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 static inline void bio_get_first_bvec(struct bio *bio, struct bio_vec *bv) 314 { 315 *bv = bio_iovec(bio); 316 } 317 318 static inline void bio_get_last_bvec(struct bio *bio, struct bio_vec *bv) 319 { 320 struct bvec_iter iter = bio->bi_iter; 321 int idx; 322 323 if (unlikely(!bio_multiple_segments(bio))) { 324 *bv = bio_iovec(bio); 325 return; 326 } 327 328 bio_advance_iter(bio, &iter, iter.bi_size); 329 330 if (!iter.bi_bvec_done) 331 idx = iter.bi_idx - 1; 332 else /* in the middle of bvec */ 333 idx = iter.bi_idx; 334 335 *bv = bio->bi_io_vec[idx]; 336 337 /* 338 * iter.bi_bvec_done records actual length of the last bvec 339 * if this bio ends in the middle of one io vector 340 */ 341 if (iter.bi_bvec_done) 342 bv->bv_len = iter.bi_bvec_done; 343 } 344 345 enum bip_flags { 346 BIP_BLOCK_INTEGRITY = 1 << 0, /* block layer owns integrity data */ 347 BIP_MAPPED_INTEGRITY = 1 << 1, /* ref tag has been remapped */ 348 BIP_CTRL_NOCHECK = 1 << 2, /* disable HBA integrity checking */ 349 BIP_DISK_NOCHECK = 1 << 3, /* disable disk integrity checking */ 350 BIP_IP_CHECKSUM = 1 << 4, /* IP checksum */ 351 }; 352 353 /* 354 * bio integrity payload 355 */ 356 struct bio_integrity_payload { 357 struct bio *bip_bio; /* parent bio */ 358 359 struct bvec_iter bip_iter; 360 361 bio_end_io_t *bip_end_io; /* saved I/O completion fn */ 362 363 unsigned short bip_slab; /* slab the bip came from */ 364 unsigned short bip_vcnt; /* # of integrity bio_vecs */ 365 unsigned short bip_max_vcnt; /* integrity bio_vec slots */ 366 unsigned short bip_flags; /* control flags */ 367 368 struct work_struct bip_work; /* I/O completion */ 369 370 struct bio_vec *bip_vec; 371 struct bio_vec bip_inline_vecs[0];/* embedded bvec array */ 372 }; 373 374 #if defined(CONFIG_BLK_DEV_INTEGRITY) 375 376 static inline struct bio_integrity_payload *bio_integrity(struct bio *bio) 377 { 378 if (bio->bi_rw & REQ_INTEGRITY) 379 return bio->bi_integrity; 380 381 return NULL; 382 } 383 384 static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag) 385 { 386 struct bio_integrity_payload *bip = bio_integrity(bio); 387 388 if (bip) 389 return bip->bip_flags & flag; 390 391 return false; 392 } 393 394 static inline sector_t bip_get_seed(struct bio_integrity_payload *bip) 395 { 396 return bip->bip_iter.bi_sector; 397 } 398 399 static inline void bip_set_seed(struct bio_integrity_payload *bip, 400 sector_t seed) 401 { 402 bip->bip_iter.bi_sector = seed; 403 } 404 405 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 406 407 extern void bio_trim(struct bio *bio, int offset, int size); 408 extern struct bio *bio_split(struct bio *bio, int sectors, 409 gfp_t gfp, struct bio_set *bs); 410 411 /** 412 * bio_next_split - get next @sectors from a bio, splitting if necessary 413 * @bio: bio to split 414 * @sectors: number of sectors to split from the front of @bio 415 * @gfp: gfp mask 416 * @bs: bio set to allocate from 417 * 418 * Returns a bio representing the next @sectors of @bio - if the bio is smaller 419 * than @sectors, returns the original bio unchanged. 420 */ 421 static inline struct bio *bio_next_split(struct bio *bio, int sectors, 422 gfp_t gfp, struct bio_set *bs) 423 { 424 if (sectors >= bio_sectors(bio)) 425 return bio; 426 427 return bio_split(bio, sectors, gfp, bs); 428 } 429 430 extern struct bio_set *bioset_create(unsigned int, unsigned int); 431 extern struct bio_set *bioset_create_nobvec(unsigned int, unsigned int); 432 extern void bioset_free(struct bio_set *); 433 extern mempool_t *biovec_create_pool(int pool_entries); 434 435 extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *); 436 extern void bio_put(struct bio *); 437 438 extern void __bio_clone_fast(struct bio *, struct bio *); 439 extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *); 440 extern struct bio *bio_clone_bioset(struct bio *, gfp_t, struct bio_set *bs); 441 442 extern struct bio_set *fs_bio_set; 443 444 static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs) 445 { 446 return bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set); 447 } 448 449 static inline struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask) 450 { 451 return bio_clone_bioset(bio, gfp_mask, fs_bio_set); 452 } 453 454 static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs) 455 { 456 return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL); 457 } 458 459 static inline struct bio *bio_clone_kmalloc(struct bio *bio, gfp_t gfp_mask) 460 { 461 return bio_clone_bioset(bio, gfp_mask, NULL); 462 463 } 464 465 extern void bio_endio(struct bio *); 466 467 static inline void bio_io_error(struct bio *bio) 468 { 469 bio->bi_error = -EIO; 470 bio_endio(bio); 471 } 472 473 struct request_queue; 474 extern int bio_phys_segments(struct request_queue *, struct bio *); 475 476 extern int submit_bio_wait(int rw, struct bio *bio); 477 extern void bio_advance(struct bio *, unsigned); 478 479 extern void bio_init(struct bio *); 480 extern void bio_reset(struct bio *); 481 void bio_chain(struct bio *, struct bio *); 482 483 extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int); 484 extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *, 485 unsigned int, unsigned int); 486 struct rq_map_data; 487 extern struct bio *bio_map_user_iov(struct request_queue *, 488 const struct iov_iter *, gfp_t); 489 extern void bio_unmap_user(struct bio *); 490 extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int, 491 gfp_t); 492 extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int, 493 gfp_t, int); 494 extern void bio_set_pages_dirty(struct bio *bio); 495 extern void bio_check_pages_dirty(struct bio *bio); 496 497 void generic_start_io_acct(int rw, unsigned long sectors, 498 struct hd_struct *part); 499 void generic_end_io_acct(int rw, struct hd_struct *part, 500 unsigned long start_time); 501 502 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 503 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform" 504 #endif 505 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 506 extern void bio_flush_dcache_pages(struct bio *bi); 507 #else 508 static inline void bio_flush_dcache_pages(struct bio *bi) 509 { 510 } 511 #endif 512 513 extern void bio_copy_data(struct bio *dst, struct bio *src); 514 extern int bio_alloc_pages(struct bio *bio, gfp_t gfp); 515 516 extern struct bio *bio_copy_user_iov(struct request_queue *, 517 struct rq_map_data *, 518 const struct iov_iter *, 519 gfp_t); 520 extern int bio_uncopy_user(struct bio *); 521 void zero_fill_bio(struct bio *bio); 522 extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *); 523 extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int); 524 extern unsigned int bvec_nr_vecs(unsigned short idx); 525 526 #ifdef CONFIG_BLK_CGROUP 527 int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css); 528 int bio_associate_current(struct bio *bio); 529 void bio_disassociate_task(struct bio *bio); 530 #else /* CONFIG_BLK_CGROUP */ 531 static inline int bio_associate_blkcg(struct bio *bio, 532 struct cgroup_subsys_state *blkcg_css) { return 0; } 533 static inline int bio_associate_current(struct bio *bio) { return -ENOENT; } 534 static inline void bio_disassociate_task(struct bio *bio) { } 535 #endif /* CONFIG_BLK_CGROUP */ 536 537 #ifdef CONFIG_HIGHMEM 538 /* 539 * remember never ever reenable interrupts between a bvec_kmap_irq and 540 * bvec_kunmap_irq! 541 */ 542 static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags) 543 { 544 unsigned long addr; 545 546 /* 547 * might not be a highmem page, but the preempt/irq count 548 * balancing is a lot nicer this way 549 */ 550 local_irq_save(*flags); 551 addr = (unsigned long) kmap_atomic(bvec->bv_page); 552 553 BUG_ON(addr & ~PAGE_MASK); 554 555 return (char *) addr + bvec->bv_offset; 556 } 557 558 static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags) 559 { 560 unsigned long ptr = (unsigned long) buffer & PAGE_MASK; 561 562 kunmap_atomic((void *) ptr); 563 local_irq_restore(*flags); 564 } 565 566 #else 567 static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags) 568 { 569 return page_address(bvec->bv_page) + bvec->bv_offset; 570 } 571 572 static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags) 573 { 574 *flags = 0; 575 } 576 #endif 577 578 static inline char *__bio_kmap_irq(struct bio *bio, struct bvec_iter iter, 579 unsigned long *flags) 580 { 581 return bvec_kmap_irq(&bio_iter_iovec(bio, iter), flags); 582 } 583 #define __bio_kunmap_irq(buf, flags) bvec_kunmap_irq(buf, flags) 584 585 #define bio_kmap_irq(bio, flags) \ 586 __bio_kmap_irq((bio), (bio)->bi_iter, (flags)) 587 #define bio_kunmap_irq(buf,flags) __bio_kunmap_irq(buf, flags) 588 589 /* 590 * BIO list management for use by remapping drivers (e.g. DM or MD) and loop. 591 * 592 * A bio_list anchors a singly-linked list of bios chained through the bi_next 593 * member of the bio. The bio_list also caches the last list member to allow 594 * fast access to the tail. 595 */ 596 struct bio_list { 597 struct bio *head; 598 struct bio *tail; 599 }; 600 601 static inline int bio_list_empty(const struct bio_list *bl) 602 { 603 return bl->head == NULL; 604 } 605 606 static inline void bio_list_init(struct bio_list *bl) 607 { 608 bl->head = bl->tail = NULL; 609 } 610 611 #define BIO_EMPTY_LIST { NULL, NULL } 612 613 #define bio_list_for_each(bio, bl) \ 614 for (bio = (bl)->head; bio; bio = bio->bi_next) 615 616 static inline unsigned bio_list_size(const struct bio_list *bl) 617 { 618 unsigned sz = 0; 619 struct bio *bio; 620 621 bio_list_for_each(bio, bl) 622 sz++; 623 624 return sz; 625 } 626 627 static inline void bio_list_add(struct bio_list *bl, struct bio *bio) 628 { 629 bio->bi_next = NULL; 630 631 if (bl->tail) 632 bl->tail->bi_next = bio; 633 else 634 bl->head = bio; 635 636 bl->tail = bio; 637 } 638 639 static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio) 640 { 641 bio->bi_next = bl->head; 642 643 bl->head = bio; 644 645 if (!bl->tail) 646 bl->tail = bio; 647 } 648 649 static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2) 650 { 651 if (!bl2->head) 652 return; 653 654 if (bl->tail) 655 bl->tail->bi_next = bl2->head; 656 else 657 bl->head = bl2->head; 658 659 bl->tail = bl2->tail; 660 } 661 662 static inline void bio_list_merge_head(struct bio_list *bl, 663 struct bio_list *bl2) 664 { 665 if (!bl2->head) 666 return; 667 668 if (bl->head) 669 bl2->tail->bi_next = bl->head; 670 else 671 bl->tail = bl2->tail; 672 673 bl->head = bl2->head; 674 } 675 676 static inline struct bio *bio_list_peek(struct bio_list *bl) 677 { 678 return bl->head; 679 } 680 681 static inline struct bio *bio_list_pop(struct bio_list *bl) 682 { 683 struct bio *bio = bl->head; 684 685 if (bio) { 686 bl->head = bl->head->bi_next; 687 if (!bl->head) 688 bl->tail = NULL; 689 690 bio->bi_next = NULL; 691 } 692 693 return bio; 694 } 695 696 static inline struct bio *bio_list_get(struct bio_list *bl) 697 { 698 struct bio *bio = bl->head; 699 700 bl->head = bl->tail = NULL; 701 702 return bio; 703 } 704 705 /* 706 * bio_set is used to allow other portions of the IO system to 707 * allocate their own private memory pools for bio and iovec structures. 708 * These memory pools in turn all allocate from the bio_slab 709 * and the bvec_slabs[]. 710 */ 711 #define BIO_POOL_SIZE 2 712 #define BIOVEC_NR_POOLS 6 713 #define BIOVEC_MAX_IDX (BIOVEC_NR_POOLS - 1) 714 715 struct bio_set { 716 struct kmem_cache *bio_slab; 717 unsigned int front_pad; 718 719 mempool_t *bio_pool; 720 mempool_t *bvec_pool; 721 #if defined(CONFIG_BLK_DEV_INTEGRITY) 722 mempool_t *bio_integrity_pool; 723 mempool_t *bvec_integrity_pool; 724 #endif 725 726 /* 727 * Deadlock avoidance for stacking block drivers: see comments in 728 * bio_alloc_bioset() for details 729 */ 730 spinlock_t rescue_lock; 731 struct bio_list rescue_list; 732 struct work_struct rescue_work; 733 struct workqueue_struct *rescue_workqueue; 734 }; 735 736 struct biovec_slab { 737 int nr_vecs; 738 char *name; 739 struct kmem_cache *slab; 740 }; 741 742 /* 743 * a small number of entries is fine, not going to be performance critical. 744 * basically we just need to survive 745 */ 746 #define BIO_SPLIT_ENTRIES 2 747 748 #if defined(CONFIG_BLK_DEV_INTEGRITY) 749 750 #define bip_for_each_vec(bvl, bip, iter) \ 751 for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter) 752 753 #define bio_for_each_integrity_vec(_bvl, _bio, _iter) \ 754 for_each_bio(_bio) \ 755 bip_for_each_vec(_bvl, _bio->bi_integrity, _iter) 756 757 extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int); 758 extern void bio_integrity_free(struct bio *); 759 extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int); 760 extern bool bio_integrity_enabled(struct bio *bio); 761 extern int bio_integrity_prep(struct bio *); 762 extern void bio_integrity_endio(struct bio *); 763 extern void bio_integrity_advance(struct bio *, unsigned int); 764 extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int); 765 extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t); 766 extern int bioset_integrity_create(struct bio_set *, int); 767 extern void bioset_integrity_free(struct bio_set *); 768 extern void bio_integrity_init(void); 769 770 #else /* CONFIG_BLK_DEV_INTEGRITY */ 771 772 static inline void *bio_integrity(struct bio *bio) 773 { 774 return NULL; 775 } 776 777 static inline bool bio_integrity_enabled(struct bio *bio) 778 { 779 return false; 780 } 781 782 static inline int bioset_integrity_create(struct bio_set *bs, int pool_size) 783 { 784 return 0; 785 } 786 787 static inline void bioset_integrity_free (struct bio_set *bs) 788 { 789 return; 790 } 791 792 static inline int bio_integrity_prep(struct bio *bio) 793 { 794 return 0; 795 } 796 797 static inline void bio_integrity_free(struct bio *bio) 798 { 799 return; 800 } 801 802 static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src, 803 gfp_t gfp_mask) 804 { 805 return 0; 806 } 807 808 static inline void bio_integrity_advance(struct bio *bio, 809 unsigned int bytes_done) 810 { 811 return; 812 } 813 814 static inline void bio_integrity_trim(struct bio *bio, unsigned int offset, 815 unsigned int sectors) 816 { 817 return; 818 } 819 820 static inline void bio_integrity_init(void) 821 { 822 return; 823 } 824 825 static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag) 826 { 827 return false; 828 } 829 830 static inline void *bio_integrity_alloc(struct bio * bio, gfp_t gfp, 831 unsigned int nr) 832 { 833 return ERR_PTR(-EINVAL); 834 } 835 836 static inline int bio_integrity_add_page(struct bio *bio, struct page *page, 837 unsigned int len, unsigned int offset) 838 { 839 return 0; 840 } 841 842 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 843 844 #endif /* CONFIG_BLOCK */ 845 #endif /* __LINUX_BIO_H */ 846