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