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 23 #include <linux/highmem.h> 24 #include <linux/mempool.h> 25 #include <linux/ioprio.h> 26 #include <linux/bug.h> 27 28 #ifdef CONFIG_BLOCK 29 30 #include <asm/io.h> 31 32 /* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */ 33 #include <linux/blk_types.h> 34 35 #define BIO_DEBUG 36 37 #ifdef BIO_DEBUG 38 #define BIO_BUG_ON BUG_ON 39 #else 40 #define BIO_BUG_ON 41 #endif 42 43 #define BIO_MAX_PAGES 256 44 #define BIO_MAX_SIZE (BIO_MAX_PAGES << PAGE_CACHE_SHIFT) 45 #define BIO_MAX_SECTORS (BIO_MAX_SIZE >> 9) 46 47 /* 48 * upper 16 bits of bi_rw define the io priority of this bio 49 */ 50 #define BIO_PRIO_SHIFT (8 * sizeof(unsigned long) - IOPRIO_BITS) 51 #define bio_prio(bio) ((bio)->bi_rw >> BIO_PRIO_SHIFT) 52 #define bio_prio_valid(bio) ioprio_valid(bio_prio(bio)) 53 54 #define bio_set_prio(bio, prio) do { \ 55 WARN_ON(prio >= (1 << IOPRIO_BITS)); \ 56 (bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1); \ 57 (bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT); \ 58 } while (0) 59 60 /* 61 * various member access, note that bio_data should of course not be used 62 * on highmem page vectors 63 */ 64 #define __bvec_iter_bvec(bvec, iter) (&(bvec)[(iter).bi_idx]) 65 66 #define bvec_iter_page(bvec, iter) \ 67 (__bvec_iter_bvec((bvec), (iter))->bv_page) 68 69 #define bvec_iter_len(bvec, iter) \ 70 min((iter).bi_size, \ 71 __bvec_iter_bvec((bvec), (iter))->bv_len - (iter).bi_bvec_done) 72 73 #define bvec_iter_offset(bvec, iter) \ 74 (__bvec_iter_bvec((bvec), (iter))->bv_offset + (iter).bi_bvec_done) 75 76 #define bvec_iter_bvec(bvec, iter) \ 77 ((struct bio_vec) { \ 78 .bv_page = bvec_iter_page((bvec), (iter)), \ 79 .bv_len = bvec_iter_len((bvec), (iter)), \ 80 .bv_offset = bvec_iter_offset((bvec), (iter)), \ 81 }) 82 83 #define bio_iter_iovec(bio, iter) \ 84 bvec_iter_bvec((bio)->bi_io_vec, (iter)) 85 86 #define bio_iter_page(bio, iter) \ 87 bvec_iter_page((bio)->bi_io_vec, (iter)) 88 #define bio_iter_len(bio, iter) \ 89 bvec_iter_len((bio)->bi_io_vec, (iter)) 90 #define bio_iter_offset(bio, iter) \ 91 bvec_iter_offset((bio)->bi_io_vec, (iter)) 92 93 #define bio_page(bio) bio_iter_page((bio), (bio)->bi_iter) 94 #define bio_offset(bio) bio_iter_offset((bio), (bio)->bi_iter) 95 #define bio_iovec(bio) bio_iter_iovec((bio), (bio)->bi_iter) 96 97 #define bio_multiple_segments(bio) \ 98 ((bio)->bi_iter.bi_size != bio_iovec(bio).bv_len) 99 #define bio_sectors(bio) ((bio)->bi_iter.bi_size >> 9) 100 #define bio_end_sector(bio) ((bio)->bi_iter.bi_sector + bio_sectors((bio))) 101 102 /* 103 * Check whether this bio carries any data or not. A NULL bio is allowed. 104 */ 105 static inline bool bio_has_data(struct bio *bio) 106 { 107 if (bio && 108 bio->bi_iter.bi_size && 109 !(bio->bi_rw & REQ_DISCARD)) 110 return true; 111 112 return false; 113 } 114 115 static inline bool bio_is_rw(struct bio *bio) 116 { 117 if (!bio_has_data(bio)) 118 return false; 119 120 if (bio->bi_rw & BIO_NO_ADVANCE_ITER_MASK) 121 return false; 122 123 return true; 124 } 125 126 static inline bool bio_mergeable(struct bio *bio) 127 { 128 if (bio->bi_rw & REQ_NOMERGE_FLAGS) 129 return false; 130 131 return true; 132 } 133 134 static inline unsigned int bio_cur_bytes(struct bio *bio) 135 { 136 if (bio_has_data(bio)) 137 return bio_iovec(bio).bv_len; 138 else /* dataless requests such as discard */ 139 return bio->bi_iter.bi_size; 140 } 141 142 static inline void *bio_data(struct bio *bio) 143 { 144 if (bio_has_data(bio)) 145 return page_address(bio_page(bio)) + bio_offset(bio); 146 147 return NULL; 148 } 149 150 /* 151 * will die 152 */ 153 #define bio_to_phys(bio) (page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio))) 154 #define bvec_to_phys(bv) (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset) 155 156 /* 157 * queues that have highmem support enabled may still need to revert to 158 * PIO transfers occasionally and thus map high pages temporarily. For 159 * permanent PIO fall back, user is probably better off disabling highmem 160 * I/O completely on that queue (see ide-dma for example) 161 */ 162 #define __bio_kmap_atomic(bio, iter) \ 163 (kmap_atomic(bio_iter_iovec((bio), (iter)).bv_page) + \ 164 bio_iter_iovec((bio), (iter)).bv_offset) 165 166 #define __bio_kunmap_atomic(addr) kunmap_atomic(addr) 167 168 /* 169 * merge helpers etc 170 */ 171 172 /* Default implementation of BIOVEC_PHYS_MERGEABLE */ 173 #define __BIOVEC_PHYS_MERGEABLE(vec1, vec2) \ 174 ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2))) 175 176 /* 177 * allow arch override, for eg virtualized architectures (put in asm/io.h) 178 */ 179 #ifndef BIOVEC_PHYS_MERGEABLE 180 #define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \ 181 __BIOVEC_PHYS_MERGEABLE(vec1, vec2) 182 #endif 183 184 #define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \ 185 (((addr1) | (mask)) == (((addr2) - 1) | (mask))) 186 #define BIOVEC_SEG_BOUNDARY(q, b1, b2) \ 187 __BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q))) 188 189 /* 190 * drivers should _never_ use the all version - the bio may have been split 191 * before it got to the driver and the driver won't own all of it 192 */ 193 #define bio_for_each_segment_all(bvl, bio, i) \ 194 for (i = 0, bvl = (bio)->bi_io_vec; i < (bio)->bi_vcnt; i++, bvl++) 195 196 static inline void bvec_iter_advance(struct bio_vec *bv, struct bvec_iter *iter, 197 unsigned bytes) 198 { 199 WARN_ONCE(bytes > iter->bi_size, 200 "Attempted to advance past end of bvec iter\n"); 201 202 while (bytes) { 203 unsigned len = min(bytes, bvec_iter_len(bv, *iter)); 204 205 bytes -= len; 206 iter->bi_size -= len; 207 iter->bi_bvec_done += len; 208 209 if (iter->bi_bvec_done == __bvec_iter_bvec(bv, *iter)->bv_len) { 210 iter->bi_bvec_done = 0; 211 iter->bi_idx++; 212 } 213 } 214 } 215 216 #define for_each_bvec(bvl, bio_vec, iter, start) \ 217 for (iter = (start); \ 218 (iter).bi_size && \ 219 ((bvl = bvec_iter_bvec((bio_vec), (iter))), 1); \ 220 bvec_iter_advance((bio_vec), &(iter), (bvl).bv_len)) 221 222 223 static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter, 224 unsigned bytes) 225 { 226 iter->bi_sector += bytes >> 9; 227 228 if (bio->bi_rw & BIO_NO_ADVANCE_ITER_MASK) 229 iter->bi_size -= bytes; 230 else 231 bvec_iter_advance(bio->bi_io_vec, iter, bytes); 232 } 233 234 #define __bio_for_each_segment(bvl, bio, iter, start) \ 235 for (iter = (start); \ 236 (iter).bi_size && \ 237 ((bvl = bio_iter_iovec((bio), (iter))), 1); \ 238 bio_advance_iter((bio), &(iter), (bvl).bv_len)) 239 240 #define bio_for_each_segment(bvl, bio, iter) \ 241 __bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter) 242 243 #define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len) 244 245 static inline unsigned bio_segments(struct bio *bio) 246 { 247 unsigned segs = 0; 248 struct bio_vec bv; 249 struct bvec_iter iter; 250 251 /* 252 * We special case discard/write same, because they interpret bi_size 253 * differently: 254 */ 255 256 if (bio->bi_rw & REQ_DISCARD) 257 return 1; 258 259 if (bio->bi_rw & REQ_WRITE_SAME) 260 return 1; 261 262 bio_for_each_segment(bv, bio, iter) 263 segs++; 264 265 return segs; 266 } 267 268 /* 269 * get a reference to a bio, so it won't disappear. the intended use is 270 * something like: 271 * 272 * bio_get(bio); 273 * submit_bio(rw, bio); 274 * if (bio->bi_flags ...) 275 * do_something 276 * bio_put(bio); 277 * 278 * without the bio_get(), it could potentially complete I/O before submit_bio 279 * returns. and then bio would be freed memory when if (bio->bi_flags ...) 280 * runs 281 */ 282 static inline void bio_get(struct bio *bio) 283 { 284 bio->bi_flags |= (1 << BIO_REFFED); 285 smp_mb__before_atomic(); 286 atomic_inc(&bio->__bi_cnt); 287 } 288 289 static inline void bio_cnt_set(struct bio *bio, unsigned int count) 290 { 291 if (count != 1) { 292 bio->bi_flags |= (1 << BIO_REFFED); 293 smp_mb__before_atomic(); 294 } 295 atomic_set(&bio->__bi_cnt, count); 296 } 297 298 static inline bool bio_flagged(struct bio *bio, unsigned int bit) 299 { 300 return (bio->bi_flags & (1U << bit)) != 0; 301 } 302 303 static inline void bio_set_flag(struct bio *bio, unsigned int bit) 304 { 305 bio->bi_flags |= (1U << bit); 306 } 307 308 static inline void bio_clear_flag(struct bio *bio, unsigned int bit) 309 { 310 bio->bi_flags &= ~(1U << bit); 311 } 312 313 enum bip_flags { 314 BIP_BLOCK_INTEGRITY = 1 << 0, /* block layer owns integrity data */ 315 BIP_MAPPED_INTEGRITY = 1 << 1, /* ref tag has been remapped */ 316 BIP_CTRL_NOCHECK = 1 << 2, /* disable HBA integrity checking */ 317 BIP_DISK_NOCHECK = 1 << 3, /* disable disk integrity checking */ 318 BIP_IP_CHECKSUM = 1 << 4, /* IP checksum */ 319 }; 320 321 /* 322 * bio integrity payload 323 */ 324 struct bio_integrity_payload { 325 struct bio *bip_bio; /* parent bio */ 326 327 struct bvec_iter bip_iter; 328 329 bio_end_io_t *bip_end_io; /* saved I/O completion fn */ 330 331 unsigned short bip_slab; /* slab the bip came from */ 332 unsigned short bip_vcnt; /* # of integrity bio_vecs */ 333 unsigned short bip_max_vcnt; /* integrity bio_vec slots */ 334 unsigned short bip_flags; /* control flags */ 335 336 struct work_struct bip_work; /* I/O completion */ 337 338 struct bio_vec *bip_vec; 339 struct bio_vec bip_inline_vecs[0];/* embedded bvec array */ 340 }; 341 342 #if defined(CONFIG_BLK_DEV_INTEGRITY) 343 344 static inline struct bio_integrity_payload *bio_integrity(struct bio *bio) 345 { 346 if (bio->bi_rw & REQ_INTEGRITY) 347 return bio->bi_integrity; 348 349 return NULL; 350 } 351 352 static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag) 353 { 354 struct bio_integrity_payload *bip = bio_integrity(bio); 355 356 if (bip) 357 return bip->bip_flags & flag; 358 359 return false; 360 } 361 362 static inline sector_t bip_get_seed(struct bio_integrity_payload *bip) 363 { 364 return bip->bip_iter.bi_sector; 365 } 366 367 static inline void bip_set_seed(struct bio_integrity_payload *bip, 368 sector_t seed) 369 { 370 bip->bip_iter.bi_sector = seed; 371 } 372 373 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 374 375 extern void bio_trim(struct bio *bio, int offset, int size); 376 extern struct bio *bio_split(struct bio *bio, int sectors, 377 gfp_t gfp, struct bio_set *bs); 378 379 /** 380 * bio_next_split - get next @sectors from a bio, splitting if necessary 381 * @bio: bio to split 382 * @sectors: number of sectors to split from the front of @bio 383 * @gfp: gfp mask 384 * @bs: bio set to allocate from 385 * 386 * Returns a bio representing the next @sectors of @bio - if the bio is smaller 387 * than @sectors, returns the original bio unchanged. 388 */ 389 static inline struct bio *bio_next_split(struct bio *bio, int sectors, 390 gfp_t gfp, struct bio_set *bs) 391 { 392 if (sectors >= bio_sectors(bio)) 393 return bio; 394 395 return bio_split(bio, sectors, gfp, bs); 396 } 397 398 extern struct bio_set *bioset_create(unsigned int, unsigned int); 399 extern struct bio_set *bioset_create_nobvec(unsigned int, unsigned int); 400 extern void bioset_free(struct bio_set *); 401 extern mempool_t *biovec_create_pool(int pool_entries); 402 403 extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *); 404 extern void bio_put(struct bio *); 405 406 extern void __bio_clone_fast(struct bio *, struct bio *); 407 extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *); 408 extern struct bio *bio_clone_bioset(struct bio *, gfp_t, struct bio_set *bs); 409 410 extern struct bio_set *fs_bio_set; 411 412 static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs) 413 { 414 return bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set); 415 } 416 417 static inline struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask) 418 { 419 return bio_clone_bioset(bio, gfp_mask, fs_bio_set); 420 } 421 422 static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs) 423 { 424 return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL); 425 } 426 427 static inline struct bio *bio_clone_kmalloc(struct bio *bio, gfp_t gfp_mask) 428 { 429 return bio_clone_bioset(bio, gfp_mask, NULL); 430 431 } 432 433 extern void bio_endio(struct bio *); 434 435 static inline void bio_io_error(struct bio *bio) 436 { 437 bio->bi_error = -EIO; 438 bio_endio(bio); 439 } 440 441 struct request_queue; 442 extern int bio_phys_segments(struct request_queue *, struct bio *); 443 444 extern int submit_bio_wait(int rw, struct bio *bio); 445 extern void bio_advance(struct bio *, unsigned); 446 447 extern void bio_init(struct bio *); 448 extern void bio_reset(struct bio *); 449 void bio_chain(struct bio *, struct bio *); 450 451 extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int); 452 extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *, 453 unsigned int, unsigned int); 454 struct rq_map_data; 455 extern struct bio *bio_map_user_iov(struct request_queue *, 456 const struct iov_iter *, gfp_t); 457 extern void bio_unmap_user(struct bio *); 458 extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int, 459 gfp_t); 460 extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int, 461 gfp_t, int); 462 extern void bio_set_pages_dirty(struct bio *bio); 463 extern void bio_check_pages_dirty(struct bio *bio); 464 465 void generic_start_io_acct(int rw, unsigned long sectors, 466 struct hd_struct *part); 467 void generic_end_io_acct(int rw, struct hd_struct *part, 468 unsigned long start_time); 469 470 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 471 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform" 472 #endif 473 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 474 extern void bio_flush_dcache_pages(struct bio *bi); 475 #else 476 static inline void bio_flush_dcache_pages(struct bio *bi) 477 { 478 } 479 #endif 480 481 extern void bio_copy_data(struct bio *dst, struct bio *src); 482 extern int bio_alloc_pages(struct bio *bio, gfp_t gfp); 483 484 extern struct bio *bio_copy_user_iov(struct request_queue *, 485 struct rq_map_data *, 486 const struct iov_iter *, 487 gfp_t); 488 extern int bio_uncopy_user(struct bio *); 489 void zero_fill_bio(struct bio *bio); 490 extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *); 491 extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int); 492 extern unsigned int bvec_nr_vecs(unsigned short idx); 493 494 #ifdef CONFIG_BLK_CGROUP 495 int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css); 496 int bio_associate_current(struct bio *bio); 497 void bio_disassociate_task(struct bio *bio); 498 #else /* CONFIG_BLK_CGROUP */ 499 static inline int bio_associate_blkcg(struct bio *bio, 500 struct cgroup_subsys_state *blkcg_css) { return 0; } 501 static inline int bio_associate_current(struct bio *bio) { return -ENOENT; } 502 static inline void bio_disassociate_task(struct bio *bio) { } 503 #endif /* CONFIG_BLK_CGROUP */ 504 505 #ifdef CONFIG_HIGHMEM 506 /* 507 * remember never ever reenable interrupts between a bvec_kmap_irq and 508 * bvec_kunmap_irq! 509 */ 510 static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags) 511 { 512 unsigned long addr; 513 514 /* 515 * might not be a highmem page, but the preempt/irq count 516 * balancing is a lot nicer this way 517 */ 518 local_irq_save(*flags); 519 addr = (unsigned long) kmap_atomic(bvec->bv_page); 520 521 BUG_ON(addr & ~PAGE_MASK); 522 523 return (char *) addr + bvec->bv_offset; 524 } 525 526 static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags) 527 { 528 unsigned long ptr = (unsigned long) buffer & PAGE_MASK; 529 530 kunmap_atomic((void *) ptr); 531 local_irq_restore(*flags); 532 } 533 534 #else 535 static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags) 536 { 537 return page_address(bvec->bv_page) + bvec->bv_offset; 538 } 539 540 static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags) 541 { 542 *flags = 0; 543 } 544 #endif 545 546 static inline char *__bio_kmap_irq(struct bio *bio, struct bvec_iter iter, 547 unsigned long *flags) 548 { 549 return bvec_kmap_irq(&bio_iter_iovec(bio, iter), flags); 550 } 551 #define __bio_kunmap_irq(buf, flags) bvec_kunmap_irq(buf, flags) 552 553 #define bio_kmap_irq(bio, flags) \ 554 __bio_kmap_irq((bio), (bio)->bi_iter, (flags)) 555 #define bio_kunmap_irq(buf,flags) __bio_kunmap_irq(buf, flags) 556 557 /* 558 * BIO list management for use by remapping drivers (e.g. DM or MD) and loop. 559 * 560 * A bio_list anchors a singly-linked list of bios chained through the bi_next 561 * member of the bio. The bio_list also caches the last list member to allow 562 * fast access to the tail. 563 */ 564 struct bio_list { 565 struct bio *head; 566 struct bio *tail; 567 }; 568 569 static inline int bio_list_empty(const struct bio_list *bl) 570 { 571 return bl->head == NULL; 572 } 573 574 static inline void bio_list_init(struct bio_list *bl) 575 { 576 bl->head = bl->tail = NULL; 577 } 578 579 #define BIO_EMPTY_LIST { NULL, NULL } 580 581 #define bio_list_for_each(bio, bl) \ 582 for (bio = (bl)->head; bio; bio = bio->bi_next) 583 584 static inline unsigned bio_list_size(const struct bio_list *bl) 585 { 586 unsigned sz = 0; 587 struct bio *bio; 588 589 bio_list_for_each(bio, bl) 590 sz++; 591 592 return sz; 593 } 594 595 static inline void bio_list_add(struct bio_list *bl, struct bio *bio) 596 { 597 bio->bi_next = NULL; 598 599 if (bl->tail) 600 bl->tail->bi_next = bio; 601 else 602 bl->head = bio; 603 604 bl->tail = bio; 605 } 606 607 static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio) 608 { 609 bio->bi_next = bl->head; 610 611 bl->head = bio; 612 613 if (!bl->tail) 614 bl->tail = bio; 615 } 616 617 static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2) 618 { 619 if (!bl2->head) 620 return; 621 622 if (bl->tail) 623 bl->tail->bi_next = bl2->head; 624 else 625 bl->head = bl2->head; 626 627 bl->tail = bl2->tail; 628 } 629 630 static inline void bio_list_merge_head(struct bio_list *bl, 631 struct bio_list *bl2) 632 { 633 if (!bl2->head) 634 return; 635 636 if (bl->head) 637 bl2->tail->bi_next = bl->head; 638 else 639 bl->tail = bl2->tail; 640 641 bl->head = bl2->head; 642 } 643 644 static inline struct bio *bio_list_peek(struct bio_list *bl) 645 { 646 return bl->head; 647 } 648 649 static inline struct bio *bio_list_pop(struct bio_list *bl) 650 { 651 struct bio *bio = bl->head; 652 653 if (bio) { 654 bl->head = bl->head->bi_next; 655 if (!bl->head) 656 bl->tail = NULL; 657 658 bio->bi_next = NULL; 659 } 660 661 return bio; 662 } 663 664 static inline struct bio *bio_list_get(struct bio_list *bl) 665 { 666 struct bio *bio = bl->head; 667 668 bl->head = bl->tail = NULL; 669 670 return bio; 671 } 672 673 /* 674 * bio_set is used to allow other portions of the IO system to 675 * allocate their own private memory pools for bio and iovec structures. 676 * These memory pools in turn all allocate from the bio_slab 677 * and the bvec_slabs[]. 678 */ 679 #define BIO_POOL_SIZE 2 680 #define BIOVEC_NR_POOLS 6 681 #define BIOVEC_MAX_IDX (BIOVEC_NR_POOLS - 1) 682 683 struct bio_set { 684 struct kmem_cache *bio_slab; 685 unsigned int front_pad; 686 687 mempool_t *bio_pool; 688 mempool_t *bvec_pool; 689 #if defined(CONFIG_BLK_DEV_INTEGRITY) 690 mempool_t *bio_integrity_pool; 691 mempool_t *bvec_integrity_pool; 692 #endif 693 694 /* 695 * Deadlock avoidance for stacking block drivers: see comments in 696 * bio_alloc_bioset() for details 697 */ 698 spinlock_t rescue_lock; 699 struct bio_list rescue_list; 700 struct work_struct rescue_work; 701 struct workqueue_struct *rescue_workqueue; 702 }; 703 704 struct biovec_slab { 705 int nr_vecs; 706 char *name; 707 struct kmem_cache *slab; 708 }; 709 710 /* 711 * a small number of entries is fine, not going to be performance critical. 712 * basically we just need to survive 713 */ 714 #define BIO_SPLIT_ENTRIES 2 715 716 #if defined(CONFIG_BLK_DEV_INTEGRITY) 717 718 #define bip_for_each_vec(bvl, bip, iter) \ 719 for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter) 720 721 #define bio_for_each_integrity_vec(_bvl, _bio, _iter) \ 722 for_each_bio(_bio) \ 723 bip_for_each_vec(_bvl, _bio->bi_integrity, _iter) 724 725 extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int); 726 extern void bio_integrity_free(struct bio *); 727 extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int); 728 extern bool bio_integrity_enabled(struct bio *bio); 729 extern int bio_integrity_prep(struct bio *); 730 extern void bio_integrity_endio(struct bio *); 731 extern void bio_integrity_advance(struct bio *, unsigned int); 732 extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int); 733 extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t); 734 extern int bioset_integrity_create(struct bio_set *, int); 735 extern void bioset_integrity_free(struct bio_set *); 736 extern void bio_integrity_init(void); 737 738 #else /* CONFIG_BLK_DEV_INTEGRITY */ 739 740 static inline void *bio_integrity(struct bio *bio) 741 { 742 return NULL; 743 } 744 745 static inline bool bio_integrity_enabled(struct bio *bio) 746 { 747 return false; 748 } 749 750 static inline int bioset_integrity_create(struct bio_set *bs, int pool_size) 751 { 752 return 0; 753 } 754 755 static inline void bioset_integrity_free (struct bio_set *bs) 756 { 757 return; 758 } 759 760 static inline int bio_integrity_prep(struct bio *bio) 761 { 762 return 0; 763 } 764 765 static inline void bio_integrity_free(struct bio *bio) 766 { 767 return; 768 } 769 770 static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src, 771 gfp_t gfp_mask) 772 { 773 return 0; 774 } 775 776 static inline void bio_integrity_advance(struct bio *bio, 777 unsigned int bytes_done) 778 { 779 return; 780 } 781 782 static inline void bio_integrity_trim(struct bio *bio, unsigned int offset, 783 unsigned int sectors) 784 { 785 return; 786 } 787 788 static inline void bio_integrity_init(void) 789 { 790 return; 791 } 792 793 static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag) 794 { 795 return false; 796 } 797 798 static inline void *bio_integrity_alloc(struct bio * bio, gfp_t gfp, 799 unsigned int nr) 800 { 801 return ERR_PTR(-EINVAL); 802 } 803 804 static inline int bio_integrity_add_page(struct bio *bio, struct page *page, 805 unsigned int len, unsigned int offset) 806 { 807 return 0; 808 } 809 810 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 811 812 #endif /* CONFIG_BLOCK */ 813 #endif /* __LINUX_BIO_H */ 814