2 * bio-integrity.c - bio data integrity extensions
4 * Copyright (C) 2007, 2008, 2009 Oracle Corporation
5 * Written by: Martin K. Petersen <martin.petersen@oracle.com>
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.
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.
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,
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>
30 #define BIP_INLINE_VECS 4
32 static struct kmem_cache
*bip_slab
;
33 static struct workqueue_struct
*kintegrityd_wq
;
36 * bio_integrity_alloc - Allocate integrity payload and attach it to bio
37 * @bio: bio to attach integrity metadata to
38 * @gfp_mask: Memory allocation mask
39 * @nr_vecs: Number of integrity metadata scatter-gather elements
41 * Description: This function prepares a bio for attaching integrity
42 * metadata. nr_vecs specifies the maximum number of pages containing
43 * integrity metadata that can be attached.
45 struct bio_integrity_payload
*bio_integrity_alloc(struct bio
*bio
,
49 struct bio_integrity_payload
*bip
;
50 struct bio_set
*bs
= bio
->bi_pool
;
51 unsigned long idx
= BIO_POOL_NONE
;
55 bip
= kmalloc(sizeof(struct bio_integrity_payload
) +
56 sizeof(struct bio_vec
) * nr_vecs
, gfp_mask
);
57 inline_vecs
= nr_vecs
;
59 bip
= mempool_alloc(bs
->bio_integrity_pool
, gfp_mask
);
60 inline_vecs
= BIP_INLINE_VECS
;
66 memset(bip
, 0, sizeof(*bip
));
68 if (nr_vecs
> inline_vecs
) {
69 bip
->bip_vec
= bvec_alloc(gfp_mask
, nr_vecs
, &idx
,
70 bs
->bvec_integrity_pool
);
74 bip
->bip_vec
= bip
->bip_inline_vecs
;
79 bio
->bi_integrity
= bip
;
83 mempool_free(bip
, bs
->bio_integrity_pool
);
86 EXPORT_SYMBOL(bio_integrity_alloc
);
89 * bio_integrity_free - Free bio integrity payload
90 * @bio: bio containing bip to be freed
92 * Description: Used to free the integrity portion of a bio. Usually
93 * called from bio_free().
95 void bio_integrity_free(struct bio
*bio
)
97 struct bio_integrity_payload
*bip
= bio
->bi_integrity
;
98 struct bio_set
*bs
= bio
->bi_pool
;
100 if (bip
->bip_owns_buf
)
104 if (bip
->bip_slab
!= BIO_POOL_NONE
)
105 bvec_free(bs
->bvec_integrity_pool
, bip
->bip_vec
,
108 mempool_free(bip
, bs
->bio_integrity_pool
);
113 bio
->bi_integrity
= NULL
;
115 EXPORT_SYMBOL(bio_integrity_free
);
118 * bio_integrity_add_page - Attach integrity metadata
119 * @bio: bio to update
120 * @page: page containing integrity metadata
121 * @len: number of bytes of integrity metadata in page
122 * @offset: start offset within page
124 * Description: Attach a page containing integrity metadata to bio.
126 int bio_integrity_add_page(struct bio
*bio
, struct page
*page
,
127 unsigned int len
, unsigned int offset
)
129 struct bio_integrity_payload
*bip
= bio
->bi_integrity
;
132 if (bip
->bip_vcnt
>= bvec_nr_vecs(bip
->bip_slab
)) {
133 printk(KERN_ERR
"%s: bip_vec full\n", __func__
);
137 iv
= bip
->bip_vec
+ bip
->bip_vcnt
;
141 iv
->bv_offset
= offset
;
146 EXPORT_SYMBOL(bio_integrity_add_page
);
148 static int bdev_integrity_enabled(struct block_device
*bdev
, int rw
)
150 struct blk_integrity
*bi
= bdev_get_integrity(bdev
);
155 if (rw
== READ
&& bi
->verify_fn
!= NULL
&&
156 (bi
->flags
& INTEGRITY_FLAG_READ
))
159 if (rw
== WRITE
&& bi
->generate_fn
!= NULL
&&
160 (bi
->flags
& INTEGRITY_FLAG_WRITE
))
167 * bio_integrity_enabled - Check whether integrity can be passed
170 * Description: Determines whether bio_integrity_prep() can be called
171 * on this bio or not. bio data direction and target device must be
172 * set prior to calling. The functions honors the write_generate and
173 * read_verify flags in sysfs.
175 int bio_integrity_enabled(struct bio
*bio
)
177 /* Already protected? */
178 if (bio_integrity(bio
))
181 return bdev_integrity_enabled(bio
->bi_bdev
, bio_data_dir(bio
));
183 EXPORT_SYMBOL(bio_integrity_enabled
);
186 * bio_integrity_hw_sectors - Convert 512b sectors to hardware ditto
187 * @bi: blk_integrity profile for device
188 * @sectors: Number of 512 sectors to convert
190 * Description: The block layer calculates everything in 512 byte
191 * sectors but integrity metadata is done in terms of the hardware
192 * sector size of the storage device. Convert the block layer sectors
193 * to physical sectors.
195 static inline unsigned int bio_integrity_hw_sectors(struct blk_integrity
*bi
,
196 unsigned int sectors
)
198 /* At this point there are only 512b or 4096b DIF/EPP devices */
199 if (bi
->sector_size
== 4096)
200 return sectors
>>= 3;
205 static inline unsigned int bio_integrity_bytes(struct blk_integrity
*bi
,
206 unsigned int sectors
)
208 return bio_integrity_hw_sectors(bi
, sectors
) * bi
->tuple_size
;
212 * bio_integrity_tag_size - Retrieve integrity tag space
213 * @bio: bio to inspect
215 * Description: Returns the maximum number of tag bytes that can be
216 * attached to this bio. Filesystems can use this to determine how
217 * much metadata to attach to an I/O.
219 unsigned int bio_integrity_tag_size(struct bio
*bio
)
221 struct blk_integrity
*bi
= bdev_get_integrity(bio
->bi_bdev
);
223 BUG_ON(bio
->bi_iter
.bi_size
== 0);
225 return bi
->tag_size
* (bio
->bi_iter
.bi_size
/ bi
->sector_size
);
227 EXPORT_SYMBOL(bio_integrity_tag_size
);
229 int bio_integrity_tag(struct bio
*bio
, void *tag_buf
, unsigned int len
, int set
)
231 struct bio_integrity_payload
*bip
= bio
->bi_integrity
;
232 struct blk_integrity
*bi
= bdev_get_integrity(bio
->bi_bdev
);
233 unsigned int nr_sectors
;
235 BUG_ON(bip
->bip_buf
== NULL
);
237 if (bi
->tag_size
== 0)
240 nr_sectors
= bio_integrity_hw_sectors(bi
,
241 DIV_ROUND_UP(len
, bi
->tag_size
));
243 if (nr_sectors
* bi
->tuple_size
> bip
->bip_iter
.bi_size
) {
244 printk(KERN_ERR
"%s: tag too big for bio: %u > %u\n", __func__
,
245 nr_sectors
* bi
->tuple_size
, bip
->bip_iter
.bi_size
);
250 bi
->set_tag_fn(bip
->bip_buf
, tag_buf
, nr_sectors
);
252 bi
->get_tag_fn(bip
->bip_buf
, tag_buf
, nr_sectors
);
258 * bio_integrity_set_tag - Attach a tag buffer to a bio
259 * @bio: bio to attach buffer to
260 * @tag_buf: Pointer to a buffer containing tag data
261 * @len: Length of the included buffer
263 * Description: Use this function to tag a bio by leveraging the extra
264 * space provided by devices formatted with integrity protection. The
265 * size of the integrity buffer must be <= to the size reported by
266 * bio_integrity_tag_size().
268 int bio_integrity_set_tag(struct bio
*bio
, void *tag_buf
, unsigned int len
)
270 BUG_ON(bio_data_dir(bio
) != WRITE
);
272 return bio_integrity_tag(bio
, tag_buf
, len
, 1);
274 EXPORT_SYMBOL(bio_integrity_set_tag
);
277 * bio_integrity_get_tag - Retrieve a tag buffer from a bio
278 * @bio: bio to retrieve buffer from
279 * @tag_buf: Pointer to a buffer for the tag data
280 * @len: Length of the target buffer
282 * Description: Use this function to retrieve the tag buffer from a
283 * completed I/O. The size of the integrity buffer must be <= to the
284 * size reported by bio_integrity_tag_size().
286 int bio_integrity_get_tag(struct bio
*bio
, void *tag_buf
, unsigned int len
)
288 BUG_ON(bio_data_dir(bio
) != READ
);
290 return bio_integrity_tag(bio
, tag_buf
, len
, 0);
292 EXPORT_SYMBOL(bio_integrity_get_tag
);
295 * bio_integrity_generate - Generate integrity metadata for a bio
296 * @bio: bio to generate integrity metadata for
298 * Description: Generates integrity metadata for a bio by calling the
299 * block device's generation callback function. The bio must have a
300 * bip attached with enough room to accommodate the generated
301 * integrity metadata.
303 static void bio_integrity_generate(struct bio
*bio
)
305 struct blk_integrity
*bi
= bdev_get_integrity(bio
->bi_bdev
);
306 struct blk_integrity_exchg bix
;
308 struct bvec_iter iter
;
309 sector_t sector
= bio
->bi_iter
.bi_sector
;
310 unsigned int sectors
, total
;
311 void *prot_buf
= bio
->bi_integrity
->bip_buf
;
314 bix
.disk_name
= bio
->bi_bdev
->bd_disk
->disk_name
;
315 bix
.sector_size
= bi
->sector_size
;
317 bio_for_each_segment(bv
, bio
, iter
) {
318 void *kaddr
= kmap_atomic(bv
.bv_page
);
319 bix
.data_buf
= kaddr
+ bv
.bv_offset
;
320 bix
.data_size
= bv
.bv_len
;
321 bix
.prot_buf
= prot_buf
;
324 bi
->generate_fn(&bix
);
326 sectors
= bv
.bv_len
/ bi
->sector_size
;
328 prot_buf
+= sectors
* bi
->tuple_size
;
329 total
+= sectors
* bi
->tuple_size
;
330 BUG_ON(total
> bio
->bi_integrity
->bip_iter
.bi_size
);
332 kunmap_atomic(kaddr
);
336 static inline unsigned short blk_integrity_tuple_size(struct blk_integrity
*bi
)
339 return bi
->tuple_size
;
345 * bio_integrity_prep - Prepare bio for integrity I/O
346 * @bio: bio to prepare
348 * Description: Allocates a buffer for integrity metadata, maps the
349 * pages and attaches them to a bio. The bio must have data
350 * direction, target device and start sector set priot to calling. In
351 * the WRITE case, integrity metadata will be generated using the
352 * block device's integrity function. In the READ case, the buffer
353 * will be prepared for DMA and a suitable end_io handler set up.
355 int bio_integrity_prep(struct bio
*bio
)
357 struct bio_integrity_payload
*bip
;
358 struct blk_integrity
*bi
;
359 struct request_queue
*q
;
361 unsigned long start
, end
;
362 unsigned int len
, nr_pages
;
363 unsigned int bytes
, offset
, i
;
364 unsigned int sectors
;
366 bi
= bdev_get_integrity(bio
->bi_bdev
);
367 q
= bdev_get_queue(bio
->bi_bdev
);
369 BUG_ON(bio_integrity(bio
));
371 sectors
= bio_integrity_hw_sectors(bi
, bio_sectors(bio
));
373 /* Allocate kernel buffer for protection data */
374 len
= sectors
* blk_integrity_tuple_size(bi
);
375 buf
= kmalloc(len
, GFP_NOIO
| q
->bounce_gfp
);
376 if (unlikely(buf
== NULL
)) {
377 printk(KERN_ERR
"could not allocate integrity buffer\n");
381 end
= (((unsigned long) buf
) + len
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
382 start
= ((unsigned long) buf
) >> PAGE_SHIFT
;
383 nr_pages
= end
- start
;
385 /* Allocate bio integrity payload and integrity vectors */
386 bip
= bio_integrity_alloc(bio
, GFP_NOIO
, nr_pages
);
387 if (unlikely(bip
== NULL
)) {
388 printk(KERN_ERR
"could not allocate data integrity bioset\n");
393 bip
->bip_owns_buf
= 1;
395 bip
->bip_iter
.bi_size
= len
;
396 bip
->bip_iter
.bi_sector
= bio
->bi_iter
.bi_sector
;
399 offset
= offset_in_page(buf
);
400 for (i
= 0 ; i
< nr_pages
; i
++) {
402 bytes
= PAGE_SIZE
- offset
;
410 ret
= bio_integrity_add_page(bio
, virt_to_page(buf
),
424 /* Install custom I/O completion handler if read verify is enabled */
425 if (bio_data_dir(bio
) == READ
) {
426 bip
->bip_end_io
= bio
->bi_end_io
;
427 bio
->bi_end_io
= bio_integrity_endio
;
430 /* Auto-generate integrity metadata if this is a write */
431 if (bio_data_dir(bio
) == WRITE
)
432 bio_integrity_generate(bio
);
436 EXPORT_SYMBOL(bio_integrity_prep
);
439 * bio_integrity_verify - Verify integrity metadata for a bio
440 * @bio: bio to verify
442 * Description: This function is called to verify the integrity of a
443 * bio. The data in the bio io_vec is compared to the integrity
444 * metadata returned by the HBA.
446 static int bio_integrity_verify(struct bio
*bio
)
448 struct blk_integrity
*bi
= bdev_get_integrity(bio
->bi_bdev
);
449 struct blk_integrity_exchg bix
;
451 struct bvec_iter iter
;
452 sector_t sector
= bio
->bi_integrity
->bip_iter
.bi_sector
;
453 unsigned int sectors
, total
, ret
;
454 void *prot_buf
= bio
->bi_integrity
->bip_buf
;
457 bix
.disk_name
= bio
->bi_bdev
->bd_disk
->disk_name
;
458 bix
.sector_size
= bi
->sector_size
;
460 bio_for_each_segment(bv
, bio
, iter
) {
461 void *kaddr
= kmap_atomic(bv
.bv_page
);
462 bix
.data_buf
= kaddr
+ bv
.bv_offset
;
463 bix
.data_size
= bv
.bv_len
;
464 bix
.prot_buf
= prot_buf
;
467 ret
= bi
->verify_fn(&bix
);
470 kunmap_atomic(kaddr
);
474 sectors
= bv
.bv_len
/ bi
->sector_size
;
476 prot_buf
+= sectors
* bi
->tuple_size
;
477 total
+= sectors
* bi
->tuple_size
;
478 BUG_ON(total
> bio
->bi_integrity
->bip_iter
.bi_size
);
480 kunmap_atomic(kaddr
);
487 * bio_integrity_verify_fn - Integrity I/O completion worker
488 * @work: Work struct stored in bio to be verified
490 * Description: This workqueue function is called to complete a READ
491 * request. The function verifies the transferred integrity metadata
492 * and then calls the original bio end_io function.
494 static void bio_integrity_verify_fn(struct work_struct
*work
)
496 struct bio_integrity_payload
*bip
=
497 container_of(work
, struct bio_integrity_payload
, bip_work
);
498 struct bio
*bio
= bip
->bip_bio
;
501 error
= bio_integrity_verify(bio
);
503 /* Restore original bio completion handler */
504 bio
->bi_end_io
= bip
->bip_end_io
;
505 bio_endio(bio
, error
);
509 * bio_integrity_endio - Integrity I/O completion function
510 * @bio: Protected bio
511 * @error: Pointer to errno
513 * Description: Completion for integrity I/O
515 * Normally I/O completion is done in interrupt context. However,
516 * verifying I/O integrity is a time-consuming task which must be run
517 * in process context. This function postpones completion
520 void bio_integrity_endio(struct bio
*bio
, int error
)
522 struct bio_integrity_payload
*bip
= bio
->bi_integrity
;
524 BUG_ON(bip
->bip_bio
!= bio
);
526 /* In case of an I/O error there is no point in verifying the
527 * integrity metadata. Restore original bio end_io handler
531 bio
->bi_end_io
= bip
->bip_end_io
;
532 bio_endio(bio
, error
);
537 INIT_WORK(&bip
->bip_work
, bio_integrity_verify_fn
);
538 queue_work(kintegrityd_wq
, &bip
->bip_work
);
540 EXPORT_SYMBOL(bio_integrity_endio
);
543 * bio_integrity_advance - Advance integrity vector
544 * @bio: bio whose integrity vector to update
545 * @bytes_done: number of data bytes that have been completed
547 * Description: This function calculates how many integrity bytes the
548 * number of completed data bytes correspond to and advances the
549 * integrity vector accordingly.
551 void bio_integrity_advance(struct bio
*bio
, unsigned int bytes_done
)
553 struct bio_integrity_payload
*bip
= bio
->bi_integrity
;
554 struct blk_integrity
*bi
= bdev_get_integrity(bio
->bi_bdev
);
555 unsigned bytes
= bio_integrity_bytes(bi
, bytes_done
>> 9);
557 bvec_iter_advance(bip
->bip_vec
, &bip
->bip_iter
, bytes
);
559 EXPORT_SYMBOL(bio_integrity_advance
);
562 * bio_integrity_trim - Trim integrity vector
563 * @bio: bio whose integrity vector to update
564 * @offset: offset to first data sector
565 * @sectors: number of data sectors
567 * Description: Used to trim the integrity vector in a cloned bio.
568 * The ivec will be advanced corresponding to 'offset' data sectors
569 * and the length will be truncated corresponding to 'len' data
572 void bio_integrity_trim(struct bio
*bio
, unsigned int offset
,
573 unsigned int sectors
)
575 struct bio_integrity_payload
*bip
= bio
->bi_integrity
;
576 struct blk_integrity
*bi
= bdev_get_integrity(bio
->bi_bdev
);
578 bio_integrity_advance(bio
, offset
<< 9);
579 bip
->bip_iter
.bi_size
= bio_integrity_bytes(bi
, sectors
);
581 EXPORT_SYMBOL(bio_integrity_trim
);
584 * bio_integrity_split - Split integrity metadata
585 * @bio: Protected bio
586 * @bp: Resulting bio_pair
589 * Description: Splits an integrity page into a bio_pair.
591 void bio_integrity_split(struct bio
*bio
, struct bio_pair
*bp
, int sectors
)
593 struct blk_integrity
*bi
;
594 struct bio_integrity_payload
*bip
= bio
->bi_integrity
;
595 unsigned int nr_sectors
;
597 if (bio_integrity(bio
) == 0)
600 bi
= bdev_get_integrity(bio
->bi_bdev
);
602 BUG_ON(bip
->bip_vcnt
!= 1);
604 nr_sectors
= bio_integrity_hw_sectors(bi
, sectors
);
606 bp
->bio1
.bi_integrity
= &bp
->bip1
;
607 bp
->bio2
.bi_integrity
= &bp
->bip2
;
609 bp
->iv1
= bip
->bip_vec
[bip
->bip_iter
.bi_idx
];
610 bp
->iv2
= bip
->bip_vec
[bip
->bip_iter
.bi_idx
];
612 bp
->bip1
.bip_vec
= &bp
->iv1
;
613 bp
->bip2
.bip_vec
= &bp
->iv2
;
615 bp
->iv1
.bv_len
= sectors
* bi
->tuple_size
;
616 bp
->iv2
.bv_offset
+= sectors
* bi
->tuple_size
;
617 bp
->iv2
.bv_len
-= sectors
* bi
->tuple_size
;
619 bp
->bip1
.bip_iter
.bi_sector
= bio
->bi_integrity
->bip_iter
.bi_sector
;
620 bp
->bip2
.bip_iter
.bi_sector
=
621 bio
->bi_integrity
->bip_iter
.bi_sector
+ nr_sectors
;
623 bp
->bip1
.bip_vcnt
= bp
->bip2
.bip_vcnt
= 1;
624 bp
->bip1
.bip_iter
.bi_idx
= bp
->bip2
.bip_iter
.bi_idx
= 0;
626 EXPORT_SYMBOL(bio_integrity_split
);
629 * bio_integrity_clone - Callback for cloning bios with integrity metadata
631 * @bio_src: Original bio
632 * @gfp_mask: Memory allocation mask
634 * Description: Called to allocate a bip when cloning a bio
636 int bio_integrity_clone(struct bio
*bio
, struct bio
*bio_src
,
639 struct bio_integrity_payload
*bip_src
= bio_src
->bi_integrity
;
640 struct bio_integrity_payload
*bip
;
642 BUG_ON(bip_src
== NULL
);
644 bip
= bio_integrity_alloc(bio
, gfp_mask
, bip_src
->bip_vcnt
);
649 memcpy(bip
->bip_vec
, bip_src
->bip_vec
,
650 bip_src
->bip_vcnt
* sizeof(struct bio_vec
));
652 bip
->bip_vcnt
= bip_src
->bip_vcnt
;
653 bip
->bip_iter
= bip_src
->bip_iter
;
657 EXPORT_SYMBOL(bio_integrity_clone
);
659 int bioset_integrity_create(struct bio_set
*bs
, int pool_size
)
661 if (bs
->bio_integrity_pool
)
664 bs
->bio_integrity_pool
= mempool_create_slab_pool(pool_size
, bip_slab
);
665 if (!bs
->bio_integrity_pool
)
668 bs
->bvec_integrity_pool
= biovec_create_pool(bs
, pool_size
);
669 if (!bs
->bvec_integrity_pool
) {
670 mempool_destroy(bs
->bio_integrity_pool
);
676 EXPORT_SYMBOL(bioset_integrity_create
);
678 void bioset_integrity_free(struct bio_set
*bs
)
680 if (bs
->bio_integrity_pool
)
681 mempool_destroy(bs
->bio_integrity_pool
);
683 if (bs
->bvec_integrity_pool
)
684 mempool_destroy(bs
->bvec_integrity_pool
);
686 EXPORT_SYMBOL(bioset_integrity_free
);
688 void __init
bio_integrity_init(void)
691 * kintegrityd won't block much but may burn a lot of CPU cycles.
692 * Make it highpri CPU intensive wq with max concurrency of 1.
694 kintegrityd_wq
= alloc_workqueue("kintegrityd", WQ_MEM_RECLAIM
|
695 WQ_HIGHPRI
| WQ_CPU_INTENSIVE
, 1);
697 panic("Failed to create kintegrityd\n");
699 bip_slab
= kmem_cache_create("bio_integrity_payload",
700 sizeof(struct bio_integrity_payload
) +
701 sizeof(struct bio_vec
) * BIP_INLINE_VECS
,
702 0, SLAB_HWCACHE_ALIGN
|SLAB_PANIC
, NULL
);
704 panic("Failed to create slab\n");
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