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block: fix blk_rq_append_bio
[linux-block.git] / include / linux / bio.h
CommitLineData
1da177e4 1/*
1da177e4
LT		 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
7cc01581 10 *
1da177e4
LT		 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>
22e2c507 23#include <linux/ioprio.h>
187f1882 24#include <linux/bug.h>
1da177e4 25
02a5e0ac
DH		 26#ifdef CONFIG_BLOCK
27
1da177e4
LT		 28#include <asm/io.h>
29
7cc01581
TH		 30/* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */
31#include <linux/blk_types.h>
32
1da177e4
LT		 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
225311a4
HY		 41#ifdef CONFIG_THP_SWAP
42#if HPAGE_PMD_NR > 256
43#define BIO_MAX_PAGES HPAGE_PMD_NR
44#else
d84a8477 45#define BIO_MAX_PAGES 256
225311a4
HY		 46#endif
47#else
48#define BIO_MAX_PAGES 256
49#endif
1da177e4 50
43b62ce3
MC		 51#define bio_prio(bio) (bio)->bi_ioprio
52#define bio_set_prio(bio, prio) ((bio)->bi_ioprio = prio)
22e2c507 53
4550dd6c
KO		 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)
7988613b 67
458b76ed
KO		 68#define bio_multiple_segments(bio) \
69 ((bio)->bi_iter.bi_size != bio_iovec(bio).bv_len)
4f024f37
KO		 70#define bio_sectors(bio) ((bio)->bi_iter.bi_size >> 9)
71#define bio_end_sector(bio) ((bio)->bi_iter.bi_sector + bio_sectors((bio)))
bf2de6f5 72
d3849953
CH		 73/*
74 * Return the data direction, READ or WRITE.
75 */
76#define bio_data_dir(bio) \
77 (op_is_write(bio_op(bio)) ? WRITE : READ)
78
458b76ed
KO		 79/*
80 * Check whether this bio carries any data or not. A NULL bio is allowed.
81 */
82static inline bool bio_has_data(struct bio *bio)
83{
84 if (bio &&
85 bio->bi_iter.bi_size &&
7afafc8a 86 bio_op(bio) != REQ_OP_DISCARD &&
a6f0788e
CK		 87 bio_op(bio) != REQ_OP_SECURE_ERASE &&
88 bio_op(bio) != REQ_OP_WRITE_ZEROES)
458b76ed
KO		 89 return true;
90
91 return false;
92}
93
95fe6c1a
MC		 94static inline bool bio_no_advance_iter(struct bio *bio)
95{
7afafc8a
AH		 96 return bio_op(bio) == REQ_OP_DISCARD ||
97 bio_op(bio) == REQ_OP_SECURE_ERASE ||
a6f0788e
CK		 98 bio_op(bio) == REQ_OP_WRITE_SAME ||
99 bio_op(bio) == REQ_OP_WRITE_ZEROES;
95fe6c1a
MC		 100}
101
458b76ed
KO		 102static inline bool bio_mergeable(struct bio *bio)
103{
1eff9d32 104 if (bio->bi_opf & REQ_NOMERGE_FLAGS)
458b76ed
KO		 105 return false;
106
107 return true;
108}
109
2e46e8b2 110static inline unsigned int bio_cur_bytes(struct bio *bio)
bf2de6f5 111{
458b76ed 112 if (bio_has_data(bio))
a4ad39b1 113 return bio_iovec(bio).bv_len;
fb2dce86 114 else /* dataless requests such as discard */
4f024f37 115 return bio->bi_iter.bi_size;
bf2de6f5
JA		 116}
117
118static inline void *bio_data(struct bio *bio)
119{
458b76ed 120 if (bio_has_data(bio))
bf2de6f5
JA		 121 return page_address(bio_page(bio)) + bio_offset(bio);
122
123 return NULL;
124}
1da177e4
LT		 125
126/*
127 * will die
128 */
1da177e4
LT		 129#define bvec_to_phys(bv) (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
130
1da177e4
LT		 131/*
132 * merge helpers etc
133 */
134
f92131c3
JF		 135/* Default implementation of BIOVEC_PHYS_MERGEABLE */
136#define __BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
137 ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
138
1da177e4
LT		 139/*
140 * allow arch override, for eg virtualized architectures (put in asm/io.h)
141 */
142#ifndef BIOVEC_PHYS_MERGEABLE
143#define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
f92131c3 144 __BIOVEC_PHYS_MERGEABLE(vec1, vec2)
1da177e4
LT		 145#endif
146
1da177e4
LT		 147#define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
148 (((addr1) | (mask)) == (((addr2) - 1) | (mask)))
149#define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
ae03bf63 150 __BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q)))
1da177e4 151
d74c6d51
KO		 152/*
153 * drivers should _never_ use the all version - the bio may have been split
154 * before it got to the driver and the driver won't own all of it
155 */
156#define bio_for_each_segment_all(bvl, bio, i) \
f619d254 157 for (i = 0, bvl = (bio)->bi_io_vec; i < (bio)->bi_vcnt; i++, bvl++)
d74c6d51 158
4550dd6c
KO		 159static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter,
160 unsigned bytes)
161{
162 iter->bi_sector += bytes >> 9;
163
f9df1cd9 164 if (bio_no_advance_iter(bio)) {
4550dd6c 165 iter->bi_size -= bytes;
f9df1cd9
DM		 166 iter->bi_done += bytes;
167 } else {
4550dd6c 168 bvec_iter_advance(bio->bi_io_vec, iter, bytes);
b1fb2c52
DM		 169 /* TODO: It is reasonable to complete bio with error here. */
170 }
4550dd6c
KO		 171}
172
f9df1cd9
DM		 173static inline bool bio_rewind_iter(struct bio *bio, struct bvec_iter *iter,
174 unsigned int bytes)
175{
176 iter->bi_sector -= bytes >> 9;
177
178 if (bio_no_advance_iter(bio)) {
179 iter->bi_size += bytes;
180 iter->bi_done -= bytes;
181 return true;
182 }
183
184 return bvec_iter_rewind(bio->bi_io_vec, iter, bytes);
185}
186
7988613b
KO		 187#define __bio_for_each_segment(bvl, bio, iter, start) \
188 for (iter = (start); \
4550dd6c
KO		 189 (iter).bi_size && \
190 ((bvl = bio_iter_iovec((bio), (iter))), 1); \
191 bio_advance_iter((bio), &(iter), (bvl).bv_len))
7988613b
KO		 192
193#define bio_for_each_segment(bvl, bio, iter) \
194 __bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter)
195
4550dd6c 196#define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)
1da177e4 197
f4595875 198static inline unsigned bio_segments(struct bio *bio)
458b76ed
KO		 199{
200 unsigned segs = 0;
201 struct bio_vec bv;
202 struct bvec_iter iter;
203
8423ae3d 204 /*
a6f0788e
CK		 205 * We special case discard/write same/write zeroes, because they
206 * interpret bi_size differently:
8423ae3d
KO		 207 */
208
a6f0788e
CK		 209 switch (bio_op(bio)) {
210 case REQ_OP_DISCARD:
211 case REQ_OP_SECURE_ERASE:
a6f0788e 212 case REQ_OP_WRITE_ZEROES:
f9d03f96
CH		 213 return 0;
214 case REQ_OP_WRITE_SAME:
8423ae3d 215 return 1;
a6f0788e
CK		 216 default:
217 break;
218 }
8423ae3d 219
f4595875 220 bio_for_each_segment(bv, bio, iter)
458b76ed
KO		 221 segs++;
222
223 return segs;
224}
225
1da177e4
LT		 226/*
227 * get a reference to a bio, so it won't disappear. the intended use is
228 * something like:
229 *
230 * bio_get(bio);
231 * submit_bio(rw, bio);
232 * if (bio->bi_flags ...)
233 * do_something
234 * bio_put(bio);
235 *
236 * without the bio_get(), it could potentially complete I/O before submit_bio
237 * returns. and then bio would be freed memory when if (bio->bi_flags ...)
238 * runs
239 */
dac56212
JA		 240static inline void bio_get(struct bio *bio)
241{
242 bio->bi_flags |= (1 << BIO_REFFED);
243 smp_mb__before_atomic();
244 atomic_inc(&bio->__bi_cnt);
245}
246
247static inline void bio_cnt_set(struct bio *bio, unsigned int count)
248{
249 if (count != 1) {
250 bio->bi_flags |= (1 << BIO_REFFED);
251 smp_mb__before_atomic();
252 }
253 atomic_set(&bio->__bi_cnt, count);
254}
1da177e4 255
b7c44ed9
JA		 256static inline bool bio_flagged(struct bio *bio, unsigned int bit)
257{
2c68f6dc 258 return (bio->bi_flags & (1U << bit)) != 0;
b7c44ed9
JA		 259}
260
261static inline void bio_set_flag(struct bio *bio, unsigned int bit)
262{
2c68f6dc 263 bio->bi_flags |= (1U << bit);
b7c44ed9
JA		 264}
265
266static inline void bio_clear_flag(struct bio *bio, unsigned int bit)
267{
2c68f6dc 268 bio->bi_flags &= ~(1U << bit);
b7c44ed9
JA		 269}
270
7bcd79ac
ML		 271static inline void bio_get_first_bvec(struct bio *bio, struct bio_vec *bv)
272{
273 *bv = bio_iovec(bio);
274}
275
276static inline void bio_get_last_bvec(struct bio *bio, struct bio_vec *bv)
277{
278 struct bvec_iter iter = bio->bi_iter;
279 int idx;
280
7bcd79ac
ML		 281 if (unlikely(!bio_multiple_segments(bio))) {
282 *bv = bio_iovec(bio);
283 return;
284 }
285
286 bio_advance_iter(bio, &iter, iter.bi_size);
287
288 if (!iter.bi_bvec_done)
289 idx = iter.bi_idx - 1;
290 else /* in the middle of bvec */
291 idx = iter.bi_idx;
292
293 *bv = bio->bi_io_vec[idx];
294
295 /*
296 * iter.bi_bvec_done records actual length of the last bvec
297 * if this bio ends in the middle of one io vector
298 */
299 if (iter.bi_bvec_done)
300 bv->bv_len = iter.bi_bvec_done;
301}
302
c611529e
MP		 303enum bip_flags {
304 BIP_BLOCK_INTEGRITY = 1 << 0, /* block layer owns integrity data */
305 BIP_MAPPED_INTEGRITY = 1 << 1, /* ref tag has been remapped */
306 BIP_CTRL_NOCHECK = 1 << 2, /* disable HBA integrity checking */
307 BIP_DISK_NOCHECK = 1 << 3, /* disable disk integrity checking */
308 BIP_IP_CHECKSUM = 1 << 4, /* IP checksum */
309};
310
7ba1ba12
MP		 311/*
312 * bio integrity payload
313 */
314struct bio_integrity_payload {
315 struct bio *bip_bio; /* parent bio */
7ba1ba12 316
d57a5f7c 317 struct bvec_iter bip_iter;
7ba1ba12 318
7878cba9 319 unsigned short bip_slab; /* slab the bip came from */
7ba1ba12 320 unsigned short bip_vcnt; /* # of integrity bio_vecs */
cbcd1054 321 unsigned short bip_max_vcnt; /* integrity bio_vec slots */
b1f01388 322 unsigned short bip_flags; /* control flags */
7ba1ba12
MP		 323
324 struct work_struct bip_work; /* I/O completion */
6fda981c
KO		 325
326 struct bio_vec *bip_vec;
327 struct bio_vec bip_inline_vecs[0];/* embedded bvec array */
7ba1ba12 328};
18593088 329
06c1e390
KB		 330#if defined(CONFIG_BLK_DEV_INTEGRITY)
331
332static inline struct bio_integrity_payload *bio_integrity(struct bio *bio)
333{
1eff9d32 334 if (bio->bi_opf & REQ_INTEGRITY)
06c1e390
KB		 335 return bio->bi_integrity;
336
337 return NULL;
338}
339
c611529e
MP		 340static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
341{
342 struct bio_integrity_payload *bip = bio_integrity(bio);
343
344 if (bip)
345 return bip->bip_flags & flag;
346
347 return false;
348}
b1f01388 349
18593088
MP		 350static inline sector_t bip_get_seed(struct bio_integrity_payload *bip)
351{
352 return bip->bip_iter.bi_sector;
353}
354
355static inline void bip_set_seed(struct bio_integrity_payload *bip,
356 sector_t seed)
357{
358 bip->bip_iter.bi_sector = seed;
359}
360
7ba1ba12 361#endif /* CONFIG_BLK_DEV_INTEGRITY */
1da177e4 362
6678d83f 363extern void bio_trim(struct bio *bio, int offset, int size);
20d0189b
KO		 364extern struct bio *bio_split(struct bio *bio, int sectors,
365 gfp_t gfp, struct bio_set *bs);
366
367/**
368 * bio_next_split - get next @sectors from a bio, splitting if necessary
369 * @bio: bio to split
370 * @sectors: number of sectors to split from the front of @bio
371 * @gfp: gfp mask
372 * @bs: bio set to allocate from
373 *
374 * Returns a bio representing the next @sectors of @bio - if the bio is smaller
375 * than @sectors, returns the original bio unchanged.
376 */
377static inline struct bio *bio_next_split(struct bio *bio, int sectors,
378 gfp_t gfp, struct bio_set *bs)
379{
380 if (sectors >= bio_sectors(bio))
381 return bio;
382
383 return bio_split(bio, sectors, gfp, bs);
384}
385
011067b0
N		 386extern struct bio_set *bioset_create(unsigned int, unsigned int, int flags);
387enum {
388 BIOSET_NEED_BVECS = BIT(0),
47e0fb46 389 BIOSET_NEED_RESCUER = BIT(1),
011067b0 390};
1da177e4 391extern void bioset_free(struct bio_set *);
a6c39cb4 392extern mempool_t *biovec_create_pool(int pool_entries);
1da177e4 393
7a88fa19 394extern struct bio *bio_alloc_bioset(gfp_t, unsigned int, struct bio_set *);
1da177e4
LT		 395extern void bio_put(struct bio *);
396
59d276fe
KO		 397extern void __bio_clone_fast(struct bio *, struct bio *);
398extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *);
bf800ef1
KO		 399extern struct bio *bio_clone_bioset(struct bio *, gfp_t, struct bio_set *bs);
400
3f86a82a
KO		 401extern struct bio_set *fs_bio_set;
402
403static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
404{
405 return bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set);
406}
407
408static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
409{
410 return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
411}
412
bf800ef1
KO		 413static inline struct bio *bio_clone_kmalloc(struct bio *bio, gfp_t gfp_mask)
414{
415 return bio_clone_bioset(bio, gfp_mask, NULL);
416
417}
418
1e3914d4
CH		 419extern blk_qc_t submit_bio(struct bio *);
420
4246a0b6
CH		 421extern void bio_endio(struct bio *);
422
423static inline void bio_io_error(struct bio *bio)
424{
4e4cbee9 425 bio->bi_status = BLK_STS_IOERR;
4246a0b6
CH		 426 bio_endio(bio);
427}
428
03a07c92
GR		 429static inline void bio_wouldblock_error(struct bio *bio)
430{
431 bio->bi_status = BLK_STS_AGAIN;
4246a0b6
CH		 432 bio_endio(bio);
433}
434
1da177e4
LT		 435struct request_queue;
436extern int bio_phys_segments(struct request_queue *, struct bio *);
1da177e4 437
4e49ea4a 438extern int submit_bio_wait(struct bio *bio);
054bdf64
KO		 439extern void bio_advance(struct bio *, unsigned);
440
3a83f467
ML		 441extern void bio_init(struct bio *bio, struct bio_vec *table,
442 unsigned short max_vecs);
9ae3b3f5 443extern void bio_uninit(struct bio *);
f44b48c7 444extern void bio_reset(struct bio *);
196d38bc 445void bio_chain(struct bio *, struct bio *);
1da177e4
LT		 446
447extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
6e68af66
MC		 448extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
449 unsigned int, unsigned int);
2cefe4db 450int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter);
152e283f 451struct rq_map_data;
f1970baf 452extern struct bio *bio_map_user_iov(struct request_queue *,
e81cef5d 453 struct iov_iter *, gfp_t);
1da177e4 454extern void bio_unmap_user(struct bio *);
df46b9a4 455extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
27496a8c 456 gfp_t);
68154e90
FT		 457extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
458 gfp_t, int);
1da177e4
LT		 459extern void bio_set_pages_dirty(struct bio *bio);
460extern void bio_check_pages_dirty(struct bio *bio);
2d4dc890 461
d62e26b3
JA		 462void generic_start_io_acct(struct request_queue *q, int rw,
463 unsigned long sectors, struct hd_struct *part);
464void generic_end_io_acct(struct request_queue *q, int rw,
465 struct hd_struct *part,
466 unsigned long start_time);
394ffa50 467
2d4dc890
IL		 468#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
469# error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
470#endif
471#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
472extern void bio_flush_dcache_pages(struct bio *bi);
473#else
474static inline void bio_flush_dcache_pages(struct bio *bi)
475{
476}
477#endif
478
16ac3d63 479extern void bio_copy_data(struct bio *dst, struct bio *src);
a0787606 480extern int bio_alloc_pages(struct bio *bio, gfp_t gfp);
491221f8 481extern void bio_free_pages(struct bio *bio);
16ac3d63 482
152e283f 483extern struct bio *bio_copy_user_iov(struct request_queue *,
86d564c8 484 struct rq_map_data *,
e81cef5d 485 struct iov_iter *,
26e49cfc 486 gfp_t);
1da177e4
LT		 487extern int bio_uncopy_user(struct bio *);
488void zero_fill_bio(struct bio *bio);
9f060e22
KO		 489extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *);
490extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int);
7ba1ba12 491extern unsigned int bvec_nr_vecs(unsigned short idx);
51d654e1 492
74d46992
CH		 493#define bio_set_dev(bio, bdev) \
494do { \
495 (bio)->bi_disk = (bdev)->bd_disk; \
496 (bio)->bi_partno = (bdev)->bd_partno; \
497} while (0)
498
499#define bio_copy_dev(dst, src) \
500do { \
501 (dst)->bi_disk = (src)->bi_disk; \
502 (dst)->bi_partno = (src)->bi_partno; \
503} while (0)
504
505#define bio_dev(bio) \
506 disk_devt((bio)->bi_disk)
507
508#define bio_devname(bio, buf) \
509 __bdevname(bio_dev(bio), (buf))
510
852c788f 511#ifdef CONFIG_BLK_CGROUP
1d933cf0 512int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css);
852c788f 513void bio_disassociate_task(struct bio *bio);
20bd723e 514void bio_clone_blkcg_association(struct bio *dst, struct bio *src);
852c788f 515#else /* CONFIG_BLK_CGROUP */
1d933cf0
TH		 516static inline int bio_associate_blkcg(struct bio *bio,
517 struct cgroup_subsys_state *blkcg_css) { return 0; }
852c788f 518static inline void bio_disassociate_task(struct bio *bio) { }
20bd723e
PV		 519static inline void bio_clone_blkcg_association(struct bio *dst,
520 struct bio *src) { }
852c788f
TH		 521#endif /* CONFIG_BLK_CGROUP */
522
1da177e4
LT		 523#ifdef CONFIG_HIGHMEM
524/*
20b636bf
AB		 525 * remember never ever reenable interrupts between a bvec_kmap_irq and
526 * bvec_kunmap_irq!
1da177e4 527 */
4f570f99 528static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
1da177e4
LT		 529{
530 unsigned long addr;
531
532 /*
533 * might not be a highmem page, but the preempt/irq count
534 * balancing is a lot nicer this way
535 */
536 local_irq_save(*flags);
e8e3c3d6 537 addr = (unsigned long) kmap_atomic(bvec->bv_page);
1da177e4
LT		 538
539 BUG_ON(addr & ~PAGE_MASK);
540
541 return (char *) addr + bvec->bv_offset;
542}
543
4f570f99 544static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
1da177e4
LT		 545{
546 unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
547
e8e3c3d6 548 kunmap_atomic((void *) ptr);
1da177e4
LT		 549 local_irq_restore(*flags);
550}
551
552#else
11a691be
GU		 553static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
554{
555 return page_address(bvec->bv_page) + bvec->bv_offset;
556}
557
558static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
559{
560 *flags = 0;
561}
1da177e4
LT		 562#endif
563
8f3d8ba2 564/*
e686307f 565 * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
8f3d8ba2
CH		 566 *
567 * A bio_list anchors a singly-linked list of bios chained through the bi_next
568 * member of the bio. The bio_list also caches the last list member to allow
569 * fast access to the tail.
570 */
571struct bio_list {
572 struct bio *head;
573 struct bio *tail;
574};
575
576static inline int bio_list_empty(const struct bio_list *bl)
577{
578 return bl->head == NULL;
579}
580
581static inline void bio_list_init(struct bio_list *bl)
582{
583 bl->head = bl->tail = NULL;
584}
585
320ae51f
JA		 586#define BIO_EMPTY_LIST { NULL, NULL }
587
8f3d8ba2
CH		 588#define bio_list_for_each(bio, bl) \
589 for (bio = (bl)->head; bio; bio = bio->bi_next)
590
591static inline unsigned bio_list_size(const struct bio_list *bl)
592{
593 unsigned sz = 0;
594 struct bio *bio;
595
596 bio_list_for_each(bio, bl)
597 sz++;
598
599 return sz;
600}
601
602static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
603{
604 bio->bi_next = NULL;
605
606 if (bl->tail)
607 bl->tail->bi_next = bio;
608 else
609 bl->head = bio;
610
611 bl->tail = bio;
612}
613
614static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
615{
616 bio->bi_next = bl->head;
617
618 bl->head = bio;
619
620 if (!bl->tail)
621 bl->tail = bio;
622}
623
624static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
625{
626 if (!bl2->head)
627 return;
628
629 if (bl->tail)
630 bl->tail->bi_next = bl2->head;
631 else
632 bl->head = bl2->head;
633
634 bl->tail = bl2->tail;
635}
636
637static inline void bio_list_merge_head(struct bio_list *bl,
638 struct bio_list *bl2)
639{
640 if (!bl2->head)
641 return;
642
643 if (bl->head)
644 bl2->tail->bi_next = bl->head;
645 else
646 bl->tail = bl2->tail;
647
648 bl->head = bl2->head;
649}
650
13685a16
GU		 651static inline struct bio *bio_list_peek(struct bio_list *bl)
652{
653 return bl->head;
654}
655
8f3d8ba2
CH		 656static inline struct bio *bio_list_pop(struct bio_list *bl)
657{
658 struct bio *bio = bl->head;
659
660 if (bio) {
661 bl->head = bl->head->bi_next;
662 if (!bl->head)
663 bl->tail = NULL;
664
665 bio->bi_next = NULL;
666 }
667
668 return bio;
669}
670
671static inline struct bio *bio_list_get(struct bio_list *bl)
672{
673 struct bio *bio = bl->head;
674
675 bl->head = bl->tail = NULL;
676
677 return bio;
678}
679
0ef5a50c
MS		 680/*
681 * Increment chain count for the bio. Make sure the CHAIN flag update
682 * is visible before the raised count.
683 */
684static inline void bio_inc_remaining(struct bio *bio)
685{
686 bio_set_flag(bio, BIO_CHAIN);
687 smp_mb__before_atomic();
688 atomic_inc(&bio->__bi_remaining);
689}
690
57fb233f
KO		 691/*
692 * bio_set is used to allow other portions of the IO system to
693 * allocate their own private memory pools for bio and iovec structures.
694 * These memory pools in turn all allocate from the bio_slab
695 * and the bvec_slabs[].
696 */
697#define BIO_POOL_SIZE 2
57fb233f
KO		 698
699struct bio_set {
700 struct kmem_cache *bio_slab;
701 unsigned int front_pad;
702
703 mempool_t *bio_pool;
9f060e22 704 mempool_t *bvec_pool;
57fb233f
KO		 705#if defined(CONFIG_BLK_DEV_INTEGRITY)
706 mempool_t *bio_integrity_pool;
9f060e22 707 mempool_t *bvec_integrity_pool;
57fb233f 708#endif
df2cb6da
KO		 709
710 /*
711 * Deadlock avoidance for stacking block drivers: see comments in
712 * bio_alloc_bioset() for details
713 */
714 spinlock_t rescue_lock;
715 struct bio_list rescue_list;
716 struct work_struct rescue_work;
717 struct workqueue_struct *rescue_workqueue;
57fb233f
KO		 718};
719
720struct biovec_slab {
721 int nr_vecs;
722 char *name;
723 struct kmem_cache *slab;
724};
725
726/*
727 * a small number of entries is fine, not going to be performance critical.
728 * basically we just need to survive
729 */
730#define BIO_SPLIT_ENTRIES 2
731
7ba1ba12
MP		 732#if defined(CONFIG_BLK_DEV_INTEGRITY)
733
d57a5f7c
KO		 734#define bip_for_each_vec(bvl, bip, iter) \
735 for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
7ba1ba12 736
13f05c8d
MP		 737#define bio_for_each_integrity_vec(_bvl, _bio, _iter) \
738 for_each_bio(_bio) \
739 bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
740
7ba1ba12 741extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
7ba1ba12 742extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
e23947bd 743extern bool bio_integrity_prep(struct bio *);
7ba1ba12 744extern void bio_integrity_advance(struct bio *, unsigned int);
fbd08e76 745extern void bio_integrity_trim(struct bio *);
1e2a410f 746extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t);
7878cba9
MP		 747extern int bioset_integrity_create(struct bio_set *, int);
748extern void bioset_integrity_free(struct bio_set *);
749extern void bio_integrity_init(void);
7ba1ba12
MP		 750
751#else /* CONFIG_BLK_DEV_INTEGRITY */
752
c611529e 753static inline void *bio_integrity(struct bio *bio)
6898e3bd 754{
c611529e 755 return NULL;
6898e3bd
MP		 756}
757
6898e3bd
MP		 758static inline int bioset_integrity_create(struct bio_set *bs, int pool_size)
759{
760 return 0;
761}
762
763static inline void bioset_integrity_free (struct bio_set *bs)
764{
765 return;
766}
767
e23947bd 768static inline bool bio_integrity_prep(struct bio *bio)
6898e3bd 769{
e23947bd 770 return true;
6898e3bd
MP		 771}
772
0c614e2d 773static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
1e2a410f 774 gfp_t gfp_mask)
0c614e2d
SR		 775{
776 return 0;
777}
6898e3bd 778
6898e3bd
MP		 779static inline void bio_integrity_advance(struct bio *bio,
780 unsigned int bytes_done)
781{
782 return;
783}
784
fbd08e76 785static inline void bio_integrity_trim(struct bio *bio)
6898e3bd
MP		 786{
787 return;
788}
789
790static inline void bio_integrity_init(void)
791{
792 return;
793}
7ba1ba12 794
c611529e
MP		 795static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
796{
797 return false;
798}
799
06c1e390
KB		 800static inline void *bio_integrity_alloc(struct bio * bio, gfp_t gfp,
801 unsigned int nr)
802{
803 return ERR_PTR(-EINVAL);
804}
805
806static inline int bio_integrity_add_page(struct bio *bio, struct page *page,
807 unsigned int len, unsigned int offset)
808{
809 return 0;
810}
811
7ba1ba12
MP		 812#endif /* CONFIG_BLK_DEV_INTEGRITY */
813
02a5e0ac 814#endif /* CONFIG_BLOCK */
1da177e4 815#endif /* __LINUX_BIO_H */
Linux 6.x block layer and io_uring tree(s)