Linux kernel mirror (for testing)
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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
71#define bvec_iter_sectors(iter) ((iter).bi_size >> 9)
72#define bvec_iter_end_sector(iter) ((iter).bi_sector + bvec_iter_sectors((iter)))
73
74#define bio_sectors(bio) bvec_iter_sectors((bio)->bi_iter)
75#define bio_end_sector(bio) bvec_iter_end_sector((bio)->bi_iter)
76
77/*
78 * Return the data direction, READ or WRITE.
79 */
80#define bio_data_dir(bio) \
81 (op_is_write(bio_op(bio)) ? WRITE : READ)
82
83/*
84 * Check whether this bio carries any data or not. A NULL bio is allowed.
85 */
86static inline bool bio_has_data(struct bio *bio)
87{
88 if (bio &&
89 bio->bi_iter.bi_size &&
90 bio_op(bio) != REQ_OP_DISCARD &&
91 bio_op(bio) != REQ_OP_SECURE_ERASE &&
92 bio_op(bio) != REQ_OP_WRITE_ZEROES)
93 return true;
94
95 return false;
96}
97
98static inline bool bio_no_advance_iter(struct bio *bio)
99{
100 return bio_op(bio) == REQ_OP_DISCARD ||
101 bio_op(bio) == REQ_OP_SECURE_ERASE ||
102 bio_op(bio) == REQ_OP_WRITE_SAME ||
103 bio_op(bio) == REQ_OP_WRITE_ZEROES;
104}
105
106static inline bool bio_mergeable(struct bio *bio)
107{
108 if (bio->bi_opf & REQ_NOMERGE_FLAGS)
109 return false;
110
111 return true;
112}
113
114static inline unsigned int bio_cur_bytes(struct bio *bio)
115{
116 if (bio_has_data(bio))
117 return bio_iovec(bio).bv_len;
118 else /* dataless requests such as discard */
119 return bio->bi_iter.bi_size;
120}
121
122static inline void *bio_data(struct bio *bio)
123{
124 if (bio_has_data(bio))
125 return page_address(bio_page(bio)) + bio_offset(bio);
126
127 return NULL;
128}
129
130static inline bool bio_full(struct bio *bio)
131{
132 return bio->bi_vcnt >= bio->bi_max_vecs;
133}
134
135/*
136 * will die
137 */
138#define bvec_to_phys(bv) (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
139
140/*
141 * merge helpers etc
142 */
143
144/* Default implementation of BIOVEC_PHYS_MERGEABLE */
145#define __BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
146 ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
147
148/*
149 * allow arch override, for eg virtualized architectures (put in asm/io.h)
150 */
151#ifndef BIOVEC_PHYS_MERGEABLE
152#define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
153 __BIOVEC_PHYS_MERGEABLE(vec1, vec2)
154#endif
155
156#define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
157 (((addr1) | (mask)) == (((addr2) - 1) | (mask)))
158#define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
159 __BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q)))
160
161/*
162 * drivers should _never_ use the all version - the bio may have been split
163 * before it got to the driver and the driver won't own all of it
164 */
165#define bio_for_each_segment_all(bvl, bio, i) \
166 for (i = 0, bvl = (bio)->bi_io_vec; i < (bio)->bi_vcnt; i++, bvl++)
167
168static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter,
169 unsigned bytes)
170{
171 iter->bi_sector += bytes >> 9;
172
173 if (bio_no_advance_iter(bio)) {
174 iter->bi_size -= bytes;
175 iter->bi_done += bytes;
176 } else {
177 bvec_iter_advance(bio->bi_io_vec, iter, bytes);
178 /* TODO: It is reasonable to complete bio with error here. */
179 }
180}
181
182static inline bool bio_rewind_iter(struct bio *bio, struct bvec_iter *iter,
183 unsigned int bytes)
184{
185 iter->bi_sector -= bytes >> 9;
186
187 if (bio_no_advance_iter(bio)) {
188 iter->bi_size += bytes;
189 iter->bi_done -= bytes;
190 return true;
191 }
192
193 return bvec_iter_rewind(bio->bi_io_vec, iter, bytes);
194}
195
196#define __bio_for_each_segment(bvl, bio, iter, start) \
197 for (iter = (start); \
198 (iter).bi_size && \
199 ((bvl = bio_iter_iovec((bio), (iter))), 1); \
200 bio_advance_iter((bio), &(iter), (bvl).bv_len))
201
202#define bio_for_each_segment(bvl, bio, iter) \
203 __bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter)
204
205#define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)
206
207static inline unsigned bio_segments(struct bio *bio)
208{
209 unsigned segs = 0;
210 struct bio_vec bv;
211 struct bvec_iter iter;
212
213 /*
214 * We special case discard/write same/write zeroes, because they
215 * interpret bi_size differently:
216 */
217
218 switch (bio_op(bio)) {
219 case REQ_OP_DISCARD:
220 case REQ_OP_SECURE_ERASE:
221 case REQ_OP_WRITE_ZEROES:
222 return 0;
223 case REQ_OP_WRITE_SAME:
224 return 1;
225 default:
226 break;
227 }
228
229 bio_for_each_segment(bv, bio, iter)
230 segs++;
231
232 return segs;
233}
234
235/*
236 * get a reference to a bio, so it won't disappear. the intended use is
237 * something like:
238 *
239 * bio_get(bio);
240 * submit_bio(rw, bio);
241 * if (bio->bi_flags ...)
242 * do_something
243 * bio_put(bio);
244 *
245 * without the bio_get(), it could potentially complete I/O before submit_bio
246 * returns. and then bio would be freed memory when if (bio->bi_flags ...)
247 * runs
248 */
249static inline void bio_get(struct bio *bio)
250{
251 bio->bi_flags |= (1 << BIO_REFFED);
252 smp_mb__before_atomic();
253 atomic_inc(&bio->__bi_cnt);
254}
255
256static inline void bio_cnt_set(struct bio *bio, unsigned int count)
257{
258 if (count != 1) {
259 bio->bi_flags |= (1 << BIO_REFFED);
260 smp_mb__before_atomic();
261 }
262 atomic_set(&bio->__bi_cnt, count);
263}
264
265static inline bool bio_flagged(struct bio *bio, unsigned int bit)
266{
267 return (bio->bi_flags & (1U << bit)) != 0;
268}
269
270static inline void bio_set_flag(struct bio *bio, unsigned int bit)
271{
272 bio->bi_flags |= (1U << bit);
273}
274
275static inline void bio_clear_flag(struct bio *bio, unsigned int bit)
276{
277 bio->bi_flags &= ~(1U << bit);
278}
279
280static inline void bio_get_first_bvec(struct bio *bio, struct bio_vec *bv)
281{
282 *bv = bio_iovec(bio);
283}
284
285static inline void bio_get_last_bvec(struct bio *bio, struct bio_vec *bv)
286{
287 struct bvec_iter iter = bio->bi_iter;
288 int idx;
289
290 if (unlikely(!bio_multiple_segments(bio))) {
291 *bv = bio_iovec(bio);
292 return;
293 }
294
295 bio_advance_iter(bio, &iter, iter.bi_size);
296
297 if (!iter.bi_bvec_done)
298 idx = iter.bi_idx - 1;
299 else /* in the middle of bvec */
300 idx = iter.bi_idx;
301
302 *bv = bio->bi_io_vec[idx];
303
304 /*
305 * iter.bi_bvec_done records actual length of the last bvec
306 * if this bio ends in the middle of one io vector
307 */
308 if (iter.bi_bvec_done)
309 bv->bv_len = iter.bi_bvec_done;
310}
311
312static inline unsigned bio_pages_all(struct bio *bio)
313{
314 WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
315 return bio->bi_vcnt;
316}
317
318static inline struct bio_vec *bio_first_bvec_all(struct bio *bio)
319{
320 WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
321 return bio->bi_io_vec;
322}
323
324static inline struct page *bio_first_page_all(struct bio *bio)
325{
326 return bio_first_bvec_all(bio)->bv_page;
327}
328
329static inline struct bio_vec *bio_last_bvec_all(struct bio *bio)
330{
331 WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
332 return &bio->bi_io_vec[bio->bi_vcnt - 1];
333}
334
335enum bip_flags {
336 BIP_BLOCK_INTEGRITY = 1 << 0, /* block layer owns integrity data */
337 BIP_MAPPED_INTEGRITY = 1 << 1, /* ref tag has been remapped */
338 BIP_CTRL_NOCHECK = 1 << 2, /* disable HBA integrity checking */
339 BIP_DISK_NOCHECK = 1 << 3, /* disable disk integrity checking */
340 BIP_IP_CHECKSUM = 1 << 4, /* IP checksum */
341};
342
343/*
344 * bio integrity payload
345 */
346struct bio_integrity_payload {
347 struct bio *bip_bio; /* parent bio */
348
349 struct bvec_iter bip_iter;
350
351 unsigned short bip_slab; /* slab the bip came from */
352 unsigned short bip_vcnt; /* # of integrity bio_vecs */
353 unsigned short bip_max_vcnt; /* integrity bio_vec slots */
354 unsigned short bip_flags; /* control flags */
355
356 struct work_struct bip_work; /* I/O completion */
357
358 struct bio_vec *bip_vec;
359 struct bio_vec bip_inline_vecs[0];/* embedded bvec array */
360};
361
362#if defined(CONFIG_BLK_DEV_INTEGRITY)
363
364static inline struct bio_integrity_payload *bio_integrity(struct bio *bio)
365{
366 if (bio->bi_opf & REQ_INTEGRITY)
367 return bio->bi_integrity;
368
369 return NULL;
370}
371
372static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
373{
374 struct bio_integrity_payload *bip = bio_integrity(bio);
375
376 if (bip)
377 return bip->bip_flags & flag;
378
379 return false;
380}
381
382static inline sector_t bip_get_seed(struct bio_integrity_payload *bip)
383{
384 return bip->bip_iter.bi_sector;
385}
386
387static inline void bip_set_seed(struct bio_integrity_payload *bip,
388 sector_t seed)
389{
390 bip->bip_iter.bi_sector = seed;
391}
392
393#endif /* CONFIG_BLK_DEV_INTEGRITY */
394
395extern void bio_trim(struct bio *bio, int offset, int size);
396extern struct bio *bio_split(struct bio *bio, int sectors,
397 gfp_t gfp, struct bio_set *bs);
398
399/**
400 * bio_next_split - get next @sectors from a bio, splitting if necessary
401 * @bio: bio to split
402 * @sectors: number of sectors to split from the front of @bio
403 * @gfp: gfp mask
404 * @bs: bio set to allocate from
405 *
406 * Returns a bio representing the next @sectors of @bio - if the bio is smaller
407 * than @sectors, returns the original bio unchanged.
408 */
409static inline struct bio *bio_next_split(struct bio *bio, int sectors,
410 gfp_t gfp, struct bio_set *bs)
411{
412 if (sectors >= bio_sectors(bio))
413 return bio;
414
415 return bio_split(bio, sectors, gfp, bs);
416}
417
418enum {
419 BIOSET_NEED_BVECS = BIT(0),
420 BIOSET_NEED_RESCUER = BIT(1),
421};
422extern int bioset_init(struct bio_set *, unsigned int, unsigned int, int flags);
423extern void bioset_exit(struct bio_set *);
424extern int biovec_init_pool(mempool_t *pool, int pool_entries);
425extern int bioset_init_from_src(struct bio_set *bs, struct bio_set *src);
426
427extern struct bio *bio_alloc_bioset(gfp_t, unsigned int, struct bio_set *);
428extern void bio_put(struct bio *);
429
430extern void __bio_clone_fast(struct bio *, struct bio *);
431extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *);
432extern struct bio *bio_clone_bioset(struct bio *, gfp_t, struct bio_set *bs);
433
434extern struct bio_set fs_bio_set;
435
436static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
437{
438 return bio_alloc_bioset(gfp_mask, nr_iovecs, &fs_bio_set);
439}
440
441static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
442{
443 return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
444}
445
446static inline struct bio *bio_clone_kmalloc(struct bio *bio, gfp_t gfp_mask)
447{
448 return bio_clone_bioset(bio, gfp_mask, NULL);
449
450}
451
452extern blk_qc_t submit_bio(struct bio *);
453
454extern void bio_endio(struct bio *);
455
456static inline void bio_io_error(struct bio *bio)
457{
458 bio->bi_status = BLK_STS_IOERR;
459 bio_endio(bio);
460}
461
462static inline void bio_wouldblock_error(struct bio *bio)
463{
464 bio->bi_status = BLK_STS_AGAIN;
465 bio_endio(bio);
466}
467
468struct request_queue;
469extern int bio_phys_segments(struct request_queue *, struct bio *);
470
471extern int submit_bio_wait(struct bio *bio);
472extern void bio_advance(struct bio *, unsigned);
473
474extern void bio_init(struct bio *bio, struct bio_vec *table,
475 unsigned short max_vecs);
476extern void bio_uninit(struct bio *);
477extern void bio_reset(struct bio *);
478void bio_chain(struct bio *, struct bio *);
479
480extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
481extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
482 unsigned int, unsigned int);
483bool __bio_try_merge_page(struct bio *bio, struct page *page,
484 unsigned int len, unsigned int off);
485void __bio_add_page(struct bio *bio, struct page *page,
486 unsigned int len, unsigned int off);
487int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter);
488struct rq_map_data;
489extern struct bio *bio_map_user_iov(struct request_queue *,
490 struct iov_iter *, gfp_t);
491extern void bio_unmap_user(struct bio *);
492extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
493 gfp_t);
494extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
495 gfp_t, int);
496extern void bio_set_pages_dirty(struct bio *bio);
497extern void bio_check_pages_dirty(struct bio *bio);
498
499void generic_start_io_acct(struct request_queue *q, int rw,
500 unsigned long sectors, struct hd_struct *part);
501void generic_end_io_acct(struct request_queue *q, int rw,
502 struct hd_struct *part,
503 unsigned long start_time);
504
505#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
506# error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
507#endif
508#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
509extern void bio_flush_dcache_pages(struct bio *bi);
510#else
511static inline void bio_flush_dcache_pages(struct bio *bi)
512{
513}
514#endif
515
516extern void bio_copy_data_iter(struct bio *dst, struct bvec_iter *dst_iter,
517 struct bio *src, struct bvec_iter *src_iter);
518extern void bio_copy_data(struct bio *dst, struct bio *src);
519extern void bio_list_copy_data(struct bio *dst, struct bio *src);
520extern void bio_free_pages(struct bio *bio);
521
522extern struct bio *bio_copy_user_iov(struct request_queue *,
523 struct rq_map_data *,
524 struct iov_iter *,
525 gfp_t);
526extern int bio_uncopy_user(struct bio *);
527void zero_fill_bio_iter(struct bio *bio, struct bvec_iter iter);
528
529static inline void zero_fill_bio(struct bio *bio)
530{
531 zero_fill_bio_iter(bio, bio->bi_iter);
532}
533
534extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *);
535extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int);
536extern unsigned int bvec_nr_vecs(unsigned short idx);
537extern const char *bio_devname(struct bio *bio, char *buffer);
538
539#define bio_set_dev(bio, bdev) \
540do { \
541 if ((bio)->bi_disk != (bdev)->bd_disk) \
542 bio_clear_flag(bio, BIO_THROTTLED);\
543 (bio)->bi_disk = (bdev)->bd_disk; \
544 (bio)->bi_partno = (bdev)->bd_partno; \
545} while (0)
546
547#define bio_copy_dev(dst, src) \
548do { \
549 (dst)->bi_disk = (src)->bi_disk; \
550 (dst)->bi_partno = (src)->bi_partno; \
551} while (0)
552
553#define bio_dev(bio) \
554 disk_devt((bio)->bi_disk)
555
556#ifdef CONFIG_BLK_CGROUP
557int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css);
558void bio_disassociate_task(struct bio *bio);
559void bio_clone_blkcg_association(struct bio *dst, struct bio *src);
560#else /* CONFIG_BLK_CGROUP */
561static inline int bio_associate_blkcg(struct bio *bio,
562 struct cgroup_subsys_state *blkcg_css) { return 0; }
563static inline void bio_disassociate_task(struct bio *bio) { }
564static inline void bio_clone_blkcg_association(struct bio *dst,
565 struct bio *src) { }
566#endif /* CONFIG_BLK_CGROUP */
567
568#ifdef CONFIG_HIGHMEM
569/*
570 * remember never ever reenable interrupts between a bvec_kmap_irq and
571 * bvec_kunmap_irq!
572 */
573static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
574{
575 unsigned long addr;
576
577 /*
578 * might not be a highmem page, but the preempt/irq count
579 * balancing is a lot nicer this way
580 */
581 local_irq_save(*flags);
582 addr = (unsigned long) kmap_atomic(bvec->bv_page);
583
584 BUG_ON(addr & ~PAGE_MASK);
585
586 return (char *) addr + bvec->bv_offset;
587}
588
589static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
590{
591 unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
592
593 kunmap_atomic((void *) ptr);
594 local_irq_restore(*flags);
595}
596
597#else
598static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
599{
600 return page_address(bvec->bv_page) + bvec->bv_offset;
601}
602
603static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
604{
605 *flags = 0;
606}
607#endif
608
609/*
610 * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
611 *
612 * A bio_list anchors a singly-linked list of bios chained through the bi_next
613 * member of the bio. The bio_list also caches the last list member to allow
614 * fast access to the tail.
615 */
616struct bio_list {
617 struct bio *head;
618 struct bio *tail;
619};
620
621static inline int bio_list_empty(const struct bio_list *bl)
622{
623 return bl->head == NULL;
624}
625
626static inline void bio_list_init(struct bio_list *bl)
627{
628 bl->head = bl->tail = NULL;
629}
630
631#define BIO_EMPTY_LIST { NULL, NULL }
632
633#define bio_list_for_each(bio, bl) \
634 for (bio = (bl)->head; bio; bio = bio->bi_next)
635
636static inline unsigned bio_list_size(const struct bio_list *bl)
637{
638 unsigned sz = 0;
639 struct bio *bio;
640
641 bio_list_for_each(bio, bl)
642 sz++;
643
644 return sz;
645}
646
647static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
648{
649 bio->bi_next = NULL;
650
651 if (bl->tail)
652 bl->tail->bi_next = bio;
653 else
654 bl->head = bio;
655
656 bl->tail = bio;
657}
658
659static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
660{
661 bio->bi_next = bl->head;
662
663 bl->head = bio;
664
665 if (!bl->tail)
666 bl->tail = bio;
667}
668
669static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
670{
671 if (!bl2->head)
672 return;
673
674 if (bl->tail)
675 bl->tail->bi_next = bl2->head;
676 else
677 bl->head = bl2->head;
678
679 bl->tail = bl2->tail;
680}
681
682static inline void bio_list_merge_head(struct bio_list *bl,
683 struct bio_list *bl2)
684{
685 if (!bl2->head)
686 return;
687
688 if (bl->head)
689 bl2->tail->bi_next = bl->head;
690 else
691 bl->tail = bl2->tail;
692
693 bl->head = bl2->head;
694}
695
696static inline struct bio *bio_list_peek(struct bio_list *bl)
697{
698 return bl->head;
699}
700
701static inline struct bio *bio_list_pop(struct bio_list *bl)
702{
703 struct bio *bio = bl->head;
704
705 if (bio) {
706 bl->head = bl->head->bi_next;
707 if (!bl->head)
708 bl->tail = NULL;
709
710 bio->bi_next = NULL;
711 }
712
713 return bio;
714}
715
716static inline struct bio *bio_list_get(struct bio_list *bl)
717{
718 struct bio *bio = bl->head;
719
720 bl->head = bl->tail = NULL;
721
722 return bio;
723}
724
725/*
726 * Increment chain count for the bio. Make sure the CHAIN flag update
727 * is visible before the raised count.
728 */
729static inline void bio_inc_remaining(struct bio *bio)
730{
731 bio_set_flag(bio, BIO_CHAIN);
732 smp_mb__before_atomic();
733 atomic_inc(&bio->__bi_remaining);
734}
735
736/*
737 * bio_set is used to allow other portions of the IO system to
738 * allocate their own private memory pools for bio and iovec structures.
739 * These memory pools in turn all allocate from the bio_slab
740 * and the bvec_slabs[].
741 */
742#define BIO_POOL_SIZE 2
743
744struct bio_set {
745 struct kmem_cache *bio_slab;
746 unsigned int front_pad;
747
748 mempool_t bio_pool;
749 mempool_t bvec_pool;
750#if defined(CONFIG_BLK_DEV_INTEGRITY)
751 mempool_t bio_integrity_pool;
752 mempool_t bvec_integrity_pool;
753#endif
754
755 /*
756 * Deadlock avoidance for stacking block drivers: see comments in
757 * bio_alloc_bioset() for details
758 */
759 spinlock_t rescue_lock;
760 struct bio_list rescue_list;
761 struct work_struct rescue_work;
762 struct workqueue_struct *rescue_workqueue;
763};
764
765struct biovec_slab {
766 int nr_vecs;
767 char *name;
768 struct kmem_cache *slab;
769};
770
771static inline bool bioset_initialized(struct bio_set *bs)
772{
773 return bs->bio_slab != NULL;
774}
775
776/*
777 * a small number of entries is fine, not going to be performance critical.
778 * basically we just need to survive
779 */
780#define BIO_SPLIT_ENTRIES 2
781
782#if defined(CONFIG_BLK_DEV_INTEGRITY)
783
784#define bip_for_each_vec(bvl, bip, iter) \
785 for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
786
787#define bio_for_each_integrity_vec(_bvl, _bio, _iter) \
788 for_each_bio(_bio) \
789 bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
790
791extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
792extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
793extern bool bio_integrity_prep(struct bio *);
794extern void bio_integrity_advance(struct bio *, unsigned int);
795extern void bio_integrity_trim(struct bio *);
796extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t);
797extern int bioset_integrity_create(struct bio_set *, int);
798extern void bioset_integrity_free(struct bio_set *);
799extern void bio_integrity_init(void);
800
801#else /* CONFIG_BLK_DEV_INTEGRITY */
802
803static inline void *bio_integrity(struct bio *bio)
804{
805 return NULL;
806}
807
808static inline int bioset_integrity_create(struct bio_set *bs, int pool_size)
809{
810 return 0;
811}
812
813static inline void bioset_integrity_free (struct bio_set *bs)
814{
815 return;
816}
817
818static inline bool bio_integrity_prep(struct bio *bio)
819{
820 return true;
821}
822
823static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
824 gfp_t gfp_mask)
825{
826 return 0;
827}
828
829static inline void bio_integrity_advance(struct bio *bio,
830 unsigned int bytes_done)
831{
832 return;
833}
834
835static inline void bio_integrity_trim(struct bio *bio)
836{
837 return;
838}
839
840static inline void bio_integrity_init(void)
841{
842 return;
843}
844
845static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
846{
847 return false;
848}
849
850static inline void *bio_integrity_alloc(struct bio * bio, gfp_t gfp,
851 unsigned int nr)
852{
853 return ERR_PTR(-EINVAL);
854}
855
856static inline int bio_integrity_add_page(struct bio *bio, struct page *page,
857 unsigned int len, unsigned int offset)
858{
859 return 0;
860}
861
862#endif /* CONFIG_BLK_DEV_INTEGRITY */
863
864#endif /* CONFIG_BLOCK */
865#endif /* __LINUX_BIO_H */