Linux kernel mirror (for testing)
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linux
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#include <linux/bug.h>
25
26#ifdef CONFIG_BLOCK
27
28#include <asm/io.h>
29
30/* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */
31#include <linux/blk_types.h>
32
33#define BIO_DEBUG
34
35#ifdef BIO_DEBUG
36#define BIO_BUG_ON BUG_ON
37#else
38#define BIO_BUG_ON
39#endif
40
41#ifdef CONFIG_THP_SWAP
42#if HPAGE_PMD_NR > 256
43#define BIO_MAX_PAGES HPAGE_PMD_NR
44#else
45#define BIO_MAX_PAGES 256
46#endif
47#else
48#define BIO_MAX_PAGES 256
49#endif
50
51#define bio_prio(bio) (bio)->bi_ioprio
52#define bio_set_prio(bio, prio) ((bio)->bi_ioprio = prio)
53
54#define bio_iter_iovec(bio, iter) \
55 bvec_iter_bvec((bio)->bi_io_vec, (iter))
56
57#define bio_iter_page(bio, iter) \
58 bvec_iter_page((bio)->bi_io_vec, (iter))
59#define bio_iter_len(bio, iter) \
60 bvec_iter_len((bio)->bi_io_vec, (iter))
61#define bio_iter_offset(bio, iter) \
62 bvec_iter_offset((bio)->bi_io_vec, (iter))
63
64#define bio_page(bio) bio_iter_page((bio), (bio)->bi_iter)
65#define bio_offset(bio) bio_iter_offset((bio), (bio)->bi_iter)
66#define bio_iovec(bio) bio_iter_iovec((bio), (bio)->bi_iter)
67
68#define bio_multiple_segments(bio) \
69 ((bio)->bi_iter.bi_size != bio_iovec(bio).bv_len)
70#define bio_sectors(bio) ((bio)->bi_iter.bi_size >> 9)
71#define bio_end_sector(bio) ((bio)->bi_iter.bi_sector + bio_sectors((bio)))
72
73/*
74 * Return the data direction, READ or WRITE.
75 */
76#define bio_data_dir(bio) \
77 (op_is_write(bio_op(bio)) ? WRITE : READ)
78
79/*
80 * Check whether this bio carries any data or not. A NULL bio is allowed.
81 */
82static inline bool bio_has_data(struct bio *bio)
83{
84 if (bio &&
85 bio->bi_iter.bi_size &&
86 bio_op(bio) != REQ_OP_DISCARD &&
87 bio_op(bio) != REQ_OP_SECURE_ERASE &&
88 bio_op(bio) != REQ_OP_WRITE_ZEROES)
89 return true;
90
91 return false;
92}
93
94static inline bool bio_no_advance_iter(struct bio *bio)
95{
96 return bio_op(bio) == REQ_OP_DISCARD ||
97 bio_op(bio) == REQ_OP_SECURE_ERASE ||
98 bio_op(bio) == REQ_OP_WRITE_SAME ||
99 bio_op(bio) == REQ_OP_WRITE_ZEROES;
100}
101
102static inline bool bio_mergeable(struct bio *bio)
103{
104 if (bio->bi_opf & REQ_NOMERGE_FLAGS)
105 return false;
106
107 return true;
108}
109
110static inline unsigned int bio_cur_bytes(struct bio *bio)
111{
112 if (bio_has_data(bio))
113 return bio_iovec(bio).bv_len;
114 else /* dataless requests such as discard */
115 return bio->bi_iter.bi_size;
116}
117
118static inline void *bio_data(struct bio *bio)
119{
120 if (bio_has_data(bio))
121 return page_address(bio_page(bio)) + bio_offset(bio);
122
123 return NULL;
124}
125
126/*
127 * will die
128 */
129#define bvec_to_phys(bv) (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
130
131/*
132 * merge helpers etc
133 */
134
135/* Default implementation of BIOVEC_PHYS_MERGEABLE */
136#define __BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
137 ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
138
139/*
140 * allow arch override, for eg virtualized architectures (put in asm/io.h)
141 */
142#ifndef BIOVEC_PHYS_MERGEABLE
143#define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
144 __BIOVEC_PHYS_MERGEABLE(vec1, vec2)
145#endif
146
147#define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
148 (((addr1) | (mask)) == (((addr2) - 1) | (mask)))
149#define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
150 __BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q)))
151
152/*
153 * drivers should _never_ use the all version - the bio may have been split
154 * before it got to the driver and the driver won't own all of it
155 */
156#define bio_for_each_segment_all(bvl, bio, i) \
157 for (i = 0, bvl = (bio)->bi_io_vec; i < (bio)->bi_vcnt; i++, bvl++)
158
159static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter,
160 unsigned bytes)
161{
162 iter->bi_sector += bytes >> 9;
163
164 if (bio_no_advance_iter(bio)) {
165 iter->bi_size -= bytes;
166 iter->bi_done += bytes;
167 } else {
168 bvec_iter_advance(bio->bi_io_vec, iter, bytes);
169 /* TODO: It is reasonable to complete bio with error here. */
170 }
171}
172
173static inline bool bio_rewind_iter(struct bio *bio, struct bvec_iter *iter,
174 unsigned int bytes)
175{
176 iter->bi_sector -= bytes >> 9;
177
178 if (bio_no_advance_iter(bio)) {
179 iter->bi_size += bytes;
180 iter->bi_done -= bytes;
181 return true;
182 }
183
184 return bvec_iter_rewind(bio->bi_io_vec, iter, bytes);
185}
186
187#define __bio_for_each_segment(bvl, bio, iter, start) \
188 for (iter = (start); \
189 (iter).bi_size && \
190 ((bvl = bio_iter_iovec((bio), (iter))), 1); \
191 bio_advance_iter((bio), &(iter), (bvl).bv_len))
192
193#define bio_for_each_segment(bvl, bio, iter) \
194 __bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter)
195
196#define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)
197
198static inline unsigned bio_segments(struct bio *bio)
199{
200 unsigned segs = 0;
201 struct bio_vec bv;
202 struct bvec_iter iter;
203
204 /*
205 * We special case discard/write same/write zeroes, because they
206 * interpret bi_size differently:
207 */
208
209 switch (bio_op(bio)) {
210 case REQ_OP_DISCARD:
211 case REQ_OP_SECURE_ERASE:
212 case REQ_OP_WRITE_ZEROES:
213 return 0;
214 case REQ_OP_WRITE_SAME:
215 return 1;
216 default:
217 break;
218 }
219
220 bio_for_each_segment(bv, bio, iter)
221 segs++;
222
223 return segs;
224}
225
226/*
227 * get a reference to a bio, so it won't disappear. the intended use is
228 * something like:
229 *
230 * bio_get(bio);
231 * submit_bio(rw, bio);
232 * if (bio->bi_flags ...)
233 * do_something
234 * bio_put(bio);
235 *
236 * without the bio_get(), it could potentially complete I/O before submit_bio
237 * returns. and then bio would be freed memory when if (bio->bi_flags ...)
238 * runs
239 */
240static inline void bio_get(struct bio *bio)
241{
242 bio->bi_flags |= (1 << BIO_REFFED);
243 smp_mb__before_atomic();
244 atomic_inc(&bio->__bi_cnt);
245}
246
247static inline void bio_cnt_set(struct bio *bio, unsigned int count)
248{
249 if (count != 1) {
250 bio->bi_flags |= (1 << BIO_REFFED);
251 smp_mb__before_atomic();
252 }
253 atomic_set(&bio->__bi_cnt, count);
254}
255
256static inline bool bio_flagged(struct bio *bio, unsigned int bit)
257{
258 return (bio->bi_flags & (1U << bit)) != 0;
259}
260
261static inline void bio_set_flag(struct bio *bio, unsigned int bit)
262{
263 bio->bi_flags |= (1U << bit);
264}
265
266static inline void bio_clear_flag(struct bio *bio, unsigned int bit)
267{
268 bio->bi_flags &= ~(1U << bit);
269}
270
271static inline void bio_get_first_bvec(struct bio *bio, struct bio_vec *bv)
272{
273 *bv = bio_iovec(bio);
274}
275
276static inline void bio_get_last_bvec(struct bio *bio, struct bio_vec *bv)
277{
278 struct bvec_iter iter = bio->bi_iter;
279 int idx;
280
281 if (unlikely(!bio_multiple_segments(bio))) {
282 *bv = bio_iovec(bio);
283 return;
284 }
285
286 bio_advance_iter(bio, &iter, iter.bi_size);
287
288 if (!iter.bi_bvec_done)
289 idx = iter.bi_idx - 1;
290 else /* in the middle of bvec */
291 idx = iter.bi_idx;
292
293 *bv = bio->bi_io_vec[idx];
294
295 /*
296 * iter.bi_bvec_done records actual length of the last bvec
297 * if this bio ends in the middle of one io vector
298 */
299 if (iter.bi_bvec_done)
300 bv->bv_len = iter.bi_bvec_done;
301}
302
303static inline unsigned bio_pages_all(struct bio *bio)
304{
305 WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
306 return bio->bi_vcnt;
307}
308
309static inline struct bio_vec *bio_first_bvec_all(struct bio *bio)
310{
311 WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
312 return bio->bi_io_vec;
313}
314
315static inline struct page *bio_first_page_all(struct bio *bio)
316{
317 return bio_first_bvec_all(bio)->bv_page;
318}
319
320static inline struct bio_vec *bio_last_bvec_all(struct bio *bio)
321{
322 WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
323 return &bio->bi_io_vec[bio->bi_vcnt - 1];
324}
325
326enum bip_flags {
327 BIP_BLOCK_INTEGRITY = 1 << 0, /* block layer owns integrity data */
328 BIP_MAPPED_INTEGRITY = 1 << 1, /* ref tag has been remapped */
329 BIP_CTRL_NOCHECK = 1 << 2, /* disable HBA integrity checking */
330 BIP_DISK_NOCHECK = 1 << 3, /* disable disk integrity checking */
331 BIP_IP_CHECKSUM = 1 << 4, /* IP checksum */
332};
333
334/*
335 * bio integrity payload
336 */
337struct bio_integrity_payload {
338 struct bio *bip_bio; /* parent bio */
339
340 struct bvec_iter bip_iter;
341
342 unsigned short bip_slab; /* slab the bip came from */
343 unsigned short bip_vcnt; /* # of integrity bio_vecs */
344 unsigned short bip_max_vcnt; /* integrity bio_vec slots */
345 unsigned short bip_flags; /* control flags */
346
347 struct work_struct bip_work; /* I/O completion */
348
349 struct bio_vec *bip_vec;
350 struct bio_vec bip_inline_vecs[0];/* embedded bvec array */
351};
352
353#if defined(CONFIG_BLK_DEV_INTEGRITY)
354
355static inline struct bio_integrity_payload *bio_integrity(struct bio *bio)
356{
357 if (bio->bi_opf & REQ_INTEGRITY)
358 return bio->bi_integrity;
359
360 return NULL;
361}
362
363static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
364{
365 struct bio_integrity_payload *bip = bio_integrity(bio);
366
367 if (bip)
368 return bip->bip_flags & flag;
369
370 return false;
371}
372
373static inline sector_t bip_get_seed(struct bio_integrity_payload *bip)
374{
375 return bip->bip_iter.bi_sector;
376}
377
378static inline void bip_set_seed(struct bio_integrity_payload *bip,
379 sector_t seed)
380{
381 bip->bip_iter.bi_sector = seed;
382}
383
384#endif /* CONFIG_BLK_DEV_INTEGRITY */
385
386extern void bio_trim(struct bio *bio, int offset, int size);
387extern struct bio *bio_split(struct bio *bio, int sectors,
388 gfp_t gfp, struct bio_set *bs);
389
390/**
391 * bio_next_split - get next @sectors from a bio, splitting if necessary
392 * @bio: bio to split
393 * @sectors: number of sectors to split from the front of @bio
394 * @gfp: gfp mask
395 * @bs: bio set to allocate from
396 *
397 * Returns a bio representing the next @sectors of @bio - if the bio is smaller
398 * than @sectors, returns the original bio unchanged.
399 */
400static inline struct bio *bio_next_split(struct bio *bio, int sectors,
401 gfp_t gfp, struct bio_set *bs)
402{
403 if (sectors >= bio_sectors(bio))
404 return bio;
405
406 return bio_split(bio, sectors, gfp, bs);
407}
408
409extern struct bio_set *bioset_create(unsigned int, unsigned int, int flags);
410enum {
411 BIOSET_NEED_BVECS = BIT(0),
412 BIOSET_NEED_RESCUER = BIT(1),
413};
414extern void bioset_free(struct bio_set *);
415extern mempool_t *biovec_create_pool(int pool_entries);
416
417extern struct bio *bio_alloc_bioset(gfp_t, unsigned int, struct bio_set *);
418extern void bio_put(struct bio *);
419
420extern void __bio_clone_fast(struct bio *, struct bio *);
421extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *);
422extern struct bio *bio_clone_bioset(struct bio *, gfp_t, struct bio_set *bs);
423
424extern struct bio_set *fs_bio_set;
425
426static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
427{
428 return bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set);
429}
430
431static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
432{
433 return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
434}
435
436static inline struct bio *bio_clone_kmalloc(struct bio *bio, gfp_t gfp_mask)
437{
438 return bio_clone_bioset(bio, gfp_mask, NULL);
439
440}
441
442extern blk_qc_t submit_bio(struct bio *);
443
444extern void bio_endio(struct bio *);
445
446static inline void bio_io_error(struct bio *bio)
447{
448 bio->bi_status = BLK_STS_IOERR;
449 bio_endio(bio);
450}
451
452static inline void bio_wouldblock_error(struct bio *bio)
453{
454 bio->bi_status = BLK_STS_AGAIN;
455 bio_endio(bio);
456}
457
458struct request_queue;
459extern int bio_phys_segments(struct request_queue *, struct bio *);
460
461extern int submit_bio_wait(struct bio *bio);
462extern void bio_advance(struct bio *, unsigned);
463
464extern void bio_init(struct bio *bio, struct bio_vec *table,
465 unsigned short max_vecs);
466extern void bio_uninit(struct bio *);
467extern void bio_reset(struct bio *);
468void bio_chain(struct bio *, struct bio *);
469
470extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
471extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
472 unsigned int, unsigned int);
473int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter);
474struct rq_map_data;
475extern struct bio *bio_map_user_iov(struct request_queue *,
476 struct iov_iter *, gfp_t);
477extern void bio_unmap_user(struct bio *);
478extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
479 gfp_t);
480extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
481 gfp_t, int);
482extern void bio_set_pages_dirty(struct bio *bio);
483extern void bio_check_pages_dirty(struct bio *bio);
484
485void generic_start_io_acct(struct request_queue *q, int rw,
486 unsigned long sectors, struct hd_struct *part);
487void generic_end_io_acct(struct request_queue *q, int rw,
488 struct hd_struct *part,
489 unsigned long start_time);
490
491#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
492# error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
493#endif
494#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
495extern void bio_flush_dcache_pages(struct bio *bi);
496#else
497static inline void bio_flush_dcache_pages(struct bio *bi)
498{
499}
500#endif
501
502extern void bio_copy_data(struct bio *dst, struct bio *src);
503extern void bio_free_pages(struct bio *bio);
504
505extern struct bio *bio_copy_user_iov(struct request_queue *,
506 struct rq_map_data *,
507 struct iov_iter *,
508 gfp_t);
509extern int bio_uncopy_user(struct bio *);
510void zero_fill_bio(struct bio *bio);
511extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *);
512extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int);
513extern unsigned int bvec_nr_vecs(unsigned short idx);
514
515#define bio_set_dev(bio, bdev) \
516do { \
517 if ((bio)->bi_disk != (bdev)->bd_disk) \
518 bio_clear_flag(bio, BIO_THROTTLED);\
519 (bio)->bi_disk = (bdev)->bd_disk; \
520 (bio)->bi_partno = (bdev)->bd_partno; \
521} while (0)
522
523#define bio_copy_dev(dst, src) \
524do { \
525 (dst)->bi_disk = (src)->bi_disk; \
526 (dst)->bi_partno = (src)->bi_partno; \
527} while (0)
528
529#define bio_dev(bio) \
530 disk_devt((bio)->bi_disk)
531
532#define bio_devname(bio, buf) \
533 __bdevname(bio_dev(bio), (buf))
534
535#ifdef CONFIG_BLK_CGROUP
536int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css);
537void bio_disassociate_task(struct bio *bio);
538void bio_clone_blkcg_association(struct bio *dst, struct bio *src);
539#else /* CONFIG_BLK_CGROUP */
540static inline int bio_associate_blkcg(struct bio *bio,
541 struct cgroup_subsys_state *blkcg_css) { return 0; }
542static inline void bio_disassociate_task(struct bio *bio) { }
543static inline void bio_clone_blkcg_association(struct bio *dst,
544 struct bio *src) { }
545#endif /* CONFIG_BLK_CGROUP */
546
547#ifdef CONFIG_HIGHMEM
548/*
549 * remember never ever reenable interrupts between a bvec_kmap_irq and
550 * bvec_kunmap_irq!
551 */
552static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
553{
554 unsigned long addr;
555
556 /*
557 * might not be a highmem page, but the preempt/irq count
558 * balancing is a lot nicer this way
559 */
560 local_irq_save(*flags);
561 addr = (unsigned long) kmap_atomic(bvec->bv_page);
562
563 BUG_ON(addr & ~PAGE_MASK);
564
565 return (char *) addr + bvec->bv_offset;
566}
567
568static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
569{
570 unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
571
572 kunmap_atomic((void *) ptr);
573 local_irq_restore(*flags);
574}
575
576#else
577static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
578{
579 return page_address(bvec->bv_page) + bvec->bv_offset;
580}
581
582static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
583{
584 *flags = 0;
585}
586#endif
587
588/*
589 * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
590 *
591 * A bio_list anchors a singly-linked list of bios chained through the bi_next
592 * member of the bio. The bio_list also caches the last list member to allow
593 * fast access to the tail.
594 */
595struct bio_list {
596 struct bio *head;
597 struct bio *tail;
598};
599
600static inline int bio_list_empty(const struct bio_list *bl)
601{
602 return bl->head == NULL;
603}
604
605static inline void bio_list_init(struct bio_list *bl)
606{
607 bl->head = bl->tail = NULL;
608}
609
610#define BIO_EMPTY_LIST { NULL, NULL }
611
612#define bio_list_for_each(bio, bl) \
613 for (bio = (bl)->head; bio; bio = bio->bi_next)
614
615static inline unsigned bio_list_size(const struct bio_list *bl)
616{
617 unsigned sz = 0;
618 struct bio *bio;
619
620 bio_list_for_each(bio, bl)
621 sz++;
622
623 return sz;
624}
625
626static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
627{
628 bio->bi_next = NULL;
629
630 if (bl->tail)
631 bl->tail->bi_next = bio;
632 else
633 bl->head = bio;
634
635 bl->tail = bio;
636}
637
638static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
639{
640 bio->bi_next = bl->head;
641
642 bl->head = bio;
643
644 if (!bl->tail)
645 bl->tail = bio;
646}
647
648static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
649{
650 if (!bl2->head)
651 return;
652
653 if (bl->tail)
654 bl->tail->bi_next = bl2->head;
655 else
656 bl->head = bl2->head;
657
658 bl->tail = bl2->tail;
659}
660
661static inline void bio_list_merge_head(struct bio_list *bl,
662 struct bio_list *bl2)
663{
664 if (!bl2->head)
665 return;
666
667 if (bl->head)
668 bl2->tail->bi_next = bl->head;
669 else
670 bl->tail = bl2->tail;
671
672 bl->head = bl2->head;
673}
674
675static inline struct bio *bio_list_peek(struct bio_list *bl)
676{
677 return bl->head;
678}
679
680static inline struct bio *bio_list_pop(struct bio_list *bl)
681{
682 struct bio *bio = bl->head;
683
684 if (bio) {
685 bl->head = bl->head->bi_next;
686 if (!bl->head)
687 bl->tail = NULL;
688
689 bio->bi_next = NULL;
690 }
691
692 return bio;
693}
694
695static inline struct bio *bio_list_get(struct bio_list *bl)
696{
697 struct bio *bio = bl->head;
698
699 bl->head = bl->tail = NULL;
700
701 return bio;
702}
703
704/*
705 * Increment chain count for the bio. Make sure the CHAIN flag update
706 * is visible before the raised count.
707 */
708static inline void bio_inc_remaining(struct bio *bio)
709{
710 bio_set_flag(bio, BIO_CHAIN);
711 smp_mb__before_atomic();
712 atomic_inc(&bio->__bi_remaining);
713}
714
715/*
716 * bio_set is used to allow other portions of the IO system to
717 * allocate their own private memory pools for bio and iovec structures.
718 * These memory pools in turn all allocate from the bio_slab
719 * and the bvec_slabs[].
720 */
721#define BIO_POOL_SIZE 2
722
723struct bio_set {
724 struct kmem_cache *bio_slab;
725 unsigned int front_pad;
726
727 mempool_t *bio_pool;
728 mempool_t *bvec_pool;
729#if defined(CONFIG_BLK_DEV_INTEGRITY)
730 mempool_t *bio_integrity_pool;
731 mempool_t *bvec_integrity_pool;
732#endif
733
734 /*
735 * Deadlock avoidance for stacking block drivers: see comments in
736 * bio_alloc_bioset() for details
737 */
738 spinlock_t rescue_lock;
739 struct bio_list rescue_list;
740 struct work_struct rescue_work;
741 struct workqueue_struct *rescue_workqueue;
742};
743
744struct biovec_slab {
745 int nr_vecs;
746 char *name;
747 struct kmem_cache *slab;
748};
749
750/*
751 * a small number of entries is fine, not going to be performance critical.
752 * basically we just need to survive
753 */
754#define BIO_SPLIT_ENTRIES 2
755
756#if defined(CONFIG_BLK_DEV_INTEGRITY)
757
758#define bip_for_each_vec(bvl, bip, iter) \
759 for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
760
761#define bio_for_each_integrity_vec(_bvl, _bio, _iter) \
762 for_each_bio(_bio) \
763 bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
764
765extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
766extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
767extern bool bio_integrity_prep(struct bio *);
768extern void bio_integrity_advance(struct bio *, unsigned int);
769extern void bio_integrity_trim(struct bio *);
770extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t);
771extern int bioset_integrity_create(struct bio_set *, int);
772extern void bioset_integrity_free(struct bio_set *);
773extern void bio_integrity_init(void);
774
775#else /* CONFIG_BLK_DEV_INTEGRITY */
776
777static inline void *bio_integrity(struct bio *bio)
778{
779 return NULL;
780}
781
782static inline int bioset_integrity_create(struct bio_set *bs, int pool_size)
783{
784 return 0;
785}
786
787static inline void bioset_integrity_free (struct bio_set *bs)
788{
789 return;
790}
791
792static inline bool bio_integrity_prep(struct bio *bio)
793{
794 return true;
795}
796
797static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
798 gfp_t gfp_mask)
799{
800 return 0;
801}
802
803static inline void bio_integrity_advance(struct bio *bio,
804 unsigned int bytes_done)
805{
806 return;
807}
808
809static inline void bio_integrity_trim(struct bio *bio)
810{
811 return;
812}
813
814static inline void bio_integrity_init(void)
815{
816 return;
817}
818
819static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
820{
821 return false;
822}
823
824static inline void *bio_integrity_alloc(struct bio * bio, gfp_t gfp,
825 unsigned int nr)
826{
827 return ERR_PTR(-EINVAL);
828}
829
830static inline int bio_integrity_add_page(struct bio *bio, struct page *page,
831 unsigned int len, unsigned int offset)
832{
833 return 0;
834}
835
836#endif /* CONFIG_BLK_DEV_INTEGRITY */
837
838#endif /* CONFIG_BLOCK */
839#endif /* __LINUX_BIO_H */