~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/include/linux/bio.h

Version: ~ [ linux-5.15-rc5 ] ~ [ linux-5.14.11 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.72 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.152 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.210 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.250 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.286 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.288 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /* SPDX-License-Identifier: GPL-2.0 */
  2 /*
  3  * Copyright (C) 2001 Jens Axboe <axboe@suse.de>
  4  */
  5 #ifndef __LINUX_BIO_H
  6 #define __LINUX_BIO_H
  7 
  8 #include <linux/highmem.h>
  9 #include <linux/mempool.h>
 10 #include <linux/ioprio.h>
 11 
 12 #ifdef CONFIG_BLOCK
 13 /* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */
 14 #include <linux/blk_types.h>
 15 
 16 #define BIO_DEBUG
 17 
 18 #ifdef BIO_DEBUG
 19 #define BIO_BUG_ON      BUG_ON
 20 #else
 21 #define BIO_BUG_ON
 22 #endif
 23 
 24 #define BIO_MAX_PAGES           256
 25 
 26 #define bio_prio(bio)                   (bio)->bi_ioprio
 27 #define bio_set_prio(bio, prio)         ((bio)->bi_ioprio = prio)
 28 
 29 #define bio_iter_iovec(bio, iter)                               \
 30         bvec_iter_bvec((bio)->bi_io_vec, (iter))
 31 
 32 #define bio_iter_page(bio, iter)                                \
 33         bvec_iter_page((bio)->bi_io_vec, (iter))
 34 #define bio_iter_len(bio, iter)                                 \
 35         bvec_iter_len((bio)->bi_io_vec, (iter))
 36 #define bio_iter_offset(bio, iter)                              \
 37         bvec_iter_offset((bio)->bi_io_vec, (iter))
 38 
 39 #define bio_page(bio)           bio_iter_page((bio), (bio)->bi_iter)
 40 #define bio_offset(bio)         bio_iter_offset((bio), (bio)->bi_iter)
 41 #define bio_iovec(bio)          bio_iter_iovec((bio), (bio)->bi_iter)
 42 
 43 #define bio_multiple_segments(bio)                              \
 44         ((bio)->bi_iter.bi_size != bio_iovec(bio).bv_len)
 45 
 46 #define bvec_iter_sectors(iter) ((iter).bi_size >> 9)
 47 #define bvec_iter_end_sector(iter) ((iter).bi_sector + bvec_iter_sectors((iter)))
 48 
 49 #define bio_sectors(bio)        bvec_iter_sectors((bio)->bi_iter)
 50 #define bio_end_sector(bio)     bvec_iter_end_sector((bio)->bi_iter)
 51 
 52 /*
 53  * Return the data direction, READ or WRITE.
 54  */
 55 #define bio_data_dir(bio) \
 56         (op_is_write(bio_op(bio)) ? WRITE : READ)
 57 
 58 /*
 59  * Check whether this bio carries any data or not. A NULL bio is allowed.
 60  */
 61 static inline bool bio_has_data(struct bio *bio)
 62 {
 63         if (bio &&
 64             bio->bi_iter.bi_size &&
 65             bio_op(bio) != REQ_OP_DISCARD &&
 66             bio_op(bio) != REQ_OP_SECURE_ERASE &&
 67             bio_op(bio) != REQ_OP_WRITE_ZEROES)
 68                 return true;
 69 
 70         return false;
 71 }
 72 
 73 static inline bool bio_no_advance_iter(struct bio *bio)
 74 {
 75         return bio_op(bio) == REQ_OP_DISCARD ||
 76                bio_op(bio) == REQ_OP_SECURE_ERASE ||
 77                bio_op(bio) == REQ_OP_WRITE_SAME ||
 78                bio_op(bio) == REQ_OP_WRITE_ZEROES;
 79 }
 80 
 81 static inline bool bio_mergeable(struct bio *bio)
 82 {
 83         if (bio->bi_opf & REQ_NOMERGE_FLAGS)
 84                 return false;
 85 
 86         return true;
 87 }
 88 
 89 static inline unsigned int bio_cur_bytes(struct bio *bio)
 90 {
 91         if (bio_has_data(bio))
 92                 return bio_iovec(bio).bv_len;
 93         else /* dataless requests such as discard */
 94                 return bio->bi_iter.bi_size;
 95 }
 96 
 97 static inline void *bio_data(struct bio *bio)
 98 {
 99         if (bio_has_data(bio))
100                 return page_address(bio_page(bio)) + bio_offset(bio);
101 
102         return NULL;
103 }
104 
105 /**
106  * bio_full - check if the bio is full
107  * @bio:        bio to check
108  * @len:        length of one segment to be added
109  *
110  * Return true if @bio is full and one segment with @len bytes can't be
111  * added to the bio, otherwise return false
112  */
113 static inline bool bio_full(struct bio *bio, unsigned len)
114 {
115         if (bio->bi_vcnt >= bio->bi_max_vecs)
116                 return true;
117 
118         if (bio->bi_iter.bi_size > UINT_MAX - len)
119                 return true;
120 
121         return false;
122 }
123 
124 static inline bool bio_next_segment(const struct bio *bio,
125                                     struct bvec_iter_all *iter)
126 {
127         if (iter->idx >= bio->bi_vcnt)
128                 return false;
129 
130         bvec_advance(&bio->bi_io_vec[iter->idx], iter);
131         return true;
132 }
133 
134 /*
135  * drivers should _never_ use the all version - the bio may have been split
136  * before it got to the driver and the driver won't own all of it
137  */
138 #define bio_for_each_segment_all(bvl, bio, iter) \
139         for (bvl = bvec_init_iter_all(&iter); bio_next_segment((bio), &iter); )
140 
141 static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter,
142                                     unsigned bytes)
143 {
144         iter->bi_sector += bytes >> 9;
145 
146         if (bio_no_advance_iter(bio))
147                 iter->bi_size -= bytes;
148         else
149                 bvec_iter_advance(bio->bi_io_vec, iter, bytes);
150                 /* TODO: It is reasonable to complete bio with error here. */
151 }
152 
153 #define __bio_for_each_segment(bvl, bio, iter, start)                   \
154         for (iter = (start);                                            \
155              (iter).bi_size &&                                          \
156                 ((bvl = bio_iter_iovec((bio), (iter))), 1);             \
157              bio_advance_iter((bio), &(iter), (bvl).bv_len))
158 
159 #define bio_for_each_segment(bvl, bio, iter)                            \
160         __bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter)
161 
162 #define __bio_for_each_bvec(bvl, bio, iter, start)              \
163         for (iter = (start);                                            \
164              (iter).bi_size &&                                          \
165                 ((bvl = mp_bvec_iter_bvec((bio)->bi_io_vec, (iter))), 1); \
166              bio_advance_iter((bio), &(iter), (bvl).bv_len))
167 
168 /* iterate over multi-page bvec */
169 #define bio_for_each_bvec(bvl, bio, iter)                       \
170         __bio_for_each_bvec(bvl, bio, iter, (bio)->bi_iter)
171 
172 #define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)
173 
174 static inline unsigned bio_segments(struct bio *bio)
175 {
176         unsigned segs = 0;
177         struct bio_vec bv;
178         struct bvec_iter iter;
179 
180         /*
181          * We special case discard/write same/write zeroes, because they
182          * interpret bi_size differently:
183          */
184 
185         switch (bio_op(bio)) {
186         case REQ_OP_DISCARD:
187         case REQ_OP_SECURE_ERASE:
188         case REQ_OP_WRITE_ZEROES:
189                 return 0;
190         case REQ_OP_WRITE_SAME:
191                 return 1;
192         default:
193                 break;
194         }
195 
196         bio_for_each_segment(bv, bio, iter)
197                 segs++;
198 
199         return segs;
200 }
201 
202 /*
203  * get a reference to a bio, so it won't disappear. the intended use is
204  * something like:
205  *
206  * bio_get(bio);
207  * submit_bio(rw, bio);
208  * if (bio->bi_flags ...)
209  *      do_something
210  * bio_put(bio);
211  *
212  * without the bio_get(), it could potentially complete I/O before submit_bio
213  * returns. and then bio would be freed memory when if (bio->bi_flags ...)
214  * runs
215  */
216 static inline void bio_get(struct bio *bio)
217 {
218         bio->bi_flags |= (1 << BIO_REFFED);
219         smp_mb__before_atomic();
220         atomic_inc(&bio->__bi_cnt);
221 }
222 
223 static inline void bio_cnt_set(struct bio *bio, unsigned int count)
224 {
225         if (count != 1) {
226                 bio->bi_flags |= (1 << BIO_REFFED);
227                 smp_mb();
228         }
229         atomic_set(&bio->__bi_cnt, count);
230 }
231 
232 static inline bool bio_flagged(struct bio *bio, unsigned int bit)
233 {
234         return (bio->bi_flags & (1U << bit)) != 0;
235 }
236 
237 static inline void bio_set_flag(struct bio *bio, unsigned int bit)
238 {
239         bio->bi_flags |= (1U << bit);
240 }
241 
242 static inline void bio_clear_flag(struct bio *bio, unsigned int bit)
243 {
244         bio->bi_flags &= ~(1U << bit);
245 }
246 
247 static inline void bio_get_first_bvec(struct bio *bio, struct bio_vec *bv)
248 {
249         *bv = bio_iovec(bio);
250 }
251 
252 static inline void bio_get_last_bvec(struct bio *bio, struct bio_vec *bv)
253 {
254         struct bvec_iter iter = bio->bi_iter;
255         int idx;
256 
257         if (unlikely(!bio_multiple_segments(bio))) {
258                 *bv = bio_iovec(bio);
259                 return;
260         }
261 
262         bio_advance_iter(bio, &iter, iter.bi_size);
263 
264         if (!iter.bi_bvec_done)
265                 idx = iter.bi_idx - 1;
266         else    /* in the middle of bvec */
267                 idx = iter.bi_idx;
268 
269         *bv = bio->bi_io_vec[idx];
270 
271         /*
272          * iter.bi_bvec_done records actual length of the last bvec
273          * if this bio ends in the middle of one io vector
274          */
275         if (iter.bi_bvec_done)
276                 bv->bv_len = iter.bi_bvec_done;
277 }
278 
279 static inline struct bio_vec *bio_first_bvec_all(struct bio *bio)
280 {
281         WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
282         return bio->bi_io_vec;
283 }
284 
285 static inline struct page *bio_first_page_all(struct bio *bio)
286 {
287         return bio_first_bvec_all(bio)->bv_page;
288 }
289 
290 static inline struct bio_vec *bio_last_bvec_all(struct bio *bio)
291 {
292         WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
293         return &bio->bi_io_vec[bio->bi_vcnt - 1];
294 }
295 
296 enum 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 
304 /*
305  * bio integrity payload
306  */
307 struct bio_integrity_payload {
308         struct bio              *bip_bio;       /* parent bio */
309 
310         struct bvec_iter        bip_iter;
311 
312         unsigned short          bip_slab;       /* slab the bip came from */
313         unsigned short          bip_vcnt;       /* # of integrity bio_vecs */
314         unsigned short          bip_max_vcnt;   /* integrity bio_vec slots */
315         unsigned short          bip_flags;      /* control flags */
316 
317         struct bvec_iter        bio_iter;       /* for rewinding parent bio */
318 
319         struct work_struct      bip_work;       /* I/O completion */
320 
321         struct bio_vec          *bip_vec;
322         struct bio_vec          bip_inline_vecs[0];/* embedded bvec array */
323 };
324 
325 #if defined(CONFIG_BLK_DEV_INTEGRITY)
326 
327 static inline struct bio_integrity_payload *bio_integrity(struct bio *bio)
328 {
329         if (bio->bi_opf & REQ_INTEGRITY)
330                 return bio->bi_integrity;
331 
332         return NULL;
333 }
334 
335 static 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 }
344 
345 static inline sector_t bip_get_seed(struct bio_integrity_payload *bip)
346 {
347         return bip->bip_iter.bi_sector;
348 }
349 
350 static inline void bip_set_seed(struct bio_integrity_payload *bip,
351                                 sector_t seed)
352 {
353         bip->bip_iter.bi_sector = seed;
354 }
355 
356 #endif /* CONFIG_BLK_DEV_INTEGRITY */
357 
358 extern void bio_trim(struct bio *bio, int offset, int size);
359 extern 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  */
372 static 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 
381 enum {
382         BIOSET_NEED_BVECS = BIT(0),
383         BIOSET_NEED_RESCUER = BIT(1),
384 };
385 extern int bioset_init(struct bio_set *, unsigned int, unsigned int, int flags);
386 extern void bioset_exit(struct bio_set *);
387 extern int biovec_init_pool(mempool_t *pool, int pool_entries);
388 extern int bioset_init_from_src(struct bio_set *bs, struct bio_set *src);
389 
390 extern struct bio *bio_alloc_bioset(gfp_t, unsigned int, struct bio_set *);
391 extern void bio_put(struct bio *);
392 
393 extern void __bio_clone_fast(struct bio *, struct bio *);
394 extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *);
395 
396 extern struct bio_set fs_bio_set;
397 
398 static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
399 {
400         return bio_alloc_bioset(gfp_mask, nr_iovecs, &fs_bio_set);
401 }
402 
403 static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
404 {
405         return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
406 }
407 
408 extern blk_qc_t submit_bio(struct bio *);
409 
410 extern void bio_endio(struct bio *);
411 
412 static inline void bio_io_error(struct bio *bio)
413 {
414         bio->bi_status = BLK_STS_IOERR;
415         bio_endio(bio);
416 }
417 
418 static inline void bio_wouldblock_error(struct bio *bio)
419 {
420         bio->bi_status = BLK_STS_AGAIN;
421         bio_endio(bio);
422 }
423 
424 struct request_queue;
425 
426 extern int submit_bio_wait(struct bio *bio);
427 extern void bio_advance(struct bio *, unsigned);
428 
429 extern void bio_init(struct bio *bio, struct bio_vec *table,
430                      unsigned short max_vecs);
431 extern void bio_uninit(struct bio *);
432 extern void bio_reset(struct bio *);
433 void bio_chain(struct bio *, struct bio *);
434 
435 extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
436 extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
437                            unsigned int, unsigned int);
438 bool __bio_try_merge_page(struct bio *bio, struct page *page,
439                 unsigned int len, unsigned int off, bool *same_page);
440 void __bio_add_page(struct bio *bio, struct page *page,
441                 unsigned int len, unsigned int off);
442 int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter);
443 void bio_release_pages(struct bio *bio, bool mark_dirty);
444 struct rq_map_data;
445 extern struct bio *bio_map_user_iov(struct request_queue *,
446                                     struct iov_iter *, gfp_t);
447 extern void bio_unmap_user(struct bio *);
448 extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
449                                 gfp_t);
450 extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
451                                  gfp_t, int);
452 extern void bio_set_pages_dirty(struct bio *bio);
453 extern void bio_check_pages_dirty(struct bio *bio);
454 
455 void generic_start_io_acct(struct request_queue *q, int op,
456                                 unsigned long sectors, struct hd_struct *part);
457 void generic_end_io_acct(struct request_queue *q, int op,
458                                 struct hd_struct *part,
459                                 unsigned long start_time);
460 
461 extern void bio_copy_data_iter(struct bio *dst, struct bvec_iter *dst_iter,
462                                struct bio *src, struct bvec_iter *src_iter);
463 extern void bio_copy_data(struct bio *dst, struct bio *src);
464 extern void bio_list_copy_data(struct bio *dst, struct bio *src);
465 extern void bio_free_pages(struct bio *bio);
466 
467 extern struct bio *bio_copy_user_iov(struct request_queue *,
468                                      struct rq_map_data *,
469                                      struct iov_iter *,
470                                      gfp_t);
471 extern int bio_uncopy_user(struct bio *);
472 void zero_fill_bio_iter(struct bio *bio, struct bvec_iter iter);
473 void bio_truncate(struct bio *bio, unsigned new_size);
474 
475 static inline void zero_fill_bio(struct bio *bio)
476 {
477         zero_fill_bio_iter(bio, bio->bi_iter);
478 }
479 
480 extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *);
481 extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int);
482 extern unsigned int bvec_nr_vecs(unsigned short idx);
483 extern const char *bio_devname(struct bio *bio, char *buffer);
484 
485 #define bio_set_dev(bio, bdev)                  \
486 do {                                            \
487         if ((bio)->bi_disk != (bdev)->bd_disk)  \
488                 bio_clear_flag(bio, BIO_THROTTLED);\
489         (bio)->bi_disk = (bdev)->bd_disk;       \
490         (bio)->bi_partno = (bdev)->bd_partno;   \
491         bio_associate_blkg(bio);                \
492 } while (0)
493 
494 #define bio_copy_dev(dst, src)                  \
495 do {                                            \
496         (dst)->bi_disk = (src)->bi_disk;        \
497         (dst)->bi_partno = (src)->bi_partno;    \
498         bio_clone_blkg_association(dst, src);   \
499 } while (0)
500 
501 #define bio_dev(bio) \
502         disk_devt((bio)->bi_disk)
503 
504 #if defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP)
505 void bio_associate_blkg_from_page(struct bio *bio, struct page *page);
506 #else
507 static inline void bio_associate_blkg_from_page(struct bio *bio,
508                                                 struct page *page) { }
509 #endif
510 
511 #ifdef CONFIG_BLK_CGROUP
512 void bio_disassociate_blkg(struct bio *bio);
513 void bio_associate_blkg(struct bio *bio);
514 void bio_associate_blkg_from_css(struct bio *bio,
515                                  struct cgroup_subsys_state *css);
516 void bio_clone_blkg_association(struct bio *dst, struct bio *src);
517 #else   /* CONFIG_BLK_CGROUP */
518 static inline void bio_disassociate_blkg(struct bio *bio) { }
519 static inline void bio_associate_blkg(struct bio *bio) { }
520 static inline void bio_associate_blkg_from_css(struct bio *bio,
521                                                struct cgroup_subsys_state *css)
522 { }
523 static inline void bio_clone_blkg_association(struct bio *dst,
524                                               struct bio *src) { }
525 #endif  /* CONFIG_BLK_CGROUP */
526 
527 #ifdef CONFIG_HIGHMEM
528 /*
529  * remember never ever reenable interrupts between a bvec_kmap_irq and
530  * bvec_kunmap_irq!
531  */
532 static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
533 {
534         unsigned long addr;
535 
536         /*
537          * might not be a highmem page, but the preempt/irq count
538          * balancing is a lot nicer this way
539          */
540         local_irq_save(*flags);
541         addr = (unsigned long) kmap_atomic(bvec->bv_page);
542 
543         BUG_ON(addr & ~PAGE_MASK);
544 
545         return (char *) addr + bvec->bv_offset;
546 }
547 
548 static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
549 {
550         unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
551 
552         kunmap_atomic((void *) ptr);
553         local_irq_restore(*flags);
554 }
555 
556 #else
557 static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
558 {
559         return page_address(bvec->bv_page) + bvec->bv_offset;
560 }
561 
562 static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
563 {
564         *flags = 0;
565 }
566 #endif
567 
568 /*
569  * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
570  *
571  * A bio_list anchors a singly-linked list of bios chained through the bi_next
572  * member of the bio.  The bio_list also caches the last list member to allow
573  * fast access to the tail.
574  */
575 struct bio_list {
576         struct bio *head;
577         struct bio *tail;
578 };
579 
580 static inline int bio_list_empty(const struct bio_list *bl)
581 {
582         return bl->head == NULL;
583 }
584 
585 static inline void bio_list_init(struct bio_list *bl)
586 {
587         bl->head = bl->tail = NULL;
588 }
589 
590 #define BIO_EMPTY_LIST  { NULL, NULL }
591 
592 #define bio_list_for_each(bio, bl) \
593         for (bio = (bl)->head; bio; bio = bio->bi_next)
594 
595 static inline unsigned bio_list_size(const struct bio_list *bl)
596 {
597         unsigned sz = 0;
598         struct bio *bio;
599 
600         bio_list_for_each(bio, bl)
601                 sz++;
602 
603         return sz;
604 }
605 
606 static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
607 {
608         bio->bi_next = NULL;
609 
610         if (bl->tail)
611                 bl->tail->bi_next = bio;
612         else
613                 bl->head = bio;
614 
615         bl->tail = bio;
616 }
617 
618 static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
619 {
620         bio->bi_next = bl->head;
621 
622         bl->head = bio;
623 
624         if (!bl->tail)
625                 bl->tail = bio;
626 }
627 
628 static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
629 {
630         if (!bl2->head)
631                 return;
632 
633         if (bl->tail)
634                 bl->tail->bi_next = bl2->head;
635         else
636                 bl->head = bl2->head;
637 
638         bl->tail = bl2->tail;
639 }
640 
641 static inline void bio_list_merge_head(struct bio_list *bl,
642                                        struct bio_list *bl2)
643 {
644         if (!bl2->head)
645                 return;
646 
647         if (bl->head)
648                 bl2->tail->bi_next = bl->head;
649         else
650                 bl->tail = bl2->tail;
651 
652         bl->head = bl2->head;
653 }
654 
655 static inline struct bio *bio_list_peek(struct bio_list *bl)
656 {
657         return bl->head;
658 }
659 
660 static inline struct bio *bio_list_pop(struct bio_list *bl)
661 {
662         struct bio *bio = bl->head;
663 
664         if (bio) {
665                 bl->head = bl->head->bi_next;
666                 if (!bl->head)
667                         bl->tail = NULL;
668 
669                 bio->bi_next = NULL;
670         }
671 
672         return bio;
673 }
674 
675 static inline struct bio *bio_list_get(struct bio_list *bl)
676 {
677         struct bio *bio = bl->head;
678 
679         bl->head = bl->tail = NULL;
680 
681         return bio;
682 }
683 
684 /*
685  * Increment chain count for the bio. Make sure the CHAIN flag update
686  * is visible before the raised count.
687  */
688 static inline void bio_inc_remaining(struct bio *bio)
689 {
690         bio_set_flag(bio, BIO_CHAIN);
691         smp_mb__before_atomic();
692         atomic_inc(&bio->__bi_remaining);
693 }
694 
695 /*
696  * bio_set is used to allow other portions of the IO system to
697  * allocate their own private memory pools for bio and iovec structures.
698  * These memory pools in turn all allocate from the bio_slab
699  * and the bvec_slabs[].
700  */
701 #define BIO_POOL_SIZE 2
702 
703 struct bio_set {
704         struct kmem_cache *bio_slab;
705         unsigned int front_pad;
706 
707         mempool_t bio_pool;
708         mempool_t bvec_pool;
709 #if defined(CONFIG_BLK_DEV_INTEGRITY)
710         mempool_t bio_integrity_pool;
711         mempool_t bvec_integrity_pool;
712 #endif
713 
714         /*
715          * Deadlock avoidance for stacking block drivers: see comments in
716          * bio_alloc_bioset() for details
717          */
718         spinlock_t              rescue_lock;
719         struct bio_list         rescue_list;
720         struct work_struct      rescue_work;
721         struct workqueue_struct *rescue_workqueue;
722 };
723 
724 struct biovec_slab {
725         int nr_vecs;
726         char *name;
727         struct kmem_cache *slab;
728 };
729 
730 static inline bool bioset_initialized(struct bio_set *bs)
731 {
732         return bs->bio_slab != NULL;
733 }
734 
735 /*
736  * a small number of entries is fine, not going to be performance critical.
737  * basically we just need to survive
738  */
739 #define BIO_SPLIT_ENTRIES 2
740 
741 #if defined(CONFIG_BLK_DEV_INTEGRITY)
742 
743 #define bip_for_each_vec(bvl, bip, iter)                                \
744         for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
745 
746 #define bio_for_each_integrity_vec(_bvl, _bio, _iter)                   \
747         for_each_bio(_bio)                                              \
748                 bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
749 
750 extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
751 extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
752 extern bool bio_integrity_prep(struct bio *);
753 extern void bio_integrity_advance(struct bio *, unsigned int);
754 extern void bio_integrity_trim(struct bio *);
755 extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t);
756 extern int bioset_integrity_create(struct bio_set *, int);
757 extern void bioset_integrity_free(struct bio_set *);
758 extern void bio_integrity_init(void);
759 
760 #else /* CONFIG_BLK_DEV_INTEGRITY */
761 
762 static inline void *bio_integrity(struct bio *bio)
763 {
764         return NULL;
765 }
766 
767 static inline int bioset_integrity_create(struct bio_set *bs, int pool_size)
768 {
769         return 0;
770 }
771 
772 static inline void bioset_integrity_free (struct bio_set *bs)
773 {
774         return;
775 }
776 
777 static inline bool bio_integrity_prep(struct bio *bio)
778 {
779         return true;
780 }
781 
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 
788 static inline void bio_integrity_advance(struct bio *bio,
789                                          unsigned int bytes_done)
790 {
791         return;
792 }
793 
794 static inline void bio_integrity_trim(struct bio *bio)
795 {
796         return;
797 }
798 
799 static inline void bio_integrity_init(void)
800 {
801         return;
802 }
803 
804 static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
805 {
806         return false;
807 }
808 
809 static inline void *bio_integrity_alloc(struct bio * bio, gfp_t gfp,
810                                                                 unsigned int nr)
811 {
812         return ERR_PTR(-EINVAL);
813 }
814 
815 static inline int bio_integrity_add_page(struct bio *bio, struct page *page,
816                                         unsigned int len, unsigned int offset)
817 {
818         return 0;
819 }
820 
821 #endif /* CONFIG_BLK_DEV_INTEGRITY */
822 
823 /*
824  * Mark a bio as polled. Note that for async polled IO, the caller must
825  * expect -EWOULDBLOCK if we cannot allocate a request (or other resources).
826  * We cannot block waiting for requests on polled IO, as those completions
827  * must be found by the caller. This is different than IRQ driven IO, where
828  * it's safe to wait for IO to complete.
829  */
830 static inline void bio_set_polled(struct bio *bio, struct kiocb *kiocb)
831 {
832         bio->bi_opf |= REQ_HIPRI;
833         if (!is_sync_kiocb(kiocb))
834                 bio->bi_opf |= REQ_NOWAIT;
835 }
836 
837 #endif /* CONFIG_BLOCK */
838 #endif /* __LINUX_BIO_H */
839 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp