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 * Check if adding a bio_vec after bprv with offset would create a gap in 191 * the SG list. Most drivers don't care about this, but some do. 192 */ 193 static inline bool bvec_gap_to_prev(struct bio_vec *bprv, unsigned int offset) 194 { 195 return offset || ((bprv->bv_offset + bprv->bv_len) & (PAGE_SIZE - 1)); 196 } 197 198 #define bio_io_error(bio) bio_endio((bio), -EIO) 199 200 /* 201 * drivers should _never_ use the all version - the bio may have been split 202 * before it got to the driver and the driver won't own all of it 203 */ 204 #define bio_for_each_segment_all(bvl, bio, i) \ 205 for (i = 0, bvl = (bio)->bi_io_vec; i < (bio)->bi_vcnt; i++, bvl++) 206 207 static inline void bvec_iter_advance(struct bio_vec *bv, struct bvec_iter *iter, 208 unsigned bytes) 209 { 210 WARN_ONCE(bytes > iter->bi_size, 211 "Attempted to advance past end of bvec iter\n"); 212 213 while (bytes) { 214 unsigned len = min(bytes, bvec_iter_len(bv, *iter)); 215 216 bytes -= len; 217 iter->bi_size -= len; 218 iter->bi_bvec_done += len; 219 220 if (iter->bi_bvec_done == __bvec_iter_bvec(bv, *iter)->bv_len) { 221 iter->bi_bvec_done = 0; 222 iter->bi_idx++; 223 } 224 } 225 } 226 227 #define for_each_bvec(bvl, bio_vec, iter, start) \ 228 for (iter = (start); \ 229 (iter).bi_size && \ 230 ((bvl = bvec_iter_bvec((bio_vec), (iter))), 1); \ 231 bvec_iter_advance((bio_vec), &(iter), (bvl).bv_len)) 232 233 234 static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter, 235 unsigned bytes) 236 { 237 iter->bi_sector += bytes >> 9; 238 239 if (bio->bi_rw & BIO_NO_ADVANCE_ITER_MASK) 240 iter->bi_size -= bytes; 241 else 242 bvec_iter_advance(bio->bi_io_vec, iter, bytes); 243 } 244 245 #define __bio_for_each_segment(bvl, bio, iter, start) \ 246 for (iter = (start); \ 247 (iter).bi_size && \ 248 ((bvl = bio_iter_iovec((bio), (iter))), 1); \ 249 bio_advance_iter((bio), &(iter), (bvl).bv_len)) 250 251 #define bio_for_each_segment(bvl, bio, iter) \ 252 __bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter) 253 254 #define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len) 255 256 static inline unsigned bio_segments(struct bio *bio) 257 { 258 unsigned segs = 0; 259 struct bio_vec bv; 260 struct bvec_iter iter; 261 262 /* 263 * We special case discard/write same, because they interpret bi_size 264 * differently: 265 */ 266 267 if (bio->bi_rw & REQ_DISCARD) 268 return 1; 269 270 if (bio->bi_rw & REQ_WRITE_SAME) 271 return 1; 272 273 bio_for_each_segment(bv, bio, iter) 274 segs++; 275 276 return segs; 277 } 278 279 /* 280 * get a reference to a bio, so it won't disappear. the intended use is 281 * something like: 282 * 283 * bio_get(bio); 284 * submit_bio(rw, bio); 285 * if (bio->bi_flags ...) 286 * do_something 287 * bio_put(bio); 288 * 289 * without the bio_get(), it could potentially complete I/O before submit_bio 290 * returns. and then bio would be freed memory when if (bio->bi_flags ...) 291 * runs 292 */ 293 static inline void bio_get(struct bio *bio) 294 { 295 bio->bi_flags |= (1 << BIO_REFFED); 296 smp_mb__before_atomic(); 297 atomic_inc(&bio->__bi_cnt); 298 } 299 300 static inline void bio_cnt_set(struct bio *bio, unsigned int count) 301 { 302 if (count != 1) { 303 bio->bi_flags |= (1 << BIO_REFFED); 304 smp_mb__before_atomic(); 305 } 306 atomic_set(&bio->__bi_cnt, count); 307 } 308 309 enum bip_flags { 310 BIP_BLOCK_INTEGRITY = 1 << 0, /* block layer owns integrity data */ 311 BIP_MAPPED_INTEGRITY = 1 << 1, /* ref tag has been remapped */ 312 BIP_CTRL_NOCHECK = 1 << 2, /* disable HBA integrity checking */ 313 BIP_DISK_NOCHECK = 1 << 3, /* disable disk integrity checking */ 314 BIP_IP_CHECKSUM = 1 << 4, /* IP checksum */ 315 }; 316 317 #if defined(CONFIG_BLK_DEV_INTEGRITY) 318 319 static inline struct bio_integrity_payload *bio_integrity(struct bio *bio) 320 { 321 if (bio->bi_rw & REQ_INTEGRITY) 322 return bio->bi_integrity; 323 324 return NULL; 325 } 326 327 /* 328 * bio integrity payload 329 */ 330 struct bio_integrity_payload { 331 struct bio *bip_bio; /* parent bio */ 332 333 struct bvec_iter bip_iter; 334 335 bio_end_io_t *bip_end_io; /* saved I/O completion fn */ 336 337 unsigned short bip_slab; /* slab the bip came from */ 338 unsigned short bip_vcnt; /* # of integrity bio_vecs */ 339 unsigned short bip_max_vcnt; /* integrity bio_vec slots */ 340 unsigned short bip_flags; /* control flags */ 341 342 struct work_struct bip_work; /* I/O completion */ 343 344 struct bio_vec *bip_vec; 345 struct bio_vec bip_inline_vecs[0];/* embedded bvec array */ 346 }; 347 348 static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag) 349 { 350 struct bio_integrity_payload *bip = bio_integrity(bio); 351 352 if (bip) 353 return bip->bip_flags & flag; 354 355 return false; 356 } 357 358 static inline sector_t bip_get_seed(struct bio_integrity_payload *bip) 359 { 360 return bip->bip_iter.bi_sector; 361 } 362 363 static inline void bip_set_seed(struct bio_integrity_payload *bip, 364 sector_t seed) 365 { 366 bip->bip_iter.bi_sector = seed; 367 } 368 369 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 370 371 extern void bio_trim(struct bio *bio, int offset, int size); 372 extern struct bio *bio_split(struct bio *bio, int sectors, 373 gfp_t gfp, struct bio_set *bs); 374 375 /** 376 * bio_next_split - get next @sectors from a bio, splitting if necessary 377 * @bio: bio to split 378 * @sectors: number of sectors to split from the front of @bio 379 * @gfp: gfp mask 380 * @bs: bio set to allocate from 381 * 382 * Returns a bio representing the next @sectors of @bio - if the bio is smaller 383 * than @sectors, returns the original bio unchanged. 384 */ 385 static inline struct bio *bio_next_split(struct bio *bio, int sectors, 386 gfp_t gfp, struct bio_set *bs) 387 { 388 if (sectors >= bio_sectors(bio)) 389 return bio; 390 391 return bio_split(bio, sectors, gfp, bs); 392 } 393 394 extern struct bio_set *bioset_create(unsigned int, unsigned int); 395 extern struct bio_set *bioset_create_nobvec(unsigned int, unsigned int); 396 extern void bioset_free(struct bio_set *); 397 extern mempool_t *biovec_create_pool(int pool_entries); 398 399 extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *); 400 extern void bio_put(struct bio *); 401 402 extern void __bio_clone_fast(struct bio *, struct bio *); 403 extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *); 404 extern struct bio *bio_clone_bioset(struct bio *, gfp_t, struct bio_set *bs); 405 406 extern struct bio_set *fs_bio_set; 407 408 static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs) 409 { 410 return bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set); 411 } 412 413 static inline struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask) 414 { 415 return bio_clone_bioset(bio, gfp_mask, fs_bio_set); 416 } 417 418 static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs) 419 { 420 return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL); 421 } 422 423 static inline struct bio *bio_clone_kmalloc(struct bio *bio, gfp_t gfp_mask) 424 { 425 return bio_clone_bioset(bio, gfp_mask, NULL); 426 427 } 428 429 extern void bio_endio(struct bio *, int); 430 struct request_queue; 431 extern int bio_phys_segments(struct request_queue *, struct bio *); 432 433 extern int submit_bio_wait(int rw, struct bio *bio); 434 extern void bio_advance(struct bio *, unsigned); 435 436 extern void bio_init(struct bio *); 437 extern void bio_reset(struct bio *); 438 void bio_chain(struct bio *, struct bio *); 439 440 extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int); 441 extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *, 442 unsigned int, unsigned int); 443 extern int bio_get_nr_vecs(struct block_device *); 444 struct rq_map_data; 445 extern struct bio *bio_map_user_iov(struct request_queue *, 446 const struct iov_iter *, gfp_t); 447 extern void bio_unmap_user(struct bio *); 448 extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int, 449 gfp_t); 450 extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int, 451 gfp_t, int); 452 extern void bio_set_pages_dirty(struct bio *bio); 453 extern void bio_check_pages_dirty(struct bio *bio); 454 455 void generic_start_io_acct(int rw, unsigned long sectors, 456 struct hd_struct *part); 457 void generic_end_io_acct(int rw, struct hd_struct *part, 458 unsigned long start_time); 459 460 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 461 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform" 462 #endif 463 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 464 extern void bio_flush_dcache_pages(struct bio *bi); 465 #else 466 static inline void bio_flush_dcache_pages(struct bio *bi) 467 { 468 } 469 #endif 470 471 extern void bio_copy_data(struct bio *dst, struct bio *src); 472 extern int bio_alloc_pages(struct bio *bio, gfp_t gfp); 473 474 extern struct bio *bio_copy_user_iov(struct request_queue *, 475 struct rq_map_data *, 476 const struct iov_iter *, 477 gfp_t); 478 extern int bio_uncopy_user(struct bio *); 479 void zero_fill_bio(struct bio *bio); 480 extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *); 481 extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int); 482 extern unsigned int bvec_nr_vecs(unsigned short idx); 483 484 #ifdef CONFIG_BLK_CGROUP 485 int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css); 486 int bio_associate_current(struct bio *bio); 487 void bio_disassociate_task(struct bio *bio); 488 #else /* CONFIG_BLK_CGROUP */ 489 static inline int bio_associate_blkcg(struct bio *bio, 490 struct cgroup_subsys_state *blkcg_css) { return 0; } 491 static inline int bio_associate_current(struct bio *bio) { return -ENOENT; } 492 static inline void bio_disassociate_task(struct bio *bio) { } 493 #endif /* CONFIG_BLK_CGROUP */ 494 495 #ifdef CONFIG_HIGHMEM 496 /* 497 * remember never ever reenable interrupts between a bvec_kmap_irq and 498 * bvec_kunmap_irq! 499 */ 500 static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags) 501 { 502 unsigned long addr; 503 504 /* 505 * might not be a highmem page, but the preempt/irq count 506 * balancing is a lot nicer this way 507 */ 508 local_irq_save(*flags); 509 addr = (unsigned long) kmap_atomic(bvec->bv_page); 510 511 BUG_ON(addr & ~PAGE_MASK); 512 513 return (char *) addr + bvec->bv_offset; 514 } 515 516 static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags) 517 { 518 unsigned long ptr = (unsigned long) buffer & PAGE_MASK; 519 520 kunmap_atomic((void *) ptr); 521 local_irq_restore(*flags); 522 } 523 524 #else 525 static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags) 526 { 527 return page_address(bvec->bv_page) + bvec->bv_offset; 528 } 529 530 static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags) 531 { 532 *flags = 0; 533 } 534 #endif 535 536 static inline char *__bio_kmap_irq(struct bio *bio, struct bvec_iter iter, 537 unsigned long *flags) 538 { 539 return bvec_kmap_irq(&bio_iter_iovec(bio, iter), flags); 540 } 541 #define __bio_kunmap_irq(buf, flags) bvec_kunmap_irq(buf, flags) 542 543 #define bio_kmap_irq(bio, flags) \ 544 __bio_kmap_irq((bio), (bio)->bi_iter, (flags)) 545 #define bio_kunmap_irq(buf,flags) __bio_kunmap_irq(buf, flags) 546 547 /* 548 * BIO list management for use by remapping drivers (e.g. DM or MD) and loop. 549 * 550 * A bio_list anchors a singly-linked list of bios chained through the bi_next 551 * member of the bio. The bio_list also caches the last list member to allow 552 * fast access to the tail. 553 */ 554 struct bio_list { 555 struct bio *head; 556 struct bio *tail; 557 }; 558 559 static inline int bio_list_empty(const struct bio_list *bl) 560 { 561 return bl->head == NULL; 562 } 563 564 static inline void bio_list_init(struct bio_list *bl) 565 { 566 bl->head = bl->tail = NULL; 567 } 568 569 #define BIO_EMPTY_LIST { NULL, NULL } 570 571 #define bio_list_for_each(bio, bl) \ 572 for (bio = (bl)->head; bio; bio = bio->bi_next) 573 574 static inline unsigned bio_list_size(const struct bio_list *bl) 575 { 576 unsigned sz = 0; 577 struct bio *bio; 578 579 bio_list_for_each(bio, bl) 580 sz++; 581 582 return sz; 583 } 584 585 static inline void bio_list_add(struct bio_list *bl, struct bio *bio) 586 { 587 bio->bi_next = NULL; 588 589 if (bl->tail) 590 bl->tail->bi_next = bio; 591 else 592 bl->head = bio; 593 594 bl->tail = bio; 595 } 596 597 static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio) 598 { 599 bio->bi_next = bl->head; 600 601 bl->head = bio; 602 603 if (!bl->tail) 604 bl->tail = bio; 605 } 606 607 static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2) 608 { 609 if (!bl2->head) 610 return; 611 612 if (bl->tail) 613 bl->tail->bi_next = bl2->head; 614 else 615 bl->head = bl2->head; 616 617 bl->tail = bl2->tail; 618 } 619 620 static inline void bio_list_merge_head(struct bio_list *bl, 621 struct bio_list *bl2) 622 { 623 if (!bl2->head) 624 return; 625 626 if (bl->head) 627 bl2->tail->bi_next = bl->head; 628 else 629 bl->tail = bl2->tail; 630 631 bl->head = bl2->head; 632 } 633 634 static inline struct bio *bio_list_peek(struct bio_list *bl) 635 { 636 return bl->head; 637 } 638 639 static inline struct bio *bio_list_pop(struct bio_list *bl) 640 { 641 struct bio *bio = bl->head; 642 643 if (bio) { 644 bl->head = bl->head->bi_next; 645 if (!bl->head) 646 bl->tail = NULL; 647 648 bio->bi_next = NULL; 649 } 650 651 return bio; 652 } 653 654 static inline struct bio *bio_list_get(struct bio_list *bl) 655 { 656 struct bio *bio = bl->head; 657 658 bl->head = bl->tail = NULL; 659 660 return bio; 661 } 662 663 /* 664 * bio_set is used to allow other portions of the IO system to 665 * allocate their own private memory pools for bio and iovec structures. 666 * These memory pools in turn all allocate from the bio_slab 667 * and the bvec_slabs[]. 668 */ 669 #define BIO_POOL_SIZE 2 670 #define BIOVEC_NR_POOLS 6 671 #define BIOVEC_MAX_IDX (BIOVEC_NR_POOLS - 1) 672 673 struct bio_set { 674 struct kmem_cache *bio_slab; 675 unsigned int front_pad; 676 677 mempool_t *bio_pool; 678 mempool_t *bvec_pool; 679 #if defined(CONFIG_BLK_DEV_INTEGRITY) 680 mempool_t *bio_integrity_pool; 681 mempool_t *bvec_integrity_pool; 682 #endif 683 684 /* 685 * Deadlock avoidance for stacking block drivers: see comments in 686 * bio_alloc_bioset() for details 687 */ 688 spinlock_t rescue_lock; 689 struct bio_list rescue_list; 690 struct work_struct rescue_work; 691 struct workqueue_struct *rescue_workqueue; 692 }; 693 694 struct biovec_slab { 695 int nr_vecs; 696 char *name; 697 struct kmem_cache *slab; 698 }; 699 700 /* 701 * a small number of entries is fine, not going to be performance critical. 702 * basically we just need to survive 703 */ 704 #define BIO_SPLIT_ENTRIES 2 705 706 #if defined(CONFIG_BLK_DEV_INTEGRITY) 707 708 #define bip_for_each_vec(bvl, bip, iter) \ 709 for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter) 710 711 #define bio_for_each_integrity_vec(_bvl, _bio, _iter) \ 712 for_each_bio(_bio) \ 713 bip_for_each_vec(_bvl, _bio->bi_integrity, _iter) 714 715 extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int); 716 extern void bio_integrity_free(struct bio *); 717 extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int); 718 extern bool bio_integrity_enabled(struct bio *bio); 719 extern int bio_integrity_prep(struct bio *); 720 extern void bio_integrity_endio(struct bio *, int); 721 extern void bio_integrity_advance(struct bio *, unsigned int); 722 extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int); 723 extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t); 724 extern int bioset_integrity_create(struct bio_set *, int); 725 extern void bioset_integrity_free(struct bio_set *); 726 extern void bio_integrity_init(void); 727 728 #else /* CONFIG_BLK_DEV_INTEGRITY */ 729 730 static inline void *bio_integrity(struct bio *bio) 731 { 732 return NULL; 733 } 734 735 static inline bool bio_integrity_enabled(struct bio *bio) 736 { 737 return false; 738 } 739 740 static inline int bioset_integrity_create(struct bio_set *bs, int pool_size) 741 { 742 return 0; 743 } 744 745 static inline void bioset_integrity_free (struct bio_set *bs) 746 { 747 return; 748 } 749 750 static inline int bio_integrity_prep(struct bio *bio) 751 { 752 return 0; 753 } 754 755 static inline void bio_integrity_free(struct bio *bio) 756 { 757 return; 758 } 759 760 static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src, 761 gfp_t gfp_mask) 762 { 763 return 0; 764 } 765 766 static inline void bio_integrity_advance(struct bio *bio, 767 unsigned int bytes_done) 768 { 769 return; 770 } 771 772 static inline void bio_integrity_trim(struct bio *bio, unsigned int offset, 773 unsigned int sectors) 774 { 775 return; 776 } 777 778 static inline void bio_integrity_init(void) 779 { 780 return; 781 } 782 783 static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag) 784 { 785 return false; 786 } 787 788 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 789 790 #endif /* CONFIG_BLOCK */ 791 #endif /* __LINUX_BIO_H */ 792