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
12 *
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>
25 #include <linux/ioprio.h>
26 #include <linux/bug.h>
27
28 #ifdef CONFIG_BLOCK
29
30 #include <asm/io.h>
31
32 /* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */
33 #include <linux/blk_types.h>
34
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
43 #define BIO_MAX_PAGES 256
44 #define BIO_MAX_SIZE (BIO_MAX_PAGES << PAGE_CACHE_SHIFT)
45 #define BIO_MAX_SECTORS (BIO_MAX_SIZE >> 9)
46
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
60 /*
61 * various member access, note that bio_data should of course not be used
62 * on highmem page vectors
63 */
64 #define __bvec_iter_bvec(bvec, iter) (&(bvec)[(iter).bi_idx])
65
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)
96
97 #define bio_multiple_segments(bio) \
98 ((bio)->bi_iter.bi_size != bio_iovec(bio).bv_len)
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)))
101
102 /*
103 * Check whether this bio carries any data or not. A NULL bio is allowed.
104 */
bio_has_data(struct bio * bio)105 static 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
bio_is_rw(struct bio * bio)115 static 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
bio_mergeable(struct bio * bio)126 static 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
bio_cur_bytes(struct bio * bio)134 static inline unsigned int bio_cur_bytes(struct bio *bio)
135 {
136 if (bio_has_data(bio))
137 return bio_iovec(bio).bv_len;
138 else /* dataless requests such as discard */
139 return bio->bi_iter.bi_size;
140 }
141
bio_data(struct bio * bio)142 static inline void *bio_data(struct bio *bio)
143 {
144 if (bio_has_data(bio))
145 return page_address(bio_page(bio)) + bio_offset(bio);
146
147 return NULL;
148 }
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 */
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)
165
166 #define __bio_kunmap_atomic(addr) kunmap_atomic(addr)
167
168 /*
169 * merge helpers etc
170 */
171
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
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) \
181 __BIOVEC_PHYS_MERGEABLE(vec1, vec2)
182 #endif
183
184 #define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
185 (((addr1) | (mask)) == (((addr2) - 1) | (mask)))
186 #define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
187 __BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q)))
188
189 /*
190 * Check if adding a bio_vec after bprv with offset would create a gap in
191 * the SG list. Most drivers don't care about this, but some do.
192 */
bvec_gap_to_prev(struct bio_vec * bprv,unsigned int offset)193 static inline bool bvec_gap_to_prev(struct bio_vec *bprv, unsigned int offset)
194 {
195 return offset || ((bprv->bv_offset + bprv->bv_len) & (PAGE_SIZE - 1));
196 }
197
198 #define bio_io_error(bio) bio_endio((bio), -EIO)
199
200 /*
201 * drivers should _never_ use the all version - the bio may have been split
202 * before it got to the driver and the driver won't own all of it
203 */
204 #define bio_for_each_segment_all(bvl, bio, i) \
205 for (i = 0, bvl = (bio)->bi_io_vec; i < (bio)->bi_vcnt; i++, bvl++)
206
bvec_iter_advance(struct bio_vec * bv,struct bvec_iter * iter,unsigned bytes)207 static inline void bvec_iter_advance(struct bio_vec *bv, struct bvec_iter *iter,
208 unsigned bytes)
209 {
210 WARN_ONCE(bytes > iter->bi_size,
211 "Attempted to advance past end of bvec iter\n");
212
213 while (bytes) {
214 unsigned len = min(bytes, bvec_iter_len(bv, *iter));
215
216 bytes -= len;
217 iter->bi_size -= len;
218 iter->bi_bvec_done += len;
219
220 if (iter->bi_bvec_done == __bvec_iter_bvec(bv, *iter)->bv_len) {
221 iter->bi_bvec_done = 0;
222 iter->bi_idx++;
223 }
224 }
225 }
226
227 #define for_each_bvec(bvl, bio_vec, iter, start) \
228 for (iter = (start); \
229 (iter).bi_size && \
230 ((bvl = bvec_iter_bvec((bio_vec), (iter))), 1); \
231 bvec_iter_advance((bio_vec), &(iter), (bvl).bv_len))
232
233
bio_advance_iter(struct bio * bio,struct bvec_iter * iter,unsigned bytes)234 static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter,
235 unsigned bytes)
236 {
237 iter->bi_sector += bytes >> 9;
238
239 if (bio->bi_rw & BIO_NO_ADVANCE_ITER_MASK)
240 iter->bi_size -= bytes;
241 else
242 bvec_iter_advance(bio->bi_io_vec, iter, bytes);
243 }
244
245 #define __bio_for_each_segment(bvl, bio, iter, start) \
246 for (iter = (start); \
247 (iter).bi_size && \
248 ((bvl = bio_iter_iovec((bio), (iter))), 1); \
249 bio_advance_iter((bio), &(iter), (bvl).bv_len))
250
251 #define bio_for_each_segment(bvl, bio, iter) \
252 __bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter)
253
254 #define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)
255
bio_segments(struct bio * bio)256 static inline unsigned bio_segments(struct bio *bio)
257 {
258 unsigned segs = 0;
259 struct bio_vec bv;
260 struct bvec_iter iter;
261
262 /*
263 * We special case discard/write same, because they interpret bi_size
264 * differently:
265 */
266
267 if (bio->bi_rw & REQ_DISCARD)
268 return 1;
269
270 if (bio->bi_rw & REQ_WRITE_SAME)
271 return 1;
272
273 bio_for_each_segment(bv, bio, iter)
274 segs++;
275
276 return segs;
277 }
278
279 /*
280 * get a reference to a bio, so it won't disappear. the intended use is
281 * something like:
282 *
283 * bio_get(bio);
284 * submit_bio(rw, bio);
285 * if (bio->bi_flags ...)
286 * do_something
287 * bio_put(bio);
288 *
289 * without the bio_get(), it could potentially complete I/O before submit_bio
290 * returns. and then bio would be freed memory when if (bio->bi_flags ...)
291 * runs
292 */
293 #define bio_get(bio) atomic_inc(&(bio)->bi_cnt)
294
bio_get_first_bvec(struct bio * bio,struct bio_vec * bv)295 static inline void bio_get_first_bvec(struct bio *bio, struct bio_vec *bv)
296 {
297 *bv = bio_iovec(bio);
298 }
299
bio_get_last_bvec(struct bio * bio,struct bio_vec * bv)300 static inline void bio_get_last_bvec(struct bio *bio, struct bio_vec *bv)
301 {
302 struct bvec_iter iter = bio->bi_iter;
303 int idx;
304
305 if (!bio_flagged(bio, BIO_CLONED)) {
306 *bv = bio->bi_io_vec[bio->bi_vcnt - 1];
307 return;
308 }
309
310 if (unlikely(!bio_multiple_segments(bio))) {
311 *bv = bio_iovec(bio);
312 return;
313 }
314
315 bio_advance_iter(bio, &iter, iter.bi_size);
316
317 if (!iter.bi_bvec_done)
318 idx = iter.bi_idx - 1;
319 else /* in the middle of bvec */
320 idx = iter.bi_idx;
321
322 *bv = bio->bi_io_vec[idx];
323
324 /*
325 * iter.bi_bvec_done records actual length of the last bvec
326 * if this bio ends in the middle of one io vector
327 */
328 if (iter.bi_bvec_done)
329 bv->bv_len = iter.bi_bvec_done;
330 }
331
332 enum bip_flags {
333 BIP_BLOCK_INTEGRITY = 1 << 0, /* block layer owns integrity data */
334 BIP_MAPPED_INTEGRITY = 1 << 1, /* ref tag has been remapped */
335 BIP_CTRL_NOCHECK = 1 << 2, /* disable HBA integrity checking */
336 BIP_DISK_NOCHECK = 1 << 3, /* disable disk integrity checking */
337 BIP_IP_CHECKSUM = 1 << 4, /* IP checksum */
338 };
339
340 #if defined(CONFIG_BLK_DEV_INTEGRITY)
341
bio_integrity(struct bio * bio)342 static inline struct bio_integrity_payload *bio_integrity(struct bio *bio)
343 {
344 if (bio->bi_rw & REQ_INTEGRITY)
345 return bio->bi_integrity;
346
347 return NULL;
348 }
349
350 /*
351 * bio integrity payload
352 */
353 struct bio_integrity_payload {
354 struct bio *bip_bio; /* parent bio */
355
356 struct bvec_iter bip_iter;
357
358 bio_end_io_t *bip_end_io; /* saved I/O completion fn */
359
360 unsigned short bip_slab; /* slab the bip came from */
361 unsigned short bip_vcnt; /* # of integrity bio_vecs */
362 unsigned short bip_max_vcnt; /* integrity bio_vec slots */
363 unsigned short bip_flags; /* control flags */
364
365 struct work_struct bip_work; /* I/O completion */
366
367 struct bio_vec *bip_vec;
368 struct bio_vec bip_inline_vecs[0];/* embedded bvec array */
369 };
370
bio_integrity_flagged(struct bio * bio,enum bip_flags flag)371 static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
372 {
373 struct bio_integrity_payload *bip = bio_integrity(bio);
374
375 if (bip)
376 return bip->bip_flags & flag;
377
378 return false;
379 }
380
bip_get_seed(struct bio_integrity_payload * bip)381 static inline sector_t bip_get_seed(struct bio_integrity_payload *bip)
382 {
383 return bip->bip_iter.bi_sector;
384 }
385
bip_set_seed(struct bio_integrity_payload * bip,sector_t seed)386 static inline void bip_set_seed(struct bio_integrity_payload *bip,
387 sector_t seed)
388 {
389 bip->bip_iter.bi_sector = seed;
390 }
391
392 #endif /* CONFIG_BLK_DEV_INTEGRITY */
393
394 extern void bio_trim(struct bio *bio, int offset, int size);
395 extern struct bio *bio_split(struct bio *bio, int sectors,
396 gfp_t gfp, struct bio_set *bs);
397
398 /**
399 * bio_next_split - get next @sectors from a bio, splitting if necessary
400 * @bio: bio to split
401 * @sectors: number of sectors to split from the front of @bio
402 * @gfp: gfp mask
403 * @bs: bio set to allocate from
404 *
405 * Returns a bio representing the next @sectors of @bio - if the bio is smaller
406 * than @sectors, returns the original bio unchanged.
407 */
bio_next_split(struct bio * bio,int sectors,gfp_t gfp,struct bio_set * bs)408 static inline struct bio *bio_next_split(struct bio *bio, int sectors,
409 gfp_t gfp, struct bio_set *bs)
410 {
411 if (sectors >= bio_sectors(bio))
412 return bio;
413
414 return bio_split(bio, sectors, gfp, bs);
415 }
416
417 extern struct bio_set *bioset_create(unsigned int, unsigned int);
418 extern struct bio_set *bioset_create_nobvec(unsigned int, unsigned int);
419 extern void bioset_free(struct bio_set *);
420 extern mempool_t *biovec_create_pool(int pool_entries);
421
422 extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
423 extern void bio_put(struct bio *);
424
425 extern void __bio_clone_fast(struct bio *, struct bio *);
426 extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *);
427 extern struct bio *bio_clone_bioset(struct bio *, gfp_t, struct bio_set *bs);
428
429 extern struct bio_set *fs_bio_set;
430
bio_alloc(gfp_t gfp_mask,unsigned int nr_iovecs)431 static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
432 {
433 return bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set);
434 }
435
bio_clone(struct bio * bio,gfp_t gfp_mask)436 static inline struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask)
437 {
438 return bio_clone_bioset(bio, gfp_mask, fs_bio_set);
439 }
440
bio_kmalloc(gfp_t gfp_mask,unsigned int nr_iovecs)441 static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
442 {
443 return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
444 }
445
bio_clone_kmalloc(struct bio * bio,gfp_t gfp_mask)446 static inline struct bio *bio_clone_kmalloc(struct bio *bio, gfp_t gfp_mask)
447 {
448 return bio_clone_bioset(bio, gfp_mask, NULL);
449
450 }
451
452 extern void bio_endio(struct bio *, int);
453 extern void bio_endio_nodec(struct bio *, int);
454 struct request_queue;
455 extern int bio_phys_segments(struct request_queue *, struct bio *);
456
457 extern int submit_bio_wait(int rw, struct bio *bio);
458 extern void bio_advance(struct bio *, unsigned);
459
460 extern void bio_init(struct bio *);
461 extern void bio_reset(struct bio *);
462 void bio_chain(struct bio *, struct bio *);
463
464 extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
465 extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
466 unsigned int, unsigned int);
467 extern int bio_get_nr_vecs(struct block_device *);
468 extern struct bio *bio_map_user(struct request_queue *, struct block_device *,
469 unsigned long, unsigned int, int, gfp_t);
470 struct sg_iovec;
471 struct rq_map_data;
472 extern struct bio *bio_map_user_iov(struct request_queue *,
473 struct block_device *,
474 const struct sg_iovec *, int, int, gfp_t);
475 extern void bio_unmap_user(struct bio *);
476 extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
477 gfp_t);
478 extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
479 gfp_t, int);
480 extern void bio_set_pages_dirty(struct bio *bio);
481 extern void bio_check_pages_dirty(struct bio *bio);
482
483 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
484 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
485 #endif
486 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
487 extern void bio_flush_dcache_pages(struct bio *bi);
488 #else
bio_flush_dcache_pages(struct bio * bi)489 static inline void bio_flush_dcache_pages(struct bio *bi)
490 {
491 }
492 #endif
493
494 extern void bio_copy_data(struct bio *dst, struct bio *src);
495 extern int bio_alloc_pages(struct bio *bio, gfp_t gfp);
496
497 extern struct bio *bio_copy_user(struct request_queue *, struct rq_map_data *,
498 unsigned long, unsigned int, int, gfp_t);
499 extern struct bio *bio_copy_user_iov(struct request_queue *,
500 struct rq_map_data *,
501 const struct sg_iovec *,
502 int, int, gfp_t);
503 extern int bio_uncopy_user(struct bio *);
504 void zero_fill_bio(struct bio *bio);
505 extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *);
506 extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int);
507 extern unsigned int bvec_nr_vecs(unsigned short idx);
508
509 #ifdef CONFIG_BLK_CGROUP
510 int bio_associate_current(struct bio *bio);
511 void bio_disassociate_task(struct bio *bio);
512 #else /* CONFIG_BLK_CGROUP */
bio_associate_current(struct bio * bio)513 static inline int bio_associate_current(struct bio *bio) { return -ENOENT; }
bio_disassociate_task(struct bio * bio)514 static inline void bio_disassociate_task(struct bio *bio) { }
515 #endif /* CONFIG_BLK_CGROUP */
516
517 #ifdef CONFIG_HIGHMEM
518 /*
519 * remember never ever reenable interrupts between a bvec_kmap_irq and
520 * bvec_kunmap_irq!
521 */
bvec_kmap_irq(struct bio_vec * bvec,unsigned long * flags)522 static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
523 {
524 unsigned long addr;
525
526 /*
527 * might not be a highmem page, but the preempt/irq count
528 * balancing is a lot nicer this way
529 */
530 local_irq_save(*flags);
531 addr = (unsigned long) kmap_atomic(bvec->bv_page);
532
533 BUG_ON(addr & ~PAGE_MASK);
534
535 return (char *) addr + bvec->bv_offset;
536 }
537
bvec_kunmap_irq(char * buffer,unsigned long * flags)538 static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
539 {
540 unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
541
542 kunmap_atomic((void *) ptr);
543 local_irq_restore(*flags);
544 }
545
546 #else
bvec_kmap_irq(struct bio_vec * bvec,unsigned long * flags)547 static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
548 {
549 return page_address(bvec->bv_page) + bvec->bv_offset;
550 }
551
bvec_kunmap_irq(char * buffer,unsigned long * flags)552 static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
553 {
554 *flags = 0;
555 }
556 #endif
557
__bio_kmap_irq(struct bio * bio,struct bvec_iter iter,unsigned long * flags)558 static inline char *__bio_kmap_irq(struct bio *bio, struct bvec_iter iter,
559 unsigned long *flags)
560 {
561 return bvec_kmap_irq(&bio_iter_iovec(bio, iter), flags);
562 }
563 #define __bio_kunmap_irq(buf, flags) bvec_kunmap_irq(buf, flags)
564
565 #define bio_kmap_irq(bio, flags) \
566 __bio_kmap_irq((bio), (bio)->bi_iter, (flags))
567 #define bio_kunmap_irq(buf,flags) __bio_kunmap_irq(buf, flags)
568
569 /*
570 * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
571 *
572 * A bio_list anchors a singly-linked list of bios chained through the bi_next
573 * member of the bio. The bio_list also caches the last list member to allow
574 * fast access to the tail.
575 */
576 struct bio_list {
577 struct bio *head;
578 struct bio *tail;
579 };
580
bio_list_empty(const struct bio_list * bl)581 static inline int bio_list_empty(const struct bio_list *bl)
582 {
583 return bl->head == NULL;
584 }
585
bio_list_init(struct bio_list * bl)586 static inline void bio_list_init(struct bio_list *bl)
587 {
588 bl->head = bl->tail = NULL;
589 }
590
591 #define BIO_EMPTY_LIST { NULL, NULL }
592
593 #define bio_list_for_each(bio, bl) \
594 for (bio = (bl)->head; bio; bio = bio->bi_next)
595
bio_list_size(const struct bio_list * bl)596 static inline unsigned bio_list_size(const struct bio_list *bl)
597 {
598 unsigned sz = 0;
599 struct bio *bio;
600
601 bio_list_for_each(bio, bl)
602 sz++;
603
604 return sz;
605 }
606
bio_list_add(struct bio_list * bl,struct bio * bio)607 static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
608 {
609 bio->bi_next = NULL;
610
611 if (bl->tail)
612 bl->tail->bi_next = bio;
613 else
614 bl->head = bio;
615
616 bl->tail = bio;
617 }
618
bio_list_add_head(struct bio_list * bl,struct bio * bio)619 static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
620 {
621 bio->bi_next = bl->head;
622
623 bl->head = bio;
624
625 if (!bl->tail)
626 bl->tail = bio;
627 }
628
bio_list_merge(struct bio_list * bl,struct bio_list * bl2)629 static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
630 {
631 if (!bl2->head)
632 return;
633
634 if (bl->tail)
635 bl->tail->bi_next = bl2->head;
636 else
637 bl->head = bl2->head;
638
639 bl->tail = bl2->tail;
640 }
641
bio_list_merge_head(struct bio_list * bl,struct bio_list * bl2)642 static inline void bio_list_merge_head(struct bio_list *bl,
643 struct bio_list *bl2)
644 {
645 if (!bl2->head)
646 return;
647
648 if (bl->head)
649 bl2->tail->bi_next = bl->head;
650 else
651 bl->tail = bl2->tail;
652
653 bl->head = bl2->head;
654 }
655
bio_list_peek(struct bio_list * bl)656 static inline struct bio *bio_list_peek(struct bio_list *bl)
657 {
658 return bl->head;
659 }
660
bio_list_pop(struct bio_list * bl)661 static inline struct bio *bio_list_pop(struct bio_list *bl)
662 {
663 struct bio *bio = bl->head;
664
665 if (bio) {
666 bl->head = bl->head->bi_next;
667 if (!bl->head)
668 bl->tail = NULL;
669
670 bio->bi_next = NULL;
671 }
672
673 return bio;
674 }
675
bio_list_get(struct bio_list * bl)676 static inline struct bio *bio_list_get(struct bio_list *bl)
677 {
678 struct bio *bio = bl->head;
679
680 bl->head = bl->tail = NULL;
681
682 return bio;
683 }
684
685 /*
686 * bio_set is used to allow other portions of the IO system to
687 * allocate their own private memory pools for bio and iovec structures.
688 * These memory pools in turn all allocate from the bio_slab
689 * and the bvec_slabs[].
690 */
691 #define BIO_POOL_SIZE 2
692 #define BIOVEC_NR_POOLS 6
693 #define BIOVEC_MAX_IDX (BIOVEC_NR_POOLS - 1)
694
695 struct bio_set {
696 struct kmem_cache *bio_slab;
697 unsigned int front_pad;
698
699 mempool_t *bio_pool;
700 mempool_t *bvec_pool;
701 #if defined(CONFIG_BLK_DEV_INTEGRITY)
702 mempool_t *bio_integrity_pool;
703 mempool_t *bvec_integrity_pool;
704 #endif
705
706 /*
707 * Deadlock avoidance for stacking block drivers: see comments in
708 * bio_alloc_bioset() for details
709 */
710 spinlock_t rescue_lock;
711 struct bio_list rescue_list;
712 struct work_struct rescue_work;
713 struct workqueue_struct *rescue_workqueue;
714 };
715
716 struct biovec_slab {
717 int nr_vecs;
718 char *name;
719 struct kmem_cache *slab;
720 };
721
722 /*
723 * a small number of entries is fine, not going to be performance critical.
724 * basically we just need to survive
725 */
726 #define BIO_SPLIT_ENTRIES 2
727
728 #if defined(CONFIG_BLK_DEV_INTEGRITY)
729
730 #define bip_for_each_vec(bvl, bip, iter) \
731 for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
732
733 #define bio_for_each_integrity_vec(_bvl, _bio, _iter) \
734 for_each_bio(_bio) \
735 bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
736
737 extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
738 extern void bio_integrity_free(struct bio *);
739 extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
740 extern bool bio_integrity_enabled(struct bio *bio);
741 extern int bio_integrity_prep(struct bio *);
742 extern void bio_integrity_endio(struct bio *, int);
743 extern void bio_integrity_advance(struct bio *, unsigned int);
744 extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
745 extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t);
746 extern int bioset_integrity_create(struct bio_set *, int);
747 extern void bioset_integrity_free(struct bio_set *);
748 extern void bio_integrity_init(void);
749
750 #else /* CONFIG_BLK_DEV_INTEGRITY */
751
bio_integrity(struct bio * bio)752 static inline void *bio_integrity(struct bio *bio)
753 {
754 return NULL;
755 }
756
bio_integrity_enabled(struct bio * bio)757 static inline bool bio_integrity_enabled(struct bio *bio)
758 {
759 return false;
760 }
761
bioset_integrity_create(struct bio_set * bs,int pool_size)762 static inline int bioset_integrity_create(struct bio_set *bs, int pool_size)
763 {
764 return 0;
765 }
766
bioset_integrity_free(struct bio_set * bs)767 static inline void bioset_integrity_free (struct bio_set *bs)
768 {
769 return;
770 }
771
bio_integrity_prep(struct bio * bio)772 static inline int bio_integrity_prep(struct bio *bio)
773 {
774 return 0;
775 }
776
bio_integrity_free(struct bio * bio)777 static inline void bio_integrity_free(struct bio *bio)
778 {
779 return;
780 }
781
bio_integrity_clone(struct bio * bio,struct bio * bio_src,gfp_t gfp_mask)782 static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
783 gfp_t gfp_mask)
784 {
785 return 0;
786 }
787
bio_integrity_advance(struct bio * bio,unsigned int bytes_done)788 static inline void bio_integrity_advance(struct bio *bio,
789 unsigned int bytes_done)
790 {
791 return;
792 }
793
bio_integrity_trim(struct bio * bio,unsigned int offset,unsigned int sectors)794 static inline void bio_integrity_trim(struct bio *bio, unsigned int offset,
795 unsigned int sectors)
796 {
797 return;
798 }
799
bio_integrity_init(void)800 static inline void bio_integrity_init(void)
801 {
802 return;
803 }
804
bio_integrity_flagged(struct bio * bio,enum bip_flags flag)805 static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
806 {
807 return false;
808 }
809
810 #endif /* CONFIG_BLK_DEV_INTEGRITY */
811
812 #endif /* CONFIG_BLOCK */
813 #endif /* __LINUX_BIO_H */
814