http://www.ousob.com --- Legacy Redefined OuSob - File: /wwwroot/clipx/usr/include/linux/bio.h

/* * 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> /* Platforms may set this to teach the BIO layer about IOMMU hardware. */ #include <asm/io.h> #if defined(BIO_VMERGE_MAX_SIZE) && defined(BIO_VMERGE_BOUNDARY) #define BIOVEC_VIRT_START_SIZE(x) (bvec_to_phys(x) & (BIO_VMERGE_BOUNDARY - 1)) #define BIOVEC_VIRT_OVERSIZE(x) ((x) > BIO_VMERGE_MAX_SIZE) #else #define BIOVEC_VIRT_START_SIZE(x) 0 #define BIOVEC_VIRT_OVERSIZE(x) 0 #endif #ifndef BIO_VMERGE_BOUNDARY #define BIO_VMERGE_BOUNDARY 0 #endif #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; typedef int (bio_end_io_t) (struct bio *, unsigned int, 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; 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 short bi_phys_segments; /* Number of segments after physical and DMA remapping * hardware coalescing is performed. */ unsigned short bi_hw_segments; unsigned int bi_size; /* residual I/O count */ /* * To keep track of the max hw size, we account for the * sizes of the first and last virtually mergeable segments * in this bio */ unsigned int bi_hw_front_size; unsigned int bi_hw_back_size; unsigned int bi_max_vecs; /* max bvl_vecs we can hold */ struct bio_vec *bi_io_vec; /* the actual vec list */ bio_end_io_t *bi_end_io; atomic_t bi_cnt; /* pin count */ void *bi_private; 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 /* nr_hw_seg 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_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 -- read (not set) or write (set) * bit 1 -- rw-ahead when set * bit 2 -- barrier * bit 3 -- fail fast, don't want low level driver retries * bit 4 -- synchronous I/O hint: the block layer will unplug immediately */ #define BIO_RW 0 #define BIO_RW_AHEAD 1 #define BIO_RW_BARRIER 2 #define BIO_RW_FAILFAST 3 #define BIO_RW_SYNC 4 /* * 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_cur_sectors(bio) (bio_iovec(bio)->bv_len >> 9) #define bio_data(bio) (page_address(bio_page((bio))) + bio_offset((bio))) #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(bio) ((bio)->bi_rw & (1 << BIO_RW_FAILFAST)) #define bio_rw_ahead(bio) ((bio)->bi_rw & (1 << BIO_RW_AHEAD)) /* * 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) /* * allow arch override, for eg virtualized architectures (put in asm/io.h) */ #ifndef BIOVEC_PHYS_MERGEABLE #define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \ ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2))) #endif #define BIOVEC_VIRT_MERGEABLE(vec1, vec2) \ ((((bvec_to_phys((vec1)) + (vec1)->bv_len) | bvec_to_phys((vec2))) & (BIO_VMERGE_BOUNDARY - 1)) == 0) #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, bytes) bio_endio((bio), (bytes), -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) /* * 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; atomic_t cnt; int error; }; extern struct bio_pair *bio_split(struct bio *bi, mempool_t *pool, int first_sectors); extern mempool_t *bio_split_pool; extern void bio_pair_release(struct bio_pair *dbio); extern struct bio_set *bioset_create(int, int, int); extern void bioset_free(struct bio_set *); extern struct bio *bio_alloc(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 *, unsigned int, int); struct request_queue; extern int bio_phys_segments(struct request_queue *, struct bio *); extern int bio_hw_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 struct bio *bio_map_user(struct request_queue *, struct block_device *, unsigned long, unsigned int, int); struct sg_iovec; extern struct bio *bio_map_user_iov(struct request_queue *, struct block_device *, struct sg_iovec *, int, int); extern void bio_unmap_user(struct bio *); extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int, gfp_t); 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 *, unsigned long, unsigned int, int); extern int bio_uncopy_user(struct bio *); void zero_fill_bio(struct bio *bio); #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) #endif /* __LINUX_BIO_H */