/* * 2.5 block I/O model * * Copyright (C) 2001 Jens Axboe * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public Licens * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111- */ #ifndef __LINUX_BIO_H #define __LINUX_BIO_H #include #include #include #include #ifdef CONFIG_BLOCK #include /* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */ #include #define BIO_DEBUG #ifdef BIO_DEBUG #define BIO_BUG_ON BUG_ON #else #define BIO_BUG_ON #endif #define BIO_MAX_PAGES 256 #define BIO_MAX_SIZE (BIO_MAX_PAGES << PAGE_SHIFT) #define BIO_MAX_SECTORS (BIO_MAX_SIZE >> 9) #define bio_prio(bio) (bio)->bi_ioprio #define bio_set_prio(bio, prio) ((bio)->bi_ioprio = prio) /* * various member access, note that bio_data should of course not be used * on highmem page vectors */ #define __bvec_iter_bvec(bvec, iter) (&(bvec)[(iter).bi_idx]) #define bvec_iter_page(bvec, iter) \ (__bvec_iter_bvec((bvec), (iter))->bv_page) #define bvec_iter_len(bvec, iter) \ min((iter).bi_size, \ __bvec_iter_bvec((bvec), (iter))->bv_len - (iter).bi_bvec_done) #define bvec_iter_offset(bvec, iter) \ (__bvec_iter_bvec((bvec), (iter))->bv_offset + (iter).bi_bvec_done) #define bvec_iter_bvec(bvec, iter) \ ((struct bio_vec) { \ .bv_page = bvec_iter_page((bvec), (iter)), \ .bv_len = bvec_iter_len((bvec), (iter)), \ .bv_offset = bvec_iter_offset((bvec), (iter)), \ }) #define bio_iter_iovec(bio, iter) \ bvec_iter_bvec((bio)->bi_io_vec, (iter)) #define bio_iter_page(bio, iter) \ bvec_iter_page((bio)->bi_io_vec, (iter)) #define bio_iter_len(bio, iter) \ bvec_iter_len((bio)->bi_io_vec, (iter)) #define bio_iter_offset(bio, iter) \ bvec_iter_offset((bio)->bi_io_vec, (iter)) #define bio_page(bio) bio_iter_page((bio), (bio)->bi_iter) #define bio_offset(bio) bio_iter_offset((bio), (bio)->bi_iter) #define bio_iovec(bio) bio_iter_iovec((bio), (bio)->bi_iter) #define bio_multiple_segments(bio) \ ((bio)->bi_iter.bi_size != bio_iovec(bio).bv_len) #define bio_sectors(bio) ((bio)->bi_iter.bi_size >> 9) #define bio_end_sector(bio) ((bio)->bi_iter.bi_sector + bio_sectors((bio))) /* * Check whether this bio carries any data or not. A NULL bio is allowed. */ static inline bool bio_has_data(struct bio *bio) { if (bio && bio->bi_iter.bi_size && bio_op(bio) != REQ_OP_DISCARD) return true; return false; } static inline bool bio_no_advance_iter(struct bio *bio) { return bio_op(bio) == REQ_OP_DISCARD || bio_op(bio) == REQ_OP_WRITE_SAME; } static inline bool bio_is_rw(struct bio *bio) { if (!bio_has_data(bio)) return false; if (bio_no_advance_iter(bio)) return false; return true; } static inline bool bio_mergeable(struct bio *bio) { if (bio->bi_rw & REQ_NOMERGE_FLAGS) return false; return true; } static inline unsigned int bio_cur_bytes(struct bio *bio) { if (bio_has_data(bio)) return bio_iovec(bio).bv_len; else /* dataless requests such as discard */ return bio->bi_iter.bi_size; } static inline void *bio_data(struct bio *bio) { if (bio_has_data(bio)) return page_address(bio_page(bio)) + bio_offset(bio); return NULL; } /* * will die */ #define bio_to_phys(bio) (page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio))) #define bvec_to_phys(bv) (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset) /* * queues that have highmem support enabled may still need to revert to * PIO transfers occasionally and thus map high pages temporarily. For * permanent PIO fall back, user is probably better off disabling highmem * I/O completely on that queue (see ide-dma for example) */ #define __bio_kmap_atomic(bio, iter) \ (kmap_atomic(bio_iter_iovec((bio), (iter)).bv_page) + \ bio_iter_iovec((bio), (iter)).bv_offset) #define __bio_kunmap_atomic(addr) kunmap_atomic(addr) /* * merge helpers etc */ /* Default implementation of BIOVEC_PHYS_MERGEABLE */ #define __BIOVEC_PHYS_MERGEABLE(vec1, vec2) \ ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2))) /* * allow arch override, for eg virtualized architectures (put in asm/io.h) */ #ifndef BIOVEC_PHYS_MERGEABLE #define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \ __BIOVEC_PHYS_MERGEABLE(vec1, vec2) #endif #define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \ (((addr1) | (mask)) == (((addr2) - 1) | (mask))) #define BIOVEC_SEG_BOUNDARY(q, b1, b2) \ __BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q))) /* * 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, i) \ for (i = 0, bvl = (bio)->bi_io_vec; i < (bio)->bi_vcnt; i++, bvl++) static inline void bvec_iter_advance(struct bio_vec *bv, struct bvec_iter *iter, unsigned bytes) { WARN_ONCE(bytes > iter->bi_size, "Attempted to advance past end of bvec iter\n"); while (bytes) { unsigned len = min(bytes, bvec_iter_len(bv, *iter)); bytes -= len; iter->bi_size -= len; iter->bi_bvec_done += len; if (iter->bi_bvec_done == __bvec_iter_bvec(bv, *iter)->bv_len) { iter->bi_bvec_done = 0; iter->bi_idx++; } } } #define for_each_bvec(bvl, bio_vec, iter, start) \ for (iter = (start); \ (iter).bi_size && \ ((bvl = bvec_iter_bvec((bio_vec), (iter))), 1); \ bvec_iter_advance((bio_vec), &(iter), (bvl).bv_len)) static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter, unsigned bytes) { iter->bi_sector += bytes >> 9; if (bio_no_advance_iter(bio)) iter->bi_size -= bytes; else bvec_iter_advance(bio->bi_io_vec, iter, bytes); } #define __bio_for_each_segment(bvl, bio, iter, start) \ for (iter = (start); \ (iter).bi_size && \ ((bvl = bio_iter_iovec((bio), (iter))), 1); \ bio_advance_iter((bio), &(iter), (bvl).bv_len)) #define bio_for_each_segment(bvl, bio, iter) \ __bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter) #define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len) static inline unsigned bio_segments(struct bio *bio) { unsigned segs = 0; struct bio_vec bv; struct bvec_iter iter; /* * We special case discard/write same, because they interpret bi_size * differently: */ if (bio_op(bio) == REQ_OP_DISCARD) return 1; if (bio_op(bio) == REQ_OP_WRITE_SAME) return 1; bio_for_each_segment(bv, bio, iter) segs++; return segs; } /* * 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) { bio->bi_flags |= (1 << BIO_REFFED); smp_mb__before_atomic(); atomic_inc(&bio->__bi_cnt); } static inline void bio_cnt_set(struct bio *bio, unsigned int count) { if (count != 1) { bio->bi_flags |= (1 << BIO_REFFED); smp_mb__before_atomic(); } atomic_set(&bio->__bi_cnt, count); } static inline bool bio_flagged(struct bio *bio, unsigned int bit) { return (bio->bi_flags & (1U << bit)) != 0; } static inline void bio_set_flag(struct bio *bio, unsigned int bit) { bio->bi_flags |= (1U << bit); } static inline void bio_clear_flag(struct bio *bio, unsigned int bit) { bio->bi_flags &= ~(1U << bit); } static inline void bio_get_first_bvec(struct bio *bio, struct bio_vec *bv) { *bv = bio_iovec(bio); } static inline void bio_get_last_bvec(struct bio *bio, struct bio_vec *bv) { struct bvec_iter iter = bio->bi_iter; int idx; if (unlikely(!bio_multiple_segments(bio))) { *bv = bio_iovec(bio); return; } bio_advance_iter(bio, &iter, iter.bi_size); if (!iter.bi_bvec_done) idx = iter.bi_idx - 1; else /* in the middle of bvec */ idx = iter.bi_idx; *bv = bio->bi_io_vec[idx]; /* * iter.bi_bvec_done records actual length of the last bvec * if this bio ends in the middle of one io vector */ if (iter.bi_bvec_done) bv->bv_len = iter.bi_bvec_done; } enum bip_flags { BIP_BLOCK_INTEGRITY = 1 << 0, /* block layer owns integrity data */ BIP_MAPPED_INTEGRITY = 1 << 1, /* ref tag has been remapped */ BIP_CTRL_NOCHECK = 1 << 2, /* disable HBA integrity checking */ BIP_DISK_NOCHECK = 1 << 3, /* disable disk integrity checking */ BIP_IP_CHECKSUM = 1 << 4, /* IP checksum */ }; /* * bio integrity payload */ struct bio_integrity_payload { struct bio *bip_bio; /* parent bio */ struct bvec_iter bip_iter; bio_end_io_t *bip_end_io; /* saved I/O completion fn */ unsigned short bip_slab; /* slab the bip came from */ unsigned short bip_vcnt; /* # of integrity bio_vecs */ unsigned short bip_max_vcnt; /* integrity bio_vec slots */ unsigned short bip_flags; /* control flags */ struct work_struct bip_work; /* I/O completion */ struct bio_vec *bip_vec; struct bio_vec bip_inline_vecs[0];/* embedded bvec array */ }; #if defined(CONFIG_BLK_DEV_INTEGRITY) static inline struct bio_integrity_payload *bio_integrity(struct bio *bio) { if (bio->bi_rw & REQ_INTEGRITY) return bio->bi_integrity; return NULL; } static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag) { struct bio_integrity_payload *bip = bio_integrity(bio); if (bip) return bip->bip_flags & flag; return false; } static inline sector_t bip_get_seed(struct bio_integrity_payload *bip) { return bip->bip_iter.bi_sector; } static inline void bip_set_seed(struct bio_integrity_payload *bip, sector_t seed) { bip->bip_iter.bi_sector = seed; } #endif /* CONFIG_BLK_DEV_INTEGRITY */ extern void bio_trim(struct bio *bio, int offset, int size); extern struct bio *bio_split(struct bio *bio, int sectors, gfp_t gfp, struct bio_set *bs); /** * 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 * * Returns 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) { if (sectors >= bio_sectors(bio)) return bio; return bio_split(bio, sectors, gfp, bs); } extern struct bio_set *bioset_create(unsigned int, unsigned int); extern struct bio_set *bioset_create_nobvec(unsigned int, unsigned int); extern void bioset_free(struct bio_set *); extern mempool_t *biovec_create_pool(int pool_entries); extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *); extern void bio_put(struct bio *); extern void __bio_clone_fast(struct bio *, struct bio *); extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *); extern struct bio *bio_clone_bioset(struct bio *, gfp_t, struct bio_set *bs); extern struct bio_set *fs_bio_set; static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs) { return bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set); } static inline struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask) { return bio_clone_bioset(bio, gfp_mask, fs_bio_set); } static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs) { return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL); } static inline struct bio *bio_clone_kmalloc(struct bio *bio, gfp_t gfp_mask) { return bio_clone_bioset(bio, gfp_mask, NULL); } extern void bio_endio(struct bio *); static inline void bio_io_error(struct bio *bio) { bio->bi_error = -EIO; bio_endio(bio); } struct request_queue; extern int bio_phys_segments(struct request_queue *, struct bio *); extern int submit_bio_wait(struct bio *bio); extern void bio_advance(struct bio *, unsigned); extern void bio_init(struct bio *); extern void bio_reset(struct bio *); void bio_chain(struct bio *, struct bio *); extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int); extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *, unsigned int, unsigned int); struct rq_map_data; extern struct bio *bio_map_user_iov(struct request_queue *, const struct iov_iter *, gfp_t); extern void bio_unmap_user(struct bio *); extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int, gfp_t); extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int, gfp_t, int); extern void bio_set_pages_dirty(struct bio *bio); extern void bio_check_pages_dirty(struct bio *bio); void generic_start_io_acct(int rw, unsigned long sectors, struct hd_struct *part); void generic_end_io_acct(int rw, struct hd_struct *part, unsigned long start_time); #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform" #endif #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE extern void bio_flush_dcache_pages(struct bio *bi); #else static inline void bio_flush_dcache_pages(struct bio *bi) { } #endif extern void bio_copy_data(struct bio *dst, struct bio *src); extern int bio_alloc_pages(struct bio *bio, gfp_t gfp); extern struct bio *bio_copy_user_iov(struct request_queue *, struct rq_map_data *, const struct iov_iter *, gfp_t); extern int bio_uncopy_user(struct bio *); void zero_fill_bio(struct bio *bio); extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *); extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int); extern unsigned int bvec_nr_vecs(unsigned short idx); #ifdef CONFIG_BLK_CGROUP int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css); int bio_associate_current(struct bio *bio); void bio_disassociate_task(struct bio *bio); #else /* CONFIG_BLK_CGROUP */ static inline int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css) { return 0; } static inline int bio_associate_current(struct bio *bio) { return -ENOENT; } static inline void bio_disassociate_task(struct bio *bio) { } #endif /* CONFIG_BLK_CGROUP */ #ifdef CONFIG_HIGHMEM /* * remember never ever reenable interrupts between a bvec_kmap_irq and * bvec_kunmap_irq! */ static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags) { unsigned long addr; /* * might not be a highmem page, but the preempt/irq count * balancing is a lot nicer this way */ local_irq_save(*flags); addr = (unsigned long) kmap_atomic(bvec->bv_page); BUG_ON(addr & ~PAGE_MASK); return (char *) addr + bvec->bv_offset; } static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags) { unsigned long ptr = (unsigned long) buffer & PAGE_MASK; kunmap_atomic((void *) ptr); local_irq_restore(*flags); } #else static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags) { return page_address(bvec->bv_page) + bvec->bv_offset; } static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags) { *flags = 0; } #endif static inline char *__bio_kmap_irq(struct bio *bio, struct bvec_iter iter, unsigned long *flags) { return bvec_kmap_irq(&bio_iter_iovec(bio, iter), flags); } #define __bio_kunmap_irq(buf, flags) bvec_kunmap_irq(buf, flags) #define bio_kmap_irq(bio, flags) \ __bio_kmap_irq((bio), (bio)->bi_iter, (flags)) #define bio_kunmap_irq(buf,flags) __bio_kunmap_irq(buf, flags) /* * 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 { struct bio *head; struct bio *tail; }; static inline int bio_list_empty(const struct bio_list *bl) { return bl->head == NULL; } static inline void bio_list_init(struct bio_list *bl) { bl->head = bl->tail = NULL; } #define BIO_EMPTY_LIST { NULL, NULL } #define bio_list_for_each(bio, bl) \ for (bio = (bl)->head; bio; bio = bio->bi_next) static inline unsigned bio_list_size(const struct bio_list *bl) { unsigned sz = 0; struct bio *bio; bio_list_for_each(bio, bl) sz++; return sz; } static inline void bio_list_add(struct bio_list *bl, struct bio *bio) { bio->bi_next = NULL; if (bl->tail) bl->tail->bi_next = bio; else bl->head = bio; bl->tail = bio; } static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio) { bio->bi_next = bl->head; bl->head = bio; if (!bl->tail) bl->tail = bio; } static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2) { if (!bl2->head) return; if (bl->tail) bl->tail->bi_next = bl2->head; else bl->head = bl2->head; bl->tail = bl2->tail; } static inline void bio_list_merge_head(struct bio_list *bl, struct bio_list *bl2) { if (!bl2->head) return; if (bl->head) bl2->tail->bi_next = bl->head; else bl->tail = bl2->tail; bl->head = bl2->head; } static inline struct bio *bio_list_peek(struct bio_list *bl) { return bl->head; } static inline struct bio *bio_list_pop(struct bio_list *bl) { struct bio *bio = bl->head; if (bio) { bl->head = bl->head->bi_next; if (!bl->head) bl->tail = NULL; bio->bi_next = NULL; } return bio; } static inline struct bio *bio_list_get(struct bio_list *bl) { struct bio *bio = bl->head; bl->head = bl->tail = NULL; return bio; } /* * 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_flag(bio, BIO_CHAIN); smp_mb__before_atomic(); atomic_inc(&bio->__bi_remaining); } /* * 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 2 #define BIOVEC_NR_POOLS 6 #define BIOVEC_MAX_IDX (BIOVEC_NR_POOLS - 1) struct bio_set { struct kmem_cache *bio_slab; unsigned int front_pad; mempool_t *bio_pool; mempool_t *bvec_pool; #if defined(CONFIG_BLK_DEV_INTEGRITY) mempool_t *bio_integrity_pool; mempool_t *bvec_integrity_pool; #endif /* * Deadlock avoidance for stacking block drivers: see comments in * bio_alloc_bioset() for details */ spinlock_t rescue_lock; struct bio_list rescue_list; struct work_struct rescue_work; struct workqueue_struct *rescue_workqueue; }; struct biovec_slab { int nr_vecs; char *name; struct kmem_cache *slab; }; /* * a small number of entries is fine, not going to be performance critical. * basically we just need to survive */ #define BIO_SPLIT_ENTRIES 2 #if defined(CONFIG_BLK_DEV_INTEGRITY) #define bip_for_each_vec(bvl, bip, iter) \ for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter) #define bio_for_each_integrity_vec(_bvl, _bio, _iter) \ for_each_bio(_bio) \ bip_for_each_vec(_bvl, _bio->bi_integrity, _iter) extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int); extern void bio_integrity_free(struct bio *); extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int); extern bool bio_integrity_enabled(struct bio *bio); extern int bio_integrity_prep(struct bio *); extern void bio_integrity_endio(struct bio *); extern void bio_integrity_advance(struct bio *, unsigned int); extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int); extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t); extern int bioset_integrity_create(struct bio_set *, int); extern void bioset_integrity_free(struct bio_set *); extern void bio_integrity_init(void); #else /* CONFIG_BLK_DEV_INTEGRITY */ static inline void *bio_integrity(struct bio *bio) { return NULL; } static inline bool bio_integrity_enabled(struct bio *bio) { return false; } static inline int bioset_integrity_create(struct bio_set *bs, int pool_size) { return 0; } static inline void bioset_integrity_free (struct bio_set *bs) { return; } static inline int bio_integrity_prep(struct bio *bio) { return 0; } static inline void bio_integrity_free(struct bio *bio) { return; } static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src, gfp_t gfp_mask) { return 0; } static inline void bio_integrity_advance(struct bio *bio, unsigned int bytes_done) { return; } static inline void bio_integrity_trim(struct bio *bio, unsigned int offset, unsigned int sectors) { return; } static inline void bio_integrity_init(void) { return; } static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag) { return false; } static inline void *bio_integrity_alloc(struct bio * bio, gfp_t gfp, unsigned int nr) { return ERR_PTR(-EINVAL); } static inline int bio_integrity_add_page(struct bio *bio, struct page *page, unsigned int len, unsigned int offset) { return 0; } #endif /* CONFIG_BLK_DEV_INTEGRITY */ #endif /* CONFIG_BLOCK */ #endif /* __LINUX_BIO_H */