1 /* 2 * Copyright (C) 2001 Jens Axboe <axboe@suse.de> 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 as 6 * published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public Licens 15 * along with this program; if not, write to the Free Software 16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111- 17 */ 18 #ifndef __LINUX_BIO_H 19 #define __LINUX_BIO_H 20 21 #include <linux/highmem.h> 22 #include <linux/mempool.h> 23 #include <linux/ioprio.h> 24 25 #ifdef CONFIG_BLOCK 26 /* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */ 27 #include <linux/blk_types.h> 28 29 #define BIO_DEBUG 30 31 #ifdef BIO_DEBUG 32 #define BIO_BUG_ON BUG_ON 33 #else 34 #define BIO_BUG_ON 35 #endif 36 37 #ifdef CONFIG_THP_SWAP 38 #if HPAGE_PMD_NR > 256 39 #define BIO_MAX_PAGES HPAGE_PMD_NR 40 #else 41 #define BIO_MAX_PAGES 256 42 #endif 43 #else 44 #define BIO_MAX_PAGES 256 45 #endif 46 47 #define bio_prio(bio) (bio)->bi_ioprio 48 #define bio_set_prio(bio, prio) ((bio)->bi_ioprio = prio) 49 50 #define bio_iter_iovec(bio, iter) \ 51 bvec_iter_bvec((bio)->bi_io_vec, (iter)) 52 53 #define bio_iter_page(bio, iter) \ 54 bvec_iter_page((bio)->bi_io_vec, (iter)) 55 #define bio_iter_len(bio, iter) \ 56 bvec_iter_len((bio)->bi_io_vec, (iter)) 57 #define bio_iter_offset(bio, iter) \ 58 bvec_iter_offset((bio)->bi_io_vec, (iter)) 59 60 #define bio_page(bio) bio_iter_page((bio), (bio)->bi_iter) 61 #define bio_offset(bio) bio_iter_offset((bio), (bio)->bi_iter) 62 #define bio_iovec(bio) bio_iter_iovec((bio), (bio)->bi_iter) 63 64 #define bio_multiple_segments(bio) \ 65 ((bio)->bi_iter.bi_size != bio_iovec(bio).bv_len) 66 67 #define bvec_iter_sectors(iter) ((iter).bi_size >> 9) 68 #define bvec_iter_end_sector(iter) ((iter).bi_sector + bvec_iter_sectors((iter))) 69 70 #define bio_sectors(bio) bvec_iter_sectors((bio)->bi_iter) 71 #define bio_end_sector(bio) bvec_iter_end_sector((bio)->bi_iter) 72 73 /* 74 * Return the data direction, READ or WRITE. 75 */ 76 #define bio_data_dir(bio) \ 77 (op_is_write(bio_op(bio)) ? WRITE : READ) 78 79 /* 80 * Check whether this bio carries any data or not. A NULL bio is allowed. 81 */ 82 static inline bool bio_has_data(struct bio *bio) 83 { 84 if (bio && 85 bio->bi_iter.bi_size && 86 bio_op(bio) != REQ_OP_DISCARD && 87 bio_op(bio) != REQ_OP_SECURE_ERASE && 88 bio_op(bio) != REQ_OP_WRITE_ZEROES) 89 return true; 90 91 return false; 92 } 93 94 static inline bool bio_no_advance_iter(struct bio *bio) 95 { 96 return bio_op(bio) == REQ_OP_DISCARD || 97 bio_op(bio) == REQ_OP_SECURE_ERASE || 98 bio_op(bio) == REQ_OP_WRITE_SAME || 99 bio_op(bio) == REQ_OP_WRITE_ZEROES; 100 } 101 102 static inline bool bio_mergeable(struct bio *bio) 103 { 104 if (bio->bi_opf & REQ_NOMERGE_FLAGS) 105 return false; 106 107 return true; 108 } 109 110 static inline unsigned int bio_cur_bytes(struct bio *bio) 111 { 112 if (bio_has_data(bio)) 113 return bio_iovec(bio).bv_len; 114 else /* dataless requests such as discard */ 115 return bio->bi_iter.bi_size; 116 } 117 118 static inline void *bio_data(struct bio *bio) 119 { 120 if (bio_has_data(bio)) 121 return page_address(bio_page(bio)) + bio_offset(bio); 122 123 return NULL; 124 } 125 126 static inline bool bio_full(struct bio *bio) 127 { 128 return bio->bi_vcnt >= bio->bi_max_vecs; 129 } 130 131 /* 132 * drivers should _never_ use the all version - the bio may have been split 133 * before it got to the driver and the driver won't own all of it 134 */ 135 #define bio_for_each_segment_all(bvl, bio, i) \ 136 for (i = 0, bvl = (bio)->bi_io_vec; i < (bio)->bi_vcnt; i++, bvl++) 137 138 static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter, 139 unsigned bytes) 140 { 141 iter->bi_sector += bytes >> 9; 142 143 if (bio_no_advance_iter(bio)) 144 iter->bi_size -= bytes; 145 else 146 bvec_iter_advance(bio->bi_io_vec, iter, bytes); 147 /* TODO: It is reasonable to complete bio with error here. */ 148 } 149 150 #define __bio_for_each_segment(bvl, bio, iter, start) \ 151 for (iter = (start); \ 152 (iter).bi_size && \ 153 ((bvl = bio_iter_iovec((bio), (iter))), 1); \ 154 bio_advance_iter((bio), &(iter), (bvl).bv_len)) 155 156 #define bio_for_each_segment(bvl, bio, iter) \ 157 __bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter) 158 159 #define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len) 160 161 static inline unsigned bio_segments(struct bio *bio) 162 { 163 unsigned segs = 0; 164 struct bio_vec bv; 165 struct bvec_iter iter; 166 167 /* 168 * We special case discard/write same/write zeroes, because they 169 * interpret bi_size differently: 170 */ 171 172 switch (bio_op(bio)) { 173 case REQ_OP_DISCARD: 174 case REQ_OP_SECURE_ERASE: 175 case REQ_OP_WRITE_ZEROES: 176 return 0; 177 case REQ_OP_WRITE_SAME: 178 return 1; 179 default: 180 break; 181 } 182 183 bio_for_each_segment(bv, bio, iter) 184 segs++; 185 186 return segs; 187 } 188 189 /* 190 * get a reference to a bio, so it won't disappear. the intended use is 191 * something like: 192 * 193 * bio_get(bio); 194 * submit_bio(rw, bio); 195 * if (bio->bi_flags ...) 196 * do_something 197 * bio_put(bio); 198 * 199 * without the bio_get(), it could potentially complete I/O before submit_bio 200 * returns. and then bio would be freed memory when if (bio->bi_flags ...) 201 * runs 202 */ 203 static inline void bio_get(struct bio *bio) 204 { 205 bio->bi_flags |= (1 << BIO_REFFED); 206 smp_mb__before_atomic(); 207 atomic_inc(&bio->__bi_cnt); 208 } 209 210 static inline void bio_cnt_set(struct bio *bio, unsigned int count) 211 { 212 if (count != 1) { 213 bio->bi_flags |= (1 << BIO_REFFED); 214 smp_mb__before_atomic(); 215 } 216 atomic_set(&bio->__bi_cnt, count); 217 } 218 219 static inline bool bio_flagged(struct bio *bio, unsigned int bit) 220 { 221 return (bio->bi_flags & (1U << bit)) != 0; 222 } 223 224 static inline void bio_set_flag(struct bio *bio, unsigned int bit) 225 { 226 bio->bi_flags |= (1U << bit); 227 } 228 229 static inline void bio_clear_flag(struct bio *bio, unsigned int bit) 230 { 231 bio->bi_flags &= ~(1U << bit); 232 } 233 234 static inline void bio_get_first_bvec(struct bio *bio, struct bio_vec *bv) 235 { 236 *bv = bio_iovec(bio); 237 } 238 239 static inline void bio_get_last_bvec(struct bio *bio, struct bio_vec *bv) 240 { 241 struct bvec_iter iter = bio->bi_iter; 242 int idx; 243 244 if (unlikely(!bio_multiple_segments(bio))) { 245 *bv = bio_iovec(bio); 246 return; 247 } 248 249 bio_advance_iter(bio, &iter, iter.bi_size); 250 251 if (!iter.bi_bvec_done) 252 idx = iter.bi_idx - 1; 253 else /* in the middle of bvec */ 254 idx = iter.bi_idx; 255 256 *bv = bio->bi_io_vec[idx]; 257 258 /* 259 * iter.bi_bvec_done records actual length of the last bvec 260 * if this bio ends in the middle of one io vector 261 */ 262 if (iter.bi_bvec_done) 263 bv->bv_len = iter.bi_bvec_done; 264 } 265 266 static inline unsigned bio_pages_all(struct bio *bio) 267 { 268 WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED)); 269 return bio->bi_vcnt; 270 } 271 272 static inline struct bio_vec *bio_first_bvec_all(struct bio *bio) 273 { 274 WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED)); 275 return bio->bi_io_vec; 276 } 277 278 static inline struct page *bio_first_page_all(struct bio *bio) 279 { 280 return bio_first_bvec_all(bio)->bv_page; 281 } 282 283 static inline struct bio_vec *bio_last_bvec_all(struct bio *bio) 284 { 285 WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED)); 286 return &bio->bi_io_vec[bio->bi_vcnt - 1]; 287 } 288 289 enum bip_flags { 290 BIP_BLOCK_INTEGRITY = 1 << 0, /* block layer owns integrity data */ 291 BIP_MAPPED_INTEGRITY = 1 << 1, /* ref tag has been remapped */ 292 BIP_CTRL_NOCHECK = 1 << 2, /* disable HBA integrity checking */ 293 BIP_DISK_NOCHECK = 1 << 3, /* disable disk integrity checking */ 294 BIP_IP_CHECKSUM = 1 << 4, /* IP checksum */ 295 }; 296 297 /* 298 * bio integrity payload 299 */ 300 struct bio_integrity_payload { 301 struct bio *bip_bio; /* parent bio */ 302 303 struct bvec_iter bip_iter; 304 305 unsigned short bip_slab; /* slab the bip came from */ 306 unsigned short bip_vcnt; /* # of integrity bio_vecs */ 307 unsigned short bip_max_vcnt; /* integrity bio_vec slots */ 308 unsigned short bip_flags; /* control flags */ 309 310 struct bvec_iter bio_iter; /* for rewinding parent bio */ 311 312 struct work_struct bip_work; /* I/O completion */ 313 314 struct bio_vec *bip_vec; 315 struct bio_vec bip_inline_vecs[0];/* embedded bvec array */ 316 }; 317 318 #if defined(CONFIG_BLK_DEV_INTEGRITY) 319 320 static inline struct bio_integrity_payload *bio_integrity(struct bio *bio) 321 { 322 if (bio->bi_opf & REQ_INTEGRITY) 323 return bio->bi_integrity; 324 325 return NULL; 326 } 327 328 static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag) 329 { 330 struct bio_integrity_payload *bip = bio_integrity(bio); 331 332 if (bip) 333 return bip->bip_flags & flag; 334 335 return false; 336 } 337 338 static inline sector_t bip_get_seed(struct bio_integrity_payload *bip) 339 { 340 return bip->bip_iter.bi_sector; 341 } 342 343 static inline void bip_set_seed(struct bio_integrity_payload *bip, 344 sector_t seed) 345 { 346 bip->bip_iter.bi_sector = seed; 347 } 348 349 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 350 351 extern void bio_trim(struct bio *bio, int offset, int size); 352 extern struct bio *bio_split(struct bio *bio, int sectors, 353 gfp_t gfp, struct bio_set *bs); 354 355 /** 356 * bio_next_split - get next @sectors from a bio, splitting if necessary 357 * @bio: bio to split 358 * @sectors: number of sectors to split from the front of @bio 359 * @gfp: gfp mask 360 * @bs: bio set to allocate from 361 * 362 * Returns a bio representing the next @sectors of @bio - if the bio is smaller 363 * than @sectors, returns the original bio unchanged. 364 */ 365 static inline struct bio *bio_next_split(struct bio *bio, int sectors, 366 gfp_t gfp, struct bio_set *bs) 367 { 368 if (sectors >= bio_sectors(bio)) 369 return bio; 370 371 return bio_split(bio, sectors, gfp, bs); 372 } 373 374 enum { 375 BIOSET_NEED_BVECS = BIT(0), 376 BIOSET_NEED_RESCUER = BIT(1), 377 }; 378 extern int bioset_init(struct bio_set *, unsigned int, unsigned int, int flags); 379 extern void bioset_exit(struct bio_set *); 380 extern int biovec_init_pool(mempool_t *pool, int pool_entries); 381 extern int bioset_init_from_src(struct bio_set *bs, struct bio_set *src); 382 383 extern struct bio *bio_alloc_bioset(gfp_t, unsigned int, struct bio_set *); 384 extern void bio_put(struct bio *); 385 386 extern void __bio_clone_fast(struct bio *, struct bio *); 387 extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *); 388 389 extern struct bio_set fs_bio_set; 390 391 static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs) 392 { 393 return bio_alloc_bioset(gfp_mask, nr_iovecs, &fs_bio_set); 394 } 395 396 static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs) 397 { 398 return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL); 399 } 400 401 extern blk_qc_t submit_bio(struct bio *); 402 403 extern void bio_endio(struct bio *); 404 405 static inline void bio_io_error(struct bio *bio) 406 { 407 bio->bi_status = BLK_STS_IOERR; 408 bio_endio(bio); 409 } 410 411 static inline void bio_wouldblock_error(struct bio *bio) 412 { 413 bio->bi_status = BLK_STS_AGAIN; 414 bio_endio(bio); 415 } 416 417 struct request_queue; 418 extern int bio_phys_segments(struct request_queue *, struct bio *); 419 420 extern int submit_bio_wait(struct bio *bio); 421 extern void bio_advance(struct bio *, unsigned); 422 423 extern void bio_init(struct bio *bio, struct bio_vec *table, 424 unsigned short max_vecs); 425 extern void bio_uninit(struct bio *); 426 extern void bio_reset(struct bio *); 427 void bio_chain(struct bio *, struct bio *); 428 429 extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int); 430 extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *, 431 unsigned int, unsigned int); 432 bool __bio_try_merge_page(struct bio *bio, struct page *page, 433 unsigned int len, unsigned int off); 434 void __bio_add_page(struct bio *bio, struct page *page, 435 unsigned int len, unsigned int off); 436 int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter); 437 struct rq_map_data; 438 extern struct bio *bio_map_user_iov(struct request_queue *, 439 struct iov_iter *, gfp_t); 440 extern void bio_unmap_user(struct bio *); 441 extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int, 442 gfp_t); 443 extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int, 444 gfp_t, int); 445 extern void bio_set_pages_dirty(struct bio *bio); 446 extern void bio_check_pages_dirty(struct bio *bio); 447 448 void generic_start_io_acct(struct request_queue *q, int op, 449 unsigned long sectors, struct hd_struct *part); 450 void generic_end_io_acct(struct request_queue *q, int op, 451 struct hd_struct *part, 452 unsigned long start_time); 453 454 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 455 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform" 456 #endif 457 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 458 extern void bio_flush_dcache_pages(struct bio *bi); 459 #else 460 static inline void bio_flush_dcache_pages(struct bio *bi) 461 { 462 } 463 #endif 464 465 extern void bio_copy_data_iter(struct bio *dst, struct bvec_iter *dst_iter, 466 struct bio *src, struct bvec_iter *src_iter); 467 extern void bio_copy_data(struct bio *dst, struct bio *src); 468 extern void bio_list_copy_data(struct bio *dst, struct bio *src); 469 extern void bio_free_pages(struct bio *bio); 470 471 extern struct bio *bio_copy_user_iov(struct request_queue *, 472 struct rq_map_data *, 473 struct iov_iter *, 474 gfp_t); 475 extern int bio_uncopy_user(struct bio *); 476 void zero_fill_bio_iter(struct bio *bio, struct bvec_iter iter); 477 478 static inline void zero_fill_bio(struct bio *bio) 479 { 480 zero_fill_bio_iter(bio, bio->bi_iter); 481 } 482 483 extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *); 484 extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int); 485 extern unsigned int bvec_nr_vecs(unsigned short idx); 486 extern const char *bio_devname(struct bio *bio, char *buffer); 487 488 #define bio_set_dev(bio, bdev) \ 489 do { \ 490 if ((bio)->bi_disk != (bdev)->bd_disk) \ 491 bio_clear_flag(bio, BIO_THROTTLED);\ 492 (bio)->bi_disk = (bdev)->bd_disk; \ 493 (bio)->bi_partno = (bdev)->bd_partno; \ 494 bio_associate_blkg(bio); \ 495 } while (0) 496 497 #define bio_copy_dev(dst, src) \ 498 do { \ 499 (dst)->bi_disk = (src)->bi_disk; \ 500 (dst)->bi_partno = (src)->bi_partno; \ 501 bio_clone_blkg_association(dst, src); \ 502 } while (0) 503 504 #define bio_dev(bio) \ 505 disk_devt((bio)->bi_disk) 506 507 #if defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP) 508 void bio_associate_blkg_from_page(struct bio *bio, struct page *page); 509 #else 510 static inline void bio_associate_blkg_from_page(struct bio *bio, 511 struct page *page) { } 512 #endif 513 514 #ifdef CONFIG_BLK_CGROUP 515 void bio_disassociate_blkg(struct bio *bio); 516 void bio_associate_blkg(struct bio *bio); 517 void bio_associate_blkg_from_css(struct bio *bio, 518 struct cgroup_subsys_state *css); 519 void bio_clone_blkg_association(struct bio *dst, struct bio *src); 520 #else /* CONFIG_BLK_CGROUP */ 521 static inline void bio_disassociate_blkg(struct bio *bio) { } 522 static inline void bio_associate_blkg(struct bio *bio) { } 523 static inline void bio_associate_blkg_from_css(struct bio *bio, 524 struct cgroup_subsys_state *css) 525 { } 526 static inline void bio_clone_blkg_association(struct bio *dst, 527 struct bio *src) { } 528 #endif /* CONFIG_BLK_CGROUP */ 529 530 #ifdef CONFIG_HIGHMEM 531 /* 532 * remember never ever reenable interrupts between a bvec_kmap_irq and 533 * bvec_kunmap_irq! 534 */ 535 static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags) 536 { 537 unsigned long addr; 538 539 /* 540 * might not be a highmem page, but the preempt/irq count 541 * balancing is a lot nicer this way 542 */ 543 local_irq_save(*flags); 544 addr = (unsigned long) kmap_atomic(bvec->bv_page); 545 546 BUG_ON(addr & ~PAGE_MASK); 547 548 return (char *) addr + bvec->bv_offset; 549 } 550 551 static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags) 552 { 553 unsigned long ptr = (unsigned long) buffer & PAGE_MASK; 554 555 kunmap_atomic((void *) ptr); 556 local_irq_restore(*flags); 557 } 558 559 #else 560 static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags) 561 { 562 return page_address(bvec->bv_page) + bvec->bv_offset; 563 } 564 565 static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags) 566 { 567 *flags = 0; 568 } 569 #endif 570 571 /* 572 * BIO list management for use by remapping drivers (e.g. DM or MD) and loop. 573 * 574 * A bio_list anchors a singly-linked list of bios chained through the bi_next 575 * member of the bio. The bio_list also caches the last list member to allow 576 * fast access to the tail. 577 */ 578 struct bio_list { 579 struct bio *head; 580 struct bio *tail; 581 }; 582 583 static inline int bio_list_empty(const struct bio_list *bl) 584 { 585 return bl->head == NULL; 586 } 587 588 static inline void bio_list_init(struct bio_list *bl) 589 { 590 bl->head = bl->tail = NULL; 591 } 592 593 #define BIO_EMPTY_LIST { NULL, NULL } 594 595 #define bio_list_for_each(bio, bl) \ 596 for (bio = (bl)->head; bio; bio = bio->bi_next) 597 598 static inline unsigned bio_list_size(const struct bio_list *bl) 599 { 600 unsigned sz = 0; 601 struct bio *bio; 602 603 bio_list_for_each(bio, bl) 604 sz++; 605 606 return sz; 607 } 608 609 static inline void bio_list_add(struct bio_list *bl, struct bio *bio) 610 { 611 bio->bi_next = NULL; 612 613 if (bl->tail) 614 bl->tail->bi_next = bio; 615 else 616 bl->head = bio; 617 618 bl->tail = bio; 619 } 620 621 static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio) 622 { 623 bio->bi_next = bl->head; 624 625 bl->head = bio; 626 627 if (!bl->tail) 628 bl->tail = bio; 629 } 630 631 static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2) 632 { 633 if (!bl2->head) 634 return; 635 636 if (bl->tail) 637 bl->tail->bi_next = bl2->head; 638 else 639 bl->head = bl2->head; 640 641 bl->tail = bl2->tail; 642 } 643 644 static inline void bio_list_merge_head(struct bio_list *bl, 645 struct bio_list *bl2) 646 { 647 if (!bl2->head) 648 return; 649 650 if (bl->head) 651 bl2->tail->bi_next = bl->head; 652 else 653 bl->tail = bl2->tail; 654 655 bl->head = bl2->head; 656 } 657 658 static inline struct bio *bio_list_peek(struct bio_list *bl) 659 { 660 return bl->head; 661 } 662 663 static inline struct bio *bio_list_pop(struct bio_list *bl) 664 { 665 struct bio *bio = bl->head; 666 667 if (bio) { 668 bl->head = bl->head->bi_next; 669 if (!bl->head) 670 bl->tail = NULL; 671 672 bio->bi_next = NULL; 673 } 674 675 return bio; 676 } 677 678 static inline struct bio *bio_list_get(struct bio_list *bl) 679 { 680 struct bio *bio = bl->head; 681 682 bl->head = bl->tail = NULL; 683 684 return bio; 685 } 686 687 /* 688 * Increment chain count for the bio. Make sure the CHAIN flag update 689 * is visible before the raised count. 690 */ 691 static inline void bio_inc_remaining(struct bio *bio) 692 { 693 bio_set_flag(bio, BIO_CHAIN); 694 smp_mb__before_atomic(); 695 atomic_inc(&bio->__bi_remaining); 696 } 697 698 /* 699 * bio_set is used to allow other portions of the IO system to 700 * allocate their own private memory pools for bio and iovec structures. 701 * These memory pools in turn all allocate from the bio_slab 702 * and the bvec_slabs[]. 703 */ 704 #define BIO_POOL_SIZE 2 705 706 struct bio_set { 707 struct kmem_cache *bio_slab; 708 unsigned int front_pad; 709 710 mempool_t bio_pool; 711 mempool_t bvec_pool; 712 #if defined(CONFIG_BLK_DEV_INTEGRITY) 713 mempool_t bio_integrity_pool; 714 mempool_t bvec_integrity_pool; 715 #endif 716 717 /* 718 * Deadlock avoidance for stacking block drivers: see comments in 719 * bio_alloc_bioset() for details 720 */ 721 spinlock_t rescue_lock; 722 struct bio_list rescue_list; 723 struct work_struct rescue_work; 724 struct workqueue_struct *rescue_workqueue; 725 }; 726 727 struct biovec_slab { 728 int nr_vecs; 729 char *name; 730 struct kmem_cache *slab; 731 }; 732 733 static inline bool bioset_initialized(struct bio_set *bs) 734 { 735 return bs->bio_slab != NULL; 736 } 737 738 /* 739 * a small number of entries is fine, not going to be performance critical. 740 * basically we just need to survive 741 */ 742 #define BIO_SPLIT_ENTRIES 2 743 744 #if defined(CONFIG_BLK_DEV_INTEGRITY) 745 746 #define bip_for_each_vec(bvl, bip, iter) \ 747 for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter) 748 749 #define bio_for_each_integrity_vec(_bvl, _bio, _iter) \ 750 for_each_bio(_bio) \ 751 bip_for_each_vec(_bvl, _bio->bi_integrity, _iter) 752 753 extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int); 754 extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int); 755 extern bool bio_integrity_prep(struct bio *); 756 extern void bio_integrity_advance(struct bio *, unsigned int); 757 extern void bio_integrity_trim(struct bio *); 758 extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t); 759 extern int bioset_integrity_create(struct bio_set *, int); 760 extern void bioset_integrity_free(struct bio_set *); 761 extern void bio_integrity_init(void); 762 763 #else /* CONFIG_BLK_DEV_INTEGRITY */ 764 765 static inline void *bio_integrity(struct bio *bio) 766 { 767 return NULL; 768 } 769 770 static inline int bioset_integrity_create(struct bio_set *bs, int pool_size) 771 { 772 return 0; 773 } 774 775 static inline void bioset_integrity_free (struct bio_set *bs) 776 { 777 return; 778 } 779 780 static inline bool bio_integrity_prep(struct bio *bio) 781 { 782 return true; 783 } 784 785 static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src, 786 gfp_t gfp_mask) 787 { 788 return 0; 789 } 790 791 static inline void bio_integrity_advance(struct bio *bio, 792 unsigned int bytes_done) 793 { 794 return; 795 } 796 797 static inline void bio_integrity_trim(struct bio *bio) 798 { 799 return; 800 } 801 802 static inline void bio_integrity_init(void) 803 { 804 return; 805 } 806 807 static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag) 808 { 809 return false; 810 } 811 812 static inline void *bio_integrity_alloc(struct bio * bio, gfp_t gfp, 813 unsigned int nr) 814 { 815 return ERR_PTR(-EINVAL); 816 } 817 818 static inline int bio_integrity_add_page(struct bio *bio, struct page *page, 819 unsigned int len, unsigned int offset) 820 { 821 return 0; 822 } 823 824 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 825 826 #endif /* CONFIG_BLOCK */ 827 #endif /* __LINUX_BIO_H */ 828