1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
|
// SPDX-License-Identifier: GPL-2.0
/*
* bio-integrity.c - bio data integrity extensions
*
* Copyright (C) 2007, 2008, 2009 Oracle Corporation
* Written by: Martin K. Petersen <martin.petersen@oracle.com>
*/
#include <linux/blk-integrity.h>
#include <linux/mempool.h>
#include <linux/export.h>
#include <linux/bio.h>
#include <linux/workqueue.h>
#include <linux/slab.h>
#include "blk.h"
static struct kmem_cache *bip_slab;
static struct workqueue_struct *kintegrityd_wq;
void blk_flush_integrity(void)
{
flush_workqueue(kintegrityd_wq);
}
/**
* bio_integrity_free - Free bio integrity payload
* @bio: bio containing bip to be freed
*
* Description: Free the integrity portion of a bio.
*/
void bio_integrity_free(struct bio *bio)
{
struct bio_integrity_payload *bip = bio_integrity(bio);
struct bio_set *bs = bio->bi_pool;
if (bs && mempool_initialized(&bs->bio_integrity_pool)) {
if (bip->bip_vec)
bvec_free(&bs->bvec_integrity_pool, bip->bip_vec,
bip->bip_max_vcnt);
mempool_free(bip, &bs->bio_integrity_pool);
} else {
kfree(bip);
}
bio->bi_integrity = NULL;
bio->bi_opf &= ~REQ_INTEGRITY;
}
/**
* bio_integrity_alloc - Allocate integrity payload and attach it to bio
* @bio: bio to attach integrity metadata to
* @gfp_mask: Memory allocation mask
* @nr_vecs: Number of integrity metadata scatter-gather elements
*
* Description: This function prepares a bio for attaching integrity
* metadata. nr_vecs specifies the maximum number of pages containing
* integrity metadata that can be attached.
*/
struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
gfp_t gfp_mask,
unsigned int nr_vecs)
{
struct bio_integrity_payload *bip;
struct bio_set *bs = bio->bi_pool;
unsigned inline_vecs;
if (WARN_ON_ONCE(bio_has_crypt_ctx(bio)))
return ERR_PTR(-EOPNOTSUPP);
if (!bs || !mempool_initialized(&bs->bio_integrity_pool)) {
bip = kmalloc(struct_size(bip, bip_inline_vecs, nr_vecs), gfp_mask);
inline_vecs = nr_vecs;
} else {
bip = mempool_alloc(&bs->bio_integrity_pool, gfp_mask);
inline_vecs = BIO_INLINE_VECS;
}
if (unlikely(!bip))
return ERR_PTR(-ENOMEM);
memset(bip, 0, sizeof(*bip));
/* always report as many vecs as asked explicitly, not inline vecs */
bip->bip_max_vcnt = nr_vecs;
if (nr_vecs > inline_vecs) {
bip->bip_vec = bvec_alloc(&bs->bvec_integrity_pool,
&bip->bip_max_vcnt, gfp_mask);
if (!bip->bip_vec)
goto err;
} else if (nr_vecs) {
bip->bip_vec = bip->bip_inline_vecs;
}
bip->bip_bio = bio;
bio->bi_integrity = bip;
bio->bi_opf |= REQ_INTEGRITY;
return bip;
err:
if (bs && mempool_initialized(&bs->bio_integrity_pool))
mempool_free(bip, &bs->bio_integrity_pool);
else
kfree(bip);
return ERR_PTR(-ENOMEM);
}
EXPORT_SYMBOL(bio_integrity_alloc);
static void bio_integrity_unpin_bvec(struct bio_vec *bv, int nr_vecs,
bool dirty)
{
int i;
for (i = 0; i < nr_vecs; i++) {
if (dirty && !PageCompound(bv[i].bv_page))
set_page_dirty_lock(bv[i].bv_page);
unpin_user_page(bv[i].bv_page);
}
}
static void bio_integrity_uncopy_user(struct bio_integrity_payload *bip)
{
unsigned short nr_vecs = bip->bip_max_vcnt - 1;
struct bio_vec *copy = &bip->bip_vec[1];
size_t bytes = bip->bip_iter.bi_size;
struct iov_iter iter;
int ret;
iov_iter_bvec(&iter, ITER_DEST, copy, nr_vecs, bytes);
ret = copy_to_iter(bvec_virt(bip->bip_vec), bytes, &iter);
WARN_ON_ONCE(ret != bytes);
bio_integrity_unpin_bvec(copy, nr_vecs, true);
}
/**
* bio_integrity_unmap_user - Unmap user integrity payload
* @bio: bio containing bip to be unmapped
*
* Unmap the user mapped integrity portion of a bio.
*/
void bio_integrity_unmap_user(struct bio *bio)
{
struct bio_integrity_payload *bip = bio_integrity(bio);
if (bip->bip_flags & BIP_COPY_USER) {
if (bio_data_dir(bio) == READ)
bio_integrity_uncopy_user(bip);
kfree(bvec_virt(bip->bip_vec));
return;
}
bio_integrity_unpin_bvec(bip->bip_vec, bip->bip_max_vcnt,
bio_data_dir(bio) == READ);
}
/**
* bio_integrity_add_page - Attach integrity metadata
* @bio: bio to update
* @page: page containing integrity metadata
* @len: number of bytes of integrity metadata in page
* @offset: start offset within page
*
* Description: Attach a page containing integrity metadata to bio.
*/
int bio_integrity_add_page(struct bio *bio, struct page *page,
unsigned int len, unsigned int offset)
{
struct request_queue *q = bdev_get_queue(bio->bi_bdev);
struct bio_integrity_payload *bip = bio_integrity(bio);
if (bip->bip_vcnt > 0) {
struct bio_vec *bv = &bip->bip_vec[bip->bip_vcnt - 1];
bool same_page = false;
if (bvec_try_merge_hw_page(q, bv, page, len, offset,
&same_page)) {
bip->bip_iter.bi_size += len;
return len;
}
if (bip->bip_vcnt >=
min(bip->bip_max_vcnt, queue_max_integrity_segments(q)))
return 0;
/*
* If the queue doesn't support SG gaps and adding this segment
* would create a gap, disallow it.
*/
if (bvec_gap_to_prev(&q->limits, bv, offset))
return 0;
}
bvec_set_page(&bip->bip_vec[bip->bip_vcnt], page, len, offset);
bip->bip_vcnt++;
bip->bip_iter.bi_size += len;
return len;
}
EXPORT_SYMBOL(bio_integrity_add_page);
static int bio_integrity_copy_user(struct bio *bio, struct bio_vec *bvec,
int nr_vecs, unsigned int len,
unsigned int direction)
{
bool write = direction == ITER_SOURCE;
struct bio_integrity_payload *bip;
struct iov_iter iter;
void *buf;
int ret;
buf = kmalloc(len, GFP_KERNEL);
if (!buf)
return -ENOMEM;
if (write) {
iov_iter_bvec(&iter, direction, bvec, nr_vecs, len);
if (!copy_from_iter_full(buf, len, &iter)) {
ret = -EFAULT;
goto free_buf;
}
bip = bio_integrity_alloc(bio, GFP_KERNEL, 1);
} else {
memset(buf, 0, len);
/*
* We need to preserve the original bvec and the number of vecs
* in it for completion handling
*/
bip = bio_integrity_alloc(bio, GFP_KERNEL, nr_vecs + 1);
}
if (IS_ERR(bip)) {
ret = PTR_ERR(bip);
goto free_buf;
}
if (write)
bio_integrity_unpin_bvec(bvec, nr_vecs, false);
else
memcpy(&bip->bip_vec[1], bvec, nr_vecs * sizeof(*bvec));
ret = bio_integrity_add_page(bio, virt_to_page(buf), len,
offset_in_page(buf));
if (ret != len) {
ret = -ENOMEM;
goto free_bip;
}
bip->bip_flags |= BIP_COPY_USER;
bip->bip_vcnt = nr_vecs;
return 0;
free_bip:
bio_integrity_free(bio);
free_buf:
kfree(buf);
return ret;
}
static int bio_integrity_init_user(struct bio *bio, struct bio_vec *bvec,
int nr_vecs, unsigned int len)
{
struct bio_integrity_payload *bip;
bip = bio_integrity_alloc(bio, GFP_KERNEL, nr_vecs);
if (IS_ERR(bip))
return PTR_ERR(bip);
memcpy(bip->bip_vec, bvec, nr_vecs * sizeof(*bvec));
bip->bip_iter.bi_size = len;
bip->bip_vcnt = nr_vecs;
return 0;
}
static unsigned int bvec_from_pages(struct bio_vec *bvec, struct page **pages,
int nr_vecs, ssize_t bytes, ssize_t offset)
{
unsigned int nr_bvecs = 0;
int i, j;
for (i = 0; i < nr_vecs; i = j) {
size_t size = min_t(size_t, bytes, PAGE_SIZE - offset);
struct folio *folio = page_folio(pages[i]);
bytes -= size;
for (j = i + 1; j < nr_vecs; j++) {
size_t next = min_t(size_t, PAGE_SIZE, bytes);
if (page_folio(pages[j]) != folio ||
pages[j] != pages[j - 1] + 1)
break;
unpin_user_page(pages[j]);
size += next;
bytes -= next;
}
bvec_set_page(&bvec[nr_bvecs], pages[i], size, offset);
offset = 0;
nr_bvecs++;
}
return nr_bvecs;
}
int bio_integrity_map_user(struct bio *bio, void __user *ubuf, ssize_t bytes)
{
struct request_queue *q = bdev_get_queue(bio->bi_bdev);
unsigned int align = blk_lim_dma_alignment_and_pad(&q->limits);
struct page *stack_pages[UIO_FASTIOV], **pages = stack_pages;
struct bio_vec stack_vec[UIO_FASTIOV], *bvec = stack_vec;
unsigned int direction, nr_bvecs;
struct iov_iter iter;
int ret, nr_vecs;
size_t offset;
bool copy;
if (bio_integrity(bio))
return -EINVAL;
if (bytes >> SECTOR_SHIFT > queue_max_hw_sectors(q))
return -E2BIG;
if (bio_data_dir(bio) == READ)
direction = ITER_DEST;
else
direction = ITER_SOURCE;
iov_iter_ubuf(&iter, direction, ubuf, bytes);
nr_vecs = iov_iter_npages(&iter, BIO_MAX_VECS + 1);
if (nr_vecs > BIO_MAX_VECS)
return -E2BIG;
if (nr_vecs > UIO_FASTIOV) {
bvec = kcalloc(nr_vecs, sizeof(*bvec), GFP_KERNEL);
if (!bvec)
return -ENOMEM;
pages = NULL;
}
copy = !iov_iter_is_aligned(&iter, align, align);
ret = iov_iter_extract_pages(&iter, &pages, bytes, nr_vecs, 0, &offset);
if (unlikely(ret < 0))
goto free_bvec;
nr_bvecs = bvec_from_pages(bvec, pages, nr_vecs, bytes, offset);
if (pages != stack_pages)
kvfree(pages);
if (nr_bvecs > queue_max_integrity_segments(q))
copy = true;
if (copy)
ret = bio_integrity_copy_user(bio, bvec, nr_bvecs, bytes,
direction);
else
ret = bio_integrity_init_user(bio, bvec, nr_bvecs, bytes);
if (ret)
goto release_pages;
if (bvec != stack_vec)
kfree(bvec);
return 0;
release_pages:
bio_integrity_unpin_bvec(bvec, nr_bvecs, false);
free_bvec:
if (bvec != stack_vec)
kfree(bvec);
return ret;
}
/**
* bio_integrity_prep - Prepare bio for integrity I/O
* @bio: bio to prepare
*
* Description: Checks if the bio already has an integrity payload attached.
* If it does, the payload has been generated by another kernel subsystem,
* and we just pass it through. Otherwise allocates integrity payload.
* The bio must have data direction, target device and start sector set priot
* to calling. In the WRITE case, integrity metadata will be generated using
* the block device's integrity function. In the READ case, the buffer
* will be prepared for DMA and a suitable end_io handler set up.
*/
bool bio_integrity_prep(struct bio *bio)
{
struct bio_integrity_payload *bip;
struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
unsigned int len;
void *buf;
gfp_t gfp = GFP_NOIO;
if (!bi)
return true;
if (!bio_sectors(bio))
return true;
/* Already protected? */
if (bio_integrity(bio))
return true;
switch (bio_op(bio)) {
case REQ_OP_READ:
if (bi->flags & BLK_INTEGRITY_NOVERIFY)
return true;
break;
case REQ_OP_WRITE:
if (bi->flags & BLK_INTEGRITY_NOGENERATE)
return true;
/*
* Zero the memory allocated to not leak uninitialized kernel
* memory to disk for non-integrity metadata where nothing else
* initializes the memory.
*/
if (bi->csum_type == BLK_INTEGRITY_CSUM_NONE)
gfp |= __GFP_ZERO;
break;
default:
return true;
}
/* Allocate kernel buffer for protection data */
len = bio_integrity_bytes(bi, bio_sectors(bio));
buf = kmalloc(len, gfp);
if (unlikely(buf == NULL)) {
goto err_end_io;
}
bip = bio_integrity_alloc(bio, GFP_NOIO, 1);
if (IS_ERR(bip)) {
kfree(buf);
goto err_end_io;
}
bip->bip_flags |= BIP_BLOCK_INTEGRITY;
bip_set_seed(bip, bio->bi_iter.bi_sector);
if (bi->csum_type == BLK_INTEGRITY_CSUM_IP)
bip->bip_flags |= BIP_IP_CHECKSUM;
if (bio_integrity_add_page(bio, virt_to_page(buf), len,
offset_in_page(buf)) < len) {
printk(KERN_ERR "could not attach integrity payload\n");
goto err_end_io;
}
/* Auto-generate integrity metadata if this is a write */
if (bio_data_dir(bio) == WRITE)
blk_integrity_generate(bio);
else
bip->bio_iter = bio->bi_iter;
return true;
err_end_io:
bio->bi_status = BLK_STS_RESOURCE;
bio_endio(bio);
return false;
}
EXPORT_SYMBOL(bio_integrity_prep);
/**
* bio_integrity_verify_fn - Integrity I/O completion worker
* @work: Work struct stored in bio to be verified
*
* Description: This workqueue function is called to complete a READ
* request. The function verifies the transferred integrity metadata
* and then calls the original bio end_io function.
*/
static void bio_integrity_verify_fn(struct work_struct *work)
{
struct bio_integrity_payload *bip =
container_of(work, struct bio_integrity_payload, bip_work);
struct bio *bio = bip->bip_bio;
blk_integrity_verify(bio);
kfree(bvec_virt(bip->bip_vec));
bio_integrity_free(bio);
bio_endio(bio);
}
/**
* __bio_integrity_endio - Integrity I/O completion function
* @bio: Protected bio
*
* Description: Completion for integrity I/O
*
* Normally I/O completion is done in interrupt context. However,
* verifying I/O integrity is a time-consuming task which must be run
* in process context. This function postpones completion
* accordingly.
*/
bool __bio_integrity_endio(struct bio *bio)
{
struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
struct bio_integrity_payload *bip = bio_integrity(bio);
if (bio_op(bio) == REQ_OP_READ && !bio->bi_status && bi->csum_type) {
INIT_WORK(&bip->bip_work, bio_integrity_verify_fn);
queue_work(kintegrityd_wq, &bip->bip_work);
return false;
}
kfree(bvec_virt(bip->bip_vec));
bio_integrity_free(bio);
return true;
}
/**
* bio_integrity_advance - Advance integrity vector
* @bio: bio whose integrity vector to update
* @bytes_done: number of data bytes that have been completed
*
* Description: This function calculates how many integrity bytes the
* number of completed data bytes correspond to and advances the
* integrity vector accordingly.
*/
void bio_integrity_advance(struct bio *bio, unsigned int bytes_done)
{
struct bio_integrity_payload *bip = bio_integrity(bio);
struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
unsigned bytes = bio_integrity_bytes(bi, bytes_done >> 9);
bip->bip_iter.bi_sector += bio_integrity_intervals(bi, bytes_done >> 9);
bvec_iter_advance(bip->bip_vec, &bip->bip_iter, bytes);
}
/**
* bio_integrity_trim - Trim integrity vector
* @bio: bio whose integrity vector to update
*
* Description: Used to trim the integrity vector in a cloned bio.
*/
void bio_integrity_trim(struct bio *bio)
{
struct bio_integrity_payload *bip = bio_integrity(bio);
struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
bip->bip_iter.bi_size = bio_integrity_bytes(bi, bio_sectors(bio));
}
EXPORT_SYMBOL(bio_integrity_trim);
/**
* bio_integrity_clone - Callback for cloning bios with integrity metadata
* @bio: New bio
* @bio_src: Original bio
* @gfp_mask: Memory allocation mask
*
* Description: Called to allocate a bip when cloning a bio
*/
int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
gfp_t gfp_mask)
{
struct bio_integrity_payload *bip_src = bio_integrity(bio_src);
struct bio_integrity_payload *bip;
BUG_ON(bip_src == NULL);
bip = bio_integrity_alloc(bio, gfp_mask, 0);
if (IS_ERR(bip))
return PTR_ERR(bip);
bip->bip_vec = bip_src->bip_vec;
bip->bip_iter = bip_src->bip_iter;
bip->bip_flags = bip_src->bip_flags & ~BIP_BLOCK_INTEGRITY;
return 0;
}
int bioset_integrity_create(struct bio_set *bs, int pool_size)
{
if (mempool_initialized(&bs->bio_integrity_pool))
return 0;
if (mempool_init_slab_pool(&bs->bio_integrity_pool,
pool_size, bip_slab))
return -1;
if (biovec_init_pool(&bs->bvec_integrity_pool, pool_size)) {
mempool_exit(&bs->bio_integrity_pool);
return -1;
}
return 0;
}
EXPORT_SYMBOL(bioset_integrity_create);
void bioset_integrity_free(struct bio_set *bs)
{
mempool_exit(&bs->bio_integrity_pool);
mempool_exit(&bs->bvec_integrity_pool);
}
void __init bio_integrity_init(void)
{
/*
* kintegrityd won't block much but may burn a lot of CPU cycles.
* Make it highpri CPU intensive wq with max concurrency of 1.
*/
kintegrityd_wq = alloc_workqueue("kintegrityd", WQ_MEM_RECLAIM |
WQ_HIGHPRI | WQ_CPU_INTENSIVE, 1);
if (!kintegrityd_wq)
panic("Failed to create kintegrityd\n");
bip_slab = kmem_cache_create("bio_integrity_payload",
sizeof(struct bio_integrity_payload) +
sizeof(struct bio_vec) * BIO_INLINE_VECS,
0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
}
|