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Linux 4.3-rc2
[deliverable/linux.git] / include / linux / bio.h
CommitLineData
1da177e4
LT		 1/*
2 * 2.5 block I/O model
3 *
4 * Copyright (C) 2001 Jens Axboe <axboe@suse.de>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
7cc01581 12 *
1da177e4
LT		 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public Licens
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-
19 */
20#ifndef __LINUX_BIO_H
21#define __LINUX_BIO_H
22
23#include <linux/highmem.h>
24#include <linux/mempool.h>
22e2c507 25#include <linux/ioprio.h>
187f1882 26#include <linux/bug.h>
1da177e4 27
02a5e0ac
DH		 28#ifdef CONFIG_BLOCK
29
1da177e4
LT		 30#include <asm/io.h>
31
7cc01581
TH		 32/* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */
33#include <linux/blk_types.h>
34
1da177e4
LT		 35#define BIO_DEBUG
36
37#ifdef BIO_DEBUG
38#define BIO_BUG_ON BUG_ON
39#else
40#define BIO_BUG_ON
41#endif
42
d84a8477 43#define BIO_MAX_PAGES 256
1da177e4
LT		 44#define BIO_MAX_SIZE (BIO_MAX_PAGES << PAGE_CACHE_SHIFT)
45#define BIO_MAX_SECTORS (BIO_MAX_SIZE >> 9)
46
22e2c507
JA		 47/*
48 * upper 16 bits of bi_rw define the io priority of this bio
49 */
50#define BIO_PRIO_SHIFT (8 * sizeof(unsigned long) - IOPRIO_BITS)
51#define bio_prio(bio) ((bio)->bi_rw >> BIO_PRIO_SHIFT)
52#define bio_prio_valid(bio) ioprio_valid(bio_prio(bio))
53
54#define bio_set_prio(bio, prio) do { \
55 WARN_ON(prio >= (1 << IOPRIO_BITS)); \
56 (bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1); \
57 (bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT); \
58} while (0)
59
1da177e4
LT		 60/*
61 * various member access, note that bio_data should of course not be used
62 * on highmem page vectors
63 */
4550dd6c 64#define __bvec_iter_bvec(bvec, iter) (&(bvec)[(iter).bi_idx])
a4ad39b1 65
4550dd6c
KO		 66#define bvec_iter_page(bvec, iter) \
67 (__bvec_iter_bvec((bvec), (iter))->bv_page)
68
69#define bvec_iter_len(bvec, iter) \
70 min((iter).bi_size, \
71 __bvec_iter_bvec((bvec), (iter))->bv_len - (iter).bi_bvec_done)
72
73#define bvec_iter_offset(bvec, iter) \
74 (__bvec_iter_bvec((bvec), (iter))->bv_offset + (iter).bi_bvec_done)
75
76#define bvec_iter_bvec(bvec, iter) \
77((struct bio_vec) { \
78 .bv_page = bvec_iter_page((bvec), (iter)), \
79 .bv_len = bvec_iter_len((bvec), (iter)), \
80 .bv_offset = bvec_iter_offset((bvec), (iter)), \
81})
82
83#define bio_iter_iovec(bio, iter) \
84 bvec_iter_bvec((bio)->bi_io_vec, (iter))
85
86#define bio_iter_page(bio, iter) \
87 bvec_iter_page((bio)->bi_io_vec, (iter))
88#define bio_iter_len(bio, iter) \
89 bvec_iter_len((bio)->bi_io_vec, (iter))
90#define bio_iter_offset(bio, iter) \
91 bvec_iter_offset((bio)->bi_io_vec, (iter))
92
93#define bio_page(bio) bio_iter_page((bio), (bio)->bi_iter)
94#define bio_offset(bio) bio_iter_offset((bio), (bio)->bi_iter)
95#define bio_iovec(bio) bio_iter_iovec((bio), (bio)->bi_iter)
7988613b 96
458b76ed
KO		 97#define bio_multiple_segments(bio) \
98 ((bio)->bi_iter.bi_size != bio_iovec(bio).bv_len)
4f024f37
KO		 99#define bio_sectors(bio) ((bio)->bi_iter.bi_size >> 9)
100#define bio_end_sector(bio) ((bio)->bi_iter.bi_sector + bio_sectors((bio)))
bf2de6f5 101
458b76ed
KO		 102/*
103 * Check whether this bio carries any data or not. A NULL bio is allowed.
104 */
105static inline bool bio_has_data(struct bio *bio)
106{
107 if (bio &&
108 bio->bi_iter.bi_size &&
109 !(bio->bi_rw & REQ_DISCARD))
110 return true;
111
112 return false;
113}
114
115static inline bool bio_is_rw(struct bio *bio)
116{
117 if (!bio_has_data(bio))
118 return false;
119
120 if (bio->bi_rw & BIO_NO_ADVANCE_ITER_MASK)
121 return false;
122
123 return true;
124}
125
126static inline bool bio_mergeable(struct bio *bio)
127{
128 if (bio->bi_rw & REQ_NOMERGE_FLAGS)
129 return false;
130
131 return true;
132}
133
2e46e8b2 134static inline unsigned int bio_cur_bytes(struct bio *bio)
bf2de6f5 135{
458b76ed 136 if (bio_has_data(bio))
a4ad39b1 137 return bio_iovec(bio).bv_len;
fb2dce86 138 else /* dataless requests such as discard */
4f024f37 139 return bio->bi_iter.bi_size;
bf2de6f5
JA		 140}
141
142static inline void *bio_data(struct bio *bio)
143{
458b76ed 144 if (bio_has_data(bio))
bf2de6f5
JA		 145 return page_address(bio_page(bio)) + bio_offset(bio);
146
147 return NULL;
148}
1da177e4
LT		 149
150/*
151 * will die
152 */
153#define bio_to_phys(bio) (page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
154#define bvec_to_phys(bv) (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
155
156/*
157 * queues that have highmem support enabled may still need to revert to
158 * PIO transfers occasionally and thus map high pages temporarily. For
159 * permanent PIO fall back, user is probably better off disabling highmem
160 * I/O completely on that queue (see ide-dma for example)
161 */
f619d254
KO		 162#define __bio_kmap_atomic(bio, iter) \
163 (kmap_atomic(bio_iter_iovec((bio), (iter)).bv_page) + \
164 bio_iter_iovec((bio), (iter)).bv_offset)
1da177e4 165
f619d254 166#define __bio_kunmap_atomic(addr) kunmap_atomic(addr)
1da177e4
LT		 167
168/*
169 * merge helpers etc
170 */
171
f92131c3
JF		 172/* Default implementation of BIOVEC_PHYS_MERGEABLE */
173#define __BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
174 ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
175
1da177e4
LT		 176/*
177 * allow arch override, for eg virtualized architectures (put in asm/io.h)
178 */
179#ifndef BIOVEC_PHYS_MERGEABLE
180#define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
f92131c3 181 __BIOVEC_PHYS_MERGEABLE(vec1, vec2)
1da177e4
LT		 182#endif
183
1da177e4
LT		 184#define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
185 (((addr1) | (mask)) == (((addr2) - 1) | (mask)))
186#define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
ae03bf63 187 __BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q)))
1da177e4 188
d74c6d51
KO		 189/*
190 * drivers should _never_ use the all version - the bio may have been split
191 * before it got to the driver and the driver won't own all of it
192 */
193#define bio_for_each_segment_all(bvl, bio, i) \
f619d254 194 for (i = 0, bvl = (bio)->bi_io_vec; i < (bio)->bi_vcnt; i++, bvl++)
d74c6d51 195
4550dd6c
KO		 196static inline void bvec_iter_advance(struct bio_vec *bv, struct bvec_iter *iter,
197 unsigned bytes)
198{
199 WARN_ONCE(bytes > iter->bi_size,
200 "Attempted to advance past end of bvec iter\n");
201
202 while (bytes) {
203 unsigned len = min(bytes, bvec_iter_len(bv, *iter));
204
205 bytes -= len;
206 iter->bi_size -= len;
207 iter->bi_bvec_done += len;
208
209 if (iter->bi_bvec_done == __bvec_iter_bvec(bv, *iter)->bv_len) {
210 iter->bi_bvec_done = 0;
211 iter->bi_idx++;
212 }
213 }
214}
215
216#define for_each_bvec(bvl, bio_vec, iter, start) \
b7aa84d9
MP		 217 for (iter = (start); \
218 (iter).bi_size && \
219 ((bvl = bvec_iter_bvec((bio_vec), (iter))), 1); \
4550dd6c
KO		 220 bvec_iter_advance((bio_vec), &(iter), (bvl).bv_len))
221
222
223static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter,
224 unsigned bytes)
225{
226 iter->bi_sector += bytes >> 9;
227
228 if (bio->bi_rw & BIO_NO_ADVANCE_ITER_MASK)
229 iter->bi_size -= bytes;
230 else
231 bvec_iter_advance(bio->bi_io_vec, iter, bytes);
232}
233
7988613b
KO		 234#define __bio_for_each_segment(bvl, bio, iter, start) \
235 for (iter = (start); \
4550dd6c
KO		 236 (iter).bi_size && \
237 ((bvl = bio_iter_iovec((bio), (iter))), 1); \
238 bio_advance_iter((bio), &(iter), (bvl).bv_len))
7988613b
KO		 239
240#define bio_for_each_segment(bvl, bio, iter) \
241 __bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter)
242
4550dd6c 243#define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)
1da177e4 244
458b76ed
KO		 245static inline unsigned bio_segments(struct bio *bio)
246{
247 unsigned segs = 0;
248 struct bio_vec bv;
249 struct bvec_iter iter;
250
8423ae3d
KO		 251 /*
252 * We special case discard/write same, because they interpret bi_size
253 * differently:
254 */
255
256 if (bio->bi_rw & REQ_DISCARD)
257 return 1;
258
259 if (bio->bi_rw & REQ_WRITE_SAME)
260 return 1;
261
458b76ed
KO		 262 bio_for_each_segment(bv, bio, iter)
263 segs++;
264
265 return segs;
266}
267
1da177e4
LT		 268/*
269 * get a reference to a bio, so it won't disappear. the intended use is
270 * something like:
271 *
272 * bio_get(bio);
273 * submit_bio(rw, bio);
274 * if (bio->bi_flags ...)
275 * do_something
276 * bio_put(bio);
277 *
278 * without the bio_get(), it could potentially complete I/O before submit_bio
279 * returns. and then bio would be freed memory when if (bio->bi_flags ...)
280 * runs
281 */
dac56212
JA		 282static inline void bio_get(struct bio *bio)
283{
284 bio->bi_flags |= (1 << BIO_REFFED);
285 smp_mb__before_atomic();
286 atomic_inc(&bio->__bi_cnt);
287}
288
289static inline void bio_cnt_set(struct bio *bio, unsigned int count)
290{
291 if (count != 1) {
292 bio->bi_flags |= (1 << BIO_REFFED);
293 smp_mb__before_atomic();
294 }
295 atomic_set(&bio->__bi_cnt, count);
296}
1da177e4 297
b7c44ed9
JA		 298static inline bool bio_flagged(struct bio *bio, unsigned int bit)
299{
2c68f6dc 300 return (bio->bi_flags & (1U << bit)) != 0;
b7c44ed9
JA		 301}
302
303static inline void bio_set_flag(struct bio *bio, unsigned int bit)
304{
2c68f6dc 305 bio->bi_flags |= (1U << bit);
b7c44ed9
JA		 306}
307
308static inline void bio_clear_flag(struct bio *bio, unsigned int bit)
309{
2c68f6dc 310 bio->bi_flags &= ~(1U << bit);
b7c44ed9
JA		 311}
312
c611529e
MP		 313enum bip_flags {
314 BIP_BLOCK_INTEGRITY = 1 << 0, /* block layer owns integrity data */
315 BIP_MAPPED_INTEGRITY = 1 << 1, /* ref tag has been remapped */
316 BIP_CTRL_NOCHECK = 1 << 2, /* disable HBA integrity checking */
317 BIP_DISK_NOCHECK = 1 << 3, /* disable disk integrity checking */
318 BIP_IP_CHECKSUM = 1 << 4, /* IP checksum */
319};
320
7ba1ba12 321#if defined(CONFIG_BLK_DEV_INTEGRITY)
180b2f95
MP		 322
323static inline struct bio_integrity_payload *bio_integrity(struct bio *bio)
324{
325 if (bio->bi_rw & REQ_INTEGRITY)
326 return bio->bi_integrity;
327
328 return NULL;
329}
330
7ba1ba12
MP		 331/*
332 * bio integrity payload
333 */
334struct bio_integrity_payload {
335 struct bio *bip_bio; /* parent bio */
7ba1ba12 336
d57a5f7c 337 struct bvec_iter bip_iter;
7ba1ba12 338
d57a5f7c 339 bio_end_io_t *bip_end_io; /* saved I/O completion fn */
7ba1ba12 340
7878cba9 341 unsigned short bip_slab; /* slab the bip came from */
7ba1ba12 342 unsigned short bip_vcnt; /* # of integrity bio_vecs */
cbcd1054 343 unsigned short bip_max_vcnt; /* integrity bio_vec slots */
b1f01388 344 unsigned short bip_flags; /* control flags */
7ba1ba12
MP		 345
346 struct work_struct bip_work; /* I/O completion */
6fda981c
KO		 347
348 struct bio_vec *bip_vec;
349 struct bio_vec bip_inline_vecs[0];/* embedded bvec array */
7ba1ba12 350};
18593088 351
c611529e
MP		 352static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
353{
354 struct bio_integrity_payload *bip = bio_integrity(bio);
355
356 if (bip)
357 return bip->bip_flags & flag;
358
359 return false;
360}
b1f01388 361
18593088
MP		 362static inline sector_t bip_get_seed(struct bio_integrity_payload *bip)
363{
364 return bip->bip_iter.bi_sector;
365}
366
367static inline void bip_set_seed(struct bio_integrity_payload *bip,
368 sector_t seed)
369{
370 bip->bip_iter.bi_sector = seed;
371}
372
7ba1ba12 373#endif /* CONFIG_BLK_DEV_INTEGRITY */
1da177e4 374
6678d83f 375extern void bio_trim(struct bio *bio, int offset, int size);
20d0189b
KO		 376extern struct bio *bio_split(struct bio *bio, int sectors,
377 gfp_t gfp, struct bio_set *bs);
378
379/**
380 * bio_next_split - get next @sectors from a bio, splitting if necessary
381 * @bio: bio to split
382 * @sectors: number of sectors to split from the front of @bio
383 * @gfp: gfp mask
384 * @bs: bio set to allocate from
385 *
386 * Returns a bio representing the next @sectors of @bio - if the bio is smaller
387 * than @sectors, returns the original bio unchanged.
388 */
389static inline struct bio *bio_next_split(struct bio *bio, int sectors,
390 gfp_t gfp, struct bio_set *bs)
391{
392 if (sectors >= bio_sectors(bio))
393 return bio;
394
395 return bio_split(bio, sectors, gfp, bs);
396}
397
bb799ca0 398extern struct bio_set *bioset_create(unsigned int, unsigned int);
d8f429e1 399extern struct bio_set *bioset_create_nobvec(unsigned int, unsigned int);
1da177e4 400extern void bioset_free(struct bio_set *);
a6c39cb4 401extern mempool_t *biovec_create_pool(int pool_entries);
1da177e4 402
dd0fc66f 403extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
1da177e4
LT		 404extern void bio_put(struct bio *);
405
59d276fe
KO		 406extern void __bio_clone_fast(struct bio *, struct bio *);
407extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *);
bf800ef1
KO		 408extern struct bio *bio_clone_bioset(struct bio *, gfp_t, struct bio_set *bs);
409
3f86a82a
KO		 410extern struct bio_set *fs_bio_set;
411
412static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
413{
414 return bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set);
415}
416
bf800ef1
KO		 417static inline struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask)
418{
419 return bio_clone_bioset(bio, gfp_mask, fs_bio_set);
420}
421
3f86a82a
KO		 422static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
423{
424 return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
425}
426
bf800ef1
KO		 427static inline struct bio *bio_clone_kmalloc(struct bio *bio, gfp_t gfp_mask)
428{
429 return bio_clone_bioset(bio, gfp_mask, NULL);
430
431}
432
4246a0b6
CH		 433extern void bio_endio(struct bio *);
434
435static inline void bio_io_error(struct bio *bio)
436{
437 bio->bi_error = -EIO;
438 bio_endio(bio);
439}
440
1da177e4
LT		 441struct request_queue;
442extern int bio_phys_segments(struct request_queue *, struct bio *);
1da177e4 443
9e882242 444extern int submit_bio_wait(int rw, struct bio *bio);
054bdf64
KO		 445extern void bio_advance(struct bio *, unsigned);
446
1da177e4 447extern void bio_init(struct bio *);
f44b48c7 448extern void bio_reset(struct bio *);
196d38bc 449void bio_chain(struct bio *, struct bio *);
1da177e4
LT		 450
451extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
6e68af66
MC		 452extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
453 unsigned int, unsigned int);
152e283f 454struct rq_map_data;
f1970baf 455extern struct bio *bio_map_user_iov(struct request_queue *,
26e49cfc 456 const struct iov_iter *, gfp_t);
1da177e4 457extern void bio_unmap_user(struct bio *);
df46b9a4 458extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
27496a8c 459 gfp_t);
68154e90
FT		 460extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
461 gfp_t, int);
1da177e4
LT		 462extern void bio_set_pages_dirty(struct bio *bio);
463extern void bio_check_pages_dirty(struct bio *bio);
2d4dc890 464
394ffa50
GZ		 465void generic_start_io_acct(int rw, unsigned long sectors,
466 struct hd_struct *part);
467void generic_end_io_acct(int rw, struct hd_struct *part,
468 unsigned long start_time);
469
2d4dc890
IL		 470#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
471# error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
472#endif
473#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
474extern void bio_flush_dcache_pages(struct bio *bi);
475#else
476static inline void bio_flush_dcache_pages(struct bio *bi)
477{
478}
479#endif
480
16ac3d63 481extern void bio_copy_data(struct bio *dst, struct bio *src);
a0787606 482extern int bio_alloc_pages(struct bio *bio, gfp_t gfp);
16ac3d63 483
152e283f 484extern struct bio *bio_copy_user_iov(struct request_queue *,
86d564c8 485 struct rq_map_data *,
26e49cfc
KO		 486 const struct iov_iter *,
487 gfp_t);
1da177e4
LT		 488extern int bio_uncopy_user(struct bio *);
489void zero_fill_bio(struct bio *bio);
9f060e22
KO		 490extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *);
491extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int);
7ba1ba12 492extern unsigned int bvec_nr_vecs(unsigned short idx);
51d654e1 493
852c788f 494#ifdef CONFIG_BLK_CGROUP
1d933cf0 495int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css);
852c788f
TH		 496int bio_associate_current(struct bio *bio);
497void bio_disassociate_task(struct bio *bio);
498#else /* CONFIG_BLK_CGROUP */
1d933cf0
TH		 499static inline int bio_associate_blkcg(struct bio *bio,
500 struct cgroup_subsys_state *blkcg_css) { return 0; }
852c788f
TH		 501static inline int bio_associate_current(struct bio *bio) { return -ENOENT; }
502static inline void bio_disassociate_task(struct bio *bio) { }
503#endif /* CONFIG_BLK_CGROUP */
504
1da177e4
LT		 505#ifdef CONFIG_HIGHMEM
506/*
20b636bf
AB		 507 * remember never ever reenable interrupts between a bvec_kmap_irq and
508 * bvec_kunmap_irq!
1da177e4 509 */
4f570f99 510static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
1da177e4
LT		 511{
512 unsigned long addr;
513
514 /*
515 * might not be a highmem page, but the preempt/irq count
516 * balancing is a lot nicer this way
517 */
518 local_irq_save(*flags);
e8e3c3d6 519 addr = (unsigned long) kmap_atomic(bvec->bv_page);
1da177e4
LT		 520
521 BUG_ON(addr & ~PAGE_MASK);
522
523 return (char *) addr + bvec->bv_offset;
524}
525
4f570f99 526static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
1da177e4
LT		 527{
528 unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
529
e8e3c3d6 530 kunmap_atomic((void *) ptr);
1da177e4
LT		 531 local_irq_restore(*flags);
532}
533
534#else
11a691be
GU		 535static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
536{
537 return page_address(bvec->bv_page) + bvec->bv_offset;
538}
539
540static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
541{
542 *flags = 0;
543}
1da177e4
LT		 544#endif
545
f619d254 546static inline char *__bio_kmap_irq(struct bio *bio, struct bvec_iter iter,
1da177e4
LT		 547 unsigned long *flags)
548{
f619d254 549 return bvec_kmap_irq(&bio_iter_iovec(bio, iter), flags);
1da177e4
LT		 550}
551#define __bio_kunmap_irq(buf, flags) bvec_kunmap_irq(buf, flags)
552
553#define bio_kmap_irq(bio, flags) \
f619d254 554 __bio_kmap_irq((bio), (bio)->bi_iter, (flags))
1da177e4
LT		 555#define bio_kunmap_irq(buf,flags) __bio_kunmap_irq(buf, flags)
556
8f3d8ba2 557/*
e686307f 558 * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
8f3d8ba2
CH		 559 *
560 * A bio_list anchors a singly-linked list of bios chained through the bi_next
561 * member of the bio. The bio_list also caches the last list member to allow
562 * fast access to the tail.
563 */
564struct bio_list {
565 struct bio *head;
566 struct bio *tail;
567};
568
569static inline int bio_list_empty(const struct bio_list *bl)
570{
571 return bl->head == NULL;
572}
573
574static inline void bio_list_init(struct bio_list *bl)
575{
576 bl->head = bl->tail = NULL;
577}
578
320ae51f
JA		 579#define BIO_EMPTY_LIST { NULL, NULL }
580
8f3d8ba2
CH		 581#define bio_list_for_each(bio, bl) \
582 for (bio = (bl)->head; bio; bio = bio->bi_next)
583
584static inline unsigned bio_list_size(const struct bio_list *bl)
585{
586 unsigned sz = 0;
587 struct bio *bio;
588
589 bio_list_for_each(bio, bl)
590 sz++;
591
592 return sz;
593}
594
595static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
596{
597 bio->bi_next = NULL;
598
599 if (bl->tail)
600 bl->tail->bi_next = bio;
601 else
602 bl->head = bio;
603
604 bl->tail = bio;
605}
606
607static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
608{
609 bio->bi_next = bl->head;
610
611 bl->head = bio;
612
613 if (!bl->tail)
614 bl->tail = bio;
615}
616
617static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
618{
619 if (!bl2->head)
620 return;
621
622 if (bl->tail)
623 bl->tail->bi_next = bl2->head;
624 else
625 bl->head = bl2->head;
626
627 bl->tail = bl2->tail;
628}
629
630static inline void bio_list_merge_head(struct bio_list *bl,
631 struct bio_list *bl2)
632{
633 if (!bl2->head)
634 return;
635
636 if (bl->head)
637 bl2->tail->bi_next = bl->head;
638 else
639 bl->tail = bl2->tail;
640
641 bl->head = bl2->head;
642}
643
13685a16
GU		 644static inline struct bio *bio_list_peek(struct bio_list *bl)
645{
646 return bl->head;
647}
648
8f3d8ba2
CH		 649static inline struct bio *bio_list_pop(struct bio_list *bl)
650{
651 struct bio *bio = bl->head;
652
653 if (bio) {
654 bl->head = bl->head->bi_next;
655 if (!bl->head)
656 bl->tail = NULL;
657
658 bio->bi_next = NULL;
659 }
660
661 return bio;
662}
663
664static inline struct bio *bio_list_get(struct bio_list *bl)
665{
666 struct bio *bio = bl->head;
667
668 bl->head = bl->tail = NULL;
669
670 return bio;
671}
672
57fb233f
KO		 673/*
674 * bio_set is used to allow other portions of the IO system to
675 * allocate their own private memory pools for bio and iovec structures.
676 * These memory pools in turn all allocate from the bio_slab
677 * and the bvec_slabs[].
678 */
679#define BIO_POOL_SIZE 2
680#define BIOVEC_NR_POOLS 6
681#define BIOVEC_MAX_IDX (BIOVEC_NR_POOLS - 1)
682
683struct bio_set {
684 struct kmem_cache *bio_slab;
685 unsigned int front_pad;
686
687 mempool_t *bio_pool;
9f060e22 688 mempool_t *bvec_pool;
57fb233f
KO		 689#if defined(CONFIG_BLK_DEV_INTEGRITY)
690 mempool_t *bio_integrity_pool;
9f060e22 691 mempool_t *bvec_integrity_pool;
57fb233f 692#endif
df2cb6da
KO		 693
694 /*
695 * Deadlock avoidance for stacking block drivers: see comments in
696 * bio_alloc_bioset() for details
697 */
698 spinlock_t rescue_lock;
699 struct bio_list rescue_list;
700 struct work_struct rescue_work;
701 struct workqueue_struct *rescue_workqueue;
57fb233f
KO		 702};
703
704struct biovec_slab {
705 int nr_vecs;
706 char *name;
707 struct kmem_cache *slab;
708};
709
710/*
711 * a small number of entries is fine, not going to be performance critical.
712 * basically we just need to survive
713 */
714#define BIO_SPLIT_ENTRIES 2
715
7ba1ba12
MP		 716#if defined(CONFIG_BLK_DEV_INTEGRITY)
717
d57a5f7c
KO		 718#define bip_for_each_vec(bvl, bip, iter) \
719 for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
7ba1ba12 720
13f05c8d
MP		 721#define bio_for_each_integrity_vec(_bvl, _bio, _iter) \
722 for_each_bio(_bio) \
723 bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
724
7ba1ba12 725extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
1e2a410f 726extern void bio_integrity_free(struct bio *);
7ba1ba12 727extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
e7258c1a 728extern bool bio_integrity_enabled(struct bio *bio);
7ba1ba12 729extern int bio_integrity_prep(struct bio *);
4246a0b6 730extern void bio_integrity_endio(struct bio *);
7ba1ba12
MP		 731extern void bio_integrity_advance(struct bio *, unsigned int);
732extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
1e2a410f 733extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t);
7878cba9
MP		 734extern int bioset_integrity_create(struct bio_set *, int);
735extern void bioset_integrity_free(struct bio_set *);
736extern void bio_integrity_init(void);
7ba1ba12
MP		 737
738#else /* CONFIG_BLK_DEV_INTEGRITY */
739
c611529e 740static inline void *bio_integrity(struct bio *bio)
6898e3bd 741{
c611529e 742 return NULL;
6898e3bd
MP		 743}
744
e7258c1a 745static inline bool bio_integrity_enabled(struct bio *bio)
6898e3bd 746{
e7258c1a 747 return false;
6898e3bd
MP		 748}
749
750static inline int bioset_integrity_create(struct bio_set *bs, int pool_size)
751{
752 return 0;
753}
754
755static inline void bioset_integrity_free (struct bio_set *bs)
756{
757 return;
758}
759
760static inline int bio_integrity_prep(struct bio *bio)
761{
762 return 0;
763}
764
1e2a410f 765static inline void bio_integrity_free(struct bio *bio)
6898e3bd
MP		 766{
767 return;
768}
769
0c614e2d 770static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
1e2a410f 771 gfp_t gfp_mask)
0c614e2d
SR		 772{
773 return 0;
774}
6898e3bd 775
6898e3bd
MP		 776static inline void bio_integrity_advance(struct bio *bio,
777 unsigned int bytes_done)
778{
779 return;
780}
781
782static inline void bio_integrity_trim(struct bio *bio, unsigned int offset,
783 unsigned int sectors)
784{
785 return;
786}
787
788static inline void bio_integrity_init(void)
789{
790 return;
791}
7ba1ba12 792
c611529e
MP		 793static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
794{
795 return false;
796}
797
7ba1ba12
MP		 798#endif /* CONFIG_BLK_DEV_INTEGRITY */
799
02a5e0ac 800#endif /* CONFIG_BLOCK */
1da177e4 801#endif /* __LINUX_BIO_H */
Linux kernel - Deliverables
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