bio.h 20.4 KB
Newer Older
L
Linus Torvalds 已提交
1 2 3 4 5 6 7 8 9 10 11
/*
 * 2.5 block I/O model
 *
 * Copyright (C) 2001 Jens Axboe <axboe@suse.de>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12
 *
L
Linus Torvalds 已提交
13 14 15 16 17 18 19 20 21 22 23 24
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public Licens
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-
 */
#ifndef __LINUX_BIO_H
#define __LINUX_BIO_H

#include <linux/highmem.h>
#include <linux/mempool.h>
25
#include <linux/ioprio.h>
26
#include <linux/bug.h>
L
Linus Torvalds 已提交
27

28 29
#ifdef CONFIG_BLOCK

L
Linus Torvalds 已提交
30 31
#include <asm/io.h>

32 33 34
/* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */
#include <linux/blk_types.h>

L
Linus Torvalds 已提交
35 36 37 38 39 40 41 42
#define BIO_DEBUG

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

43
#define BIO_MAX_PAGES		256
L
Linus Torvalds 已提交
44 45 46
#define BIO_MAX_SIZE		(BIO_MAX_PAGES << PAGE_CACHE_SHIFT)
#define BIO_MAX_SECTORS		(BIO_MAX_SIZE >> 9)

47 48 49 50 51 52 53 54 55 56 57 58 59
/*
 * upper 16 bits of bi_rw define the io priority of this bio
 */
#define BIO_PRIO_SHIFT	(8 * sizeof(unsigned long) - IOPRIO_BITS)
#define bio_prio(bio)	((bio)->bi_rw >> BIO_PRIO_SHIFT)
#define bio_prio_valid(bio)	ioprio_valid(bio_prio(bio))

#define bio_set_prio(bio, prio)		do {			\
	WARN_ON(prio >= (1 << IOPRIO_BITS));			\
	(bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1);		\
	(bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT);	\
} while (0)

L
Linus Torvalds 已提交
60 61 62 63
/*
 * various member access, note that bio_data should of course not be used
 * on highmem page vectors
 */
K
Kent Overstreet 已提交
64
#define __bvec_iter_bvec(bvec, iter)	(&(bvec)[(iter).bi_idx])
65

K
Kent Overstreet 已提交
66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95
#define bvec_iter_page(bvec, iter)				\
	(__bvec_iter_bvec((bvec), (iter))->bv_page)

#define bvec_iter_len(bvec, iter)				\
	min((iter).bi_size,					\
	    __bvec_iter_bvec((bvec), (iter))->bv_len - (iter).bi_bvec_done)

#define bvec_iter_offset(bvec, iter)				\
	(__bvec_iter_bvec((bvec), (iter))->bv_offset + (iter).bi_bvec_done)

#define bvec_iter_bvec(bvec, iter)				\
((struct bio_vec) {						\
	.bv_page	= bvec_iter_page((bvec), (iter)),	\
	.bv_len		= bvec_iter_len((bvec), (iter)),	\
	.bv_offset	= bvec_iter_offset((bvec), (iter)),	\
})

#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)
96

97 98
#define bio_multiple_segments(bio)				\
	((bio)->bi_iter.bi_size != bio_iovec(bio).bv_len)
99 100
#define bio_sectors(bio)	((bio)->bi_iter.bi_size >> 9)
#define bio_end_sector(bio)	((bio)->bi_iter.bi_sector + bio_sectors((bio)))
101

102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133
/*
 * 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 &&
	    !(bio->bi_rw & REQ_DISCARD))
		return true;

	return false;
}

static inline bool bio_is_rw(struct bio *bio)
{
	if (!bio_has_data(bio))
		return false;

	if (bio->bi_rw & BIO_NO_ADVANCE_ITER_MASK)
		return false;

	return true;
}

static inline bool bio_mergeable(struct bio *bio)
{
	if (bio->bi_rw & REQ_NOMERGE_FLAGS)
		return false;

	return true;
}

134
static inline unsigned int bio_cur_bytes(struct bio *bio)
135
{
136
	if (bio_has_data(bio))
137
		return bio_iovec(bio).bv_len;
D
David Woodhouse 已提交
138
	else /* dataless requests such as discard */
139
		return bio->bi_iter.bi_size;
140 141 142 143
}

static inline void *bio_data(struct bio *bio)
{
144
	if (bio_has_data(bio))
145 146 147 148
		return page_address(bio_page(bio)) + bio_offset(bio);

	return NULL;
}
L
Linus Torvalds 已提交
149 150 151 152 153 154 155 156 157 158 159 160 161

/*
 * will die
 */
#define bio_to_phys(bio)	(page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
#define bvec_to_phys(bv)	(page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)

/*
 * queues that have highmem support enabled may still need to revert to
 * PIO transfers occasionally and thus map high pages temporarily. For
 * permanent PIO fall back, user is probably better off disabling highmem
 * I/O completely on that queue (see ide-dma for example)
 */
162 163 164
#define __bio_kmap_atomic(bio, iter)				\
	(kmap_atomic(bio_iter_iovec((bio), (iter)).bv_page) +	\
		bio_iter_iovec((bio), (iter)).bv_offset)
L
Linus Torvalds 已提交
165

166
#define __bio_kunmap_atomic(addr)	kunmap_atomic(addr)
L
Linus Torvalds 已提交
167 168 169 170 171

/*
 * merge helpers etc
 */

172 173 174 175
/* Default implementation of BIOVEC_PHYS_MERGEABLE */
#define __BIOVEC_PHYS_MERGEABLE(vec1, vec2)	\
	((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))

L
Linus Torvalds 已提交
176 177 178 179 180
/*
 * allow arch override, for eg virtualized architectures (put in asm/io.h)
 */
#ifndef BIOVEC_PHYS_MERGEABLE
#define BIOVEC_PHYS_MERGEABLE(vec1, vec2)	\
181
	__BIOVEC_PHYS_MERGEABLE(vec1, vec2)
L
Linus Torvalds 已提交
182 183 184 185 186
#endif

#define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
	(((addr1) | (mask)) == (((addr2) - 1) | (mask)))
#define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
187
	__BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q)))
L
Linus Torvalds 已提交
188

189 190 191 192 193 194 195 196 197
/*
 * Check if adding a bio_vec after bprv with offset would create a gap in
 * the SG list. Most drivers don't care about this, but some do.
 */
static inline bool bvec_gap_to_prev(struct bio_vec *bprv, unsigned int offset)
{
	return offset || ((bprv->bv_offset + bprv->bv_len) & (PAGE_SIZE - 1));
}

198
#define bio_io_error(bio) bio_endio((bio), -EIO)
L
Linus Torvalds 已提交
199

200 201 202 203 204
/*
 * 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
 */
#define bio_for_each_segment_all(bvl, bio, i)				\
205
	for (i = 0, bvl = (bio)->bi_io_vec; i < (bio)->bi_vcnt; i++, bvl++)
206

K
Kent Overstreet 已提交
207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227
static inline void bvec_iter_advance(struct bio_vec *bv, struct bvec_iter *iter,
				     unsigned bytes)
{
	WARN_ONCE(bytes > iter->bi_size,
		  "Attempted to advance past end of bvec iter\n");

	while (bytes) {
		unsigned len = min(bytes, bvec_iter_len(bv, *iter));

		bytes -= len;
		iter->bi_size -= len;
		iter->bi_bvec_done += len;

		if (iter->bi_bvec_done == __bvec_iter_bvec(bv, *iter)->bv_len) {
			iter->bi_bvec_done = 0;
			iter->bi_idx++;
		}
	}
}

#define for_each_bvec(bvl, bio_vec, iter, start)			\
M
Martin K. Petersen 已提交
228 229 230
	for (iter = (start);						\
	     (iter).bi_size &&						\
		((bvl = bvec_iter_bvec((bio_vec), (iter))), 1);	\
K
Kent Overstreet 已提交
231 232 233 234 235 236 237 238 239 240 241 242 243 244
	     bvec_iter_advance((bio_vec), &(iter), (bvl).bv_len))


static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter,
				    unsigned bytes)
{
	iter->bi_sector += bytes >> 9;

	if (bio->bi_rw & BIO_NO_ADVANCE_ITER_MASK)
		iter->bi_size -= bytes;
	else
		bvec_iter_advance(bio->bi_io_vec, iter, bytes);
}

245 246
#define __bio_for_each_segment(bvl, bio, iter, start)			\
	for (iter = (start);						\
K
Kent Overstreet 已提交
247 248 249
	     (iter).bi_size &&						\
		((bvl = bio_iter_iovec((bio), (iter))), 1);		\
	     bio_advance_iter((bio), &(iter), (bvl).bv_len))
250 251 252 253

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

K
Kent Overstreet 已提交
254
#define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)
L
Linus Torvalds 已提交
255

256 257 258 259 260 261
static inline unsigned bio_segments(struct bio *bio)
{
	unsigned segs = 0;
	struct bio_vec bv;
	struct bvec_iter iter;

262 263 264 265 266 267 268 269 270 271 272
	/*
	 * We special case discard/write same, because they interpret bi_size
	 * differently:
	 */

	if (bio->bi_rw & REQ_DISCARD)
		return 1;

	if (bio->bi_rw & REQ_WRITE_SAME)
		return 1;

273 274 275 276 277 278
	bio_for_each_segment(bv, bio, iter)
		segs++;

	return segs;
}

L
Linus Torvalds 已提交
279 280 281 282 283 284 285 286 287 288 289 290 291 292
/*
 * 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
 */
293 294 295 296 297 298 299 300 301 302 303 304 305 306 307
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);
		smp_mb__before_atomic();
	}
	atomic_set(&bio->__bi_cnt, count);
}
L
Linus Torvalds 已提交
308

309 310 311 312 313 314 315 316
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 */
};

317
#if defined(CONFIG_BLK_DEV_INTEGRITY)
318 319 320 321 322 323 324 325 326

static inline struct bio_integrity_payload *bio_integrity(struct bio *bio)
{
	if (bio->bi_rw & REQ_INTEGRITY)
		return bio->bi_integrity;

	return NULL;
}

327 328 329 330 331 332
/*
 * bio integrity payload
 */
struct bio_integrity_payload {
	struct bio		*bip_bio;	/* parent bio */

333
	struct bvec_iter	bip_iter;
334

335
	bio_end_io_t		*bip_end_io;	/* saved I/O completion fn */
336

337
	unsigned short		bip_slab;	/* slab the bip came from */
338
	unsigned short		bip_vcnt;	/* # of integrity bio_vecs */
339
	unsigned short		bip_max_vcnt;	/* integrity bio_vec slots */
340
	unsigned short		bip_flags;	/* control flags */
341 342

	struct work_struct	bip_work;	/* I/O completion */
343 344 345

	struct bio_vec		*bip_vec;
	struct bio_vec		bip_inline_vecs[0];/* embedded bvec array */
346
};
347

348 349 350 351 352 353 354 355 356
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;
}
357

358 359 360 361 362 363 364 365 366 367 368
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;
}

369
#endif /* CONFIG_BLK_DEV_INTEGRITY */
L
Linus Torvalds 已提交
370

371
extern void bio_trim(struct bio *bio, int offset, int size);
K
Kent Overstreet 已提交
372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393
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);
}

394
extern struct bio_set *bioset_create(unsigned int, unsigned int);
J
Junichi Nomura 已提交
395
extern struct bio_set *bioset_create_nobvec(unsigned int, unsigned int);
L
Linus Torvalds 已提交
396
extern void bioset_free(struct bio_set *);
397
extern mempool_t *biovec_create_pool(int pool_entries);
L
Linus Torvalds 已提交
398

A
Al Viro 已提交
399
extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
L
Linus Torvalds 已提交
400 401
extern void bio_put(struct bio *);

K
Kent Overstreet 已提交
402 403
extern void __bio_clone_fast(struct bio *, struct bio *);
extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *);
404 405
extern struct bio *bio_clone_bioset(struct bio *, gfp_t, struct bio_set *bs);

406 407 408 409 410 411 412
extern struct bio_set *fs_bio_set;

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

413 414 415 416 417
static inline struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask)
{
	return bio_clone_bioset(bio, gfp_mask, fs_bio_set);
}

418 419 420 421 422
static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
{
	return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
}

423 424 425 426 427 428
static inline struct bio *bio_clone_kmalloc(struct bio *bio, gfp_t gfp_mask)
{
	return bio_clone_bioset(bio, gfp_mask, NULL);

}

429
extern void bio_endio(struct bio *, int);
K
Kent Overstreet 已提交
430
extern void bio_endio_nodec(struct bio *, int);
L
Linus Torvalds 已提交
431 432 433
struct request_queue;
extern int bio_phys_segments(struct request_queue *, struct bio *);

434
extern int submit_bio_wait(int rw, struct bio *bio);
K
Kent Overstreet 已提交
435 436
extern void bio_advance(struct bio *, unsigned);

L
Linus Torvalds 已提交
437
extern void bio_init(struct bio *);
K
Kent Overstreet 已提交
438
extern void bio_reset(struct bio *);
K
Kent Overstreet 已提交
439
void bio_chain(struct bio *, struct bio *);
L
Linus Torvalds 已提交
440 441

extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
442 443
extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
			   unsigned int, unsigned int);
L
Linus Torvalds 已提交
444
extern int bio_get_nr_vecs(struct block_device *);
445
struct rq_map_data;
446
extern struct bio *bio_map_user_iov(struct request_queue *,
447
				    const struct iov_iter *, gfp_t);
L
Linus Torvalds 已提交
448
extern void bio_unmap_user(struct bio *);
M
Mike Christie 已提交
449
extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
A
Al Viro 已提交
450
				gfp_t);
451 452
extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
				 gfp_t, int);
L
Linus Torvalds 已提交
453 454
extern void bio_set_pages_dirty(struct bio *bio);
extern void bio_check_pages_dirty(struct bio *bio);
455

456 457 458 459 460
void generic_start_io_acct(int rw, unsigned long sectors,
			   struct hd_struct *part);
void generic_end_io_acct(int rw, struct hd_struct *part,
			 unsigned long start_time);

461 462 463 464 465 466 467 468 469 470 471
#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
# error	"You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
#endif
#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
extern void bio_flush_dcache_pages(struct bio *bi);
#else
static inline void bio_flush_dcache_pages(struct bio *bi)
{
}
#endif

K
Kent Overstreet 已提交
472
extern void bio_copy_data(struct bio *dst, struct bio *src);
K
Kent Overstreet 已提交
473
extern int bio_alloc_pages(struct bio *bio, gfp_t gfp);
K
Kent Overstreet 已提交
474

475
extern struct bio *bio_copy_user_iov(struct request_queue *,
476
				     struct rq_map_data *,
477 478
				     const struct iov_iter *,
				     gfp_t);
L
Linus Torvalds 已提交
479 480
extern int bio_uncopy_user(struct bio *);
void zero_fill_bio(struct bio *bio);
481 482
extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *);
extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int);
483
extern unsigned int bvec_nr_vecs(unsigned short idx);
484

485 486 487 488 489 490 491 492
#ifdef CONFIG_BLK_CGROUP
int bio_associate_current(struct bio *bio);
void bio_disassociate_task(struct bio *bio);
#else	/* CONFIG_BLK_CGROUP */
static inline int bio_associate_current(struct bio *bio) { return -ENOENT; }
static inline void bio_disassociate_task(struct bio *bio) { }
#endif	/* CONFIG_BLK_CGROUP */

L
Linus Torvalds 已提交
493 494
#ifdef CONFIG_HIGHMEM
/*
495 496
 * remember never ever reenable interrupts between a bvec_kmap_irq and
 * bvec_kunmap_irq!
L
Linus Torvalds 已提交
497
 */
498
static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
L
Linus Torvalds 已提交
499 500 501 502 503 504 505 506
{
	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);
507
	addr = (unsigned long) kmap_atomic(bvec->bv_page);
L
Linus Torvalds 已提交
508 509 510 511 512 513

	BUG_ON(addr & ~PAGE_MASK);

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

514
static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
L
Linus Torvalds 已提交
515 516 517
{
	unsigned long ptr = (unsigned long) buffer & PAGE_MASK;

518
	kunmap_atomic((void *) ptr);
L
Linus Torvalds 已提交
519 520 521 522
	local_irq_restore(*flags);
}

#else
523 524 525 526 527 528 529 530 531
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
532 533
#endif

534
static inline char *__bio_kmap_irq(struct bio *bio, struct bvec_iter iter,
L
Linus Torvalds 已提交
535 536
				   unsigned long *flags)
{
537
	return bvec_kmap_irq(&bio_iter_iovec(bio, iter), flags);
L
Linus Torvalds 已提交
538 539 540 541
}
#define __bio_kunmap_irq(buf, flags)	bvec_kunmap_irq(buf, flags)

#define bio_kmap_irq(bio, flags) \
542
	__bio_kmap_irq((bio), (bio)->bi_iter, (flags))
L
Linus Torvalds 已提交
543 544
#define bio_kunmap_irq(buf,flags)	__bio_kunmap_irq(buf, flags)

545
/*
546
 * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566
 *
 * 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;
}

567 568
#define BIO_EMPTY_LIST	{ NULL, NULL }

569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631
#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
632 633 634 635 636
static inline struct bio *bio_list_peek(struct bio_list *bl)
{
	return bl->head;
}

637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660
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;
}

661 662 663 664 665 666 667 668 669 670 671
/*
 * 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->bi_flags |= (1 << BIO_CHAIN);
	smp_mb__before_atomic();
	atomic_inc(&bio->__bi_remaining);
}

K
Kent Overstreet 已提交
672 673 674 675 676 677 678 679 680 681 682 683 684 685 686
/*
 * 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
#define BIOVEC_NR_POOLS 6
#define BIOVEC_MAX_IDX	(BIOVEC_NR_POOLS - 1)

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

	mempool_t *bio_pool;
687
	mempool_t *bvec_pool;
K
Kent Overstreet 已提交
688 689
#if defined(CONFIG_BLK_DEV_INTEGRITY)
	mempool_t *bio_integrity_pool;
690
	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
701 702 703 704 705 706 707 708 709 710 711 712 713 714
};

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

/*
 * a small number of entries is fine, not going to be performance critical.
 * basically we just need to survive
 */
#define BIO_SPLIT_ENTRIES 2

715 716
#if defined(CONFIG_BLK_DEV_INTEGRITY)

717 718
#define bip_for_each_vec(bvl, bip, iter)				\
	for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
719

720 721 722 723
#define bio_for_each_integrity_vec(_bvl, _bio, _iter)			\
	for_each_bio(_bio)						\
		bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)

724
extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
725
extern void bio_integrity_free(struct bio *);
726
extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
727
extern bool bio_integrity_enabled(struct bio *bio);
728 729 730 731
extern int bio_integrity_prep(struct bio *);
extern void bio_integrity_endio(struct bio *, int);
extern void bio_integrity_advance(struct bio *, unsigned int);
extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
732
extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t);
733 734 735
extern int bioset_integrity_create(struct bio_set *, int);
extern void bioset_integrity_free(struct bio_set *);
extern void bio_integrity_init(void);
736 737 738

#else /* CONFIG_BLK_DEV_INTEGRITY */

739
static inline void *bio_integrity(struct bio *bio)
740
{
741
	return NULL;
742 743
}

744
static inline bool bio_integrity_enabled(struct bio *bio)
745
{
746
	return false;
747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763
}

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;
}

static inline int bio_integrity_prep(struct bio *bio)
{
	return 0;
}

764
static inline void bio_integrity_free(struct bio *bio)
765 766 767 768
{
	return;
}

769
static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
770
				      gfp_t gfp_mask)
771 772 773
{
	return 0;
}
774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790

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

static inline void bio_integrity_trim(struct bio *bio, unsigned int offset,
				      unsigned int sectors)
{
	return;
}

static inline void bio_integrity_init(void)
{
	return;
}
791

792 793 794 795 796
static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
{
	return false;
}

797 798
#endif /* CONFIG_BLK_DEV_INTEGRITY */

799
#endif /* CONFIG_BLOCK */
L
Linus Torvalds 已提交
800
#endif /* __LINUX_BIO_H */