bio.h 19.8 KB
Newer Older
1
/* SPDX-License-Identifier: GPL-2.0 */
L
Linus Torvalds 已提交
2 3 4 5 6 7 8 9
/*
 * Copyright (C) 2001 Jens Axboe <axboe@suse.de>
 */
#ifndef __LINUX_BIO_H
#define __LINUX_BIO_H

#include <linux/highmem.h>
#include <linux/mempool.h>
10
#include <linux/ioprio.h>
11 12 13
/* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */
#include <linux/blk_types.h>

L
Linus Torvalds 已提交
14 15 16 17 18 19 20 21
#define BIO_DEBUG

#ifdef BIO_DEBUG
#define BIO_BUG_ON	BUG_ON
#else
#define BIO_BUG_ON
#endif

22
#define BIO_MAX_PAGES		256
L
Linus Torvalds 已提交
23

24 25
#define bio_prio(bio)			(bio)->bi_ioprio
#define bio_set_prio(bio, prio)		((bio)->bi_ioprio = prio)
26

K
Kent Overstreet 已提交
27 28 29 30 31 32 33 34 35 36 37 38 39
#define bio_iter_iovec(bio, iter)				\
	bvec_iter_bvec((bio)->bi_io_vec, (iter))

#define bio_iter_page(bio, iter)				\
	bvec_iter_page((bio)->bi_io_vec, (iter))
#define bio_iter_len(bio, iter)					\
	bvec_iter_len((bio)->bi_io_vec, (iter))
#define bio_iter_offset(bio, iter)				\
	bvec_iter_offset((bio)->bi_io_vec, (iter))

#define bio_page(bio)		bio_iter_page((bio), (bio)->bi_iter)
#define bio_offset(bio)		bio_iter_offset((bio), (bio)->bi_iter)
#define bio_iovec(bio)		bio_iter_iovec((bio), (bio)->bi_iter)
40

41 42
#define bio_multiple_segments(bio)				\
	((bio)->bi_iter.bi_size != bio_iovec(bio).bv_len)
43 44 45 46 47 48

#define bvec_iter_sectors(iter)	((iter).bi_size >> 9)
#define bvec_iter_end_sector(iter) ((iter).bi_sector + bvec_iter_sectors((iter)))

#define bio_sectors(bio)	bvec_iter_sectors((bio)->bi_iter)
#define bio_end_sector(bio)	bvec_iter_end_sector((bio)->bi_iter)
49

50 51 52 53 54 55
/*
 * Return the data direction, READ or WRITE.
 */
#define bio_data_dir(bio) \
	(op_is_write(bio_op(bio)) ? WRITE : READ)

56 57 58 59 60 61 62
/*
 * Check whether this bio carries any data or not. A NULL bio is allowed.
 */
static inline bool bio_has_data(struct bio *bio)
{
	if (bio &&
	    bio->bi_iter.bi_size &&
A
Adrian Hunter 已提交
63
	    bio_op(bio) != REQ_OP_DISCARD &&
64 65
	    bio_op(bio) != REQ_OP_SECURE_ERASE &&
	    bio_op(bio) != REQ_OP_WRITE_ZEROES)
66 67 68 69 70
		return true;

	return false;
}

71
static inline bool bio_no_advance_iter(const struct bio *bio)
72
{
A
Adrian Hunter 已提交
73 74
	return bio_op(bio) == REQ_OP_DISCARD ||
	       bio_op(bio) == REQ_OP_SECURE_ERASE ||
75 76
	       bio_op(bio) == REQ_OP_WRITE_SAME ||
	       bio_op(bio) == REQ_OP_WRITE_ZEROES;
77 78
}

79 80
static inline bool bio_mergeable(struct bio *bio)
{
J
Jens Axboe 已提交
81
	if (bio->bi_opf & REQ_NOMERGE_FLAGS)
82 83 84 85 86
		return false;

	return true;
}

87
static inline unsigned int bio_cur_bytes(struct bio *bio)
88
{
89
	if (bio_has_data(bio))
90
		return bio_iovec(bio).bv_len;
D
David Woodhouse 已提交
91
	else /* dataless requests such as discard */
92
		return bio->bi_iter.bi_size;
93 94 95 96
}

static inline void *bio_data(struct bio *bio)
{
97
	if (bio_has_data(bio))
98 99 100 101
		return page_address(bio_page(bio)) + bio_offset(bio);

	return NULL;
}
L
Linus Torvalds 已提交
102

M
Ming Lei 已提交
103 104 105 106 107 108 109 110 111
/**
 * bio_full - check if the bio is full
 * @bio:	bio to check
 * @len:	length of one segment to be added
 *
 * Return true if @bio is full and one segment with @len bytes can't be
 * added to the bio, otherwise return false
 */
static inline bool bio_full(struct bio *bio, unsigned len)
112
{
M
Ming Lei 已提交
113 114 115 116 117 118 119
	if (bio->bi_vcnt >= bio->bi_max_vecs)
		return true;

	if (bio->bi_iter.bi_size > UINT_MAX - len)
		return true;

	return false;
120 121
}

122 123 124 125 126 127 128 129 130
static inline bool bio_next_segment(const struct bio *bio,
				    struct bvec_iter_all *iter)
{
	if (iter->idx >= bio->bi_vcnt)
		return false;

	bvec_advance(&bio->bi_io_vec[iter->idx], iter);
	return true;
}
131

132 133 134 135
/*
 * drivers should _never_ use the all version - the bio may have been split
 * before it got to the driver and the driver won't own all of it
 */
136 137
#define bio_for_each_segment_all(bvl, bio, iter) \
	for (bvl = bvec_init_iter_all(&iter); bio_next_segment((bio), &iter); )
138

139 140
static inline void bio_advance_iter(const struct bio *bio,
				    struct bvec_iter *iter, unsigned int bytes)
K
Kent Overstreet 已提交
141 142 143
{
	iter->bi_sector += bytes >> 9;

M
Ming Lei 已提交
144
	if (bio_no_advance_iter(bio))
K
Kent Overstreet 已提交
145
		iter->bi_size -= bytes;
M
Ming Lei 已提交
146
	else
K
Kent Overstreet 已提交
147
		bvec_iter_advance(bio->bi_io_vec, iter, bytes);
148
		/* TODO: It is reasonable to complete bio with error here. */
D
Dmitry Monakhov 已提交
149 150
}

151 152
#define __bio_for_each_segment(bvl, bio, iter, start)			\
	for (iter = (start);						\
K
Kent Overstreet 已提交
153 154 155
	     (iter).bi_size &&						\
		((bvl = bio_iter_iovec((bio), (iter))), 1);		\
	     bio_advance_iter((bio), &(iter), (bvl).bv_len))
156 157 158 159

#define bio_for_each_segment(bvl, bio, iter)				\
	__bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter)

160 161 162 163 164 165 166 167 168 169
#define __bio_for_each_bvec(bvl, bio, iter, start)		\
	for (iter = (start);						\
	     (iter).bi_size &&						\
		((bvl = mp_bvec_iter_bvec((bio)->bi_io_vec, (iter))), 1); \
	     bio_advance_iter((bio), &(iter), (bvl).bv_len))

/* iterate over multi-page bvec */
#define bio_for_each_bvec(bvl, bio, iter)			\
	__bio_for_each_bvec(bvl, bio, iter, (bio)->bi_iter)

170 171 172 173 174 175 176 177
/*
 * Iterate over all multi-page bvecs. Drivers shouldn't use this version for the
 * same reasons as bio_for_each_segment_all().
 */
#define bio_for_each_bvec_all(bvl, bio, i)		\
	for (i = 0, bvl = bio_first_bvec_all(bio);	\
	     i < (bio)->bi_vcnt; i++, bvl++)		\

K
Kent Overstreet 已提交
178
#define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)
L
Linus Torvalds 已提交
179

180
static inline unsigned bio_segments(struct bio *bio)
181 182 183 184 185
{
	unsigned segs = 0;
	struct bio_vec bv;
	struct bvec_iter iter;

186
	/*
187 188
	 * We special case discard/write same/write zeroes, because they
	 * interpret bi_size differently:
189 190
	 */

191 192 193 194
	switch (bio_op(bio)) {
	case REQ_OP_DISCARD:
	case REQ_OP_SECURE_ERASE:
	case REQ_OP_WRITE_ZEROES:
195 196
		return 0;
	case REQ_OP_WRITE_SAME:
197
		return 1;
198 199 200
	default:
		break;
	}
201

202
	bio_for_each_segment(bv, bio, iter)
203 204 205 206 207
		segs++;

	return segs;
}

L
Linus Torvalds 已提交
208 209 210 211 212 213 214 215 216 217 218 219 220 221
/*
 * get a reference to a bio, so it won't disappear. the intended use is
 * something like:
 *
 * bio_get(bio);
 * submit_bio(rw, bio);
 * if (bio->bi_flags ...)
 *	do_something
 * bio_put(bio);
 *
 * without the bio_get(), it could potentially complete I/O before submit_bio
 * returns. and then bio would be freed memory when if (bio->bi_flags ...)
 * runs
 */
222 223 224 225 226 227 228 229 230 231 232
static inline void bio_get(struct bio *bio)
{
	bio->bi_flags |= (1 << BIO_REFFED);
	smp_mb__before_atomic();
	atomic_inc(&bio->__bi_cnt);
}

static inline void bio_cnt_set(struct bio *bio, unsigned int count)
{
	if (count != 1) {
		bio->bi_flags |= (1 << BIO_REFFED);
233
		smp_mb();
234 235 236
	}
	atomic_set(&bio->__bi_cnt, count);
}
L
Linus Torvalds 已提交
237

238 239
static inline bool bio_flagged(struct bio *bio, unsigned int bit)
{
240
	return (bio->bi_flags & (1U << bit)) != 0;
241 242 243 244
}

static inline void bio_set_flag(struct bio *bio, unsigned int bit)
{
245
	bio->bi_flags |= (1U << bit);
246 247 248 249
}

static inline void bio_clear_flag(struct bio *bio, unsigned int bit)
{
250
	bio->bi_flags &= ~(1U << bit);
251 252
}

253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284
static inline void bio_get_first_bvec(struct bio *bio, struct bio_vec *bv)
{
	*bv = bio_iovec(bio);
}

static inline void bio_get_last_bvec(struct bio *bio, struct bio_vec *bv)
{
	struct bvec_iter iter = bio->bi_iter;
	int idx;

	if (unlikely(!bio_multiple_segments(bio))) {
		*bv = bio_iovec(bio);
		return;
	}

	bio_advance_iter(bio, &iter, iter.bi_size);

	if (!iter.bi_bvec_done)
		idx = iter.bi_idx - 1;
	else	/* in the middle of bvec */
		idx = iter.bi_idx;

	*bv = bio->bi_io_vec[idx];

	/*
	 * iter.bi_bvec_done records actual length of the last bvec
	 * if this bio ends in the middle of one io vector
	 */
	if (iter.bi_bvec_done)
		bv->bv_len = iter.bi_bvec_done;
}

285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301
static inline struct bio_vec *bio_first_bvec_all(struct bio *bio)
{
	WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
	return bio->bi_io_vec;
}

static inline struct page *bio_first_page_all(struct bio *bio)
{
	return bio_first_bvec_all(bio)->bv_page;
}

static inline struct bio_vec *bio_last_bvec_all(struct bio *bio)
{
	WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
	return &bio->bi_io_vec[bio->bi_vcnt - 1];
}

302 303 304 305 306 307 308 309
enum bip_flags {
	BIP_BLOCK_INTEGRITY	= 1 << 0, /* block layer owns integrity data */
	BIP_MAPPED_INTEGRITY	= 1 << 1, /* ref tag has been remapped */
	BIP_CTRL_NOCHECK	= 1 << 2, /* disable HBA integrity checking */
	BIP_DISK_NOCHECK	= 1 << 3, /* disable disk integrity checking */
	BIP_IP_CHECKSUM		= 1 << 4, /* IP checksum */
};

310 311 312 313 314 315
/*
 * bio integrity payload
 */
struct bio_integrity_payload {
	struct bio		*bip_bio;	/* parent bio */

316
	struct bvec_iter	bip_iter;
317

318
	unsigned short		bip_slab;	/* slab the bip came from */
319
	unsigned short		bip_vcnt;	/* # of integrity bio_vecs */
320
	unsigned short		bip_max_vcnt;	/* integrity bio_vec slots */
321
	unsigned short		bip_flags;	/* control flags */
322

M
Ming Lei 已提交
323 324
	struct bvec_iter	bio_iter;	/* for rewinding parent bio */

325
	struct work_struct	bip_work;	/* I/O completion */
326 327

	struct bio_vec		*bip_vec;
328
	struct bio_vec		bip_inline_vecs[];/* embedded bvec array */
329
};
330

331 332 333 334
#if defined(CONFIG_BLK_DEV_INTEGRITY)

static inline struct bio_integrity_payload *bio_integrity(struct bio *bio)
{
J
Jens Axboe 已提交
335
	if (bio->bi_opf & REQ_INTEGRITY)
336 337 338 339 340
		return bio->bi_integrity;

	return NULL;
}

341 342 343 344 345 346 347 348 349
static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
{
	struct bio_integrity_payload *bip = bio_integrity(bio);

	if (bip)
		return bip->bip_flags & flag;

	return false;
}
350

351 352 353 354 355 356 357 358 359 360 361
static inline sector_t bip_get_seed(struct bio_integrity_payload *bip)
{
	return bip->bip_iter.bi_sector;
}

static inline void bip_set_seed(struct bio_integrity_payload *bip,
				sector_t seed)
{
	bip->bip_iter.bi_sector = seed;
}

362
#endif /* CONFIG_BLK_DEV_INTEGRITY */
L
Linus Torvalds 已提交
363

364
extern void bio_trim(struct bio *bio, int offset, int size);
K
Kent Overstreet 已提交
365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386
extern struct bio *bio_split(struct bio *bio, int sectors,
			     gfp_t gfp, struct bio_set *bs);

/**
 * bio_next_split - get next @sectors from a bio, splitting if necessary
 * @bio:	bio to split
 * @sectors:	number of sectors to split from the front of @bio
 * @gfp:	gfp mask
 * @bs:		bio set to allocate from
 *
 * Returns a bio representing the next @sectors of @bio - if the bio is smaller
 * than @sectors, returns the original bio unchanged.
 */
static inline struct bio *bio_next_split(struct bio *bio, int sectors,
					 gfp_t gfp, struct bio_set *bs)
{
	if (sectors >= bio_sectors(bio))
		return bio;

	return bio_split(bio, sectors, gfp, bs);
}

387 388
enum {
	BIOSET_NEED_BVECS = BIT(0),
389
	BIOSET_NEED_RESCUER = BIT(1),
390
};
K
Kent Overstreet 已提交
391 392
extern int bioset_init(struct bio_set *, unsigned int, unsigned int, int flags);
extern void bioset_exit(struct bio_set *);
393
extern int biovec_init_pool(mempool_t *pool, int pool_entries);
394
extern int bioset_init_from_src(struct bio_set *bs, struct bio_set *src);
L
Linus Torvalds 已提交
395

396
extern struct bio *bio_alloc_bioset(gfp_t, unsigned int, struct bio_set *);
L
Linus Torvalds 已提交
397 398
extern void bio_put(struct bio *);

K
Kent Overstreet 已提交
399 400
extern void __bio_clone_fast(struct bio *, struct bio *);
extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *);
401

402
extern struct bio_set fs_bio_set;
403 404 405

static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
{
406
	return bio_alloc_bioset(gfp_mask, nr_iovecs, &fs_bio_set);
407 408 409 410 411 412 413
}

static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
{
	return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
}

414 415
extern blk_qc_t submit_bio(struct bio *);

416 417 418 419
extern void bio_endio(struct bio *);

static inline void bio_io_error(struct bio *bio)
{
420
	bio->bi_status = BLK_STS_IOERR;
421 422 423
	bio_endio(bio);
}

424 425
static inline void bio_wouldblock_error(struct bio *bio)
{
426
	bio_set_flag(bio, BIO_QUIET);
427
	bio->bi_status = BLK_STS_AGAIN;
428 429 430
	bio_endio(bio);
}

L
Linus Torvalds 已提交
431 432
struct request_queue;

433
extern int submit_bio_wait(struct bio *bio);
K
Kent Overstreet 已提交
434 435
extern void bio_advance(struct bio *, unsigned);

436 437
extern void bio_init(struct bio *bio, struct bio_vec *table,
		     unsigned short max_vecs);
438
extern void bio_uninit(struct bio *);
K
Kent Overstreet 已提交
439
extern void bio_reset(struct bio *);
K
Kent Overstreet 已提交
440
void bio_chain(struct bio *, struct bio *);
L
Linus Torvalds 已提交
441 442

extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
443 444
extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
			   unsigned int, unsigned int);
445
bool __bio_try_merge_page(struct bio *bio, struct page *page,
446
		unsigned int len, unsigned int off, bool *same_page);
447 448
void __bio_add_page(struct bio *bio, struct page *page,
		unsigned int len, unsigned int off);
449
int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter);
450
void bio_release_pages(struct bio *bio, bool mark_dirty);
L
Linus Torvalds 已提交
451 452
extern void bio_set_pages_dirty(struct bio *bio);
extern void bio_check_pages_dirty(struct bio *bio);
453

454 455
extern void bio_copy_data_iter(struct bio *dst, struct bvec_iter *dst_iter,
			       struct bio *src, struct bvec_iter *src_iter);
K
Kent Overstreet 已提交
456
extern void bio_copy_data(struct bio *dst, struct bio *src);
457
extern void bio_list_copy_data(struct bio *dst, struct bio *src);
458
extern void bio_free_pages(struct bio *bio);
459
void zero_fill_bio_iter(struct bio *bio, struct bvec_iter iter);
460
void bio_truncate(struct bio *bio, unsigned new_size);
461
void guard_bio_eod(struct bio *bio);
462 463 464 465 466 467

static inline void zero_fill_bio(struct bio *bio)
{
	zero_fill_bio_iter(bio, bio->bi_iter);
}

468 469
extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *);
extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int);
470
extern unsigned int bvec_nr_vecs(unsigned short idx);
471
extern const char *bio_devname(struct bio *bio, char *buffer);
472

473 474
#define bio_set_dev(bio, bdev) 			\
do {						\
S
Shaohua Li 已提交
475 476
	if ((bio)->bi_disk != (bdev)->bd_disk)	\
		bio_clear_flag(bio, BIO_THROTTLED);\
477 478
	(bio)->bi_disk = (bdev)->bd_disk;	\
	(bio)->bi_partno = (bdev)->bd_partno;	\
479
	bio_associate_blkg(bio);		\
480 481 482 483 484 485
} while (0)

#define bio_copy_dev(dst, src)			\
do {						\
	(dst)->bi_disk = (src)->bi_disk;	\
	(dst)->bi_partno = (src)->bi_partno;	\
486
	bio_clone_blkg_association(dst, src);	\
487 488 489 490 491
} while (0)

#define bio_dev(bio) \
	disk_devt((bio)->bi_disk)

492
#ifdef CONFIG_BLK_CGROUP
493
void bio_associate_blkg(struct bio *bio);
494 495
void bio_associate_blkg_from_css(struct bio *bio,
				 struct cgroup_subsys_state *css);
496
void bio_clone_blkg_association(struct bio *dst, struct bio *src);
497
#else	/* CONFIG_BLK_CGROUP */
498
static inline void bio_associate_blkg(struct bio *bio) { }
499 500 501
static inline void bio_associate_blkg_from_css(struct bio *bio,
					       struct cgroup_subsys_state *css)
{ }
502 503
static inline void bio_clone_blkg_association(struct bio *dst,
					      struct bio *src) { }
504 505
#endif	/* CONFIG_BLK_CGROUP */

L
Linus Torvalds 已提交
506 507
#ifdef CONFIG_HIGHMEM
/*
508 509
 * remember never ever reenable interrupts between a bvec_kmap_irq and
 * bvec_kunmap_irq!
L
Linus Torvalds 已提交
510
 */
511
static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
L
Linus Torvalds 已提交
512 513 514 515 516 517 518 519
{
	unsigned long addr;

	/*
	 * might not be a highmem page, but the preempt/irq count
	 * balancing is a lot nicer this way
	 */
	local_irq_save(*flags);
520
	addr = (unsigned long) kmap_atomic(bvec->bv_page);
L
Linus Torvalds 已提交
521 522 523 524 525 526

	BUG_ON(addr & ~PAGE_MASK);

	return (char *) addr + bvec->bv_offset;
}

527
static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
L
Linus Torvalds 已提交
528 529 530
{
	unsigned long ptr = (unsigned long) buffer & PAGE_MASK;

531
	kunmap_atomic((void *) ptr);
L
Linus Torvalds 已提交
532 533 534 535
	local_irq_restore(*flags);
}

#else
536 537 538 539 540 541 542 543 544
static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
{
	return page_address(bvec->bv_page) + bvec->bv_offset;
}

static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
{
	*flags = 0;
}
L
Linus Torvalds 已提交
545 546
#endif

547
/*
548
 * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568
 *
 * A bio_list anchors a singly-linked list of bios chained through the bi_next
 * member of the bio.  The bio_list also caches the last list member to allow
 * fast access to the tail.
 */
struct bio_list {
	struct bio *head;
	struct bio *tail;
};

static inline int bio_list_empty(const struct bio_list *bl)
{
	return bl->head == NULL;
}

static inline void bio_list_init(struct bio_list *bl)
{
	bl->head = bl->tail = NULL;
}

569 570
#define BIO_EMPTY_LIST	{ NULL, NULL }

571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633
#define bio_list_for_each(bio, bl) \
	for (bio = (bl)->head; bio; bio = bio->bi_next)

static inline unsigned bio_list_size(const struct bio_list *bl)
{
	unsigned sz = 0;
	struct bio *bio;

	bio_list_for_each(bio, bl)
		sz++;

	return sz;
}

static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
{
	bio->bi_next = NULL;

	if (bl->tail)
		bl->tail->bi_next = bio;
	else
		bl->head = bio;

	bl->tail = bio;
}

static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
{
	bio->bi_next = bl->head;

	bl->head = bio;

	if (!bl->tail)
		bl->tail = bio;
}

static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
{
	if (!bl2->head)
		return;

	if (bl->tail)
		bl->tail->bi_next = bl2->head;
	else
		bl->head = bl2->head;

	bl->tail = bl2->tail;
}

static inline void bio_list_merge_head(struct bio_list *bl,
				       struct bio_list *bl2)
{
	if (!bl2->head)
		return;

	if (bl->head)
		bl2->tail->bi_next = bl->head;
	else
		bl->tail = bl2->tail;

	bl->head = bl2->head;
}

G
Geert Uytterhoeven 已提交
634 635 636 637 638
static inline struct bio *bio_list_peek(struct bio_list *bl)
{
	return bl->head;
}

639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662
static inline struct bio *bio_list_pop(struct bio_list *bl)
{
	struct bio *bio = bl->head;

	if (bio) {
		bl->head = bl->head->bi_next;
		if (!bl->head)
			bl->tail = NULL;

		bio->bi_next = NULL;
	}

	return bio;
}

static inline struct bio *bio_list_get(struct bio_list *bl)
{
	struct bio *bio = bl->head;

	bl->head = bl->tail = NULL;

	return bio;
}

663 664 665 666 667 668 669 670 671 672 673
/*
 * Increment chain count for the bio. Make sure the CHAIN flag update
 * is visible before the raised count.
 */
static inline void bio_inc_remaining(struct bio *bio)
{
	bio_set_flag(bio, BIO_CHAIN);
	smp_mb__before_atomic();
	atomic_inc(&bio->__bi_remaining);
}

K
Kent Overstreet 已提交
674 675 676 677 678 679 680 681 682 683 684 685
/*
 * bio_set is used to allow other portions of the IO system to
 * allocate their own private memory pools for bio and iovec structures.
 * These memory pools in turn all allocate from the bio_slab
 * and the bvec_slabs[].
 */
#define BIO_POOL_SIZE 2

struct bio_set {
	struct kmem_cache *bio_slab;
	unsigned int front_pad;

686 687
	mempool_t bio_pool;
	mempool_t bvec_pool;
K
Kent Overstreet 已提交
688
#if defined(CONFIG_BLK_DEV_INTEGRITY)
689 690
	mempool_t bio_integrity_pool;
	mempool_t bvec_integrity_pool;
K
Kent Overstreet 已提交
691
#endif
692 693 694 695 696 697 698 699 700

	/*
	 * Deadlock avoidance for stacking block drivers: see comments in
	 * bio_alloc_bioset() for details
	 */
	spinlock_t		rescue_lock;
	struct bio_list		rescue_list;
	struct work_struct	rescue_work;
	struct workqueue_struct	*rescue_workqueue;
K
Kent Overstreet 已提交
701 702 703 704 705 706 707 708
};

struct biovec_slab {
	int nr_vecs;
	char *name;
	struct kmem_cache *slab;
};

709 710 711 712 713
static inline bool bioset_initialized(struct bio_set *bs)
{
	return bs->bio_slab != NULL;
}

714 715
#if defined(CONFIG_BLK_DEV_INTEGRITY)

716 717
#define bip_for_each_vec(bvl, bip, iter)				\
	for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
718

719 720 721 722
#define bio_for_each_integrity_vec(_bvl, _bio, _iter)			\
	for_each_bio(_bio)						\
		bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)

723 724
extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
725
extern bool bio_integrity_prep(struct bio *);
726
extern void bio_integrity_advance(struct bio *, unsigned int);
727
extern void bio_integrity_trim(struct bio *);
728
extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t);
729 730 731
extern int bioset_integrity_create(struct bio_set *, int);
extern void bioset_integrity_free(struct bio_set *);
extern void bio_integrity_init(void);
732 733 734

#else /* CONFIG_BLK_DEV_INTEGRITY */

735
static inline void *bio_integrity(struct bio *bio)
736
{
737
	return NULL;
738 739 740 741 742 743 744 745 746 747 748 749
}

static inline int bioset_integrity_create(struct bio_set *bs, int pool_size)
{
	return 0;
}

static inline void bioset_integrity_free (struct bio_set *bs)
{
	return;
}

750
static inline bool bio_integrity_prep(struct bio *bio)
751
{
752
	return true;
753 754
}

755
static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
756
				      gfp_t gfp_mask)
757 758 759
{
	return 0;
}
760 761 762 763 764 765 766

static inline void bio_integrity_advance(struct bio *bio,
					 unsigned int bytes_done)
{
	return;
}

767
static inline void bio_integrity_trim(struct bio *bio)
768 769 770 771 772 773 774 775
{
	return;
}

static inline void bio_integrity_init(void)
{
	return;
}
776

777 778 779 780 781
static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
{
	return false;
}

782 783 784 785 786 787 788 789 790 791 792 793
static inline void *bio_integrity_alloc(struct bio * bio, gfp_t gfp,
								unsigned int nr)
{
	return ERR_PTR(-EINVAL);
}

static inline int bio_integrity_add_page(struct bio *bio, struct page *page,
					unsigned int len, unsigned int offset)
{
	return 0;
}

794 795
#endif /* CONFIG_BLK_DEV_INTEGRITY */

J
Jens Axboe 已提交
796 797 798 799 800 801 802 803 804 805 806 807 808 809
/*
 * Mark a bio as polled. Note that for async polled IO, the caller must
 * expect -EWOULDBLOCK if we cannot allocate a request (or other resources).
 * We cannot block waiting for requests on polled IO, as those completions
 * must be found by the caller. This is different than IRQ driven IO, where
 * it's safe to wait for IO to complete.
 */
static inline void bio_set_polled(struct bio *bio, struct kiocb *kiocb)
{
	bio->bi_opf |= REQ_HIPRI;
	if (!is_sync_kiocb(kiocb))
		bio->bi_opf |= REQ_NOWAIT;
}

L
Linus Torvalds 已提交
810
#endif /* __LINUX_BIO_H */