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