bio.h 20 KB

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  1. /* SPDX-License-Identifier: GPL-2.0 */
  2. /*
  3. * Copyright (C) 2001 Jens Axboe <[email protected]>
  4. */
  5. #ifndef __LINUX_BIO_H
  6. #define __LINUX_BIO_H
  7. #include <linux/mempool.h>
  8. /* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */
  9. #include <linux/blk_types.h>
  10. #include <linux/uio.h>
  11. #define BIO_MAX_VECS 256U
  12. static inline unsigned int bio_max_segs(unsigned int nr_segs)
  13. {
  14. return min(nr_segs, BIO_MAX_VECS);
  15. }
  16. #define bio_prio(bio) (bio)->bi_ioprio
  17. #define bio_set_prio(bio, prio) ((bio)->bi_ioprio = prio)
  18. #define bio_iter_iovec(bio, iter) \
  19. bvec_iter_bvec((bio)->bi_io_vec, (iter))
  20. #define bio_iter_page(bio, iter) \
  21. bvec_iter_page((bio)->bi_io_vec, (iter))
  22. #define bio_iter_len(bio, iter) \
  23. bvec_iter_len((bio)->bi_io_vec, (iter))
  24. #define bio_iter_offset(bio, iter) \
  25. bvec_iter_offset((bio)->bi_io_vec, (iter))
  26. #define bio_page(bio) bio_iter_page((bio), (bio)->bi_iter)
  27. #define bio_offset(bio) bio_iter_offset((bio), (bio)->bi_iter)
  28. #define bio_iovec(bio) bio_iter_iovec((bio), (bio)->bi_iter)
  29. #define bvec_iter_sectors(iter) ((iter).bi_size >> 9)
  30. #define bvec_iter_end_sector(iter) ((iter).bi_sector + bvec_iter_sectors((iter)))
  31. #define bio_sectors(bio) bvec_iter_sectors((bio)->bi_iter)
  32. #define bio_end_sector(bio) bvec_iter_end_sector((bio)->bi_iter)
  33. /*
  34. * Return the data direction, READ or WRITE.
  35. */
  36. #define bio_data_dir(bio) \
  37. (op_is_write(bio_op(bio)) ? WRITE : READ)
  38. /*
  39. * Check whether this bio carries any data or not. A NULL bio is allowed.
  40. */
  41. static inline bool bio_has_data(struct bio *bio)
  42. {
  43. if (bio &&
  44. bio->bi_iter.bi_size &&
  45. bio_op(bio) != REQ_OP_DISCARD &&
  46. bio_op(bio) != REQ_OP_SECURE_ERASE &&
  47. bio_op(bio) != REQ_OP_WRITE_ZEROES)
  48. return true;
  49. return false;
  50. }
  51. static inline bool bio_no_advance_iter(const struct bio *bio)
  52. {
  53. return bio_op(bio) == REQ_OP_DISCARD ||
  54. bio_op(bio) == REQ_OP_SECURE_ERASE ||
  55. bio_op(bio) == REQ_OP_WRITE_ZEROES;
  56. }
  57. static inline void *bio_data(struct bio *bio)
  58. {
  59. if (bio_has_data(bio))
  60. return page_address(bio_page(bio)) + bio_offset(bio);
  61. return NULL;
  62. }
  63. static inline bool bio_next_segment(const struct bio *bio,
  64. struct bvec_iter_all *iter)
  65. {
  66. if (iter->idx >= bio->bi_vcnt)
  67. return false;
  68. bvec_advance(&bio->bi_io_vec[iter->idx], iter);
  69. return true;
  70. }
  71. /*
  72. * drivers should _never_ use the all version - the bio may have been split
  73. * before it got to the driver and the driver won't own all of it
  74. */
  75. #define bio_for_each_segment_all(bvl, bio, iter) \
  76. for (bvl = bvec_init_iter_all(&iter); bio_next_segment((bio), &iter); )
  77. static inline void bio_advance_iter(const struct bio *bio,
  78. struct bvec_iter *iter, unsigned int bytes)
  79. {
  80. iter->bi_sector += bytes >> 9;
  81. if (bio_no_advance_iter(bio))
  82. iter->bi_size -= bytes;
  83. else
  84. bvec_iter_advance(bio->bi_io_vec, iter, bytes);
  85. /* TODO: It is reasonable to complete bio with error here. */
  86. }
  87. /* @bytes should be less or equal to bvec[i->bi_idx].bv_len */
  88. static inline void bio_advance_iter_single(const struct bio *bio,
  89. struct bvec_iter *iter,
  90. unsigned int bytes)
  91. {
  92. iter->bi_sector += bytes >> 9;
  93. if (bio_no_advance_iter(bio))
  94. iter->bi_size -= bytes;
  95. else
  96. bvec_iter_advance_single(bio->bi_io_vec, iter, bytes);
  97. }
  98. void __bio_advance(struct bio *, unsigned bytes);
  99. /**
  100. * bio_advance - increment/complete a bio by some number of bytes
  101. * @bio: bio to advance
  102. * @nbytes: number of bytes to complete
  103. *
  104. * This updates bi_sector, bi_size and bi_idx; if the number of bytes to
  105. * complete doesn't align with a bvec boundary, then bv_len and bv_offset will
  106. * be updated on the last bvec as well.
  107. *
  108. * @bio will then represent the remaining, uncompleted portion of the io.
  109. */
  110. static inline void bio_advance(struct bio *bio, unsigned int nbytes)
  111. {
  112. if (nbytes == bio->bi_iter.bi_size) {
  113. bio->bi_iter.bi_size = 0;
  114. return;
  115. }
  116. __bio_advance(bio, nbytes);
  117. }
  118. #define __bio_for_each_segment(bvl, bio, iter, start) \
  119. for (iter = (start); \
  120. (iter).bi_size && \
  121. ((bvl = bio_iter_iovec((bio), (iter))), 1); \
  122. bio_advance_iter_single((bio), &(iter), (bvl).bv_len))
  123. #define bio_for_each_segment(bvl, bio, iter) \
  124. __bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter)
  125. #define __bio_for_each_bvec(bvl, bio, iter, start) \
  126. for (iter = (start); \
  127. (iter).bi_size && \
  128. ((bvl = mp_bvec_iter_bvec((bio)->bi_io_vec, (iter))), 1); \
  129. bio_advance_iter_single((bio), &(iter), (bvl).bv_len))
  130. /* iterate over multi-page bvec */
  131. #define bio_for_each_bvec(bvl, bio, iter) \
  132. __bio_for_each_bvec(bvl, bio, iter, (bio)->bi_iter)
  133. /*
  134. * Iterate over all multi-page bvecs. Drivers shouldn't use this version for the
  135. * same reasons as bio_for_each_segment_all().
  136. */
  137. #define bio_for_each_bvec_all(bvl, bio, i) \
  138. for (i = 0, bvl = bio_first_bvec_all(bio); \
  139. i < (bio)->bi_vcnt; i++, bvl++)
  140. #define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)
  141. static inline unsigned bio_segments(struct bio *bio)
  142. {
  143. unsigned segs = 0;
  144. struct bio_vec bv;
  145. struct bvec_iter iter;
  146. /*
  147. * We special case discard/write same/write zeroes, because they
  148. * interpret bi_size differently:
  149. */
  150. switch (bio_op(bio)) {
  151. case REQ_OP_DISCARD:
  152. case REQ_OP_SECURE_ERASE:
  153. case REQ_OP_WRITE_ZEROES:
  154. return 0;
  155. default:
  156. break;
  157. }
  158. bio_for_each_segment(bv, bio, iter)
  159. segs++;
  160. return segs;
  161. }
  162. /*
  163. * get a reference to a bio, so it won't disappear. the intended use is
  164. * something like:
  165. *
  166. * bio_get(bio);
  167. * submit_bio(rw, bio);
  168. * if (bio->bi_flags ...)
  169. * do_something
  170. * bio_put(bio);
  171. *
  172. * without the bio_get(), it could potentially complete I/O before submit_bio
  173. * returns. and then bio would be freed memory when if (bio->bi_flags ...)
  174. * runs
  175. */
  176. static inline void bio_get(struct bio *bio)
  177. {
  178. bio->bi_flags |= (1 << BIO_REFFED);
  179. smp_mb__before_atomic();
  180. atomic_inc(&bio->__bi_cnt);
  181. }
  182. static inline void bio_cnt_set(struct bio *bio, unsigned int count)
  183. {
  184. if (count != 1) {
  185. bio->bi_flags |= (1 << BIO_REFFED);
  186. smp_mb();
  187. }
  188. atomic_set(&bio->__bi_cnt, count);
  189. }
  190. static inline bool bio_flagged(struct bio *bio, unsigned int bit)
  191. {
  192. return (bio->bi_flags & (1U << bit)) != 0;
  193. }
  194. static inline void bio_set_flag(struct bio *bio, unsigned int bit)
  195. {
  196. bio->bi_flags |= (1U << bit);
  197. }
  198. static inline void bio_clear_flag(struct bio *bio, unsigned int bit)
  199. {
  200. bio->bi_flags &= ~(1U << bit);
  201. }
  202. static inline struct bio_vec *bio_first_bvec_all(struct bio *bio)
  203. {
  204. WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
  205. return bio->bi_io_vec;
  206. }
  207. static inline struct page *bio_first_page_all(struct bio *bio)
  208. {
  209. return bio_first_bvec_all(bio)->bv_page;
  210. }
  211. static inline struct bio_vec *bio_last_bvec_all(struct bio *bio)
  212. {
  213. WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
  214. return &bio->bi_io_vec[bio->bi_vcnt - 1];
  215. }
  216. /**
  217. * struct folio_iter - State for iterating all folios in a bio.
  218. * @folio: The current folio we're iterating. NULL after the last folio.
  219. * @offset: The byte offset within the current folio.
  220. * @length: The number of bytes in this iteration (will not cross folio
  221. * boundary).
  222. */
  223. struct folio_iter {
  224. struct folio *folio;
  225. size_t offset;
  226. size_t length;
  227. /* private: for use by the iterator */
  228. struct folio *_next;
  229. size_t _seg_count;
  230. int _i;
  231. };
  232. static inline void bio_first_folio(struct folio_iter *fi, struct bio *bio,
  233. int i)
  234. {
  235. struct bio_vec *bvec = bio_first_bvec_all(bio) + i;
  236. fi->folio = page_folio(bvec->bv_page);
  237. fi->offset = bvec->bv_offset +
  238. PAGE_SIZE * (bvec->bv_page - &fi->folio->page);
  239. fi->_seg_count = bvec->bv_len;
  240. fi->length = min(folio_size(fi->folio) - fi->offset, fi->_seg_count);
  241. fi->_next = folio_next(fi->folio);
  242. fi->_i = i;
  243. }
  244. static inline void bio_next_folio(struct folio_iter *fi, struct bio *bio)
  245. {
  246. fi->_seg_count -= fi->length;
  247. if (fi->_seg_count) {
  248. fi->folio = fi->_next;
  249. fi->offset = 0;
  250. fi->length = min(folio_size(fi->folio), fi->_seg_count);
  251. fi->_next = folio_next(fi->folio);
  252. } else if (fi->_i + 1 < bio->bi_vcnt) {
  253. bio_first_folio(fi, bio, fi->_i + 1);
  254. } else {
  255. fi->folio = NULL;
  256. }
  257. }
  258. /**
  259. * bio_for_each_folio_all - Iterate over each folio in a bio.
  260. * @fi: struct folio_iter which is updated for each folio.
  261. * @bio: struct bio to iterate over.
  262. */
  263. #define bio_for_each_folio_all(fi, bio) \
  264. for (bio_first_folio(&fi, bio, 0); fi.folio; bio_next_folio(&fi, bio))
  265. enum bip_flags {
  266. BIP_BLOCK_INTEGRITY = 1 << 0, /* block layer owns integrity data */
  267. BIP_MAPPED_INTEGRITY = 1 << 1, /* ref tag has been remapped */
  268. BIP_CTRL_NOCHECK = 1 << 2, /* disable HBA integrity checking */
  269. BIP_DISK_NOCHECK = 1 << 3, /* disable disk integrity checking */
  270. BIP_IP_CHECKSUM = 1 << 4, /* IP checksum */
  271. };
  272. /*
  273. * bio integrity payload
  274. */
  275. struct bio_integrity_payload {
  276. struct bio *bip_bio; /* parent bio */
  277. struct bvec_iter bip_iter;
  278. unsigned short bip_vcnt; /* # of integrity bio_vecs */
  279. unsigned short bip_max_vcnt; /* integrity bio_vec slots */
  280. unsigned short bip_flags; /* control flags */
  281. struct bvec_iter bio_iter; /* for rewinding parent bio */
  282. struct work_struct bip_work; /* I/O completion */
  283. struct bio_vec *bip_vec;
  284. struct bio_vec bip_inline_vecs[];/* embedded bvec array */
  285. };
  286. #if defined(CONFIG_BLK_DEV_INTEGRITY)
  287. static inline struct bio_integrity_payload *bio_integrity(struct bio *bio)
  288. {
  289. if (bio->bi_opf & REQ_INTEGRITY)
  290. return bio->bi_integrity;
  291. return NULL;
  292. }
  293. static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
  294. {
  295. struct bio_integrity_payload *bip = bio_integrity(bio);
  296. if (bip)
  297. return bip->bip_flags & flag;
  298. return false;
  299. }
  300. static inline sector_t bip_get_seed(struct bio_integrity_payload *bip)
  301. {
  302. return bip->bip_iter.bi_sector;
  303. }
  304. static inline void bip_set_seed(struct bio_integrity_payload *bip,
  305. sector_t seed)
  306. {
  307. bip->bip_iter.bi_sector = seed;
  308. }
  309. #endif /* CONFIG_BLK_DEV_INTEGRITY */
  310. void bio_trim(struct bio *bio, sector_t offset, sector_t size);
  311. extern struct bio *bio_split(struct bio *bio, int sectors,
  312. gfp_t gfp, struct bio_set *bs);
  313. /**
  314. * bio_next_split - get next @sectors from a bio, splitting if necessary
  315. * @bio: bio to split
  316. * @sectors: number of sectors to split from the front of @bio
  317. * @gfp: gfp mask
  318. * @bs: bio set to allocate from
  319. *
  320. * Return: a bio representing the next @sectors of @bio - if the bio is smaller
  321. * than @sectors, returns the original bio unchanged.
  322. */
  323. static inline struct bio *bio_next_split(struct bio *bio, int sectors,
  324. gfp_t gfp, struct bio_set *bs)
  325. {
  326. if (sectors >= bio_sectors(bio))
  327. return bio;
  328. return bio_split(bio, sectors, gfp, bs);
  329. }
  330. enum {
  331. BIOSET_NEED_BVECS = BIT(0),
  332. BIOSET_NEED_RESCUER = BIT(1),
  333. BIOSET_PERCPU_CACHE = BIT(2),
  334. };
  335. extern int bioset_init(struct bio_set *, unsigned int, unsigned int, int flags);
  336. extern void bioset_exit(struct bio_set *);
  337. extern int biovec_init_pool(mempool_t *pool, int pool_entries);
  338. struct bio *bio_alloc_bioset(struct block_device *bdev, unsigned short nr_vecs,
  339. blk_opf_t opf, gfp_t gfp_mask,
  340. struct bio_set *bs);
  341. struct bio *bio_kmalloc(unsigned short nr_vecs, gfp_t gfp_mask);
  342. extern void bio_put(struct bio *);
  343. struct bio *bio_alloc_clone(struct block_device *bdev, struct bio *bio_src,
  344. gfp_t gfp, struct bio_set *bs);
  345. int bio_init_clone(struct block_device *bdev, struct bio *bio,
  346. struct bio *bio_src, gfp_t gfp);
  347. extern struct bio_set fs_bio_set;
  348. static inline struct bio *bio_alloc(struct block_device *bdev,
  349. unsigned short nr_vecs, blk_opf_t opf, gfp_t gfp_mask)
  350. {
  351. return bio_alloc_bioset(bdev, nr_vecs, opf, gfp_mask, &fs_bio_set);
  352. }
  353. void submit_bio(struct bio *bio);
  354. extern void bio_endio(struct bio *);
  355. static inline void bio_io_error(struct bio *bio)
  356. {
  357. bio->bi_status = BLK_STS_IOERR;
  358. bio_endio(bio);
  359. }
  360. static inline void bio_wouldblock_error(struct bio *bio)
  361. {
  362. bio_set_flag(bio, BIO_QUIET);
  363. bio->bi_status = BLK_STS_AGAIN;
  364. bio_endio(bio);
  365. }
  366. /*
  367. * Calculate number of bvec segments that should be allocated to fit data
  368. * pointed by @iter. If @iter is backed by bvec it's going to be reused
  369. * instead of allocating a new one.
  370. */
  371. static inline int bio_iov_vecs_to_alloc(struct iov_iter *iter, int max_segs)
  372. {
  373. if (iov_iter_is_bvec(iter))
  374. return 0;
  375. return iov_iter_npages(iter, max_segs);
  376. }
  377. struct request_queue;
  378. extern int submit_bio_wait(struct bio *bio);
  379. void bio_init(struct bio *bio, struct block_device *bdev, struct bio_vec *table,
  380. unsigned short max_vecs, blk_opf_t opf);
  381. extern void bio_uninit(struct bio *);
  382. void bio_reset(struct bio *bio, struct block_device *bdev, blk_opf_t opf);
  383. void bio_chain(struct bio *, struct bio *);
  384. int bio_add_page(struct bio *, struct page *, unsigned len, unsigned off);
  385. bool bio_add_folio(struct bio *, struct folio *, size_t len, size_t off);
  386. extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
  387. unsigned int, unsigned int);
  388. int bio_add_zone_append_page(struct bio *bio, struct page *page,
  389. unsigned int len, unsigned int offset);
  390. void __bio_add_page(struct bio *bio, struct page *page,
  391. unsigned int len, unsigned int off);
  392. int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter);
  393. void bio_iov_bvec_set(struct bio *bio, struct iov_iter *iter);
  394. void __bio_release_pages(struct bio *bio, bool mark_dirty);
  395. extern void bio_set_pages_dirty(struct bio *bio);
  396. extern void bio_check_pages_dirty(struct bio *bio);
  397. extern void bio_copy_data_iter(struct bio *dst, struct bvec_iter *dst_iter,
  398. struct bio *src, struct bvec_iter *src_iter);
  399. extern void bio_copy_data(struct bio *dst, struct bio *src);
  400. extern void bio_free_pages(struct bio *bio);
  401. void guard_bio_eod(struct bio *bio);
  402. void zero_fill_bio(struct bio *bio);
  403. static inline void bio_release_pages(struct bio *bio, bool mark_dirty)
  404. {
  405. if (!bio_flagged(bio, BIO_NO_PAGE_REF))
  406. __bio_release_pages(bio, mark_dirty);
  407. }
  408. #define bio_dev(bio) \
  409. disk_devt((bio)->bi_bdev->bd_disk)
  410. #ifdef CONFIG_BLK_CGROUP
  411. void bio_associate_blkg(struct bio *bio);
  412. void bio_associate_blkg_from_css(struct bio *bio,
  413. struct cgroup_subsys_state *css);
  414. void bio_clone_blkg_association(struct bio *dst, struct bio *src);
  415. #else /* CONFIG_BLK_CGROUP */
  416. static inline void bio_associate_blkg(struct bio *bio) { }
  417. static inline void bio_associate_blkg_from_css(struct bio *bio,
  418. struct cgroup_subsys_state *css)
  419. { }
  420. static inline void bio_clone_blkg_association(struct bio *dst,
  421. struct bio *src) { }
  422. #endif /* CONFIG_BLK_CGROUP */
  423. static inline void bio_set_dev(struct bio *bio, struct block_device *bdev)
  424. {
  425. bio_clear_flag(bio, BIO_REMAPPED);
  426. if (bio->bi_bdev != bdev)
  427. bio_clear_flag(bio, BIO_BPS_THROTTLED);
  428. bio->bi_bdev = bdev;
  429. bio_associate_blkg(bio);
  430. }
  431. /*
  432. * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
  433. *
  434. * A bio_list anchors a singly-linked list of bios chained through the bi_next
  435. * member of the bio. The bio_list also caches the last list member to allow
  436. * fast access to the tail.
  437. */
  438. struct bio_list {
  439. struct bio *head;
  440. struct bio *tail;
  441. };
  442. static inline int bio_list_empty(const struct bio_list *bl)
  443. {
  444. return bl->head == NULL;
  445. }
  446. static inline void bio_list_init(struct bio_list *bl)
  447. {
  448. bl->head = bl->tail = NULL;
  449. }
  450. #define BIO_EMPTY_LIST { NULL, NULL }
  451. #define bio_list_for_each(bio, bl) \
  452. for (bio = (bl)->head; bio; bio = bio->bi_next)
  453. static inline unsigned bio_list_size(const struct bio_list *bl)
  454. {
  455. unsigned sz = 0;
  456. struct bio *bio;
  457. bio_list_for_each(bio, bl)
  458. sz++;
  459. return sz;
  460. }
  461. static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
  462. {
  463. bio->bi_next = NULL;
  464. if (bl->tail)
  465. bl->tail->bi_next = bio;
  466. else
  467. bl->head = bio;
  468. bl->tail = bio;
  469. }
  470. static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
  471. {
  472. bio->bi_next = bl->head;
  473. bl->head = bio;
  474. if (!bl->tail)
  475. bl->tail = bio;
  476. }
  477. static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
  478. {
  479. if (!bl2->head)
  480. return;
  481. if (bl->tail)
  482. bl->tail->bi_next = bl2->head;
  483. else
  484. bl->head = bl2->head;
  485. bl->tail = bl2->tail;
  486. }
  487. static inline void bio_list_merge_head(struct bio_list *bl,
  488. struct bio_list *bl2)
  489. {
  490. if (!bl2->head)
  491. return;
  492. if (bl->head)
  493. bl2->tail->bi_next = bl->head;
  494. else
  495. bl->tail = bl2->tail;
  496. bl->head = bl2->head;
  497. }
  498. static inline struct bio *bio_list_peek(struct bio_list *bl)
  499. {
  500. return bl->head;
  501. }
  502. static inline struct bio *bio_list_pop(struct bio_list *bl)
  503. {
  504. struct bio *bio = bl->head;
  505. if (bio) {
  506. bl->head = bl->head->bi_next;
  507. if (!bl->head)
  508. bl->tail = NULL;
  509. bio->bi_next = NULL;
  510. }
  511. return bio;
  512. }
  513. static inline struct bio *bio_list_get(struct bio_list *bl)
  514. {
  515. struct bio *bio = bl->head;
  516. bl->head = bl->tail = NULL;
  517. return bio;
  518. }
  519. /*
  520. * Increment chain count for the bio. Make sure the CHAIN flag update
  521. * is visible before the raised count.
  522. */
  523. static inline void bio_inc_remaining(struct bio *bio)
  524. {
  525. bio_set_flag(bio, BIO_CHAIN);
  526. smp_mb__before_atomic();
  527. atomic_inc(&bio->__bi_remaining);
  528. }
  529. /*
  530. * bio_set is used to allow other portions of the IO system to
  531. * allocate their own private memory pools for bio and iovec structures.
  532. * These memory pools in turn all allocate from the bio_slab
  533. * and the bvec_slabs[].
  534. */
  535. #define BIO_POOL_SIZE 2
  536. struct bio_set {
  537. struct kmem_cache *bio_slab;
  538. unsigned int front_pad;
  539. /*
  540. * per-cpu bio alloc cache
  541. */
  542. struct bio_alloc_cache __percpu *cache;
  543. mempool_t bio_pool;
  544. mempool_t bvec_pool;
  545. #if defined(CONFIG_BLK_DEV_INTEGRITY)
  546. mempool_t bio_integrity_pool;
  547. mempool_t bvec_integrity_pool;
  548. #endif
  549. unsigned int back_pad;
  550. /*
  551. * Deadlock avoidance for stacking block drivers: see comments in
  552. * bio_alloc_bioset() for details
  553. */
  554. spinlock_t rescue_lock;
  555. struct bio_list rescue_list;
  556. struct work_struct rescue_work;
  557. struct workqueue_struct *rescue_workqueue;
  558. /*
  559. * Hot un-plug notifier for the per-cpu cache, if used
  560. */
  561. struct hlist_node cpuhp_dead;
  562. };
  563. static inline bool bioset_initialized(struct bio_set *bs)
  564. {
  565. return bs->bio_slab != NULL;
  566. }
  567. #if defined(CONFIG_BLK_DEV_INTEGRITY)
  568. #define bip_for_each_vec(bvl, bip, iter) \
  569. for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
  570. #define bio_for_each_integrity_vec(_bvl, _bio, _iter) \
  571. for_each_bio(_bio) \
  572. bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
  573. extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
  574. extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
  575. extern bool bio_integrity_prep(struct bio *);
  576. extern void bio_integrity_advance(struct bio *, unsigned int);
  577. extern void bio_integrity_trim(struct bio *);
  578. extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t);
  579. extern int bioset_integrity_create(struct bio_set *, int);
  580. extern void bioset_integrity_free(struct bio_set *);
  581. extern void bio_integrity_init(void);
  582. #else /* CONFIG_BLK_DEV_INTEGRITY */
  583. static inline void *bio_integrity(struct bio *bio)
  584. {
  585. return NULL;
  586. }
  587. static inline int bioset_integrity_create(struct bio_set *bs, int pool_size)
  588. {
  589. return 0;
  590. }
  591. static inline void bioset_integrity_free (struct bio_set *bs)
  592. {
  593. return;
  594. }
  595. static inline bool bio_integrity_prep(struct bio *bio)
  596. {
  597. return true;
  598. }
  599. static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
  600. gfp_t gfp_mask)
  601. {
  602. return 0;
  603. }
  604. static inline void bio_integrity_advance(struct bio *bio,
  605. unsigned int bytes_done)
  606. {
  607. return;
  608. }
  609. static inline void bio_integrity_trim(struct bio *bio)
  610. {
  611. return;
  612. }
  613. static inline void bio_integrity_init(void)
  614. {
  615. return;
  616. }
  617. static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
  618. {
  619. return false;
  620. }
  621. static inline void *bio_integrity_alloc(struct bio * bio, gfp_t gfp,
  622. unsigned int nr)
  623. {
  624. return ERR_PTR(-EINVAL);
  625. }
  626. static inline int bio_integrity_add_page(struct bio *bio, struct page *page,
  627. unsigned int len, unsigned int offset)
  628. {
  629. return 0;
  630. }
  631. #endif /* CONFIG_BLK_DEV_INTEGRITY */
  632. /*
  633. * Mark a bio as polled. Note that for async polled IO, the caller must
  634. * expect -EWOULDBLOCK if we cannot allocate a request (or other resources).
  635. * We cannot block waiting for requests on polled IO, as those completions
  636. * must be found by the caller. This is different than IRQ driven IO, where
  637. * it's safe to wait for IO to complete.
  638. */
  639. static inline void bio_set_polled(struct bio *bio, struct kiocb *kiocb)
  640. {
  641. bio->bi_opf |= REQ_POLLED;
  642. if (!is_sync_kiocb(kiocb))
  643. bio->bi_opf |= REQ_NOWAIT;
  644. }
  645. static inline void bio_clear_polled(struct bio *bio)
  646. {
  647. /* can't support alloc cache if we turn off polling */
  648. bio->bi_opf &= ~(REQ_POLLED | REQ_ALLOC_CACHE);
  649. }
  650. struct bio *blk_next_bio(struct bio *bio, struct block_device *bdev,
  651. unsigned int nr_pages, blk_opf_t opf, gfp_t gfp);
  652. #endif /* __LINUX_BIO_H */