Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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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, struct bio_set *bs);
354struct bio *bio_kmalloc(unsigned short nr_vecs, gfp_t gfp_mask);
355extern void bio_put(struct bio *);
356
357struct bio *bio_alloc_clone(struct block_device *bdev, struct bio *bio_src,
358 gfp_t gfp, struct bio_set *bs);
359int bio_init_clone(struct block_device *bdev, struct bio *bio,
360 struct bio *bio_src, gfp_t gfp);
361
362extern struct bio_set fs_bio_set;
363
364static inline struct bio *bio_alloc(struct block_device *bdev,
365 unsigned short nr_vecs, blk_opf_t opf, gfp_t gfp_mask)
366{
367 return bio_alloc_bioset(bdev, nr_vecs, opf, gfp_mask, &fs_bio_set);
368}
369
370void submit_bio(struct bio *bio);
371
372extern void bio_endio(struct bio *);
373
374static inline void bio_io_error(struct bio *bio)
375{
376 bio->bi_status = BLK_STS_IOERR;
377 bio_endio(bio);
378}
379
380static inline void bio_wouldblock_error(struct bio *bio)
381{
382 bio_set_flag(bio, BIO_QUIET);
383 bio->bi_status = BLK_STS_AGAIN;
384 bio_endio(bio);
385}
386
387/*
388 * Calculate number of bvec segments that should be allocated to fit data
389 * pointed by @iter. If @iter is backed by bvec it's going to be reused
390 * instead of allocating a new one.
391 */
392static inline int bio_iov_vecs_to_alloc(struct iov_iter *iter, int max_segs)
393{
394 if (iov_iter_is_bvec(iter))
395 return 0;
396 return iov_iter_npages(iter, max_segs);
397}
398
399/**
400 * bio_iov_bounce_nr_vecs - calculate number of bvecs for a bounce bio
401 * @iter: iter to bounce from
402 * @op: REQ_OP_* for the bio
403 *
404 * Calculates how many bvecs are needed for the next bio to bounce from/to
405 * @iter.
406 */
407static inline unsigned short
408bio_iov_bounce_nr_vecs(struct iov_iter *iter, blk_opf_t op)
409{
410 /*
411 * We still need to bounce bvec iters, so don't special case them
412 * here unlike in bio_iov_vecs_to_alloc.
413 *
414 * For reads we need to use a vector for the bounce buffer, account
415 * for that here.
416 */
417 if (op_is_write(op))
418 return iov_iter_npages(iter, BIO_MAX_VECS);
419 return iov_iter_npages(iter, BIO_MAX_VECS - 1) + 1;
420}
421
422struct request_queue;
423
424void bio_init(struct bio *bio, struct block_device *bdev, struct bio_vec *table,
425 unsigned short max_vecs, blk_opf_t opf);
426static inline void bio_init_inline(struct bio *bio, struct block_device *bdev,
427 unsigned short max_vecs, blk_opf_t opf)
428{
429 bio_init(bio, bdev, bio_inline_vecs(bio), max_vecs, opf);
430}
431extern void bio_uninit(struct bio *);
432void bio_reset(struct bio *bio, struct block_device *bdev, blk_opf_t opf);
433void bio_reuse(struct bio *bio, blk_opf_t opf);
434void bio_chain(struct bio *, struct bio *);
435void bio_await(struct bio *bio, void *priv,
436 void (*submit)(struct bio *bio, void *priv));
437
438int __must_check bio_add_page(struct bio *bio, struct page *page, unsigned len,
439 unsigned off);
440bool __must_check bio_add_folio(struct bio *bio, struct folio *folio,
441 size_t len, size_t off);
442void __bio_add_page(struct bio *bio, struct page *page,
443 unsigned int len, unsigned int off);
444void bio_add_folio_nofail(struct bio *bio, struct folio *folio, size_t len,
445 size_t off);
446void bio_add_virt_nofail(struct bio *bio, void *vaddr, unsigned len);
447
448/**
449 * bio_add_max_vecs - number of bio_vecs needed to add data to a bio
450 * @kaddr: kernel virtual address to add
451 * @len: length in bytes to add
452 *
453 * Calculate how many bio_vecs need to be allocated to add the kernel virtual
454 * address range in [@kaddr:@len] in the worse case.
455 */
456static inline unsigned int bio_add_max_vecs(void *kaddr, unsigned int len)
457{
458 if (is_vmalloc_addr(kaddr))
459 return DIV_ROUND_UP(offset_in_page(kaddr) + len, PAGE_SIZE);
460 return 1;
461}
462
463unsigned int bio_add_vmalloc_chunk(struct bio *bio, void *vaddr, unsigned len);
464bool bio_add_vmalloc(struct bio *bio, void *vaddr, unsigned int len);
465
466int submit_bio_wait(struct bio *bio);
467int bdev_rw_virt(struct block_device *bdev, sector_t sector, void *data,
468 size_t len, enum req_op op);
469
470int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter,
471 unsigned len_align_mask);
472
473void bio_iov_bvec_set(struct bio *bio, const struct iov_iter *iter);
474void __bio_release_pages(struct bio *bio, bool mark_dirty);
475extern void bio_set_pages_dirty(struct bio *bio);
476extern void bio_check_pages_dirty(struct bio *bio);
477
478int bio_iov_iter_bounce(struct bio *bio, struct iov_iter *iter, size_t maxlen);
479void bio_iov_iter_unbounce(struct bio *bio, bool is_error, bool mark_dirty);
480
481extern void bio_copy_data_iter(struct bio *dst, struct bvec_iter *dst_iter,
482 struct bio *src, struct bvec_iter *src_iter);
483extern void bio_copy_data(struct bio *dst, struct bio *src);
484extern void bio_free_pages(struct bio *bio);
485void guard_bio_eod(struct bio *bio);
486void zero_fill_bio_iter(struct bio *bio, struct bvec_iter iter);
487
488static inline void zero_fill_bio(struct bio *bio)
489{
490 zero_fill_bio_iter(bio, bio->bi_iter);
491}
492
493static inline void bio_release_pages(struct bio *bio, bool mark_dirty)
494{
495 if (bio_flagged(bio, BIO_PAGE_PINNED))
496 __bio_release_pages(bio, mark_dirty);
497}
498
499#define bio_dev(bio) \
500 disk_devt((bio)->bi_bdev->bd_disk)
501
502#ifdef CONFIG_BLK_CGROUP
503void bio_associate_blkg(struct bio *bio);
504void bio_associate_blkg_from_css(struct bio *bio,
505 struct cgroup_subsys_state *css);
506void bio_clone_blkg_association(struct bio *dst, struct bio *src);
507void blkcg_punt_bio_submit(struct bio *bio);
508#else /* CONFIG_BLK_CGROUP */
509static inline void bio_associate_blkg(struct bio *bio) { }
510static inline void bio_associate_blkg_from_css(struct bio *bio,
511 struct cgroup_subsys_state *css)
512{ }
513static inline void bio_clone_blkg_association(struct bio *dst,
514 struct bio *src) { }
515static inline void blkcg_punt_bio_submit(struct bio *bio)
516{
517 submit_bio(bio);
518}
519#endif /* CONFIG_BLK_CGROUP */
520
521static inline void bio_set_dev(struct bio *bio, struct block_device *bdev)
522{
523 bio_clear_flag(bio, BIO_REMAPPED);
524 if (bio->bi_bdev != bdev)
525 bio_clear_flag(bio, BIO_BPS_THROTTLED);
526 bio->bi_bdev = bdev;
527 bio_associate_blkg(bio);
528}
529
530/*
531 * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
532 *
533 * A bio_list anchors a singly-linked list of bios chained through the bi_next
534 * member of the bio. The bio_list also caches the last list member to allow
535 * fast access to the tail.
536 */
537struct bio_list {
538 struct bio *head;
539 struct bio *tail;
540};
541
542static inline int bio_list_empty(const struct bio_list *bl)
543{
544 return bl->head == NULL;
545}
546
547static inline void bio_list_init(struct bio_list *bl)
548{
549 bl->head = bl->tail = NULL;
550}
551
552#define BIO_EMPTY_LIST { NULL, NULL }
553
554#define bio_list_for_each(bio, bl) \
555 for (bio = (bl)->head; bio; bio = bio->bi_next)
556
557static inline unsigned bio_list_size(const struct bio_list *bl)
558{
559 unsigned sz = 0;
560 struct bio *bio;
561
562 bio_list_for_each(bio, bl)
563 sz++;
564
565 return sz;
566}
567
568static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
569{
570 bio->bi_next = NULL;
571
572 if (bl->tail)
573 bl->tail->bi_next = bio;
574 else
575 bl->head = bio;
576
577 bl->tail = bio;
578}
579
580static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
581{
582 bio->bi_next = bl->head;
583
584 bl->head = bio;
585
586 if (!bl->tail)
587 bl->tail = bio;
588}
589
590static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
591{
592 if (!bl2->head)
593 return;
594
595 if (bl->tail)
596 bl->tail->bi_next = bl2->head;
597 else
598 bl->head = bl2->head;
599
600 bl->tail = bl2->tail;
601}
602
603static inline void bio_list_merge_init(struct bio_list *bl,
604 struct bio_list *bl2)
605{
606 bio_list_merge(bl, bl2);
607 bio_list_init(bl2);
608}
609
610static inline void bio_list_merge_head(struct bio_list *bl,
611 struct bio_list *bl2)
612{
613 if (!bl2->head)
614 return;
615
616 if (bl->head)
617 bl2->tail->bi_next = bl->head;
618 else
619 bl->tail = bl2->tail;
620
621 bl->head = bl2->head;
622}
623
624static inline struct bio *bio_list_peek(struct bio_list *bl)
625{
626 return bl->head;
627}
628
629static inline struct bio *bio_list_pop(struct bio_list *bl)
630{
631 struct bio *bio = bl->head;
632
633 if (bio) {
634 bl->head = bl->head->bi_next;
635 if (!bl->head)
636 bl->tail = NULL;
637
638 bio->bi_next = NULL;
639 }
640
641 return bio;
642}
643
644static inline struct bio *bio_list_get(struct bio_list *bl)
645{
646 struct bio *bio = bl->head;
647
648 bl->head = bl->tail = NULL;
649
650 return bio;
651}
652
653/*
654 * Increment chain count for the bio. Make sure the CHAIN flag update
655 * is visible before the raised count.
656 */
657static inline void bio_inc_remaining(struct bio *bio)
658{
659 bio_set_flag(bio, BIO_CHAIN);
660 smp_mb__before_atomic();
661 atomic_inc(&bio->__bi_remaining);
662}
663
664/*
665 * bio_set is used to allow other portions of the IO system to
666 * allocate their own private memory pools for bio and iovec structures.
667 * These memory pools in turn all allocate from the bio_slab
668 * and the bvec_slabs[].
669 */
670#define BIO_POOL_SIZE 2
671
672struct bio_set {
673 struct kmem_cache *bio_slab;
674 unsigned int front_pad;
675
676 /*
677 * per-cpu bio alloc cache
678 */
679 struct bio_alloc_cache __percpu *cache;
680
681 mempool_t bio_pool;
682 mempool_t bvec_pool;
683
684 unsigned int back_pad;
685 /*
686 * Deadlock avoidance for stacking block drivers: see comments in
687 * bio_alloc_bioset() for details
688 */
689 spinlock_t rescue_lock;
690 struct bio_list rescue_list;
691 struct work_struct rescue_work;
692 struct workqueue_struct *rescue_workqueue;
693
694 /*
695 * Hot un-plug notifier for the per-cpu cache, if used
696 */
697 struct hlist_node cpuhp_dead;
698};
699
700static inline bool bioset_initialized(struct bio_set *bs)
701{
702 return bs->bio_slab != NULL;
703}
704
705/*
706 * Mark a bio as polled. Note that for async polled IO, the caller must
707 * expect -EWOULDBLOCK if we cannot allocate a request (or other resources).
708 * We cannot block waiting for requests on polled IO, as those completions
709 * must be found by the caller. This is different than IRQ driven IO, where
710 * it's safe to wait for IO to complete.
711 */
712static inline void bio_set_polled(struct bio *bio, struct kiocb *kiocb)
713{
714 bio->bi_opf |= REQ_POLLED;
715 if (kiocb->ki_flags & IOCB_NOWAIT)
716 bio->bi_opf |= REQ_NOWAIT;
717}
718
719static inline void bio_clear_polled(struct bio *bio)
720{
721 bio->bi_opf &= ~REQ_POLLED;
722}
723
724/**
725 * bio_is_zone_append - is this a zone append bio?
726 * @bio: bio to check
727 *
728 * Check if @bio is a zone append operation. Core block layer code and end_io
729 * handlers must use this instead of an open coded REQ_OP_ZONE_APPEND check
730 * because the block layer can rewrite REQ_OP_ZONE_APPEND to REQ_OP_WRITE if
731 * it is not natively supported.
732 */
733static inline bool bio_is_zone_append(struct bio *bio)
734{
735 if (!IS_ENABLED(CONFIG_BLK_DEV_ZONED))
736 return false;
737 return bio_op(bio) == REQ_OP_ZONE_APPEND ||
738 bio_flagged(bio, BIO_EMULATES_ZONE_APPEND);
739}
740
741struct bio *blk_next_bio(struct bio *bio, struct block_device *bdev,
742 unsigned int nr_pages, blk_opf_t opf, gfp_t gfp);
743struct bio *bio_chain_and_submit(struct bio *prev, struct bio *new);
744
745struct bio *blk_alloc_discard_bio(struct block_device *bdev,
746 sector_t *sector, sector_t *nr_sects, gfp_t gfp_mask);
747
748#endif /* __LINUX_BIO_H */