| /* |
| * 2.5 block I/O model |
| * |
| * Copyright (C) 2001 Jens Axboe <axboe@suse.de> |
| * |
| * 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 <linux/highmem.h> |
| #include <linux/mempool.h> |
| #include <linux/ioprio.h> |
| |
| #ifdef CONFIG_BLOCK |
| |
| #include <asm/io.h> |
| |
| #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_CACHE_SHIFT) |
| #define BIO_MAX_SECTORS (BIO_MAX_SIZE >> 9) |
| |
| /* |
| * was unsigned short, but we might as well be ready for > 64kB I/O pages |
| */ |
| struct bio_vec { |
| struct page *bv_page; |
| unsigned int bv_len; |
| unsigned int bv_offset; |
| }; |
| |
| struct bio_set; |
| struct bio; |
| struct bio_integrity_payload; |
| typedef void (bio_end_io_t) (struct bio *, int); |
| typedef void (bio_destructor_t) (struct bio *); |
| |
| /* |
| * main unit of I/O for the block layer and lower layers (ie drivers and |
| * stacking drivers) |
| */ |
| struct bio { |
| sector_t bi_sector; /* device address in 512 byte |
| sectors */ |
| struct bio *bi_next; /* request queue link */ |
| struct block_device *bi_bdev; |
| unsigned long bi_flags; /* status, command, etc */ |
| unsigned long bi_rw; /* bottom bits READ/WRITE, |
| * top bits priority |
| */ |
| |
| unsigned short bi_vcnt; /* how many bio_vec's */ |
| unsigned short bi_idx; /* current index into bvl_vec */ |
| |
| /* Number of segments in this BIO after |
| * physical address coalescing is performed. |
| */ |
| unsigned int bi_phys_segments; |
| |
| unsigned int bi_size; /* residual I/O count */ |
| |
| /* |
| * To keep track of the max segment size, we account for the |
| * sizes of the first and last mergeable segments in this bio. |
| */ |
| unsigned int bi_seg_front_size; |
| unsigned int bi_seg_back_size; |
| |
| unsigned int bi_max_vecs; /* max bvl_vecs we can hold */ |
| |
| unsigned int bi_comp_cpu; /* completion CPU */ |
| |
| atomic_t bi_cnt; /* pin count */ |
| |
| struct bio_vec *bi_io_vec; /* the actual vec list */ |
| |
| bio_end_io_t *bi_end_io; |
| |
| void *bi_private; |
| #if defined(CONFIG_BLK_DEV_INTEGRITY) |
| struct bio_integrity_payload *bi_integrity; /* data integrity */ |
| #endif |
| |
| bio_destructor_t *bi_destructor; /* destructor */ |
| }; |
| |
| /* |
| * bio flags |
| */ |
| #define BIO_UPTODATE 0 /* ok after I/O completion */ |
| #define BIO_RW_BLOCK 1 /* RW_AHEAD set, and read/write would block */ |
| #define BIO_EOF 2 /* out-out-bounds error */ |
| #define BIO_SEG_VALID 3 /* bi_phys_segments valid */ |
| #define BIO_CLONED 4 /* doesn't own data */ |
| #define BIO_BOUNCED 5 /* bio is a bounce bio */ |
| #define BIO_USER_MAPPED 6 /* contains user pages */ |
| #define BIO_EOPNOTSUPP 7 /* not supported */ |
| #define BIO_CPU_AFFINE 8 /* complete bio on same CPU as submitted */ |
| #define BIO_NULL_MAPPED 9 /* contains invalid user pages */ |
| #define BIO_FS_INTEGRITY 10 /* fs owns integrity data, not block layer */ |
| #define BIO_QUIET 11 /* Make BIO Quiet */ |
| #define bio_flagged(bio, flag) ((bio)->bi_flags & (1 << (flag))) |
| |
| /* |
| * top 4 bits of bio flags indicate the pool this bio came from |
| */ |
| #define BIO_POOL_BITS (4) |
| #define BIO_POOL_OFFSET (BITS_PER_LONG - BIO_POOL_BITS) |
| #define BIO_POOL_MASK (1UL << BIO_POOL_OFFSET) |
| #define BIO_POOL_IDX(bio) ((bio)->bi_flags >> BIO_POOL_OFFSET) |
| |
| /* |
| * bio bi_rw flags |
| * |
| * bit 0 -- data direction |
| * If not set, bio is a read from device. If set, it's a write to device. |
| * bit 1 -- rw-ahead when set |
| * bit 2 -- barrier |
| * Insert a serialization point in the IO queue, forcing previously |
| * submitted IO to be completed before this oen is issued. |
| * bit 3 -- synchronous I/O hint: the block layer will unplug immediately |
| * Note that this does NOT indicate that the IO itself is sync, just |
| * that the block layer will not postpone issue of this IO by plugging. |
| * bit 4 -- metadata request |
| * Used for tracing to differentiate metadata and data IO. May also |
| * get some preferential treatment in the IO scheduler |
| * bit 5 -- discard sectors |
| * Informs the lower level device that this range of sectors is no longer |
| * used by the file system and may thus be freed by the device. Used |
| * for flash based storage. |
| * bit 6 -- fail fast device errors |
| * bit 7 -- fail fast transport errors |
| * bit 8 -- fail fast driver errors |
| * Don't want driver retries for any fast fail whatever the reason. |
| */ |
| #define BIO_RW 0 /* Must match RW in req flags (blkdev.h) */ |
| #define BIO_RW_AHEAD 1 /* Must match FAILFAST in req flags */ |
| #define BIO_RW_BARRIER 2 |
| #define BIO_RW_SYNC 3 |
| #define BIO_RW_META 4 |
| #define BIO_RW_DISCARD 5 |
| #define BIO_RW_FAILFAST_DEV 6 |
| #define BIO_RW_FAILFAST_TRANSPORT 7 |
| #define BIO_RW_FAILFAST_DRIVER 8 |
| |
| /* |
| * upper 16 bits of bi_rw define the io priority of this bio |
| */ |
| #define BIO_PRIO_SHIFT (8 * sizeof(unsigned long) - IOPRIO_BITS) |
| #define bio_prio(bio) ((bio)->bi_rw >> BIO_PRIO_SHIFT) |
| #define bio_prio_valid(bio) ioprio_valid(bio_prio(bio)) |
| |
| #define bio_set_prio(bio, prio) do { \ |
| WARN_ON(prio >= (1 << IOPRIO_BITS)); \ |
| (bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1); \ |
| (bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT); \ |
| } while (0) |
| |
| /* |
| * various member access, note that bio_data should of course not be used |
| * on highmem page vectors |
| */ |
| #define bio_iovec_idx(bio, idx) (&((bio)->bi_io_vec[(idx)])) |
| #define bio_iovec(bio) bio_iovec_idx((bio), (bio)->bi_idx) |
| #define bio_page(bio) bio_iovec((bio))->bv_page |
| #define bio_offset(bio) bio_iovec((bio))->bv_offset |
| #define bio_segments(bio) ((bio)->bi_vcnt - (bio)->bi_idx) |
| #define bio_sectors(bio) ((bio)->bi_size >> 9) |
| #define bio_barrier(bio) ((bio)->bi_rw & (1 << BIO_RW_BARRIER)) |
| #define bio_sync(bio) ((bio)->bi_rw & (1 << BIO_RW_SYNC)) |
| #define bio_failfast_dev(bio) ((bio)->bi_rw & (1 << BIO_RW_FAILFAST_DEV)) |
| #define bio_failfast_transport(bio) \ |
| ((bio)->bi_rw & (1 << BIO_RW_FAILFAST_TRANSPORT)) |
| #define bio_failfast_driver(bio) ((bio)->bi_rw & (1 << BIO_RW_FAILFAST_DRIVER)) |
| #define bio_rw_ahead(bio) ((bio)->bi_rw & (1 << BIO_RW_AHEAD)) |
| #define bio_rw_meta(bio) ((bio)->bi_rw & (1 << BIO_RW_META)) |
| #define bio_discard(bio) ((bio)->bi_rw & (1 << BIO_RW_DISCARD)) |
| #define bio_empty_barrier(bio) (bio_barrier(bio) && !bio_has_data(bio) && !bio_discard(bio)) |
| |
| static inline unsigned int bio_cur_sectors(struct bio *bio) |
| { |
| if (bio->bi_vcnt) |
| return bio_iovec(bio)->bv_len >> 9; |
| else /* dataless requests such as discard */ |
| return bio->bi_size >> 9; |
| } |
| |
| static inline void *bio_data(struct bio *bio) |
| { |
| if (bio->bi_vcnt) |
| 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, idx, kmtype) \ |
| (kmap_atomic(bio_iovec_idx((bio), (idx))->bv_page, kmtype) + \ |
| bio_iovec_idx((bio), (idx))->bv_offset) |
| |
| #define __bio_kunmap_atomic(addr, kmtype) kunmap_atomic(addr, kmtype) |
| |
| /* |
| * merge helpers etc |
| */ |
| |
| #define __BVEC_END(bio) bio_iovec_idx((bio), (bio)->bi_vcnt - 1) |
| #define __BVEC_START(bio) bio_iovec_idx((bio), (bio)->bi_idx) |
| |
| /* 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, (q)->seg_boundary_mask) |
| #define BIO_SEG_BOUNDARY(q, b1, b2) \ |
| BIOVEC_SEG_BOUNDARY((q), __BVEC_END((b1)), __BVEC_START((b2))) |
| |
| #define bio_io_error(bio) bio_endio((bio), -EIO) |
| |
| /* |
| * drivers should not use the __ version unless they _really_ want to |
| * run through the entire bio and not just pending pieces |
| */ |
| #define __bio_for_each_segment(bvl, bio, i, start_idx) \ |
| for (bvl = bio_iovec_idx((bio), (start_idx)), i = (start_idx); \ |
| i < (bio)->bi_vcnt; \ |
| bvl++, i++) |
| |
| #define bio_for_each_segment(bvl, bio, i) \ |
| __bio_for_each_segment(bvl, bio, i, (bio)->bi_idx) |
| |
| /* |
| * 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 |
| */ |
| #define bio_get(bio) atomic_inc(&(bio)->bi_cnt) |
| |
| #if defined(CONFIG_BLK_DEV_INTEGRITY) |
| /* |
| * bio integrity payload |
| */ |
| struct bio_integrity_payload { |
| struct bio *bip_bio; /* parent bio */ |
| struct bio_vec *bip_vec; /* integrity data vector */ |
| |
| sector_t bip_sector; /* virtual start sector */ |
| |
| void *bip_buf; /* generated integrity data */ |
| bio_end_io_t *bip_end_io; /* saved I/O completion fn */ |
| |
| int bip_error; /* saved I/O error */ |
| unsigned int bip_size; |
| |
| unsigned short bip_pool; /* pool the ivec came from */ |
| unsigned short bip_vcnt; /* # of integrity bio_vecs */ |
| unsigned short bip_idx; /* current bip_vec index */ |
| |
| struct work_struct bip_work; /* I/O completion */ |
| }; |
| #endif /* CONFIG_BLK_DEV_INTEGRITY */ |
| |
| /* |
| * A bio_pair is used when we need to split a bio. |
| * This can only happen for a bio that refers to just one |
| * page of data, and in the unusual situation when the |
| * page crosses a chunk/device boundary |
| * |
| * The address of the master bio is stored in bio1.bi_private |
| * The address of the pool the pair was allocated from is stored |
| * in bio2.bi_private |
| */ |
| struct bio_pair { |
| struct bio bio1, bio2; |
| struct bio_vec bv1, bv2; |
| #if defined(CONFIG_BLK_DEV_INTEGRITY) |
| struct bio_integrity_payload bip1, bip2; |
| struct bio_vec iv1, iv2; |
| #endif |
| atomic_t cnt; |
| int error; |
| }; |
| extern struct bio_pair *bio_split(struct bio *bi, int first_sectors); |
| extern void bio_pair_release(struct bio_pair *dbio); |
| |
| extern struct bio_set *bioset_create(int, int); |
| extern void bioset_free(struct bio_set *); |
| |
| extern struct bio *bio_alloc(gfp_t, int); |
| extern struct bio *bio_kmalloc(gfp_t, int); |
| extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *); |
| extern void bio_put(struct bio *); |
| extern void bio_free(struct bio *, struct bio_set *); |
| |
| extern void bio_endio(struct bio *, int); |
| struct request_queue; |
| extern int bio_phys_segments(struct request_queue *, struct bio *); |
| |
| extern void __bio_clone(struct bio *, struct bio *); |
| extern struct bio *bio_clone(struct bio *, gfp_t); |
| |
| extern void bio_init(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); |
| extern int bio_get_nr_vecs(struct block_device *); |
| extern sector_t bio_sector_offset(struct bio *, unsigned short, unsigned int); |
| extern struct bio *bio_map_user(struct request_queue *, struct block_device *, |
| unsigned long, unsigned int, int, gfp_t); |
| struct sg_iovec; |
| struct rq_map_data; |
| extern struct bio *bio_map_user_iov(struct request_queue *, |
| struct block_device *, |
| struct sg_iovec *, int, int, 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); |
| extern struct bio *bio_copy_user(struct request_queue *, struct rq_map_data *, |
| unsigned long, unsigned int, int, gfp_t); |
| extern struct bio *bio_copy_user_iov(struct request_queue *, |
| struct rq_map_data *, struct sg_iovec *, |
| int, int, gfp_t); |
| extern int bio_uncopy_user(struct bio *); |
| void zero_fill_bio(struct bio *bio); |
| extern struct bio_vec *bvec_alloc_bs(gfp_t, int, unsigned long *, struct bio_set *); |
| extern unsigned int bvec_nr_vecs(unsigned short idx); |
| |
| /* |
| * Allow queuer to specify a completion CPU for this bio |
| */ |
| static inline void bio_set_completion_cpu(struct bio *bio, unsigned int cpu) |
| { |
| bio->bi_comp_cpu = cpu; |
| } |
| |
| /* |
| * 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 { |
| mempool_t *bio_pool; |
| #if defined(CONFIG_BLK_DEV_INTEGRITY) |
| mempool_t *bio_integrity_pool; |
| #endif |
| mempool_t *bvec_pool; |
| }; |
| |
| struct biovec_slab { |
| int nr_vecs; |
| char *name; |
| struct kmem_cache *slab; |
| }; |
| |
| extern struct bio_set *fs_bio_set; |
| |
| /* |
| * a small number of entries is fine, not going to be performance critical. |
| * basically we just need to survive |
| */ |
| #define BIO_SPLIT_ENTRIES 2 |
| |
| #ifdef CONFIG_HIGHMEM |
| /* |
| * remember to add offset! and never ever reenable interrupts between a |
| * bvec_kmap_irq and bvec_kunmap_irq!! |
| * |
| * This function MUST be inlined - it plays with the CPU interrupt flags. |
| */ |
| 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, KM_BIO_SRC_IRQ); |
| |
| 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, KM_BIO_SRC_IRQ); |
| local_irq_restore(*flags); |
| } |
| |
| #else |
| #define bvec_kmap_irq(bvec, flags) (page_address((bvec)->bv_page) + (bvec)->bv_offset) |
| #define bvec_kunmap_irq(buf, flags) do { *(flags) = 0; } while (0) |
| #endif |
| |
| static inline char *__bio_kmap_irq(struct bio *bio, unsigned short idx, |
| unsigned long *flags) |
| { |
| return bvec_kmap_irq(bio_iovec_idx(bio, idx), flags); |
| } |
| #define __bio_kunmap_irq(buf, flags) bvec_kunmap_irq(buf, flags) |
| |
| #define bio_kmap_irq(bio, flags) \ |
| __bio_kmap_irq((bio), (bio)->bi_idx, (flags)) |
| #define bio_kunmap_irq(buf,flags) __bio_kunmap_irq(buf, flags) |
| |
| /* |
| * Check whether this bio carries any data or not. A NULL bio is allowed. |
| */ |
| static inline int bio_has_data(struct bio *bio) |
| { |
| return bio && bio->bi_io_vec != NULL; |
| } |
| |
| #if defined(CONFIG_BLK_DEV_INTEGRITY) |
| |
| #define bip_vec_idx(bip, idx) (&(bip->bip_vec[(idx)])) |
| #define bip_vec(bip) bip_vec_idx(bip, 0) |
| |
| #define __bip_for_each_vec(bvl, bip, i, start_idx) \ |
| for (bvl = bip_vec_idx((bip), (start_idx)), i = (start_idx); \ |
| i < (bip)->bip_vcnt; \ |
| bvl++, i++) |
| |
| #define bip_for_each_vec(bvl, bip, i) \ |
| __bip_for_each_vec(bvl, bip, i, (bip)->bip_idx) |
| |
| #define bio_integrity(bio) (bio->bi_integrity != NULL) |
| |
| extern struct bio_integrity_payload *bio_integrity_alloc_bioset(struct bio *, gfp_t, unsigned int, struct bio_set *); |
| extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int); |
| extern void bio_integrity_free(struct bio *, struct bio_set *); |
| extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int); |
| extern int bio_integrity_enabled(struct bio *bio); |
| extern int bio_integrity_set_tag(struct bio *, void *, unsigned int); |
| extern int bio_integrity_get_tag(struct bio *, void *, unsigned int); |
| extern int bio_integrity_prep(struct bio *); |
| extern void bio_integrity_endio(struct bio *, int); |
| extern void bio_integrity_advance(struct bio *, unsigned int); |
| extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int); |
| extern void bio_integrity_split(struct bio *, struct bio_pair *, int); |
| extern int bio_integrity_clone(struct bio *, struct bio *, struct bio_set *); |
| extern int bioset_integrity_create(struct bio_set *, int); |
| extern void bioset_integrity_free(struct bio_set *); |
| extern void bio_integrity_init_slab(void); |
| |
| #else /* CONFIG_BLK_DEV_INTEGRITY */ |
| |
| #define bio_integrity(a) (0) |
| #define bioset_integrity_create(a, b) (0) |
| #define bio_integrity_prep(a) (0) |
| #define bio_integrity_enabled(a) (0) |
| #define bio_integrity_clone(a, b, c) (0) |
| #define bioset_integrity_free(a) do { } while (0) |
| #define bio_integrity_free(a, b) do { } while (0) |
| #define bio_integrity_endio(a, b) do { } while (0) |
| #define bio_integrity_advance(a, b) do { } while (0) |
| #define bio_integrity_trim(a, b, c) do { } while (0) |
| #define bio_integrity_split(a, b, c) do { } while (0) |
| #define bio_integrity_set_tag(a, b, c) do { } while (0) |
| #define bio_integrity_get_tag(a, b, c) do { } while (0) |
| #define bio_integrity_init_slab(a) do { } while (0) |
| |
| #endif /* CONFIG_BLK_DEV_INTEGRITY */ |
| |
| #endif /* CONFIG_BLOCK */ |
| #endif /* __LINUX_BIO_H */ |