1/*
2 * Copyright (C) 2001 Jens Axboe <axboe@suse.de>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 *
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public Licens
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-
17 */
18#ifndef __LINUX_BIO_H
19#define __LINUX_BIO_H
20
21#include <linux/highmem.h>
22#include <linux/mempool.h>
23#include <linux/ioprio.h>
24
25#ifdef CONFIG_BLOCK
26/* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */
27#include <linux/blk_types.h>
28
29#define BIO_DEBUG
30
31#ifdef BIO_DEBUG
32#define BIO_BUG_ON BUG_ON
33#else
34#define BIO_BUG_ON
35#endif
36
37#define BIO_MAX_PAGES 256
38
39#define bio_prio(bio) (bio)->bi_ioprio
40#define bio_set_prio(bio, prio) ((bio)->bi_ioprio = prio)
41
42#define bio_iter_iovec(bio, iter) \
43 bvec_iter_bvec((bio)->bi_io_vec, (iter))
44
45#define bio_iter_page(bio, iter) \
46 bvec_iter_page((bio)->bi_io_vec, (iter))
47#define bio_iter_len(bio, iter) \
48 bvec_iter_len((bio)->bi_io_vec, (iter))
49#define bio_iter_offset(bio, iter) \
50 bvec_iter_offset((bio)->bi_io_vec, (iter))
51
52#define bio_page(bio) bio_iter_page((bio), (bio)->bi_iter)
53#define bio_offset(bio) bio_iter_offset((bio), (bio)->bi_iter)
54#define bio_iovec(bio) bio_iter_iovec((bio), (bio)->bi_iter)
55
56#define bio_multiple_segments(bio) \
57 ((bio)->bi_iter.bi_size != bio_iovec(bio).bv_len)
58
59#define bvec_iter_sectors(iter) ((iter).bi_size >> 9)
60#define bvec_iter_end_sector(iter) ((iter).bi_sector + bvec_iter_sectors((iter)))
61
62#define bio_sectors(bio) bvec_iter_sectors((bio)->bi_iter)
63#define bio_end_sector(bio) bvec_iter_end_sector((bio)->bi_iter)
64
65/*
66 * Return the data direction, READ or WRITE.
67 */
68#define bio_data_dir(bio) \
69 (op_is_write(bio_op(bio)) ? WRITE : READ)
70
71/*
72 * Check whether this bio carries any data or not. A NULL bio is allowed.
73 */
74static inline bool bio_has_data(struct bio *bio)
75{
76 if (bio &&
77 bio->bi_iter.bi_size &&
78 bio_op(bio) != REQ_OP_DISCARD &&
79 bio_op(bio) != REQ_OP_SECURE_ERASE &&
80 bio_op(bio) != REQ_OP_WRITE_ZEROES)
81 return true;
82
83 return false;
84}
85
86static inline bool bio_no_advance_iter(struct bio *bio)
87{
88 return bio_op(bio) == REQ_OP_DISCARD ||
89 bio_op(bio) == REQ_OP_SECURE_ERASE ||
90 bio_op(bio) == REQ_OP_WRITE_SAME ||
91 bio_op(bio) == REQ_OP_WRITE_ZEROES;
92}
93
94static inline bool bio_mergeable(struct bio *bio)
95{
96 if (bio->bi_opf & REQ_NOMERGE_FLAGS)
97 return false;
98
99 return true;
100}
101
102static inline unsigned int bio_cur_bytes(struct bio *bio)
103{
104 if (bio_has_data(bio))
105 return bio_iovec(bio).bv_len;
106 else /* dataless requests such as discard */
107 return bio->bi_iter.bi_size;
108}
109
110static inline void *bio_data(struct bio *bio)
111{
112 if (bio_has_data(bio))
113 return page_address(bio_page(bio)) + bio_offset(bio);
114
115 return NULL;
116}
117
118static inline bool bio_full(struct bio *bio)
119{
120 return bio->bi_vcnt >= bio->bi_max_vecs;
121}
122
123#define mp_bvec_for_each_segment(bv, bvl, i, iter_all) \
124 for (bv = bvec_init_iter_all(&iter_all); \
125 (iter_all.done < (bvl)->bv_len) && \
126 (mp_bvec_next_segment((bvl), &iter_all), 1); \
127 iter_all.done += bv->bv_len, i += 1)
128
129/*
130 * drivers should _never_ use the all version - the bio may have been split
131 * before it got to the driver and the driver won't own all of it
132 */
133#define bio_for_each_segment_all(bvl, bio, i, iter_all) \
134 for (i = 0, iter_all.idx = 0; iter_all.idx < (bio)->bi_vcnt; iter_all.idx++) \
135 mp_bvec_for_each_segment(bvl, &((bio)->bi_io_vec[iter_all.idx]), i, iter_all)
136
137static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter,
138 unsigned bytes)
139{
140 iter->bi_sector += bytes >> 9;
141
142 if (bio_no_advance_iter(bio))
143 iter->bi_size -= bytes;
144 else
145 bvec_iter_advance(bio->bi_io_vec, iter, bytes);
146 /* TODO: It is reasonable to complete bio with error here. */
147}
148
149#define __bio_for_each_segment(bvl, bio, iter, start) \
150 for (iter = (start); \
151 (iter).bi_size && \
152 ((bvl = bio_iter_iovec((bio), (iter))), 1); \
153 bio_advance_iter((bio), &(iter), (bvl).bv_len))
154
155#define bio_for_each_segment(bvl, bio, iter) \
156 __bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter)
157
158#define __bio_for_each_bvec(bvl, bio, iter, start) \
159 for (iter = (start); \
160 (iter).bi_size && \
161 ((bvl = mp_bvec_iter_bvec((bio)->bi_io_vec, (iter))), 1); \
162 bio_advance_iter((bio), &(iter), (bvl).bv_len))
163
164/* iterate over multi-page bvec */
165#define bio_for_each_bvec(bvl, bio, iter) \
166 __bio_for_each_bvec(bvl, bio, iter, (bio)->bi_iter)
167
168#define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)
169
170static inline unsigned bio_segments(struct bio *bio)
171{
172 unsigned segs = 0;
173 struct bio_vec bv;
174 struct bvec_iter iter;
175
176 /*
177 * We special case discard/write same/write zeroes, because they
178 * interpret bi_size differently:
179 */
180
181 switch (bio_op(bio)) {
182 case REQ_OP_DISCARD:
183 case REQ_OP_SECURE_ERASE:
184 case REQ_OP_WRITE_ZEROES:
185 return 0;
186 case REQ_OP_WRITE_SAME:
187 return 1;
188 default:
189 break;
190 }
191
192 bio_for_each_segment(bv, bio, iter)
193 segs++;
194
195 return segs;
196}
197
198/*
199 * get a reference to a bio, so it won't disappear. the intended use is
200 * something like:
201 *
202 * bio_get(bio);
203 * submit_bio(rw, bio);
204 * if (bio->bi_flags ...)
205 * do_something
206 * bio_put(bio);
207 *
208 * without the bio_get(), it could potentially complete I/O before submit_bio
209 * returns. and then bio would be freed memory when if (bio->bi_flags ...)
210 * runs
211 */
212static inline void bio_get(struct bio *bio)
213{
214 bio->bi_flags |= (1 << BIO_REFFED);
215 smp_mb__before_atomic();
216 atomic_inc(&bio->__bi_cnt);
217}
218
219static inline void bio_cnt_set(struct bio *bio, unsigned int count)
220{
221 if (count != 1) {
222 bio->bi_flags |= (1 << BIO_REFFED);
223 smp_mb__before_atomic();
224 }
225 atomic_set(&bio->__bi_cnt, count);
226}
227
228static inline bool bio_flagged(struct bio *bio, unsigned int bit)
229{
230 return (bio->bi_flags & (1U << bit)) != 0;
231}
232
233static inline void bio_set_flag(struct bio *bio, unsigned int bit)
234{
235 bio->bi_flags |= (1U << bit);
236}
237
238static inline void bio_clear_flag(struct bio *bio, unsigned int bit)
239{
240 bio->bi_flags &= ~(1U << bit);
241}
242
243static inline void bio_get_first_bvec(struct bio *bio, struct bio_vec *bv)
244{
245 *bv = bio_iovec(bio);
246}
247
248static inline void bio_get_last_bvec(struct bio *bio, struct bio_vec *bv)
249{
250 struct bvec_iter iter = bio->bi_iter;
251 int idx;
252
253 if (unlikely(!bio_multiple_segments(bio))) {
254 *bv = bio_iovec(bio);
255 return;
256 }
257
258 bio_advance_iter(bio, &iter, iter.bi_size);
259
260 if (!iter.bi_bvec_done)
261 idx = iter.bi_idx - 1;
262 else /* in the middle of bvec */
263 idx = iter.bi_idx;
264
265 *bv = bio->bi_io_vec[idx];
266
267 /*
268 * iter.bi_bvec_done records actual length of the last bvec
269 * if this bio ends in the middle of one io vector
270 */
271 if (iter.bi_bvec_done)
272 bv->bv_len = iter.bi_bvec_done;
273}
274
275static inline struct bio_vec *bio_first_bvec_all(struct bio *bio)
276{
277 WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
278 return bio->bi_io_vec;
279}
280
281static inline struct page *bio_first_page_all(struct bio *bio)
282{
283 return bio_first_bvec_all(bio)->bv_page;
284}
285
286static inline struct bio_vec *bio_last_bvec_all(struct bio *bio)
287{
288 WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
289 return &bio->bi_io_vec[bio->bi_vcnt - 1];
290}
291
292enum bip_flags {
293 BIP_BLOCK_INTEGRITY = 1 << 0, /* block layer owns integrity data */
294 BIP_MAPPED_INTEGRITY = 1 << 1, /* ref tag has been remapped */
295 BIP_CTRL_NOCHECK = 1 << 2, /* disable HBA integrity checking */
296 BIP_DISK_NOCHECK = 1 << 3, /* disable disk integrity checking */
297 BIP_IP_CHECKSUM = 1 << 4, /* IP checksum */
298};
299
300/*
301 * bio integrity payload
302 */
303struct bio_integrity_payload {
304 struct bio *bip_bio; /* parent bio */
305
306 struct bvec_iter bip_iter;
307
308 unsigned short bip_slab; /* slab the bip came from */
309 unsigned short bip_vcnt; /* # of integrity bio_vecs */
310 unsigned short bip_max_vcnt; /* integrity bio_vec slots */
311 unsigned short bip_flags; /* control flags */
312
313 struct bvec_iter bio_iter; /* for rewinding parent bio */
314
315 struct work_struct bip_work; /* I/O completion */
316
317 struct bio_vec *bip_vec;
318 struct bio_vec bip_inline_vecs[0];/* embedded bvec array */
319};
320
321#if defined(CONFIG_BLK_DEV_INTEGRITY)
322
323static inline struct bio_integrity_payload *bio_integrity(struct bio *bio)
324{
325 if (bio->bi_opf & REQ_INTEGRITY)
326 return bio->bi_integrity;
327
328 return NULL;
329}
330
331static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
332{
333 struct bio_integrity_payload *bip = bio_integrity(bio);
334
335 if (bip)
336 return bip->bip_flags & flag;
337
338 return false;
339}
340
341static inline sector_t bip_get_seed(struct bio_integrity_payload *bip)
342{
343 return bip->bip_iter.bi_sector;
344}
345
346static inline void bip_set_seed(struct bio_integrity_payload *bip,
347 sector_t seed)
348{
349 bip->bip_iter.bi_sector = seed;
350}
351
352#endif /* CONFIG_BLK_DEV_INTEGRITY */
353
354extern void bio_trim(struct bio *bio, int offset, int size);
355extern struct bio *bio_split(struct bio *bio, int sectors,
356 gfp_t gfp, struct bio_set *bs);
357
358/**
359 * bio_next_split - get next @sectors from a bio, splitting if necessary
360 * @bio: bio to split
361 * @sectors: number of sectors to split from the front of @bio
362 * @gfp: gfp mask
363 * @bs: bio set to allocate from
364 *
365 * Returns a bio representing the next @sectors of @bio - if the bio is smaller
366 * than @sectors, returns the original bio unchanged.
367 */
368static inline struct bio *bio_next_split(struct bio *bio, int sectors,
369 gfp_t gfp, struct bio_set *bs)
370{
371 if (sectors >= bio_sectors(bio))
372 return bio;
373
374 return bio_split(bio, sectors, gfp, bs);
375}
376
377enum {
378 BIOSET_NEED_BVECS = BIT(0),
379 BIOSET_NEED_RESCUER = BIT(1),
380};
381extern int bioset_init(struct bio_set *, unsigned int, unsigned int, int flags);
382extern void bioset_exit(struct bio_set *);
383extern int biovec_init_pool(mempool_t *pool, int pool_entries);
384extern int bioset_init_from_src(struct bio_set *bs, struct bio_set *src);
385
386extern struct bio *bio_alloc_bioset(gfp_t, unsigned int, struct bio_set *);
387extern void bio_put(struct bio *);
388
389extern void __bio_clone_fast(struct bio *, struct bio *);
390extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *);
391
392extern struct bio_set fs_bio_set;
393
394static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
395{
396 return bio_alloc_bioset(gfp_mask, nr_iovecs, &fs_bio_set);
397}
398
399static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
400{
401 return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
402}
403
404extern blk_qc_t submit_bio(struct bio *);
405
406extern void bio_endio(struct bio *);
407
408static inline void bio_io_error(struct bio *bio)
409{
410 bio->bi_status = BLK_STS_IOERR;
411 bio_endio(bio);
412}
413
414static inline void bio_wouldblock_error(struct bio *bio)
415{
416 bio->bi_status = BLK_STS_AGAIN;
417 bio_endio(bio);
418}
419
420struct request_queue;
421extern int bio_phys_segments(struct request_queue *, struct bio *);
422
423extern int submit_bio_wait(struct bio *bio);
424extern void bio_advance(struct bio *, unsigned);
425
426extern void bio_init(struct bio *bio, struct bio_vec *table,
427 unsigned short max_vecs);
428extern void bio_uninit(struct bio *);
429extern void bio_reset(struct bio *);
430void bio_chain(struct bio *, struct bio *);
431
432extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
433extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
434 unsigned int, unsigned int);
435bool __bio_try_merge_page(struct bio *bio, struct page *page,
436 unsigned int len, unsigned int off, bool same_page);
437void __bio_add_page(struct bio *bio, struct page *page,
438 unsigned int len, unsigned int off);
439int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter);
440struct rq_map_data;
441extern struct bio *bio_map_user_iov(struct request_queue *,
442 struct iov_iter *, gfp_t);
443extern void bio_unmap_user(struct bio *);
444extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
445 gfp_t);
446extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
447 gfp_t, int);
448extern void bio_set_pages_dirty(struct bio *bio);
449extern void bio_check_pages_dirty(struct bio *bio);
450
451void generic_start_io_acct(struct request_queue *q, int op,
452 unsigned long sectors, struct hd_struct *part);
453void generic_end_io_acct(struct request_queue *q, int op,
454 struct hd_struct *part,
455 unsigned long start_time);
456
457#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
458# error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
459#endif
460#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
461extern void bio_flush_dcache_pages(struct bio *bi);
462#else
463static inline void bio_flush_dcache_pages(struct bio *bi)
464{
465}
466#endif
467
468extern void bio_copy_data_iter(struct bio *dst, struct bvec_iter *dst_iter,
469 struct bio *src, struct bvec_iter *src_iter);
470extern void bio_copy_data(struct bio *dst, struct bio *src);
471extern void bio_list_copy_data(struct bio *dst, struct bio *src);
472extern void bio_free_pages(struct bio *bio);
473
474extern struct bio *bio_copy_user_iov(struct request_queue *,
475 struct rq_map_data *,
476 struct iov_iter *,
477 gfp_t);
478extern int bio_uncopy_user(struct bio *);
479void zero_fill_bio_iter(struct bio *bio, struct bvec_iter iter);
480
481static inline void zero_fill_bio(struct bio *bio)
482{
483 zero_fill_bio_iter(bio, bio->bi_iter);
484}
485
486extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *);
487extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int);
488extern unsigned int bvec_nr_vecs(unsigned short idx);
489extern const char *bio_devname(struct bio *bio, char *buffer);
490
491#define bio_set_dev(bio, bdev) \
492do { \
493 if ((bio)->bi_disk != (bdev)->bd_disk) \
494 bio_clear_flag(bio, BIO_THROTTLED);\
495 (bio)->bi_disk = (bdev)->bd_disk; \
496 (bio)->bi_partno = (bdev)->bd_partno; \
497 bio_associate_blkg(bio); \
498} while (0)
499
500#define bio_copy_dev(dst, src) \
501do { \
502 (dst)->bi_disk = (src)->bi_disk; \
503 (dst)->bi_partno = (src)->bi_partno; \
504 bio_clone_blkg_association(dst, src); \
505} while (0)
506
507#define bio_dev(bio) \
508 disk_devt((bio)->bi_disk)
509
510#if defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP)
511void bio_associate_blkg_from_page(struct bio *bio, struct page *page);
512#else
513static inline void bio_associate_blkg_from_page(struct bio *bio,
514 struct page *page) { }
515#endif
516
517#ifdef CONFIG_BLK_CGROUP
518void bio_disassociate_blkg(struct bio *bio);
519void bio_associate_blkg(struct bio *bio);
520void bio_associate_blkg_from_css(struct bio *bio,
521 struct cgroup_subsys_state *css);
522void bio_clone_blkg_association(struct bio *dst, struct bio *src);
523#else /* CONFIG_BLK_CGROUP */
524static inline void bio_disassociate_blkg(struct bio *bio) { }
525static inline void bio_associate_blkg(struct bio *bio) { }
526static inline void bio_associate_blkg_from_css(struct bio *bio,
527 struct cgroup_subsys_state *css)
528{ }
529static inline void bio_clone_blkg_association(struct bio *dst,
530 struct bio *src) { }
531#endif /* CONFIG_BLK_CGROUP */
532
533#ifdef CONFIG_HIGHMEM
534/*
535 * remember never ever reenable interrupts between a bvec_kmap_irq and
536 * bvec_kunmap_irq!
537 */
538static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
539{
540 unsigned long addr;
541
542 /*
543 * might not be a highmem page, but the preempt/irq count
544 * balancing is a lot nicer this way
545 */
546 local_irq_save(*flags);
547 addr = (unsigned long) kmap_atomic(bvec->bv_page);
548
549 BUG_ON(addr & ~PAGE_MASK);
550
551 return (char *) addr + bvec->bv_offset;
552}
553
554static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
555{
556 unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
557
558 kunmap_atomic((void *) ptr);
559 local_irq_restore(*flags);
560}
561
562#else
563static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
564{
565 return page_address(bvec->bv_page) + bvec->bv_offset;
566}
567
568static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
569{
570 *flags = 0;
571}
572#endif
573
574/*
575 * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
576 *
577 * A bio_list anchors a singly-linked list of bios chained through the bi_next
578 * member of the bio. The bio_list also caches the last list member to allow
579 * fast access to the tail.
580 */
581struct bio_list {
582 struct bio *head;
583 struct bio *tail;
584};
585
586static inline int bio_list_empty(const struct bio_list *bl)
587{
588 return bl->head == NULL;
589}
590
591static inline void bio_list_init(struct bio_list *bl)
592{
593 bl->head = bl->tail = NULL;
594}
595
596#define BIO_EMPTY_LIST { NULL, NULL }
597
598#define bio_list_for_each(bio, bl) \
599 for (bio = (bl)->head; bio; bio = bio->bi_next)
600
601static inline unsigned bio_list_size(const struct bio_list *bl)
602{
603 unsigned sz = 0;
604 struct bio *bio;
605
606 bio_list_for_each(bio, bl)
607 sz++;
608
609 return sz;
610}
611
612static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
613{
614 bio->bi_next = NULL;
615
616 if (bl->tail)
617 bl->tail->bi_next = bio;
618 else
619 bl->head = bio;
620
621 bl->tail = bio;
622}
623
624static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
625{
626 bio->bi_next = bl->head;
627
628 bl->head = bio;
629
630 if (!bl->tail)
631 bl->tail = bio;
632}
633
634static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
635{
636 if (!bl2->head)
637 return;
638
639 if (bl->tail)
640 bl->tail->bi_next = bl2->head;
641 else
642 bl->head = bl2->head;
643
644 bl->tail = bl2->tail;
645}
646
647static inline void bio_list_merge_head(struct bio_list *bl,
648 struct bio_list *bl2)
649{
650 if (!bl2->head)
651 return;
652
653 if (bl->head)
654 bl2->tail->bi_next = bl->head;
655 else
656 bl->tail = bl2->tail;
657
658 bl->head = bl2->head;
659}
660
661static inline struct bio *bio_list_peek(struct bio_list *bl)
662{
663 return bl->head;
664}
665
666static inline struct bio *bio_list_pop(struct bio_list *bl)
667{
668 struct bio *bio = bl->head;
669
670 if (bio) {
671 bl->head = bl->head->bi_next;
672 if (!bl->head)
673 bl->tail = NULL;
674
675 bio->bi_next = NULL;
676 }
677
678 return bio;
679}
680
681static inline struct bio *bio_list_get(struct bio_list *bl)
682{
683 struct bio *bio = bl->head;
684
685 bl->head = bl->tail = NULL;
686
687 return bio;
688}
689
690/*
691 * Increment chain count for the bio. Make sure the CHAIN flag update
692 * is visible before the raised count.
693 */
694static inline void bio_inc_remaining(struct bio *bio)
695{
696 bio_set_flag(bio, BIO_CHAIN);
697 smp_mb__before_atomic();
698 atomic_inc(&bio->__bi_remaining);
699}
700
701/*
702 * bio_set is used to allow other portions of the IO system to
703 * allocate their own private memory pools for bio and iovec structures.
704 * These memory pools in turn all allocate from the bio_slab
705 * and the bvec_slabs[].
706 */
707#define BIO_POOL_SIZE 2
708
709struct bio_set {
710 struct kmem_cache *bio_slab;
711 unsigned int front_pad;
712
713 mempool_t bio_pool;
714 mempool_t bvec_pool;
715#if defined(CONFIG_BLK_DEV_INTEGRITY)
716 mempool_t bio_integrity_pool;
717 mempool_t bvec_integrity_pool;
718#endif
719
720 /*
721 * Deadlock avoidance for stacking block drivers: see comments in
722 * bio_alloc_bioset() for details
723 */
724 spinlock_t rescue_lock;
725 struct bio_list rescue_list;
726 struct work_struct rescue_work;
727 struct workqueue_struct *rescue_workqueue;
728};
729
730struct biovec_slab {
731 int nr_vecs;
732 char *name;
733 struct kmem_cache *slab;
734};
735
736static inline bool bioset_initialized(struct bio_set *bs)
737{
738 return bs->bio_slab != NULL;
739}
740
741/*
742 * a small number of entries is fine, not going to be performance critical.
743 * basically we just need to survive
744 */
745#define BIO_SPLIT_ENTRIES 2
746
747#if defined(CONFIG_BLK_DEV_INTEGRITY)
748
749#define bip_for_each_vec(bvl, bip, iter) \
750 for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
751
752#define bio_for_each_integrity_vec(_bvl, _bio, _iter) \
753 for_each_bio(_bio) \
754 bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
755
756extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
757extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
758extern bool bio_integrity_prep(struct bio *);
759extern void bio_integrity_advance(struct bio *, unsigned int);
760extern void bio_integrity_trim(struct bio *);
761extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t);
762extern int bioset_integrity_create(struct bio_set *, int);
763extern void bioset_integrity_free(struct bio_set *);
764extern void bio_integrity_init(void);
765
766#else /* CONFIG_BLK_DEV_INTEGRITY */
767
768static inline void *bio_integrity(struct bio *bio)
769{
770 return NULL;
771}
772
773static inline int bioset_integrity_create(struct bio_set *bs, int pool_size)
774{
775 return 0;
776}
777
778static inline void bioset_integrity_free (struct bio_set *bs)
779{
780 return;
781}
782
783static inline bool bio_integrity_prep(struct bio *bio)
784{
785 return true;
786}
787
788static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
789 gfp_t gfp_mask)
790{
791 return 0;
792}
793
794static inline void bio_integrity_advance(struct bio *bio,
795 unsigned int bytes_done)
796{
797 return;
798}
799
800static inline void bio_integrity_trim(struct bio *bio)
801{
802 return;
803}
804
805static inline void bio_integrity_init(void)
806{
807 return;
808}
809
810static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
811{
812 return false;
813}
814
815static inline void *bio_integrity_alloc(struct bio * bio, gfp_t gfp,
816 unsigned int nr)
817{
818 return ERR_PTR(-EINVAL);
819}
820
821static inline int bio_integrity_add_page(struct bio *bio, struct page *page,
822 unsigned int len, unsigned int offset)
823{
824 return 0;
825}
826
827#endif /* CONFIG_BLK_DEV_INTEGRITY */
828
829/*
830 * Mark a bio as polled. Note that for async polled IO, the caller must
831 * expect -EWOULDBLOCK if we cannot allocate a request (or other resources).
832 * We cannot block waiting for requests on polled IO, as those completions
833 * must be found by the caller. This is different than IRQ driven IO, where
834 * it's safe to wait for IO to complete.
835 */
836static inline void bio_set_polled(struct bio *bio, struct kiocb *kiocb)
837{
838 bio->bi_opf |= REQ_HIPRI;
839 if (!is_sync_kiocb(kiocb))
840 bio->bi_opf |= REQ_NOWAIT;
841}
842
843#endif /* CONFIG_BLOCK */
844#endif /* __LINUX_BIO_H */
845