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 : struct queue_limits;
16 :
17 : static inline unsigned int bio_max_segs(unsigned int nr_segs)
18 : {
19 0 : 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 : */
54 : static inline bool bio_has_data(struct bio *bio)
55 : {
56 0 : if (bio &&
57 0 : bio->bi_iter.bi_size &&
58 0 : bio_op(bio) != REQ_OP_DISCARD &&
59 0 : bio_op(bio) != REQ_OP_SECURE_ERASE &&
60 0 : bio_op(bio) != REQ_OP_WRITE_ZEROES)
61 : return true;
62 :
63 : return false;
64 : }
65 :
66 : static inline bool bio_no_advance_iter(const struct bio *bio)
67 : {
68 0 : return bio_op(bio) == REQ_OP_DISCARD ||
69 0 : bio_op(bio) == REQ_OP_SECURE_ERASE ||
70 0 : bio_op(bio) == REQ_OP_WRITE_ZEROES;
71 : }
72 :
73 : static 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 :
81 : static inline bool bio_next_segment(const struct bio *bio,
82 : struct bvec_iter_all *iter)
83 : {
84 0 : if (iter->idx >= bio->bi_vcnt)
85 : return false;
86 :
87 0 : bvec_advance(&bio->bi_io_vec[iter->idx], 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 :
98 0 : static inline void bio_advance_iter(const struct bio *bio,
99 : struct bvec_iter *iter, unsigned int bytes)
100 : {
101 0 : iter->bi_sector += bytes >> 9;
102 :
103 0 : if (bio_no_advance_iter(bio))
104 0 : iter->bi_size -= bytes;
105 : else
106 0 : bvec_iter_advance(bio->bi_io_vec, iter, bytes);
107 : /* TODO: It is reasonable to complete bio with error here. */
108 0 : }
109 :
110 : /* @bytes should be less or equal to bvec[i->bi_idx].bv_len */
111 0 : static inline void bio_advance_iter_single(const struct bio *bio,
112 : struct bvec_iter *iter,
113 : unsigned int bytes)
114 : {
115 0 : iter->bi_sector += bytes >> 9;
116 :
117 0 : if (bio_no_advance_iter(bio))
118 0 : iter->bi_size -= bytes;
119 : else
120 0 : bvec_iter_advance_single(bio->bi_io_vec, iter, bytes);
121 0 : }
122 :
123 : void __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 : */
136 : static inline void bio_advance(struct bio *bio, unsigned int nbytes)
137 : {
138 0 : if (nbytes == bio->bi_iter.bi_size) {
139 0 : bio->bi_iter.bi_size = 0;
140 : return;
141 : }
142 0 : __bio_advance(bio, 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 :
174 : static 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 : */
214 : static inline void bio_get(struct bio *bio)
215 : {
216 0 : bio->bi_flags |= (1 << BIO_REFFED);
217 0 : smp_mb__before_atomic();
218 0 : atomic_inc(&bio->__bi_cnt);
219 : }
220 :
221 : static 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(&bio->__bi_cnt, count);
228 : }
229 :
230 : static inline bool bio_flagged(struct bio *bio, unsigned int bit)
231 : {
232 0 : return (bio->bi_flags & (1U << bit)) != 0;
233 : }
234 :
235 : static inline void bio_set_flag(struct bio *bio, unsigned int bit)
236 : {
237 0 : bio->bi_flags |= (1U << bit);
238 : }
239 :
240 : static inline void bio_clear_flag(struct bio *bio, unsigned int bit)
241 : {
242 0 : bio->bi_flags &= ~(1U << bit);
243 : }
244 :
245 0 : static inline struct bio_vec *bio_first_bvec_all(struct bio *bio)
246 : {
247 0 : WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
248 0 : return bio->bi_io_vec;
249 : }
250 :
251 : static inline struct page *bio_first_page_all(struct bio *bio)
252 : {
253 0 : return bio_first_bvec_all(bio)->bv_page;
254 : }
255 :
256 : static inline struct bio_vec *bio_last_bvec_all(struct bio *bio)
257 : {
258 : WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
259 : return &bio->bi_io_vec[bio->bi_vcnt - 1];
260 : }
261 :
262 : /**
263 : * struct folio_iter - State for iterating all folios in a bio.
264 : * @folio: The current folio we're iterating. NULL after the last folio.
265 : * @offset: The byte offset within the current folio.
266 : * @length: The number of bytes in this iteration (will not cross folio
267 : * boundary).
268 : */
269 : struct folio_iter {
270 : struct folio *folio;
271 : size_t offset;
272 : size_t length;
273 : /* private: for use by the iterator */
274 : struct folio *_next;
275 : size_t _seg_count;
276 : int _i;
277 : };
278 :
279 0 : static inline void bio_first_folio(struct folio_iter *fi, struct bio *bio,
280 : int i)
281 : {
282 0 : struct bio_vec *bvec = bio_first_bvec_all(bio) + i;
283 :
284 0 : fi->folio = page_folio(bvec->bv_page);
285 0 : fi->offset = bvec->bv_offset +
286 0 : PAGE_SIZE * (bvec->bv_page - &fi->folio->page);
287 0 : fi->_seg_count = bvec->bv_len;
288 0 : fi->length = min(folio_size(fi->folio) - fi->offset, fi->_seg_count);
289 0 : fi->_next = folio_next(fi->folio);
290 0 : fi->_i = i;
291 0 : }
292 :
293 0 : static inline void bio_next_folio(struct folio_iter *fi, struct bio *bio)
294 : {
295 0 : fi->_seg_count -= fi->length;
296 0 : if (fi->_seg_count) {
297 0 : fi->folio = fi->_next;
298 0 : fi->offset = 0;
299 0 : fi->length = min(folio_size(fi->folio), fi->_seg_count);
300 0 : fi->_next = folio_next(fi->folio);
301 0 : } else if (fi->_i + 1 < bio->bi_vcnt) {
302 0 : bio_first_folio(fi, bio, fi->_i + 1);
303 : } else {
304 0 : fi->folio = NULL;
305 : }
306 0 : }
307 :
308 : /**
309 : * bio_for_each_folio_all - Iterate over each folio in a bio.
310 : * @fi: struct folio_iter which is updated for each folio.
311 : * @bio: struct bio to iterate over.
312 : */
313 : #define bio_for_each_folio_all(fi, bio) \
314 : for (bio_first_folio(&fi, bio, 0); fi.folio; bio_next_folio(&fi, bio))
315 :
316 : enum bip_flags {
317 : BIP_BLOCK_INTEGRITY = 1 << 0, /* block layer owns integrity data */
318 : BIP_MAPPED_INTEGRITY = 1 << 1, /* ref tag has been remapped */
319 : BIP_CTRL_NOCHECK = 1 << 2, /* disable HBA integrity checking */
320 : BIP_DISK_NOCHECK = 1 << 3, /* disable disk integrity checking */
321 : BIP_IP_CHECKSUM = 1 << 4, /* IP checksum */
322 : };
323 :
324 : /*
325 : * bio integrity payload
326 : */
327 : struct bio_integrity_payload {
328 : struct bio *bip_bio; /* parent bio */
329 :
330 : struct bvec_iter bip_iter;
331 :
332 : unsigned short bip_vcnt; /* # of integrity bio_vecs */
333 : unsigned short bip_max_vcnt; /* integrity bio_vec slots */
334 : unsigned short bip_flags; /* control flags */
335 :
336 : struct bvec_iter bio_iter; /* for rewinding parent bio */
337 :
338 : struct work_struct bip_work; /* I/O completion */
339 :
340 : struct bio_vec *bip_vec;
341 : struct bio_vec bip_inline_vecs[];/* embedded bvec array */
342 : };
343 :
344 : #if defined(CONFIG_BLK_DEV_INTEGRITY)
345 :
346 : static inline struct bio_integrity_payload *bio_integrity(struct bio *bio)
347 : {
348 : if (bio->bi_opf & REQ_INTEGRITY)
349 : return bio->bi_integrity;
350 :
351 : return NULL;
352 : }
353 :
354 : static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
355 : {
356 : struct bio_integrity_payload *bip = bio_integrity(bio);
357 :
358 : if (bip)
359 : return bip->bip_flags & flag;
360 :
361 : return false;
362 : }
363 :
364 : static inline sector_t bip_get_seed(struct bio_integrity_payload *bip)
365 : {
366 : return bip->bip_iter.bi_sector;
367 : }
368 :
369 : static inline void bip_set_seed(struct bio_integrity_payload *bip,
370 : sector_t seed)
371 : {
372 : bip->bip_iter.bi_sector = seed;
373 : }
374 :
375 : #endif /* CONFIG_BLK_DEV_INTEGRITY */
376 :
377 : void bio_trim(struct bio *bio, sector_t offset, sector_t size);
378 : extern struct bio *bio_split(struct bio *bio, int sectors,
379 : gfp_t gfp, struct bio_set *bs);
380 : struct bio *bio_split_rw(struct bio *bio, const struct queue_limits *lim,
381 : unsigned *segs, struct bio_set *bs, unsigned max_bytes);
382 :
383 : /**
384 : * bio_next_split - get next @sectors from a bio, splitting if necessary
385 : * @bio: bio to split
386 : * @sectors: number of sectors to split from the front of @bio
387 : * @gfp: gfp mask
388 : * @bs: bio set to allocate from
389 : *
390 : * Return: a bio representing the next @sectors of @bio - if the bio is smaller
391 : * than @sectors, returns the original bio unchanged.
392 : */
393 : static inline struct bio *bio_next_split(struct bio *bio, int sectors,
394 : gfp_t gfp, struct bio_set *bs)
395 : {
396 : if (sectors >= bio_sectors(bio))
397 : return bio;
398 :
399 : return bio_split(bio, sectors, gfp, bs);
400 : }
401 :
402 : enum {
403 : BIOSET_NEED_BVECS = BIT(0),
404 : BIOSET_NEED_RESCUER = BIT(1),
405 : BIOSET_PERCPU_CACHE = BIT(2),
406 : };
407 : extern int bioset_init(struct bio_set *, unsigned int, unsigned int, int flags);
408 : extern void bioset_exit(struct bio_set *);
409 : extern int biovec_init_pool(mempool_t *pool, int pool_entries);
410 :
411 : struct bio *bio_alloc_bioset(struct block_device *bdev, unsigned short nr_vecs,
412 : blk_opf_t opf, gfp_t gfp_mask,
413 : struct bio_set *bs);
414 : struct bio *bio_kmalloc(unsigned short nr_vecs, gfp_t gfp_mask);
415 : extern void bio_put(struct bio *);
416 :
417 : struct bio *bio_alloc_clone(struct block_device *bdev, struct bio *bio_src,
418 : gfp_t gfp, struct bio_set *bs);
419 : int bio_init_clone(struct block_device *bdev, struct bio *bio,
420 : struct bio *bio_src, gfp_t gfp);
421 :
422 : extern struct bio_set fs_bio_set;
423 :
424 : static inline struct bio *bio_alloc(struct block_device *bdev,
425 : unsigned short nr_vecs, blk_opf_t opf, gfp_t gfp_mask)
426 : {
427 0 : return bio_alloc_bioset(bdev, nr_vecs, opf, gfp_mask, &fs_bio_set);
428 : }
429 :
430 : void submit_bio(struct bio *bio);
431 :
432 : extern void bio_endio(struct bio *);
433 :
434 : static inline void bio_io_error(struct bio *bio)
435 : {
436 0 : bio->bi_status = BLK_STS_IOERR;
437 0 : bio_endio(bio);
438 : }
439 :
440 : static inline void bio_wouldblock_error(struct bio *bio)
441 : {
442 0 : bio_set_flag(bio, BIO_QUIET);
443 0 : bio->bi_status = BLK_STS_AGAIN;
444 0 : bio_endio(bio);
445 : }
446 :
447 : /*
448 : * Calculate number of bvec segments that should be allocated to fit data
449 : * pointed by @iter. If @iter is backed by bvec it's going to be reused
450 : * instead of allocating a new one.
451 : */
452 : static inline int bio_iov_vecs_to_alloc(struct iov_iter *iter, int max_segs)
453 : {
454 0 : if (iov_iter_is_bvec(iter))
455 : return 0;
456 0 : return iov_iter_npages(iter, max_segs);
457 : }
458 :
459 : struct request_queue;
460 :
461 : extern int submit_bio_wait(struct bio *bio);
462 : void bio_init(struct bio *bio, struct block_device *bdev, struct bio_vec *table,
463 : unsigned short max_vecs, blk_opf_t opf);
464 : extern void bio_uninit(struct bio *);
465 : void bio_reset(struct bio *bio, struct block_device *bdev, blk_opf_t opf);
466 : void bio_chain(struct bio *, struct bio *);
467 :
468 : int bio_add_page(struct bio *, struct page *, unsigned len, unsigned off);
469 : bool bio_add_folio(struct bio *, struct folio *, size_t len, size_t off);
470 : extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
471 : unsigned int, unsigned int);
472 : int bio_add_zone_append_page(struct bio *bio, struct page *page,
473 : unsigned int len, unsigned int offset);
474 : void __bio_add_page(struct bio *bio, struct page *page,
475 : unsigned int len, unsigned int off);
476 : int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter);
477 : void bio_iov_bvec_set(struct bio *bio, struct iov_iter *iter);
478 : void __bio_release_pages(struct bio *bio, bool mark_dirty);
479 : extern void bio_set_pages_dirty(struct bio *bio);
480 : extern void bio_check_pages_dirty(struct bio *bio);
481 :
482 : extern void bio_copy_data_iter(struct bio *dst, struct bvec_iter *dst_iter,
483 : struct bio *src, struct bvec_iter *src_iter);
484 : extern void bio_copy_data(struct bio *dst, struct bio *src);
485 : extern void bio_free_pages(struct bio *bio);
486 : void guard_bio_eod(struct bio *bio);
487 : void zero_fill_bio(struct bio *bio);
488 :
489 : static inline void bio_release_pages(struct bio *bio, bool mark_dirty)
490 : {
491 0 : if (!bio_flagged(bio, BIO_NO_PAGE_REF))
492 0 : __bio_release_pages(bio, mark_dirty);
493 : }
494 :
495 : #define bio_dev(bio) \
496 : disk_devt((bio)->bi_bdev->bd_disk)
497 :
498 : #ifdef CONFIG_BLK_CGROUP
499 : void bio_associate_blkg(struct bio *bio);
500 : void bio_associate_blkg_from_css(struct bio *bio,
501 : struct cgroup_subsys_state *css);
502 : void bio_clone_blkg_association(struct bio *dst, struct bio *src);
503 : void blkcg_punt_bio_submit(struct bio *bio);
504 : #else /* CONFIG_BLK_CGROUP */
505 : static inline void bio_associate_blkg(struct bio *bio) { }
506 : static inline void bio_associate_blkg_from_css(struct bio *bio,
507 : struct cgroup_subsys_state *css)
508 : { }
509 : static inline void bio_clone_blkg_association(struct bio *dst,
510 : struct bio *src) { }
511 : static inline void blkcg_punt_bio_submit(struct bio *bio)
512 : {
513 : submit_bio(bio);
514 : }
515 : #endif /* CONFIG_BLK_CGROUP */
516 :
517 : static inline void bio_set_dev(struct bio *bio, struct block_device *bdev)
518 : {
519 : bio_clear_flag(bio, BIO_REMAPPED);
520 : if (bio->bi_bdev != bdev)
521 : bio_clear_flag(bio, BIO_BPS_THROTTLED);
522 : bio->bi_bdev = bdev;
523 : bio_associate_blkg(bio);
524 : }
525 :
526 : /*
527 : * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
528 : *
529 : * A bio_list anchors a singly-linked list of bios chained through the bi_next
530 : * member of the bio. The bio_list also caches the last list member to allow
531 : * fast access to the tail.
532 : */
533 : struct bio_list {
534 : struct bio *head;
535 : struct bio *tail;
536 : };
537 :
538 : static inline int bio_list_empty(const struct bio_list *bl)
539 : {
540 : return bl->head == NULL;
541 : }
542 :
543 : static inline void bio_list_init(struct bio_list *bl)
544 : {
545 2 : bl->head = bl->tail = NULL;
546 : }
547 :
548 : #define BIO_EMPTY_LIST { NULL, NULL }
549 :
550 : #define bio_list_for_each(bio, bl) \
551 : for (bio = (bl)->head; bio; bio = bio->bi_next)
552 :
553 : static inline unsigned bio_list_size(const struct bio_list *bl)
554 : {
555 : unsigned sz = 0;
556 : struct bio *bio;
557 :
558 : bio_list_for_each(bio, bl)
559 : sz++;
560 :
561 : return sz;
562 : }
563 :
564 : static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
565 : {
566 0 : bio->bi_next = NULL;
567 :
568 0 : if (bl->tail)
569 0 : bl->tail->bi_next = bio;
570 : else
571 0 : bl->head = bio;
572 :
573 0 : bl->tail = bio;
574 : }
575 :
576 : static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
577 : {
578 : bio->bi_next = bl->head;
579 :
580 : bl->head = bio;
581 :
582 : if (!bl->tail)
583 : bl->tail = bio;
584 : }
585 :
586 : static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
587 : {
588 0 : if (!bl2->head)
589 : return;
590 :
591 0 : if (bl->tail)
592 0 : bl->tail->bi_next = bl2->head;
593 : else
594 0 : bl->head = bl2->head;
595 :
596 0 : bl->tail = bl2->tail;
597 : }
598 :
599 : static inline void bio_list_merge_head(struct bio_list *bl,
600 : struct bio_list *bl2)
601 : {
602 : if (!bl2->head)
603 : return;
604 :
605 : if (bl->head)
606 : bl2->tail->bi_next = bl->head;
607 : else
608 : bl->tail = bl2->tail;
609 :
610 : bl->head = bl2->head;
611 : }
612 :
613 : static inline struct bio *bio_list_peek(struct bio_list *bl)
614 : {
615 : return bl->head;
616 : }
617 :
618 : static inline struct bio *bio_list_pop(struct bio_list *bl)
619 : {
620 0 : struct bio *bio = bl->head;
621 :
622 0 : if (bio) {
623 0 : bl->head = bl->head->bi_next;
624 0 : if (!bl->head)
625 0 : bl->tail = NULL;
626 :
627 0 : bio->bi_next = NULL;
628 : }
629 :
630 : return bio;
631 : }
632 :
633 : static inline struct bio *bio_list_get(struct bio_list *bl)
634 : {
635 : struct bio *bio = bl->head;
636 :
637 : bl->head = bl->tail = NULL;
638 :
639 : return bio;
640 : }
641 :
642 : /*
643 : * Increment chain count for the bio. Make sure the CHAIN flag update
644 : * is visible before the raised count.
645 : */
646 : static inline void bio_inc_remaining(struct bio *bio)
647 : {
648 0 : bio_set_flag(bio, BIO_CHAIN);
649 0 : smp_mb__before_atomic();
650 0 : atomic_inc(&bio->__bi_remaining);
651 : }
652 :
653 : /*
654 : * bio_set is used to allow other portions of the IO system to
655 : * allocate their own private memory pools for bio and iovec structures.
656 : * These memory pools in turn all allocate from the bio_slab
657 : * and the bvec_slabs[].
658 : */
659 : #define BIO_POOL_SIZE 2
660 :
661 : struct bio_set {
662 : struct kmem_cache *bio_slab;
663 : unsigned int front_pad;
664 :
665 : /*
666 : * per-cpu bio alloc cache
667 : */
668 : struct bio_alloc_cache __percpu *cache;
669 :
670 : mempool_t bio_pool;
671 : mempool_t bvec_pool;
672 : #if defined(CONFIG_BLK_DEV_INTEGRITY)
673 : mempool_t bio_integrity_pool;
674 : mempool_t bvec_integrity_pool;
675 : #endif
676 :
677 : unsigned int back_pad;
678 : /*
679 : * Deadlock avoidance for stacking block drivers: see comments in
680 : * bio_alloc_bioset() for details
681 : */
682 : spinlock_t rescue_lock;
683 : struct bio_list rescue_list;
684 : struct work_struct rescue_work;
685 : struct workqueue_struct *rescue_workqueue;
686 :
687 : /*
688 : * Hot un-plug notifier for the per-cpu cache, if used
689 : */
690 : struct hlist_node cpuhp_dead;
691 : };
692 :
693 : static inline bool bioset_initialized(struct bio_set *bs)
694 : {
695 : return bs->bio_slab != NULL;
696 : }
697 :
698 : #if defined(CONFIG_BLK_DEV_INTEGRITY)
699 :
700 : #define bip_for_each_vec(bvl, bip, iter) \
701 : for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
702 :
703 : #define bio_for_each_integrity_vec(_bvl, _bio, _iter) \
704 : for_each_bio(_bio) \
705 : bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
706 :
707 : extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
708 : extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
709 : extern bool bio_integrity_prep(struct bio *);
710 : extern void bio_integrity_advance(struct bio *, unsigned int);
711 : extern void bio_integrity_trim(struct bio *);
712 : extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t);
713 : extern int bioset_integrity_create(struct bio_set *, int);
714 : extern void bioset_integrity_free(struct bio_set *);
715 : extern void bio_integrity_init(void);
716 :
717 : #else /* CONFIG_BLK_DEV_INTEGRITY */
718 :
719 : static inline void *bio_integrity(struct bio *bio)
720 : {
721 : return NULL;
722 : }
723 :
724 : static inline int bioset_integrity_create(struct bio_set *bs, int pool_size)
725 : {
726 : return 0;
727 : }
728 :
729 : static inline void bioset_integrity_free (struct bio_set *bs)
730 : {
731 : return;
732 : }
733 :
734 : static inline bool bio_integrity_prep(struct bio *bio)
735 : {
736 : return true;
737 : }
738 :
739 : static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
740 : gfp_t gfp_mask)
741 : {
742 : return 0;
743 : }
744 :
745 : static inline void bio_integrity_advance(struct bio *bio,
746 : unsigned int bytes_done)
747 : {
748 : return;
749 : }
750 :
751 : static inline void bio_integrity_trim(struct bio *bio)
752 : {
753 : return;
754 : }
755 :
756 : static inline void bio_integrity_init(void)
757 : {
758 : return;
759 : }
760 :
761 : static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
762 : {
763 : return false;
764 : }
765 :
766 : static inline void *bio_integrity_alloc(struct bio * bio, gfp_t gfp,
767 : unsigned int nr)
768 : {
769 : return ERR_PTR(-EINVAL);
770 : }
771 :
772 : static inline int bio_integrity_add_page(struct bio *bio, struct page *page,
773 : unsigned int len, unsigned int offset)
774 : {
775 : return 0;
776 : }
777 :
778 : #endif /* CONFIG_BLK_DEV_INTEGRITY */
779 :
780 : /*
781 : * Mark a bio as polled. Note that for async polled IO, the caller must
782 : * expect -EWOULDBLOCK if we cannot allocate a request (or other resources).
783 : * We cannot block waiting for requests on polled IO, as those completions
784 : * must be found by the caller. This is different than IRQ driven IO, where
785 : * it's safe to wait for IO to complete.
786 : */
787 : static inline void bio_set_polled(struct bio *bio, struct kiocb *kiocb)
788 : {
789 : bio->bi_opf |= REQ_POLLED;
790 : if (!is_sync_kiocb(kiocb))
791 : bio->bi_opf |= REQ_NOWAIT;
792 : }
793 :
794 : static inline void bio_clear_polled(struct bio *bio)
795 : {
796 0 : bio->bi_opf &= ~REQ_POLLED;
797 : }
798 :
799 : struct bio *blk_next_bio(struct bio *bio, struct block_device *bdev,
800 : unsigned int nr_pages, blk_opf_t opf, gfp_t gfp);
801 :
802 : #endif /* __LINUX_BIO_H */
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