bio.h 21 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_CACHE_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. * Check if adding a bio_vec after bprv with offset would create a gap in
  155. * the SG list. Most drivers don't care about this, but some do.
  156. */
  157. static inline bool bvec_gap_to_prev(struct bio_vec *bprv, unsigned int offset)
  158. {
  159. return offset || ((bprv->bv_offset + bprv->bv_len) & (PAGE_SIZE - 1));
  160. }
  161. /*
  162. * drivers should _never_ use the all version - the bio may have been split
  163. * before it got to the driver and the driver won't own all of it
  164. */
  165. #define bio_for_each_segment_all(bvl, bio, i) \
  166. for (i = 0, bvl = (bio)->bi_io_vec; i < (bio)->bi_vcnt; i++, bvl++)
  167. static inline void bvec_iter_advance(struct bio_vec *bv, struct bvec_iter *iter,
  168. unsigned bytes)
  169. {
  170. WARN_ONCE(bytes > iter->bi_size,
  171. "Attempted to advance past end of bvec iter\n");
  172. while (bytes) {
  173. unsigned len = min(bytes, bvec_iter_len(bv, *iter));
  174. bytes -= len;
  175. iter->bi_size -= len;
  176. iter->bi_bvec_done += len;
  177. if (iter->bi_bvec_done == __bvec_iter_bvec(bv, *iter)->bv_len) {
  178. iter->bi_bvec_done = 0;
  179. iter->bi_idx++;
  180. }
  181. }
  182. }
  183. #define for_each_bvec(bvl, bio_vec, iter, start) \
  184. for (iter = (start); \
  185. (iter).bi_size && \
  186. ((bvl = bvec_iter_bvec((bio_vec), (iter))), 1); \
  187. bvec_iter_advance((bio_vec), &(iter), (bvl).bv_len))
  188. static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter,
  189. unsigned bytes)
  190. {
  191. iter->bi_sector += bytes >> 9;
  192. if (bio->bi_rw & BIO_NO_ADVANCE_ITER_MASK)
  193. iter->bi_size -= bytes;
  194. else
  195. bvec_iter_advance(bio->bi_io_vec, iter, bytes);
  196. }
  197. #define __bio_for_each_segment(bvl, bio, iter, start) \
  198. for (iter = (start); \
  199. (iter).bi_size && \
  200. ((bvl = bio_iter_iovec((bio), (iter))), 1); \
  201. bio_advance_iter((bio), &(iter), (bvl).bv_len))
  202. #define bio_for_each_segment(bvl, bio, iter) \
  203. __bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter)
  204. #define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)
  205. static inline unsigned bio_segments(struct bio *bio)
  206. {
  207. unsigned segs = 0;
  208. struct bio_vec bv;
  209. struct bvec_iter iter;
  210. /*
  211. * We special case discard/write same, because they interpret bi_size
  212. * differently:
  213. */
  214. if (bio->bi_rw & REQ_DISCARD)
  215. return 1;
  216. if (bio->bi_rw & REQ_WRITE_SAME)
  217. return 1;
  218. bio_for_each_segment(bv, bio, iter)
  219. segs++;
  220. return segs;
  221. }
  222. /*
  223. * get a reference to a bio, so it won't disappear. the intended use is
  224. * something like:
  225. *
  226. * bio_get(bio);
  227. * submit_bio(rw, bio);
  228. * if (bio->bi_flags ...)
  229. * do_something
  230. * bio_put(bio);
  231. *
  232. * without the bio_get(), it could potentially complete I/O before submit_bio
  233. * returns. and then bio would be freed memory when if (bio->bi_flags ...)
  234. * runs
  235. */
  236. static inline void bio_get(struct bio *bio)
  237. {
  238. bio->bi_flags |= (1 << BIO_REFFED);
  239. smp_mb__before_atomic();
  240. atomic_inc(&bio->__bi_cnt);
  241. }
  242. static inline void bio_cnt_set(struct bio *bio, unsigned int count)
  243. {
  244. if (count != 1) {
  245. bio->bi_flags |= (1 << BIO_REFFED);
  246. smp_mb__before_atomic();
  247. }
  248. atomic_set(&bio->__bi_cnt, count);
  249. }
  250. static inline bool bio_flagged(struct bio *bio, unsigned int bit)
  251. {
  252. return (bio->bi_flags & (1U << bit)) != 0;
  253. }
  254. static inline void bio_set_flag(struct bio *bio, unsigned int bit)
  255. {
  256. bio->bi_flags |= (1U << bit);
  257. }
  258. static inline void bio_clear_flag(struct bio *bio, unsigned int bit)
  259. {
  260. bio->bi_flags &= ~(1U << bit);
  261. }
  262. enum bip_flags {
  263. BIP_BLOCK_INTEGRITY = 1 << 0, /* block layer owns integrity data */
  264. BIP_MAPPED_INTEGRITY = 1 << 1, /* ref tag has been remapped */
  265. BIP_CTRL_NOCHECK = 1 << 2, /* disable HBA integrity checking */
  266. BIP_DISK_NOCHECK = 1 << 3, /* disable disk integrity checking */
  267. BIP_IP_CHECKSUM = 1 << 4, /* IP checksum */
  268. };
  269. #if defined(CONFIG_BLK_DEV_INTEGRITY)
  270. static inline struct bio_integrity_payload *bio_integrity(struct bio *bio)
  271. {
  272. if (bio->bi_rw & REQ_INTEGRITY)
  273. return bio->bi_integrity;
  274. return NULL;
  275. }
  276. /*
  277. * bio integrity payload
  278. */
  279. struct bio_integrity_payload {
  280. struct bio *bip_bio; /* parent bio */
  281. struct bvec_iter bip_iter;
  282. bio_end_io_t *bip_end_io; /* saved I/O completion fn */
  283. unsigned short bip_slab; /* slab the bip came from */
  284. unsigned short bip_vcnt; /* # of integrity bio_vecs */
  285. unsigned short bip_max_vcnt; /* integrity bio_vec slots */
  286. unsigned short bip_flags; /* control flags */
  287. struct work_struct bip_work; /* I/O completion */
  288. struct bio_vec *bip_vec;
  289. struct bio_vec bip_inline_vecs[0];/* embedded bvec array */
  290. };
  291. static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
  292. {
  293. struct bio_integrity_payload *bip = bio_integrity(bio);
  294. if (bip)
  295. return bip->bip_flags & flag;
  296. return false;
  297. }
  298. static inline sector_t bip_get_seed(struct bio_integrity_payload *bip)
  299. {
  300. return bip->bip_iter.bi_sector;
  301. }
  302. static inline void bip_set_seed(struct bio_integrity_payload *bip,
  303. sector_t seed)
  304. {
  305. bip->bip_iter.bi_sector = seed;
  306. }
  307. #endif /* CONFIG_BLK_DEV_INTEGRITY */
  308. extern void bio_trim(struct bio *bio, int offset, int size);
  309. extern struct bio *bio_split(struct bio *bio, int sectors,
  310. gfp_t gfp, struct bio_set *bs);
  311. /**
  312. * bio_next_split - get next @sectors from a bio, splitting if necessary
  313. * @bio: bio to split
  314. * @sectors: number of sectors to split from the front of @bio
  315. * @gfp: gfp mask
  316. * @bs: bio set to allocate from
  317. *
  318. * Returns a bio representing the next @sectors of @bio - if the bio is smaller
  319. * than @sectors, returns the original bio unchanged.
  320. */
  321. static inline struct bio *bio_next_split(struct bio *bio, int sectors,
  322. gfp_t gfp, struct bio_set *bs)
  323. {
  324. if (sectors >= bio_sectors(bio))
  325. return bio;
  326. return bio_split(bio, sectors, gfp, bs);
  327. }
  328. extern struct bio_set *bioset_create(unsigned int, unsigned int);
  329. extern struct bio_set *bioset_create_nobvec(unsigned int, unsigned int);
  330. extern void bioset_free(struct bio_set *);
  331. extern mempool_t *biovec_create_pool(int pool_entries);
  332. extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
  333. extern void bio_put(struct bio *);
  334. extern void __bio_clone_fast(struct bio *, struct bio *);
  335. extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *);
  336. extern struct bio *bio_clone_bioset(struct bio *, gfp_t, struct bio_set *bs);
  337. extern struct bio_set *fs_bio_set;
  338. static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
  339. {
  340. return bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set);
  341. }
  342. static inline struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask)
  343. {
  344. return bio_clone_bioset(bio, gfp_mask, fs_bio_set);
  345. }
  346. static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
  347. {
  348. return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
  349. }
  350. static inline struct bio *bio_clone_kmalloc(struct bio *bio, gfp_t gfp_mask)
  351. {
  352. return bio_clone_bioset(bio, gfp_mask, NULL);
  353. }
  354. extern void bio_endio(struct bio *);
  355. static inline void bio_io_error(struct bio *bio)
  356. {
  357. bio->bi_error = -EIO;
  358. bio_endio(bio);
  359. }
  360. struct request_queue;
  361. extern int bio_phys_segments(struct request_queue *, struct bio *);
  362. extern int submit_bio_wait(int rw, struct bio *bio);
  363. extern void bio_advance(struct bio *, unsigned);
  364. extern void bio_init(struct bio *);
  365. extern void bio_reset(struct bio *);
  366. void bio_chain(struct bio *, struct bio *);
  367. extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
  368. extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
  369. unsigned int, unsigned int);
  370. struct rq_map_data;
  371. extern struct bio *bio_map_user_iov(struct request_queue *,
  372. const struct iov_iter *, gfp_t);
  373. extern void bio_unmap_user(struct bio *);
  374. extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
  375. gfp_t);
  376. extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
  377. gfp_t, int);
  378. extern void bio_set_pages_dirty(struct bio *bio);
  379. extern void bio_check_pages_dirty(struct bio *bio);
  380. void generic_start_io_acct(int rw, unsigned long sectors,
  381. struct hd_struct *part);
  382. void generic_end_io_acct(int rw, struct hd_struct *part,
  383. unsigned long start_time);
  384. #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
  385. # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
  386. #endif
  387. #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
  388. extern void bio_flush_dcache_pages(struct bio *bi);
  389. #else
  390. static inline void bio_flush_dcache_pages(struct bio *bi)
  391. {
  392. }
  393. #endif
  394. extern void bio_copy_data(struct bio *dst, struct bio *src);
  395. extern int bio_alloc_pages(struct bio *bio, gfp_t gfp);
  396. extern struct bio *bio_copy_user_iov(struct request_queue *,
  397. struct rq_map_data *,
  398. const struct iov_iter *,
  399. gfp_t);
  400. extern int bio_uncopy_user(struct bio *);
  401. void zero_fill_bio(struct bio *bio);
  402. extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *);
  403. extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int);
  404. extern unsigned int bvec_nr_vecs(unsigned short idx);
  405. #ifdef CONFIG_BLK_CGROUP
  406. int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css);
  407. int bio_associate_current(struct bio *bio);
  408. void bio_disassociate_task(struct bio *bio);
  409. #else /* CONFIG_BLK_CGROUP */
  410. static inline int bio_associate_blkcg(struct bio *bio,
  411. struct cgroup_subsys_state *blkcg_css) { return 0; }
  412. static inline int bio_associate_current(struct bio *bio) { return -ENOENT; }
  413. static inline void bio_disassociate_task(struct bio *bio) { }
  414. #endif /* CONFIG_BLK_CGROUP */
  415. #ifdef CONFIG_HIGHMEM
  416. /*
  417. * remember never ever reenable interrupts between a bvec_kmap_irq and
  418. * bvec_kunmap_irq!
  419. */
  420. static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
  421. {
  422. unsigned long addr;
  423. /*
  424. * might not be a highmem page, but the preempt/irq count
  425. * balancing is a lot nicer this way
  426. */
  427. local_irq_save(*flags);
  428. addr = (unsigned long) kmap_atomic(bvec->bv_page);
  429. BUG_ON(addr & ~PAGE_MASK);
  430. return (char *) addr + bvec->bv_offset;
  431. }
  432. static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
  433. {
  434. unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
  435. kunmap_atomic((void *) ptr);
  436. local_irq_restore(*flags);
  437. }
  438. #else
  439. static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
  440. {
  441. return page_address(bvec->bv_page) + bvec->bv_offset;
  442. }
  443. static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
  444. {
  445. *flags = 0;
  446. }
  447. #endif
  448. static inline char *__bio_kmap_irq(struct bio *bio, struct bvec_iter iter,
  449. unsigned long *flags)
  450. {
  451. return bvec_kmap_irq(&bio_iter_iovec(bio, iter), flags);
  452. }
  453. #define __bio_kunmap_irq(buf, flags) bvec_kunmap_irq(buf, flags)
  454. #define bio_kmap_irq(bio, flags) \
  455. __bio_kmap_irq((bio), (bio)->bi_iter, (flags))
  456. #define bio_kunmap_irq(buf,flags) __bio_kunmap_irq(buf, flags)
  457. /*
  458. * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
  459. *
  460. * A bio_list anchors a singly-linked list of bios chained through the bi_next
  461. * member of the bio. The bio_list also caches the last list member to allow
  462. * fast access to the tail.
  463. */
  464. struct bio_list {
  465. struct bio *head;
  466. struct bio *tail;
  467. };
  468. static inline int bio_list_empty(const struct bio_list *bl)
  469. {
  470. return bl->head == NULL;
  471. }
  472. static inline void bio_list_init(struct bio_list *bl)
  473. {
  474. bl->head = bl->tail = NULL;
  475. }
  476. #define BIO_EMPTY_LIST { NULL, NULL }
  477. #define bio_list_for_each(bio, bl) \
  478. for (bio = (bl)->head; bio; bio = bio->bi_next)
  479. static inline unsigned bio_list_size(const struct bio_list *bl)
  480. {
  481. unsigned sz = 0;
  482. struct bio *bio;
  483. bio_list_for_each(bio, bl)
  484. sz++;
  485. return sz;
  486. }
  487. static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
  488. {
  489. bio->bi_next = NULL;
  490. if (bl->tail)
  491. bl->tail->bi_next = bio;
  492. else
  493. bl->head = bio;
  494. bl->tail = bio;
  495. }
  496. static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
  497. {
  498. bio->bi_next = bl->head;
  499. bl->head = bio;
  500. if (!bl->tail)
  501. bl->tail = bio;
  502. }
  503. static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
  504. {
  505. if (!bl2->head)
  506. return;
  507. if (bl->tail)
  508. bl->tail->bi_next = bl2->head;
  509. else
  510. bl->head = bl2->head;
  511. bl->tail = bl2->tail;
  512. }
  513. static inline void bio_list_merge_head(struct bio_list *bl,
  514. struct bio_list *bl2)
  515. {
  516. if (!bl2->head)
  517. return;
  518. if (bl->head)
  519. bl2->tail->bi_next = bl->head;
  520. else
  521. bl->tail = bl2->tail;
  522. bl->head = bl2->head;
  523. }
  524. static inline struct bio *bio_list_peek(struct bio_list *bl)
  525. {
  526. return bl->head;
  527. }
  528. static inline struct bio *bio_list_pop(struct bio_list *bl)
  529. {
  530. struct bio *bio = bl->head;
  531. if (bio) {
  532. bl->head = bl->head->bi_next;
  533. if (!bl->head)
  534. bl->tail = NULL;
  535. bio->bi_next = NULL;
  536. }
  537. return bio;
  538. }
  539. static inline struct bio *bio_list_get(struct bio_list *bl)
  540. {
  541. struct bio *bio = bl->head;
  542. bl->head = bl->tail = NULL;
  543. return bio;
  544. }
  545. /*
  546. * bio_set is used to allow other portions of the IO system to
  547. * allocate their own private memory pools for bio and iovec structures.
  548. * These memory pools in turn all allocate from the bio_slab
  549. * and the bvec_slabs[].
  550. */
  551. #define BIO_POOL_SIZE 2
  552. #define BIOVEC_NR_POOLS 6
  553. #define BIOVEC_MAX_IDX (BIOVEC_NR_POOLS - 1)
  554. struct bio_set {
  555. struct kmem_cache *bio_slab;
  556. unsigned int front_pad;
  557. mempool_t *bio_pool;
  558. mempool_t *bvec_pool;
  559. #if defined(CONFIG_BLK_DEV_INTEGRITY)
  560. mempool_t *bio_integrity_pool;
  561. mempool_t *bvec_integrity_pool;
  562. #endif
  563. /*
  564. * Deadlock avoidance for stacking block drivers: see comments in
  565. * bio_alloc_bioset() for details
  566. */
  567. spinlock_t rescue_lock;
  568. struct bio_list rescue_list;
  569. struct work_struct rescue_work;
  570. struct workqueue_struct *rescue_workqueue;
  571. };
  572. struct biovec_slab {
  573. int nr_vecs;
  574. char *name;
  575. struct kmem_cache *slab;
  576. };
  577. /*
  578. * a small number of entries is fine, not going to be performance critical.
  579. * basically we just need to survive
  580. */
  581. #define BIO_SPLIT_ENTRIES 2
  582. #if defined(CONFIG_BLK_DEV_INTEGRITY)
  583. #define bip_for_each_vec(bvl, bip, iter) \
  584. for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
  585. #define bio_for_each_integrity_vec(_bvl, _bio, _iter) \
  586. for_each_bio(_bio) \
  587. bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
  588. extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
  589. extern void bio_integrity_free(struct bio *);
  590. extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
  591. extern bool bio_integrity_enabled(struct bio *bio);
  592. extern int bio_integrity_prep(struct bio *);
  593. extern void bio_integrity_endio(struct bio *);
  594. extern void bio_integrity_advance(struct bio *, unsigned int);
  595. extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
  596. extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t);
  597. extern int bioset_integrity_create(struct bio_set *, int);
  598. extern void bioset_integrity_free(struct bio_set *);
  599. extern void bio_integrity_init(void);
  600. #else /* CONFIG_BLK_DEV_INTEGRITY */
  601. static inline void *bio_integrity(struct bio *bio)
  602. {
  603. return NULL;
  604. }
  605. static inline bool bio_integrity_enabled(struct bio *bio)
  606. {
  607. return false;
  608. }
  609. static inline int bioset_integrity_create(struct bio_set *bs, int pool_size)
  610. {
  611. return 0;
  612. }
  613. static inline void bioset_integrity_free (struct bio_set *bs)
  614. {
  615. return;
  616. }
  617. static inline int bio_integrity_prep(struct bio *bio)
  618. {
  619. return 0;
  620. }
  621. static inline void bio_integrity_free(struct bio *bio)
  622. {
  623. return;
  624. }
  625. static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
  626. gfp_t gfp_mask)
  627. {
  628. return 0;
  629. }
  630. static inline void bio_integrity_advance(struct bio *bio,
  631. unsigned int bytes_done)
  632. {
  633. return;
  634. }
  635. static inline void bio_integrity_trim(struct bio *bio, unsigned int offset,
  636. unsigned int sectors)
  637. {
  638. return;
  639. }
  640. static inline void bio_integrity_init(void)
  641. {
  642. return;
  643. }
  644. static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
  645. {
  646. return false;
  647. }
  648. #endif /* CONFIG_BLK_DEV_INTEGRITY */
  649. #endif /* CONFIG_BLOCK */
  650. #endif /* __LINUX_BIO_H */