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
;
35 void blk_flush_integrity(void)
37 flush_workqueue(kintegrityd_wq
);
41 * bio_integrity_alloc - Allocate integrity payload and attach it to bio
42 * @bio: bio to attach integrity metadata to
43 * @gfp_mask: Memory allocation mask
44 * @nr_vecs: Number of integrity metadata scatter-gather elements
46 * Description: This function prepares a bio for attaching integrity
47 * metadata. nr_vecs specifies the maximum number of pages containing
48 * integrity metadata that can be attached.
50 struct bio_integrity_payload
*bio_integrity_alloc(struct bio
*bio
,
54 struct bio_integrity_payload
*bip
;
55 struct bio_set
*bs
= bio
->bi_pool
;
58 if (!bs
|| !bs
->bio_integrity_pool
) {
59 bip
= kmalloc(sizeof(struct bio_integrity_payload
) +
60 sizeof(struct bio_vec
) * nr_vecs
, gfp_mask
);
61 inline_vecs
= nr_vecs
;
63 bip
= mempool_alloc(bs
->bio_integrity_pool
, gfp_mask
);
64 inline_vecs
= BIP_INLINE_VECS
;
68 return ERR_PTR(-ENOMEM
);
70 memset(bip
, 0, sizeof(*bip
));
72 if (nr_vecs
> inline_vecs
) {
73 unsigned long idx
= 0;
75 bip
->bip_vec
= bvec_alloc(gfp_mask
, nr_vecs
, &idx
,
76 bs
->bvec_integrity_pool
);
79 bip
->bip_max_vcnt
= bvec_nr_vecs(idx
);
82 bip
->bip_vec
= bip
->bip_inline_vecs
;
83 bip
->bip_max_vcnt
= inline_vecs
;
87 bio
->bi_integrity
= bip
;
88 bio
->bi_rw
|= REQ_INTEGRITY
;
92 mempool_free(bip
, bs
->bio_integrity_pool
);
93 return ERR_PTR(-ENOMEM
);
95 EXPORT_SYMBOL(bio_integrity_alloc
);
98 * bio_integrity_free - Free bio integrity payload
99 * @bio: bio containing bip to be freed
101 * Description: Used to free the integrity portion of a bio. Usually
102 * called from bio_free().
104 void bio_integrity_free(struct bio
*bio
)
106 struct bio_integrity_payload
*bip
= bio_integrity(bio
);
107 struct bio_set
*bs
= bio
->bi_pool
;
109 if (bip
->bip_flags
& BIP_BLOCK_INTEGRITY
)
110 kfree(page_address(bip
->bip_vec
->bv_page
) +
111 bip
->bip_vec
->bv_offset
);
113 if (bs
&& bs
->bio_integrity_pool
) {
114 bvec_free(bs
->bvec_integrity_pool
, bip
->bip_vec
, bip
->bip_slab
);
116 mempool_free(bip
, bs
->bio_integrity_pool
);
121 bio
->bi_integrity
= NULL
;
123 EXPORT_SYMBOL(bio_integrity_free
);
126 * bio_integrity_add_page - Attach integrity metadata
127 * @bio: bio to update
128 * @page: page containing integrity metadata
129 * @len: number of bytes of integrity metadata in page
130 * @offset: start offset within page
132 * Description: Attach a page containing integrity metadata to bio.
134 int bio_integrity_add_page(struct bio
*bio
, struct page
*page
,
135 unsigned int len
, unsigned int offset
)
137 struct bio_integrity_payload
*bip
= bio_integrity(bio
);
140 if (bip
->bip_vcnt
>= bip
->bip_max_vcnt
) {
141 printk(KERN_ERR
"%s: bip_vec full\n", __func__
);
145 iv
= bip
->bip_vec
+ bip
->bip_vcnt
;
148 bvec_gap_to_prev(bdev_get_queue(bio
->bi_bdev
),
149 &bip
->bip_vec
[bip
->bip_vcnt
- 1], offset
))
154 iv
->bv_offset
= offset
;
159 EXPORT_SYMBOL(bio_integrity_add_page
);
162 * bio_integrity_enabled - Check whether integrity can be passed
165 * Description: Determines whether bio_integrity_prep() can be called
166 * on this bio or not. bio data direction and target device must be
167 * set prior to calling. The functions honors the write_generate and
168 * read_verify flags in sysfs.
170 bool bio_integrity_enabled(struct bio
*bio
)
172 struct blk_integrity
*bi
= bdev_get_integrity(bio
->bi_bdev
);
177 /* Already protected? */
178 if (bio_integrity(bio
))
184 if (bio_data_dir(bio
) == READ
&& bi
->profile
->verify_fn
!= NULL
&&
185 (bi
->flags
& BLK_INTEGRITY_VERIFY
))
188 if (bio_data_dir(bio
) == WRITE
&& bi
->profile
->generate_fn
!= NULL
&&
189 (bi
->flags
& BLK_INTEGRITY_GENERATE
))
194 EXPORT_SYMBOL(bio_integrity_enabled
);
197 * bio_integrity_intervals - Return number of integrity intervals for a bio
198 * @bi: blk_integrity profile for device
199 * @sectors: Size of the bio in 512-byte sectors
201 * Description: The block layer calculates everything in 512 byte
202 * sectors but integrity metadata is done in terms of the data integrity
203 * interval size of the storage device. Convert the block layer sectors
204 * to the appropriate number of integrity intervals.
206 static inline unsigned int bio_integrity_intervals(struct blk_integrity
*bi
,
207 unsigned int sectors
)
209 return sectors
>> (bi
->interval_exp
- 9);
212 static inline unsigned int bio_integrity_bytes(struct blk_integrity
*bi
,
213 unsigned int sectors
)
215 return bio_integrity_intervals(bi
, sectors
) * bi
->tuple_size
;
219 * bio_integrity_process - Process integrity metadata for a bio
220 * @bio: bio to generate/verify integrity metadata for
221 * @proc_fn: Pointer to the relevant processing function
223 static int bio_integrity_process(struct bio
*bio
,
224 integrity_processing_fn
*proc_fn
)
226 struct blk_integrity
*bi
= bdev_get_integrity(bio
->bi_bdev
);
227 struct blk_integrity_iter iter
;
228 struct bvec_iter bviter
;
230 struct bio_integrity_payload
*bip
= bio_integrity(bio
);
231 unsigned int ret
= 0;
232 void *prot_buf
= page_address(bip
->bip_vec
->bv_page
) +
233 bip
->bip_vec
->bv_offset
;
235 iter
.disk_name
= bio
->bi_bdev
->bd_disk
->disk_name
;
236 iter
.interval
= 1 << bi
->interval_exp
;
237 iter
.seed
= bip_get_seed(bip
);
238 iter
.prot_buf
= prot_buf
;
240 bio_for_each_segment(bv
, bio
, bviter
) {
241 void *kaddr
= kmap_atomic(bv
.bv_page
);
243 iter
.data_buf
= kaddr
+ bv
.bv_offset
;
244 iter
.data_size
= bv
.bv_len
;
246 ret
= proc_fn(&iter
);
248 kunmap_atomic(kaddr
);
252 kunmap_atomic(kaddr
);
258 * bio_integrity_prep - Prepare bio for integrity I/O
259 * @bio: bio to prepare
261 * Description: Allocates a buffer for integrity metadata, maps the
262 * pages and attaches them to a bio. The bio must have data
263 * direction, target device and start sector set priot to calling. In
264 * the WRITE case, integrity metadata will be generated using the
265 * block device's integrity function. In the READ case, the buffer
266 * will be prepared for DMA and a suitable end_io handler set up.
268 int bio_integrity_prep(struct bio
*bio
)
270 struct bio_integrity_payload
*bip
;
271 struct blk_integrity
*bi
;
272 struct request_queue
*q
;
274 unsigned long start
, end
;
275 unsigned int len
, nr_pages
;
276 unsigned int bytes
, offset
, i
;
277 unsigned int intervals
;
279 bi
= bdev_get_integrity(bio
->bi_bdev
);
280 q
= bdev_get_queue(bio
->bi_bdev
);
282 BUG_ON(bio_integrity(bio
));
284 intervals
= bio_integrity_intervals(bi
, bio_sectors(bio
));
286 /* Allocate kernel buffer for protection data */
287 len
= intervals
* bi
->tuple_size
;
288 buf
= kmalloc(len
, GFP_NOIO
| q
->bounce_gfp
);
289 if (unlikely(buf
== NULL
)) {
290 printk(KERN_ERR
"could not allocate integrity buffer\n");
294 end
= (((unsigned long) buf
) + len
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
295 start
= ((unsigned long) buf
) >> PAGE_SHIFT
;
296 nr_pages
= end
- start
;
298 /* Allocate bio integrity payload and integrity vectors */
299 bip
= bio_integrity_alloc(bio
, GFP_NOIO
, nr_pages
);
301 printk(KERN_ERR
"could not allocate data integrity bioset\n");
306 bip
->bip_flags
|= BIP_BLOCK_INTEGRITY
;
307 bip
->bip_iter
.bi_size
= len
;
308 bip_set_seed(bip
, bio
->bi_iter
.bi_sector
);
310 if (bi
->flags
& BLK_INTEGRITY_IP_CHECKSUM
)
311 bip
->bip_flags
|= BIP_IP_CHECKSUM
;
314 offset
= offset_in_page(buf
);
315 for (i
= 0 ; i
< nr_pages
; i
++) {
317 bytes
= PAGE_SIZE
- offset
;
325 ret
= bio_integrity_add_page(bio
, virt_to_page(buf
),
339 /* Install custom I/O completion handler if read verify is enabled */
340 if (bio_data_dir(bio
) == READ
) {
341 bip
->bip_end_io
= bio
->bi_end_io
;
342 bio
->bi_end_io
= bio_integrity_endio
;
345 /* Auto-generate integrity metadata if this is a write */
346 if (bio_data_dir(bio
) == WRITE
)
347 bio_integrity_process(bio
, bi
->profile
->generate_fn
);
351 EXPORT_SYMBOL(bio_integrity_prep
);
354 * bio_integrity_verify_fn - Integrity I/O completion worker
355 * @work: Work struct stored in bio to be verified
357 * Description: This workqueue function is called to complete a READ
358 * request. The function verifies the transferred integrity metadata
359 * and then calls the original bio end_io function.
361 static void bio_integrity_verify_fn(struct work_struct
*work
)
363 struct bio_integrity_payload
*bip
=
364 container_of(work
, struct bio_integrity_payload
, bip_work
);
365 struct bio
*bio
= bip
->bip_bio
;
366 struct blk_integrity
*bi
= bdev_get_integrity(bio
->bi_bdev
);
368 bio
->bi_error
= bio_integrity_process(bio
, bi
->profile
->verify_fn
);
370 /* Restore original bio completion handler */
371 bio
->bi_end_io
= bip
->bip_end_io
;
376 * bio_integrity_endio - Integrity I/O completion function
377 * @bio: Protected bio
378 * @error: Pointer to errno
380 * Description: Completion for integrity I/O
382 * Normally I/O completion is done in interrupt context. However,
383 * verifying I/O integrity is a time-consuming task which must be run
384 * in process context. This function postpones completion
387 void bio_integrity_endio(struct bio
*bio
)
389 struct bio_integrity_payload
*bip
= bio_integrity(bio
);
391 BUG_ON(bip
->bip_bio
!= bio
);
393 /* In case of an I/O error there is no point in verifying the
394 * integrity metadata. Restore original bio end_io handler
398 bio
->bi_end_io
= bip
->bip_end_io
;
404 INIT_WORK(&bip
->bip_work
, bio_integrity_verify_fn
);
405 queue_work(kintegrityd_wq
, &bip
->bip_work
);
407 EXPORT_SYMBOL(bio_integrity_endio
);
410 * bio_integrity_advance - Advance integrity vector
411 * @bio: bio whose integrity vector to update
412 * @bytes_done: number of data bytes that have been completed
414 * Description: This function calculates how many integrity bytes the
415 * number of completed data bytes correspond to and advances the
416 * integrity vector accordingly.
418 void bio_integrity_advance(struct bio
*bio
, unsigned int bytes_done
)
420 struct bio_integrity_payload
*bip
= bio_integrity(bio
);
421 struct blk_integrity
*bi
= bdev_get_integrity(bio
->bi_bdev
);
422 unsigned bytes
= bio_integrity_bytes(bi
, bytes_done
>> 9);
424 bvec_iter_advance(bip
->bip_vec
, &bip
->bip_iter
, bytes
);
426 EXPORT_SYMBOL(bio_integrity_advance
);
429 * bio_integrity_trim - Trim integrity vector
430 * @bio: bio whose integrity vector to update
431 * @offset: offset to first data sector
432 * @sectors: number of data sectors
434 * Description: Used to trim the integrity vector in a cloned bio.
435 * The ivec will be advanced corresponding to 'offset' data sectors
436 * and the length will be truncated corresponding to 'len' data
439 void bio_integrity_trim(struct bio
*bio
, unsigned int offset
,
440 unsigned int sectors
)
442 struct bio_integrity_payload
*bip
= bio_integrity(bio
);
443 struct blk_integrity
*bi
= bdev_get_integrity(bio
->bi_bdev
);
445 bio_integrity_advance(bio
, offset
<< 9);
446 bip
->bip_iter
.bi_size
= bio_integrity_bytes(bi
, sectors
);
448 EXPORT_SYMBOL(bio_integrity_trim
);
451 * bio_integrity_clone - Callback for cloning bios with integrity metadata
453 * @bio_src: Original bio
454 * @gfp_mask: Memory allocation mask
456 * Description: Called to allocate a bip when cloning a bio
458 int bio_integrity_clone(struct bio
*bio
, struct bio
*bio_src
,
461 struct bio_integrity_payload
*bip_src
= bio_integrity(bio_src
);
462 struct bio_integrity_payload
*bip
;
464 BUG_ON(bip_src
== NULL
);
466 bip
= bio_integrity_alloc(bio
, gfp_mask
, bip_src
->bip_vcnt
);
470 memcpy(bip
->bip_vec
, bip_src
->bip_vec
,
471 bip_src
->bip_vcnt
* sizeof(struct bio_vec
));
473 bip
->bip_vcnt
= bip_src
->bip_vcnt
;
474 bip
->bip_iter
= bip_src
->bip_iter
;
478 EXPORT_SYMBOL(bio_integrity_clone
);
480 int bioset_integrity_create(struct bio_set
*bs
, int pool_size
)
482 if (bs
->bio_integrity_pool
)
485 bs
->bio_integrity_pool
= mempool_create_slab_pool(pool_size
, bip_slab
);
486 if (!bs
->bio_integrity_pool
)
489 bs
->bvec_integrity_pool
= biovec_create_pool(pool_size
);
490 if (!bs
->bvec_integrity_pool
) {
491 mempool_destroy(bs
->bio_integrity_pool
);
497 EXPORT_SYMBOL(bioset_integrity_create
);
499 void bioset_integrity_free(struct bio_set
*bs
)
501 if (bs
->bio_integrity_pool
)
502 mempool_destroy(bs
->bio_integrity_pool
);
504 if (bs
->bvec_integrity_pool
)
505 mempool_destroy(bs
->bvec_integrity_pool
);
507 EXPORT_SYMBOL(bioset_integrity_free
);
509 void __init
bio_integrity_init(void)
512 * kintegrityd won't block much but may burn a lot of CPU cycles.
513 * Make it highpri CPU intensive wq with max concurrency of 1.
515 kintegrityd_wq
= alloc_workqueue("kintegrityd", WQ_MEM_RECLAIM
|
516 WQ_HIGHPRI
| WQ_CPU_INTENSIVE
, 1);
518 panic("Failed to create kintegrityd\n");
520 bip_slab
= kmem_cache_create("bio_integrity_payload",
521 sizeof(struct bio_integrity_payload
) +
522 sizeof(struct bio_vec
) * BIP_INLINE_VECS
,
523 0, SLAB_HWCACHE_ALIGN
|SLAB_PANIC
, NULL
);