1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright (C) 2001 Jens Axboe <axboe@suse.de>
4 */
5#ifndef __LINUX_BIO_H
6#define __LINUX_BIO_H
7
8#include <linux/mempool.h>
9/* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */
10#include <linux/blk_types.h>
11#include <linux/uio.h>
12
13#define BIO_MAX_VECS 256U
14
15struct queue_limits;
16
17static inline unsigned int bio_max_segs(unsigned int nr_segs)
18{
19 return min(nr_segs, BIO_MAX_VECS);
20}
21
22#define bio_prio(bio) (bio)->bi_ioprio
23#define bio_set_prio(bio, prio) ((bio)->bi_ioprio = prio)
24
25#define bio_iter_iovec(bio, iter) \
26 bvec_iter_bvec((bio)->bi_io_vec, (iter))
27
28#define bio_iter_page(bio, iter) \
29 bvec_iter_page((bio)->bi_io_vec, (iter))
30#define bio_iter_len(bio, iter) \
31 bvec_iter_len((bio)->bi_io_vec, (iter))
32#define bio_iter_offset(bio, iter) \
33 bvec_iter_offset((bio)->bi_io_vec, (iter))
34
35#define bio_page(bio) bio_iter_page((bio), (bio)->bi_iter)
36#define bio_offset(bio) bio_iter_offset((bio), (bio)->bi_iter)
37#define bio_iovec(bio) bio_iter_iovec((bio), (bio)->bi_iter)
38
39#define bvec_iter_sectors(iter) ((iter).bi_size >> 9)
40#define bvec_iter_end_sector(iter) ((iter).bi_sector + bvec_iter_sectors((iter)))
41
42#define bio_sectors(bio) bvec_iter_sectors((bio)->bi_iter)
43#define bio_end_sector(bio) bvec_iter_end_sector((bio)->bi_iter)
44
45/*
46 * Return the data direction, READ or WRITE.
47 */
48#define bio_data_dir(bio) \
49 (op_is_write(bio_op(bio)) ? WRITE : READ)
50
51/*
52 * Check whether this bio carries any data or not. A NULL bio is allowed.
53 */
54static inline bool bio_has_data(struct bio *bio)
55{
56 if (bio &&
57 bio->bi_iter.bi_size &&
58 bio_op(bio) != REQ_OP_DISCARD &&
59 bio_op(bio) != REQ_OP_SECURE_ERASE &&
60 bio_op(bio) != REQ_OP_WRITE_ZEROES)
61 return true;
62
63 return false;
64}
65
66static inline bool bio_no_advance_iter(const struct bio *bio)
67{
68 return bio_op(bio) == REQ_OP_DISCARD ||
69 bio_op(bio) == REQ_OP_SECURE_ERASE ||
70 bio_op(bio) == REQ_OP_WRITE_ZEROES;
71}
72
73static inline void *bio_data(struct bio *bio)
74{
75 if (bio_has_data(bio))
76 return page_address(bio_page(bio)) + bio_offset(bio);
77
78 return NULL;
79}
80
81static inline bool bio_next_segment(const struct bio *bio,
82 struct bvec_iter_all *iter)
83{
84 if (iter->idx >= bio->bi_vcnt)
85 return false;
86
87 bvec_advance(bvec: &bio->bi_io_vec[iter->idx], iter_all: iter);
88 return true;
89}
90
91/*
92 * drivers should _never_ use the all version - the bio may have been split
93 * before it got to the driver and the driver won't own all of it
94 */
95#define bio_for_each_segment_all(bvl, bio, iter) \
96 for (bvl = bvec_init_iter_all(&iter); bio_next_segment((bio), &iter); )
97
98static inline void bio_advance_iter(const struct bio *bio,
99 struct bvec_iter *iter, unsigned int bytes)
100{
101 iter->bi_sector += bytes >> 9;
102
103 if (bio_no_advance_iter(bio))
104 iter->bi_size -= bytes;
105 else
106 bvec_iter_advance(bv: bio->bi_io_vec, iter, bytes);
107 /* TODO: It is reasonable to complete bio with error here. */
108}
109
110/* @bytes should be less or equal to bvec[i->bi_idx].bv_len */
111static inline void bio_advance_iter_single(const struct bio *bio,
112 struct bvec_iter *iter,
113 unsigned int bytes)
114{
115 iter->bi_sector += bytes >> 9;
116
117 if (bio_no_advance_iter(bio))
118 iter->bi_size -= bytes;
119 else
120 bvec_iter_advance_single(bv: bio->bi_io_vec, iter, bytes);
121}
122
123void __bio_advance(struct bio *, unsigned bytes);
124
125/**
126 * bio_advance - increment/complete a bio by some number of bytes
127 * @bio: bio to advance
128 * @nbytes: number of bytes to complete
129 *
130 * This updates bi_sector, bi_size and bi_idx; if the number of bytes to
131 * complete doesn't align with a bvec boundary, then bv_len and bv_offset will
132 * be updated on the last bvec as well.
133 *
134 * @bio will then represent the remaining, uncompleted portion of the io.
135 */
136static inline void bio_advance(struct bio *bio, unsigned int nbytes)
137{
138 if (nbytes == bio->bi_iter.bi_size) {
139 bio->bi_iter.bi_size = 0;
140 return;
141 }
142 __bio_advance(bio, bytes: nbytes);
143}
144
145#define __bio_for_each_segment(bvl, bio, iter, start) \
146 for (iter = (start); \
147 (iter).bi_size && \
148 ((bvl = bio_iter_iovec((bio), (iter))), 1); \
149 bio_advance_iter_single((bio), &(iter), (bvl).bv_len))
150
151#define bio_for_each_segment(bvl, bio, iter) \
152 __bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter)
153
154#define __bio_for_each_bvec(bvl, bio, iter, start) \
155 for (iter = (start); \
156 (iter).bi_size && \
157 ((bvl = mp_bvec_iter_bvec((bio)->bi_io_vec, (iter))), 1); \
158 bio_advance_iter_single((bio), &(iter), (bvl).bv_len))
159
160/* iterate over multi-page bvec */
161#define bio_for_each_bvec(bvl, bio, iter) \
162 __bio_for_each_bvec(bvl, bio, iter, (bio)->bi_iter)
163
164/*
165 * Iterate over all multi-page bvecs. Drivers shouldn't use this version for the
166 * same reasons as bio_for_each_segment_all().
167 */
168#define bio_for_each_bvec_all(bvl, bio, i) \
169 for (i = 0, bvl = bio_first_bvec_all(bio); \
170 i < (bio)->bi_vcnt; i++, bvl++)
171
172#define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)
173
174static inline unsigned bio_segments(struct bio *bio)
175{
176 unsigned segs = 0;
177 struct bio_vec bv;
178 struct bvec_iter iter;
179
180 /*
181 * We special case discard/write same/write zeroes, because they
182 * interpret bi_size differently:
183 */
184
185 switch (bio_op(bio)) {
186 case REQ_OP_DISCARD:
187 case REQ_OP_SECURE_ERASE:
188 case REQ_OP_WRITE_ZEROES:
189 return 0;
190 default:
191 break;
192 }
193
194 bio_for_each_segment(bv, bio, iter)
195 segs++;
196
197 return segs;
198}
199
200/*
201 * get a reference to a bio, so it won't disappear. the intended use is
202 * something like:
203 *
204 * bio_get(bio);
205 * submit_bio(rw, bio);
206 * if (bio->bi_flags ...)
207 * do_something
208 * bio_put(bio);
209 *
210 * without the bio_get(), it could potentially complete I/O before submit_bio
211 * returns. and then bio would be freed memory when if (bio->bi_flags ...)
212 * runs
213 */
214static inline void bio_get(struct bio *bio)
215{
216 bio->bi_flags |= (1 << BIO_REFFED);
217 smp_mb__before_atomic();
218 atomic_inc(v: &bio->__bi_cnt);
219}
220
221static inline void bio_cnt_set(struct bio *bio, unsigned int count)
222{
223 if (count != 1) {
224 bio->bi_flags |= (1 << BIO_REFFED);
225 smp_mb();
226 }
227 atomic_set(v: &bio->__bi_cnt, i: count);
228}
229
230static inline bool bio_flagged(struct bio *bio, unsigned int bit)
231{
232 return bio->bi_flags & (1U << bit);
233}
234
235static inline void bio_set_flag(struct bio *bio, unsigned int bit)
236{
237 bio->bi_flags |= (1U << bit);
238}
239
240static inline void bio_clear_flag(struct bio *bio, unsigned int bit)
241{
242 bio->bi_flags &= ~(1U << bit);
243}
244
245static inline struct bio_vec *bio_first_bvec_all(struct bio *bio)
246{
247 WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
248 return bio->bi_io_vec;
249}
250
251static inline struct page *bio_first_page_all(struct bio *bio)
252{
253 return bio_first_bvec_all(bio)->bv_page;
254}
255
256static inline struct folio *bio_first_folio_all(struct bio *bio)
257{
258 return page_folio(bio_first_page_all(bio));
259}
260
261static inline struct bio_vec *bio_last_bvec_all(struct bio *bio)
262{
263 WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
264 return &bio->bi_io_vec[bio->bi_vcnt - 1];
265}
266
267/**
268 * struct folio_iter - State for iterating all folios in a bio.
269 * @folio: The current folio we're iterating. NULL after the last folio.
270 * @offset: The byte offset within the current folio.
271 * @length: The number of bytes in this iteration (will not cross folio
272 * boundary).
273 */
274struct folio_iter {
275 struct folio *folio;
276 size_t offset;
277 size_t length;
278 /* private: for use by the iterator */
279 struct folio *_next;
280 size_t _seg_count;
281 int _i;
282};
283
284static inline void bio_first_folio(struct folio_iter *fi, struct bio *bio,
285 int i)
286{
287 struct bio_vec *bvec = bio_first_bvec_all(bio) + i;
288
289 fi->folio = page_folio(bvec->bv_page);
290 fi->offset = bvec->bv_offset +
291 PAGE_SIZE * (bvec->bv_page - &fi->folio->page);
292 fi->_seg_count = bvec->bv_len;
293 fi->length = min(folio_size(fi->folio) - fi->offset, fi->_seg_count);
294 fi->_next = folio_next(folio: fi->folio);
295 fi->_i = i;
296}
297
298static inline void bio_next_folio(struct folio_iter *fi, struct bio *bio)
299{
300 fi->_seg_count -= fi->length;
301 if (fi->_seg_count) {
302 fi->folio = fi->_next;
303 fi->offset = 0;
304 fi->length = min(folio_size(fi->folio), fi->_seg_count);
305 fi->_next = folio_next(folio: fi->folio);
306 } else if (fi->_i + 1 < bio->bi_vcnt) {
307 bio_first_folio(fi, bio, i: fi->_i + 1);
308 } else {
309 fi->folio = NULL;
310 }
311}
312
313/**
314 * bio_for_each_folio_all - Iterate over each folio in a bio.
315 * @fi: struct folio_iter which is updated for each folio.
316 * @bio: struct bio to iterate over.
317 */
318#define bio_for_each_folio_all(fi, bio) \
319 for (bio_first_folio(&fi, bio, 0); fi.folio; bio_next_folio(&fi, bio))
320
321enum bip_flags {
322 BIP_BLOCK_INTEGRITY = 1 << 0, /* block layer owns integrity data */
323 BIP_MAPPED_INTEGRITY = 1 << 1, /* ref tag has been remapped */
324 BIP_CTRL_NOCHECK = 1 << 2, /* disable HBA integrity checking */
325 BIP_DISK_NOCHECK = 1 << 3, /* disable disk integrity checking */
326 BIP_IP_CHECKSUM = 1 << 4, /* IP checksum */
327};
328
329/*
330 * bio integrity payload
331 */
332struct bio_integrity_payload {
333 struct bio *bip_bio; /* parent bio */
334
335 struct bvec_iter bip_iter;
336
337 unsigned short bip_vcnt; /* # of integrity bio_vecs */
338 unsigned short bip_max_vcnt; /* integrity bio_vec slots */
339 unsigned short bip_flags; /* control flags */
340
341 struct bvec_iter bio_iter; /* for rewinding parent bio */
342
343 struct work_struct bip_work; /* I/O completion */
344
345 struct bio_vec *bip_vec;
346 struct bio_vec bip_inline_vecs[];/* embedded bvec array */
347};
348
349#if defined(CONFIG_BLK_DEV_INTEGRITY)
350
351static inline struct bio_integrity_payload *bio_integrity(struct bio *bio)
352{
353 if (bio->bi_opf & REQ_INTEGRITY)
354 return bio->bi_integrity;
355
356 return NULL;
357}
358
359static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
360{
361 struct bio_integrity_payload *bip = bio_integrity(bio);
362
363 if (bip)
364 return bip->bip_flags & flag;
365
366 return false;
367}
368
369static inline sector_t bip_get_seed(struct bio_integrity_payload *bip)
370{
371 return bip->bip_iter.bi_sector;
372}
373
374static inline void bip_set_seed(struct bio_integrity_payload *bip,
375 sector_t seed)
376{
377 bip->bip_iter.bi_sector = seed;
378}
379
380#endif /* CONFIG_BLK_DEV_INTEGRITY */
381
382void bio_trim(struct bio *bio, sector_t offset, sector_t size);
383extern struct bio *bio_split(struct bio *bio, int sectors,
384 gfp_t gfp, struct bio_set *bs);
385struct bio *bio_split_rw(struct bio *bio, const struct queue_limits *lim,
386 unsigned *segs, struct bio_set *bs, unsigned max_bytes);
387
388/**
389 * bio_next_split - get next @sectors from a bio, splitting if necessary
390 * @bio: bio to split
391 * @sectors: number of sectors to split from the front of @bio
392 * @gfp: gfp mask
393 * @bs: bio set to allocate from
394 *
395 * Return: a bio representing the next @sectors of @bio - if the bio is smaller
396 * than @sectors, returns the original bio unchanged.
397 */
398static inline struct bio *bio_next_split(struct bio *bio, int sectors,
399 gfp_t gfp, struct bio_set *bs)
400{
401 if (sectors >= bio_sectors(bio))
402 return bio;
403
404 return bio_split(bio, sectors, gfp, bs);
405}
406
407enum {
408 BIOSET_NEED_BVECS = BIT(0),
409 BIOSET_NEED_RESCUER = BIT(1),
410 BIOSET_PERCPU_CACHE = BIT(2),
411};
412extern int bioset_init(struct bio_set *, unsigned int, unsigned int, int flags);
413extern void bioset_exit(struct bio_set *);
414extern int biovec_init_pool(mempool_t *pool, int pool_entries);
415
416struct bio *bio_alloc_bioset(struct block_device *bdev, unsigned short nr_vecs,
417 blk_opf_t opf, gfp_t gfp_mask,
418 struct bio_set *bs);
419struct bio *bio_kmalloc(unsigned short nr_vecs, gfp_t gfp_mask);
420extern void bio_put(struct bio *);
421
422struct bio *bio_alloc_clone(struct block_device *bdev, struct bio *bio_src,
423 gfp_t gfp, struct bio_set *bs);
424int bio_init_clone(struct block_device *bdev, struct bio *bio,
425 struct bio *bio_src, gfp_t gfp);
426
427extern struct bio_set fs_bio_set;
428
429static inline struct bio *bio_alloc(struct block_device *bdev,
430 unsigned short nr_vecs, blk_opf_t opf, gfp_t gfp_mask)
431{
432 return bio_alloc_bioset(bdev, nr_vecs, opf, gfp_mask, bs: &fs_bio_set);
433}
434
435void submit_bio(struct bio *bio);
436
437extern void bio_endio(struct bio *);
438
439static inline void bio_io_error(struct bio *bio)
440{
441 bio->bi_status = BLK_STS_IOERR;
442 bio_endio(bio);
443}
444
445static inline void bio_wouldblock_error(struct bio *bio)
446{
447 bio_set_flag(bio, bit: BIO_QUIET);
448 bio->bi_status = BLK_STS_AGAIN;
449 bio_endio(bio);
450}
451
452/*
453 * Calculate number of bvec segments that should be allocated to fit data
454 * pointed by @iter. If @iter is backed by bvec it's going to be reused
455 * instead of allocating a new one.
456 */
457static inline int bio_iov_vecs_to_alloc(struct iov_iter *iter, int max_segs)
458{
459 if (iov_iter_is_bvec(i: iter))
460 return 0;
461 return iov_iter_npages(i: iter, maxpages: max_segs);
462}
463
464struct request_queue;
465
466extern int submit_bio_wait(struct bio *bio);
467void bio_init(struct bio *bio, struct block_device *bdev, struct bio_vec *table,
468 unsigned short max_vecs, blk_opf_t opf);
469extern void bio_uninit(struct bio *);
470void bio_reset(struct bio *bio, struct block_device *bdev, blk_opf_t opf);
471void bio_chain(struct bio *, struct bio *);
472
473int __must_check bio_add_page(struct bio *bio, struct page *page, unsigned len,
474 unsigned off);
475bool __must_check bio_add_folio(struct bio *bio, struct folio *folio,
476 size_t len, size_t off);
477extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
478 unsigned int, unsigned int);
479int bio_add_zone_append_page(struct bio *bio, struct page *page,
480 unsigned int len, unsigned int offset);
481void __bio_add_page(struct bio *bio, struct page *page,
482 unsigned int len, unsigned int off);
483void bio_add_folio_nofail(struct bio *bio, struct folio *folio, size_t len,
484 size_t off);
485int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter);
486void bio_iov_bvec_set(struct bio *bio, struct iov_iter *iter);
487void __bio_release_pages(struct bio *bio, bool mark_dirty);
488extern void bio_set_pages_dirty(struct bio *bio);
489extern void bio_check_pages_dirty(struct bio *bio);
490
491extern void bio_copy_data_iter(struct bio *dst, struct bvec_iter *dst_iter,
492 struct bio *src, struct bvec_iter *src_iter);
493extern void bio_copy_data(struct bio *dst, struct bio *src);
494extern void bio_free_pages(struct bio *bio);
495void guard_bio_eod(struct bio *bio);
496void zero_fill_bio_iter(struct bio *bio, struct bvec_iter iter);
497
498static inline void zero_fill_bio(struct bio *bio)
499{
500 zero_fill_bio_iter(bio, iter: bio->bi_iter);
501}
502
503static inline void bio_release_pages(struct bio *bio, bool mark_dirty)
504{
505 if (bio_flagged(bio, bit: BIO_PAGE_PINNED))
506 __bio_release_pages(bio, mark_dirty);
507}
508
509#define bio_dev(bio) \
510 disk_devt((bio)->bi_bdev->bd_disk)
511
512#ifdef CONFIG_BLK_CGROUP
513void bio_associate_blkg(struct bio *bio);
514void bio_associate_blkg_from_css(struct bio *bio,
515 struct cgroup_subsys_state *css);
516void bio_clone_blkg_association(struct bio *dst, struct bio *src);
517void blkcg_punt_bio_submit(struct bio *bio);
518#else /* CONFIG_BLK_CGROUP */
519static inline void bio_associate_blkg(struct bio *bio) { }
520static inline void bio_associate_blkg_from_css(struct bio *bio,
521 struct cgroup_subsys_state *css)
522{ }
523static inline void bio_clone_blkg_association(struct bio *dst,
524 struct bio *src) { }
525static inline void blkcg_punt_bio_submit(struct bio *bio)
526{
527 submit_bio(bio);
528}
529#endif /* CONFIG_BLK_CGROUP */
530
531static inline void bio_set_dev(struct bio *bio, struct block_device *bdev)
532{
533 bio_clear_flag(bio, bit: BIO_REMAPPED);
534 if (bio->bi_bdev != bdev)
535 bio_clear_flag(bio, bit: BIO_BPS_THROTTLED);
536 bio->bi_bdev = bdev;
537 bio_associate_blkg(bio);
538}
539
540/*
541 * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
542 *
543 * A bio_list anchors a singly-linked list of bios chained through the bi_next
544 * member of the bio. The bio_list also caches the last list member to allow
545 * fast access to the tail.
546 */
547struct bio_list {
548 struct bio *head;
549 struct bio *tail;
550};
551
552static inline int bio_list_empty(const struct bio_list *bl)
553{
554 return bl->head == NULL;
555}
556
557static inline void bio_list_init(struct bio_list *bl)
558{
559 bl->head = bl->tail = NULL;
560}
561
562#define BIO_EMPTY_LIST { NULL, NULL }
563
564#define bio_list_for_each(bio, bl) \
565 for (bio = (bl)->head; bio; bio = bio->bi_next)
566
567static inline unsigned bio_list_size(const struct bio_list *bl)
568{
569 unsigned sz = 0;
570 struct bio *bio;
571
572 bio_list_for_each(bio, bl)
573 sz++;
574
575 return sz;
576}
577
578static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
579{
580 bio->bi_next = NULL;
581
582 if (bl->tail)
583 bl->tail->bi_next = bio;
584 else
585 bl->head = bio;
586
587 bl->tail = bio;
588}
589
590static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
591{
592 bio->bi_next = bl->head;
593
594 bl->head = bio;
595
596 if (!bl->tail)
597 bl->tail = bio;
598}
599
600static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
601{
602 if (!bl2->head)
603 return;
604
605 if (bl->tail)
606 bl->tail->bi_next = bl2->head;
607 else
608 bl->head = bl2->head;
609
610 bl->tail = bl2->tail;
611}
612
613static inline void bio_list_merge_head(struct bio_list *bl,
614 struct bio_list *bl2)
615{
616 if (!bl2->head)
617 return;
618
619 if (bl->head)
620 bl2->tail->bi_next = bl->head;
621 else
622 bl->tail = bl2->tail;
623
624 bl->head = bl2->head;
625}
626
627static inline struct bio *bio_list_peek(struct bio_list *bl)
628{
629 return bl->head;
630}
631
632static inline struct bio *bio_list_pop(struct bio_list *bl)
633{
634 struct bio *bio = bl->head;
635
636 if (bio) {
637 bl->head = bl->head->bi_next;
638 if (!bl->head)
639 bl->tail = NULL;
640
641 bio->bi_next = NULL;
642 }
643
644 return bio;
645}
646
647static inline struct bio *bio_list_get(struct bio_list *bl)
648{
649 struct bio *bio = bl->head;
650
651 bl->head = bl->tail = NULL;
652
653 return bio;
654}
655
656/*
657 * Increment chain count for the bio. Make sure the CHAIN flag update
658 * is visible before the raised count.
659 */
660static inline void bio_inc_remaining(struct bio *bio)
661{
662 bio_set_flag(bio, bit: BIO_CHAIN);
663 smp_mb__before_atomic();
664 atomic_inc(v: &bio->__bi_remaining);
665}
666
667/*
668 * bio_set is used to allow other portions of the IO system to
669 * allocate their own private memory pools for bio and iovec structures.
670 * These memory pools in turn all allocate from the bio_slab
671 * and the bvec_slabs[].
672 */
673#define BIO_POOL_SIZE 2
674
675struct bio_set {
676 struct kmem_cache *bio_slab;
677 unsigned int front_pad;
678
679 /*
680 * per-cpu bio alloc cache
681 */
682 struct bio_alloc_cache __percpu *cache;
683
684 mempool_t bio_pool;
685 mempool_t bvec_pool;
686#if defined(CONFIG_BLK_DEV_INTEGRITY)
687 mempool_t bio_integrity_pool;
688 mempool_t bvec_integrity_pool;
689#endif
690
691 unsigned int back_pad;
692 /*
693 * Deadlock avoidance for stacking block drivers: see comments in
694 * bio_alloc_bioset() for details
695 */
696 spinlock_t rescue_lock;
697 struct bio_list rescue_list;
698 struct work_struct rescue_work;
699 struct workqueue_struct *rescue_workqueue;
700
701 /*
702 * Hot un-plug notifier for the per-cpu cache, if used
703 */
704 struct hlist_node cpuhp_dead;
705};
706
707static inline bool bioset_initialized(struct bio_set *bs)
708{
709 return bs->bio_slab != NULL;
710}
711
712#if defined(CONFIG_BLK_DEV_INTEGRITY)
713
714#define bip_for_each_vec(bvl, bip, iter) \
715 for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
716
717#define bio_for_each_integrity_vec(_bvl, _bio, _iter) \
718 for_each_bio(_bio) \
719 bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
720
721extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
722extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
723extern bool bio_integrity_prep(struct bio *);
724extern void bio_integrity_advance(struct bio *, unsigned int);
725extern void bio_integrity_trim(struct bio *);
726extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t);
727extern int bioset_integrity_create(struct bio_set *, int);
728extern void bioset_integrity_free(struct bio_set *);
729extern void bio_integrity_init(void);
730
731#else /* CONFIG_BLK_DEV_INTEGRITY */
732
733static inline void *bio_integrity(struct bio *bio)
734{
735 return NULL;
736}
737
738static inline int bioset_integrity_create(struct bio_set *bs, int pool_size)
739{
740 return 0;
741}
742
743static inline void bioset_integrity_free (struct bio_set *bs)
744{
745 return;
746}
747
748static inline bool bio_integrity_prep(struct bio *bio)
749{
750 return true;
751}
752
753static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
754 gfp_t gfp_mask)
755{
756 return 0;
757}
758
759static inline void bio_integrity_advance(struct bio *bio,
760 unsigned int bytes_done)
761{
762 return;
763}
764
765static inline void bio_integrity_trim(struct bio *bio)
766{
767 return;
768}
769
770static inline void bio_integrity_init(void)
771{
772 return;
773}
774
775static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
776{
777 return false;
778}
779
780static inline void *bio_integrity_alloc(struct bio * bio, gfp_t gfp,
781 unsigned int nr)
782{
783 return ERR_PTR(-EINVAL);
784}
785
786static inline int bio_integrity_add_page(struct bio *bio, struct page *page,
787 unsigned int len, unsigned int offset)
788{
789 return 0;
790}
791
792#endif /* CONFIG_BLK_DEV_INTEGRITY */
793
794/*
795 * Mark a bio as polled. Note that for async polled IO, the caller must
796 * expect -EWOULDBLOCK if we cannot allocate a request (or other resources).
797 * We cannot block waiting for requests on polled IO, as those completions
798 * must be found by the caller. This is different than IRQ driven IO, where
799 * it's safe to wait for IO to complete.
800 */
801static inline void bio_set_polled(struct bio *bio, struct kiocb *kiocb)
802{
803 bio->bi_opf |= REQ_POLLED;
804 if (kiocb->ki_flags & IOCB_NOWAIT)
805 bio->bi_opf |= REQ_NOWAIT;
806}
807
808static inline void bio_clear_polled(struct bio *bio)
809{
810 bio->bi_opf &= ~REQ_POLLED;
811}
812
813struct bio *blk_next_bio(struct bio *bio, struct block_device *bdev,
814 unsigned int nr_pages, blk_opf_t opf, gfp_t gfp);
815
816#endif /* __LINUX_BIO_H */
817

source code of linux/include/linux/bio.h