bio.h 22 KB

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  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. #include <linux/highmem.h>
  23. #include <linux/mempool.h>
  24. #include <linux/ioprio.h>
  25. #include <linux/bug.h>
  26. #ifdef CONFIG_BLOCK
  27. #include <asm/io.h>
  28. /* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */
  29. #include <linux/blk_types.h>
  30. #define BIO_DEBUG
  31. #ifdef BIO_DEBUG
  32. #define BIO_BUG_ON BUG_ON
  33. #else
  34. #define BIO_BUG_ON
  35. #endif
  36. #define BIO_MAX_PAGES 256
  37. #define BIO_MAX_SIZE (BIO_MAX_PAGES << PAGE_SHIFT)
  38. #define BIO_MAX_SECTORS (BIO_MAX_SIZE >> 9)
  39. /*
  40. * upper 16 bits of bi_rw define the io priority of this bio
  41. */
  42. #define BIO_PRIO_SHIFT (8 * sizeof(unsigned long) - IOPRIO_BITS)
  43. #define bio_prio(bio) ((bio)->bi_rw >> BIO_PRIO_SHIFT)
  44. #define bio_prio_valid(bio) ioprio_valid(bio_prio(bio))
  45. #define bio_set_prio(bio, prio) do { \
  46. WARN_ON(prio >= (1 << IOPRIO_BITS)); \
  47. (bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1); \
  48. (bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT); \
  49. } while (0)
  50. /*
  51. * various member access, note that bio_data should of course not be used
  52. * on highmem page vectors
  53. */
  54. #define __bvec_iter_bvec(bvec, iter) (&(bvec)[(iter).bi_idx])
  55. #define bvec_iter_page(bvec, iter) \
  56. (__bvec_iter_bvec((bvec), (iter))->bv_page)
  57. #define bvec_iter_len(bvec, iter) \
  58. min((iter).bi_size, \
  59. __bvec_iter_bvec((bvec), (iter))->bv_len - (iter).bi_bvec_done)
  60. #define bvec_iter_offset(bvec, iter) \
  61. (__bvec_iter_bvec((bvec), (iter))->bv_offset + (iter).bi_bvec_done)
  62. #define bvec_iter_bvec(bvec, iter) \
  63. ((struct bio_vec) { \
  64. .bv_page = bvec_iter_page((bvec), (iter)), \
  65. .bv_len = bvec_iter_len((bvec), (iter)), \
  66. .bv_offset = bvec_iter_offset((bvec), (iter)), \
  67. })
  68. #define bio_iter_iovec(bio, iter) \
  69. bvec_iter_bvec((bio)->bi_io_vec, (iter))
  70. #define bio_iter_page(bio, iter) \
  71. bvec_iter_page((bio)->bi_io_vec, (iter))
  72. #define bio_iter_len(bio, iter) \
  73. bvec_iter_len((bio)->bi_io_vec, (iter))
  74. #define bio_iter_offset(bio, iter) \
  75. bvec_iter_offset((bio)->bi_io_vec, (iter))
  76. #define bio_page(bio) bio_iter_page((bio), (bio)->bi_iter)
  77. #define bio_offset(bio) bio_iter_offset((bio), (bio)->bi_iter)
  78. #define bio_iovec(bio) bio_iter_iovec((bio), (bio)->bi_iter)
  79. #define bio_multiple_segments(bio) \
  80. ((bio)->bi_iter.bi_size != bio_iovec(bio).bv_len)
  81. #define bio_sectors(bio) ((bio)->bi_iter.bi_size >> 9)
  82. #define bio_end_sector(bio) ((bio)->bi_iter.bi_sector + bio_sectors((bio)))
  83. /*
  84. * Check whether this bio carries any data or not. A NULL bio is allowed.
  85. */
  86. static inline bool bio_has_data(struct bio *bio)
  87. {
  88. if (bio &&
  89. bio->bi_iter.bi_size &&
  90. !(bio->bi_rw & REQ_DISCARD))
  91. return true;
  92. return false;
  93. }
  94. static inline bool bio_is_rw(struct bio *bio)
  95. {
  96. if (!bio_has_data(bio))
  97. return false;
  98. if (bio->bi_rw & BIO_NO_ADVANCE_ITER_MASK)
  99. return false;
  100. return true;
  101. }
  102. static inline bool bio_mergeable(struct bio *bio)
  103. {
  104. if (bio->bi_rw & REQ_NOMERGE_FLAGS)
  105. return false;
  106. return true;
  107. }
  108. static inline unsigned int bio_cur_bytes(struct bio *bio)
  109. {
  110. if (bio_has_data(bio))
  111. return bio_iovec(bio).bv_len;
  112. else /* dataless requests such as discard */
  113. return bio->bi_iter.bi_size;
  114. }
  115. static inline void *bio_data(struct bio *bio)
  116. {
  117. if (bio_has_data(bio))
  118. return page_address(bio_page(bio)) + bio_offset(bio);
  119. return NULL;
  120. }
  121. /*
  122. * will die
  123. */
  124. #define bio_to_phys(bio) (page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
  125. #define bvec_to_phys(bv) (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
  126. /*
  127. * queues that have highmem support enabled may still need to revert to
  128. * PIO transfers occasionally and thus map high pages temporarily. For
  129. * permanent PIO fall back, user is probably better off disabling highmem
  130. * I/O completely on that queue (see ide-dma for example)
  131. */
  132. #define __bio_kmap_atomic(bio, iter) \
  133. (kmap_atomic(bio_iter_iovec((bio), (iter)).bv_page) + \
  134. bio_iter_iovec((bio), (iter)).bv_offset)
  135. #define __bio_kunmap_atomic(addr) kunmap_atomic(addr)
  136. /*
  137. * merge helpers etc
  138. */
  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. /*
  143. * allow arch override, for eg virtualized architectures (put in asm/io.h)
  144. */
  145. #ifndef BIOVEC_PHYS_MERGEABLE
  146. #define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
  147. __BIOVEC_PHYS_MERGEABLE(vec1, vec2)
  148. #endif
  149. #define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
  150. (((addr1) | (mask)) == (((addr2) - 1) | (mask)))
  151. #define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
  152. __BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q)))
  153. /*
  154. * drivers should _never_ use the all version - the bio may have been split
  155. * before it got to the driver and the driver won't own all of it
  156. */
  157. #define bio_for_each_segment_all(bvl, bio, i) \
  158. for (i = 0, bvl = (bio)->bi_io_vec; i < (bio)->bi_vcnt; i++, bvl++)
  159. static inline void bvec_iter_advance(struct bio_vec *bv, struct bvec_iter *iter,
  160. unsigned bytes)
  161. {
  162. WARN_ONCE(bytes > iter->bi_size,
  163. "Attempted to advance past end of bvec iter\n");
  164. while (bytes) {
  165. unsigned len = min(bytes, bvec_iter_len(bv, *iter));
  166. bytes -= len;
  167. iter->bi_size -= len;
  168. iter->bi_bvec_done += len;
  169. if (iter->bi_bvec_done == __bvec_iter_bvec(bv, *iter)->bv_len) {
  170. iter->bi_bvec_done = 0;
  171. iter->bi_idx++;
  172. }
  173. }
  174. }
  175. #define for_each_bvec(bvl, bio_vec, iter, start) \
  176. for (iter = (start); \
  177. (iter).bi_size && \
  178. ((bvl = bvec_iter_bvec((bio_vec), (iter))), 1); \
  179. bvec_iter_advance((bio_vec), &(iter), (bvl).bv_len))
  180. static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter,
  181. unsigned bytes)
  182. {
  183. iter->bi_sector += bytes >> 9;
  184. if (bio->bi_rw & BIO_NO_ADVANCE_ITER_MASK)
  185. iter->bi_size -= bytes;
  186. else
  187. bvec_iter_advance(bio->bi_io_vec, iter, bytes);
  188. }
  189. #define __bio_for_each_segment(bvl, bio, iter, start) \
  190. for (iter = (start); \
  191. (iter).bi_size && \
  192. ((bvl = bio_iter_iovec((bio), (iter))), 1); \
  193. bio_advance_iter((bio), &(iter), (bvl).bv_len))
  194. #define bio_for_each_segment(bvl, bio, iter) \
  195. __bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter)
  196. #define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)
  197. static inline unsigned bio_segments(struct bio *bio)
  198. {
  199. unsigned segs = 0;
  200. struct bio_vec bv;
  201. struct bvec_iter iter;
  202. /*
  203. * We special case discard/write same, because they interpret bi_size
  204. * differently:
  205. */
  206. if (bio->bi_rw & REQ_DISCARD)
  207. return 1;
  208. if (bio->bi_rw & REQ_WRITE_SAME)
  209. return 1;
  210. bio_for_each_segment(bv, bio, iter)
  211. segs++;
  212. return segs;
  213. }
  214. /*
  215. * get a reference to a bio, so it won't disappear. the intended use is
  216. * something like:
  217. *
  218. * bio_get(bio);
  219. * submit_bio(rw, bio);
  220. * if (bio->bi_flags ...)
  221. * do_something
  222. * bio_put(bio);
  223. *
  224. * without the bio_get(), it could potentially complete I/O before submit_bio
  225. * returns. and then bio would be freed memory when if (bio->bi_flags ...)
  226. * runs
  227. */
  228. static inline void bio_get(struct bio *bio)
  229. {
  230. bio->bi_flags |= (1 << BIO_REFFED);
  231. smp_mb__before_atomic();
  232. atomic_inc(&bio->__bi_cnt);
  233. }
  234. static inline void bio_cnt_set(struct bio *bio, unsigned int count)
  235. {
  236. if (count != 1) {
  237. bio->bi_flags |= (1 << BIO_REFFED);
  238. smp_mb__before_atomic();
  239. }
  240. atomic_set(&bio->__bi_cnt, count);
  241. }
  242. static inline bool bio_flagged(struct bio *bio, unsigned int bit)
  243. {
  244. return (bio->bi_flags & (1U << bit)) != 0;
  245. }
  246. static inline void bio_set_flag(struct bio *bio, unsigned int bit)
  247. {
  248. bio->bi_flags |= (1U << bit);
  249. }
  250. static inline void bio_clear_flag(struct bio *bio, unsigned int bit)
  251. {
  252. bio->bi_flags &= ~(1U << bit);
  253. }
  254. static inline void bio_get_first_bvec(struct bio *bio, struct bio_vec *bv)
  255. {
  256. *bv = bio_iovec(bio);
  257. }
  258. static inline void bio_get_last_bvec(struct bio *bio, struct bio_vec *bv)
  259. {
  260. struct bvec_iter iter = bio->bi_iter;
  261. int idx;
  262. if (unlikely(!bio_multiple_segments(bio))) {
  263. *bv = bio_iovec(bio);
  264. return;
  265. }
  266. bio_advance_iter(bio, &iter, iter.bi_size);
  267. if (!iter.bi_bvec_done)
  268. idx = iter.bi_idx - 1;
  269. else /* in the middle of bvec */
  270. idx = iter.bi_idx;
  271. *bv = bio->bi_io_vec[idx];
  272. /*
  273. * iter.bi_bvec_done records actual length of the last bvec
  274. * if this bio ends in the middle of one io vector
  275. */
  276. if (iter.bi_bvec_done)
  277. bv->bv_len = iter.bi_bvec_done;
  278. }
  279. enum bip_flags {
  280. BIP_BLOCK_INTEGRITY = 1 << 0, /* block layer owns integrity data */
  281. BIP_MAPPED_INTEGRITY = 1 << 1, /* ref tag has been remapped */
  282. BIP_CTRL_NOCHECK = 1 << 2, /* disable HBA integrity checking */
  283. BIP_DISK_NOCHECK = 1 << 3, /* disable disk integrity checking */
  284. BIP_IP_CHECKSUM = 1 << 4, /* IP checksum */
  285. };
  286. /*
  287. * bio integrity payload
  288. */
  289. struct bio_integrity_payload {
  290. struct bio *bip_bio; /* parent bio */
  291. struct bvec_iter bip_iter;
  292. bio_end_io_t *bip_end_io; /* saved I/O completion fn */
  293. unsigned short bip_slab; /* slab the bip came from */
  294. unsigned short bip_vcnt; /* # of integrity bio_vecs */
  295. unsigned short bip_max_vcnt; /* integrity bio_vec slots */
  296. unsigned short bip_flags; /* control flags */
  297. struct work_struct bip_work; /* I/O completion */
  298. struct bio_vec *bip_vec;
  299. struct bio_vec bip_inline_vecs[0];/* embedded bvec array */
  300. };
  301. #if defined(CONFIG_BLK_DEV_INTEGRITY)
  302. static inline struct bio_integrity_payload *bio_integrity(struct bio *bio)
  303. {
  304. if (bio->bi_rw & REQ_INTEGRITY)
  305. return bio->bi_integrity;
  306. return NULL;
  307. }
  308. static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
  309. {
  310. struct bio_integrity_payload *bip = bio_integrity(bio);
  311. if (bip)
  312. return bip->bip_flags & flag;
  313. return false;
  314. }
  315. static inline sector_t bip_get_seed(struct bio_integrity_payload *bip)
  316. {
  317. return bip->bip_iter.bi_sector;
  318. }
  319. static inline void bip_set_seed(struct bio_integrity_payload *bip,
  320. sector_t seed)
  321. {
  322. bip->bip_iter.bi_sector = seed;
  323. }
  324. #endif /* CONFIG_BLK_DEV_INTEGRITY */
  325. extern void bio_trim(struct bio *bio, int offset, int size);
  326. extern struct bio *bio_split(struct bio *bio, int sectors,
  327. gfp_t gfp, struct bio_set *bs);
  328. /**
  329. * bio_next_split - get next @sectors from a bio, splitting if necessary
  330. * @bio: bio to split
  331. * @sectors: number of sectors to split from the front of @bio
  332. * @gfp: gfp mask
  333. * @bs: bio set to allocate from
  334. *
  335. * Returns a bio representing the next @sectors of @bio - if the bio is smaller
  336. * than @sectors, returns the original bio unchanged.
  337. */
  338. static inline struct bio *bio_next_split(struct bio *bio, int sectors,
  339. gfp_t gfp, struct bio_set *bs)
  340. {
  341. if (sectors >= bio_sectors(bio))
  342. return bio;
  343. return bio_split(bio, sectors, gfp, bs);
  344. }
  345. extern struct bio_set *bioset_create(unsigned int, unsigned int);
  346. extern struct bio_set *bioset_create_nobvec(unsigned int, unsigned int);
  347. extern void bioset_free(struct bio_set *);
  348. extern mempool_t *biovec_create_pool(int pool_entries);
  349. extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
  350. extern void bio_put(struct bio *);
  351. extern void __bio_clone_fast(struct bio *, struct bio *);
  352. extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *);
  353. extern struct bio *bio_clone_bioset(struct bio *, gfp_t, struct bio_set *bs);
  354. extern struct bio_set *fs_bio_set;
  355. static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
  356. {
  357. return bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set);
  358. }
  359. static inline struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask)
  360. {
  361. return bio_clone_bioset(bio, gfp_mask, fs_bio_set);
  362. }
  363. static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
  364. {
  365. return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
  366. }
  367. static inline struct bio *bio_clone_kmalloc(struct bio *bio, gfp_t gfp_mask)
  368. {
  369. return bio_clone_bioset(bio, gfp_mask, NULL);
  370. }
  371. extern void bio_endio(struct bio *);
  372. static inline void bio_io_error(struct bio *bio)
  373. {
  374. bio->bi_error = -EIO;
  375. bio_endio(bio);
  376. }
  377. struct request_queue;
  378. extern int bio_phys_segments(struct request_queue *, struct bio *);
  379. extern int submit_bio_wait(int rw, struct bio *bio);
  380. extern void bio_advance(struct bio *, unsigned);
  381. extern void bio_init(struct bio *);
  382. extern void bio_reset(struct bio *);
  383. void bio_chain(struct bio *, struct bio *);
  384. extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
  385. extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
  386. unsigned int, unsigned int);
  387. struct rq_map_data;
  388. extern struct bio *bio_map_user_iov(struct request_queue *,
  389. const struct iov_iter *, gfp_t);
  390. extern void bio_unmap_user(struct bio *);
  391. extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
  392. gfp_t);
  393. extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
  394. gfp_t, int);
  395. extern void bio_set_pages_dirty(struct bio *bio);
  396. extern void bio_check_pages_dirty(struct bio *bio);
  397. void generic_start_io_acct(int rw, unsigned long sectors,
  398. struct hd_struct *part);
  399. void generic_end_io_acct(int rw, struct hd_struct *part,
  400. unsigned long start_time);
  401. #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
  402. # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
  403. #endif
  404. #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
  405. extern void bio_flush_dcache_pages(struct bio *bi);
  406. #else
  407. static inline void bio_flush_dcache_pages(struct bio *bi)
  408. {
  409. }
  410. #endif
  411. extern void bio_copy_data(struct bio *dst, struct bio *src);
  412. extern int bio_alloc_pages(struct bio *bio, gfp_t gfp);
  413. extern struct bio *bio_copy_user_iov(struct request_queue *,
  414. struct rq_map_data *,
  415. const struct iov_iter *,
  416. gfp_t);
  417. extern int bio_uncopy_user(struct bio *);
  418. void zero_fill_bio(struct bio *bio);
  419. extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *);
  420. extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int);
  421. extern unsigned int bvec_nr_vecs(unsigned short idx);
  422. #ifdef CONFIG_BLK_CGROUP
  423. int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css);
  424. int bio_associate_current(struct bio *bio);
  425. void bio_disassociate_task(struct bio *bio);
  426. #else /* CONFIG_BLK_CGROUP */
  427. static inline int bio_associate_blkcg(struct bio *bio,
  428. struct cgroup_subsys_state *blkcg_css) { return 0; }
  429. static inline int bio_associate_current(struct bio *bio) { return -ENOENT; }
  430. static inline void bio_disassociate_task(struct bio *bio) { }
  431. #endif /* CONFIG_BLK_CGROUP */
  432. #ifdef CONFIG_HIGHMEM
  433. /*
  434. * remember never ever reenable interrupts between a bvec_kmap_irq and
  435. * bvec_kunmap_irq!
  436. */
  437. static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
  438. {
  439. unsigned long addr;
  440. /*
  441. * might not be a highmem page, but the preempt/irq count
  442. * balancing is a lot nicer this way
  443. */
  444. local_irq_save(*flags);
  445. addr = (unsigned long) kmap_atomic(bvec->bv_page);
  446. BUG_ON(addr & ~PAGE_MASK);
  447. return (char *) addr + bvec->bv_offset;
  448. }
  449. static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
  450. {
  451. unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
  452. kunmap_atomic((void *) ptr);
  453. local_irq_restore(*flags);
  454. }
  455. #else
  456. static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
  457. {
  458. return page_address(bvec->bv_page) + bvec->bv_offset;
  459. }
  460. static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
  461. {
  462. *flags = 0;
  463. }
  464. #endif
  465. static inline char *__bio_kmap_irq(struct bio *bio, struct bvec_iter iter,
  466. unsigned long *flags)
  467. {
  468. return bvec_kmap_irq(&bio_iter_iovec(bio, iter), flags);
  469. }
  470. #define __bio_kunmap_irq(buf, flags) bvec_kunmap_irq(buf, flags)
  471. #define bio_kmap_irq(bio, flags) \
  472. __bio_kmap_irq((bio), (bio)->bi_iter, (flags))
  473. #define bio_kunmap_irq(buf,flags) __bio_kunmap_irq(buf, flags)
  474. /*
  475. * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
  476. *
  477. * A bio_list anchors a singly-linked list of bios chained through the bi_next
  478. * member of the bio. The bio_list also caches the last list member to allow
  479. * fast access to the tail.
  480. */
  481. struct bio_list {
  482. struct bio *head;
  483. struct bio *tail;
  484. };
  485. static inline int bio_list_empty(const struct bio_list *bl)
  486. {
  487. return bl->head == NULL;
  488. }
  489. static inline void bio_list_init(struct bio_list *bl)
  490. {
  491. bl->head = bl->tail = NULL;
  492. }
  493. #define BIO_EMPTY_LIST { NULL, NULL }
  494. #define bio_list_for_each(bio, bl) \
  495. for (bio = (bl)->head; bio; bio = bio->bi_next)
  496. static inline unsigned bio_list_size(const struct bio_list *bl)
  497. {
  498. unsigned sz = 0;
  499. struct bio *bio;
  500. bio_list_for_each(bio, bl)
  501. sz++;
  502. return sz;
  503. }
  504. static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
  505. {
  506. bio->bi_next = NULL;
  507. if (bl->tail)
  508. bl->tail->bi_next = bio;
  509. else
  510. bl->head = bio;
  511. bl->tail = bio;
  512. }
  513. static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
  514. {
  515. bio->bi_next = bl->head;
  516. bl->head = bio;
  517. if (!bl->tail)
  518. bl->tail = bio;
  519. }
  520. static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
  521. {
  522. if (!bl2->head)
  523. return;
  524. if (bl->tail)
  525. bl->tail->bi_next = bl2->head;
  526. else
  527. bl->head = bl2->head;
  528. bl->tail = bl2->tail;
  529. }
  530. static inline void bio_list_merge_head(struct bio_list *bl,
  531. struct bio_list *bl2)
  532. {
  533. if (!bl2->head)
  534. return;
  535. if (bl->head)
  536. bl2->tail->bi_next = bl->head;
  537. else
  538. bl->tail = bl2->tail;
  539. bl->head = bl2->head;
  540. }
  541. static inline struct bio *bio_list_peek(struct bio_list *bl)
  542. {
  543. return bl->head;
  544. }
  545. static inline struct bio *bio_list_pop(struct bio_list *bl)
  546. {
  547. struct bio *bio = bl->head;
  548. if (bio) {
  549. bl->head = bl->head->bi_next;
  550. if (!bl->head)
  551. bl->tail = NULL;
  552. bio->bi_next = NULL;
  553. }
  554. return bio;
  555. }
  556. static inline struct bio *bio_list_get(struct bio_list *bl)
  557. {
  558. struct bio *bio = bl->head;
  559. bl->head = bl->tail = NULL;
  560. return bio;
  561. }
  562. /*
  563. * Increment chain count for the bio. Make sure the CHAIN flag update
  564. * is visible before the raised count.
  565. */
  566. static inline void bio_inc_remaining(struct bio *bio)
  567. {
  568. bio_set_flag(bio, BIO_CHAIN);
  569. smp_mb__before_atomic();
  570. atomic_inc(&bio->__bi_remaining);
  571. }
  572. /*
  573. * bio_set is used to allow other portions of the IO system to
  574. * allocate their own private memory pools for bio and iovec structures.
  575. * These memory pools in turn all allocate from the bio_slab
  576. * and the bvec_slabs[].
  577. */
  578. #define BIO_POOL_SIZE 2
  579. #define BIOVEC_NR_POOLS 6
  580. #define BIOVEC_MAX_IDX (BIOVEC_NR_POOLS - 1)
  581. struct bio_set {
  582. struct kmem_cache *bio_slab;
  583. unsigned int front_pad;
  584. mempool_t *bio_pool;
  585. mempool_t *bvec_pool;
  586. #if defined(CONFIG_BLK_DEV_INTEGRITY)
  587. mempool_t *bio_integrity_pool;
  588. mempool_t *bvec_integrity_pool;
  589. #endif
  590. /*
  591. * Deadlock avoidance for stacking block drivers: see comments in
  592. * bio_alloc_bioset() for details
  593. */
  594. spinlock_t rescue_lock;
  595. struct bio_list rescue_list;
  596. struct work_struct rescue_work;
  597. struct workqueue_struct *rescue_workqueue;
  598. };
  599. struct biovec_slab {
  600. int nr_vecs;
  601. char *name;
  602. struct kmem_cache *slab;
  603. };
  604. /*
  605. * a small number of entries is fine, not going to be performance critical.
  606. * basically we just need to survive
  607. */
  608. #define BIO_SPLIT_ENTRIES 2
  609. #if defined(CONFIG_BLK_DEV_INTEGRITY)
  610. #define bip_for_each_vec(bvl, bip, iter) \
  611. for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
  612. #define bio_for_each_integrity_vec(_bvl, _bio, _iter) \
  613. for_each_bio(_bio) \
  614. bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
  615. extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
  616. extern void bio_integrity_free(struct bio *);
  617. extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
  618. extern bool bio_integrity_enabled(struct bio *bio);
  619. extern int bio_integrity_prep(struct bio *);
  620. extern void bio_integrity_endio(struct bio *);
  621. extern void bio_integrity_advance(struct bio *, unsigned int);
  622. extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
  623. extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t);
  624. extern int bioset_integrity_create(struct bio_set *, int);
  625. extern void bioset_integrity_free(struct bio_set *);
  626. extern void bio_integrity_init(void);
  627. #else /* CONFIG_BLK_DEV_INTEGRITY */
  628. static inline void *bio_integrity(struct bio *bio)
  629. {
  630. return NULL;
  631. }
  632. static inline bool bio_integrity_enabled(struct bio *bio)
  633. {
  634. return false;
  635. }
  636. static inline int bioset_integrity_create(struct bio_set *bs, int pool_size)
  637. {
  638. return 0;
  639. }
  640. static inline void bioset_integrity_free (struct bio_set *bs)
  641. {
  642. return;
  643. }
  644. static inline int bio_integrity_prep(struct bio *bio)
  645. {
  646. return 0;
  647. }
  648. static inline void bio_integrity_free(struct bio *bio)
  649. {
  650. return;
  651. }
  652. static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
  653. gfp_t gfp_mask)
  654. {
  655. return 0;
  656. }
  657. static inline void bio_integrity_advance(struct bio *bio,
  658. unsigned int bytes_done)
  659. {
  660. return;
  661. }
  662. static inline void bio_integrity_trim(struct bio *bio, unsigned int offset,
  663. unsigned int sectors)
  664. {
  665. return;
  666. }
  667. static inline void bio_integrity_init(void)
  668. {
  669. return;
  670. }
  671. static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
  672. {
  673. return false;
  674. }
  675. static inline void *bio_integrity_alloc(struct bio * bio, gfp_t gfp,
  676. unsigned int nr)
  677. {
  678. return ERR_PTR(-EINVAL);
  679. }
  680. static inline int bio_integrity_add_page(struct bio *bio, struct page *page,
  681. unsigned int len, unsigned int offset)
  682. {
  683. return 0;
  684. }
  685. #endif /* CONFIG_BLK_DEV_INTEGRITY */
  686. #endif /* CONFIG_BLOCK */
  687. #endif /* __LINUX_BIO_H */