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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/highmem.h>
9#include <linux/mempool.h>
10#include <linux/ioprio.h>
11/* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */
12#include <linux/blk_types.h>
13
14#define BIO_DEBUG
15
16#ifdef BIO_DEBUG
17#define BIO_BUG_ON BUG_ON
18#else
19#define BIO_BUG_ON
20#endif
21
22#define BIO_MAX_PAGES 256
23
24#define bio_prio(bio) (bio)->bi_ioprio
25#define bio_set_prio(bio, prio) ((bio)->bi_ioprio = prio)
26
27#define bio_iter_iovec(bio, iter) \
28 bvec_iter_bvec((bio)->bi_io_vec, (iter))
29
30#define bio_iter_page(bio, iter) \
31 bvec_iter_page((bio)->bi_io_vec, (iter))
32#define bio_iter_len(bio, iter) \
33 bvec_iter_len((bio)->bi_io_vec, (iter))
34#define bio_iter_offset(bio, iter) \
35 bvec_iter_offset((bio)->bi_io_vec, (iter))
36
37#define bio_page(bio) bio_iter_page((bio), (bio)->bi_iter)
38#define bio_offset(bio) bio_iter_offset((bio), (bio)->bi_iter)
39#define bio_iovec(bio) bio_iter_iovec((bio), (bio)->bi_iter)
40
41#define bio_multiple_segments(bio) \
42 ((bio)->bi_iter.bi_size != bio_iovec(bio).bv_len)
43
44#define bvec_iter_sectors(iter) ((iter).bi_size >> 9)
45#define bvec_iter_end_sector(iter) ((iter).bi_sector + bvec_iter_sectors((iter)))
46
47#define bio_sectors(bio) bvec_iter_sectors((bio)->bi_iter)
48#define bio_end_sector(bio) bvec_iter_end_sector((bio)->bi_iter)
49
50/*
51 * Return the data direction, READ or WRITE.
52 */
53#define bio_data_dir(bio) \
54 (op_is_write(bio_op(bio)) ? WRITE : READ)
55
56/*
57 * Check whether this bio carries any data or not. A NULL bio is allowed.
58 */
59static inline bool bio_has_data(struct bio *bio)
60{
61 if (bio &&
62 bio->bi_iter.bi_size &&
63 bio_op(bio) != REQ_OP_DISCARD &&
64 bio_op(bio) != REQ_OP_SECURE_ERASE &&
65 bio_op(bio) != REQ_OP_WRITE_ZEROES)
66 return true;
67
68 return false;
69}
70
71static inline bool bio_no_advance_iter(const struct bio *bio)
72{
73 return bio_op(bio) == REQ_OP_DISCARD ||
74 bio_op(bio) == REQ_OP_SECURE_ERASE ||
75 bio_op(bio) == REQ_OP_WRITE_SAME ||
76 bio_op(bio) == REQ_OP_WRITE_ZEROES;
77}
78
79static inline bool bio_mergeable(struct bio *bio)
80{
81 if (bio->bi_opf & REQ_NOMERGE_FLAGS)
82 return false;
83
84 return true;
85}
86
87static inline unsigned int bio_cur_bytes(struct bio *bio)
88{
89 if (bio_has_data(bio))
90 return bio_iovec(bio).bv_len;
91 else /* dataless requests such as discard */
92 return bio->bi_iter.bi_size;
93}
94
95static inline void *bio_data(struct bio *bio)
96{
97 if (bio_has_data(bio))
98 return page_address(bio_page(bio)) + bio_offset(bio);
99
100 return NULL;
101}
102
103/**
104 * bio_full - check if the bio is full
105 * @bio: bio to check
106 * @len: length of one segment to be added
107 *
108 * Return true if @bio is full and one segment with @len bytes can't be
109 * added to the bio, otherwise return false
110 */
111static inline bool bio_full(struct bio *bio, unsigned len)
112{
113 if (bio->bi_vcnt >= bio->bi_max_vecs)
114 return true;
115
116 if (bio->bi_iter.bi_size > UINT_MAX - len)
117 return true;
118
119 return false;
120}
121
122static inline bool bio_next_segment(const struct bio *bio,
123 struct bvec_iter_all *iter)
124{
125 if (iter->idx >= bio->bi_vcnt)
126 return false;
127
128 bvec_advance(&bio->bi_io_vec[iter->idx], iter);
129 return true;
130}
131
132/*
133 * drivers should _never_ use the all version - the bio may have been split
134 * before it got to the driver and the driver won't own all of it
135 */
136#define bio_for_each_segment_all(bvl, bio, iter) \
137 for (bvl = bvec_init_iter_all(&iter); bio_next_segment((bio), &iter); )
138
139static inline void bio_advance_iter(const struct bio *bio,
140 struct bvec_iter *iter, unsigned int bytes)
141{
142 iter->bi_sector += bytes >> 9;
143
144 if (bio_no_advance_iter(bio))
145 iter->bi_size -= bytes;
146 else
147 bvec_iter_advance(bio->bi_io_vec, iter, bytes);
148 /* TODO: It is reasonable to complete bio with error here. */
149}
150
151#define __bio_for_each_segment(bvl, bio, iter, start) \
152 for (iter = (start); \
153 (iter).bi_size && \
154 ((bvl = bio_iter_iovec((bio), (iter))), 1); \
155 bio_advance_iter((bio), &(iter), (bvl).bv_len))
156
157#define bio_for_each_segment(bvl, bio, iter) \
158 __bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter)
159
160#define __bio_for_each_bvec(bvl, bio, iter, start) \
161 for (iter = (start); \
162 (iter).bi_size && \
163 ((bvl = mp_bvec_iter_bvec((bio)->bi_io_vec, (iter))), 1); \
164 bio_advance_iter((bio), &(iter), (bvl).bv_len))
165
166/* iterate over multi-page bvec */
167#define bio_for_each_bvec(bvl, bio, iter) \
168 __bio_for_each_bvec(bvl, bio, iter, (bio)->bi_iter)
169
170/*
171 * Iterate over all multi-page bvecs. Drivers shouldn't use this version for the
172 * same reasons as bio_for_each_segment_all().
173 */
174#define bio_for_each_bvec_all(bvl, bio, i) \
175 for (i = 0, bvl = bio_first_bvec_all(bio); \
176 i < (bio)->bi_vcnt; i++, bvl++) \
177
178#define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)
179
180static inline unsigned bio_segments(struct bio *bio)
181{
182 unsigned segs = 0;
183 struct bio_vec bv;
184 struct bvec_iter iter;
185
186 /*
187 * We special case discard/write same/write zeroes, because they
188 * interpret bi_size differently:
189 */
190
191 switch (bio_op(bio)) {
192 case REQ_OP_DISCARD:
193 case REQ_OP_SECURE_ERASE:
194 case REQ_OP_WRITE_ZEROES:
195 return 0;
196 case REQ_OP_WRITE_SAME:
197 return 1;
198 default:
199 break;
200 }
201
202 bio_for_each_segment(bv, bio, iter)
203 segs++;
204
205 return segs;
206}
207
208/*
209 * get a reference to a bio, so it won't disappear. the intended use is
210 * something like:
211 *
212 * bio_get(bio);
213 * submit_bio(rw, bio);
214 * if (bio->bi_flags ...)
215 * do_something
216 * bio_put(bio);
217 *
218 * without the bio_get(), it could potentially complete I/O before submit_bio
219 * returns. and then bio would be freed memory when if (bio->bi_flags ...)
220 * runs
221 */
222static inline void bio_get(struct bio *bio)
223{
224 bio->bi_flags |= (1 << BIO_REFFED);
225 smp_mb__before_atomic();
226 atomic_inc(&bio->__bi_cnt);
227}
228
229static inline void bio_cnt_set(struct bio *bio, unsigned int count)
230{
231 if (count != 1) {
232 bio->bi_flags |= (1 << BIO_REFFED);
233 smp_mb();
234 }
235 atomic_set(&bio->__bi_cnt, count);
236}
237
238static inline bool bio_flagged(struct bio *bio, unsigned int bit)
239{
240 return (bio->bi_flags & (1U << bit)) != 0;
241}
242
243static inline void bio_set_flag(struct bio *bio, unsigned int bit)
244{
245 bio->bi_flags |= (1U << bit);
246}
247
248static inline void bio_clear_flag(struct bio *bio, unsigned int bit)
249{
250 bio->bi_flags &= ~(1U << bit);
251}
252
253static inline void bio_get_first_bvec(struct bio *bio, struct bio_vec *bv)
254{
255 *bv = bio_iovec(bio);
256}
257
258static inline void bio_get_last_bvec(struct bio *bio, struct bio_vec *bv)
259{
260 struct bvec_iter iter = bio->bi_iter;
261 int idx;
262
263 if (unlikely(!bio_multiple_segments(bio))) {
264 *bv = bio_iovec(bio);
265 return;
266 }
267
268 bio_advance_iter(bio, &iter, iter.bi_size);
269
270 if (!iter.bi_bvec_done)
271 idx = iter.bi_idx - 1;
272 else /* in the middle of bvec */
273 idx = iter.bi_idx;
274
275 *bv = bio->bi_io_vec[idx];
276
277 /*
278 * iter.bi_bvec_done records actual length of the last bvec
279 * if this bio ends in the middle of one io vector
280 */
281 if (iter.bi_bvec_done)
282 bv->bv_len = iter.bi_bvec_done;
283}
284
285static inline struct bio_vec *bio_first_bvec_all(struct bio *bio)
286{
287 WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
288 return bio->bi_io_vec;
289}
290
291static inline struct page *bio_first_page_all(struct bio *bio)
292{
293 return bio_first_bvec_all(bio)->bv_page;
294}
295
296static inline struct bio_vec *bio_last_bvec_all(struct bio *bio)
297{
298 WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
299 return &bio->bi_io_vec[bio->bi_vcnt - 1];
300}
301
302enum bip_flags {
303 BIP_BLOCK_INTEGRITY = 1 << 0, /* block layer owns integrity data */
304 BIP_MAPPED_INTEGRITY = 1 << 1, /* ref tag has been remapped */
305 BIP_CTRL_NOCHECK = 1 << 2, /* disable HBA integrity checking */
306 BIP_DISK_NOCHECK = 1 << 3, /* disable disk integrity checking */
307 BIP_IP_CHECKSUM = 1 << 4, /* IP checksum */
308};
309
310/*
311 * bio integrity payload
312 */
313struct bio_integrity_payload {
314 struct bio *bip_bio; /* parent bio */
315
316 struct bvec_iter bip_iter;
317
318 unsigned short bip_slab; /* slab the bip came from */
319 unsigned short bip_vcnt; /* # of integrity bio_vecs */
320 unsigned short bip_max_vcnt; /* integrity bio_vec slots */
321 unsigned short bip_flags; /* control flags */
322
323 struct bvec_iter bio_iter; /* for rewinding parent bio */
324
325 struct work_struct bip_work; /* I/O completion */
326
327 struct bio_vec *bip_vec;
328 struct bio_vec bip_inline_vecs[];/* embedded bvec array */
329};
330
331#if defined(CONFIG_BLK_DEV_INTEGRITY)
332
333static inline struct bio_integrity_payload *bio_integrity(struct bio *bio)
334{
335 if (bio->bi_opf & REQ_INTEGRITY)
336 return bio->bi_integrity;
337
338 return NULL;
339}
340
341static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
342{
343 struct bio_integrity_payload *bip = bio_integrity(bio);
344
345 if (bip)
346 return bip->bip_flags & flag;
347
348 return false;
349}
350
351static inline sector_t bip_get_seed(struct bio_integrity_payload *bip)
352{
353 return bip->bip_iter.bi_sector;
354}
355
356static inline void bip_set_seed(struct bio_integrity_payload *bip,
357 sector_t seed)
358{
359 bip->bip_iter.bi_sector = seed;
360}
361
362#endif /* CONFIG_BLK_DEV_INTEGRITY */
363
364extern void bio_trim(struct bio *bio, int offset, int size);
365extern struct bio *bio_split(struct bio *bio, int sectors,
366 gfp_t gfp, struct bio_set *bs);
367
368/**
369 * bio_next_split - get next @sectors from a bio, splitting if necessary
370 * @bio: bio to split
371 * @sectors: number of sectors to split from the front of @bio
372 * @gfp: gfp mask
373 * @bs: bio set to allocate from
374 *
375 * Returns a bio representing the next @sectors of @bio - if the bio is smaller
376 * than @sectors, returns the original bio unchanged.
377 */
378static inline struct bio *bio_next_split(struct bio *bio, int sectors,
379 gfp_t gfp, struct bio_set *bs)
380{
381 if (sectors >= bio_sectors(bio))
382 return bio;
383
384 return bio_split(bio, sectors, gfp, bs);
385}
386
387enum {
388 BIOSET_NEED_BVECS = BIT(0),
389 BIOSET_NEED_RESCUER = BIT(1),
390};
391extern int bioset_init(struct bio_set *, unsigned int, unsigned int, int flags);
392extern void bioset_exit(struct bio_set *);
393extern int biovec_init_pool(mempool_t *pool, int pool_entries);
394extern int bioset_init_from_src(struct bio_set *bs, struct bio_set *src);
395
396extern struct bio *bio_alloc_bioset(gfp_t, unsigned int, struct bio_set *);
397extern void bio_put(struct bio *);
398
399extern void __bio_clone_fast(struct bio *, struct bio *);
400extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *);
401
402extern struct bio_set fs_bio_set;
403
404static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
405{
406 return bio_alloc_bioset(gfp_mask, nr_iovecs, &fs_bio_set);
407}
408
409static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
410{
411 return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
412}
413
414extern blk_qc_t submit_bio(struct bio *);
415
416extern void bio_endio(struct bio *);
417
418static inline void bio_io_error(struct bio *bio)
419{
420 bio->bi_status = BLK_STS_IOERR;
421 bio_endio(bio);
422}
423
424static inline void bio_wouldblock_error(struct bio *bio)
425{
426 bio_set_flag(bio, BIO_QUIET);
427 bio->bi_status = BLK_STS_AGAIN;
428 bio_endio(bio);
429}
430
431struct request_queue;
432
433extern int submit_bio_wait(struct bio *bio);
434extern void bio_advance(struct bio *, unsigned);
435
436extern void bio_init(struct bio *bio, struct bio_vec *table,
437 unsigned short max_vecs);
438extern void bio_uninit(struct bio *);
439extern void bio_reset(struct bio *);
440void bio_chain(struct bio *, struct bio *);
441
442extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
443extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
444 unsigned int, unsigned int);
445bool __bio_try_merge_page(struct bio *bio, struct page *page,
446 unsigned int len, unsigned int off, bool *same_page);
447void __bio_add_page(struct bio *bio, struct page *page,
448 unsigned int len, unsigned int off);
449int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter);
450void bio_release_pages(struct bio *bio, bool mark_dirty);
451extern void bio_set_pages_dirty(struct bio *bio);
452extern void bio_check_pages_dirty(struct bio *bio);
453
454extern void bio_copy_data_iter(struct bio *dst, struct bvec_iter *dst_iter,
455 struct bio *src, struct bvec_iter *src_iter);
456extern void bio_copy_data(struct bio *dst, struct bio *src);
457extern void bio_list_copy_data(struct bio *dst, struct bio *src);
458extern void bio_free_pages(struct bio *bio);
459void zero_fill_bio_iter(struct bio *bio, struct bvec_iter iter);
460void bio_truncate(struct bio *bio, unsigned new_size);
461void guard_bio_eod(struct bio *bio);
462
463static inline void zero_fill_bio(struct bio *bio)
464{
465 zero_fill_bio_iter(bio, bio->bi_iter);
466}
467
468extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *);
469extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int);
470extern unsigned int bvec_nr_vecs(unsigned short idx);
471extern const char *bio_devname(struct bio *bio, char *buffer);
472
473#define bio_set_dev(bio, bdev) \
474do { \
475 if ((bio)->bi_disk != (bdev)->bd_disk) \
476 bio_clear_flag(bio, BIO_THROTTLED);\
477 (bio)->bi_disk = (bdev)->bd_disk; \
478 (bio)->bi_partno = (bdev)->bd_partno; \
479 bio_associate_blkg(bio); \
480} while (0)
481
482#define bio_copy_dev(dst, src) \
483do { \
484 (dst)->bi_disk = (src)->bi_disk; \
485 (dst)->bi_partno = (src)->bi_partno; \
486 bio_clone_blkg_association(dst, src); \
487} while (0)
488
489#define bio_dev(bio) \
490 disk_devt((bio)->bi_disk)
491
492#ifdef CONFIG_BLK_CGROUP
493void bio_associate_blkg(struct bio *bio);
494void bio_associate_blkg_from_css(struct bio *bio,
495 struct cgroup_subsys_state *css);
496void bio_clone_blkg_association(struct bio *dst, struct bio *src);
497#else /* CONFIG_BLK_CGROUP */
498static inline void bio_associate_blkg(struct bio *bio) { }
499static inline void bio_associate_blkg_from_css(struct bio *bio,
500 struct cgroup_subsys_state *css)
501{ }
502static inline void bio_clone_blkg_association(struct bio *dst,
503 struct bio *src) { }
504#endif /* CONFIG_BLK_CGROUP */
505
506#ifdef CONFIG_HIGHMEM
507/*
508 * remember never ever reenable interrupts between a bvec_kmap_irq and
509 * bvec_kunmap_irq!
510 */
511static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
512{
513 unsigned long addr;
514
515 /*
516 * might not be a highmem page, but the preempt/irq count
517 * balancing is a lot nicer this way
518 */
519 local_irq_save(*flags);
520 addr = (unsigned long) kmap_atomic(bvec->bv_page);
521
522 BUG_ON(addr & ~PAGE_MASK);
523
524 return (char *) addr + bvec->bv_offset;
525}
526
527static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
528{
529 unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
530
531 kunmap_atomic((void *) ptr);
532 local_irq_restore(*flags);
533}
534
535#else
536static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
537{
538 return page_address(bvec->bv_page) + bvec->bv_offset;
539}
540
541static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
542{
543 *flags = 0;
544}
545#endif
546
547/*
548 * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
549 *
550 * A bio_list anchors a singly-linked list of bios chained through the bi_next
551 * member of the bio. The bio_list also caches the last list member to allow
552 * fast access to the tail.
553 */
554struct bio_list {
555 struct bio *head;
556 struct bio *tail;
557};
558
559static inline int bio_list_empty(const struct bio_list *bl)
560{
561 return bl->head == NULL;
562}
563
564static inline void bio_list_init(struct bio_list *bl)
565{
566 bl->head = bl->tail = NULL;
567}
568
569#define BIO_EMPTY_LIST { NULL, NULL }
570
571#define bio_list_for_each(bio, bl) \
572 for (bio = (bl)->head; bio; bio = bio->bi_next)
573
574static inline unsigned bio_list_size(const struct bio_list *bl)
575{
576 unsigned sz = 0;
577 struct bio *bio;
578
579 bio_list_for_each(bio, bl)
580 sz++;
581
582 return sz;
583}
584
585static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
586{
587 bio->bi_next = NULL;
588
589 if (bl->tail)
590 bl->tail->bi_next = bio;
591 else
592 bl->head = bio;
593
594 bl->tail = bio;
595}
596
597static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
598{
599 bio->bi_next = bl->head;
600
601 bl->head = bio;
602
603 if (!bl->tail)
604 bl->tail = bio;
605}
606
607static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
608{
609 if (!bl2->head)
610 return;
611
612 if (bl->tail)
613 bl->tail->bi_next = bl2->head;
614 else
615 bl->head = bl2->head;
616
617 bl->tail = bl2->tail;
618}
619
620static inline void bio_list_merge_head(struct bio_list *bl,
621 struct bio_list *bl2)
622{
623 if (!bl2->head)
624 return;
625
626 if (bl->head)
627 bl2->tail->bi_next = bl->head;
628 else
629 bl->tail = bl2->tail;
630
631 bl->head = bl2->head;
632}
633
634static inline struct bio *bio_list_peek(struct bio_list *bl)
635{
636 return bl->head;
637}
638
639static inline struct bio *bio_list_pop(struct bio_list *bl)
640{
641 struct bio *bio = bl->head;
642
643 if (bio) {
644 bl->head = bl->head->bi_next;
645 if (!bl->head)
646 bl->tail = NULL;
647
648 bio->bi_next = NULL;
649 }
650
651 return bio;
652}
653
654static inline struct bio *bio_list_get(struct bio_list *bl)
655{
656 struct bio *bio = bl->head;
657
658 bl->head = bl->tail = NULL;
659
660 return bio;
661}
662
663/*
664 * Increment chain count for the bio. Make sure the CHAIN flag update
665 * is visible before the raised count.
666 */
667static inline void bio_inc_remaining(struct bio *bio)
668{
669 bio_set_flag(bio, BIO_CHAIN);
670 smp_mb__before_atomic();
671 atomic_inc(&bio->__bi_remaining);
672}
673
674/*
675 * bio_set is used to allow other portions of the IO system to
676 * allocate their own private memory pools for bio and iovec structures.
677 * These memory pools in turn all allocate from the bio_slab
678 * and the bvec_slabs[].
679 */
680#define BIO_POOL_SIZE 2
681
682struct bio_set {
683 struct kmem_cache *bio_slab;
684 unsigned int front_pad;
685
686 mempool_t bio_pool;
687 mempool_t bvec_pool;
688#if defined(CONFIG_BLK_DEV_INTEGRITY)
689 mempool_t bio_integrity_pool;
690 mempool_t bvec_integrity_pool;
691#endif
692
693 /*
694 * Deadlock avoidance for stacking block drivers: see comments in
695 * bio_alloc_bioset() for details
696 */
697 spinlock_t rescue_lock;
698 struct bio_list rescue_list;
699 struct work_struct rescue_work;
700 struct workqueue_struct *rescue_workqueue;
701};
702
703struct biovec_slab {
704 int nr_vecs;
705 char *name;
706 struct kmem_cache *slab;
707};
708
709static inline bool bioset_initialized(struct bio_set *bs)
710{
711 return bs->bio_slab != NULL;
712}
713
714/*
715 * a small number of entries is fine, not going to be performance critical.
716 * basically we just need to survive
717 */
718#define BIO_SPLIT_ENTRIES 2
719
720#if defined(CONFIG_BLK_DEV_INTEGRITY)
721
722#define bip_for_each_vec(bvl, bip, iter) \
723 for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
724
725#define bio_for_each_integrity_vec(_bvl, _bio, _iter) \
726 for_each_bio(_bio) \
727 bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
728
729extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
730extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
731extern bool bio_integrity_prep(struct bio *);
732extern void bio_integrity_advance(struct bio *, unsigned int);
733extern void bio_integrity_trim(struct bio *);
734extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t);
735extern int bioset_integrity_create(struct bio_set *, int);
736extern void bioset_integrity_free(struct bio_set *);
737extern void bio_integrity_init(void);
738
739#else /* CONFIG_BLK_DEV_INTEGRITY */
740
741static inline void *bio_integrity(struct bio *bio)
742{
743 return NULL;
744}
745
746static inline int bioset_integrity_create(struct bio_set *bs, int pool_size)
747{
748 return 0;
749}
750
751static inline void bioset_integrity_free (struct bio_set *bs)
752{
753 return;
754}
755
756static inline bool bio_integrity_prep(struct bio *bio)
757{
758 return true;
759}
760
761static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
762 gfp_t gfp_mask)
763{
764 return 0;
765}
766
767static inline void bio_integrity_advance(struct bio *bio,
768 unsigned int bytes_done)
769{
770 return;
771}
772
773static inline void bio_integrity_trim(struct bio *bio)
774{
775 return;
776}
777
778static inline void bio_integrity_init(void)
779{
780 return;
781}
782
783static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
784{
785 return false;
786}
787
788static inline void *bio_integrity_alloc(struct bio * bio, gfp_t gfp,
789 unsigned int nr)
790{
791 return ERR_PTR(-EINVAL);
792}
793
794static inline int bio_integrity_add_page(struct bio *bio, struct page *page,
795 unsigned int len, unsigned int offset)
796{
797 return 0;
798}
799
800#endif /* CONFIG_BLK_DEV_INTEGRITY */
801
802/*
803 * Mark a bio as polled. Note that for async polled IO, the caller must
804 * expect -EWOULDBLOCK if we cannot allocate a request (or other resources).
805 * We cannot block waiting for requests on polled IO, as those completions
806 * must be found by the caller. This is different than IRQ driven IO, where
807 * it's safe to wait for IO to complete.
808 */
809static inline void bio_set_polled(struct bio *bio, struct kiocb *kiocb)
810{
811 bio->bi_opf |= REQ_HIPRI;
812 if (!is_sync_kiocb(kiocb))
813 bio->bi_opf |= REQ_NOWAIT;
814}
815
816#endif /* __LINUX_BIO_H */
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/highmem.h>
9#include <linux/mempool.h>
10#include <linux/ioprio.h>
11
12#ifdef CONFIG_BLOCK
13/* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */
14#include <linux/blk_types.h>
15
16#define BIO_DEBUG
17
18#ifdef BIO_DEBUG
19#define BIO_BUG_ON BUG_ON
20#else
21#define BIO_BUG_ON
22#endif
23
24#define BIO_MAX_PAGES 256
25
26#define bio_prio(bio) (bio)->bi_ioprio
27#define bio_set_prio(bio, prio) ((bio)->bi_ioprio = prio)
28
29#define bio_iter_iovec(bio, iter) \
30 bvec_iter_bvec((bio)->bi_io_vec, (iter))
31
32#define bio_iter_page(bio, iter) \
33 bvec_iter_page((bio)->bi_io_vec, (iter))
34#define bio_iter_len(bio, iter) \
35 bvec_iter_len((bio)->bi_io_vec, (iter))
36#define bio_iter_offset(bio, iter) \
37 bvec_iter_offset((bio)->bi_io_vec, (iter))
38
39#define bio_page(bio) bio_iter_page((bio), (bio)->bi_iter)
40#define bio_offset(bio) bio_iter_offset((bio), (bio)->bi_iter)
41#define bio_iovec(bio) bio_iter_iovec((bio), (bio)->bi_iter)
42
43#define bio_multiple_segments(bio) \
44 ((bio)->bi_iter.bi_size != bio_iovec(bio).bv_len)
45
46#define bvec_iter_sectors(iter) ((iter).bi_size >> 9)
47#define bvec_iter_end_sector(iter) ((iter).bi_sector + bvec_iter_sectors((iter)))
48
49#define bio_sectors(bio) bvec_iter_sectors((bio)->bi_iter)
50#define bio_end_sector(bio) bvec_iter_end_sector((bio)->bi_iter)
51
52/*
53 * Return the data direction, READ or WRITE.
54 */
55#define bio_data_dir(bio) \
56 (op_is_write(bio_op(bio)) ? WRITE : READ)
57
58/*
59 * Check whether this bio carries any data or not. A NULL bio is allowed.
60 */
61static inline bool bio_has_data(struct bio *bio)
62{
63 if (bio &&
64 bio->bi_iter.bi_size &&
65 bio_op(bio) != REQ_OP_DISCARD &&
66 bio_op(bio) != REQ_OP_SECURE_ERASE &&
67 bio_op(bio) != REQ_OP_WRITE_ZEROES)
68 return true;
69
70 return false;
71}
72
73static inline bool bio_no_advance_iter(struct bio *bio)
74{
75 return bio_op(bio) == REQ_OP_DISCARD ||
76 bio_op(bio) == REQ_OP_SECURE_ERASE ||
77 bio_op(bio) == REQ_OP_WRITE_SAME ||
78 bio_op(bio) == REQ_OP_WRITE_ZEROES;
79}
80
81static inline bool bio_mergeable(struct bio *bio)
82{
83 if (bio->bi_opf & REQ_NOMERGE_FLAGS)
84 return false;
85
86 return true;
87}
88
89static inline unsigned int bio_cur_bytes(struct bio *bio)
90{
91 if (bio_has_data(bio))
92 return bio_iovec(bio).bv_len;
93 else /* dataless requests such as discard */
94 return bio->bi_iter.bi_size;
95}
96
97static inline void *bio_data(struct bio *bio)
98{
99 if (bio_has_data(bio))
100 return page_address(bio_page(bio)) + bio_offset(bio);
101
102 return NULL;
103}
104
105/**
106 * bio_full - check if the bio is full
107 * @bio: bio to check
108 * @len: length of one segment to be added
109 *
110 * Return true if @bio is full and one segment with @len bytes can't be
111 * added to the bio, otherwise return false
112 */
113static inline bool bio_full(struct bio *bio, unsigned len)
114{
115 if (bio->bi_vcnt >= bio->bi_max_vecs)
116 return true;
117
118 if (bio->bi_iter.bi_size > UINT_MAX - len)
119 return true;
120
121 return false;
122}
123
124static inline bool bio_next_segment(const struct bio *bio,
125 struct bvec_iter_all *iter)
126{
127 if (iter->idx >= bio->bi_vcnt)
128 return false;
129
130 bvec_advance(&bio->bi_io_vec[iter->idx], iter);
131 return true;
132}
133
134/*
135 * drivers should _never_ use the all version - the bio may have been split
136 * before it got to the driver and the driver won't own all of it
137 */
138#define bio_for_each_segment_all(bvl, bio, iter) \
139 for (bvl = bvec_init_iter_all(&iter); bio_next_segment((bio), &iter); )
140
141static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter,
142 unsigned bytes)
143{
144 iter->bi_sector += bytes >> 9;
145
146 if (bio_no_advance_iter(bio))
147 iter->bi_size -= bytes;
148 else
149 bvec_iter_advance(bio->bi_io_vec, iter, bytes);
150 /* TODO: It is reasonable to complete bio with error here. */
151}
152
153#define __bio_for_each_segment(bvl, bio, iter, start) \
154 for (iter = (start); \
155 (iter).bi_size && \
156 ((bvl = bio_iter_iovec((bio), (iter))), 1); \
157 bio_advance_iter((bio), &(iter), (bvl).bv_len))
158
159#define bio_for_each_segment(bvl, bio, iter) \
160 __bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter)
161
162#define __bio_for_each_bvec(bvl, bio, iter, start) \
163 for (iter = (start); \
164 (iter).bi_size && \
165 ((bvl = mp_bvec_iter_bvec((bio)->bi_io_vec, (iter))), 1); \
166 bio_advance_iter((bio), &(iter), (bvl).bv_len))
167
168/* iterate over multi-page bvec */
169#define bio_for_each_bvec(bvl, bio, iter) \
170 __bio_for_each_bvec(bvl, bio, iter, (bio)->bi_iter)
171
172#define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)
173
174static inline unsigned bio_segments(struct bio *bio)
175{
176 unsigned segs = 0;
177 struct bio_vec bv;
178 struct bvec_iter iter;
179
180 /*
181 * We special case discard/write same/write zeroes, because they
182 * interpret bi_size differently:
183 */
184
185 switch (bio_op(bio)) {
186 case REQ_OP_DISCARD:
187 case REQ_OP_SECURE_ERASE:
188 case REQ_OP_WRITE_ZEROES:
189 return 0;
190 case REQ_OP_WRITE_SAME:
191 return 1;
192 default:
193 break;
194 }
195
196 bio_for_each_segment(bv, bio, iter)
197 segs++;
198
199 return segs;
200}
201
202/*
203 * get a reference to a bio, so it won't disappear. the intended use is
204 * something like:
205 *
206 * bio_get(bio);
207 * submit_bio(rw, bio);
208 * if (bio->bi_flags ...)
209 * do_something
210 * bio_put(bio);
211 *
212 * without the bio_get(), it could potentially complete I/O before submit_bio
213 * returns. and then bio would be freed memory when if (bio->bi_flags ...)
214 * runs
215 */
216static inline void bio_get(struct bio *bio)
217{
218 bio->bi_flags |= (1 << BIO_REFFED);
219 smp_mb__before_atomic();
220 atomic_inc(&bio->__bi_cnt);
221}
222
223static inline void bio_cnt_set(struct bio *bio, unsigned int count)
224{
225 if (count != 1) {
226 bio->bi_flags |= (1 << BIO_REFFED);
227 smp_mb();
228 }
229 atomic_set(&bio->__bi_cnt, count);
230}
231
232static inline bool bio_flagged(struct bio *bio, unsigned int bit)
233{
234 return (bio->bi_flags & (1U << bit)) != 0;
235}
236
237static inline void bio_set_flag(struct bio *bio, unsigned int bit)
238{
239 bio->bi_flags |= (1U << bit);
240}
241
242static inline void bio_clear_flag(struct bio *bio, unsigned int bit)
243{
244 bio->bi_flags &= ~(1U << bit);
245}
246
247static inline void bio_get_first_bvec(struct bio *bio, struct bio_vec *bv)
248{
249 *bv = bio_iovec(bio);
250}
251
252static inline void bio_get_last_bvec(struct bio *bio, struct bio_vec *bv)
253{
254 struct bvec_iter iter = bio->bi_iter;
255 int idx;
256
257 if (unlikely(!bio_multiple_segments(bio))) {
258 *bv = bio_iovec(bio);
259 return;
260 }
261
262 bio_advance_iter(bio, &iter, iter.bi_size);
263
264 if (!iter.bi_bvec_done)
265 idx = iter.bi_idx - 1;
266 else /* in the middle of bvec */
267 idx = iter.bi_idx;
268
269 *bv = bio->bi_io_vec[idx];
270
271 /*
272 * iter.bi_bvec_done records actual length of the last bvec
273 * if this bio ends in the middle of one io vector
274 */
275 if (iter.bi_bvec_done)
276 bv->bv_len = iter.bi_bvec_done;
277}
278
279static inline struct bio_vec *bio_first_bvec_all(struct bio *bio)
280{
281 WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
282 return bio->bi_io_vec;
283}
284
285static inline struct page *bio_first_page_all(struct bio *bio)
286{
287 return bio_first_bvec_all(bio)->bv_page;
288}
289
290static inline struct bio_vec *bio_last_bvec_all(struct bio *bio)
291{
292 WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
293 return &bio->bi_io_vec[bio->bi_vcnt - 1];
294}
295
296enum bip_flags {
297 BIP_BLOCK_INTEGRITY = 1 << 0, /* block layer owns integrity data */
298 BIP_MAPPED_INTEGRITY = 1 << 1, /* ref tag has been remapped */
299 BIP_CTRL_NOCHECK = 1 << 2, /* disable HBA integrity checking */
300 BIP_DISK_NOCHECK = 1 << 3, /* disable disk integrity checking */
301 BIP_IP_CHECKSUM = 1 << 4, /* IP checksum */
302};
303
304/*
305 * bio integrity payload
306 */
307struct bio_integrity_payload {
308 struct bio *bip_bio; /* parent bio */
309
310 struct bvec_iter bip_iter;
311
312 unsigned short bip_slab; /* slab the bip came from */
313 unsigned short bip_vcnt; /* # of integrity bio_vecs */
314 unsigned short bip_max_vcnt; /* integrity bio_vec slots */
315 unsigned short bip_flags; /* control flags */
316
317 struct bvec_iter bio_iter; /* for rewinding parent bio */
318
319 struct work_struct bip_work; /* I/O completion */
320
321 struct bio_vec *bip_vec;
322 struct bio_vec bip_inline_vecs[0];/* embedded bvec array */
323};
324
325#if defined(CONFIG_BLK_DEV_INTEGRITY)
326
327static inline struct bio_integrity_payload *bio_integrity(struct bio *bio)
328{
329 if (bio->bi_opf & REQ_INTEGRITY)
330 return bio->bi_integrity;
331
332 return NULL;
333}
334
335static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
336{
337 struct bio_integrity_payload *bip = bio_integrity(bio);
338
339 if (bip)
340 return bip->bip_flags & flag;
341
342 return false;
343}
344
345static inline sector_t bip_get_seed(struct bio_integrity_payload *bip)
346{
347 return bip->bip_iter.bi_sector;
348}
349
350static inline void bip_set_seed(struct bio_integrity_payload *bip,
351 sector_t seed)
352{
353 bip->bip_iter.bi_sector = seed;
354}
355
356#endif /* CONFIG_BLK_DEV_INTEGRITY */
357
358extern void bio_trim(struct bio *bio, int offset, int size);
359extern struct bio *bio_split(struct bio *bio, int sectors,
360 gfp_t gfp, struct bio_set *bs);
361
362/**
363 * bio_next_split - get next @sectors from a bio, splitting if necessary
364 * @bio: bio to split
365 * @sectors: number of sectors to split from the front of @bio
366 * @gfp: gfp mask
367 * @bs: bio set to allocate from
368 *
369 * Returns a bio representing the next @sectors of @bio - if the bio is smaller
370 * than @sectors, returns the original bio unchanged.
371 */
372static inline struct bio *bio_next_split(struct bio *bio, int sectors,
373 gfp_t gfp, struct bio_set *bs)
374{
375 if (sectors >= bio_sectors(bio))
376 return bio;
377
378 return bio_split(bio, sectors, gfp, bs);
379}
380
381enum {
382 BIOSET_NEED_BVECS = BIT(0),
383 BIOSET_NEED_RESCUER = BIT(1),
384};
385extern int bioset_init(struct bio_set *, unsigned int, unsigned int, int flags);
386extern void bioset_exit(struct bio_set *);
387extern int biovec_init_pool(mempool_t *pool, int pool_entries);
388extern int bioset_init_from_src(struct bio_set *bs, struct bio_set *src);
389
390extern struct bio *bio_alloc_bioset(gfp_t, unsigned int, struct bio_set *);
391extern void bio_put(struct bio *);
392
393extern void __bio_clone_fast(struct bio *, struct bio *);
394extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *);
395
396extern struct bio_set fs_bio_set;
397
398static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
399{
400 return bio_alloc_bioset(gfp_mask, nr_iovecs, &fs_bio_set);
401}
402
403static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
404{
405 return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
406}
407
408extern blk_qc_t submit_bio(struct bio *);
409
410extern void bio_endio(struct bio *);
411
412static inline void bio_io_error(struct bio *bio)
413{
414 bio->bi_status = BLK_STS_IOERR;
415 bio_endio(bio);
416}
417
418static inline void bio_wouldblock_error(struct bio *bio)
419{
420 bio->bi_status = BLK_STS_AGAIN;
421 bio_endio(bio);
422}
423
424struct request_queue;
425
426extern int submit_bio_wait(struct bio *bio);
427extern void bio_advance(struct bio *, unsigned);
428
429extern void bio_init(struct bio *bio, struct bio_vec *table,
430 unsigned short max_vecs);
431extern void bio_uninit(struct bio *);
432extern void bio_reset(struct bio *);
433void bio_chain(struct bio *, struct bio *);
434
435extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
436extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
437 unsigned int, unsigned int);
438bool __bio_try_merge_page(struct bio *bio, struct page *page,
439 unsigned int len, unsigned int off, bool *same_page);
440void __bio_add_page(struct bio *bio, struct page *page,
441 unsigned int len, unsigned int off);
442int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter);
443void bio_release_pages(struct bio *bio, bool mark_dirty);
444struct rq_map_data;
445extern struct bio *bio_map_user_iov(struct request_queue *,
446 struct iov_iter *, gfp_t);
447extern void bio_unmap_user(struct bio *);
448extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
449 gfp_t);
450extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
451 gfp_t, int);
452extern void bio_set_pages_dirty(struct bio *bio);
453extern void bio_check_pages_dirty(struct bio *bio);
454
455void generic_start_io_acct(struct request_queue *q, int op,
456 unsigned long sectors, struct hd_struct *part);
457void generic_end_io_acct(struct request_queue *q, int op,
458 struct hd_struct *part,
459 unsigned long start_time);
460
461extern void bio_copy_data_iter(struct bio *dst, struct bvec_iter *dst_iter,
462 struct bio *src, struct bvec_iter *src_iter);
463extern void bio_copy_data(struct bio *dst, struct bio *src);
464extern void bio_list_copy_data(struct bio *dst, struct bio *src);
465extern void bio_free_pages(struct bio *bio);
466
467extern struct bio *bio_copy_user_iov(struct request_queue *,
468 struct rq_map_data *,
469 struct iov_iter *,
470 gfp_t);
471extern int bio_uncopy_user(struct bio *);
472void zero_fill_bio_iter(struct bio *bio, struct bvec_iter iter);
473
474static inline void zero_fill_bio(struct bio *bio)
475{
476 zero_fill_bio_iter(bio, bio->bi_iter);
477}
478
479extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *);
480extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int);
481extern unsigned int bvec_nr_vecs(unsigned short idx);
482extern const char *bio_devname(struct bio *bio, char *buffer);
483
484#define bio_set_dev(bio, bdev) \
485do { \
486 if ((bio)->bi_disk != (bdev)->bd_disk) \
487 bio_clear_flag(bio, BIO_THROTTLED);\
488 (bio)->bi_disk = (bdev)->bd_disk; \
489 (bio)->bi_partno = (bdev)->bd_partno; \
490 bio_associate_blkg(bio); \
491} while (0)
492
493#define bio_copy_dev(dst, src) \
494do { \
495 (dst)->bi_disk = (src)->bi_disk; \
496 (dst)->bi_partno = (src)->bi_partno; \
497 bio_clone_blkg_association(dst, src); \
498} while (0)
499
500#define bio_dev(bio) \
501 disk_devt((bio)->bi_disk)
502
503#if defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP)
504void bio_associate_blkg_from_page(struct bio *bio, struct page *page);
505#else
506static inline void bio_associate_blkg_from_page(struct bio *bio,
507 struct page *page) { }
508#endif
509
510#ifdef CONFIG_BLK_CGROUP
511void bio_disassociate_blkg(struct bio *bio);
512void bio_associate_blkg(struct bio *bio);
513void bio_associate_blkg_from_css(struct bio *bio,
514 struct cgroup_subsys_state *css);
515void bio_clone_blkg_association(struct bio *dst, struct bio *src);
516#else /* CONFIG_BLK_CGROUP */
517static inline void bio_disassociate_blkg(struct bio *bio) { }
518static inline void bio_associate_blkg(struct bio *bio) { }
519static inline void bio_associate_blkg_from_css(struct bio *bio,
520 struct cgroup_subsys_state *css)
521{ }
522static inline void bio_clone_blkg_association(struct bio *dst,
523 struct bio *src) { }
524#endif /* CONFIG_BLK_CGROUP */
525
526#ifdef CONFIG_HIGHMEM
527/*
528 * remember never ever reenable interrupts between a bvec_kmap_irq and
529 * bvec_kunmap_irq!
530 */
531static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
532{
533 unsigned long addr;
534
535 /*
536 * might not be a highmem page, but the preempt/irq count
537 * balancing is a lot nicer this way
538 */
539 local_irq_save(*flags);
540 addr = (unsigned long) kmap_atomic(bvec->bv_page);
541
542 BUG_ON(addr & ~PAGE_MASK);
543
544 return (char *) addr + bvec->bv_offset;
545}
546
547static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
548{
549 unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
550
551 kunmap_atomic((void *) ptr);
552 local_irq_restore(*flags);
553}
554
555#else
556static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
557{
558 return page_address(bvec->bv_page) + bvec->bv_offset;
559}
560
561static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
562{
563 *flags = 0;
564}
565#endif
566
567/*
568 * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
569 *
570 * A bio_list anchors a singly-linked list of bios chained through the bi_next
571 * member of the bio. The bio_list also caches the last list member to allow
572 * fast access to the tail.
573 */
574struct bio_list {
575 struct bio *head;
576 struct bio *tail;
577};
578
579static inline int bio_list_empty(const struct bio_list *bl)
580{
581 return bl->head == NULL;
582}
583
584static inline void bio_list_init(struct bio_list *bl)
585{
586 bl->head = bl->tail = NULL;
587}
588
589#define BIO_EMPTY_LIST { NULL, NULL }
590
591#define bio_list_for_each(bio, bl) \
592 for (bio = (bl)->head; bio; bio = bio->bi_next)
593
594static inline unsigned bio_list_size(const struct bio_list *bl)
595{
596 unsigned sz = 0;
597 struct bio *bio;
598
599 bio_list_for_each(bio, bl)
600 sz++;
601
602 return sz;
603}
604
605static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
606{
607 bio->bi_next = NULL;
608
609 if (bl->tail)
610 bl->tail->bi_next = bio;
611 else
612 bl->head = bio;
613
614 bl->tail = bio;
615}
616
617static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
618{
619 bio->bi_next = bl->head;
620
621 bl->head = bio;
622
623 if (!bl->tail)
624 bl->tail = bio;
625}
626
627static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
628{
629 if (!bl2->head)
630 return;
631
632 if (bl->tail)
633 bl->tail->bi_next = bl2->head;
634 else
635 bl->head = bl2->head;
636
637 bl->tail = bl2->tail;
638}
639
640static inline void bio_list_merge_head(struct bio_list *bl,
641 struct bio_list *bl2)
642{
643 if (!bl2->head)
644 return;
645
646 if (bl->head)
647 bl2->tail->bi_next = bl->head;
648 else
649 bl->tail = bl2->tail;
650
651 bl->head = bl2->head;
652}
653
654static inline struct bio *bio_list_peek(struct bio_list *bl)
655{
656 return bl->head;
657}
658
659static inline struct bio *bio_list_pop(struct bio_list *bl)
660{
661 struct bio *bio = bl->head;
662
663 if (bio) {
664 bl->head = bl->head->bi_next;
665 if (!bl->head)
666 bl->tail = NULL;
667
668 bio->bi_next = NULL;
669 }
670
671 return bio;
672}
673
674static inline struct bio *bio_list_get(struct bio_list *bl)
675{
676 struct bio *bio = bl->head;
677
678 bl->head = bl->tail = NULL;
679
680 return bio;
681}
682
683/*
684 * Increment chain count for the bio. Make sure the CHAIN flag update
685 * is visible before the raised count.
686 */
687static inline void bio_inc_remaining(struct bio *bio)
688{
689 bio_set_flag(bio, BIO_CHAIN);
690 smp_mb__before_atomic();
691 atomic_inc(&bio->__bi_remaining);
692}
693
694/*
695 * bio_set is used to allow other portions of the IO system to
696 * allocate their own private memory pools for bio and iovec structures.
697 * These memory pools in turn all allocate from the bio_slab
698 * and the bvec_slabs[].
699 */
700#define BIO_POOL_SIZE 2
701
702struct bio_set {
703 struct kmem_cache *bio_slab;
704 unsigned int front_pad;
705
706 mempool_t bio_pool;
707 mempool_t bvec_pool;
708#if defined(CONFIG_BLK_DEV_INTEGRITY)
709 mempool_t bio_integrity_pool;
710 mempool_t bvec_integrity_pool;
711#endif
712
713 /*
714 * Deadlock avoidance for stacking block drivers: see comments in
715 * bio_alloc_bioset() for details
716 */
717 spinlock_t rescue_lock;
718 struct bio_list rescue_list;
719 struct work_struct rescue_work;
720 struct workqueue_struct *rescue_workqueue;
721};
722
723struct biovec_slab {
724 int nr_vecs;
725 char *name;
726 struct kmem_cache *slab;
727};
728
729static inline bool bioset_initialized(struct bio_set *bs)
730{
731 return bs->bio_slab != NULL;
732}
733
734/*
735 * a small number of entries is fine, not going to be performance critical.
736 * basically we just need to survive
737 */
738#define BIO_SPLIT_ENTRIES 2
739
740#if defined(CONFIG_BLK_DEV_INTEGRITY)
741
742#define bip_for_each_vec(bvl, bip, iter) \
743 for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
744
745#define bio_for_each_integrity_vec(_bvl, _bio, _iter) \
746 for_each_bio(_bio) \
747 bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
748
749extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
750extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
751extern bool bio_integrity_prep(struct bio *);
752extern void bio_integrity_advance(struct bio *, unsigned int);
753extern void bio_integrity_trim(struct bio *);
754extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t);
755extern int bioset_integrity_create(struct bio_set *, int);
756extern void bioset_integrity_free(struct bio_set *);
757extern void bio_integrity_init(void);
758
759#else /* CONFIG_BLK_DEV_INTEGRITY */
760
761static inline void *bio_integrity(struct bio *bio)
762{
763 return NULL;
764}
765
766static inline int bioset_integrity_create(struct bio_set *bs, int pool_size)
767{
768 return 0;
769}
770
771static inline void bioset_integrity_free (struct bio_set *bs)
772{
773 return;
774}
775
776static inline bool bio_integrity_prep(struct bio *bio)
777{
778 return true;
779}
780
781static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
782 gfp_t gfp_mask)
783{
784 return 0;
785}
786
787static inline void bio_integrity_advance(struct bio *bio,
788 unsigned int bytes_done)
789{
790 return;
791}
792
793static inline void bio_integrity_trim(struct bio *bio)
794{
795 return;
796}
797
798static inline void bio_integrity_init(void)
799{
800 return;
801}
802
803static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
804{
805 return false;
806}
807
808static inline void *bio_integrity_alloc(struct bio * bio, gfp_t gfp,
809 unsigned int nr)
810{
811 return ERR_PTR(-EINVAL);
812}
813
814static inline int bio_integrity_add_page(struct bio *bio, struct page *page,
815 unsigned int len, unsigned int offset)
816{
817 return 0;
818}
819
820#endif /* CONFIG_BLK_DEV_INTEGRITY */
821
822/*
823 * Mark a bio as polled. Note that for async polled IO, the caller must
824 * expect -EWOULDBLOCK if we cannot allocate a request (or other resources).
825 * We cannot block waiting for requests on polled IO, as those completions
826 * must be found by the caller. This is different than IRQ driven IO, where
827 * it's safe to wait for IO to complete.
828 */
829static inline void bio_set_polled(struct bio *bio, struct kiocb *kiocb)
830{
831 bio->bi_opf |= REQ_HIPRI;
832 if (!is_sync_kiocb(kiocb))
833 bio->bi_opf |= REQ_NOWAIT;
834}
835
836#endif /* CONFIG_BLOCK */
837#endif /* __LINUX_BIO_H */