116}
117EXPORT_SYMBOL(bio_integrity_alloc_bioset);
118
119/**
120 * bio_integrity_alloc - Allocate integrity payload and attach it to bio
121 * @bio: bio to attach integrity metadata to
122 * @gfp_mask: Memory allocation mask
123 * @nr_vecs: Number of integrity metadata scatter-gather elements
124 *
125 * Description: This function prepares a bio for attaching integrity
126 * metadata. nr_vecs specifies the maximum number of pages containing
127 * integrity metadata that can be attached.
128 */
129struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
130                          gfp_t gfp_mask,
131                          unsigned int nr_vecs)
132{
133    return bio_integrity_alloc_bioset(bio, gfp_mask, nr_vecs, fs_bio_set);
134}
135EXPORT_SYMBOL(bio_integrity_alloc);
136
137/**
138 * bio_integrity_free - Free bio integrity payload
139 * @bio: bio containing bip to be freed
140 * @bs: bio_set this bio was allocated from
141 *
142 * Description: Used to free the integrity portion of a bio. Usually
143 * called from bio_free().
144 */
145void bio_integrity_free(struct bio *bio, struct bio_set *bs)
146{
147    struct bio_integrity_payload *bip = bio->bi_integrity;
148
149    BUG_ON(bip == NULL);
150
151    /* A cloned bio doesn't own the integrity metadata */
152    if (!bio_flagged(bio, BIO_CLONED) && !bio_flagged(bio, BIO_FS_INTEGRITY)
153        && bip->bip_buf != NULL)
154        kfree(bip->bip_buf);
155
156    if (use_bip_pool(bip->bip_slab))
157        mempool_free(bip, bs->bio_integrity_pool);
158    else
159        kmem_cache_free(bip_slab[bip->bip_slab].slab, bip);
160
161    bio->bi_integrity = NULL;
162}
163EXPORT_SYMBOL(bio_integrity_free);
164
165/**
166 * bio_integrity_add_page - Attach integrity metadata
167 * @bio: bio to update
168 * @page: page containing integrity metadata
169 * @len: number of bytes of integrity metadata in page
170 * @offset: start offset within page
171 *
172 * Description: Attach a page containing integrity metadata to bio.
173 */
174int bio_integrity_add_page(struct bio *bio, struct page *page,
175               unsigned int len, unsigned int offset)
176{
177    struct bio_integrity_payload *bip = bio->bi_integrity;
178    struct bio_vec *iv;
179
180    if (bip->bip_vcnt >= bvec_nr_vecs(bip->bip_slab)) {
181        printk(KERN_ERR "%s: bip_vec full\n", __func__);
182        return 0;
183    }
184
185    iv = bip_vec_idx(bip, bip->bip_vcnt);
186    BUG_ON(iv == NULL);
187
188    iv->bv_page = page;
189    iv->bv_len = len;
190    iv->bv_offset = offset;
191    bip->bip_vcnt++;
192
193    return len;
194}
195EXPORT_SYMBOL(bio_integrity_add_page);
196
197static int bdev_integrity_enabled(struct block_device *bdev, int rw)
198{
199    struct blk_integrity *bi = bdev_get_integrity(bdev);
200
201    if (bi == NULL)
202        return 0;
203
204    if (rw == READ && bi->verify_fn != NULL &&
205        (bi->flags & INTEGRITY_FLAG_READ))
206        return 1;
207
208    if (rw == WRITE && bi->generate_fn != NULL &&
209        (bi->flags & INTEGRITY_FLAG_WRITE))
210        return 1;
211
212    return 0;
213}
214
215/**
216 * bio_integrity_enabled - Check whether integrity can be passed
217 * @bio: bio to check
218 *
219 * Description: Determines whether bio_integrity_prep() can be called
220 * on this bio or not. bio data direction and target device must be
221 * set prior to calling. The functions honors the write_generate and
222 * read_verify flags in sysfs.
223 */
224int bio_integrity_enabled(struct bio *bio)
225{
226    /* Already protected? */
227    if (bio_integrity(bio))
228        return 0;
229
230    return bdev_integrity_enabled(bio->bi_bdev, bio_data_dir(bio));
231}
232EXPORT_SYMBOL(bio_integrity_enabled);
233
234/**
235 * bio_integrity_hw_sectors - Convert 512b sectors to hardware ditto
236 * @bi: blk_integrity profile for device
237 * @sectors: Number of 512 sectors to convert
238 *
239 * Description: The block layer calculates everything in 512 byte
240 * sectors but integrity metadata is done in terms of the hardware
241 * sector size of the storage device. Convert the block layer sectors
242 * to physical sectors.
243 */
244static inline unsigned int bio_integrity_hw_sectors(struct blk_integrity *bi,
245                            unsigned int sectors)
246{
247    /* At this point there are only 512b or 4096b DIF/EPP devices */
248    if (bi->sector_size == 4096)
249        return sectors >>= 3;
250
251    return sectors;
252}
253
254/**
255 * bio_integrity_tag_size - Retrieve integrity tag space
256 * @bio: bio to inspect
257 *
258 * Description: Returns the maximum number of tag bytes that can be
259 * attached to this bio. Filesystems can use this to determine how
260 * much metadata to attach to an I/O.
261 */
262unsigned int bio_integrity_tag_size(struct bio *bio)
263{
264    struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
265
266    BUG_ON(bio->bi_size == 0);
267
268    return bi->tag_size * (bio->bi_size / bi->sector_size);
269}
270EXPORT_SYMBOL(bio_integrity_tag_size);
271
272int bio_integrity_tag(struct bio *bio, void *tag_buf, unsigned int len, int set)
273{
274    struct bio_integrity_payload *bip = bio->bi_integrity;
275    struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
276    unsigned int nr_sectors;
277
278    BUG_ON(bip->bip_buf == NULL);
279
280    if (bi->tag_size == 0)
281        return -1;
282
283    nr_sectors = bio_integrity_hw_sectors(bi,
284                    DIV_ROUND_UP(len, bi->tag_size));
285
286    if (nr_sectors * bi->tuple_size > bip->bip_size) {
287        printk(KERN_ERR "%s: tag too big for bio: %u > %u\n",
288               __func__, nr_sectors * bi->tuple_size, bip->bip_size);
289        return -1;
290    }
291
292    if (set)
293        bi->set_tag_fn(bip->bip_buf, tag_buf, nr_sectors);
294    else
295        bi->get_tag_fn(bip->bip_buf, tag_buf, nr_sectors);
296
297    return 0;
298}
299
300/**
301 * bio_integrity_set_tag - Attach a tag buffer to a bio
302 * @bio: bio to attach buffer to
303 * @tag_buf: Pointer to a buffer containing tag data
304 * @len: Length of the included buffer
305 *
306 * Description: Use this function to tag a bio by leveraging the extra
307 * space provided by devices formatted with integrity protection. The
308 * size of the integrity buffer must be <= to the size reported by
309 * bio_integrity_tag_size().
310 */
311int bio_integrity_set_tag(struct bio *bio, void *tag_buf, unsigned int len)
312{
313    BUG_ON(bio_data_dir(bio) != WRITE);
314
315    return bio_integrity_tag(bio, tag_buf, len, 1);
316}
317EXPORT_SYMBOL(bio_integrity_set_tag);
318
319/**
320 * bio_integrity_get_tag - Retrieve a tag buffer from a bio
321 * @bio: bio to retrieve buffer from
322 * @tag_buf: Pointer to a buffer for the tag data
323 * @len: Length of the target buffer
324 *
325 * Description: Use this function to retrieve the tag buffer from a
326 * completed I/O. The size of the integrity buffer must be <= to the
327 * size reported by bio_integrity_tag_size().
328 */
329int bio_integrity_get_tag(struct bio *bio, void *tag_buf, unsigned int len)
330{
331    BUG_ON(bio_data_dir(bio) != READ);
332
333    return bio_integrity_tag(bio, tag_buf, len, 0);
334}
335EXPORT_SYMBOL(bio_integrity_get_tag);
336
337/**
338 * bio_integrity_generate - Generate integrity metadata for a bio
339 * @bio: bio to generate integrity metadata for
340 *
341 * Description: Generates integrity metadata for a bio by calling the
342 * block device's generation callback function. The bio must have a
343 * bip attached with enough room to accommodate the generated
344 * integrity metadata.
345 */
346static void bio_integrity_generate(struct bio *bio)
347{
348    struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
349    struct blk_integrity_exchg bix;
350    struct bio_vec *bv;
351    sector_t sector = bio->bi_sector;
352    unsigned int i, sectors, total;
353    void *prot_buf = bio->bi_integrity->bip_buf;
354
355    total = 0;
356    bix.disk_name = bio->bi_bdev->bd_disk->disk_name;
357    bix.sector_size = bi->sector_size;
358
359    bio_for_each_segment(bv, bio, i) {
360        void *kaddr = kmap_atomic(bv->bv_page, KM_USER0);
361        bix.data_buf = kaddr + bv->bv_offset;
362        bix.data_size = bv->bv_len;
363        bix.prot_buf = prot_buf;
364        bix.sector = sector;
365
366        bi->generate_fn(&bix);
367
368        sectors = bv->bv_len / bi->sector_size;
369        sector += sectors;
370        prot_buf += sectors * bi->tuple_size;
371        total += sectors * bi->tuple_size;
372        BUG_ON(total > bio->bi_integrity->bip_size);
373
374        kunmap_atomic(kaddr, KM_USER0);
375    }
376}
377
378static inline unsigned short blk_integrity_tuple_size(struct blk_integrity *bi)
379{
380    if (bi)
381        return bi->tuple_size;
382
383    return 0;
384}
385
386/**
387 * bio_integrity_prep - Prepare bio for integrity I/O
388 * @bio: bio to prepare
389 *
390 * Description: Allocates a buffer for integrity metadata, maps the
391 * pages and attaches them to a bio. The bio must have data
392 * direction, target device and start sector set priot to calling. In
393 * the WRITE case, integrity metadata will be generated using the
394 * block device's integrity function. In the READ case, the buffer
395 * will be prepared for DMA and a suitable end_io handler set up.
396 */
397int bio_integrity_prep(struct bio *bio)
398{
399    struct bio_integrity_payload *bip;
400    struct blk_integrity *bi;
401    struct request_queue *q;
402    void *buf;
403    unsigned long start, end;
404    unsigned int len, nr_pages;
405    unsigned int bytes, offset, i;
406    unsigned int sectors;
407
408    bi = bdev_get_integrity(bio->bi_bdev);
409    q = bdev_get_queue(bio->bi_bdev);
410    BUG_ON(bi == NULL);
411    BUG_ON(bio_integrity(bio));
412
413    sectors = bio_integrity_hw_sectors(bi, bio_sectors(bio));
414
415    /* Allocate kernel buffer for protection data */
416    len = sectors * blk_integrity_tuple_size(bi);
417    buf = kmalloc(len, GFP_NOIO | q->bounce_gfp);
418    if (unlikely(buf == NULL)) {
419        printk(KERN_ERR "could not allocate integrity buffer\n");
420        return -ENOMEM;
421    }
422
423    end = (((unsigned long) buf) + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
424    start = ((unsigned long) buf) >> PAGE_SHIFT;
425    nr_pages = end - start;
426
427    /* Allocate bio integrity payload and integrity vectors */
428    bip = bio_integrity_alloc(bio, GFP_NOIO, nr_pages);
429    if (unlikely(bip == NULL)) {
430        printk(KERN_ERR "could not allocate data integrity bioset\n");
431        kfree(buf);
432        return -EIO;
433    }
434
435    bip->bip_buf = buf;
436    bip->bip_size = len;
437    bip->bip_sector = bio->bi_sector;
438
439    /* Map it */
440    offset = offset_in_page(buf);
441    for (i = 0 ; i < nr_pages ; i++) {
442        int ret;
443        bytes = PAGE_SIZE - offset;
444
445        if (len <= 0)
446            break;
447
448        if (bytes > len)
449            bytes = len;
450
451        ret = bio_integrity_add_page(bio, virt_to_page(buf),
452                         bytes, offset);
453
454        if (ret == 0)
455            return 0;
456
457        if (ret < bytes)
458            break;
459
460        buf += bytes;
461        len -= bytes;
462        offset = 0;
463    }
464
465    /* Install custom I/O completion handler if read verify is enabled */
466    if (bio_data_dir(bio) == READ) {
467        bip->bip_end_io = bio->bi_end_io;
468        bio->bi_end_io = bio_integrity_endio;
469    }
470
471    /* Auto-generate integrity metadata if this is a write */
472    if (bio_data_dir(bio) == WRITE)
473        bio_integrity_generate(bio);
474
475    return 0;
476}
477EXPORT_SYMBOL(bio_integrity_prep);
478
479/**
480 * bio_integrity_verify - Verify integrity metadata for a bio
481 * @bio: bio to verify
482 *
483 * Description: This function is called to verify the integrity of a
484 * bio. The data in the bio io_vec is compared to the integrity
485 * metadata returned by the HBA.
486 */
487static int bio_integrity_verify(struct bio *bio)
488{
489    struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
490    struct blk_integrity_exchg bix;
491    struct bio_vec *bv;
492    sector_t sector = bio->bi_integrity->bip_sector;
493    unsigned int i, sectors, total, ret;
494    void *prot_buf = bio->bi_integrity->bip_buf;
495
496    ret = total = 0;
497    bix.disk_name = bio->bi_bdev->bd_disk->disk_name;
498    bix.sector_size = bi->sector_size;
499
500    bio_for_each_segment(bv, bio, i) {
501        void *kaddr = kmap_atomic(bv->bv_page, KM_USER0);
502        bix.data_buf = kaddr + bv->bv_offset;
503        bix.data_size = bv->bv_len;
504        bix.prot_buf = prot_buf;
505        bix.sector = sector;
506
507        ret = bi->verify_fn(&bix);
508
509        if (ret) {
510            kunmap_atomic(kaddr, KM_USER0);
511            return ret;
512        }
513
514        sectors = bv->bv_len / bi->sector_size;
515        sector += sectors;
516        prot_buf += sectors * bi->tuple_size;
517        total += sectors * bi->tuple_size;
518        BUG_ON(total > bio->bi_integrity->bip_size);
519
520        kunmap_atomic(kaddr, KM_USER0);
521    }
522
523    return ret;
524}
525
526/**
527 * bio_integrity_verify_fn - Integrity I/O completion worker
528 * @work: Work struct stored in bio to be verified
529 *
530 * Description: This workqueue function is called to complete a READ
531 * request. The function verifies the transferred integrity metadata
532 * and then calls the original bio end_io function.
533 */
534static void bio_integrity_verify_fn(struct work_struct *work)
535{
536    struct bio_integrity_payload *bip =
537        container_of(work, struct bio_integrity_payload, bip_work);
538    struct bio *bio = bip->bip_bio;
539    int error;
540
541    error = bio_integrity_verify(bio);
542
543    /* Restore original bio completion handler */
544    bio->bi_end_io = bip->bip_end_io;
545    bio_endio(bio, error);
546}
547
548/**
549 * bio_integrity_endio - Integrity I/O completion function
550 * @bio: Protected bio
551 * @error: Pointer to errno
552 *
553 * Description: Completion for integrity I/O
554 *
555 * Normally I/O completion is done in interrupt context. However,
556 * verifying I/O integrity is a time-consuming task which must be run
557 * in process context. This function postpones completion
558 * accordingly.
559 */
560void bio_integrity_endio(struct bio *bio, int error)
561{
562    struct bio_integrity_payload *bip = bio->bi_integrity;
563
564    BUG_ON(bip->bip_bio != bio);
565
566    /* In case of an I/O error there is no point in verifying the
567     * integrity metadata. Restore original bio end_io handler
568     * and run it.
569     */
570    if (error) {
571        bio->bi_end_io = bip->bip_end_io;
572        bio_endio(bio, error);
573
574        return;
575    }
576
577    INIT_WORK(&bip->bip_work, bio_integrity_verify_fn);
578    queue_work(kintegrityd_wq, &bip->bip_work);
579}
580EXPORT_SYMBOL(bio_integrity_endio);
581
582/**
583 * bio_integrity_mark_head - Advance bip_vec skip bytes
584 * @bip: Integrity vector to advance
585 * @skip: Number of bytes to advance it
586 */
587void bio_integrity_mark_head(struct bio_integrity_payload *bip,
588                 unsigned int skip)
589{
590    struct bio_vec *iv;
591    unsigned int i;
592
593    bip_for_each_vec(iv, bip, i) {
594        if (skip == 0) {
595            bip->bip_idx = i;
596            return;
597        } else if (skip >= iv->bv_len) {
598            skip -= iv->bv_len;
599        } else { /* skip < iv->bv_len) */
600            iv->bv_offset += skip;
601            iv->bv_len -= skip;
602            bip->bip_idx = i;
603            return;
604        }
605    }
606}
607
608/**
609 * bio_integrity_mark_tail - Truncate bip_vec to be len bytes long
610 * @bip: Integrity vector to truncate
611 * @len: New length of integrity vector
612 */
613void bio_integrity_mark_tail(struct bio_integrity_payload *bip,
614                 unsigned int len)
615{
616    struct bio_vec *iv;
617    unsigned int i;
618
619    bip_for_each_vec(iv, bip, i) {
620        if (len == 0) {
621            bip->bip_vcnt = i;
622            return;
623        } else if (len >= iv->bv_len) {
624            len -= iv->bv_len;
625        } else { /* len < iv->bv_len) */
626            iv->bv_len = len;
627            len = 0;
628        }
629    }
630}
631
632/**
633 * bio_integrity_advance - Advance integrity vector
634 * @bio: bio whose integrity vector to update
635 * @bytes_done: number of data bytes that have been completed
636 *
637 * Description: This function calculates how many integrity bytes the
638 * number of completed data bytes correspond to and advances the
639 * integrity vector accordingly.
640 */
641void bio_integrity_advance(struct bio *bio, unsigned int bytes_done)
642{
643    struct bio_integrity_payload *bip = bio->bi_integrity;
644    struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
645    unsigned int nr_sectors;
646
647    BUG_ON(bip == NULL);
648    BUG_ON(bi == NULL);
649
650    nr_sectors = bio_integrity_hw_sectors(bi, bytes_done >> 9);
651    bio_integrity_mark_head(bip, nr_sectors * bi->tuple_size);
652}
653EXPORT_SYMBOL(bio_integrity_advance);
654
655/**
656 * bio_integrity_trim - Trim integrity vector
657 * @bio: bio whose integrity vector to update
658 * @offset: offset to first data sector
659 * @sectors: number of data sectors
660 *
661 * Description: Used to trim the integrity vector in a cloned bio.
662 * The ivec will be advanced corresponding to 'offset' data sectors
663 * and the length will be truncated corresponding to 'len' data
664 * sectors.
665 */
666void bio_integrity_trim(struct bio *bio, unsigned int offset,
667            unsigned int sectors)
668{
669    struct bio_integrity_payload *bip = bio->bi_integrity;
670    struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
671    unsigned int nr_sectors;
672
673    BUG_ON(bip == NULL);
674    BUG_ON(bi == NULL);
675    BUG_ON(!bio_flagged(bio, BIO_CLONED));
676
677    nr_sectors = bio_integrity_hw_sectors(bi, sectors);
678    bip->bip_sector = bip->bip_sector + offset;
679    bio_integrity_mark_head(bip, offset * bi->tuple_size);
680    bio_integrity_mark_tail(bip, sectors * bi->tuple_size);
681}
682EXPORT_SYMBOL(bio_integrity_trim);
683
684/**
685 * bio_integrity_split - Split integrity metadata
686 * @bio: Protected bio
687 * @bp: Resulting bio_pair
688 * @sectors: Offset
689 *
690 * Description: Splits an integrity page into a bio_pair.
691 */
692void bio_integrity_split(struct bio *bio, struct bio_pair *bp, int sectors)
693{
694    struct blk_integrity *bi;
695    struct bio_integrity_payload *bip = bio->bi_integrity;
696    unsigned int nr_sectors;
697
698    if (bio_integrity(bio) == 0)
699        return;
700
701    bi = bdev_get_integrity(bio->bi_bdev);
702    BUG_ON(bi == NULL);
703    BUG_ON(bip->bip_vcnt != 1);
704
705    nr_sectors = bio_integrity_hw_sectors(bi, sectors);
706
707    bp->bio1.bi_integrity = &bp->bip1;
708    bp->bio2.bi_integrity = &bp->bip2;
709
710    bp->iv1 = bip->bip_vec[0];
711    bp->iv2 = bip->bip_vec[0];
712
713    bp->bip1.bip_vec[0] = bp->iv1;
714    bp->bip2.bip_vec[0] = bp->iv2;
715
716    bp->iv1.bv_len = sectors * bi->tuple_size;
717    bp->iv2.bv_offset += sectors * bi->tuple_size;
718    bp->iv2.bv_len -= sectors * bi->tuple_size;
719
720    bp->bip1.bip_sector = bio->bi_integrity->bip_sector;
721    bp->bip2.bip_sector = bio->bi_integrity->bip_sector + nr_sectors;
722
723    bp->bip1.bip_vcnt = bp->bip2.bip_vcnt = 1;
724    bp->bip1.bip_idx = bp->bip2.bip_idx = 0;
725}
726EXPORT_SYMBOL(bio_integrity_split);
727
728/**
729 * bio_integrity_clone - Callback for cloning bios with integrity metadata
730 * @bio: New bio
731 * @bio_src: Original bio
732 * @gfp_mask: Memory allocation mask
733 * @bs: bio_set to allocate bip from
734 *
735 * Description: Called to allocate a bip when cloning a bio
736 */
737int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
738            gfp_t gfp_mask, struct bio_set *bs)
739{
740    struct bio_integrity_payload *bip_src = bio_src->bi_integrity;
741    struct bio_integrity_payload *bip;
742
743    BUG_ON(bip_src == NULL);
744
745    bip = bio_integrity_alloc_bioset(bio, gfp_mask, bip_src->bip_vcnt, bs);
746
747    if (bip == NULL)
748        return -EIO;
749
750    memcpy(bip->bip_vec, bip_src->bip_vec,
751           bip_src->bip_vcnt * sizeof(struct bio_vec));
752
753    bip->bip_sector = bip_src->bip_sector;
754    bip->bip_vcnt = bip_src->bip_vcnt;
755    bip->bip_idx = bip_src->bip_idx;
756
757    return 0;
758}
759EXPORT_SYMBOL(bio_integrity_clone);
760
761int bioset_integrity_create(struct bio_set *bs, int pool_size)
762{
763    unsigned int max_slab = vecs_to_idx(BIO_MAX_PAGES);
764
765    if (bs->bio_integrity_pool)
766        return 0;
767
768    bs->bio_integrity_pool =
769        mempool_create_slab_pool(pool_size, bip_slab[max_slab].slab);
770
771    if (!bs->bio_integrity_pool)
772        return -1;
773
774    return 0;
775}
776EXPORT_SYMBOL(bioset_integrity_create);
777
778void bioset_integrity_free(struct bio_set *bs)
779{
780    if (bs->bio_integrity_pool)
781        mempool_destroy(bs->bio_integrity_pool);
782}
783EXPORT_SYMBOL(bioset_integrity_free);
784
785void __init bio_integrity_init(void)
786{
787    unsigned int i;
788
789    /*
790     * kintegrityd won't block much but may burn a lot of CPU cycles.
791     * Make it highpri CPU intensive wq with max concurrency of 1.
792     */
793    kintegrityd_wq = alloc_workqueue("kintegrityd", WQ_MEM_RECLAIM |
794                     WQ_HIGHPRI | WQ_CPU_INTENSIVE, 1);
795    if (!kintegrityd_wq)
796        panic("Failed to create kintegrityd\n");
797
798    for (i = 0 ; i < BIOVEC_NR_POOLS ; i++) {
799        unsigned int size;
800
801        size = sizeof(struct bio_integrity_payload)
802            + bip_slab[i].nr_vecs * sizeof(struct bio_vec);
803
804        bip_slab[i].slab =
805            kmem_cache_create(bip_slab[i].name, size, 0,
806                      SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
807    }
808}
809

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