bio.h 20 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. extern int trap_non_toi_io;
  31. #define BIO_DEBUG
  32. #ifdef BIO_DEBUG
  33. #define BIO_BUG_ON BUG_ON
  34. #else
  35. #define BIO_BUG_ON
  36. #endif
  37. #define BIO_MAX_PAGES 256
  38. #define BIO_MAX_SIZE (BIO_MAX_PAGES << PAGE_CACHE_SHIFT)
  39. #define BIO_MAX_SECTORS (BIO_MAX_SIZE >> 9)
  40. /*
  41. * upper 16 bits of bi_rw define the io priority of this bio
  42. */
  43. #define BIO_PRIO_SHIFT (8 * sizeof(unsigned long) - IOPRIO_BITS)
  44. #define bio_prio(bio) ((bio)->bi_rw >> BIO_PRIO_SHIFT)
  45. #define bio_prio_valid(bio) ioprio_valid(bio_prio(bio))
  46. #define bio_set_prio(bio, prio) do { \
  47. WARN_ON(prio >= (1 << IOPRIO_BITS)); \
  48. (bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1); \
  49. (bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT); \
  50. } while (0)
  51. /*
  52. * various member access, note that bio_data should of course not be used
  53. * on highmem page vectors
  54. */
  55. #define __bvec_iter_bvec(bvec, iter) (&(bvec)[(iter).bi_idx])
  56. #define bvec_iter_page(bvec, iter) \
  57. (__bvec_iter_bvec((bvec), (iter))->bv_page)
  58. #define bvec_iter_len(bvec, iter) \
  59. min((iter).bi_size, \
  60. __bvec_iter_bvec((bvec), (iter))->bv_len - (iter).bi_bvec_done)
  61. #define bvec_iter_offset(bvec, iter) \
  62. (__bvec_iter_bvec((bvec), (iter))->bv_offset + (iter).bi_bvec_done)
  63. #define bvec_iter_bvec(bvec, iter) \
  64. ((struct bio_vec) { \
  65. .bv_page = bvec_iter_page((bvec), (iter)), \
  66. .bv_len = bvec_iter_len((bvec), (iter)), \
  67. .bv_offset = bvec_iter_offset((bvec), (iter)), \
  68. })
  69. #define bio_iter_iovec(bio, iter) \
  70. bvec_iter_bvec((bio)->bi_io_vec, (iter))
  71. #define bio_iter_page(bio, iter) \
  72. bvec_iter_page((bio)->bi_io_vec, (iter))
  73. #define bio_iter_len(bio, iter) \
  74. bvec_iter_len((bio)->bi_io_vec, (iter))
  75. #define bio_iter_offset(bio, iter) \
  76. bvec_iter_offset((bio)->bi_io_vec, (iter))
  77. #define bio_page(bio) bio_iter_page((bio), (bio)->bi_iter)
  78. #define bio_offset(bio) bio_iter_offset((bio), (bio)->bi_iter)
  79. #define bio_iovec(bio) bio_iter_iovec((bio), (bio)->bi_iter)
  80. #define bio_multiple_segments(bio) \
  81. ((bio)->bi_iter.bi_size != bio_iovec(bio).bv_len)
  82. #define bio_sectors(bio) ((bio)->bi_iter.bi_size >> 9)
  83. #define bio_end_sector(bio) ((bio)->bi_iter.bi_sector + bio_sectors((bio)))
  84. /*
  85. * Check whether this bio carries any data or not. A NULL bio is allowed.
  86. */
  87. static inline bool bio_has_data(struct bio *bio)
  88. {
  89. if (bio &&
  90. bio->bi_iter.bi_size &&
  91. !(bio->bi_rw & REQ_DISCARD))
  92. return true;
  93. return false;
  94. }
  95. static inline bool bio_is_rw(struct bio *bio)
  96. {
  97. if (!bio_has_data(bio))
  98. return false;
  99. if (bio->bi_rw & BIO_NO_ADVANCE_ITER_MASK)
  100. return false;
  101. return true;
  102. }
  103. static inline bool bio_mergeable(struct bio *bio)
  104. {
  105. if (bio->bi_rw & REQ_NOMERGE_FLAGS)
  106. return false;
  107. return true;
  108. }
  109. static inline unsigned int bio_cur_bytes(struct bio *bio)
  110. {
  111. if (bio_has_data(bio))
  112. return bio_iovec(bio).bv_len;
  113. else /* dataless requests such as discard */
  114. return bio->bi_iter.bi_size;
  115. }
  116. static inline void *bio_data(struct bio *bio)
  117. {
  118. if (bio_has_data(bio))
  119. return page_address(bio_page(bio)) + bio_offset(bio);
  120. return NULL;
  121. }
  122. /*
  123. * will die
  124. */
  125. #define bio_to_phys(bio) (page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
  126. #define bvec_to_phys(bv) (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
  127. /*
  128. * queues that have highmem support enabled may still need to revert to
  129. * PIO transfers occasionally and thus map high pages temporarily. For
  130. * permanent PIO fall back, user is probably better off disabling highmem
  131. * I/O completely on that queue (see ide-dma for example)
  132. */
  133. #define __bio_kmap_atomic(bio, iter) \
  134. (kmap_atomic(bio_iter_iovec((bio), (iter)).bv_page) + \
  135. bio_iter_iovec((bio), (iter)).bv_offset)
  136. #define __bio_kunmap_atomic(addr) kunmap_atomic(addr)
  137. /*
  138. * merge helpers etc
  139. */
  140. /* Default implementation of BIOVEC_PHYS_MERGEABLE */
  141. #define __BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
  142. ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
  143. /*
  144. * allow arch override, for eg virtualized architectures (put in asm/io.h)
  145. */
  146. #ifndef BIOVEC_PHYS_MERGEABLE
  147. #define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
  148. __BIOVEC_PHYS_MERGEABLE(vec1, vec2)
  149. #endif
  150. #define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
  151. (((addr1) | (mask)) == (((addr2) - 1) | (mask)))
  152. #define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
  153. __BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q)))
  154. /*
  155. * Check if adding a bio_vec after bprv with offset would create a gap in
  156. * the SG list. Most drivers don't care about this, but some do.
  157. */
  158. static inline bool bvec_gap_to_prev(struct bio_vec *bprv, unsigned int offset)
  159. {
  160. return offset || ((bprv->bv_offset + bprv->bv_len) & (PAGE_SIZE - 1));
  161. }
  162. #define bio_io_error(bio) bio_endio((bio), -EIO)
  163. /*
  164. * drivers should _never_ use the all version - the bio may have been split
  165. * before it got to the driver and the driver won't own all of it
  166. */
  167. #define bio_for_each_segment_all(bvl, bio, i) \
  168. for (i = 0, bvl = (bio)->bi_io_vec; i < (bio)->bi_vcnt; i++, bvl++)
  169. static inline void bvec_iter_advance(struct bio_vec *bv, struct bvec_iter *iter,
  170. unsigned bytes)
  171. {
  172. WARN_ONCE(bytes > iter->bi_size,
  173. "Attempted to advance past end of bvec iter\n");
  174. while (bytes) {
  175. unsigned len = min(bytes, bvec_iter_len(bv, *iter));
  176. bytes -= len;
  177. iter->bi_size -= len;
  178. iter->bi_bvec_done += len;
  179. if (iter->bi_bvec_done == __bvec_iter_bvec(bv, *iter)->bv_len) {
  180. iter->bi_bvec_done = 0;
  181. iter->bi_idx++;
  182. }
  183. }
  184. }
  185. #define for_each_bvec(bvl, bio_vec, iter, start) \
  186. for (iter = (start); \
  187. (iter).bi_size && \
  188. ((bvl = bvec_iter_bvec((bio_vec), (iter))), 1); \
  189. bvec_iter_advance((bio_vec), &(iter), (bvl).bv_len))
  190. static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter,
  191. unsigned bytes)
  192. {
  193. iter->bi_sector += bytes >> 9;
  194. if (bio->bi_rw & BIO_NO_ADVANCE_ITER_MASK)
  195. iter->bi_size -= bytes;
  196. else
  197. bvec_iter_advance(bio->bi_io_vec, iter, bytes);
  198. }
  199. #define __bio_for_each_segment(bvl, bio, iter, start) \
  200. for (iter = (start); \
  201. (iter).bi_size && \
  202. ((bvl = bio_iter_iovec((bio), (iter))), 1); \
  203. bio_advance_iter((bio), &(iter), (bvl).bv_len))
  204. #define bio_for_each_segment(bvl, bio, iter) \
  205. __bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter)
  206. #define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)
  207. static inline unsigned bio_segments(struct bio *bio)
  208. {
  209. unsigned segs = 0;
  210. struct bio_vec bv;
  211. struct bvec_iter iter;
  212. /*
  213. * We special case discard/write same, because they interpret bi_size
  214. * differently:
  215. */
  216. if (bio->bi_rw & REQ_DISCARD)
  217. return 1;
  218. if (bio->bi_rw & REQ_WRITE_SAME)
  219. return 1;
  220. bio_for_each_segment(bv, bio, iter)
  221. segs++;
  222. return segs;
  223. }
  224. /*
  225. * get a reference to a bio, so it won't disappear. the intended use is
  226. * something like:
  227. *
  228. * bio_get(bio);
  229. * submit_bio(rw, bio);
  230. * if (bio->bi_flags ...)
  231. * do_something
  232. * bio_put(bio);
  233. *
  234. * without the bio_get(), it could potentially complete I/O before submit_bio
  235. * returns. and then bio would be freed memory when if (bio->bi_flags ...)
  236. * runs
  237. */
  238. #define bio_get(bio) atomic_inc(&(bio)->bi_cnt)
  239. enum bip_flags {
  240. BIP_BLOCK_INTEGRITY = 1 << 0, /* block layer owns integrity data */
  241. BIP_MAPPED_INTEGRITY = 1 << 1, /* ref tag has been remapped */
  242. BIP_CTRL_NOCHECK = 1 << 2, /* disable HBA integrity checking */
  243. BIP_DISK_NOCHECK = 1 << 3, /* disable disk integrity checking */
  244. BIP_IP_CHECKSUM = 1 << 4, /* IP checksum */
  245. };
  246. #if defined(CONFIG_BLK_DEV_INTEGRITY)
  247. static inline struct bio_integrity_payload *bio_integrity(struct bio *bio)
  248. {
  249. if (bio->bi_rw & REQ_INTEGRITY)
  250. return bio->bi_integrity;
  251. return NULL;
  252. }
  253. /*
  254. * bio integrity payload
  255. */
  256. struct bio_integrity_payload {
  257. struct bio *bip_bio; /* parent bio */
  258. struct bvec_iter bip_iter;
  259. bio_end_io_t *bip_end_io; /* saved I/O completion fn */
  260. unsigned short bip_slab; /* slab the bip came from */
  261. unsigned short bip_vcnt; /* # of integrity bio_vecs */
  262. unsigned short bip_max_vcnt; /* integrity bio_vec slots */
  263. unsigned short bip_flags; /* control flags */
  264. struct work_struct bip_work; /* I/O completion */
  265. struct bio_vec *bip_vec;
  266. struct bio_vec bip_inline_vecs[0];/* embedded bvec array */
  267. };
  268. static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
  269. {
  270. struct bio_integrity_payload *bip = bio_integrity(bio);
  271. if (bip)
  272. return bip->bip_flags & flag;
  273. return false;
  274. }
  275. static inline sector_t bip_get_seed(struct bio_integrity_payload *bip)
  276. {
  277. return bip->bip_iter.bi_sector;
  278. }
  279. static inline void bip_set_seed(struct bio_integrity_payload *bip,
  280. sector_t seed)
  281. {
  282. bip->bip_iter.bi_sector = seed;
  283. }
  284. #endif /* CONFIG_BLK_DEV_INTEGRITY */
  285. extern void bio_trim(struct bio *bio, int offset, int size);
  286. extern struct bio *bio_split(struct bio *bio, int sectors,
  287. gfp_t gfp, struct bio_set *bs);
  288. /**
  289. * bio_next_split - get next @sectors from a bio, splitting if necessary
  290. * @bio: bio to split
  291. * @sectors: number of sectors to split from the front of @bio
  292. * @gfp: gfp mask
  293. * @bs: bio set to allocate from
  294. *
  295. * Returns a bio representing the next @sectors of @bio - if the bio is smaller
  296. * than @sectors, returns the original bio unchanged.
  297. */
  298. static inline struct bio *bio_next_split(struct bio *bio, int sectors,
  299. gfp_t gfp, struct bio_set *bs)
  300. {
  301. if (sectors >= bio_sectors(bio))
  302. return bio;
  303. return bio_split(bio, sectors, gfp, bs);
  304. }
  305. extern struct bio_set *bioset_create(unsigned int, unsigned int);
  306. extern struct bio_set *bioset_create_nobvec(unsigned int, unsigned int);
  307. extern void bioset_free(struct bio_set *);
  308. extern mempool_t *biovec_create_pool(int pool_entries);
  309. extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
  310. extern void bio_put(struct bio *);
  311. extern void __bio_clone_fast(struct bio *, struct bio *);
  312. extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *);
  313. extern struct bio *bio_clone_bioset(struct bio *, gfp_t, struct bio_set *bs);
  314. extern struct bio_set *fs_bio_set;
  315. static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
  316. {
  317. return bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set);
  318. }
  319. static inline struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask)
  320. {
  321. return bio_clone_bioset(bio, gfp_mask, fs_bio_set);
  322. }
  323. static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
  324. {
  325. return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
  326. }
  327. static inline struct bio *bio_clone_kmalloc(struct bio *bio, gfp_t gfp_mask)
  328. {
  329. return bio_clone_bioset(bio, gfp_mask, NULL);
  330. }
  331. extern void bio_endio(struct bio *, int);
  332. extern void bio_endio_nodec(struct bio *, int);
  333. struct request_queue;
  334. extern int bio_phys_segments(struct request_queue *, struct bio *);
  335. extern int submit_bio_wait(int rw, struct bio *bio);
  336. extern void bio_advance(struct bio *, unsigned);
  337. extern void bio_init(struct bio *);
  338. extern void bio_reset(struct bio *);
  339. void bio_chain(struct bio *, struct bio *);
  340. extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
  341. extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
  342. unsigned int, unsigned int);
  343. extern int bio_get_nr_vecs(struct block_device *);
  344. extern struct bio *bio_map_user(struct request_queue *, struct block_device *,
  345. unsigned long, unsigned int, int, gfp_t);
  346. struct sg_iovec;
  347. struct rq_map_data;
  348. extern struct bio *bio_map_user_iov(struct request_queue *,
  349. struct block_device *,
  350. const struct sg_iovec *, int, int, gfp_t);
  351. extern void bio_unmap_user(struct bio *);
  352. extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
  353. gfp_t);
  354. extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
  355. gfp_t, int);
  356. extern void bio_set_pages_dirty(struct bio *bio);
  357. extern void bio_check_pages_dirty(struct bio *bio);
  358. #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
  359. # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
  360. #endif
  361. #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
  362. extern void bio_flush_dcache_pages(struct bio *bi);
  363. #else
  364. static inline void bio_flush_dcache_pages(struct bio *bi)
  365. {
  366. }
  367. #endif
  368. extern void bio_copy_data(struct bio *dst, struct bio *src);
  369. extern int bio_alloc_pages(struct bio *bio, gfp_t gfp);
  370. extern struct bio *bio_copy_user(struct request_queue *, struct rq_map_data *,
  371. unsigned long, unsigned int, int, gfp_t);
  372. extern struct bio *bio_copy_user_iov(struct request_queue *,
  373. struct rq_map_data *,
  374. const struct sg_iovec *,
  375. int, int, gfp_t);
  376. extern int bio_uncopy_user(struct bio *);
  377. void zero_fill_bio(struct bio *bio);
  378. extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *);
  379. extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int);
  380. extern unsigned int bvec_nr_vecs(unsigned short idx);
  381. #ifdef CONFIG_BLK_CGROUP
  382. int bio_associate_current(struct bio *bio);
  383. void bio_disassociate_task(struct bio *bio);
  384. #else /* CONFIG_BLK_CGROUP */
  385. static inline int bio_associate_current(struct bio *bio) { return -ENOENT; }
  386. static inline void bio_disassociate_task(struct bio *bio) { }
  387. #endif /* CONFIG_BLK_CGROUP */
  388. #ifdef CONFIG_HIGHMEM
  389. /*
  390. * remember never ever reenable interrupts between a bvec_kmap_irq and
  391. * bvec_kunmap_irq!
  392. */
  393. static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
  394. {
  395. unsigned long addr;
  396. /*
  397. * might not be a highmem page, but the preempt/irq count
  398. * balancing is a lot nicer this way
  399. */
  400. local_irq_save(*flags);
  401. addr = (unsigned long) kmap_atomic(bvec->bv_page);
  402. BUG_ON(addr & ~PAGE_MASK);
  403. return (char *) addr + bvec->bv_offset;
  404. }
  405. static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
  406. {
  407. unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
  408. kunmap_atomic((void *) ptr);
  409. local_irq_restore(*flags);
  410. }
  411. #else
  412. static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
  413. {
  414. return page_address(bvec->bv_page) + bvec->bv_offset;
  415. }
  416. static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
  417. {
  418. *flags = 0;
  419. }
  420. #endif
  421. static inline char *__bio_kmap_irq(struct bio *bio, struct bvec_iter iter,
  422. unsigned long *flags)
  423. {
  424. return bvec_kmap_irq(&bio_iter_iovec(bio, iter), flags);
  425. }
  426. #define __bio_kunmap_irq(buf, flags) bvec_kunmap_irq(buf, flags)
  427. #define bio_kmap_irq(bio, flags) \
  428. __bio_kmap_irq((bio), (bio)->bi_iter, (flags))
  429. #define bio_kunmap_irq(buf,flags) __bio_kunmap_irq(buf, flags)
  430. /*
  431. * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
  432. *
  433. * A bio_list anchors a singly-linked list of bios chained through the bi_next
  434. * member of the bio. The bio_list also caches the last list member to allow
  435. * fast access to the tail.
  436. */
  437. struct bio_list {
  438. struct bio *head;
  439. struct bio *tail;
  440. };
  441. static inline int bio_list_empty(const struct bio_list *bl)
  442. {
  443. return bl->head == NULL;
  444. }
  445. static inline void bio_list_init(struct bio_list *bl)
  446. {
  447. bl->head = bl->tail = NULL;
  448. }
  449. #define BIO_EMPTY_LIST { NULL, NULL }
  450. #define bio_list_for_each(bio, bl) \
  451. for (bio = (bl)->head; bio; bio = bio->bi_next)
  452. static inline unsigned bio_list_size(const struct bio_list *bl)
  453. {
  454. unsigned sz = 0;
  455. struct bio *bio;
  456. bio_list_for_each(bio, bl)
  457. sz++;
  458. return sz;
  459. }
  460. static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
  461. {
  462. bio->bi_next = NULL;
  463. if (bl->tail)
  464. bl->tail->bi_next = bio;
  465. else
  466. bl->head = bio;
  467. bl->tail = bio;
  468. }
  469. static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
  470. {
  471. bio->bi_next = bl->head;
  472. bl->head = bio;
  473. if (!bl->tail)
  474. bl->tail = bio;
  475. }
  476. static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
  477. {
  478. if (!bl2->head)
  479. return;
  480. if (bl->tail)
  481. bl->tail->bi_next = bl2->head;
  482. else
  483. bl->head = bl2->head;
  484. bl->tail = bl2->tail;
  485. }
  486. static inline void bio_list_merge_head(struct bio_list *bl,
  487. struct bio_list *bl2)
  488. {
  489. if (!bl2->head)
  490. return;
  491. if (bl->head)
  492. bl2->tail->bi_next = bl->head;
  493. else
  494. bl->tail = bl2->tail;
  495. bl->head = bl2->head;
  496. }
  497. static inline struct bio *bio_list_peek(struct bio_list *bl)
  498. {
  499. return bl->head;
  500. }
  501. static inline struct bio *bio_list_pop(struct bio_list *bl)
  502. {
  503. struct bio *bio = bl->head;
  504. if (bio) {
  505. bl->head = bl->head->bi_next;
  506. if (!bl->head)
  507. bl->tail = NULL;
  508. bio->bi_next = NULL;
  509. }
  510. return bio;
  511. }
  512. static inline struct bio *bio_list_get(struct bio_list *bl)
  513. {
  514. struct bio *bio = bl->head;
  515. bl->head = bl->tail = NULL;
  516. return bio;
  517. }
  518. /*
  519. * bio_set is used to allow other portions of the IO system to
  520. * allocate their own private memory pools for bio and iovec structures.
  521. * These memory pools in turn all allocate from the bio_slab
  522. * and the bvec_slabs[].
  523. */
  524. #define BIO_POOL_SIZE 2
  525. #define BIOVEC_NR_POOLS 6
  526. #define BIOVEC_MAX_IDX (BIOVEC_NR_POOLS - 1)
  527. struct bio_set {
  528. struct kmem_cache *bio_slab;
  529. unsigned int front_pad;
  530. mempool_t *bio_pool;
  531. mempool_t *bvec_pool;
  532. #if defined(CONFIG_BLK_DEV_INTEGRITY)
  533. mempool_t *bio_integrity_pool;
  534. mempool_t *bvec_integrity_pool;
  535. #endif
  536. /*
  537. * Deadlock avoidance for stacking block drivers: see comments in
  538. * bio_alloc_bioset() for details
  539. */
  540. spinlock_t rescue_lock;
  541. struct bio_list rescue_list;
  542. struct work_struct rescue_work;
  543. struct workqueue_struct *rescue_workqueue;
  544. };
  545. struct biovec_slab {
  546. int nr_vecs;
  547. char *name;
  548. struct kmem_cache *slab;
  549. };
  550. /*
  551. * a small number of entries is fine, not going to be performance critical.
  552. * basically we just need to survive
  553. */
  554. #define BIO_SPLIT_ENTRIES 2
  555. #if defined(CONFIG_BLK_DEV_INTEGRITY)
  556. #define bip_for_each_vec(bvl, bip, iter) \
  557. for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
  558. #define bio_for_each_integrity_vec(_bvl, _bio, _iter) \
  559. for_each_bio(_bio) \
  560. bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
  561. extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
  562. extern void bio_integrity_free(struct bio *);
  563. extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
  564. extern bool bio_integrity_enabled(struct bio *bio);
  565. extern int bio_integrity_prep(struct bio *);
  566. extern void bio_integrity_endio(struct bio *, int);
  567. extern void bio_integrity_advance(struct bio *, unsigned int);
  568. extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
  569. extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t);
  570. extern int bioset_integrity_create(struct bio_set *, int);
  571. extern void bioset_integrity_free(struct bio_set *);
  572. extern void bio_integrity_init(void);
  573. #else /* CONFIG_BLK_DEV_INTEGRITY */
  574. static inline void *bio_integrity(struct bio *bio)
  575. {
  576. return NULL;
  577. }
  578. static inline bool bio_integrity_enabled(struct bio *bio)
  579. {
  580. return false;
  581. }
  582. static inline int bioset_integrity_create(struct bio_set *bs, int pool_size)
  583. {
  584. return 0;
  585. }
  586. static inline void bioset_integrity_free (struct bio_set *bs)
  587. {
  588. return;
  589. }
  590. static inline int bio_integrity_prep(struct bio *bio)
  591. {
  592. return 0;
  593. }
  594. static inline void bio_integrity_free(struct bio *bio)
  595. {
  596. return;
  597. }
  598. static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
  599. gfp_t gfp_mask)
  600. {
  601. return 0;
  602. }
  603. static inline void bio_integrity_advance(struct bio *bio,
  604. unsigned int bytes_done)
  605. {
  606. return;
  607. }
  608. static inline void bio_integrity_trim(struct bio *bio, unsigned int offset,
  609. unsigned int sectors)
  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. #endif /* CONFIG_BLK_DEV_INTEGRITY */
  622. #endif /* CONFIG_BLOCK */
  623. #endif /* __LINUX_BIO_H */