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1/* SPDX-License-Identifier: GPL-2.0 */2/*3 * Copyright (C) 2001 Jens Axboe <axboe@suse.de>4 */5#ifndef __LINUX_BIO_H6#define __LINUX_BIO_H7 8#include <linux/mempool.h>9/* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */10#include <linux/blk_types.h>11#include <linux/uio.h>12 13#define BIO_MAX_VECS 256U14 15struct queue_limits;16 17static inline unsigned int bio_max_segs(unsigned int nr_segs)18{19 return min(nr_segs, BIO_MAX_VECS);20}21 22#define bio_prio(bio) (bio)->bi_ioprio23#define bio_set_prio(bio, prio) ((bio)->bi_ioprio = prio)24 25#define bio_iter_iovec(bio, iter) \26 bvec_iter_bvec((bio)->bi_io_vec, (iter))27 28#define bio_iter_page(bio, iter) \29 bvec_iter_page((bio)->bi_io_vec, (iter))30#define bio_iter_len(bio, iter) \31 bvec_iter_len((bio)->bi_io_vec, (iter))32#define bio_iter_offset(bio, iter) \33 bvec_iter_offset((bio)->bi_io_vec, (iter))34 35#define bio_page(bio) bio_iter_page((bio), (bio)->bi_iter)36#define bio_offset(bio) bio_iter_offset((bio), (bio)->bi_iter)37#define bio_iovec(bio) bio_iter_iovec((bio), (bio)->bi_iter)38 39#define bvec_iter_sectors(iter) ((iter).bi_size >> 9)40#define bvec_iter_end_sector(iter) ((iter).bi_sector + bvec_iter_sectors((iter)))41 42#define bio_sectors(bio) bvec_iter_sectors((bio)->bi_iter)43#define bio_end_sector(bio) bvec_iter_end_sector((bio)->bi_iter)44 45/*46 * Return the data direction, READ or WRITE.47 */48#define bio_data_dir(bio) \49 (op_is_write(bio_op(bio)) ? WRITE : READ)50 51/*52 * Check whether this bio carries any data or not. A NULL bio is allowed.53 */54static inline bool bio_has_data(struct bio *bio)55{56 if (bio &&57 bio->bi_iter.bi_size &&58 bio_op(bio) != REQ_OP_DISCARD &&59 bio_op(bio) != REQ_OP_SECURE_ERASE &&60 bio_op(bio) != REQ_OP_WRITE_ZEROES)61 return true;62 63 return false;64}65 66static inline bool bio_no_advance_iter(const struct bio *bio)67{68 return bio_op(bio) == REQ_OP_DISCARD ||69 bio_op(bio) == REQ_OP_SECURE_ERASE ||70 bio_op(bio) == REQ_OP_WRITE_ZEROES;71}72 73static inline void *bio_data(struct bio *bio)74{75 if (bio_has_data(bio))76 return page_address(bio_page(bio)) + bio_offset(bio);77 78 return NULL;79}80 81static inline bool bio_next_segment(const struct bio *bio,82 struct bvec_iter_all *iter)83{84 if (iter->idx >= bio->bi_vcnt)85 return false;86 87 bvec_advance(&bio->bi_io_vec[iter->idx], iter);88 return true;89}90 91/*92 * drivers should _never_ use the all version - the bio may have been split93 * before it got to the driver and the driver won't own all of it94 */95#define bio_for_each_segment_all(bvl, bio, iter) \96 for (bvl = bvec_init_iter_all(&iter); bio_next_segment((bio), &iter); )97 98static inline void bio_advance_iter(const struct bio *bio,99 struct bvec_iter *iter, unsigned int bytes)100{101 iter->bi_sector += bytes >> 9;102 103 if (bio_no_advance_iter(bio))104 iter->bi_size -= bytes;105 else106 bvec_iter_advance(bio->bi_io_vec, iter, bytes);107 /* TODO: It is reasonable to complete bio with error here. */108}109 110/* @bytes should be less or equal to bvec[i->bi_idx].bv_len */111static inline void bio_advance_iter_single(const struct bio *bio,112 struct bvec_iter *iter,113 unsigned int bytes)114{115 iter->bi_sector += bytes >> 9;116 117 if (bio_no_advance_iter(bio))118 iter->bi_size -= bytes;119 else120 bvec_iter_advance_single(bio->bi_io_vec, iter, bytes);121}122 123void __bio_advance(struct bio *, unsigned bytes);124 125/**126 * bio_advance - increment/complete a bio by some number of bytes127 * @bio: bio to advance128 * @nbytes: number of bytes to complete129 *130 * This updates bi_sector, bi_size and bi_idx; if the number of bytes to131 * complete doesn't align with a bvec boundary, then bv_len and bv_offset will132 * be updated on the last bvec as well.133 *134 * @bio will then represent the remaining, uncompleted portion of the io.135 */136static inline void bio_advance(struct bio *bio, unsigned int nbytes)137{138 if (nbytes == bio->bi_iter.bi_size) {139 bio->bi_iter.bi_size = 0;140 return;141 }142 __bio_advance(bio, nbytes);143}144 145#define __bio_for_each_segment(bvl, bio, iter, start) \146 for (iter = (start); \147 (iter).bi_size && \148 ((bvl = bio_iter_iovec((bio), (iter))), 1); \149 bio_advance_iter_single((bio), &(iter), (bvl).bv_len))150 151#define bio_for_each_segment(bvl, bio, iter) \152 __bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter)153 154#define __bio_for_each_bvec(bvl, bio, iter, start) \155 for (iter = (start); \156 (iter).bi_size && \157 ((bvl = mp_bvec_iter_bvec((bio)->bi_io_vec, (iter))), 1); \158 bio_advance_iter_single((bio), &(iter), (bvl).bv_len))159 160/* iterate over multi-page bvec */161#define bio_for_each_bvec(bvl, bio, iter) \162 __bio_for_each_bvec(bvl, bio, iter, (bio)->bi_iter)163 164/*165 * Iterate over all multi-page bvecs. Drivers shouldn't use this version for the166 * same reasons as bio_for_each_segment_all().167 */168#define bio_for_each_bvec_all(bvl, bio, i) \169 for (i = 0, bvl = bio_first_bvec_all(bio); \170 i < (bio)->bi_vcnt; i++, bvl++)171 172#define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)173 174static inline unsigned bio_segments(struct bio *bio)175{176 unsigned segs = 0;177 struct bio_vec bv;178 struct bvec_iter iter;179 180 /*181 * We special case discard/write same/write zeroes, because they182 * interpret bi_size differently:183 */184 185 switch (bio_op(bio)) {186 case REQ_OP_DISCARD:187 case REQ_OP_SECURE_ERASE:188 case REQ_OP_WRITE_ZEROES:189 return 0;190 default:191 break;192 }193 194 bio_for_each_segment(bv, bio, iter)195 segs++;196 197 return segs;198}199 200/*201 * get a reference to a bio, so it won't disappear. the intended use is202 * something like:203 *204 * bio_get(bio);205 * submit_bio(rw, bio);206 * if (bio->bi_flags ...)207 * do_something208 * bio_put(bio);209 *210 * without the bio_get(), it could potentially complete I/O before submit_bio211 * returns. and then bio would be freed memory when if (bio->bi_flags ...)212 * runs213 */214static inline void bio_get(struct bio *bio)215{216 bio->bi_flags |= (1 << BIO_REFFED);217 smp_mb__before_atomic();218 atomic_inc(&bio->__bi_cnt);219}220 221static inline void bio_cnt_set(struct bio *bio, unsigned int count)222{223 if (count != 1) {224 bio->bi_flags |= (1 << BIO_REFFED);225 smp_mb();226 }227 atomic_set(&bio->__bi_cnt, count);228}229 230static inline bool bio_flagged(struct bio *bio, unsigned int bit)231{232 return bio->bi_flags & (1U << bit);233}234 235static inline void bio_set_flag(struct bio *bio, unsigned int bit)236{237 bio->bi_flags |= (1U << bit);238}239 240static inline void bio_clear_flag(struct bio *bio, unsigned int bit)241{242 bio->bi_flags &= ~(1U << bit);243}244 245static inline struct bio_vec *bio_first_bvec_all(struct bio *bio)246{247 WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));248 return bio->bi_io_vec;249}250 251static inline struct page *bio_first_page_all(struct bio *bio)252{253 return bio_first_bvec_all(bio)->bv_page;254}255 256static inline struct folio *bio_first_folio_all(struct bio *bio)257{258 return page_folio(bio_first_page_all(bio));259}260 261static inline struct bio_vec *bio_last_bvec_all(struct bio *bio)262{263 WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));264 return &bio->bi_io_vec[bio->bi_vcnt - 1];265}266 267/**268 * struct folio_iter - State for iterating all folios in a bio.269 * @folio: The current folio we're iterating. NULL after the last folio.270 * @offset: The byte offset within the current folio.271 * @length: The number of bytes in this iteration (will not cross folio272 * boundary).273 */274struct folio_iter {275 struct folio *folio;276 size_t offset;277 size_t length;278 /* private: for use by the iterator */279 struct folio *_next;280 size_t _seg_count;281 int _i;282};283 284static inline void bio_first_folio(struct folio_iter *fi, struct bio *bio,285 int i)286{287 struct bio_vec *bvec = bio_first_bvec_all(bio) + i;288 289 if (unlikely(i >= bio->bi_vcnt)) {290 fi->folio = NULL;291 return;292 }293 294 fi->folio = page_folio(bvec->bv_page);295 fi->offset = bvec->bv_offset +296 PAGE_SIZE * (bvec->bv_page - &fi->folio->page);297 fi->_seg_count = bvec->bv_len;298 fi->length = min(folio_size(fi->folio) - fi->offset, fi->_seg_count);299 fi->_next = folio_next(fi->folio);300 fi->_i = i;301}302 303static inline void bio_next_folio(struct folio_iter *fi, struct bio *bio)304{305 fi->_seg_count -= fi->length;306 if (fi->_seg_count) {307 fi->folio = fi->_next;308 fi->offset = 0;309 fi->length = min(folio_size(fi->folio), fi->_seg_count);310 fi->_next = folio_next(fi->folio);311 } else {312 bio_first_folio(fi, bio, fi->_i + 1);313 }314}315 316/**317 * bio_for_each_folio_all - Iterate over each folio in a bio.318 * @fi: struct folio_iter which is updated for each folio.319 * @bio: struct bio to iterate over.320 */321#define bio_for_each_folio_all(fi, bio) \322 for (bio_first_folio(&fi, bio, 0); fi.folio; bio_next_folio(&fi, bio))323 324void bio_trim(struct bio *bio, sector_t offset, sector_t size);325extern struct bio *bio_split(struct bio *bio, int sectors,326 gfp_t gfp, struct bio_set *bs);327int bio_split_rw_at(struct bio *bio, const struct queue_limits *lim,328 unsigned *segs, unsigned max_bytes);329 330/**331 * bio_next_split - get next @sectors from a bio, splitting if necessary332 * @bio: bio to split333 * @sectors: number of sectors to split from the front of @bio334 * @gfp: gfp mask335 * @bs: bio set to allocate from336 *337 * Return: a bio representing the next @sectors of @bio - if the bio is smaller338 * than @sectors, returns the original bio unchanged.339 */340static inline struct bio *bio_next_split(struct bio *bio, int sectors,341 gfp_t gfp, struct bio_set *bs)342{343 if (sectors >= bio_sectors(bio))344 return bio;345 346 return bio_split(bio, sectors, gfp, bs);347}348 349enum {350 BIOSET_NEED_BVECS = BIT(0),351 BIOSET_NEED_RESCUER = BIT(1),352 BIOSET_PERCPU_CACHE = BIT(2),353};354extern int bioset_init(struct bio_set *, unsigned int, unsigned int, int flags);355extern void bioset_exit(struct bio_set *);356extern int biovec_init_pool(mempool_t *pool, int pool_entries);357 358struct bio *bio_alloc_bioset(struct block_device *bdev, unsigned short nr_vecs,359 blk_opf_t opf, gfp_t gfp_mask,360 struct bio_set *bs);361struct bio *bio_kmalloc(unsigned short nr_vecs, gfp_t gfp_mask);362extern void bio_put(struct bio *);363 364struct bio *bio_alloc_clone(struct block_device *bdev, struct bio *bio_src,365 gfp_t gfp, struct bio_set *bs);366int bio_init_clone(struct block_device *bdev, struct bio *bio,367 struct bio *bio_src, gfp_t gfp);368 369extern struct bio_set fs_bio_set;370 371static inline struct bio *bio_alloc(struct block_device *bdev,372 unsigned short nr_vecs, blk_opf_t opf, gfp_t gfp_mask)373{374 return bio_alloc_bioset(bdev, nr_vecs, opf, gfp_mask, &fs_bio_set);375}376 377void submit_bio(struct bio *bio);378 379extern void bio_endio(struct bio *);380 381static inline void bio_io_error(struct bio *bio)382{383 bio->bi_status = BLK_STS_IOERR;384 bio_endio(bio);385}386 387static inline void bio_wouldblock_error(struct bio *bio)388{389 bio_set_flag(bio, BIO_QUIET);390 bio->bi_status = BLK_STS_AGAIN;391 bio_endio(bio);392}393 394/*395 * Calculate number of bvec segments that should be allocated to fit data396 * pointed by @iter. If @iter is backed by bvec it's going to be reused397 * instead of allocating a new one.398 */399static inline int bio_iov_vecs_to_alloc(struct iov_iter *iter, int max_segs)400{401 if (iov_iter_is_bvec(iter))402 return 0;403 return iov_iter_npages(iter, max_segs);404}405 406struct request_queue;407 408extern int submit_bio_wait(struct bio *bio);409void bio_init(struct bio *bio, struct block_device *bdev, struct bio_vec *table,410 unsigned short max_vecs, blk_opf_t opf);411extern void bio_uninit(struct bio *);412void bio_reset(struct bio *bio, struct block_device *bdev, blk_opf_t opf);413void bio_chain(struct bio *, struct bio *);414 415int __must_check bio_add_page(struct bio *bio, struct page *page, unsigned len,416 unsigned off);417bool __must_check bio_add_folio(struct bio *bio, struct folio *folio,418 size_t len, size_t off);419extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,420 unsigned int, unsigned int);421int bio_add_zone_append_page(struct bio *bio, struct page *page,422 unsigned int len, unsigned int offset);423void __bio_add_page(struct bio *bio, struct page *page,424 unsigned int len, unsigned int off);425void bio_add_folio_nofail(struct bio *bio, struct folio *folio, size_t len,426 size_t off);427int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter);428void bio_iov_bvec_set(struct bio *bio, struct iov_iter *iter);429void __bio_release_pages(struct bio *bio, bool mark_dirty);430extern void bio_set_pages_dirty(struct bio *bio);431extern void bio_check_pages_dirty(struct bio *bio);432 433extern void bio_copy_data_iter(struct bio *dst, struct bvec_iter *dst_iter,434 struct bio *src, struct bvec_iter *src_iter);435extern void bio_copy_data(struct bio *dst, struct bio *src);436extern void bio_free_pages(struct bio *bio);437void guard_bio_eod(struct bio *bio);438void zero_fill_bio_iter(struct bio *bio, struct bvec_iter iter);439 440static inline void zero_fill_bio(struct bio *bio)441{442 zero_fill_bio_iter(bio, bio->bi_iter);443}444 445static inline void bio_release_pages(struct bio *bio, bool mark_dirty)446{447 if (bio_flagged(bio, BIO_PAGE_PINNED))448 __bio_release_pages(bio, mark_dirty);449}450 451#define bio_dev(bio) \452 disk_devt((bio)->bi_bdev->bd_disk)453 454#ifdef CONFIG_BLK_CGROUP455void bio_associate_blkg(struct bio *bio);456void bio_associate_blkg_from_css(struct bio *bio,457 struct cgroup_subsys_state *css);458void bio_clone_blkg_association(struct bio *dst, struct bio *src);459void blkcg_punt_bio_submit(struct bio *bio);460#else /* CONFIG_BLK_CGROUP */461static inline void bio_associate_blkg(struct bio *bio) { }462static inline void bio_associate_blkg_from_css(struct bio *bio,463 struct cgroup_subsys_state *css)464{ }465static inline void bio_clone_blkg_association(struct bio *dst,466 struct bio *src) { }467static inline void blkcg_punt_bio_submit(struct bio *bio)468{469 submit_bio(bio);470}471#endif /* CONFIG_BLK_CGROUP */472 473static inline void bio_set_dev(struct bio *bio, struct block_device *bdev)474{475 bio_clear_flag(bio, BIO_REMAPPED);476 if (bio->bi_bdev != bdev)477 bio_clear_flag(bio, BIO_BPS_THROTTLED);478 bio->bi_bdev = bdev;479 bio_associate_blkg(bio);480}481 482/*483 * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.484 *485 * A bio_list anchors a singly-linked list of bios chained through the bi_next486 * member of the bio. The bio_list also caches the last list member to allow487 * fast access to the tail.488 */489struct bio_list {490 struct bio *head;491 struct bio *tail;492};493 494static inline int bio_list_empty(const struct bio_list *bl)495{496 return bl->head == NULL;497}498 499static inline void bio_list_init(struct bio_list *bl)500{501 bl->head = bl->tail = NULL;502}503 504#define BIO_EMPTY_LIST { NULL, NULL }505 506#define bio_list_for_each(bio, bl) \507 for (bio = (bl)->head; bio; bio = bio->bi_next)508 509static inline unsigned bio_list_size(const struct bio_list *bl)510{511 unsigned sz = 0;512 struct bio *bio;513 514 bio_list_for_each(bio, bl)515 sz++;516 517 return sz;518}519 520static inline void bio_list_add(struct bio_list *bl, struct bio *bio)521{522 bio->bi_next = NULL;523 524 if (bl->tail)525 bl->tail->bi_next = bio;526 else527 bl->head = bio;528 529 bl->tail = bio;530}531 532static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)533{534 bio->bi_next = bl->head;535 536 bl->head = bio;537 538 if (!bl->tail)539 bl->tail = bio;540}541 542static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)543{544 if (!bl2->head)545 return;546 547 if (bl->tail)548 bl->tail->bi_next = bl2->head;549 else550 bl->head = bl2->head;551 552 bl->tail = bl2->tail;553}554 555static inline void bio_list_merge_init(struct bio_list *bl,556 struct bio_list *bl2)557{558 bio_list_merge(bl, bl2);559 bio_list_init(bl2);560}561 562static inline void bio_list_merge_head(struct bio_list *bl,563 struct bio_list *bl2)564{565 if (!bl2->head)566 return;567 568 if (bl->head)569 bl2->tail->bi_next = bl->head;570 else571 bl->tail = bl2->tail;572 573 bl->head = bl2->head;574}575 576static inline struct bio *bio_list_peek(struct bio_list *bl)577{578 return bl->head;579}580 581static inline struct bio *bio_list_pop(struct bio_list *bl)582{583 struct bio *bio = bl->head;584 585 if (bio) {586 bl->head = bl->head->bi_next;587 if (!bl->head)588 bl->tail = NULL;589 590 bio->bi_next = NULL;591 }592 593 return bio;594}595 596static inline struct bio *bio_list_get(struct bio_list *bl)597{598 struct bio *bio = bl->head;599 600 bl->head = bl->tail = NULL;601 602 return bio;603}604 605/*606 * Increment chain count for the bio. Make sure the CHAIN flag update607 * is visible before the raised count.608 */609static inline void bio_inc_remaining(struct bio *bio)610{611 bio_set_flag(bio, BIO_CHAIN);612 smp_mb__before_atomic();613 atomic_inc(&bio->__bi_remaining);614}615 616/*617 * bio_set is used to allow other portions of the IO system to618 * allocate their own private memory pools for bio and iovec structures.619 * These memory pools in turn all allocate from the bio_slab620 * and the bvec_slabs[].621 */622#define BIO_POOL_SIZE 2623 624struct bio_set {625 struct kmem_cache *bio_slab;626 unsigned int front_pad;627 628 /*629 * per-cpu bio alloc cache630 */631 struct bio_alloc_cache __percpu *cache;632 633 mempool_t bio_pool;634 mempool_t bvec_pool;635#if defined(CONFIG_BLK_DEV_INTEGRITY)636 mempool_t bio_integrity_pool;637 mempool_t bvec_integrity_pool;638#endif639 640 unsigned int back_pad;641 /*642 * Deadlock avoidance for stacking block drivers: see comments in643 * bio_alloc_bioset() for details644 */645 spinlock_t rescue_lock;646 struct bio_list rescue_list;647 struct work_struct rescue_work;648 struct workqueue_struct *rescue_workqueue;649 650 /*651 * Hot un-plug notifier for the per-cpu cache, if used652 */653 struct hlist_node cpuhp_dead;654};655 656static inline bool bioset_initialized(struct bio_set *bs)657{658 return bs->bio_slab != NULL;659}660 661/*662 * Mark a bio as polled. Note that for async polled IO, the caller must663 * expect -EWOULDBLOCK if we cannot allocate a request (or other resources).664 * We cannot block waiting for requests on polled IO, as those completions665 * must be found by the caller. This is different than IRQ driven IO, where666 * it's safe to wait for IO to complete.667 */668static inline void bio_set_polled(struct bio *bio, struct kiocb *kiocb)669{670 bio->bi_opf |= REQ_POLLED;671 if (kiocb->ki_flags & IOCB_NOWAIT)672 bio->bi_opf |= REQ_NOWAIT;673}674 675static inline void bio_clear_polled(struct bio *bio)676{677 bio->bi_opf &= ~REQ_POLLED;678}679 680struct bio *blk_next_bio(struct bio *bio, struct block_device *bdev,681 unsigned int nr_pages, blk_opf_t opf, gfp_t gfp);682struct bio *bio_chain_and_submit(struct bio *prev, struct bio *new);683 684struct bio *blk_alloc_discard_bio(struct block_device *bdev,685 sector_t *sector, sector_t *nr_sects, gfp_t gfp_mask);686 687#endif /* __LINUX_BIO_H */688