Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
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#define BIO_MAX_INLINE_VECS UIO_MAXIOV
15
16struct queue_limits;
17
18static inline unsigned int bio_max_segs(unsigned int nr_segs)
19{
20 return min(nr_segs, BIO_MAX_VECS);
21}
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
49static inline bool bio_flagged(const struct bio *bio, unsigned int bit)
50{
51 return bio->bi_flags & (1U << bit);
52}
53
54static inline void bio_set_flag(struct bio *bio, unsigned int bit)
55{
56 bio->bi_flags |= (1U << bit);
57}
58
59static inline void bio_clear_flag(struct bio *bio, unsigned int bit)
60{
61 bio->bi_flags &= ~(1U << bit);
62}
63
64/*
65 * Check whether this bio carries any data or not. A NULL bio is allowed.
66 */
67static inline bool bio_has_data(struct bio *bio)
68{
69 if (bio &&
70 bio->bi_iter.bi_size &&
71 bio_op(bio) != REQ_OP_DISCARD &&
72 bio_op(bio) != REQ_OP_SECURE_ERASE &&
73 bio_op(bio) != REQ_OP_WRITE_ZEROES)
74 return true;
75
76 return false;
77}
78
79static inline bool bio_no_advance_iter(const struct bio *bio)
80{
81 return bio_op(bio) == REQ_OP_DISCARD ||
82 bio_op(bio) == REQ_OP_SECURE_ERASE ||
83 bio_op(bio) == REQ_OP_WRITE_ZEROES;
84}
85
86static inline void *bio_data(struct bio *bio)
87{
88 if (bio_has_data(bio))
89 return page_address(bio_page(bio)) + bio_offset(bio);
90
91 return NULL;
92}
93
94static inline bool bio_next_segment(const struct bio *bio,
95 struct bvec_iter_all *iter)
96{
97 if (iter->idx >= bio->bi_vcnt)
98 return false;
99
100 bvec_advance(&bio->bi_io_vec[iter->idx], iter);
101 return true;
102}
103
104/*
105 * drivers should _never_ use the all version - the bio may have been split
106 * before it got to the driver and the driver won't own all of it
107 */
108#define bio_for_each_segment_all(bvl, bio, iter) \
109 for (bvl = bvec_init_iter_all(&iter); bio_next_segment((bio), &iter); )
110
111static inline void bio_advance_iter(const struct bio *bio,
112 struct bvec_iter *iter, unsigned int bytes)
113{
114 iter->bi_sector += bytes >> 9;
115
116 if (bio_no_advance_iter(bio))
117 iter->bi_size -= bytes;
118 else
119 bvec_iter_advance(bio->bi_io_vec, iter, bytes);
120 /* TODO: It is reasonable to complete bio with error here. */
121}
122
123/* @bytes should be less or equal to bvec[i->bi_idx].bv_len */
124static inline void bio_advance_iter_single(const struct bio *bio,
125 struct bvec_iter *iter,
126 unsigned int bytes)
127{
128 iter->bi_sector += bytes >> 9;
129
130 if (bio_no_advance_iter(bio))
131 iter->bi_size -= bytes;
132 else
133 bvec_iter_advance_single(bio->bi_io_vec, iter, bytes);
134}
135
136void __bio_advance(struct bio *, unsigned bytes);
137
138/**
139 * bio_advance - increment/complete a bio by some number of bytes
140 * @bio: bio to advance
141 * @nbytes: number of bytes to complete
142 *
143 * This updates bi_sector, bi_size and bi_idx; if the number of bytes to
144 * complete doesn't align with a bvec boundary, then bv_len and bv_offset will
145 * be updated on the last bvec as well.
146 *
147 * @bio will then represent the remaining, uncompleted portion of the io.
148 */
149static inline void bio_advance(struct bio *bio, unsigned int nbytes)
150{
151 if (nbytes == bio->bi_iter.bi_size) {
152 bio->bi_iter.bi_size = 0;
153 return;
154 }
155 __bio_advance(bio, nbytes);
156}
157
158#define __bio_for_each_segment(bvl, bio, iter, start) \
159 for (iter = (start); \
160 (iter).bi_size && \
161 ((bvl = bio_iter_iovec((bio), (iter))), 1); \
162 bio_advance_iter_single((bio), &(iter), (bvl).bv_len))
163
164#define bio_for_each_segment(bvl, bio, iter) \
165 __bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter)
166
167#define __bio_for_each_bvec(bvl, bio, iter, start) \
168 for (iter = (start); \
169 (iter).bi_size && \
170 ((bvl = mp_bvec_iter_bvec((bio)->bi_io_vec, (iter))), 1); \
171 bio_advance_iter_single((bio), &(iter), (bvl).bv_len))
172
173/* iterate over multi-page bvec */
174#define bio_for_each_bvec(bvl, bio, iter) \
175 __bio_for_each_bvec(bvl, bio, iter, (bio)->bi_iter)
176
177/*
178 * Iterate over all multi-page bvecs. Drivers shouldn't use this version for the
179 * same reasons as bio_for_each_segment_all().
180 */
181#define bio_for_each_bvec_all(bvl, bio, i) \
182 for (i = 0, bvl = bio_first_bvec_all(bio); \
183 i < (bio)->bi_vcnt; i++, bvl++)
184
185#define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)
186
187static inline unsigned bio_segments(struct bio *bio)
188{
189 unsigned segs = 0;
190 struct bio_vec bv;
191 struct bvec_iter iter;
192
193 /*
194 * We special case discard/write same/write zeroes, because they
195 * interpret bi_size differently:
196 */
197
198 switch (bio_op(bio)) {
199 case REQ_OP_DISCARD:
200 case REQ_OP_SECURE_ERASE:
201 case REQ_OP_WRITE_ZEROES:
202 return 0;
203 default:
204 break;
205 }
206
207 bio_for_each_segment(bv, bio, iter)
208 segs++;
209
210 return segs;
211}
212
213/*
214 * get a reference to a bio, so it won't disappear. the intended use is
215 * something like:
216 *
217 * bio_get(bio);
218 * submit_bio(rw, bio);
219 * if (bio->bi_flags ...)
220 * do_something
221 * bio_put(bio);
222 *
223 * without the bio_get(), it could potentially complete I/O before submit_bio
224 * returns. and then bio would be freed memory when if (bio->bi_flags ...)
225 * runs
226 */
227static inline void bio_get(struct bio *bio)
228{
229 bio->bi_flags |= (1 << BIO_REFFED);
230 smp_mb__before_atomic();
231 atomic_inc(&bio->__bi_cnt);
232}
233
234static inline void bio_cnt_set(struct bio *bio, unsigned int count)
235{
236 if (count != 1) {
237 bio->bi_flags |= (1 << BIO_REFFED);
238 smp_mb();
239 }
240 atomic_set(&bio->__bi_cnt, count);
241}
242
243static inline struct bio_vec *bio_first_bvec_all(struct bio *bio)
244{
245 WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
246 return bio->bi_io_vec;
247}
248
249static inline struct page *bio_first_page_all(struct bio *bio)
250{
251 return bio_first_bvec_all(bio)->bv_page;
252}
253
254static inline struct folio *bio_first_folio_all(struct bio *bio)
255{
256 return page_folio(bio_first_page_all(bio));
257}
258
259/**
260 * struct folio_iter - State for iterating all folios in a bio.
261 * @folio: The current folio we're iterating. NULL after the last folio.
262 * @offset: The byte offset within the current folio.
263 * @length: The number of bytes in this iteration (will not cross folio
264 * boundary).
265 */
266struct folio_iter {
267 struct folio *folio;
268 size_t offset;
269 size_t length;
270 /* private: for use by the iterator */
271 struct folio *_next;
272 size_t _seg_count;
273 int _i;
274};
275
276static inline void bio_first_folio(struct folio_iter *fi, struct bio *bio,
277 int i)
278{
279 struct bio_vec *bvec = bio_first_bvec_all(bio) + i;
280
281 if (unlikely(i >= bio->bi_vcnt)) {
282 fi->folio = NULL;
283 return;
284 }
285
286 fi->folio = page_folio(bvec->bv_page);
287 fi->offset = bvec->bv_offset +
288 PAGE_SIZE * folio_page_idx(fi->folio, bvec->bv_page);
289 fi->_seg_count = bvec->bv_len;
290 fi->length = min(folio_size(fi->folio) - fi->offset, fi->_seg_count);
291 fi->_next = folio_next(fi->folio);
292 fi->_i = i;
293}
294
295static inline void bio_next_folio(struct folio_iter *fi, struct bio *bio)
296{
297 fi->_seg_count -= fi->length;
298 if (fi->_seg_count) {
299 fi->folio = fi->_next;
300 fi->offset = 0;
301 fi->length = min(folio_size(fi->folio), fi->_seg_count);
302 fi->_next = folio_next(fi->folio);
303 } else {
304 bio_first_folio(fi, bio, fi->_i + 1);
305 }
306}
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
316void bio_trim(struct bio *bio, sector_t offset, sector_t size);
317extern struct bio *bio_split(struct bio *bio, int sectors,
318 gfp_t gfp, struct bio_set *bs);
319int bio_split_io_at(struct bio *bio, const struct queue_limits *lim,
320 unsigned *segs, unsigned max_bytes, unsigned len_align);
321u8 bio_seg_gap(struct request_queue *q, struct bio *prev, struct bio *next,
322 u8 gaps_bit);
323
324/**
325 * bio_next_split - get next @sectors from a bio, splitting if necessary
326 * @bio: bio to split
327 * @sectors: number of sectors to split from the front of @bio
328 * @gfp: gfp mask
329 * @bs: bio set to allocate from
330 *
331 * Return: a bio representing the next @sectors of @bio - if the bio is smaller
332 * than @sectors, returns the original bio unchanged.
333 */
334static inline struct bio *bio_next_split(struct bio *bio, int sectors,
335 gfp_t gfp, struct bio_set *bs)
336{
337 if (sectors >= bio_sectors(bio))
338 return bio;
339
340 return bio_split(bio, sectors, gfp, bs);
341}
342
343enum {
344 BIOSET_NEED_BVECS = BIT(0),
345 BIOSET_NEED_RESCUER = BIT(1),
346 BIOSET_PERCPU_CACHE = BIT(2),
347};
348extern int bioset_init(struct bio_set *, unsigned int, unsigned int, int flags);
349extern void bioset_exit(struct bio_set *);
350extern int biovec_init_pool(mempool_t *pool, int pool_entries);
351
352struct bio *bio_alloc_bioset(struct block_device *bdev, unsigned short nr_vecs,
353 blk_opf_t opf, gfp_t gfp_mask,
354 struct bio_set *bs);
355struct bio *bio_kmalloc(unsigned short nr_vecs, gfp_t gfp_mask);
356extern void bio_put(struct bio *);
357
358struct bio *bio_alloc_clone(struct block_device *bdev, struct bio *bio_src,
359 gfp_t gfp, struct bio_set *bs);
360int bio_init_clone(struct block_device *bdev, struct bio *bio,
361 struct bio *bio_src, gfp_t gfp);
362
363extern struct bio_set fs_bio_set;
364
365static inline struct bio *bio_alloc(struct block_device *bdev,
366 unsigned short nr_vecs, blk_opf_t opf, gfp_t gfp_mask)
367{
368 return bio_alloc_bioset(bdev, nr_vecs, opf, gfp_mask, &fs_bio_set);
369}
370
371void submit_bio(struct bio *bio);
372
373extern void bio_endio(struct bio *);
374
375static inline void bio_io_error(struct bio *bio)
376{
377 bio->bi_status = BLK_STS_IOERR;
378 bio_endio(bio);
379}
380
381static inline void bio_wouldblock_error(struct bio *bio)
382{
383 bio_set_flag(bio, BIO_QUIET);
384 bio->bi_status = BLK_STS_AGAIN;
385 bio_endio(bio);
386}
387
388/*
389 * Calculate number of bvec segments that should be allocated to fit data
390 * pointed by @iter. If @iter is backed by bvec it's going to be reused
391 * instead of allocating a new one.
392 */
393static inline int bio_iov_vecs_to_alloc(struct iov_iter *iter, int max_segs)
394{
395 if (iov_iter_is_bvec(iter))
396 return 0;
397 return iov_iter_npages(iter, max_segs);
398}
399
400/**
401 * bio_iov_bounce_nr_vecs - calculate number of bvecs for a bounce bio
402 * @iter: iter to bounce from
403 * @op: REQ_OP_* for the bio
404 *
405 * Calculates how many bvecs are needed for the next bio to bounce from/to
406 * @iter.
407 */
408static inline unsigned short
409bio_iov_bounce_nr_vecs(struct iov_iter *iter, blk_opf_t op)
410{
411 /*
412 * We still need to bounce bvec iters, so don't special case them
413 * here unlike in bio_iov_vecs_to_alloc.
414 *
415 * For reads we need to use a vector for the bounce buffer, account
416 * for that here.
417 */
418 if (op_is_write(op))
419 return iov_iter_npages(iter, BIO_MAX_VECS);
420 return iov_iter_npages(iter, BIO_MAX_VECS - 1) + 1;
421}
422
423struct request_queue;
424
425void bio_init(struct bio *bio, struct block_device *bdev, struct bio_vec *table,
426 unsigned short max_vecs, blk_opf_t opf);
427static inline void bio_init_inline(struct bio *bio, struct block_device *bdev,
428 unsigned short max_vecs, blk_opf_t opf)
429{
430 bio_init(bio, bdev, bio_inline_vecs(bio), max_vecs, opf);
431}
432extern void bio_uninit(struct bio *);
433void bio_reset(struct bio *bio, struct block_device *bdev, blk_opf_t opf);
434void bio_reuse(struct bio *bio, blk_opf_t opf);
435void bio_chain(struct bio *, struct bio *);
436
437int __must_check bio_add_page(struct bio *bio, struct page *page, unsigned len,
438 unsigned off);
439bool __must_check bio_add_folio(struct bio *bio, struct folio *folio,
440 size_t len, size_t off);
441void __bio_add_page(struct bio *bio, struct page *page,
442 unsigned int len, unsigned int off);
443void bio_add_folio_nofail(struct bio *bio, struct folio *folio, size_t len,
444 size_t off);
445void bio_add_virt_nofail(struct bio *bio, void *vaddr, unsigned len);
446
447/**
448 * bio_add_max_vecs - number of bio_vecs needed to add data to a bio
449 * @kaddr: kernel virtual address to add
450 * @len: length in bytes to add
451 *
452 * Calculate how many bio_vecs need to be allocated to add the kernel virtual
453 * address range in [@kaddr:@len] in the worse case.
454 */
455static inline unsigned int bio_add_max_vecs(void *kaddr, unsigned int len)
456{
457 if (is_vmalloc_addr(kaddr))
458 return DIV_ROUND_UP(offset_in_page(kaddr) + len, PAGE_SIZE);
459 return 1;
460}
461
462unsigned int bio_add_vmalloc_chunk(struct bio *bio, void *vaddr, unsigned len);
463bool bio_add_vmalloc(struct bio *bio, void *vaddr, unsigned int len);
464
465int submit_bio_wait(struct bio *bio);
466int bdev_rw_virt(struct block_device *bdev, sector_t sector, void *data,
467 size_t len, enum req_op op);
468
469int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter,
470 unsigned len_align_mask);
471
472void bio_iov_bvec_set(struct bio *bio, const struct iov_iter *iter);
473void __bio_release_pages(struct bio *bio, bool mark_dirty);
474extern void bio_set_pages_dirty(struct bio *bio);
475extern void bio_check_pages_dirty(struct bio *bio);
476
477int bio_iov_iter_bounce(struct bio *bio, struct iov_iter *iter);
478void bio_iov_iter_unbounce(struct bio *bio, bool is_error, bool mark_dirty);
479
480extern void bio_copy_data_iter(struct bio *dst, struct bvec_iter *dst_iter,
481 struct bio *src, struct bvec_iter *src_iter);
482extern void bio_copy_data(struct bio *dst, struct bio *src);
483extern void bio_free_pages(struct bio *bio);
484void guard_bio_eod(struct bio *bio);
485void zero_fill_bio_iter(struct bio *bio, struct bvec_iter iter);
486
487static inline void zero_fill_bio(struct bio *bio)
488{
489 zero_fill_bio_iter(bio, bio->bi_iter);
490}
491
492static inline void bio_release_pages(struct bio *bio, bool mark_dirty)
493{
494 if (bio_flagged(bio, BIO_PAGE_PINNED))
495 __bio_release_pages(bio, mark_dirty);
496}
497
498#define bio_dev(bio) \
499 disk_devt((bio)->bi_bdev->bd_disk)
500
501#ifdef CONFIG_BLK_CGROUP
502void bio_associate_blkg(struct bio *bio);
503void bio_associate_blkg_from_css(struct bio *bio,
504 struct cgroup_subsys_state *css);
505void bio_clone_blkg_association(struct bio *dst, struct bio *src);
506void blkcg_punt_bio_submit(struct bio *bio);
507#else /* CONFIG_BLK_CGROUP */
508static inline void bio_associate_blkg(struct bio *bio) { }
509static inline void bio_associate_blkg_from_css(struct bio *bio,
510 struct cgroup_subsys_state *css)
511{ }
512static inline void bio_clone_blkg_association(struct bio *dst,
513 struct bio *src) { }
514static inline void blkcg_punt_bio_submit(struct bio *bio)
515{
516 submit_bio(bio);
517}
518#endif /* CONFIG_BLK_CGROUP */
519
520static inline void bio_set_dev(struct bio *bio, struct block_device *bdev)
521{
522 bio_clear_flag(bio, BIO_REMAPPED);
523 if (bio->bi_bdev != bdev)
524 bio_clear_flag(bio, BIO_BPS_THROTTLED);
525 bio->bi_bdev = bdev;
526 bio_associate_blkg(bio);
527}
528
529/*
530 * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
531 *
532 * A bio_list anchors a singly-linked list of bios chained through the bi_next
533 * member of the bio. The bio_list also caches the last list member to allow
534 * fast access to the tail.
535 */
536struct bio_list {
537 struct bio *head;
538 struct bio *tail;
539};
540
541static inline int bio_list_empty(const struct bio_list *bl)
542{
543 return bl->head == NULL;
544}
545
546static inline void bio_list_init(struct bio_list *bl)
547{
548 bl->head = bl->tail = NULL;
549}
550
551#define BIO_EMPTY_LIST { NULL, NULL }
552
553#define bio_list_for_each(bio, bl) \
554 for (bio = (bl)->head; bio; bio = bio->bi_next)
555
556static inline unsigned bio_list_size(const struct bio_list *bl)
557{
558 unsigned sz = 0;
559 struct bio *bio;
560
561 bio_list_for_each(bio, bl)
562 sz++;
563
564 return sz;
565}
566
567static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
568{
569 bio->bi_next = NULL;
570
571 if (bl->tail)
572 bl->tail->bi_next = bio;
573 else
574 bl->head = bio;
575
576 bl->tail = bio;
577}
578
579static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
580{
581 bio->bi_next = bl->head;
582
583 bl->head = bio;
584
585 if (!bl->tail)
586 bl->tail = bio;
587}
588
589static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
590{
591 if (!bl2->head)
592 return;
593
594 if (bl->tail)
595 bl->tail->bi_next = bl2->head;
596 else
597 bl->head = bl2->head;
598
599 bl->tail = bl2->tail;
600}
601
602static inline void bio_list_merge_init(struct bio_list *bl,
603 struct bio_list *bl2)
604{
605 bio_list_merge(bl, bl2);
606 bio_list_init(bl2);
607}
608
609static inline void bio_list_merge_head(struct bio_list *bl,
610 struct bio_list *bl2)
611{
612 if (!bl2->head)
613 return;
614
615 if (bl->head)
616 bl2->tail->bi_next = bl->head;
617 else
618 bl->tail = bl2->tail;
619
620 bl->head = bl2->head;
621}
622
623static inline struct bio *bio_list_peek(struct bio_list *bl)
624{
625 return bl->head;
626}
627
628static inline struct bio *bio_list_pop(struct bio_list *bl)
629{
630 struct bio *bio = bl->head;
631
632 if (bio) {
633 bl->head = bl->head->bi_next;
634 if (!bl->head)
635 bl->tail = NULL;
636
637 bio->bi_next = NULL;
638 }
639
640 return bio;
641}
642
643static inline struct bio *bio_list_get(struct bio_list *bl)
644{
645 struct bio *bio = bl->head;
646
647 bl->head = bl->tail = NULL;
648
649 return bio;
650}
651
652/*
653 * Increment chain count for the bio. Make sure the CHAIN flag update
654 * is visible before the raised count.
655 */
656static inline void bio_inc_remaining(struct bio *bio)
657{
658 bio_set_flag(bio, BIO_CHAIN);
659 smp_mb__before_atomic();
660 atomic_inc(&bio->__bi_remaining);
661}
662
663/*
664 * bio_set is used to allow other portions of the IO system to
665 * allocate their own private memory pools for bio and iovec structures.
666 * These memory pools in turn all allocate from the bio_slab
667 * and the bvec_slabs[].
668 */
669#define BIO_POOL_SIZE 2
670
671struct bio_set {
672 struct kmem_cache *bio_slab;
673 unsigned int front_pad;
674
675 /*
676 * per-cpu bio alloc cache
677 */
678 struct bio_alloc_cache __percpu *cache;
679
680 mempool_t bio_pool;
681 mempool_t bvec_pool;
682
683 unsigned int back_pad;
684 /*
685 * Deadlock avoidance for stacking block drivers: see comments in
686 * bio_alloc_bioset() for details
687 */
688 spinlock_t rescue_lock;
689 struct bio_list rescue_list;
690 struct work_struct rescue_work;
691 struct workqueue_struct *rescue_workqueue;
692
693 /*
694 * Hot un-plug notifier for the per-cpu cache, if used
695 */
696 struct hlist_node cpuhp_dead;
697};
698
699static inline bool bioset_initialized(struct bio_set *bs)
700{
701 return bs->bio_slab != NULL;
702}
703
704/*
705 * Mark a bio as polled. Note that for async polled IO, the caller must
706 * expect -EWOULDBLOCK if we cannot allocate a request (or other resources).
707 * We cannot block waiting for requests on polled IO, as those completions
708 * must be found by the caller. This is different than IRQ driven IO, where
709 * it's safe to wait for IO to complete.
710 */
711static inline void bio_set_polled(struct bio *bio, struct kiocb *kiocb)
712{
713 bio->bi_opf |= REQ_POLLED;
714 if (kiocb->ki_flags & IOCB_NOWAIT)
715 bio->bi_opf |= REQ_NOWAIT;
716}
717
718static inline void bio_clear_polled(struct bio *bio)
719{
720 bio->bi_opf &= ~REQ_POLLED;
721}
722
723/**
724 * bio_is_zone_append - is this a zone append bio?
725 * @bio: bio to check
726 *
727 * Check if @bio is a zone append operation. Core block layer code and end_io
728 * handlers must use this instead of an open coded REQ_OP_ZONE_APPEND check
729 * because the block layer can rewrite REQ_OP_ZONE_APPEND to REQ_OP_WRITE if
730 * it is not natively supported.
731 */
732static inline bool bio_is_zone_append(struct bio *bio)
733{
734 if (!IS_ENABLED(CONFIG_BLK_DEV_ZONED))
735 return false;
736 return bio_op(bio) == REQ_OP_ZONE_APPEND ||
737 bio_flagged(bio, BIO_EMULATES_ZONE_APPEND);
738}
739
740struct bio *blk_next_bio(struct bio *bio, struct block_device *bdev,
741 unsigned int nr_pages, blk_opf_t opf, gfp_t gfp);
742struct bio *bio_chain_and_submit(struct bio *prev, struct bio *new);
743
744struct bio *blk_alloc_discard_bio(struct block_device *bdev,
745 sector_t *sector, sector_t *nr_sects, gfp_t gfp_mask);
746
747#endif /* __LINUX_BIO_H */