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 #include <linux/bug.h> 25 26 #ifdef CONFIG_BLOCK 27 28 #include <asm/io.h> 29 30 /* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */ 31 #include <linux/blk_types.h> 32 33 #define BIO_DEBUG 34 35 #ifdef BIO_DEBUG 36 #define BIO_BUG_ON BUG_ON 37 #else 38 #define BIO_BUG_ON 39 #endif 40 41 #ifdef CONFIG_THP_SWAP 42 #if HPAGE_PMD_NR > 256 43 #define BIO_MAX_PAGES HPAGE_PMD_NR 44 #else 45 #define BIO_MAX_PAGES 256 46 #endif 47 #else 48 #define BIO_MAX_PAGES 256 49 #endif 50 51 #define bio_prio(bio) (bio)->bi_ioprio 52 #define bio_set_prio(bio, prio) ((bio)->bi_ioprio = prio) 53 54 #define bio_iter_iovec(bio, iter) \ 55 bvec_iter_bvec((bio)->bi_io_vec, (iter)) 56 57 #define bio_iter_page(bio, iter) \ 58 bvec_iter_page((bio)->bi_io_vec, (iter)) 59 #define bio_iter_len(bio, iter) \ 60 bvec_iter_len((bio)->bi_io_vec, (iter)) 61 #define bio_iter_offset(bio, iter) \ 62 bvec_iter_offset((bio)->bi_io_vec, (iter)) 63 64 #define bio_page(bio) bio_iter_page((bio), (bio)->bi_iter) 65 #define bio_offset(bio) bio_iter_offset((bio), (bio)->bi_iter) 66 #define bio_iovec(bio) bio_iter_iovec((bio), (bio)->bi_iter) 67 68 #define bio_multiple_segments(bio) \ 69 ((bio)->bi_iter.bi_size != bio_iovec(bio).bv_len) 70 #define bio_sectors(bio) ((bio)->bi_iter.bi_size >> 9) 71 #define bio_end_sector(bio) ((bio)->bi_iter.bi_sector + bio_sectors((bio))) 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 /* 127 * will die 128 */ 129 #define bvec_to_phys(bv) (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset) 130 131 /* 132 * queues that have highmem support enabled may still need to revert to 133 * PIO transfers occasionally and thus map high pages temporarily. For 134 * permanent PIO fall back, user is probably better off disabling highmem 135 * I/O completely on that queue (see ide-dma for example) 136 */ 137 #define __bio_kmap_atomic(bio, iter) \ 138 (kmap_atomic(bio_iter_iovec((bio), (iter)).bv_page) + \ 139 bio_iter_iovec((bio), (iter)).bv_offset) 140 141 #define __bio_kunmap_atomic(addr) kunmap_atomic(addr) 142 143 /* 144 * merge helpers etc 145 */ 146 147 /* Default implementation of BIOVEC_PHYS_MERGEABLE */ 148 #define __BIOVEC_PHYS_MERGEABLE(vec1, vec2) \ 149 ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2))) 150 151 /* 152 * allow arch override, for eg virtualized architectures (put in asm/io.h) 153 */ 154 #ifndef BIOVEC_PHYS_MERGEABLE 155 #define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \ 156 __BIOVEC_PHYS_MERGEABLE(vec1, vec2) 157 #endif 158 159 #define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \ 160 (((addr1) | (mask)) == (((addr2) - 1) | (mask))) 161 #define BIOVEC_SEG_BOUNDARY(q, b1, b2) \ 162 __BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q))) 163 164 /* 165 * drivers should _never_ use the all version - the bio may have been split 166 * before it got to the driver and the driver won't own all of it 167 */ 168 #define bio_for_each_segment_all(bvl, bio, i) \ 169 for (i = 0, bvl = (bio)->bi_io_vec; i < (bio)->bi_vcnt; i++, bvl++) 170 171 static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter, 172 unsigned bytes) 173 { 174 iter->bi_sector += bytes >> 9; 175 176 if (bio_no_advance_iter(bio)) { 177 iter->bi_size -= bytes; 178 iter->bi_done += bytes; 179 } else { 180 bvec_iter_advance(bio->bi_io_vec, iter, bytes); 181 /* TODO: It is reasonable to complete bio with error here. */ 182 } 183 } 184 185 static inline bool bio_rewind_iter(struct bio *bio, struct bvec_iter *iter, 186 unsigned int bytes) 187 { 188 iter->bi_sector -= bytes >> 9; 189 190 if (bio_no_advance_iter(bio)) { 191 iter->bi_size += bytes; 192 iter->bi_done -= bytes; 193 return true; 194 } 195 196 return bvec_iter_rewind(bio->bi_io_vec, iter, bytes); 197 } 198 199 #define __bio_for_each_segment(bvl, bio, iter, start) \ 200 for (iter = (start); \ 201 (iter).bi_size && \ 202 ((bvl = bio_iter_iovec((bio), (iter))), 1); \ 203 bio_advance_iter((bio), &(iter), (bvl).bv_len)) 204 205 #define bio_for_each_segment(bvl, bio, iter) \ 206 __bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter) 207 208 #define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len) 209 210 static inline unsigned bio_segments(struct bio *bio) 211 { 212 unsigned segs = 0; 213 struct bio_vec bv; 214 struct bvec_iter iter; 215 216 /* 217 * We special case discard/write same/write zeroes, because they 218 * interpret bi_size differently: 219 */ 220 221 switch (bio_op(bio)) { 222 case REQ_OP_DISCARD: 223 case REQ_OP_SECURE_ERASE: 224 case REQ_OP_WRITE_ZEROES: 225 return 0; 226 case REQ_OP_WRITE_SAME: 227 return 1; 228 default: 229 break; 230 } 231 232 bio_for_each_segment(bv, bio, iter) 233 segs++; 234 235 return segs; 236 } 237 238 /* 239 * get a reference to a bio, so it won't disappear. the intended use is 240 * something like: 241 * 242 * bio_get(bio); 243 * submit_bio(rw, bio); 244 * if (bio->bi_flags ...) 245 * do_something 246 * bio_put(bio); 247 * 248 * without the bio_get(), it could potentially complete I/O before submit_bio 249 * returns. and then bio would be freed memory when if (bio->bi_flags ...) 250 * runs 251 */ 252 static inline void bio_get(struct bio *bio) 253 { 254 bio->bi_flags |= (1 << BIO_REFFED); 255 smp_mb__before_atomic(); 256 atomic_inc(&bio->__bi_cnt); 257 } 258 259 static inline void bio_cnt_set(struct bio *bio, unsigned int count) 260 { 261 if (count != 1) { 262 bio->bi_flags |= (1 << BIO_REFFED); 263 smp_mb__before_atomic(); 264 } 265 atomic_set(&bio->__bi_cnt, count); 266 } 267 268 static inline bool bio_flagged(struct bio *bio, unsigned int bit) 269 { 270 return (bio->bi_flags & (1U << bit)) != 0; 271 } 272 273 static inline void bio_set_flag(struct bio *bio, unsigned int bit) 274 { 275 bio->bi_flags |= (1U << bit); 276 } 277 278 static inline void bio_clear_flag(struct bio *bio, unsigned int bit) 279 { 280 bio->bi_flags &= ~(1U << bit); 281 } 282 283 static inline void bio_get_first_bvec(struct bio *bio, struct bio_vec *bv) 284 { 285 *bv = bio_iovec(bio); 286 } 287 288 static inline void bio_get_last_bvec(struct bio *bio, struct bio_vec *bv) 289 { 290 struct bvec_iter iter = bio->bi_iter; 291 int idx; 292 293 if (unlikely(!bio_multiple_segments(bio))) { 294 *bv = bio_iovec(bio); 295 return; 296 } 297 298 bio_advance_iter(bio, &iter, iter.bi_size); 299 300 if (!iter.bi_bvec_done) 301 idx = iter.bi_idx - 1; 302 else /* in the middle of bvec */ 303 idx = iter.bi_idx; 304 305 *bv = bio->bi_io_vec[idx]; 306 307 /* 308 * iter.bi_bvec_done records actual length of the last bvec 309 * if this bio ends in the middle of one io vector 310 */ 311 if (iter.bi_bvec_done) 312 bv->bv_len = iter.bi_bvec_done; 313 } 314 315 enum bip_flags { 316 BIP_BLOCK_INTEGRITY = 1 << 0, /* block layer owns integrity data */ 317 BIP_MAPPED_INTEGRITY = 1 << 1, /* ref tag has been remapped */ 318 BIP_CTRL_NOCHECK = 1 << 2, /* disable HBA integrity checking */ 319 BIP_DISK_NOCHECK = 1 << 3, /* disable disk integrity checking */ 320 BIP_IP_CHECKSUM = 1 << 4, /* IP checksum */ 321 }; 322 323 /* 324 * bio integrity payload 325 */ 326 struct bio_integrity_payload { 327 struct bio *bip_bio; /* parent bio */ 328 329 struct bvec_iter bip_iter; 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_opf & 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, int flags); 399 enum { 400 BIOSET_NEED_BVECS = BIT(0), 401 BIOSET_NEED_RESCUER = BIT(1), 402 }; 403 extern void bioset_free(struct bio_set *); 404 extern mempool_t *biovec_create_pool(int pool_entries); 405 406 extern struct bio *bio_alloc_bioset(gfp_t, unsigned int, struct bio_set *); 407 extern void bio_put(struct bio *); 408 409 extern void __bio_clone_fast(struct bio *, struct bio *); 410 extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *); 411 extern struct bio *bio_clone_bioset(struct bio *, gfp_t, struct bio_set *bs); 412 413 extern struct bio_set *fs_bio_set; 414 415 static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs) 416 { 417 return bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set); 418 } 419 420 static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs) 421 { 422 return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL); 423 } 424 425 static inline struct bio *bio_clone_kmalloc(struct bio *bio, gfp_t gfp_mask) 426 { 427 return bio_clone_bioset(bio, gfp_mask, NULL); 428 429 } 430 431 extern blk_qc_t submit_bio(struct bio *); 432 433 extern void bio_endio(struct bio *); 434 435 static inline void bio_io_error(struct bio *bio) 436 { 437 bio->bi_status = BLK_STS_IOERR; 438 bio_endio(bio); 439 } 440 441 static inline void bio_wouldblock_error(struct bio *bio) 442 { 443 bio->bi_status = BLK_STS_AGAIN; 444 bio_endio(bio); 445 } 446 447 struct request_queue; 448 extern int bio_phys_segments(struct request_queue *, struct bio *); 449 450 extern int submit_bio_wait(struct bio *bio); 451 extern void bio_advance(struct bio *, unsigned); 452 453 extern void bio_init(struct bio *bio, struct bio_vec *table, 454 unsigned short max_vecs); 455 extern void bio_uninit(struct bio *); 456 extern void bio_reset(struct bio *); 457 void bio_chain(struct bio *, struct bio *); 458 459 extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int); 460 extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *, 461 unsigned int, unsigned int); 462 int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter); 463 struct rq_map_data; 464 extern struct bio *bio_map_user_iov(struct request_queue *, 465 const struct iov_iter *, gfp_t); 466 extern void bio_unmap_user(struct bio *); 467 extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int, 468 gfp_t); 469 extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int, 470 gfp_t, int); 471 extern void bio_set_pages_dirty(struct bio *bio); 472 extern void bio_check_pages_dirty(struct bio *bio); 473 474 void generic_start_io_acct(struct request_queue *q, int rw, 475 unsigned long sectors, struct hd_struct *part); 476 void generic_end_io_acct(struct request_queue *q, int rw, 477 struct hd_struct *part, 478 unsigned long start_time); 479 480 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 481 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform" 482 #endif 483 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 484 extern void bio_flush_dcache_pages(struct bio *bi); 485 #else 486 static inline void bio_flush_dcache_pages(struct bio *bi) 487 { 488 } 489 #endif 490 491 extern void bio_copy_data(struct bio *dst, struct bio *src); 492 extern int bio_alloc_pages(struct bio *bio, gfp_t gfp); 493 extern void bio_free_pages(struct bio *bio); 494 495 extern struct bio *bio_copy_user_iov(struct request_queue *, 496 struct rq_map_data *, 497 const struct iov_iter *, 498 gfp_t); 499 extern int bio_uncopy_user(struct bio *); 500 void zero_fill_bio(struct bio *bio); 501 extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *); 502 extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int); 503 extern unsigned int bvec_nr_vecs(unsigned short idx); 504 505 #define bio_set_dev(bio, bdev) \ 506 do { \ 507 (bio)->bi_disk = (bdev)->bd_disk; \ 508 (bio)->bi_partno = (bdev)->bd_partno; \ 509 } while (0) 510 511 #define bio_copy_dev(dst, src) \ 512 do { \ 513 (dst)->bi_disk = (src)->bi_disk; \ 514 (dst)->bi_partno = (src)->bi_partno; \ 515 } while (0) 516 517 #define bio_dev(bio) \ 518 disk_devt((bio)->bi_disk) 519 520 #define bio_devname(bio, buf) \ 521 __bdevname(bio_dev(bio), (buf)) 522 523 #ifdef CONFIG_BLK_CGROUP 524 int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css); 525 int bio_associate_current(struct bio *bio); 526 void bio_disassociate_task(struct bio *bio); 527 void bio_clone_blkcg_association(struct bio *dst, struct bio *src); 528 #else /* CONFIG_BLK_CGROUP */ 529 static inline int bio_associate_blkcg(struct bio *bio, 530 struct cgroup_subsys_state *blkcg_css) { return 0; } 531 static inline int bio_associate_current(struct bio *bio) { return -ENOENT; } 532 static inline void bio_disassociate_task(struct bio *bio) { } 533 static inline void bio_clone_blkcg_association(struct bio *dst, 534 struct bio *src) { } 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 * Increment chain count for the bio. Make sure the CHAIN flag update 707 * is visible before the raised count. 708 */ 709 static inline void bio_inc_remaining(struct bio *bio) 710 { 711 bio_set_flag(bio, BIO_CHAIN); 712 smp_mb__before_atomic(); 713 atomic_inc(&bio->__bi_remaining); 714 } 715 716 /* 717 * bio_set is used to allow other portions of the IO system to 718 * allocate their own private memory pools for bio and iovec structures. 719 * These memory pools in turn all allocate from the bio_slab 720 * and the bvec_slabs[]. 721 */ 722 #define BIO_POOL_SIZE 2 723 724 struct bio_set { 725 struct kmem_cache *bio_slab; 726 unsigned int front_pad; 727 728 mempool_t *bio_pool; 729 mempool_t *bvec_pool; 730 #if defined(CONFIG_BLK_DEV_INTEGRITY) 731 mempool_t *bio_integrity_pool; 732 mempool_t *bvec_integrity_pool; 733 #endif 734 735 /* 736 * Deadlock avoidance for stacking block drivers: see comments in 737 * bio_alloc_bioset() for details 738 */ 739 spinlock_t rescue_lock; 740 struct bio_list rescue_list; 741 struct work_struct rescue_work; 742 struct workqueue_struct *rescue_workqueue; 743 }; 744 745 struct biovec_slab { 746 int nr_vecs; 747 char *name; 748 struct kmem_cache *slab; 749 }; 750 751 /* 752 * a small number of entries is fine, not going to be performance critical. 753 * basically we just need to survive 754 */ 755 #define BIO_SPLIT_ENTRIES 2 756 757 #if defined(CONFIG_BLK_DEV_INTEGRITY) 758 759 #define bip_for_each_vec(bvl, bip, iter) \ 760 for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter) 761 762 #define bio_for_each_integrity_vec(_bvl, _bio, _iter) \ 763 for_each_bio(_bio) \ 764 bip_for_each_vec(_bvl, _bio->bi_integrity, _iter) 765 766 extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int); 767 extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int); 768 extern bool bio_integrity_prep(struct bio *); 769 extern void bio_integrity_advance(struct bio *, unsigned int); 770 extern void bio_integrity_trim(struct bio *); 771 extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t); 772 extern int bioset_integrity_create(struct bio_set *, int); 773 extern void bioset_integrity_free(struct bio_set *); 774 extern void bio_integrity_init(void); 775 776 #else /* CONFIG_BLK_DEV_INTEGRITY */ 777 778 static inline void *bio_integrity(struct bio *bio) 779 { 780 return NULL; 781 } 782 783 static inline int bioset_integrity_create(struct bio_set *bs, int pool_size) 784 { 785 return 0; 786 } 787 788 static inline void bioset_integrity_free (struct bio_set *bs) 789 { 790 return; 791 } 792 793 static inline bool bio_integrity_prep(struct bio *bio) 794 { 795 return true; 796 } 797 798 static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src, 799 gfp_t gfp_mask) 800 { 801 return 0; 802 } 803 804 static inline void bio_integrity_advance(struct bio *bio, 805 unsigned int bytes_done) 806 { 807 return; 808 } 809 810 static inline void bio_integrity_trim(struct bio *bio) 811 { 812 return; 813 } 814 815 static inline void bio_integrity_init(void) 816 { 817 return; 818 } 819 820 static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag) 821 { 822 return false; 823 } 824 825 static inline void *bio_integrity_alloc(struct bio * bio, gfp_t gfp, 826 unsigned int nr) 827 { 828 return ERR_PTR(-EINVAL); 829 } 830 831 static inline int bio_integrity_add_page(struct bio *bio, struct page *page, 832 unsigned int len, unsigned int offset) 833 { 834 return 0; 835 } 836 837 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 838 839 #endif /* CONFIG_BLOCK */ 840 #endif /* __LINUX_BIO_H */ 841