Root/
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 | |
29 | struct 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) } |
36 | struct 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 | |
41 | static struct workqueue_struct *kintegrityd_wq; |
42 | |
43 | static 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 | |
63 | static 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 | */ |
82 | struct 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 | } |
116 | EXPORT_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 | */ |
128 | struct 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 | } |
134 | EXPORT_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 | */ |
144 | void 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 | } |
162 | EXPORT_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 | */ |
173 | int 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 | } |
194 | EXPORT_SYMBOL(bio_integrity_add_page); |
195 | |
196 | static 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 | */ |
223 | int 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 | } |
231 | EXPORT_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 | */ |
243 | static 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 | */ |
261 | unsigned 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 | } |
269 | EXPORT_SYMBOL(bio_integrity_tag_size); |
270 | |
271 | int 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 | */ |
310 | int 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 | } |
316 | EXPORT_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 | */ |
328 | int 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 | } |
334 | EXPORT_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 | */ |
345 | static 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 | |
377 | static 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 | */ |
396 | int 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 | } |
476 | EXPORT_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 | */ |
486 | static 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 | */ |
533 | static 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 | */ |
559 | void 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 | } |
579 | EXPORT_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 | */ |
586 | void 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 | */ |
612 | void 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 | */ |
640 | void 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 | } |
652 | EXPORT_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 | */ |
665 | void 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 | } |
681 | EXPORT_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 | */ |
691 | void 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 | } |
725 | EXPORT_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 | */ |
736 | int 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 | } |
758 | EXPORT_SYMBOL(bio_integrity_clone); |
759 | |
760 | int 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 | } |
772 | EXPORT_SYMBOL(bioset_integrity_create); |
773 | |
774 | void bioset_integrity_free(struct bio_set *bs) |
775 | { |
776 | if (bs->bio_integrity_pool) |
777 | mempool_destroy(bs->bio_integrity_pool); |
778 | } |
779 | EXPORT_SYMBOL(bioset_integrity_free); |
780 | |
781 | void __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 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9