xref: /linux-6.15/include/linux/bio.h (revision 8fc07ebe)
1 /*
2  * 2.5 block I/O model
3  *
4  * Copyright (C) 2001 Jens Axboe <[email protected]>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  *
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public Licens
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-
19  */
20 #ifndef __LINUX_BIO_H
21 #define __LINUX_BIO_H
22 
23 #include <linux/highmem.h>
24 #include <linux/mempool.h>
25 #include <linux/ioprio.h>
26 #include <linux/bug.h>
27 
28 #ifdef CONFIG_BLOCK
29 
30 #include <asm/io.h>
31 
32 /* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */
33 #include <linux/blk_types.h>
34 
35 #define BIO_DEBUG
36 
37 #ifdef BIO_DEBUG
38 #define BIO_BUG_ON	BUG_ON
39 #else
40 #define BIO_BUG_ON
41 #endif
42 
43 #define BIO_MAX_PAGES		256
44 
45 #define bio_prio(bio)			(bio)->bi_ioprio
46 #define bio_set_prio(bio, prio)		((bio)->bi_ioprio = prio)
47 
48 #define bio_iter_iovec(bio, iter)				\
49 	bvec_iter_bvec((bio)->bi_io_vec, (iter))
50 
51 #define bio_iter_page(bio, iter)				\
52 	bvec_iter_page((bio)->bi_io_vec, (iter))
53 #define bio_iter_len(bio, iter)					\
54 	bvec_iter_len((bio)->bi_io_vec, (iter))
55 #define bio_iter_offset(bio, iter)				\
56 	bvec_iter_offset((bio)->bi_io_vec, (iter))
57 
58 #define bio_page(bio)		bio_iter_page((bio), (bio)->bi_iter)
59 #define bio_offset(bio)		bio_iter_offset((bio), (bio)->bi_iter)
60 #define bio_iovec(bio)		bio_iter_iovec((bio), (bio)->bi_iter)
61 
62 #define bio_multiple_segments(bio)				\
63 	((bio)->bi_iter.bi_size != bio_iovec(bio).bv_len)
64 #define bio_sectors(bio)	((bio)->bi_iter.bi_size >> 9)
65 #define bio_end_sector(bio)	((bio)->bi_iter.bi_sector + bio_sectors((bio)))
66 
67 /*
68  * Check whether this bio carries any data or not. A NULL bio is allowed.
69  */
70 static inline bool bio_has_data(struct bio *bio)
71 {
72 	if (bio &&
73 	    bio->bi_iter.bi_size &&
74 	    bio_op(bio) != REQ_OP_DISCARD)
75 		return true;
76 
77 	return false;
78 }
79 
80 static inline bool bio_no_advance_iter(struct bio *bio)
81 {
82 	return bio_op(bio) == REQ_OP_DISCARD || bio_op(bio) == REQ_OP_WRITE_SAME;
83 }
84 
85 static inline bool bio_is_rw(struct bio *bio)
86 {
87 	if (!bio_has_data(bio))
88 		return false;
89 
90 	if (bio_no_advance_iter(bio))
91 		return false;
92 
93 	return true;
94 }
95 
96 static inline bool bio_mergeable(struct bio *bio)
97 {
98 	if (bio->bi_opf & REQ_NOMERGE_FLAGS)
99 		return false;
100 
101 	return true;
102 }
103 
104 static inline unsigned int bio_cur_bytes(struct bio *bio)
105 {
106 	if (bio_has_data(bio))
107 		return bio_iovec(bio).bv_len;
108 	else /* dataless requests such as discard */
109 		return bio->bi_iter.bi_size;
110 }
111 
112 static inline void *bio_data(struct bio *bio)
113 {
114 	if (bio_has_data(bio))
115 		return page_address(bio_page(bio)) + bio_offset(bio);
116 
117 	return NULL;
118 }
119 
120 /*
121  * will die
122  */
123 #define bio_to_phys(bio)	(page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
124 #define bvec_to_phys(bv)	(page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
125 
126 /*
127  * queues that have highmem support enabled may still need to revert to
128  * PIO transfers occasionally and thus map high pages temporarily. For
129  * permanent PIO fall back, user is probably better off disabling highmem
130  * I/O completely on that queue (see ide-dma for example)
131  */
132 #define __bio_kmap_atomic(bio, iter)				\
133 	(kmap_atomic(bio_iter_iovec((bio), (iter)).bv_page) +	\
134 		bio_iter_iovec((bio), (iter)).bv_offset)
135 
136 #define __bio_kunmap_atomic(addr)	kunmap_atomic(addr)
137 
138 /*
139  * merge helpers etc
140  */
141 
142 /* Default implementation of BIOVEC_PHYS_MERGEABLE */
143 #define __BIOVEC_PHYS_MERGEABLE(vec1, vec2)	\
144 	((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
145 
146 /*
147  * allow arch override, for eg virtualized architectures (put in asm/io.h)
148  */
149 #ifndef BIOVEC_PHYS_MERGEABLE
150 #define BIOVEC_PHYS_MERGEABLE(vec1, vec2)	\
151 	__BIOVEC_PHYS_MERGEABLE(vec1, vec2)
152 #endif
153 
154 #define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
155 	(((addr1) | (mask)) == (((addr2) - 1) | (mask)))
156 #define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
157 	__BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q)))
158 
159 /*
160  * drivers should _never_ use the all version - the bio may have been split
161  * before it got to the driver and the driver won't own all of it
162  */
163 #define bio_for_each_segment_all(bvl, bio, i)				\
164 	for (i = 0, bvl = (bio)->bi_io_vec; i < (bio)->bi_vcnt; i++, bvl++)
165 
166 static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter,
167 				    unsigned bytes)
168 {
169 	iter->bi_sector += bytes >> 9;
170 
171 	if (bio_no_advance_iter(bio))
172 		iter->bi_size -= bytes;
173 	else
174 		bvec_iter_advance(bio->bi_io_vec, iter, bytes);
175 }
176 
177 #define __bio_for_each_segment(bvl, bio, iter, start)			\
178 	for (iter = (start);						\
179 	     (iter).bi_size &&						\
180 		((bvl = bio_iter_iovec((bio), (iter))), 1);		\
181 	     bio_advance_iter((bio), &(iter), (bvl).bv_len))
182 
183 #define bio_for_each_segment(bvl, bio, iter)				\
184 	__bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter)
185 
186 #define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)
187 
188 static inline unsigned bio_segments(struct bio *bio)
189 {
190 	unsigned segs = 0;
191 	struct bio_vec bv;
192 	struct bvec_iter iter;
193 
194 	/*
195 	 * We special case discard/write same, because they interpret bi_size
196 	 * differently:
197 	 */
198 
199 	if (bio_op(bio) == REQ_OP_DISCARD)
200 		return 1;
201 
202 	if (bio_op(bio) == REQ_OP_WRITE_SAME)
203 		return 1;
204 
205 	bio_for_each_segment(bv, bio, iter)
206 		segs++;
207 
208 	return segs;
209 }
210 
211 /*
212  * get a reference to a bio, so it won't disappear. the intended use is
213  * something like:
214  *
215  * bio_get(bio);
216  * submit_bio(rw, bio);
217  * if (bio->bi_flags ...)
218  *	do_something
219  * bio_put(bio);
220  *
221  * without the bio_get(), it could potentially complete I/O before submit_bio
222  * returns. and then bio would be freed memory when if (bio->bi_flags ...)
223  * runs
224  */
225 static inline void bio_get(struct bio *bio)
226 {
227 	bio->bi_flags |= (1 << BIO_REFFED);
228 	smp_mb__before_atomic();
229 	atomic_inc(&bio->__bi_cnt);
230 }
231 
232 static inline void bio_cnt_set(struct bio *bio, unsigned int count)
233 {
234 	if (count != 1) {
235 		bio->bi_flags |= (1 << BIO_REFFED);
236 		smp_mb__before_atomic();
237 	}
238 	atomic_set(&bio->__bi_cnt, count);
239 }
240 
241 static inline bool bio_flagged(struct bio *bio, unsigned int bit)
242 {
243 	return (bio->bi_flags & (1U << bit)) != 0;
244 }
245 
246 static inline void bio_set_flag(struct bio *bio, unsigned int bit)
247 {
248 	bio->bi_flags |= (1U << bit);
249 }
250 
251 static inline void bio_clear_flag(struct bio *bio, unsigned int bit)
252 {
253 	bio->bi_flags &= ~(1U << bit);
254 }
255 
256 static inline void bio_get_first_bvec(struct bio *bio, struct bio_vec *bv)
257 {
258 	*bv = bio_iovec(bio);
259 }
260 
261 static inline void bio_get_last_bvec(struct bio *bio, struct bio_vec *bv)
262 {
263 	struct bvec_iter iter = bio->bi_iter;
264 	int idx;
265 
266 	if (unlikely(!bio_multiple_segments(bio))) {
267 		*bv = bio_iovec(bio);
268 		return;
269 	}
270 
271 	bio_advance_iter(bio, &iter, iter.bi_size);
272 
273 	if (!iter.bi_bvec_done)
274 		idx = iter.bi_idx - 1;
275 	else	/* in the middle of bvec */
276 		idx = iter.bi_idx;
277 
278 	*bv = bio->bi_io_vec[idx];
279 
280 	/*
281 	 * iter.bi_bvec_done records actual length of the last bvec
282 	 * if this bio ends in the middle of one io vector
283 	 */
284 	if (iter.bi_bvec_done)
285 		bv->bv_len = iter.bi_bvec_done;
286 }
287 
288 enum bip_flags {
289 	BIP_BLOCK_INTEGRITY	= 1 << 0, /* block layer owns integrity data */
290 	BIP_MAPPED_INTEGRITY	= 1 << 1, /* ref tag has been remapped */
291 	BIP_CTRL_NOCHECK	= 1 << 2, /* disable HBA integrity checking */
292 	BIP_DISK_NOCHECK	= 1 << 3, /* disable disk integrity checking */
293 	BIP_IP_CHECKSUM		= 1 << 4, /* IP checksum */
294 };
295 
296 /*
297  * bio integrity payload
298  */
299 struct bio_integrity_payload {
300 	struct bio		*bip_bio;	/* parent bio */
301 
302 	struct bvec_iter	bip_iter;
303 
304 	bio_end_io_t		*bip_end_io;	/* saved I/O completion fn */
305 
306 	unsigned short		bip_slab;	/* slab the bip came from */
307 	unsigned short		bip_vcnt;	/* # of integrity bio_vecs */
308 	unsigned short		bip_max_vcnt;	/* integrity bio_vec slots */
309 	unsigned short		bip_flags;	/* control flags */
310 
311 	struct work_struct	bip_work;	/* I/O completion */
312 
313 	struct bio_vec		*bip_vec;
314 	struct bio_vec		bip_inline_vecs[0];/* embedded bvec array */
315 };
316 
317 #if defined(CONFIG_BLK_DEV_INTEGRITY)
318 
319 static inline struct bio_integrity_payload *bio_integrity(struct bio *bio)
320 {
321 	if (bio->bi_opf & REQ_INTEGRITY)
322 		return bio->bi_integrity;
323 
324 	return NULL;
325 }
326 
327 static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
328 {
329 	struct bio_integrity_payload *bip = bio_integrity(bio);
330 
331 	if (bip)
332 		return bip->bip_flags & flag;
333 
334 	return false;
335 }
336 
337 static inline sector_t bip_get_seed(struct bio_integrity_payload *bip)
338 {
339 	return bip->bip_iter.bi_sector;
340 }
341 
342 static inline void bip_set_seed(struct bio_integrity_payload *bip,
343 				sector_t seed)
344 {
345 	bip->bip_iter.bi_sector = seed;
346 }
347 
348 #endif /* CONFIG_BLK_DEV_INTEGRITY */
349 
350 extern void bio_trim(struct bio *bio, int offset, int size);
351 extern struct bio *bio_split(struct bio *bio, int sectors,
352 			     gfp_t gfp, struct bio_set *bs);
353 
354 /**
355  * bio_next_split - get next @sectors from a bio, splitting if necessary
356  * @bio:	bio to split
357  * @sectors:	number of sectors to split from the front of @bio
358  * @gfp:	gfp mask
359  * @bs:		bio set to allocate from
360  *
361  * Returns a bio representing the next @sectors of @bio - if the bio is smaller
362  * than @sectors, returns the original bio unchanged.
363  */
364 static inline struct bio *bio_next_split(struct bio *bio, int sectors,
365 					 gfp_t gfp, struct bio_set *bs)
366 {
367 	if (sectors >= bio_sectors(bio))
368 		return bio;
369 
370 	return bio_split(bio, sectors, gfp, bs);
371 }
372 
373 extern struct bio_set *bioset_create(unsigned int, unsigned int);
374 extern struct bio_set *bioset_create_nobvec(unsigned int, unsigned int);
375 extern void bioset_free(struct bio_set *);
376 extern mempool_t *biovec_create_pool(int pool_entries);
377 
378 extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
379 extern void bio_put(struct bio *);
380 
381 extern void __bio_clone_fast(struct bio *, struct bio *);
382 extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *);
383 extern struct bio *bio_clone_bioset(struct bio *, gfp_t, struct bio_set *bs);
384 
385 extern struct bio_set *fs_bio_set;
386 
387 static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
388 {
389 	return bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set);
390 }
391 
392 static inline struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask)
393 {
394 	return bio_clone_bioset(bio, gfp_mask, fs_bio_set);
395 }
396 
397 static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
398 {
399 	return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
400 }
401 
402 static inline struct bio *bio_clone_kmalloc(struct bio *bio, gfp_t gfp_mask)
403 {
404 	return bio_clone_bioset(bio, gfp_mask, NULL);
405 
406 }
407 
408 extern void bio_endio(struct bio *);
409 
410 static inline void bio_io_error(struct bio *bio)
411 {
412 	bio->bi_error = -EIO;
413 	bio_endio(bio);
414 }
415 
416 struct request_queue;
417 extern int bio_phys_segments(struct request_queue *, struct bio *);
418 
419 extern int submit_bio_wait(struct bio *bio);
420 extern void bio_advance(struct bio *, unsigned);
421 
422 extern void bio_init(struct bio *);
423 extern void bio_reset(struct bio *);
424 void bio_chain(struct bio *, struct bio *);
425 
426 extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
427 extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
428 			   unsigned int, unsigned int);
429 struct rq_map_data;
430 extern struct bio *bio_map_user_iov(struct request_queue *,
431 				    const struct iov_iter *, gfp_t);
432 extern void bio_unmap_user(struct bio *);
433 extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
434 				gfp_t);
435 extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
436 				 gfp_t, int);
437 extern void bio_set_pages_dirty(struct bio *bio);
438 extern void bio_check_pages_dirty(struct bio *bio);
439 
440 void generic_start_io_acct(int rw, unsigned long sectors,
441 			   struct hd_struct *part);
442 void generic_end_io_acct(int rw, struct hd_struct *part,
443 			 unsigned long start_time);
444 
445 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
446 # error	"You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
447 #endif
448 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
449 extern void bio_flush_dcache_pages(struct bio *bi);
450 #else
451 static inline void bio_flush_dcache_pages(struct bio *bi)
452 {
453 }
454 #endif
455 
456 extern void bio_copy_data(struct bio *dst, struct bio *src);
457 extern int bio_alloc_pages(struct bio *bio, gfp_t gfp);
458 
459 extern struct bio *bio_copy_user_iov(struct request_queue *,
460 				     struct rq_map_data *,
461 				     const struct iov_iter *,
462 				     gfp_t);
463 extern int bio_uncopy_user(struct bio *);
464 void zero_fill_bio(struct bio *bio);
465 extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *);
466 extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int);
467 extern unsigned int bvec_nr_vecs(unsigned short idx);
468 
469 #ifdef CONFIG_BLK_CGROUP
470 int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css);
471 int bio_associate_current(struct bio *bio);
472 void bio_disassociate_task(struct bio *bio);
473 void bio_clone_blkcg_association(struct bio *dst, struct bio *src);
474 #else	/* CONFIG_BLK_CGROUP */
475 static inline int bio_associate_blkcg(struct bio *bio,
476 			struct cgroup_subsys_state *blkcg_css) { return 0; }
477 static inline int bio_associate_current(struct bio *bio) { return -ENOENT; }
478 static inline void bio_disassociate_task(struct bio *bio) { }
479 static inline void bio_clone_blkcg_association(struct bio *dst,
480 			struct bio *src) { }
481 #endif	/* CONFIG_BLK_CGROUP */
482 
483 #ifdef CONFIG_HIGHMEM
484 /*
485  * remember never ever reenable interrupts between a bvec_kmap_irq and
486  * bvec_kunmap_irq!
487  */
488 static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
489 {
490 	unsigned long addr;
491 
492 	/*
493 	 * might not be a highmem page, but the preempt/irq count
494 	 * balancing is a lot nicer this way
495 	 */
496 	local_irq_save(*flags);
497 	addr = (unsigned long) kmap_atomic(bvec->bv_page);
498 
499 	BUG_ON(addr & ~PAGE_MASK);
500 
501 	return (char *) addr + bvec->bv_offset;
502 }
503 
504 static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
505 {
506 	unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
507 
508 	kunmap_atomic((void *) ptr);
509 	local_irq_restore(*flags);
510 }
511 
512 #else
513 static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
514 {
515 	return page_address(bvec->bv_page) + bvec->bv_offset;
516 }
517 
518 static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
519 {
520 	*flags = 0;
521 }
522 #endif
523 
524 static inline char *__bio_kmap_irq(struct bio *bio, struct bvec_iter iter,
525 				   unsigned long *flags)
526 {
527 	return bvec_kmap_irq(&bio_iter_iovec(bio, iter), flags);
528 }
529 #define __bio_kunmap_irq(buf, flags)	bvec_kunmap_irq(buf, flags)
530 
531 #define bio_kmap_irq(bio, flags) \
532 	__bio_kmap_irq((bio), (bio)->bi_iter, (flags))
533 #define bio_kunmap_irq(buf,flags)	__bio_kunmap_irq(buf, flags)
534 
535 /*
536  * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
537  *
538  * A bio_list anchors a singly-linked list of bios chained through the bi_next
539  * member of the bio.  The bio_list also caches the last list member to allow
540  * fast access to the tail.
541  */
542 struct bio_list {
543 	struct bio *head;
544 	struct bio *tail;
545 };
546 
547 static inline int bio_list_empty(const struct bio_list *bl)
548 {
549 	return bl->head == NULL;
550 }
551 
552 static inline void bio_list_init(struct bio_list *bl)
553 {
554 	bl->head = bl->tail = NULL;
555 }
556 
557 #define BIO_EMPTY_LIST	{ NULL, NULL }
558 
559 #define bio_list_for_each(bio, bl) \
560 	for (bio = (bl)->head; bio; bio = bio->bi_next)
561 
562 static inline unsigned bio_list_size(const struct bio_list *bl)
563 {
564 	unsigned sz = 0;
565 	struct bio *bio;
566 
567 	bio_list_for_each(bio, bl)
568 		sz++;
569 
570 	return sz;
571 }
572 
573 static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
574 {
575 	bio->bi_next = NULL;
576 
577 	if (bl->tail)
578 		bl->tail->bi_next = bio;
579 	else
580 		bl->head = bio;
581 
582 	bl->tail = bio;
583 }
584 
585 static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
586 {
587 	bio->bi_next = bl->head;
588 
589 	bl->head = bio;
590 
591 	if (!bl->tail)
592 		bl->tail = bio;
593 }
594 
595 static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
596 {
597 	if (!bl2->head)
598 		return;
599 
600 	if (bl->tail)
601 		bl->tail->bi_next = bl2->head;
602 	else
603 		bl->head = bl2->head;
604 
605 	bl->tail = bl2->tail;
606 }
607 
608 static inline void bio_list_merge_head(struct bio_list *bl,
609 				       struct bio_list *bl2)
610 {
611 	if (!bl2->head)
612 		return;
613 
614 	if (bl->head)
615 		bl2->tail->bi_next = bl->head;
616 	else
617 		bl->tail = bl2->tail;
618 
619 	bl->head = bl2->head;
620 }
621 
622 static inline struct bio *bio_list_peek(struct bio_list *bl)
623 {
624 	return bl->head;
625 }
626 
627 static inline struct bio *bio_list_pop(struct bio_list *bl)
628 {
629 	struct bio *bio = bl->head;
630 
631 	if (bio) {
632 		bl->head = bl->head->bi_next;
633 		if (!bl->head)
634 			bl->tail = NULL;
635 
636 		bio->bi_next = NULL;
637 	}
638 
639 	return bio;
640 }
641 
642 static inline struct bio *bio_list_get(struct bio_list *bl)
643 {
644 	struct bio *bio = bl->head;
645 
646 	bl->head = bl->tail = NULL;
647 
648 	return bio;
649 }
650 
651 /*
652  * Increment chain count for the bio. Make sure the CHAIN flag update
653  * is visible before the raised count.
654  */
655 static inline void bio_inc_remaining(struct bio *bio)
656 {
657 	bio_set_flag(bio, BIO_CHAIN);
658 	smp_mb__before_atomic();
659 	atomic_inc(&bio->__bi_remaining);
660 }
661 
662 /*
663  * bio_set is used to allow other portions of the IO system to
664  * allocate their own private memory pools for bio and iovec structures.
665  * These memory pools in turn all allocate from the bio_slab
666  * and the bvec_slabs[].
667  */
668 #define BIO_POOL_SIZE 2
669 
670 struct bio_set {
671 	struct kmem_cache *bio_slab;
672 	unsigned int front_pad;
673 
674 	mempool_t *bio_pool;
675 	mempool_t *bvec_pool;
676 #if defined(CONFIG_BLK_DEV_INTEGRITY)
677 	mempool_t *bio_integrity_pool;
678 	mempool_t *bvec_integrity_pool;
679 #endif
680 
681 	/*
682 	 * Deadlock avoidance for stacking block drivers: see comments in
683 	 * bio_alloc_bioset() for details
684 	 */
685 	spinlock_t		rescue_lock;
686 	struct bio_list		rescue_list;
687 	struct work_struct	rescue_work;
688 	struct workqueue_struct	*rescue_workqueue;
689 };
690 
691 struct biovec_slab {
692 	int nr_vecs;
693 	char *name;
694 	struct kmem_cache *slab;
695 };
696 
697 /*
698  * a small number of entries is fine, not going to be performance critical.
699  * basically we just need to survive
700  */
701 #define BIO_SPLIT_ENTRIES 2
702 
703 #if defined(CONFIG_BLK_DEV_INTEGRITY)
704 
705 #define bip_for_each_vec(bvl, bip, iter)				\
706 	for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
707 
708 #define bio_for_each_integrity_vec(_bvl, _bio, _iter)			\
709 	for_each_bio(_bio)						\
710 		bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
711 
712 extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
713 extern void bio_integrity_free(struct bio *);
714 extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
715 extern bool bio_integrity_enabled(struct bio *bio);
716 extern int bio_integrity_prep(struct bio *);
717 extern void bio_integrity_endio(struct bio *);
718 extern void bio_integrity_advance(struct bio *, unsigned int);
719 extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
720 extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t);
721 extern int bioset_integrity_create(struct bio_set *, int);
722 extern void bioset_integrity_free(struct bio_set *);
723 extern void bio_integrity_init(void);
724 
725 #else /* CONFIG_BLK_DEV_INTEGRITY */
726 
727 static inline void *bio_integrity(struct bio *bio)
728 {
729 	return NULL;
730 }
731 
732 static inline bool bio_integrity_enabled(struct bio *bio)
733 {
734 	return false;
735 }
736 
737 static inline int bioset_integrity_create(struct bio_set *bs, int pool_size)
738 {
739 	return 0;
740 }
741 
742 static inline void bioset_integrity_free (struct bio_set *bs)
743 {
744 	return;
745 }
746 
747 static inline int bio_integrity_prep(struct bio *bio)
748 {
749 	return 0;
750 }
751 
752 static inline void bio_integrity_free(struct bio *bio)
753 {
754 	return;
755 }
756 
757 static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
758 				      gfp_t gfp_mask)
759 {
760 	return 0;
761 }
762 
763 static inline void bio_integrity_advance(struct bio *bio,
764 					 unsigned int bytes_done)
765 {
766 	return;
767 }
768 
769 static inline void bio_integrity_trim(struct bio *bio, unsigned int offset,
770 				      unsigned int sectors)
771 {
772 	return;
773 }
774 
775 static inline void bio_integrity_init(void)
776 {
777 	return;
778 }
779 
780 static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
781 {
782 	return false;
783 }
784 
785 static inline void *bio_integrity_alloc(struct bio * bio, gfp_t gfp,
786 								unsigned int nr)
787 {
788 	return ERR_PTR(-EINVAL);
789 }
790 
791 static inline int bio_integrity_add_page(struct bio *bio, struct page *page,
792 					unsigned int len, unsigned int offset)
793 {
794 	return 0;
795 }
796 
797 #endif /* CONFIG_BLK_DEV_INTEGRITY */
798 
799 #endif /* CONFIG_BLOCK */
800 #endif /* __LINUX_BIO_H */
801