md: raid10: avoid direct access to bvec table in handle_reshape_read_error
[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
d84a8477 41#define BIO_MAX_PAGES 256
1da177e4 42
43b62ce3
MC
43#define bio_prio(bio) (bio)->bi_ioprio
44#define bio_set_prio(bio, prio) ((bio)->bi_ioprio = prio)
22e2c507 45
4550dd6c
KO
46#define bio_iter_iovec(bio, iter) \
47 bvec_iter_bvec((bio)->bi_io_vec, (iter))
48
49#define bio_iter_page(bio, iter) \
50 bvec_iter_page((bio)->bi_io_vec, (iter))
51#define bio_iter_len(bio, iter) \
52 bvec_iter_len((bio)->bi_io_vec, (iter))
53#define bio_iter_offset(bio, iter) \
54 bvec_iter_offset((bio)->bi_io_vec, (iter))
55
56#define bio_page(bio) bio_iter_page((bio), (bio)->bi_iter)
57#define bio_offset(bio) bio_iter_offset((bio), (bio)->bi_iter)
58#define bio_iovec(bio) bio_iter_iovec((bio), (bio)->bi_iter)
7988613b 59
458b76ed
KO
60#define bio_multiple_segments(bio) \
61 ((bio)->bi_iter.bi_size != bio_iovec(bio).bv_len)
4f024f37
KO
62#define bio_sectors(bio) ((bio)->bi_iter.bi_size >> 9)
63#define bio_end_sector(bio) ((bio)->bi_iter.bi_sector + bio_sectors((bio)))
bf2de6f5 64
d3849953
CH
65/*
66 * Return the data direction, READ or WRITE.
67 */
68#define bio_data_dir(bio) \
69 (op_is_write(bio_op(bio)) ? WRITE : READ)
70
458b76ed
KO
71/*
72 * Check whether this bio carries any data or not. A NULL bio is allowed.
73 */
74static inline bool bio_has_data(struct bio *bio)
75{
76 if (bio &&
77 bio->bi_iter.bi_size &&
7afafc8a 78 bio_op(bio) != REQ_OP_DISCARD &&
a6f0788e
CK
79 bio_op(bio) != REQ_OP_SECURE_ERASE &&
80 bio_op(bio) != REQ_OP_WRITE_ZEROES)
458b76ed
KO
81 return true;
82
83 return false;
84}
85
95fe6c1a
MC
86static inline bool bio_no_advance_iter(struct bio *bio)
87{
7afafc8a
AH
88 return bio_op(bio) == REQ_OP_DISCARD ||
89 bio_op(bio) == REQ_OP_SECURE_ERASE ||
a6f0788e
CK
90 bio_op(bio) == REQ_OP_WRITE_SAME ||
91 bio_op(bio) == REQ_OP_WRITE_ZEROES;
95fe6c1a
MC
92}
93
458b76ed
KO
94static inline bool bio_mergeable(struct bio *bio)
95{
1eff9d32 96 if (bio->bi_opf & REQ_NOMERGE_FLAGS)
458b76ed
KO
97 return false;
98
99 return true;
100}
101
2e46e8b2 102static inline unsigned int bio_cur_bytes(struct bio *bio)
bf2de6f5 103{
458b76ed 104 if (bio_has_data(bio))
a4ad39b1 105 return bio_iovec(bio).bv_len;
fb2dce86 106 else /* dataless requests such as discard */
4f024f37 107 return bio->bi_iter.bi_size;
bf2de6f5
JA
108}
109
110static inline void *bio_data(struct bio *bio)
111{
458b76ed 112 if (bio_has_data(bio))
bf2de6f5
JA
113 return page_address(bio_page(bio)) + bio_offset(bio);
114
115 return NULL;
116}
1da177e4
LT
117
118/*
119 * will die
120 */
121#define bio_to_phys(bio) (page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
122#define bvec_to_phys(bv) (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
123
124/*
125 * queues that have highmem support enabled may still need to revert to
126 * PIO transfers occasionally and thus map high pages temporarily. For
127 * permanent PIO fall back, user is probably better off disabling highmem
128 * I/O completely on that queue (see ide-dma for example)
129 */
f619d254
KO
130#define __bio_kmap_atomic(bio, iter) \
131 (kmap_atomic(bio_iter_iovec((bio), (iter)).bv_page) + \
132 bio_iter_iovec((bio), (iter)).bv_offset)
1da177e4 133
f619d254 134#define __bio_kunmap_atomic(addr) kunmap_atomic(addr)
1da177e4
LT
135
136/*
137 * merge helpers etc
138 */
139
f92131c3
JF
140/* Default implementation of BIOVEC_PHYS_MERGEABLE */
141#define __BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
142 ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
143
1da177e4
LT
144/*
145 * allow arch override, for eg virtualized architectures (put in asm/io.h)
146 */
147#ifndef BIOVEC_PHYS_MERGEABLE
148#define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
f92131c3 149 __BIOVEC_PHYS_MERGEABLE(vec1, vec2)
1da177e4
LT
150#endif
151
1da177e4
LT
152#define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
153 (((addr1) | (mask)) == (((addr2) - 1) | (mask)))
154#define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
ae03bf63 155 __BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q)))
1da177e4 156
d74c6d51
KO
157/*
158 * drivers should _never_ use the all version - the bio may have been split
159 * before it got to the driver and the driver won't own all of it
160 */
161#define bio_for_each_segment_all(bvl, bio, i) \
f619d254 162 for (i = 0, bvl = (bio)->bi_io_vec; i < (bio)->bi_vcnt; i++, bvl++)
d74c6d51 163
4550dd6c
KO
164static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter,
165 unsigned bytes)
166{
167 iter->bi_sector += bytes >> 9;
168
95fe6c1a 169 if (bio_no_advance_iter(bio))
4550dd6c
KO
170 iter->bi_size -= bytes;
171 else
172 bvec_iter_advance(bio->bi_io_vec, iter, bytes);
173}
174
7988613b
KO
175#define __bio_for_each_segment(bvl, bio, iter, start) \
176 for (iter = (start); \
4550dd6c
KO
177 (iter).bi_size && \
178 ((bvl = bio_iter_iovec((bio), (iter))), 1); \
179 bio_advance_iter((bio), &(iter), (bvl).bv_len))
7988613b
KO
180
181#define bio_for_each_segment(bvl, bio, iter) \
182 __bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter)
183
4550dd6c 184#define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)
1da177e4 185
c18a1e09 186static inline unsigned __bio_segments(struct bio *bio, struct bvec_iter *bvec)
458b76ed
KO
187{
188 unsigned segs = 0;
189 struct bio_vec bv;
190 struct bvec_iter iter;
191
8423ae3d 192 /*
a6f0788e
CK
193 * We special case discard/write same/write zeroes, because they
194 * interpret bi_size differently:
8423ae3d
KO
195 */
196
a6f0788e
CK
197 switch (bio_op(bio)) {
198 case REQ_OP_DISCARD:
199 case REQ_OP_SECURE_ERASE:
a6f0788e 200 case REQ_OP_WRITE_ZEROES:
f9d03f96
CH
201 return 0;
202 case REQ_OP_WRITE_SAME:
8423ae3d 203 return 1;
a6f0788e
CK
204 default:
205 break;
206 }
8423ae3d 207
c18a1e09 208 __bio_for_each_segment(bv, bio, iter, *bvec)
458b76ed
KO
209 segs++;
210
211 return segs;
212}
213
c18a1e09
ML
214static inline unsigned bio_segments(struct bio *bio)
215{
216 return __bio_segments(bio, &bio->bi_iter);
217}
218
1da177e4
LT
219/*
220 * get a reference to a bio, so it won't disappear. the intended use is
221 * something like:
222 *
223 * bio_get(bio);
224 * submit_bio(rw, bio);
225 * if (bio->bi_flags ...)
226 * do_something
227 * bio_put(bio);
228 *
229 * without the bio_get(), it could potentially complete I/O before submit_bio
230 * returns. and then bio would be freed memory when if (bio->bi_flags ...)
231 * runs
232 */
dac56212
JA
233static inline void bio_get(struct bio *bio)
234{
235 bio->bi_flags |= (1 << BIO_REFFED);
236 smp_mb__before_atomic();
237 atomic_inc(&bio->__bi_cnt);
238}
239
240static inline void bio_cnt_set(struct bio *bio, unsigned int count)
241{
242 if (count != 1) {
243 bio->bi_flags |= (1 << BIO_REFFED);
244 smp_mb__before_atomic();
245 }
246 atomic_set(&bio->__bi_cnt, count);
247}
1da177e4 248
b7c44ed9
JA
249static inline bool bio_flagged(struct bio *bio, unsigned int bit)
250{
2c68f6dc 251 return (bio->bi_flags & (1U << bit)) != 0;
b7c44ed9
JA
252}
253
254static inline void bio_set_flag(struct bio *bio, unsigned int bit)
255{
2c68f6dc 256 bio->bi_flags |= (1U << bit);
b7c44ed9
JA
257}
258
259static inline void bio_clear_flag(struct bio *bio, unsigned int bit)
260{
2c68f6dc 261 bio->bi_flags &= ~(1U << bit);
b7c44ed9
JA
262}
263
7bcd79ac
ML
264static inline void bio_get_first_bvec(struct bio *bio, struct bio_vec *bv)
265{
266 *bv = bio_iovec(bio);
267}
268
269static inline void bio_get_last_bvec(struct bio *bio, struct bio_vec *bv)
270{
271 struct bvec_iter iter = bio->bi_iter;
272 int idx;
273
7bcd79ac
ML
274 if (unlikely(!bio_multiple_segments(bio))) {
275 *bv = bio_iovec(bio);
276 return;
277 }
278
279 bio_advance_iter(bio, &iter, iter.bi_size);
280
281 if (!iter.bi_bvec_done)
282 idx = iter.bi_idx - 1;
283 else /* in the middle of bvec */
284 idx = iter.bi_idx;
285
286 *bv = bio->bi_io_vec[idx];
287
288 /*
289 * iter.bi_bvec_done records actual length of the last bvec
290 * if this bio ends in the middle of one io vector
291 */
292 if (iter.bi_bvec_done)
293 bv->bv_len = iter.bi_bvec_done;
294}
295
c611529e
MP
296enum bip_flags {
297 BIP_BLOCK_INTEGRITY = 1 << 0, /* block layer owns integrity data */
298 BIP_MAPPED_INTEGRITY = 1 << 1, /* ref tag has been remapped */
299 BIP_CTRL_NOCHECK = 1 << 2, /* disable HBA integrity checking */
300 BIP_DISK_NOCHECK = 1 << 3, /* disable disk integrity checking */
301 BIP_IP_CHECKSUM = 1 << 4, /* IP checksum */
302};
303
7ba1ba12
MP
304/*
305 * bio integrity payload
306 */
307struct bio_integrity_payload {
308 struct bio *bip_bio; /* parent bio */
7ba1ba12 309
d57a5f7c 310 struct bvec_iter bip_iter;
7ba1ba12 311
d57a5f7c 312 bio_end_io_t *bip_end_io; /* saved I/O completion fn */
7ba1ba12 313
7878cba9 314 unsigned short bip_slab; /* slab the bip came from */
7ba1ba12 315 unsigned short bip_vcnt; /* # of integrity bio_vecs */
cbcd1054 316 unsigned short bip_max_vcnt; /* integrity bio_vec slots */
b1f01388 317 unsigned short bip_flags; /* control flags */
7ba1ba12
MP
318
319 struct work_struct bip_work; /* I/O completion */
6fda981c
KO
320
321 struct bio_vec *bip_vec;
322 struct bio_vec bip_inline_vecs[0];/* embedded bvec array */
7ba1ba12 323};
18593088 324
06c1e390
KB
325#if defined(CONFIG_BLK_DEV_INTEGRITY)
326
327static inline struct bio_integrity_payload *bio_integrity(struct bio *bio)
328{
1eff9d32 329 if (bio->bi_opf & REQ_INTEGRITY)
06c1e390
KB
330 return bio->bi_integrity;
331
332 return NULL;
333}
334
c611529e
MP
335static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
336{
337 struct bio_integrity_payload *bip = bio_integrity(bio);
338
339 if (bip)
340 return bip->bip_flags & flag;
341
342 return false;
343}
b1f01388 344
18593088
MP
345static inline sector_t bip_get_seed(struct bio_integrity_payload *bip)
346{
347 return bip->bip_iter.bi_sector;
348}
349
350static inline void bip_set_seed(struct bio_integrity_payload *bip,
351 sector_t seed)
352{
353 bip->bip_iter.bi_sector = seed;
354}
355
7ba1ba12 356#endif /* CONFIG_BLK_DEV_INTEGRITY */
1da177e4 357
6678d83f 358extern void bio_trim(struct bio *bio, int offset, int size);
20d0189b
KO
359extern struct bio *bio_split(struct bio *bio, int sectors,
360 gfp_t gfp, struct bio_set *bs);
361
362/**
363 * bio_next_split - get next @sectors from a bio, splitting if necessary
364 * @bio: bio to split
365 * @sectors: number of sectors to split from the front of @bio
366 * @gfp: gfp mask
367 * @bs: bio set to allocate from
368 *
369 * Returns a bio representing the next @sectors of @bio - if the bio is smaller
370 * than @sectors, returns the original bio unchanged.
371 */
372static inline struct bio *bio_next_split(struct bio *bio, int sectors,
373 gfp_t gfp, struct bio_set *bs)
374{
375 if (sectors >= bio_sectors(bio))
376 return bio;
377
378 return bio_split(bio, sectors, gfp, bs);
379}
380
bb799ca0 381extern struct bio_set *bioset_create(unsigned int, unsigned int);
d8f429e1 382extern struct bio_set *bioset_create_nobvec(unsigned int, unsigned int);
1da177e4 383extern void bioset_free(struct bio_set *);
a6c39cb4 384extern mempool_t *biovec_create_pool(int pool_entries);
1da177e4 385
dd0fc66f 386extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
1da177e4
LT
387extern void bio_put(struct bio *);
388
59d276fe
KO
389extern void __bio_clone_fast(struct bio *, struct bio *);
390extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *);
bf800ef1 391extern struct bio *bio_clone_bioset(struct bio *, gfp_t, struct bio_set *bs);
c18a1e09
ML
392extern struct bio *bio_clone_bioset_partial(struct bio *, gfp_t,
393 struct bio_set *, int, int);
bf800ef1 394
3f86a82a
KO
395extern struct bio_set *fs_bio_set;
396
397static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
398{
399 return bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set);
400}
401
bf800ef1
KO
402static inline struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask)
403{
404 return bio_clone_bioset(bio, gfp_mask, fs_bio_set);
405}
406
3f86a82a
KO
407static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
408{
409 return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
410}
411
bf800ef1
KO
412static inline struct bio *bio_clone_kmalloc(struct bio *bio, gfp_t gfp_mask)
413{
414 return bio_clone_bioset(bio, gfp_mask, NULL);
415
416}
417
1e3914d4
CH
418extern blk_qc_t submit_bio(struct bio *);
419
4246a0b6
CH
420extern void bio_endio(struct bio *);
421
422static inline void bio_io_error(struct bio *bio)
423{
424 bio->bi_error = -EIO;
425 bio_endio(bio);
426}
427
1da177e4
LT
428struct request_queue;
429extern int bio_phys_segments(struct request_queue *, struct bio *);
1da177e4 430
4e49ea4a 431extern int submit_bio_wait(struct bio *bio);
054bdf64
KO
432extern void bio_advance(struct bio *, unsigned);
433
3a83f467
ML
434extern void bio_init(struct bio *bio, struct bio_vec *table,
435 unsigned short max_vecs);
f44b48c7 436extern void bio_reset(struct bio *);
196d38bc 437void bio_chain(struct bio *, struct bio *);
1da177e4
LT
438
439extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
6e68af66
MC
440extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
441 unsigned int, unsigned int);
2cefe4db 442int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter);
152e283f 443struct rq_map_data;
f1970baf 444extern struct bio *bio_map_user_iov(struct request_queue *,
26e49cfc 445 const struct iov_iter *, gfp_t);
1da177e4 446extern void bio_unmap_user(struct bio *);
df46b9a4 447extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
27496a8c 448 gfp_t);
68154e90
FT
449extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
450 gfp_t, int);
1da177e4
LT
451extern void bio_set_pages_dirty(struct bio *bio);
452extern void bio_check_pages_dirty(struct bio *bio);
2d4dc890 453
394ffa50
GZ
454void generic_start_io_acct(int rw, unsigned long sectors,
455 struct hd_struct *part);
456void generic_end_io_acct(int rw, struct hd_struct *part,
457 unsigned long start_time);
458
2d4dc890
IL
459#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
460# error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
461#endif
462#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
463extern void bio_flush_dcache_pages(struct bio *bi);
464#else
465static inline void bio_flush_dcache_pages(struct bio *bi)
466{
467}
468#endif
469
16ac3d63 470extern void bio_copy_data(struct bio *dst, struct bio *src);
6f880285
ML
471extern void bio_copy_data_partial(struct bio *dst, struct bio *src,
472 int offset, int size);
a0787606 473extern int bio_alloc_pages(struct bio *bio, gfp_t gfp);
491221f8 474extern void bio_free_pages(struct bio *bio);
16ac3d63 475
152e283f 476extern struct bio *bio_copy_user_iov(struct request_queue *,
86d564c8 477 struct rq_map_data *,
26e49cfc
KO
478 const struct iov_iter *,
479 gfp_t);
1da177e4
LT
480extern int bio_uncopy_user(struct bio *);
481void zero_fill_bio(struct bio *bio);
9f060e22
KO
482extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *);
483extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int);
7ba1ba12 484extern unsigned int bvec_nr_vecs(unsigned short idx);
51d654e1 485
852c788f 486#ifdef CONFIG_BLK_CGROUP
1d933cf0 487int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css);
852c788f
TH
488int bio_associate_current(struct bio *bio);
489void bio_disassociate_task(struct bio *bio);
20bd723e 490void bio_clone_blkcg_association(struct bio *dst, struct bio *src);
852c788f 491#else /* CONFIG_BLK_CGROUP */
1d933cf0
TH
492static inline int bio_associate_blkcg(struct bio *bio,
493 struct cgroup_subsys_state *blkcg_css) { return 0; }
852c788f
TH
494static inline int bio_associate_current(struct bio *bio) { return -ENOENT; }
495static inline void bio_disassociate_task(struct bio *bio) { }
20bd723e
PV
496static inline void bio_clone_blkcg_association(struct bio *dst,
497 struct bio *src) { }
852c788f
TH
498#endif /* CONFIG_BLK_CGROUP */
499
1da177e4
LT
500#ifdef CONFIG_HIGHMEM
501/*
20b636bf
AB
502 * remember never ever reenable interrupts between a bvec_kmap_irq and
503 * bvec_kunmap_irq!
1da177e4 504 */
4f570f99 505static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
1da177e4
LT
506{
507 unsigned long addr;
508
509 /*
510 * might not be a highmem page, but the preempt/irq count
511 * balancing is a lot nicer this way
512 */
513 local_irq_save(*flags);
e8e3c3d6 514 addr = (unsigned long) kmap_atomic(bvec->bv_page);
1da177e4
LT
515
516 BUG_ON(addr & ~PAGE_MASK);
517
518 return (char *) addr + bvec->bv_offset;
519}
520
4f570f99 521static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
1da177e4
LT
522{
523 unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
524
e8e3c3d6 525 kunmap_atomic((void *) ptr);
1da177e4
LT
526 local_irq_restore(*flags);
527}
528
529#else
11a691be
GU
530static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
531{
532 return page_address(bvec->bv_page) + bvec->bv_offset;
533}
534
535static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
536{
537 *flags = 0;
538}
1da177e4
LT
539#endif
540
f619d254 541static inline char *__bio_kmap_irq(struct bio *bio, struct bvec_iter iter,
1da177e4
LT
542 unsigned long *flags)
543{
f619d254 544 return bvec_kmap_irq(&bio_iter_iovec(bio, iter), flags);
1da177e4
LT
545}
546#define __bio_kunmap_irq(buf, flags) bvec_kunmap_irq(buf, flags)
547
548#define bio_kmap_irq(bio, flags) \
f619d254 549 __bio_kmap_irq((bio), (bio)->bi_iter, (flags))
1da177e4
LT
550#define bio_kunmap_irq(buf,flags) __bio_kunmap_irq(buf, flags)
551
8f3d8ba2 552/*
e686307f 553 * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
8f3d8ba2
CH
554 *
555 * A bio_list anchors a singly-linked list of bios chained through the bi_next
556 * member of the bio. The bio_list also caches the last list member to allow
557 * fast access to the tail.
558 */
559struct bio_list {
560 struct bio *head;
561 struct bio *tail;
562};
563
564static inline int bio_list_empty(const struct bio_list *bl)
565{
566 return bl->head == NULL;
567}
568
569static inline void bio_list_init(struct bio_list *bl)
570{
571 bl->head = bl->tail = NULL;
572}
573
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JA
574#define BIO_EMPTY_LIST { NULL, NULL }
575
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CH
576#define bio_list_for_each(bio, bl) \
577 for (bio = (bl)->head; bio; bio = bio->bi_next)
578
579static inline unsigned bio_list_size(const struct bio_list *bl)
580{
581 unsigned sz = 0;
582 struct bio *bio;
583
584 bio_list_for_each(bio, bl)
585 sz++;
586
587 return sz;
588}
589
590static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
591{
592 bio->bi_next = NULL;
593
594 if (bl->tail)
595 bl->tail->bi_next = bio;
596 else
597 bl->head = bio;
598
599 bl->tail = bio;
600}
601
602static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
603{
604 bio->bi_next = bl->head;
605
606 bl->head = bio;
607
608 if (!bl->tail)
609 bl->tail = bio;
610}
611
612static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
613{
614 if (!bl2->head)
615 return;
616
617 if (bl->tail)
618 bl->tail->bi_next = bl2->head;
619 else
620 bl->head = bl2->head;
621
622 bl->tail = bl2->tail;
623}
624
625static inline void bio_list_merge_head(struct bio_list *bl,
626 struct bio_list *bl2)
627{
628 if (!bl2->head)
629 return;
630
631 if (bl->head)
632 bl2->tail->bi_next = bl->head;
633 else
634 bl->tail = bl2->tail;
635
636 bl->head = bl2->head;
637}
638
13685a16
GU
639static inline struct bio *bio_list_peek(struct bio_list *bl)
640{
641 return bl->head;
642}
643
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CH
644static inline struct bio *bio_list_pop(struct bio_list *bl)
645{
646 struct bio *bio = bl->head;
647
648 if (bio) {
649 bl->head = bl->head->bi_next;
650 if (!bl->head)
651 bl->tail = NULL;
652
653 bio->bi_next = NULL;
654 }
655
656 return bio;
657}
658
659static inline struct bio *bio_list_get(struct bio_list *bl)
660{
661 struct bio *bio = bl->head;
662
663 bl->head = bl->tail = NULL;
664
665 return bio;
666}
667
0ef5a50c
MS
668/*
669 * Increment chain count for the bio. Make sure the CHAIN flag update
670 * is visible before the raised count.
671 */
672static inline void bio_inc_remaining(struct bio *bio)
673{
674 bio_set_flag(bio, BIO_CHAIN);
675 smp_mb__before_atomic();
676 atomic_inc(&bio->__bi_remaining);
677}
678
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KO
679/*
680 * bio_set is used to allow other portions of the IO system to
681 * allocate their own private memory pools for bio and iovec structures.
682 * These memory pools in turn all allocate from the bio_slab
683 * and the bvec_slabs[].
684 */
685#define BIO_POOL_SIZE 2
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686
687struct bio_set {
688 struct kmem_cache *bio_slab;
689 unsigned int front_pad;
690
691 mempool_t *bio_pool;
9f060e22 692 mempool_t *bvec_pool;
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KO
693#if defined(CONFIG_BLK_DEV_INTEGRITY)
694 mempool_t *bio_integrity_pool;
9f060e22 695 mempool_t *bvec_integrity_pool;
57fb233f 696#endif
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KO
697
698 /*
699 * Deadlock avoidance for stacking block drivers: see comments in
700 * bio_alloc_bioset() for details
701 */
702 spinlock_t rescue_lock;
703 struct bio_list rescue_list;
704 struct work_struct rescue_work;
705 struct workqueue_struct *rescue_workqueue;
57fb233f
KO
706};
707
708struct biovec_slab {
709 int nr_vecs;
710 char *name;
711 struct kmem_cache *slab;
712};
713
714/*
715 * a small number of entries is fine, not going to be performance critical.
716 * basically we just need to survive
717 */
718#define BIO_SPLIT_ENTRIES 2
719
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MP
720#if defined(CONFIG_BLK_DEV_INTEGRITY)
721
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KO
722#define bip_for_each_vec(bvl, bip, iter) \
723 for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
7ba1ba12 724
13f05c8d
MP
725#define bio_for_each_integrity_vec(_bvl, _bio, _iter) \
726 for_each_bio(_bio) \
727 bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
728
7ba1ba12 729extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
1e2a410f 730extern void bio_integrity_free(struct bio *);
7ba1ba12 731extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
e7258c1a 732extern bool bio_integrity_enabled(struct bio *bio);
7ba1ba12 733extern int bio_integrity_prep(struct bio *);
4246a0b6 734extern void bio_integrity_endio(struct bio *);
7ba1ba12
MP
735extern void bio_integrity_advance(struct bio *, unsigned int);
736extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
1e2a410f 737extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t);
7878cba9
MP
738extern int bioset_integrity_create(struct bio_set *, int);
739extern void bioset_integrity_free(struct bio_set *);
740extern void bio_integrity_init(void);
7ba1ba12
MP
741
742#else /* CONFIG_BLK_DEV_INTEGRITY */
743
c611529e 744static inline void *bio_integrity(struct bio *bio)
6898e3bd 745{
c611529e 746 return NULL;
6898e3bd
MP
747}
748
e7258c1a 749static inline bool bio_integrity_enabled(struct bio *bio)
6898e3bd 750{
e7258c1a 751 return false;
6898e3bd
MP
752}
753
754static inline int bioset_integrity_create(struct bio_set *bs, int pool_size)
755{
756 return 0;
757}
758
759static inline void bioset_integrity_free (struct bio_set *bs)
760{
761 return;
762}
763
764static inline int bio_integrity_prep(struct bio *bio)
765{
766 return 0;
767}
768
1e2a410f 769static inline void bio_integrity_free(struct bio *bio)
6898e3bd
MP
770{
771 return;
772}
773
0c614e2d 774static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
1e2a410f 775 gfp_t gfp_mask)
0c614e2d
SR
776{
777 return 0;
778}
6898e3bd 779
6898e3bd
MP
780static inline void bio_integrity_advance(struct bio *bio,
781 unsigned int bytes_done)
782{
783 return;
784}
785
786static inline void bio_integrity_trim(struct bio *bio, unsigned int offset,
787 unsigned int sectors)
788{
789 return;
790}
791
792static inline void bio_integrity_init(void)
793{
794 return;
795}
7ba1ba12 796
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MP
797static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
798{
799 return false;
800}
801
06c1e390
KB
802static inline void *bio_integrity_alloc(struct bio * bio, gfp_t gfp,
803 unsigned int nr)
804{
805 return ERR_PTR(-EINVAL);
806}
807
808static inline int bio_integrity_add_page(struct bio *bio, struct page *page,
809 unsigned int len, unsigned int offset)
810{
811 return 0;
812}
813
7ba1ba12
MP
814#endif /* CONFIG_BLK_DEV_INTEGRITY */
815
02a5e0ac 816#endif /* CONFIG_BLOCK */
1da177e4 817#endif /* __LINUX_BIO_H */