1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Copyright (C) 2001 Jens Axboe <axboe@suse.de> 4 */ 5 #ifndef __LINUX_BIO_H 6 #define __LINUX_BIO_H 7 8 #include <linux/highmem.h> 9 #include <linux/mempool.h> 10 #include <linux/ioprio.h> 11 12 #ifdef CONFIG_BLOCK 13 /* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */ 14 #include <linux/blk_types.h> 15 16 #define BIO_DEBUG 17 18 #ifdef BIO_DEBUG 19 #define BIO_BUG_ON BUG_ON 20 #else 21 #define BIO_BUG_ON 22 #endif 23 24 #define BIO_MAX_PAGES 256 25 26 #define bio_prio(bio) (bio)->bi_ioprio 27 #define bio_set_prio(bio, prio) ((bio)->bi_ioprio = prio) 28 29 #define bio_iter_iovec(bio, iter) \ 30 bvec_iter_bvec((bio)->bi_io_vec, (iter)) 31 32 #define bio_iter_page(bio, iter) \ 33 bvec_iter_page((bio)->bi_io_vec, (iter)) 34 #define bio_iter_len(bio, iter) \ 35 bvec_iter_len((bio)->bi_io_vec, (iter)) 36 #define bio_iter_offset(bio, iter) \ 37 bvec_iter_offset((bio)->bi_io_vec, (iter)) 38 39 #define bio_page(bio) bio_iter_page((bio), (bio)->bi_iter) 40 #define bio_offset(bio) bio_iter_offset((bio), (bio)->bi_iter) 41 #define bio_iovec(bio) bio_iter_iovec((bio), (bio)->bi_iter) 42 43 #define bio_multiple_segments(bio) \ 44 ((bio)->bi_iter.bi_size != bio_iovec(bio).bv_len) 45 46 #define bvec_iter_sectors(iter) ((iter).bi_size >> 9) 47 #define bvec_iter_end_sector(iter) ((iter).bi_sector + bvec_iter_sectors((iter))) 48 49 #define bio_sectors(bio) bvec_iter_sectors((bio)->bi_iter) 50 #define bio_end_sector(bio) bvec_iter_end_sector((bio)->bi_iter) 51 52 /* 53 * Return the data direction, READ or WRITE. 54 */ 55 #define bio_data_dir(bio) \ 56 (op_is_write(bio_op(bio)) ? WRITE : READ) 57 58 /* 59 * Check whether this bio carries any data or not. A NULL bio is allowed. 60 */ 61 static inline bool bio_has_data(struct bio *bio) 62 { 63 if (bio && 64 bio->bi_iter.bi_size && 65 bio_op(bio) != REQ_OP_DISCARD && 66 bio_op(bio) != REQ_OP_SECURE_ERASE && 67 bio_op(bio) != REQ_OP_WRITE_ZEROES) 68 return true; 69 70 return false; 71 } 72 73 static inline bool bio_no_advance_iter(struct bio *bio) 74 { 75 return bio_op(bio) == REQ_OP_DISCARD || 76 bio_op(bio) == REQ_OP_SECURE_ERASE || 77 bio_op(bio) == REQ_OP_WRITE_SAME || 78 bio_op(bio) == REQ_OP_WRITE_ZEROES; 79 } 80 81 static inline bool bio_mergeable(struct bio *bio) 82 { 83 if (bio->bi_opf & REQ_NOMERGE_FLAGS) 84 return false; 85 86 return true; 87 } 88 89 static inline unsigned int bio_cur_bytes(struct bio *bio) 90 { 91 if (bio_has_data(bio)) 92 return bio_iovec(bio).bv_len; 93 else /* dataless requests such as discard */ 94 return bio->bi_iter.bi_size; 95 } 96 97 static inline void *bio_data(struct bio *bio) 98 { 99 if (bio_has_data(bio)) 100 return page_address(bio_page(bio)) + bio_offset(bio); 101 102 return NULL; 103 } 104 105 static inline bool bio_full(struct bio *bio) 106 { 107 return bio->bi_vcnt >= bio->bi_max_vecs; 108 } 109 110 static inline bool bio_next_segment(const struct bio *bio, 111 struct bvec_iter_all *iter) 112 { 113 if (iter->idx >= bio->bi_vcnt) 114 return false; 115 116 bvec_advance(&bio->bi_io_vec[iter->idx], iter); 117 return true; 118 } 119 120 /* 121 * drivers should _never_ use the all version - the bio may have been split 122 * before it got to the driver and the driver won't own all of it 123 */ 124 #define bio_for_each_segment_all(bvl, bio, iter) \ 125 for (bvl = bvec_init_iter_all(&iter); bio_next_segment((bio), &iter); ) 126 127 static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter, 128 unsigned bytes) 129 { 130 iter->bi_sector += bytes >> 9; 131 132 if (bio_no_advance_iter(bio)) 133 iter->bi_size -= bytes; 134 else 135 bvec_iter_advance(bio->bi_io_vec, iter, bytes); 136 /* TODO: It is reasonable to complete bio with error here. */ 137 } 138 139 #define __bio_for_each_segment(bvl, bio, iter, start) \ 140 for (iter = (start); \ 141 (iter).bi_size && \ 142 ((bvl = bio_iter_iovec((bio), (iter))), 1); \ 143 bio_advance_iter((bio), &(iter), (bvl).bv_len)) 144 145 #define bio_for_each_segment(bvl, bio, iter) \ 146 __bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter) 147 148 #define __bio_for_each_bvec(bvl, bio, iter, start) \ 149 for (iter = (start); \ 150 (iter).bi_size && \ 151 ((bvl = mp_bvec_iter_bvec((bio)->bi_io_vec, (iter))), 1); \ 152 bio_advance_iter((bio), &(iter), (bvl).bv_len)) 153 154 /* iterate over multi-page bvec */ 155 #define bio_for_each_bvec(bvl, bio, iter) \ 156 __bio_for_each_bvec(bvl, bio, iter, (bio)->bi_iter) 157 158 #define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len) 159 160 static inline unsigned bio_segments(struct bio *bio) 161 { 162 unsigned segs = 0; 163 struct bio_vec bv; 164 struct bvec_iter iter; 165 166 /* 167 * We special case discard/write same/write zeroes, because they 168 * interpret bi_size differently: 169 */ 170 171 switch (bio_op(bio)) { 172 case REQ_OP_DISCARD: 173 case REQ_OP_SECURE_ERASE: 174 case REQ_OP_WRITE_ZEROES: 175 return 0; 176 case REQ_OP_WRITE_SAME: 177 return 1; 178 default: 179 break; 180 } 181 182 bio_for_each_segment(bv, bio, iter) 183 segs++; 184 185 return segs; 186 } 187 188 /* 189 * get a reference to a bio, so it won't disappear. the intended use is 190 * something like: 191 * 192 * bio_get(bio); 193 * submit_bio(rw, bio); 194 * if (bio->bi_flags ...) 195 * do_something 196 * bio_put(bio); 197 * 198 * without the bio_get(), it could potentially complete I/O before submit_bio 199 * returns. and then bio would be freed memory when if (bio->bi_flags ...) 200 * runs 201 */ 202 static inline void bio_get(struct bio *bio) 203 { 204 bio->bi_flags |= (1 << BIO_REFFED); 205 smp_mb__before_atomic(); 206 atomic_inc(&bio->__bi_cnt); 207 } 208 209 static inline void bio_cnt_set(struct bio *bio, unsigned int count) 210 { 211 if (count != 1) { 212 bio->bi_flags |= (1 << BIO_REFFED); 213 smp_mb__before_atomic(); 214 } 215 atomic_set(&bio->__bi_cnt, count); 216 } 217 218 static inline bool bio_flagged(struct bio *bio, unsigned int bit) 219 { 220 return (bio->bi_flags & (1U << bit)) != 0; 221 } 222 223 static inline void bio_set_flag(struct bio *bio, unsigned int bit) 224 { 225 bio->bi_flags |= (1U << bit); 226 } 227 228 static inline void bio_clear_flag(struct bio *bio, unsigned int bit) 229 { 230 bio->bi_flags &= ~(1U << bit); 231 } 232 233 static inline void bio_get_first_bvec(struct bio *bio, struct bio_vec *bv) 234 { 235 *bv = bio_iovec(bio); 236 } 237 238 static inline void bio_get_last_bvec(struct bio *bio, struct bio_vec *bv) 239 { 240 struct bvec_iter iter = bio->bi_iter; 241 int idx; 242 243 if (unlikely(!bio_multiple_segments(bio))) { 244 *bv = bio_iovec(bio); 245 return; 246 } 247 248 bio_advance_iter(bio, &iter, iter.bi_size); 249 250 if (!iter.bi_bvec_done) 251 idx = iter.bi_idx - 1; 252 else /* in the middle of bvec */ 253 idx = iter.bi_idx; 254 255 *bv = bio->bi_io_vec[idx]; 256 257 /* 258 * iter.bi_bvec_done records actual length of the last bvec 259 * if this bio ends in the middle of one io vector 260 */ 261 if (iter.bi_bvec_done) 262 bv->bv_len = iter.bi_bvec_done; 263 } 264 265 static inline struct bio_vec *bio_first_bvec_all(struct bio *bio) 266 { 267 WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED)); 268 return bio->bi_io_vec; 269 } 270 271 static inline struct page *bio_first_page_all(struct bio *bio) 272 { 273 return bio_first_bvec_all(bio)->bv_page; 274 } 275 276 static inline struct bio_vec *bio_last_bvec_all(struct bio *bio) 277 { 278 WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED)); 279 return &bio->bi_io_vec[bio->bi_vcnt - 1]; 280 } 281 282 enum bip_flags { 283 BIP_BLOCK_INTEGRITY = 1 << 0, /* block layer owns integrity data */ 284 BIP_MAPPED_INTEGRITY = 1 << 1, /* ref tag has been remapped */ 285 BIP_CTRL_NOCHECK = 1 << 2, /* disable HBA integrity checking */ 286 BIP_DISK_NOCHECK = 1 << 3, /* disable disk integrity checking */ 287 BIP_IP_CHECKSUM = 1 << 4, /* IP checksum */ 288 }; 289 290 /* 291 * bio integrity payload 292 */ 293 struct bio_integrity_payload { 294 struct bio *bip_bio; /* parent bio */ 295 296 struct bvec_iter bip_iter; 297 298 unsigned short bip_slab; /* slab the bip came from */ 299 unsigned short bip_vcnt; /* # of integrity bio_vecs */ 300 unsigned short bip_max_vcnt; /* integrity bio_vec slots */ 301 unsigned short bip_flags; /* control flags */ 302 303 struct bvec_iter bio_iter; /* for rewinding parent bio */ 304 305 struct work_struct bip_work; /* I/O completion */ 306 307 struct bio_vec *bip_vec; 308 struct bio_vec bip_inline_vecs[0];/* embedded bvec array */ 309 }; 310 311 #if defined(CONFIG_BLK_DEV_INTEGRITY) 312 313 static inline struct bio_integrity_payload *bio_integrity(struct bio *bio) 314 { 315 if (bio->bi_opf & REQ_INTEGRITY) 316 return bio->bi_integrity; 317 318 return NULL; 319 } 320 321 static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag) 322 { 323 struct bio_integrity_payload *bip = bio_integrity(bio); 324 325 if (bip) 326 return bip->bip_flags & flag; 327 328 return false; 329 } 330 331 static inline sector_t bip_get_seed(struct bio_integrity_payload *bip) 332 { 333 return bip->bip_iter.bi_sector; 334 } 335 336 static inline void bip_set_seed(struct bio_integrity_payload *bip, 337 sector_t seed) 338 { 339 bip->bip_iter.bi_sector = seed; 340 } 341 342 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 343 344 extern void bio_trim(struct bio *bio, int offset, int size); 345 extern struct bio *bio_split(struct bio *bio, int sectors, 346 gfp_t gfp, struct bio_set *bs); 347 348 /** 349 * bio_next_split - get next @sectors from a bio, splitting if necessary 350 * @bio: bio to split 351 * @sectors: number of sectors to split from the front of @bio 352 * @gfp: gfp mask 353 * @bs: bio set to allocate from 354 * 355 * Returns a bio representing the next @sectors of @bio - if the bio is smaller 356 * than @sectors, returns the original bio unchanged. 357 */ 358 static inline struct bio *bio_next_split(struct bio *bio, int sectors, 359 gfp_t gfp, struct bio_set *bs) 360 { 361 if (sectors >= bio_sectors(bio)) 362 return bio; 363 364 return bio_split(bio, sectors, gfp, bs); 365 } 366 367 enum { 368 BIOSET_NEED_BVECS = BIT(0), 369 BIOSET_NEED_RESCUER = BIT(1), 370 }; 371 extern int bioset_init(struct bio_set *, unsigned int, unsigned int, int flags); 372 extern void bioset_exit(struct bio_set *); 373 extern int biovec_init_pool(mempool_t *pool, int pool_entries); 374 extern int bioset_init_from_src(struct bio_set *bs, struct bio_set *src); 375 376 extern struct bio *bio_alloc_bioset(gfp_t, unsigned int, struct bio_set *); 377 extern void bio_put(struct bio *); 378 379 extern void __bio_clone_fast(struct bio *, struct bio *); 380 extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *); 381 382 extern struct bio_set fs_bio_set; 383 384 static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs) 385 { 386 return bio_alloc_bioset(gfp_mask, nr_iovecs, &fs_bio_set); 387 } 388 389 static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs) 390 { 391 return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL); 392 } 393 394 extern blk_qc_t submit_bio(struct bio *); 395 396 extern void bio_endio(struct bio *); 397 398 static inline void bio_io_error(struct bio *bio) 399 { 400 bio->bi_status = BLK_STS_IOERR; 401 bio_endio(bio); 402 } 403 404 static inline void bio_wouldblock_error(struct bio *bio) 405 { 406 bio->bi_status = BLK_STS_AGAIN; 407 bio_endio(bio); 408 } 409 410 struct request_queue; 411 extern int bio_phys_segments(struct request_queue *, struct bio *); 412 413 extern int submit_bio_wait(struct bio *bio); 414 extern void bio_advance(struct bio *, unsigned); 415 416 extern void bio_init(struct bio *bio, struct bio_vec *table, 417 unsigned short max_vecs); 418 extern void bio_uninit(struct bio *); 419 extern void bio_reset(struct bio *); 420 void bio_chain(struct bio *, struct bio *); 421 422 extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int); 423 extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *, 424 unsigned int, unsigned int); 425 bool __bio_try_merge_page(struct bio *bio, struct page *page, 426 unsigned int len, unsigned int off, bool same_page); 427 void __bio_add_page(struct bio *bio, struct page *page, 428 unsigned int len, unsigned int off); 429 int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter); 430 struct rq_map_data; 431 extern struct bio *bio_map_user_iov(struct request_queue *, 432 struct iov_iter *, gfp_t); 433 extern void bio_unmap_user(struct bio *); 434 extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int, 435 gfp_t); 436 extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int, 437 gfp_t, int); 438 extern void bio_set_pages_dirty(struct bio *bio); 439 extern void bio_check_pages_dirty(struct bio *bio); 440 441 void generic_start_io_acct(struct request_queue *q, int op, 442 unsigned long sectors, struct hd_struct *part); 443 void generic_end_io_acct(struct request_queue *q, int op, 444 struct hd_struct *part, 445 unsigned long start_time); 446 447 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 448 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform" 449 #endif 450 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 451 extern void bio_flush_dcache_pages(struct bio *bi); 452 #else 453 static inline void bio_flush_dcache_pages(struct bio *bi) 454 { 455 } 456 #endif 457 458 extern void bio_copy_data_iter(struct bio *dst, struct bvec_iter *dst_iter, 459 struct bio *src, struct bvec_iter *src_iter); 460 extern void bio_copy_data(struct bio *dst, struct bio *src); 461 extern void bio_list_copy_data(struct bio *dst, struct bio *src); 462 extern void bio_free_pages(struct bio *bio); 463 464 extern struct bio *bio_copy_user_iov(struct request_queue *, 465 struct rq_map_data *, 466 struct iov_iter *, 467 gfp_t); 468 extern int bio_uncopy_user(struct bio *); 469 void zero_fill_bio_iter(struct bio *bio, struct bvec_iter iter); 470 471 static inline void zero_fill_bio(struct bio *bio) 472 { 473 zero_fill_bio_iter(bio, bio->bi_iter); 474 } 475 476 extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *); 477 extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int); 478 extern unsigned int bvec_nr_vecs(unsigned short idx); 479 extern const char *bio_devname(struct bio *bio, char *buffer); 480 481 #define bio_set_dev(bio, bdev) \ 482 do { \ 483 if ((bio)->bi_disk != (bdev)->bd_disk) \ 484 bio_clear_flag(bio, BIO_THROTTLED);\ 485 (bio)->bi_disk = (bdev)->bd_disk; \ 486 (bio)->bi_partno = (bdev)->bd_partno; \ 487 bio_associate_blkg(bio); \ 488 } while (0) 489 490 #define bio_copy_dev(dst, src) \ 491 do { \ 492 (dst)->bi_disk = (src)->bi_disk; \ 493 (dst)->bi_partno = (src)->bi_partno; \ 494 bio_clone_blkg_association(dst, src); \ 495 } while (0) 496 497 #define bio_dev(bio) \ 498 disk_devt((bio)->bi_disk) 499 500 #if defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP) 501 void bio_associate_blkg_from_page(struct bio *bio, struct page *page); 502 #else 503 static inline void bio_associate_blkg_from_page(struct bio *bio, 504 struct page *page) { } 505 #endif 506 507 #ifdef CONFIG_BLK_CGROUP 508 void bio_disassociate_blkg(struct bio *bio); 509 void bio_associate_blkg(struct bio *bio); 510 void bio_associate_blkg_from_css(struct bio *bio, 511 struct cgroup_subsys_state *css); 512 void bio_clone_blkg_association(struct bio *dst, struct bio *src); 513 #else /* CONFIG_BLK_CGROUP */ 514 static inline void bio_disassociate_blkg(struct bio *bio) { } 515 static inline void bio_associate_blkg(struct bio *bio) { } 516 static inline void bio_associate_blkg_from_css(struct bio *bio, 517 struct cgroup_subsys_state *css) 518 { } 519 static inline void bio_clone_blkg_association(struct bio *dst, 520 struct bio *src) { } 521 #endif /* CONFIG_BLK_CGROUP */ 522 523 #ifdef CONFIG_HIGHMEM 524 /* 525 * remember never ever reenable interrupts between a bvec_kmap_irq and 526 * bvec_kunmap_irq! 527 */ 528 static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags) 529 { 530 unsigned long addr; 531 532 /* 533 * might not be a highmem page, but the preempt/irq count 534 * balancing is a lot nicer this way 535 */ 536 local_irq_save(*flags); 537 addr = (unsigned long) kmap_atomic(bvec->bv_page); 538 539 BUG_ON(addr & ~PAGE_MASK); 540 541 return (char *) addr + bvec->bv_offset; 542 } 543 544 static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags) 545 { 546 unsigned long ptr = (unsigned long) buffer & PAGE_MASK; 547 548 kunmap_atomic((void *) ptr); 549 local_irq_restore(*flags); 550 } 551 552 #else 553 static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags) 554 { 555 return page_address(bvec->bv_page) + bvec->bv_offset; 556 } 557 558 static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags) 559 { 560 *flags = 0; 561 } 562 #endif 563 564 /* 565 * BIO list management for use by remapping drivers (e.g. DM or MD) and loop. 566 * 567 * A bio_list anchors a singly-linked list of bios chained through the bi_next 568 * member of the bio. The bio_list also caches the last list member to allow 569 * fast access to the tail. 570 */ 571 struct bio_list { 572 struct bio *head; 573 struct bio *tail; 574 }; 575 576 static inline int bio_list_empty(const struct bio_list *bl) 577 { 578 return bl->head == NULL; 579 } 580 581 static inline void bio_list_init(struct bio_list *bl) 582 { 583 bl->head = bl->tail = NULL; 584 } 585 586 #define BIO_EMPTY_LIST { NULL, NULL } 587 588 #define bio_list_for_each(bio, bl) \ 589 for (bio = (bl)->head; bio; bio = bio->bi_next) 590 591 static inline unsigned bio_list_size(const struct bio_list *bl) 592 { 593 unsigned sz = 0; 594 struct bio *bio; 595 596 bio_list_for_each(bio, bl) 597 sz++; 598 599 return sz; 600 } 601 602 static inline void bio_list_add(struct bio_list *bl, struct bio *bio) 603 { 604 bio->bi_next = NULL; 605 606 if (bl->tail) 607 bl->tail->bi_next = bio; 608 else 609 bl->head = bio; 610 611 bl->tail = bio; 612 } 613 614 static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio) 615 { 616 bio->bi_next = bl->head; 617 618 bl->head = bio; 619 620 if (!bl->tail) 621 bl->tail = bio; 622 } 623 624 static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2) 625 { 626 if (!bl2->head) 627 return; 628 629 if (bl->tail) 630 bl->tail->bi_next = bl2->head; 631 else 632 bl->head = bl2->head; 633 634 bl->tail = bl2->tail; 635 } 636 637 static inline void bio_list_merge_head(struct bio_list *bl, 638 struct bio_list *bl2) 639 { 640 if (!bl2->head) 641 return; 642 643 if (bl->head) 644 bl2->tail->bi_next = bl->head; 645 else 646 bl->tail = bl2->tail; 647 648 bl->head = bl2->head; 649 } 650 651 static inline struct bio *bio_list_peek(struct bio_list *bl) 652 { 653 return bl->head; 654 } 655 656 static inline struct bio *bio_list_pop(struct bio_list *bl) 657 { 658 struct bio *bio = bl->head; 659 660 if (bio) { 661 bl->head = bl->head->bi_next; 662 if (!bl->head) 663 bl->tail = NULL; 664 665 bio->bi_next = NULL; 666 } 667 668 return bio; 669 } 670 671 static inline struct bio *bio_list_get(struct bio_list *bl) 672 { 673 struct bio *bio = bl->head; 674 675 bl->head = bl->tail = NULL; 676 677 return bio; 678 } 679 680 /* 681 * Increment chain count for the bio. Make sure the CHAIN flag update 682 * is visible before the raised count. 683 */ 684 static inline void bio_inc_remaining(struct bio *bio) 685 { 686 bio_set_flag(bio, BIO_CHAIN); 687 smp_mb__before_atomic(); 688 atomic_inc(&bio->__bi_remaining); 689 } 690 691 /* 692 * bio_set is used to allow other portions of the IO system to 693 * allocate their own private memory pools for bio and iovec structures. 694 * These memory pools in turn all allocate from the bio_slab 695 * and the bvec_slabs[]. 696 */ 697 #define BIO_POOL_SIZE 2 698 699 struct bio_set { 700 struct kmem_cache *bio_slab; 701 unsigned int front_pad; 702 703 mempool_t bio_pool; 704 mempool_t bvec_pool; 705 #if defined(CONFIG_BLK_DEV_INTEGRITY) 706 mempool_t bio_integrity_pool; 707 mempool_t bvec_integrity_pool; 708 #endif 709 710 /* 711 * Deadlock avoidance for stacking block drivers: see comments in 712 * bio_alloc_bioset() for details 713 */ 714 spinlock_t rescue_lock; 715 struct bio_list rescue_list; 716 struct work_struct rescue_work; 717 struct workqueue_struct *rescue_workqueue; 718 }; 719 720 struct biovec_slab { 721 int nr_vecs; 722 char *name; 723 struct kmem_cache *slab; 724 }; 725 726 static inline bool bioset_initialized(struct bio_set *bs) 727 { 728 return bs->bio_slab != NULL; 729 } 730 731 /* 732 * a small number of entries is fine, not going to be performance critical. 733 * basically we just need to survive 734 */ 735 #define BIO_SPLIT_ENTRIES 2 736 737 #if defined(CONFIG_BLK_DEV_INTEGRITY) 738 739 #define bip_for_each_vec(bvl, bip, iter) \ 740 for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter) 741 742 #define bio_for_each_integrity_vec(_bvl, _bio, _iter) \ 743 for_each_bio(_bio) \ 744 bip_for_each_vec(_bvl, _bio->bi_integrity, _iter) 745 746 extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int); 747 extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int); 748 extern bool bio_integrity_prep(struct bio *); 749 extern void bio_integrity_advance(struct bio *, unsigned int); 750 extern void bio_integrity_trim(struct bio *); 751 extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t); 752 extern int bioset_integrity_create(struct bio_set *, int); 753 extern void bioset_integrity_free(struct bio_set *); 754 extern void bio_integrity_init(void); 755 756 #else /* CONFIG_BLK_DEV_INTEGRITY */ 757 758 static inline void *bio_integrity(struct bio *bio) 759 { 760 return NULL; 761 } 762 763 static inline int bioset_integrity_create(struct bio_set *bs, int pool_size) 764 { 765 return 0; 766 } 767 768 static inline void bioset_integrity_free (struct bio_set *bs) 769 { 770 return; 771 } 772 773 static inline bool bio_integrity_prep(struct bio *bio) 774 { 775 return true; 776 } 777 778 static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src, 779 gfp_t gfp_mask) 780 { 781 return 0; 782 } 783 784 static inline void bio_integrity_advance(struct bio *bio, 785 unsigned int bytes_done) 786 { 787 return; 788 } 789 790 static inline void bio_integrity_trim(struct bio *bio) 791 { 792 return; 793 } 794 795 static inline void bio_integrity_init(void) 796 { 797 return; 798 } 799 800 static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag) 801 { 802 return false; 803 } 804 805 static inline void *bio_integrity_alloc(struct bio * bio, gfp_t gfp, 806 unsigned int nr) 807 { 808 return ERR_PTR(-EINVAL); 809 } 810 811 static inline int bio_integrity_add_page(struct bio *bio, struct page *page, 812 unsigned int len, unsigned int offset) 813 { 814 return 0; 815 } 816 817 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 818 819 /* 820 * Mark a bio as polled. Note that for async polled IO, the caller must 821 * expect -EWOULDBLOCK if we cannot allocate a request (or other resources). 822 * We cannot block waiting for requests on polled IO, as those completions 823 * must be found by the caller. This is different than IRQ driven IO, where 824 * it's safe to wait for IO to complete. 825 */ 826 static inline void bio_set_polled(struct bio *bio, struct kiocb *kiocb) 827 { 828 bio->bi_opf |= REQ_HIPRI; 829 if (!is_sync_kiocb(kiocb)) 830 bio->bi_opf |= REQ_NOWAIT; 831 } 832 833 #endif /* CONFIG_BLOCK */ 834 #endif /* __LINUX_BIO_H */ 835