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