/* SPDX-License-Identifier: GPL-2.0 */ /* * Copyright (C) 2001 Jens Axboe <[email protected]> */ #ifndef __LINUX_BIO_H #define __LINUX_BIO_H #include <linux/mempool.h> /* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */ #include <linux/blk_types.h> #include <linux/uio.h> #define BIO_MAX_VECS … struct queue_limits; static inline unsigned int bio_max_segs(unsigned int nr_segs) { … } #define bio_prio(bio) … #define bio_set_prio(bio, prio) … #define bio_iter_iovec(bio, iter) … #define bio_iter_page(bio, iter) … #define bio_iter_len(bio, iter) … #define bio_iter_offset(bio, iter) … #define bio_page(bio) … #define bio_offset(bio) … #define bio_iovec(bio) … #define bvec_iter_sectors(iter) … #define bvec_iter_end_sector(iter) … #define bio_sectors(bio) … #define bio_end_sector(bio) … /* * Return the data direction, READ or WRITE. */ #define bio_data_dir(bio) … /* * Check whether this bio carries any data or not. A NULL bio is allowed. */ static inline bool bio_has_data(struct bio *bio) { … } static inline bool bio_no_advance_iter(const struct bio *bio) { … } static inline void *bio_data(struct bio *bio) { … } static inline bool bio_next_segment(const struct bio *bio, struct bvec_iter_all *iter) { … } /* * drivers should _never_ use the all version - the bio may have been split * before it got to the driver and the driver won't own all of it */ #define bio_for_each_segment_all(bvl, bio, iter) … static inline void bio_advance_iter(const struct bio *bio, struct bvec_iter *iter, unsigned int bytes) { … } /* @bytes should be less or equal to bvec[i->bi_idx].bv_len */ static inline void bio_advance_iter_single(const struct bio *bio, struct bvec_iter *iter, unsigned int bytes) { … } void __bio_advance(struct bio *, unsigned bytes); /** * bio_advance - increment/complete a bio by some number of bytes * @bio: bio to advance * @nbytes: number of bytes to complete * * This updates bi_sector, bi_size and bi_idx; if the number of bytes to * complete doesn't align with a bvec boundary, then bv_len and bv_offset will * be updated on the last bvec as well. * * @bio will then represent the remaining, uncompleted portion of the io. */ static inline void bio_advance(struct bio *bio, unsigned int nbytes) { … } #define __bio_for_each_segment(bvl, bio, iter, start) … #define bio_for_each_segment(bvl, bio, iter) … #define __bio_for_each_bvec(bvl, bio, iter, start) … /* iterate over multi-page bvec */ #define bio_for_each_bvec(bvl, bio, iter) … /* * Iterate over all multi-page bvecs. Drivers shouldn't use this version for the * same reasons as bio_for_each_segment_all(). */ #define bio_for_each_bvec_all(bvl, bio, i) … #define bio_iter_last(bvec, iter) … static inline unsigned bio_segments(struct bio *bio) { … } /* * get a reference to a bio, so it won't disappear. the intended use is * something like: * * bio_get(bio); * submit_bio(rw, bio); * if (bio->bi_flags ...) * do_something * bio_put(bio); * * without the bio_get(), it could potentially complete I/O before submit_bio * returns. and then bio would be freed memory when if (bio->bi_flags ...) * runs */ static inline void bio_get(struct bio *bio) { … } static inline void bio_cnt_set(struct bio *bio, unsigned int count) { … } static inline bool bio_flagged(struct bio *bio, unsigned int bit) { … } static inline void bio_set_flag(struct bio *bio, unsigned int bit) { … } static inline void bio_clear_flag(struct bio *bio, unsigned int bit) { … } static inline struct bio_vec *bio_first_bvec_all(struct bio *bio) { … } static inline struct page *bio_first_page_all(struct bio *bio) { … } static inline struct folio *bio_first_folio_all(struct bio *bio) { … } static inline struct bio_vec *bio_last_bvec_all(struct bio *bio) { … } /** * struct folio_iter - State for iterating all folios in a bio. * @folio: The current folio we're iterating. NULL after the last folio. * @offset: The byte offset within the current folio. * @length: The number of bytes in this iteration (will not cross folio * boundary). */ struct folio_iter { … }; static inline void bio_first_folio(struct folio_iter *fi, struct bio *bio, int i) { … } static inline void bio_next_folio(struct folio_iter *fi, struct bio *bio) { … } /** * bio_for_each_folio_all - Iterate over each folio in a bio. * @fi: struct folio_iter which is updated for each folio. * @bio: struct bio to iterate over. */ #define bio_for_each_folio_all(fi, bio) … void bio_trim(struct bio *bio, sector_t offset, sector_t size); extern struct bio *bio_split(struct bio *bio, int sectors, gfp_t gfp, struct bio_set *bs); int bio_split_rw_at(struct bio *bio, const struct queue_limits *lim, unsigned *segs, unsigned max_bytes); /** * bio_next_split - get next @sectors from a bio, splitting if necessary * @bio: bio to split * @sectors: number of sectors to split from the front of @bio * @gfp: gfp mask * @bs: bio set to allocate from * * Return: a bio representing the next @sectors of @bio - if the bio is smaller * than @sectors, returns the original bio unchanged. */ static inline struct bio *bio_next_split(struct bio *bio, int sectors, gfp_t gfp, struct bio_set *bs) { … } enum { … }; extern int bioset_init(struct bio_set *, unsigned int, unsigned int, int flags); extern void bioset_exit(struct bio_set *); extern int biovec_init_pool(mempool_t *pool, int pool_entries); struct bio *bio_alloc_bioset(struct block_device *bdev, unsigned short nr_vecs, blk_opf_t opf, gfp_t gfp_mask, struct bio_set *bs); struct bio *bio_kmalloc(unsigned short nr_vecs, gfp_t gfp_mask); extern void bio_put(struct bio *); struct bio *bio_alloc_clone(struct block_device *bdev, struct bio *bio_src, gfp_t gfp, struct bio_set *bs); int bio_init_clone(struct block_device *bdev, struct bio *bio, struct bio *bio_src, gfp_t gfp); extern struct bio_set fs_bio_set; static inline struct bio *bio_alloc(struct block_device *bdev, unsigned short nr_vecs, blk_opf_t opf, gfp_t gfp_mask) { … } void submit_bio(struct bio *bio); extern void bio_endio(struct bio *); static inline void bio_io_error(struct bio *bio) { … } static inline void bio_wouldblock_error(struct bio *bio) { … } /* * Calculate number of bvec segments that should be allocated to fit data * pointed by @iter. If @iter is backed by bvec it's going to be reused * instead of allocating a new one. */ static inline int bio_iov_vecs_to_alloc(struct iov_iter *iter, int max_segs) { … } struct request_queue; extern int submit_bio_wait(struct bio *bio); void bio_init(struct bio *bio, struct block_device *bdev, struct bio_vec *table, unsigned short max_vecs, blk_opf_t opf); extern void bio_uninit(struct bio *); void bio_reset(struct bio *bio, struct block_device *bdev, blk_opf_t opf); void bio_chain(struct bio *, struct bio *); int __must_check bio_add_page(struct bio *bio, struct page *page, unsigned len, unsigned off); bool __must_check bio_add_folio(struct bio *bio, struct folio *folio, size_t len, size_t off); extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *, unsigned int, unsigned int); int bio_add_zone_append_page(struct bio *bio, struct page *page, unsigned int len, unsigned int offset); void __bio_add_page(struct bio *bio, struct page *page, unsigned int len, unsigned int off); void bio_add_folio_nofail(struct bio *bio, struct folio *folio, size_t len, size_t off); int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter); void bio_iov_bvec_set(struct bio *bio, struct iov_iter *iter); void __bio_release_pages(struct bio *bio, bool mark_dirty); extern void bio_set_pages_dirty(struct bio *bio); extern void bio_check_pages_dirty(struct bio *bio); extern void bio_copy_data_iter(struct bio *dst, struct bvec_iter *dst_iter, struct bio *src, struct bvec_iter *src_iter); extern void bio_copy_data(struct bio *dst, struct bio *src); extern void bio_free_pages(struct bio *bio); void guard_bio_eod(struct bio *bio); void zero_fill_bio_iter(struct bio *bio, struct bvec_iter iter); static inline void zero_fill_bio(struct bio *bio) { … } static inline void bio_release_pages(struct bio *bio, bool mark_dirty) { … } #define bio_dev(bio) … #ifdef CONFIG_BLK_CGROUP void bio_associate_blkg(struct bio *bio); void bio_associate_blkg_from_css(struct bio *bio, struct cgroup_subsys_state *css); void bio_clone_blkg_association(struct bio *dst, struct bio *src); void blkcg_punt_bio_submit(struct bio *bio); #else /* CONFIG_BLK_CGROUP */ static inline void bio_associate_blkg(struct bio *bio) { } static inline void bio_associate_blkg_from_css(struct bio *bio, struct cgroup_subsys_state *css) { } static inline void bio_clone_blkg_association(struct bio *dst, struct bio *src) { } static inline void blkcg_punt_bio_submit(struct bio *bio) { submit_bio(bio); } #endif /* CONFIG_BLK_CGROUP */ static inline void bio_set_dev(struct bio *bio, struct block_device *bdev) { … } /* * BIO list management for use by remapping drivers (e.g. DM or MD) and loop. * * A bio_list anchors a singly-linked list of bios chained through the bi_next * member of the bio. The bio_list also caches the last list member to allow * fast access to the tail. */ struct bio_list { … }; static inline int bio_list_empty(const struct bio_list *bl) { … } static inline void bio_list_init(struct bio_list *bl) { … } #define BIO_EMPTY_LIST … #define bio_list_for_each(bio, bl) … static inline unsigned bio_list_size(const struct bio_list *bl) { … } static inline void bio_list_add(struct bio_list *bl, struct bio *bio) { … } static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio) { … } static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2) { … } static inline void bio_list_merge_init(struct bio_list *bl, struct bio_list *bl2) { … } static inline void bio_list_merge_head(struct bio_list *bl, struct bio_list *bl2) { … } static inline struct bio *bio_list_peek(struct bio_list *bl) { … } static inline struct bio *bio_list_pop(struct bio_list *bl) { … } static inline struct bio *bio_list_get(struct bio_list *bl) { … } /* * Increment chain count for the bio. Make sure the CHAIN flag update * is visible before the raised count. */ static inline void bio_inc_remaining(struct bio *bio) { … } /* * bio_set is used to allow other portions of the IO system to * allocate their own private memory pools for bio and iovec structures. * These memory pools in turn all allocate from the bio_slab * and the bvec_slabs[]. */ #define BIO_POOL_SIZE … struct bio_set { … }; static inline bool bioset_initialized(struct bio_set *bs) { … } /* * Mark a bio as polled. Note that for async polled IO, the caller must * expect -EWOULDBLOCK if we cannot allocate a request (or other resources). * We cannot block waiting for requests on polled IO, as those completions * must be found by the caller. This is different than IRQ driven IO, where * it's safe to wait for IO to complete. */ static inline void bio_set_polled(struct bio *bio, struct kiocb *kiocb) { … } static inline void bio_clear_polled(struct bio *bio) { … } struct bio *blk_next_bio(struct bio *bio, struct block_device *bdev, unsigned int nr_pages, blk_opf_t opf, gfp_t gfp); struct bio *bio_chain_and_submit(struct bio *prev, struct bio *new); struct bio *blk_alloc_discard_bio(struct block_device *bdev, sector_t *sector, sector_t *nr_sects, gfp_t gfp_mask); #endif /* __LINUX_BIO_H */
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