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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/*
2 * 2.5 block I/O model
3 *
4 * Copyright (C) 2001 Jens Axboe <axboe@suse.de>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 *
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public Licens
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-
19 */
20#ifndef __LINUX_BIO_H
21#define __LINUX_BIO_H
22
23#include <linux/highmem.h>
24#include <linux/mempool.h>
25#include <linux/ioprio.h>
26#include <linux/bug.h>
27
28#ifdef CONFIG_BLOCK
29
30#include <asm/io.h>
31
32/* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */
33#include <linux/blk_types.h>
34
35#define BIO_DEBUG
36
37#ifdef BIO_DEBUG
38#define BIO_BUG_ON BUG_ON
39#else
40#define BIO_BUG_ON
41#endif
42
43#define BIO_MAX_PAGES 256
44#define BIO_MAX_SIZE (BIO_MAX_PAGES << PAGE_CACHE_SHIFT)
45#define BIO_MAX_SECTORS (BIO_MAX_SIZE >> 9)
46
47/*
48 * upper 16 bits of bi_rw define the io priority of this bio
49 */
50#define BIO_PRIO_SHIFT (8 * sizeof(unsigned long) - IOPRIO_BITS)
51#define bio_prio(bio) ((bio)->bi_rw >> BIO_PRIO_SHIFT)
52#define bio_prio_valid(bio) ioprio_valid(bio_prio(bio))
53
54#define bio_set_prio(bio, prio) do { \
55 WARN_ON(prio >= (1 << IOPRIO_BITS)); \
56 (bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1); \
57 (bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT); \
58} while (0)
59
60/*
61 * various member access, note that bio_data should of course not be used
62 * on highmem page vectors
63 */
64#define bio_iovec_idx(bio, idx) (&((bio)->bi_io_vec[(idx)]))
65#define bio_iovec(bio) bio_iovec_idx((bio), (bio)->bi_idx)
66#define bio_page(bio) bio_iovec((bio))->bv_page
67#define bio_offset(bio) bio_iovec((bio))->bv_offset
68#define bio_segments(bio) ((bio)->bi_vcnt - (bio)->bi_idx)
69#define bio_sectors(bio) ((bio)->bi_size >> 9)
70
71static inline unsigned int bio_cur_bytes(struct bio *bio)
72{
73 if (bio->bi_vcnt)
74 return bio_iovec(bio)->bv_len;
75 else /* dataless requests such as discard */
76 return bio->bi_size;
77}
78
79static inline void *bio_data(struct bio *bio)
80{
81 if (bio->bi_vcnt)
82 return page_address(bio_page(bio)) + bio_offset(bio);
83
84 return NULL;
85}
86
87static inline int bio_has_allocated_vec(struct bio *bio)
88{
89 return bio->bi_io_vec && bio->bi_io_vec != bio->bi_inline_vecs;
90}
91
92/*
93 * will die
94 */
95#define bio_to_phys(bio) (page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
96#define bvec_to_phys(bv) (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
97
98/*
99 * queues that have highmem support enabled may still need to revert to
100 * PIO transfers occasionally and thus map high pages temporarily. For
101 * permanent PIO fall back, user is probably better off disabling highmem
102 * I/O completely on that queue (see ide-dma for example)
103 */
104#define __bio_kmap_atomic(bio, idx, kmtype) \
105 (kmap_atomic(bio_iovec_idx((bio), (idx))->bv_page) + \
106 bio_iovec_idx((bio), (idx))->bv_offset)
107
108#define __bio_kunmap_atomic(addr, kmtype) kunmap_atomic(addr)
109
110/*
111 * merge helpers etc
112 */
113
114#define __BVEC_END(bio) bio_iovec_idx((bio), (bio)->bi_vcnt - 1)
115#define __BVEC_START(bio) bio_iovec_idx((bio), (bio)->bi_idx)
116
117/* Default implementation of BIOVEC_PHYS_MERGEABLE */
118#define __BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
119 ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
120
121/*
122 * allow arch override, for eg virtualized architectures (put in asm/io.h)
123 */
124#ifndef BIOVEC_PHYS_MERGEABLE
125#define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
126 __BIOVEC_PHYS_MERGEABLE(vec1, vec2)
127#endif
128
129#define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
130 (((addr1) | (mask)) == (((addr2) - 1) | (mask)))
131#define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
132 __BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q)))
133#define BIO_SEG_BOUNDARY(q, b1, b2) \
134 BIOVEC_SEG_BOUNDARY((q), __BVEC_END((b1)), __BVEC_START((b2)))
135
136#define bio_io_error(bio) bio_endio((bio), -EIO)
137
138/*
139 * drivers should not use the __ version unless they _really_ want to
140 * run through the entire bio and not just pending pieces
141 */
142#define __bio_for_each_segment(bvl, bio, i, start_idx) \
143 for (bvl = bio_iovec_idx((bio), (start_idx)), i = (start_idx); \
144 i < (bio)->bi_vcnt; \
145 bvl++, i++)
146
147#define bio_for_each_segment(bvl, bio, i) \
148 __bio_for_each_segment(bvl, bio, i, (bio)->bi_idx)
149
150/*
151 * get a reference to a bio, so it won't disappear. the intended use is
152 * something like:
153 *
154 * bio_get(bio);
155 * submit_bio(rw, bio);
156 * if (bio->bi_flags ...)
157 * do_something
158 * bio_put(bio);
159 *
160 * without the bio_get(), it could potentially complete I/O before submit_bio
161 * returns. and then bio would be freed memory when if (bio->bi_flags ...)
162 * runs
163 */
164#define bio_get(bio) atomic_inc(&(bio)->bi_cnt)
165
166#if defined(CONFIG_BLK_DEV_INTEGRITY)
167/*
168 * bio integrity payload
169 */
170struct bio_integrity_payload {
171 struct bio *bip_bio; /* parent bio */
172
173 sector_t bip_sector; /* virtual start sector */
174
175 void *bip_buf; /* generated integrity data */
176 bio_end_io_t *bip_end_io; /* saved I/O completion fn */
177
178 unsigned int bip_size;
179
180 unsigned short bip_slab; /* slab the bip came from */
181 unsigned short bip_vcnt; /* # of integrity bio_vecs */
182 unsigned short bip_idx; /* current bip_vec index */
183
184 struct work_struct bip_work; /* I/O completion */
185 struct bio_vec bip_vec[0]; /* embedded bvec array */
186};
187#endif /* CONFIG_BLK_DEV_INTEGRITY */
188
189/*
190 * A bio_pair is used when we need to split a bio.
191 * This can only happen for a bio that refers to just one
192 * page of data, and in the unusual situation when the
193 * page crosses a chunk/device boundary
194 *
195 * The address of the master bio is stored in bio1.bi_private
196 * The address of the pool the pair was allocated from is stored
197 * in bio2.bi_private
198 */
199struct bio_pair {
200 struct bio bio1, bio2;
201 struct bio_vec bv1, bv2;
202#if defined(CONFIG_BLK_DEV_INTEGRITY)
203 struct bio_integrity_payload bip1, bip2;
204 struct bio_vec iv1, iv2;
205#endif
206 atomic_t cnt;
207 int error;
208};
209extern struct bio_pair *bio_split(struct bio *bi, int first_sectors);
210extern void bio_pair_release(struct bio_pair *dbio);
211
212extern struct bio_set *bioset_create(unsigned int, unsigned int);
213extern void bioset_free(struct bio_set *);
214
215extern struct bio *bio_alloc(gfp_t, unsigned int);
216extern struct bio *bio_kmalloc(gfp_t, unsigned int);
217extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
218extern void bio_put(struct bio *);
219extern void bio_free(struct bio *, struct bio_set *);
220
221extern void bio_endio(struct bio *, int);
222struct request_queue;
223extern int bio_phys_segments(struct request_queue *, struct bio *);
224
225extern void __bio_clone(struct bio *, struct bio *);
226extern struct bio *bio_clone(struct bio *, gfp_t);
227
228extern void bio_init(struct bio *);
229
230extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
231extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
232 unsigned int, unsigned int);
233extern int bio_get_nr_vecs(struct block_device *);
234extern sector_t bio_sector_offset(struct bio *, unsigned short, unsigned int);
235extern struct bio *bio_map_user(struct request_queue *, struct block_device *,
236 unsigned long, unsigned int, int, gfp_t);
237struct sg_iovec;
238struct rq_map_data;
239extern struct bio *bio_map_user_iov(struct request_queue *,
240 struct block_device *,
241 struct sg_iovec *, int, int, gfp_t);
242extern void bio_unmap_user(struct bio *);
243extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
244 gfp_t);
245extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
246 gfp_t, int);
247extern void bio_set_pages_dirty(struct bio *bio);
248extern void bio_check_pages_dirty(struct bio *bio);
249
250#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
251# error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
252#endif
253#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
254extern void bio_flush_dcache_pages(struct bio *bi);
255#else
256static inline void bio_flush_dcache_pages(struct bio *bi)
257{
258}
259#endif
260
261extern struct bio *bio_copy_user(struct request_queue *, struct rq_map_data *,
262 unsigned long, unsigned int, int, gfp_t);
263extern struct bio *bio_copy_user_iov(struct request_queue *,
264 struct rq_map_data *, struct sg_iovec *,
265 int, int, gfp_t);
266extern int bio_uncopy_user(struct bio *);
267void zero_fill_bio(struct bio *bio);
268extern struct bio_vec *bvec_alloc_bs(gfp_t, int, unsigned long *, struct bio_set *);
269extern void bvec_free_bs(struct bio_set *, struct bio_vec *, unsigned int);
270extern unsigned int bvec_nr_vecs(unsigned short idx);
271
272#ifdef CONFIG_BLK_CGROUP
273int bio_associate_current(struct bio *bio);
274void bio_disassociate_task(struct bio *bio);
275#else /* CONFIG_BLK_CGROUP */
276static inline int bio_associate_current(struct bio *bio) { return -ENOENT; }
277static inline void bio_disassociate_task(struct bio *bio) { }
278#endif /* CONFIG_BLK_CGROUP */
279
280/*
281 * bio_set is used to allow other portions of the IO system to
282 * allocate their own private memory pools for bio and iovec structures.
283 * These memory pools in turn all allocate from the bio_slab
284 * and the bvec_slabs[].
285 */
286#define BIO_POOL_SIZE 2
287#define BIOVEC_NR_POOLS 6
288#define BIOVEC_MAX_IDX (BIOVEC_NR_POOLS - 1)
289
290struct bio_set {
291 struct kmem_cache *bio_slab;
292 unsigned int front_pad;
293
294 mempool_t *bio_pool;
295#if defined(CONFIG_BLK_DEV_INTEGRITY)
296 mempool_t *bio_integrity_pool;
297#endif
298 mempool_t *bvec_pool;
299};
300
301struct biovec_slab {
302 int nr_vecs;
303 char *name;
304 struct kmem_cache *slab;
305};
306
307extern struct bio_set *fs_bio_set;
308
309/*
310 * a small number of entries is fine, not going to be performance critical.
311 * basically we just need to survive
312 */
313#define BIO_SPLIT_ENTRIES 2
314
315#ifdef CONFIG_HIGHMEM
316/*
317 * remember never ever reenable interrupts between a bvec_kmap_irq and
318 * bvec_kunmap_irq!
319 */
320static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
321{
322 unsigned long addr;
323
324 /*
325 * might not be a highmem page, but the preempt/irq count
326 * balancing is a lot nicer this way
327 */
328 local_irq_save(*flags);
329 addr = (unsigned long) kmap_atomic(bvec->bv_page);
330
331 BUG_ON(addr & ~PAGE_MASK);
332
333 return (char *) addr + bvec->bv_offset;
334}
335
336static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
337{
338 unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
339
340 kunmap_atomic((void *) ptr);
341 local_irq_restore(*flags);
342}
343
344#else
345static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
346{
347 return page_address(bvec->bv_page) + bvec->bv_offset;
348}
349
350static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
351{
352 *flags = 0;
353}
354#endif
355
356static inline char *__bio_kmap_irq(struct bio *bio, unsigned short idx,
357 unsigned long *flags)
358{
359 return bvec_kmap_irq(bio_iovec_idx(bio, idx), flags);
360}
361#define __bio_kunmap_irq(buf, flags) bvec_kunmap_irq(buf, flags)
362
363#define bio_kmap_irq(bio, flags) \
364 __bio_kmap_irq((bio), (bio)->bi_idx, (flags))
365#define bio_kunmap_irq(buf,flags) __bio_kunmap_irq(buf, flags)
366
367/*
368 * Check whether this bio carries any data or not. A NULL bio is allowed.
369 */
370static inline int bio_has_data(struct bio *bio)
371{
372 return bio && bio->bi_io_vec != NULL;
373}
374
375/*
376 * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
377 *
378 * A bio_list anchors a singly-linked list of bios chained through the bi_next
379 * member of the bio. The bio_list also caches the last list member to allow
380 * fast access to the tail.
381 */
382struct bio_list {
383 struct bio *head;
384 struct bio *tail;
385};
386
387static inline int bio_list_empty(const struct bio_list *bl)
388{
389 return bl->head == NULL;
390}
391
392static inline void bio_list_init(struct bio_list *bl)
393{
394 bl->head = bl->tail = NULL;
395}
396
397#define bio_list_for_each(bio, bl) \
398 for (bio = (bl)->head; bio; bio = bio->bi_next)
399
400static inline unsigned bio_list_size(const struct bio_list *bl)
401{
402 unsigned sz = 0;
403 struct bio *bio;
404
405 bio_list_for_each(bio, bl)
406 sz++;
407
408 return sz;
409}
410
411static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
412{
413 bio->bi_next = NULL;
414
415 if (bl->tail)
416 bl->tail->bi_next = bio;
417 else
418 bl->head = bio;
419
420 bl->tail = bio;
421}
422
423static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
424{
425 bio->bi_next = bl->head;
426
427 bl->head = bio;
428
429 if (!bl->tail)
430 bl->tail = bio;
431}
432
433static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
434{
435 if (!bl2->head)
436 return;
437
438 if (bl->tail)
439 bl->tail->bi_next = bl2->head;
440 else
441 bl->head = bl2->head;
442
443 bl->tail = bl2->tail;
444}
445
446static inline void bio_list_merge_head(struct bio_list *bl,
447 struct bio_list *bl2)
448{
449 if (!bl2->head)
450 return;
451
452 if (bl->head)
453 bl2->tail->bi_next = bl->head;
454 else
455 bl->tail = bl2->tail;
456
457 bl->head = bl2->head;
458}
459
460static inline struct bio *bio_list_peek(struct bio_list *bl)
461{
462 return bl->head;
463}
464
465static inline struct bio *bio_list_pop(struct bio_list *bl)
466{
467 struct bio *bio = bl->head;
468
469 if (bio) {
470 bl->head = bl->head->bi_next;
471 if (!bl->head)
472 bl->tail = NULL;
473
474 bio->bi_next = NULL;
475 }
476
477 return bio;
478}
479
480static inline struct bio *bio_list_get(struct bio_list *bl)
481{
482 struct bio *bio = bl->head;
483
484 bl->head = bl->tail = NULL;
485
486 return bio;
487}
488
489#if defined(CONFIG_BLK_DEV_INTEGRITY)
490
491#define bip_vec_idx(bip, idx) (&(bip->bip_vec[(idx)]))
492#define bip_vec(bip) bip_vec_idx(bip, 0)
493
494#define __bip_for_each_vec(bvl, bip, i, start_idx) \
495 for (bvl = bip_vec_idx((bip), (start_idx)), i = (start_idx); \
496 i < (bip)->bip_vcnt; \
497 bvl++, i++)
498
499#define bip_for_each_vec(bvl, bip, i) \
500 __bip_for_each_vec(bvl, bip, i, (bip)->bip_idx)
501
502#define bio_for_each_integrity_vec(_bvl, _bio, _iter) \
503 for_each_bio(_bio) \
504 bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
505
506#define bio_integrity(bio) (bio->bi_integrity != NULL)
507
508extern struct bio_integrity_payload *bio_integrity_alloc_bioset(struct bio *, gfp_t, unsigned int, struct bio_set *);
509extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
510extern void bio_integrity_free(struct bio *, struct bio_set *);
511extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
512extern int bio_integrity_enabled(struct bio *bio);
513extern int bio_integrity_set_tag(struct bio *, void *, unsigned int);
514extern int bio_integrity_get_tag(struct bio *, void *, unsigned int);
515extern int bio_integrity_prep(struct bio *);
516extern void bio_integrity_endio(struct bio *, int);
517extern void bio_integrity_advance(struct bio *, unsigned int);
518extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
519extern void bio_integrity_split(struct bio *, struct bio_pair *, int);
520extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t, struct bio_set *);
521extern int bioset_integrity_create(struct bio_set *, int);
522extern void bioset_integrity_free(struct bio_set *);
523extern void bio_integrity_init(void);
524
525#else /* CONFIG_BLK_DEV_INTEGRITY */
526
527static inline int bio_integrity(struct bio *bio)
528{
529 return 0;
530}
531
532static inline int bio_integrity_enabled(struct bio *bio)
533{
534 return 0;
535}
536
537static inline int bioset_integrity_create(struct bio_set *bs, int pool_size)
538{
539 return 0;
540}
541
542static inline void bioset_integrity_free (struct bio_set *bs)
543{
544 return;
545}
546
547static inline int bio_integrity_prep(struct bio *bio)
548{
549 return 0;
550}
551
552static inline void bio_integrity_free(struct bio *bio, struct bio_set *bs)
553{
554 return;
555}
556
557static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
558 gfp_t gfp_mask, struct bio_set *bs)
559{
560 return 0;
561}
562
563static inline void bio_integrity_split(struct bio *bio, struct bio_pair *bp,
564 int sectors)
565{
566 return;
567}
568
569static inline void bio_integrity_advance(struct bio *bio,
570 unsigned int bytes_done)
571{
572 return;
573}
574
575static inline void bio_integrity_trim(struct bio *bio, unsigned int offset,
576 unsigned int sectors)
577{
578 return;
579}
580
581static inline void bio_integrity_init(void)
582{
583 return;
584}
585
586#endif /* CONFIG_BLK_DEV_INTEGRITY */
587
588#endif /* CONFIG_BLOCK */
589#endif /* __LINUX_BIO_H */