Line data Source code
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 __bvec_iter_bvec(bvec, iter) (&(bvec)[(iter).bi_idx])
65 :
66 : #define bvec_iter_page(bvec, iter) \
67 : (__bvec_iter_bvec((bvec), (iter))->bv_page)
68 :
69 : #define bvec_iter_len(bvec, iter) \
70 : min((iter).bi_size, \
71 : __bvec_iter_bvec((bvec), (iter))->bv_len - (iter).bi_bvec_done)
72 :
73 : #define bvec_iter_offset(bvec, iter) \
74 : (__bvec_iter_bvec((bvec), (iter))->bv_offset + (iter).bi_bvec_done)
75 :
76 : #define bvec_iter_bvec(bvec, iter) \
77 : ((struct bio_vec) { \
78 : .bv_page = bvec_iter_page((bvec), (iter)), \
79 : .bv_len = bvec_iter_len((bvec), (iter)), \
80 : .bv_offset = bvec_iter_offset((bvec), (iter)), \
81 : })
82 :
83 : #define bio_iter_iovec(bio, iter) \
84 : bvec_iter_bvec((bio)->bi_io_vec, (iter))
85 :
86 : #define bio_iter_page(bio, iter) \
87 : bvec_iter_page((bio)->bi_io_vec, (iter))
88 : #define bio_iter_len(bio, iter) \
89 : bvec_iter_len((bio)->bi_io_vec, (iter))
90 : #define bio_iter_offset(bio, iter) \
91 : bvec_iter_offset((bio)->bi_io_vec, (iter))
92 :
93 : #define bio_page(bio) bio_iter_page((bio), (bio)->bi_iter)
94 : #define bio_offset(bio) bio_iter_offset((bio), (bio)->bi_iter)
95 : #define bio_iovec(bio) bio_iter_iovec((bio), (bio)->bi_iter)
96 :
97 : #define bio_multiple_segments(bio) \
98 : ((bio)->bi_iter.bi_size != bio_iovec(bio).bv_len)
99 : #define bio_sectors(bio) ((bio)->bi_iter.bi_size >> 9)
100 : #define bio_end_sector(bio) ((bio)->bi_iter.bi_sector + bio_sectors((bio)))
101 :
102 : /*
103 : * Check whether this bio carries any data or not. A NULL bio is allowed.
104 : */
105 : static inline bool bio_has_data(struct bio *bio)
106 : {
107 : if (bio &&
108 : bio->bi_iter.bi_size &&
109 : !(bio->bi_rw & REQ_DISCARD))
110 : return true;
111 :
112 : return false;
113 : }
114 :
115 : static inline bool bio_is_rw(struct bio *bio)
116 : {
117 : if (!bio_has_data(bio))
118 : return false;
119 :
120 : if (bio->bi_rw & BIO_NO_ADVANCE_ITER_MASK)
121 : return false;
122 :
123 : return true;
124 : }
125 :
126 : static inline bool bio_mergeable(struct bio *bio)
127 : {
128 : if (bio->bi_rw & REQ_NOMERGE_FLAGS)
129 : return false;
130 :
131 : return true;
132 : }
133 :
134 : static inline unsigned int bio_cur_bytes(struct bio *bio)
135 : {
136 : if (bio_has_data(bio))
137 : return bio_iovec(bio).bv_len;
138 : else /* dataless requests such as discard */
139 : return bio->bi_iter.bi_size;
140 : }
141 :
142 : static inline void *bio_data(struct bio *bio)
143 : {
144 : if (bio_has_data(bio))
145 : return page_address(bio_page(bio)) + bio_offset(bio);
146 :
147 : return NULL;
148 : }
149 :
150 : /*
151 : * will die
152 : */
153 : #define bio_to_phys(bio) (page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
154 : #define bvec_to_phys(bv) (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
155 :
156 : /*
157 : * queues that have highmem support enabled may still need to revert to
158 : * PIO transfers occasionally and thus map high pages temporarily. For
159 : * permanent PIO fall back, user is probably better off disabling highmem
160 : * I/O completely on that queue (see ide-dma for example)
161 : */
162 : #define __bio_kmap_atomic(bio, iter) \
163 : (kmap_atomic(bio_iter_iovec((bio), (iter)).bv_page) + \
164 : bio_iter_iovec((bio), (iter)).bv_offset)
165 :
166 : #define __bio_kunmap_atomic(addr) kunmap_atomic(addr)
167 :
168 : /*
169 : * merge helpers etc
170 : */
171 :
172 : /* Default implementation of BIOVEC_PHYS_MERGEABLE */
173 : #define __BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
174 : ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
175 :
176 : /*
177 : * allow arch override, for eg virtualized architectures (put in asm/io.h)
178 : */
179 : #ifndef BIOVEC_PHYS_MERGEABLE
180 : #define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
181 : __BIOVEC_PHYS_MERGEABLE(vec1, vec2)
182 : #endif
183 :
184 : #define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
185 : (((addr1) | (mask)) == (((addr2) - 1) | (mask)))
186 : #define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
187 : __BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q)))
188 :
189 : /*
190 : * Check if adding a bio_vec after bprv with offset would create a gap in
191 : * the SG list. Most drivers don't care about this, but some do.
192 : */
193 : static inline bool bvec_gap_to_prev(struct bio_vec *bprv, unsigned int offset)
194 : {
195 : return offset || ((bprv->bv_offset + bprv->bv_len) & (PAGE_SIZE - 1));
196 : }
197 :
198 : #define bio_io_error(bio) bio_endio((bio), -EIO)
199 :
200 : /*
201 : * drivers should _never_ use the all version - the bio may have been split
202 : * before it got to the driver and the driver won't own all of it
203 : */
204 : #define bio_for_each_segment_all(bvl, bio, i) \
205 : for (i = 0, bvl = (bio)->bi_io_vec; i < (bio)->bi_vcnt; i++, bvl++)
206 :
207 : static inline void bvec_iter_advance(struct bio_vec *bv, struct bvec_iter *iter,
208 : unsigned bytes)
209 : {
210 : WARN_ONCE(bytes > iter->bi_size,
211 : "Attempted to advance past end of bvec iter\n");
212 :
213 : while (bytes) {
214 : unsigned len = min(bytes, bvec_iter_len(bv, *iter));
215 :
216 : bytes -= len;
217 : iter->bi_size -= len;
218 : iter->bi_bvec_done += len;
219 :
220 : if (iter->bi_bvec_done == __bvec_iter_bvec(bv, *iter)->bv_len) {
221 : iter->bi_bvec_done = 0;
222 : iter->bi_idx++;
223 : }
224 : }
225 : }
226 :
227 : #define for_each_bvec(bvl, bio_vec, iter, start) \
228 : for (iter = (start); \
229 : (iter).bi_size && \
230 : ((bvl = bvec_iter_bvec((bio_vec), (iter))), 1); \
231 : bvec_iter_advance((bio_vec), &(iter), (bvl).bv_len))
232 :
233 :
234 : static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter,
235 : unsigned bytes)
236 : {
237 : iter->bi_sector += bytes >> 9;
238 :
239 : if (bio->bi_rw & BIO_NO_ADVANCE_ITER_MASK)
240 : iter->bi_size -= bytes;
241 : else
242 : bvec_iter_advance(bio->bi_io_vec, iter, bytes);
243 : }
244 :
245 : #define __bio_for_each_segment(bvl, bio, iter, start) \
246 : for (iter = (start); \
247 : (iter).bi_size && \
248 : ((bvl = bio_iter_iovec((bio), (iter))), 1); \
249 : bio_advance_iter((bio), &(iter), (bvl).bv_len))
250 :
251 : #define bio_for_each_segment(bvl, bio, iter) \
252 : __bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter)
253 :
254 : #define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)
255 :
256 : static inline unsigned bio_segments(struct bio *bio)
257 : {
258 : unsigned segs = 0;
259 : struct bio_vec bv;
260 : struct bvec_iter iter;
261 :
262 : /*
263 : * We special case discard/write same, because they interpret bi_size
264 : * differently:
265 : */
266 :
267 : if (bio->bi_rw & REQ_DISCARD)
268 : return 1;
269 :
270 : if (bio->bi_rw & REQ_WRITE_SAME)
271 : return 1;
272 :
273 : bio_for_each_segment(bv, bio, iter)
274 : segs++;
275 :
276 : return segs;
277 : }
278 :
279 : /*
280 : * get a reference to a bio, so it won't disappear. the intended use is
281 : * something like:
282 : *
283 : * bio_get(bio);
284 : * submit_bio(rw, bio);
285 : * if (bio->bi_flags ...)
286 : * do_something
287 : * bio_put(bio);
288 : *
289 : * without the bio_get(), it could potentially complete I/O before submit_bio
290 : * returns. and then bio would be freed memory when if (bio->bi_flags ...)
291 : * runs
292 : */
293 : #define bio_get(bio) atomic_inc(&(bio)->bi_cnt)
294 :
295 : #if defined(CONFIG_BLK_DEV_INTEGRITY)
296 : /*
297 : * bio integrity payload
298 : */
299 : struct bio_integrity_payload {
300 : struct bio *bip_bio; /* parent bio */
301 :
302 : struct bvec_iter bip_iter;
303 :
304 : /* kill - should just use bip_vec */
305 : void *bip_buf; /* generated integrity data */
306 :
307 : bio_end_io_t *bip_end_io; /* saved I/O completion fn */
308 :
309 : unsigned short bip_slab; /* slab the bip came from */
310 : unsigned short bip_vcnt; /* # of integrity bio_vecs */
311 : unsigned short bip_max_vcnt; /* integrity bio_vec slots */
312 : unsigned bip_owns_buf:1; /* should free bip_buf */
313 :
314 : struct work_struct bip_work; /* I/O completion */
315 :
316 : struct bio_vec *bip_vec;
317 : struct bio_vec bip_inline_vecs[0];/* embedded bvec array */
318 : };
319 : #endif /* CONFIG_BLK_DEV_INTEGRITY */
320 :
321 : extern void bio_trim(struct bio *bio, int offset, int size);
322 : extern struct bio *bio_split(struct bio *bio, int sectors,
323 : gfp_t gfp, struct bio_set *bs);
324 :
325 : /**
326 : * bio_next_split - get next @sectors from a bio, splitting if necessary
327 : * @bio: bio to split
328 : * @sectors: number of sectors to split from the front of @bio
329 : * @gfp: gfp mask
330 : * @bs: bio set to allocate from
331 : *
332 : * Returns a bio representing the next @sectors of @bio - if the bio is smaller
333 : * than @sectors, returns the original bio unchanged.
334 : */
335 : static inline struct bio *bio_next_split(struct bio *bio, int sectors,
336 : gfp_t gfp, struct bio_set *bs)
337 : {
338 : if (sectors >= bio_sectors(bio))
339 : return bio;
340 :
341 : return bio_split(bio, sectors, gfp, bs);
342 : }
343 :
344 : extern struct bio_set *bioset_create(unsigned int, unsigned int);
345 : extern void bioset_free(struct bio_set *);
346 : extern mempool_t *biovec_create_pool(int pool_entries);
347 :
348 : extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
349 : extern void bio_put(struct bio *);
350 :
351 : extern void __bio_clone_fast(struct bio *, struct bio *);
352 : extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *);
353 : extern struct bio *bio_clone_bioset(struct bio *, gfp_t, struct bio_set *bs);
354 :
355 : extern struct bio_set *fs_bio_set;
356 : unsigned int bio_integrity_tag_size(struct bio *bio);
357 :
358 : static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
359 : {
360 : return bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set);
361 : }
362 :
363 : static inline struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask)
364 : {
365 : return bio_clone_bioset(bio, gfp_mask, fs_bio_set);
366 : }
367 :
368 : static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
369 : {
370 : return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
371 : }
372 :
373 : static inline struct bio *bio_clone_kmalloc(struct bio *bio, gfp_t gfp_mask)
374 : {
375 : return bio_clone_bioset(bio, gfp_mask, NULL);
376 :
377 : }
378 :
379 : extern void bio_endio(struct bio *, int);
380 : extern void bio_endio_nodec(struct bio *, int);
381 : struct request_queue;
382 : extern int bio_phys_segments(struct request_queue *, struct bio *);
383 :
384 : extern int submit_bio_wait(int rw, struct bio *bio);
385 : extern void bio_advance(struct bio *, unsigned);
386 :
387 : extern void bio_init(struct bio *);
388 : extern void bio_reset(struct bio *);
389 : void bio_chain(struct bio *, struct bio *);
390 :
391 : extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
392 : extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
393 : unsigned int, unsigned int);
394 : extern int bio_get_nr_vecs(struct block_device *);
395 : extern struct bio *bio_map_user(struct request_queue *, struct block_device *,
396 : unsigned long, unsigned int, int, gfp_t);
397 : struct sg_iovec;
398 : struct rq_map_data;
399 : extern struct bio *bio_map_user_iov(struct request_queue *,
400 : struct block_device *,
401 : const struct sg_iovec *, int, int, gfp_t);
402 : extern void bio_unmap_user(struct bio *);
403 : extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
404 : gfp_t);
405 : extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
406 : gfp_t, int);
407 : extern void bio_set_pages_dirty(struct bio *bio);
408 : extern void bio_check_pages_dirty(struct bio *bio);
409 :
410 : #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
411 : # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
412 : #endif
413 : #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
414 : extern void bio_flush_dcache_pages(struct bio *bi);
415 : #else
416 : static inline void bio_flush_dcache_pages(struct bio *bi)
417 : {
418 : }
419 : #endif
420 :
421 : extern void bio_copy_data(struct bio *dst, struct bio *src);
422 : extern int bio_alloc_pages(struct bio *bio, gfp_t gfp);
423 :
424 : extern struct bio *bio_copy_user(struct request_queue *, struct rq_map_data *,
425 : unsigned long, unsigned int, int, gfp_t);
426 : extern struct bio *bio_copy_user_iov(struct request_queue *,
427 : struct rq_map_data *,
428 : const struct sg_iovec *,
429 : int, int, gfp_t);
430 : extern int bio_uncopy_user(struct bio *);
431 : void zero_fill_bio(struct bio *bio);
432 : extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *);
433 : extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int);
434 : extern unsigned int bvec_nr_vecs(unsigned short idx);
435 :
436 : #ifdef CONFIG_BLK_CGROUP
437 : int bio_associate_current(struct bio *bio);
438 : void bio_disassociate_task(struct bio *bio);
439 : #else /* CONFIG_BLK_CGROUP */
440 : static inline int bio_associate_current(struct bio *bio) { return -ENOENT; }
441 : static inline void bio_disassociate_task(struct bio *bio) { }
442 : #endif /* CONFIG_BLK_CGROUP */
443 :
444 : #ifdef CONFIG_HIGHMEM
445 : /*
446 : * remember never ever reenable interrupts between a bvec_kmap_irq and
447 : * bvec_kunmap_irq!
448 : */
449 : static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
450 : {
451 : unsigned long addr;
452 :
453 : /*
454 : * might not be a highmem page, but the preempt/irq count
455 : * balancing is a lot nicer this way
456 : */
457 : local_irq_save(*flags);
458 : addr = (unsigned long) kmap_atomic(bvec->bv_page);
459 :
460 : BUG_ON(addr & ~PAGE_MASK);
461 :
462 : return (char *) addr + bvec->bv_offset;
463 : }
464 :
465 : static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
466 : {
467 : unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
468 :
469 : kunmap_atomic((void *) ptr);
470 : local_irq_restore(*flags);
471 : }
472 :
473 : #else
474 : static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
475 : {
476 : return page_address(bvec->bv_page) + bvec->bv_offset;
477 : }
478 :
479 : static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
480 : {
481 : *flags = 0;
482 : }
483 : #endif
484 :
485 : static inline char *__bio_kmap_irq(struct bio *bio, struct bvec_iter iter,
486 : unsigned long *flags)
487 : {
488 : return bvec_kmap_irq(&bio_iter_iovec(bio, iter), flags);
489 : }
490 : #define __bio_kunmap_irq(buf, flags) bvec_kunmap_irq(buf, flags)
491 :
492 : #define bio_kmap_irq(bio, flags) \
493 : __bio_kmap_irq((bio), (bio)->bi_iter, (flags))
494 : #define bio_kunmap_irq(buf,flags) __bio_kunmap_irq(buf, flags)
495 :
496 : /*
497 : * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
498 : *
499 : * A bio_list anchors a singly-linked list of bios chained through the bi_next
500 : * member of the bio. The bio_list also caches the last list member to allow
501 : * fast access to the tail.
502 : */
503 : struct bio_list {
504 : struct bio *head;
505 : struct bio *tail;
506 : };
507 :
508 : static inline int bio_list_empty(const struct bio_list *bl)
509 : {
510 44 : return bl->head == NULL;
511 : }
512 :
513 : static inline void bio_list_init(struct bio_list *bl)
514 : {
515 82 : bl->head = bl->tail = NULL;
516 : }
517 :
518 : #define BIO_EMPTY_LIST { NULL, NULL }
519 :
520 : #define bio_list_for_each(bio, bl) \
521 : for (bio = (bl)->head; bio; bio = bio->bi_next)
522 :
523 : static inline unsigned bio_list_size(const struct bio_list *bl)
524 : {
525 : unsigned sz = 0;
526 : struct bio *bio;
527 :
528 155 : bio_list_for_each(bio, bl)
529 155 : sz++;
530 :
531 : return sz;
532 : }
533 :
534 : static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
535 : {
536 193 : bio->bi_next = NULL;
537 :
538 193 : if (bl->tail)
539 113 : bl->tail->bi_next = bio;
540 : else
541 80 : bl->head = bio;
542 :
543 193 : bl->tail = bio;
544 : }
545 :
546 : static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
547 : {
548 : bio->bi_next = bl->head;
549 :
550 : bl->head = bio;
551 :
552 : if (!bl->tail)
553 : bl->tail = bio;
554 : }
555 :
556 : static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
557 : {
558 0 : if (!bl2->head)
559 : return;
560 :
561 0 : if (bl->tail)
562 0 : bl->tail->bi_next = bl2->head;
563 : else
564 0 : bl->head = bl2->head;
565 :
566 0 : bl->tail = bl2->tail;
567 : }
568 :
569 : static inline void bio_list_merge_head(struct bio_list *bl,
570 : struct bio_list *bl2)
571 : {
572 : if (!bl2->head)
573 : return;
574 :
575 : if (bl->head)
576 : bl2->tail->bi_next = bl->head;
577 : else
578 : bl->tail = bl2->tail;
579 :
580 : bl->head = bl2->head;
581 : }
582 :
583 : static inline struct bio *bio_list_peek(struct bio_list *bl)
584 : {
585 : return bl->head;
586 : }
587 :
588 : static inline struct bio *bio_list_pop(struct bio_list *bl)
589 : {
590 197 : struct bio *bio = bl->head;
591 :
592 197 : if (bio) {
593 155 : bl->head = bl->head->bi_next;
594 155 : if (!bl->head)
595 42 : bl->tail = NULL;
596 :
597 155 : bio->bi_next = NULL;
598 : }
599 :
600 : return bio;
601 : }
602 :
603 : static inline struct bio *bio_list_get(struct bio_list *bl)
604 : {
605 38 : struct bio *bio = bl->head;
606 :
607 38 : bl->head = bl->tail = NULL;
608 :
609 : return bio;
610 : }
611 :
612 : /*
613 : * bio_set is used to allow other portions of the IO system to
614 : * allocate their own private memory pools for bio and iovec structures.
615 : * These memory pools in turn all allocate from the bio_slab
616 : * and the bvec_slabs[].
617 : */
618 : #define BIO_POOL_SIZE 2
619 : #define BIOVEC_NR_POOLS 6
620 : #define BIOVEC_MAX_IDX (BIOVEC_NR_POOLS - 1)
621 :
622 : struct bio_set {
623 : struct kmem_cache *bio_slab;
624 : unsigned int front_pad;
625 :
626 : mempool_t *bio_pool;
627 : mempool_t *bvec_pool;
628 : #if defined(CONFIG_BLK_DEV_INTEGRITY)
629 : mempool_t *bio_integrity_pool;
630 : mempool_t *bvec_integrity_pool;
631 : #endif
632 :
633 : /*
634 : * Deadlock avoidance for stacking block drivers: see comments in
635 : * bio_alloc_bioset() for details
636 : */
637 : spinlock_t rescue_lock;
638 : struct bio_list rescue_list;
639 : struct work_struct rescue_work;
640 : struct workqueue_struct *rescue_workqueue;
641 : };
642 :
643 : struct biovec_slab {
644 : int nr_vecs;
645 : char *name;
646 : struct kmem_cache *slab;
647 : };
648 :
649 : /*
650 : * a small number of entries is fine, not going to be performance critical.
651 : * basically we just need to survive
652 : */
653 : #define BIO_SPLIT_ENTRIES 2
654 :
655 : #if defined(CONFIG_BLK_DEV_INTEGRITY)
656 :
657 : #define bip_for_each_vec(bvl, bip, iter) \
658 : for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
659 :
660 : #define bio_for_each_integrity_vec(_bvl, _bio, _iter) \
661 : for_each_bio(_bio) \
662 : bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
663 :
664 : #define bio_integrity(bio) (bio->bi_integrity != NULL)
665 :
666 : extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
667 : extern void bio_integrity_free(struct bio *);
668 : extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
669 : extern int bio_integrity_enabled(struct bio *bio);
670 : extern int bio_integrity_set_tag(struct bio *, void *, unsigned int);
671 : extern int bio_integrity_get_tag(struct bio *, void *, unsigned int);
672 : extern int bio_integrity_prep(struct bio *);
673 : extern void bio_integrity_endio(struct bio *, int);
674 : extern void bio_integrity_advance(struct bio *, unsigned int);
675 : extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
676 : extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t);
677 : extern int bioset_integrity_create(struct bio_set *, int);
678 : extern void bioset_integrity_free(struct bio_set *);
679 : extern void bio_integrity_init(void);
680 :
681 : #else /* CONFIG_BLK_DEV_INTEGRITY */
682 :
683 : static inline int bio_integrity(struct bio *bio)
684 : {
685 : return 0;
686 : }
687 :
688 : static inline int bio_integrity_enabled(struct bio *bio)
689 : {
690 : return 0;
691 : }
692 :
693 : static inline int bioset_integrity_create(struct bio_set *bs, int pool_size)
694 : {
695 : return 0;
696 : }
697 :
698 : static inline void bioset_integrity_free (struct bio_set *bs)
699 : {
700 : return;
701 : }
702 :
703 : static inline int bio_integrity_prep(struct bio *bio)
704 : {
705 : return 0;
706 : }
707 :
708 : static inline void bio_integrity_free(struct bio *bio)
709 : {
710 : return;
711 : }
712 :
713 : static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
714 : gfp_t gfp_mask)
715 : {
716 : return 0;
717 : }
718 :
719 : static inline void bio_integrity_advance(struct bio *bio,
720 : unsigned int bytes_done)
721 : {
722 : return;
723 : }
724 :
725 : static inline void bio_integrity_trim(struct bio *bio, unsigned int offset,
726 : unsigned int sectors)
727 : {
728 : return;
729 : }
730 :
731 : static inline void bio_integrity_init(void)
732 : {
733 : return;
734 : }
735 :
736 : #endif /* CONFIG_BLK_DEV_INTEGRITY */
737 :
738 : #endif /* CONFIG_BLOCK */
739 : #endif /* __LINUX_BIO_H */
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