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block: Fix a buffer overrun in bio_integrity_split()
[thirdparty/kernel/linux.git] / include / linux / bio.h
1 /*
2 * 2.5 block I/O model
3 *
4 * Copyright (C) 2001 Jens Axboe <axboe@suse.de>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 *
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public Licens
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-
19 */
20 #ifndef __LINUX_BIO_H
21 #define __LINUX_BIO_H
22
23 #include <linux/highmem.h>
24 #include <linux/mempool.h>
25 #include <linux/ioprio.h>
26 #include <linux/bug.h>
27
28 #ifdef CONFIG_BLOCK
29
30 #include <asm/io.h>
31
32 /* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */
33 #include <linux/blk_types.h>
34
35 #define BIO_DEBUG
36
37 #ifdef BIO_DEBUG
38 #define BIO_BUG_ON BUG_ON
39 #else
40 #define BIO_BUG_ON
41 #endif
42
43 #define BIO_MAX_PAGES 256
44 #define BIO_MAX_SIZE (BIO_MAX_PAGES << PAGE_CACHE_SHIFT)
45 #define BIO_MAX_SECTORS (BIO_MAX_SIZE >> 9)
46
47 /*
48 * upper 16 bits of bi_rw define the io priority of this bio
49 */
50 #define BIO_PRIO_SHIFT (8 * sizeof(unsigned long) - IOPRIO_BITS)
51 #define bio_prio(bio) ((bio)->bi_rw >> BIO_PRIO_SHIFT)
52 #define bio_prio_valid(bio) ioprio_valid(bio_prio(bio))
53
54 #define bio_set_prio(bio, prio) do { \
55 WARN_ON(prio >= (1 << IOPRIO_BITS)); \
56 (bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1); \
57 (bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT); \
58 } while (0)
59
60 /*
61 * various member access, note that bio_data should of course not be used
62 * on highmem page vectors
63 */
64 #define bio_iovec_idx(bio, idx) (&((bio)->bi_io_vec[(idx)]))
65 #define bio_iovec(bio) bio_iovec_idx((bio), (bio)->bi_idx)
66 #define bio_page(bio) bio_iovec((bio))->bv_page
67 #define bio_offset(bio) bio_iovec((bio))->bv_offset
68 #define bio_segments(bio) ((bio)->bi_vcnt - (bio)->bi_idx)
69 #define bio_sectors(bio) ((bio)->bi_size >> 9)
70
71 static inline unsigned int bio_cur_bytes(struct bio *bio)
72 {
73 if (bio->bi_vcnt)
74 return bio_iovec(bio)->bv_len;
75 else /* dataless requests such as discard */
76 return bio->bi_size;
77 }
78
79 static inline void *bio_data(struct bio *bio)
80 {
81 if (bio->bi_vcnt)
82 return page_address(bio_page(bio)) + bio_offset(bio);
83
84 return NULL;
85 }
86
87 static inline int bio_has_allocated_vec(struct bio *bio)
88 {
89 return bio->bi_io_vec && bio->bi_io_vec != bio->bi_inline_vecs;
90 }
91
92 /*
93 * will die
94 */
95 #define bio_to_phys(bio) (page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
96 #define bvec_to_phys(bv) (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
97
98 /*
99 * queues that have highmem support enabled may still need to revert to
100 * PIO transfers occasionally and thus map high pages temporarily. For
101 * permanent PIO fall back, user is probably better off disabling highmem
102 * I/O completely on that queue (see ide-dma for example)
103 */
104 #define __bio_kmap_atomic(bio, idx, kmtype) \
105 (kmap_atomic(bio_iovec_idx((bio), (idx))->bv_page) + \
106 bio_iovec_idx((bio), (idx))->bv_offset)
107
108 #define __bio_kunmap_atomic(addr, kmtype) kunmap_atomic(addr)
109
110 /*
111 * merge helpers etc
112 */
113
114 #define __BVEC_END(bio) bio_iovec_idx((bio), (bio)->bi_vcnt - 1)
115 #define __BVEC_START(bio) bio_iovec_idx((bio), (bio)->bi_idx)
116
117 /* Default implementation of BIOVEC_PHYS_MERGEABLE */
118 #define __BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
119 ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
120
121 /*
122 * allow arch override, for eg virtualized architectures (put in asm/io.h)
123 */
124 #ifndef BIOVEC_PHYS_MERGEABLE
125 #define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
126 __BIOVEC_PHYS_MERGEABLE(vec1, vec2)
127 #endif
128
129 #define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
130 (((addr1) | (mask)) == (((addr2) - 1) | (mask)))
131 #define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
132 __BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q)))
133 #define BIO_SEG_BOUNDARY(q, b1, b2) \
134 BIOVEC_SEG_BOUNDARY((q), __BVEC_END((b1)), __BVEC_START((b2)))
135
136 #define bio_io_error(bio) bio_endio((bio), -EIO)
137
138 /*
139 * drivers should not use the __ version unless they _really_ want to
140 * run through the entire bio and not just pending pieces
141 */
142 #define __bio_for_each_segment(bvl, bio, i, start_idx) \
143 for (bvl = bio_iovec_idx((bio), (start_idx)), i = (start_idx); \
144 i < (bio)->bi_vcnt; \
145 bvl++, i++)
146
147 #define bio_for_each_segment(bvl, bio, i) \
148 __bio_for_each_segment(bvl, bio, i, (bio)->bi_idx)
149
150 /*
151 * get a reference to a bio, so it won't disappear. the intended use is
152 * something like:
153 *
154 * bio_get(bio);
155 * submit_bio(rw, bio);
156 * if (bio->bi_flags ...)
157 * do_something
158 * bio_put(bio);
159 *
160 * without the bio_get(), it could potentially complete I/O before submit_bio
161 * returns. and then bio would be freed memory when if (bio->bi_flags ...)
162 * runs
163 */
164 #define bio_get(bio) atomic_inc(&(bio)->bi_cnt)
165
166 #if defined(CONFIG_BLK_DEV_INTEGRITY)
167 /*
168 * bio integrity payload
169 */
170 struct bio_integrity_payload {
171 struct bio *bip_bio; /* parent bio */
172
173 sector_t bip_sector; /* virtual start sector */
174
175 void *bip_buf; /* generated integrity data */
176 bio_end_io_t *bip_end_io; /* saved I/O completion fn */
177
178 unsigned int bip_size;
179
180 unsigned short bip_slab; /* slab the bip came from */
181 unsigned short bip_vcnt; /* # of integrity bio_vecs */
182 unsigned short bip_idx; /* current bip_vec index */
183
184 struct work_struct bip_work; /* I/O completion */
185
186 struct bio_vec *bip_vec;
187 struct bio_vec bip_inline_vecs[0];/* embedded bvec array */
188 };
189 #endif /* CONFIG_BLK_DEV_INTEGRITY */
190
191 /*
192 * A bio_pair is used when we need to split a bio.
193 * This can only happen for a bio that refers to just one
194 * page of data, and in the unusual situation when the
195 * page crosses a chunk/device boundary
196 *
197 * The address of the master bio is stored in bio1.bi_private
198 * The address of the pool the pair was allocated from is stored
199 * in bio2.bi_private
200 */
201 struct bio_pair {
202 struct bio bio1, bio2;
203 struct bio_vec bv1, bv2;
204 #if defined(CONFIG_BLK_DEV_INTEGRITY)
205 struct bio_integrity_payload bip1, bip2;
206 struct bio_vec iv1, iv2;
207 #endif
208 atomic_t cnt;
209 int error;
210 };
211 extern struct bio_pair *bio_split(struct bio *bi, int first_sectors);
212 extern void bio_pair_release(struct bio_pair *dbio);
213
214 extern struct bio_set *bioset_create(unsigned int, unsigned int);
215 extern void bioset_free(struct bio_set *);
216
217 extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
218 extern void bio_put(struct bio *);
219
220 extern void __bio_clone(struct bio *, struct bio *);
221 extern struct bio *bio_clone_bioset(struct bio *, gfp_t, struct bio_set *bs);
222
223 extern struct bio_set *fs_bio_set;
224
225 static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
226 {
227 return bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set);
228 }
229
230 static inline struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask)
231 {
232 return bio_clone_bioset(bio, gfp_mask, fs_bio_set);
233 }
234
235 static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
236 {
237 return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
238 }
239
240 static inline struct bio *bio_clone_kmalloc(struct bio *bio, gfp_t gfp_mask)
241 {
242 return bio_clone_bioset(bio, gfp_mask, NULL);
243
244 }
245
246 extern void bio_endio(struct bio *, int);
247 struct request_queue;
248 extern int bio_phys_segments(struct request_queue *, struct bio *);
249
250 extern void bio_init(struct bio *);
251 extern void bio_reset(struct bio *);
252
253 extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
254 extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
255 unsigned int, unsigned int);
256 extern int bio_get_nr_vecs(struct block_device *);
257 extern sector_t bio_sector_offset(struct bio *, unsigned short, unsigned int);
258 extern struct bio *bio_map_user(struct request_queue *, struct block_device *,
259 unsigned long, unsigned int, int, gfp_t);
260 struct sg_iovec;
261 struct rq_map_data;
262 extern struct bio *bio_map_user_iov(struct request_queue *,
263 struct block_device *,
264 struct sg_iovec *, int, int, gfp_t);
265 extern void bio_unmap_user(struct bio *);
266 extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
267 gfp_t);
268 extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
269 gfp_t, int);
270 extern void bio_set_pages_dirty(struct bio *bio);
271 extern void bio_check_pages_dirty(struct bio *bio);
272
273 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
274 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
275 #endif
276 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
277 extern void bio_flush_dcache_pages(struct bio *bi);
278 #else
279 static inline void bio_flush_dcache_pages(struct bio *bi)
280 {
281 }
282 #endif
283
284 extern struct bio *bio_copy_user(struct request_queue *, struct rq_map_data *,
285 unsigned long, unsigned int, int, gfp_t);
286 extern struct bio *bio_copy_user_iov(struct request_queue *,
287 struct rq_map_data *, struct sg_iovec *,
288 int, int, gfp_t);
289 extern int bio_uncopy_user(struct bio *);
290 void zero_fill_bio(struct bio *bio);
291 extern struct bio_vec *bvec_alloc_bs(gfp_t, int, unsigned long *, struct bio_set *);
292 extern void bvec_free_bs(struct bio_set *, struct bio_vec *, unsigned int);
293 extern unsigned int bvec_nr_vecs(unsigned short idx);
294
295 #ifdef CONFIG_BLK_CGROUP
296 int bio_associate_current(struct bio *bio);
297 void bio_disassociate_task(struct bio *bio);
298 #else /* CONFIG_BLK_CGROUP */
299 static inline int bio_associate_current(struct bio *bio) { return -ENOENT; }
300 static inline void bio_disassociate_task(struct bio *bio) { }
301 #endif /* CONFIG_BLK_CGROUP */
302
303 #ifdef CONFIG_HIGHMEM
304 /*
305 * remember never ever reenable interrupts between a bvec_kmap_irq and
306 * bvec_kunmap_irq!
307 */
308 static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
309 {
310 unsigned long addr;
311
312 /*
313 * might not be a highmem page, but the preempt/irq count
314 * balancing is a lot nicer this way
315 */
316 local_irq_save(*flags);
317 addr = (unsigned long) kmap_atomic(bvec->bv_page);
318
319 BUG_ON(addr & ~PAGE_MASK);
320
321 return (char *) addr + bvec->bv_offset;
322 }
323
324 static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
325 {
326 unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
327
328 kunmap_atomic((void *) ptr);
329 local_irq_restore(*flags);
330 }
331
332 #else
333 static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
334 {
335 return page_address(bvec->bv_page) + bvec->bv_offset;
336 }
337
338 static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
339 {
340 *flags = 0;
341 }
342 #endif
343
344 static inline char *__bio_kmap_irq(struct bio *bio, unsigned short idx,
345 unsigned long *flags)
346 {
347 return bvec_kmap_irq(bio_iovec_idx(bio, idx), flags);
348 }
349 #define __bio_kunmap_irq(buf, flags) bvec_kunmap_irq(buf, flags)
350
351 #define bio_kmap_irq(bio, flags) \
352 __bio_kmap_irq((bio), (bio)->bi_idx, (flags))
353 #define bio_kunmap_irq(buf,flags) __bio_kunmap_irq(buf, flags)
354
355 /*
356 * Check whether this bio carries any data or not. A NULL bio is allowed.
357 */
358 static inline bool bio_has_data(struct bio *bio)
359 {
360 if (bio && bio->bi_vcnt)
361 return true;
362
363 return false;
364 }
365
366 static inline bool bio_is_rw(struct bio *bio)
367 {
368 if (!bio_has_data(bio))
369 return false;
370
371 if (bio->bi_rw & REQ_WRITE_SAME)
372 return false;
373
374 return true;
375 }
376
377 static inline bool bio_mergeable(struct bio *bio)
378 {
379 if (bio->bi_rw & REQ_NOMERGE_FLAGS)
380 return false;
381
382 return true;
383 }
384
385 /*
386 * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
387 *
388 * A bio_list anchors a singly-linked list of bios chained through the bi_next
389 * member of the bio. The bio_list also caches the last list member to allow
390 * fast access to the tail.
391 */
392 struct bio_list {
393 struct bio *head;
394 struct bio *tail;
395 };
396
397 static inline int bio_list_empty(const struct bio_list *bl)
398 {
399 return bl->head == NULL;
400 }
401
402 static inline void bio_list_init(struct bio_list *bl)
403 {
404 bl->head = bl->tail = NULL;
405 }
406
407 #define bio_list_for_each(bio, bl) \
408 for (bio = (bl)->head; bio; bio = bio->bi_next)
409
410 static inline unsigned bio_list_size(const struct bio_list *bl)
411 {
412 unsigned sz = 0;
413 struct bio *bio;
414
415 bio_list_for_each(bio, bl)
416 sz++;
417
418 return sz;
419 }
420
421 static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
422 {
423 bio->bi_next = NULL;
424
425 if (bl->tail)
426 bl->tail->bi_next = bio;
427 else
428 bl->head = bio;
429
430 bl->tail = bio;
431 }
432
433 static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
434 {
435 bio->bi_next = bl->head;
436
437 bl->head = bio;
438
439 if (!bl->tail)
440 bl->tail = bio;
441 }
442
443 static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
444 {
445 if (!bl2->head)
446 return;
447
448 if (bl->tail)
449 bl->tail->bi_next = bl2->head;
450 else
451 bl->head = bl2->head;
452
453 bl->tail = bl2->tail;
454 }
455
456 static inline void bio_list_merge_head(struct bio_list *bl,
457 struct bio_list *bl2)
458 {
459 if (!bl2->head)
460 return;
461
462 if (bl->head)
463 bl2->tail->bi_next = bl->head;
464 else
465 bl->tail = bl2->tail;
466
467 bl->head = bl2->head;
468 }
469
470 static inline struct bio *bio_list_peek(struct bio_list *bl)
471 {
472 return bl->head;
473 }
474
475 static inline struct bio *bio_list_pop(struct bio_list *bl)
476 {
477 struct bio *bio = bl->head;
478
479 if (bio) {
480 bl->head = bl->head->bi_next;
481 if (!bl->head)
482 bl->tail = NULL;
483
484 bio->bi_next = NULL;
485 }
486
487 return bio;
488 }
489
490 static inline struct bio *bio_list_get(struct bio_list *bl)
491 {
492 struct bio *bio = bl->head;
493
494 bl->head = bl->tail = NULL;
495
496 return bio;
497 }
498
499 /*
500 * bio_set is used to allow other portions of the IO system to
501 * allocate their own private memory pools for bio and iovec structures.
502 * These memory pools in turn all allocate from the bio_slab
503 * and the bvec_slabs[].
504 */
505 #define BIO_POOL_SIZE 2
506 #define BIOVEC_NR_POOLS 6
507 #define BIOVEC_MAX_IDX (BIOVEC_NR_POOLS - 1)
508
509 struct bio_set {
510 struct kmem_cache *bio_slab;
511 unsigned int front_pad;
512
513 mempool_t *bio_pool;
514 #if defined(CONFIG_BLK_DEV_INTEGRITY)
515 mempool_t *bio_integrity_pool;
516 #endif
517 mempool_t *bvec_pool;
518
519 /*
520 * Deadlock avoidance for stacking block drivers: see comments in
521 * bio_alloc_bioset() for details
522 */
523 spinlock_t rescue_lock;
524 struct bio_list rescue_list;
525 struct work_struct rescue_work;
526 struct workqueue_struct *rescue_workqueue;
527 };
528
529 struct biovec_slab {
530 int nr_vecs;
531 char *name;
532 struct kmem_cache *slab;
533 };
534
535 /*
536 * a small number of entries is fine, not going to be performance critical.
537 * basically we just need to survive
538 */
539 #define BIO_SPLIT_ENTRIES 2
540
541 #if defined(CONFIG_BLK_DEV_INTEGRITY)
542
543 #define bip_vec_idx(bip, idx) (&(bip->bip_vec[(idx)]))
544 #define bip_vec(bip) bip_vec_idx(bip, 0)
545
546 #define __bip_for_each_vec(bvl, bip, i, start_idx) \
547 for (bvl = bip_vec_idx((bip), (start_idx)), i = (start_idx); \
548 i < (bip)->bip_vcnt; \
549 bvl++, i++)
550
551 #define bip_for_each_vec(bvl, bip, i) \
552 __bip_for_each_vec(bvl, bip, i, (bip)->bip_idx)
553
554 #define bio_for_each_integrity_vec(_bvl, _bio, _iter) \
555 for_each_bio(_bio) \
556 bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
557
558 #define bio_integrity(bio) (bio->bi_integrity != NULL)
559
560 extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
561 extern void bio_integrity_free(struct bio *);
562 extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
563 extern int bio_integrity_enabled(struct bio *bio);
564 extern int bio_integrity_set_tag(struct bio *, void *, unsigned int);
565 extern int bio_integrity_get_tag(struct bio *, void *, unsigned int);
566 extern int bio_integrity_prep(struct bio *);
567 extern void bio_integrity_endio(struct bio *, int);
568 extern void bio_integrity_advance(struct bio *, unsigned int);
569 extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
570 extern void bio_integrity_split(struct bio *, struct bio_pair *, int);
571 extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t);
572 extern int bioset_integrity_create(struct bio_set *, int);
573 extern void bioset_integrity_free(struct bio_set *);
574 extern void bio_integrity_init(void);
575
576 #else /* CONFIG_BLK_DEV_INTEGRITY */
577
578 static inline int bio_integrity(struct bio *bio)
579 {
580 return 0;
581 }
582
583 static inline int bio_integrity_enabled(struct bio *bio)
584 {
585 return 0;
586 }
587
588 static inline int bioset_integrity_create(struct bio_set *bs, int pool_size)
589 {
590 return 0;
591 }
592
593 static inline void bioset_integrity_free (struct bio_set *bs)
594 {
595 return;
596 }
597
598 static inline int bio_integrity_prep(struct bio *bio)
599 {
600 return 0;
601 }
602
603 static inline void bio_integrity_free(struct bio *bio)
604 {
605 return;
606 }
607
608 static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
609 gfp_t gfp_mask)
610 {
611 return 0;
612 }
613
614 static inline void bio_integrity_split(struct bio *bio, struct bio_pair *bp,
615 int sectors)
616 {
617 return;
618 }
619
620 static inline void bio_integrity_advance(struct bio *bio,
621 unsigned int bytes_done)
622 {
623 return;
624 }
625
626 static inline void bio_integrity_trim(struct bio *bio, unsigned int offset,
627 unsigned int sectors)
628 {
629 return;
630 }
631
632 static inline void bio_integrity_init(void)
633 {
634 return;
635 }
636
637 #endif /* CONFIG_BLK_DEV_INTEGRITY */
638
639 #endif /* CONFIG_BLOCK */
640 #endif /* __LINUX_BIO_H */