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

/* * include/linux/buffer_head.h * * Everything to do with buffer_heads. */ #ifndef _LINUX_BUFFER_HEAD_H #define _LINUX_BUFFER_HEAD_H #include <linux/types.h> #include <linux/fs.h> #include <linux/linkage.h> #include <linux/pagemap.h> #include <linux/wait.h> #include <asm/atomic.h> enum bh_state_bits { BH_Uptodate, /* Contains valid data */ BH_Dirty, /* Is dirty */ BH_Lock, /* Is locked */ BH_Req, /* Has been submitted for I/O */ BH_Uptodate_Lock,/* Used by the first bh in a page, to serialise * IO completion of other buffers in the page */ BH_Mapped, /* Has a disk mapping */ BH_New, /* Disk mapping was newly created by get_block */ BH_Async_Read, /* Is under end_buffer_async_read I/O */ BH_Async_Write, /* Is under end_buffer_async_write I/O */ BH_Delay, /* Buffer is not yet allocated on disk */ BH_Boundary, /* Block is followed by a discontiguity */ BH_Write_EIO, /* I/O error on write */ BH_Ordered, /* ordered write */ BH_Eopnotsupp, /* operation not supported (barrier) */ BH_PrivateStart,/* not a state bit, but the first bit available * for private allocation by other entities */ }; #define MAX_BUF_PER_PAGE (PAGE_CACHE_SIZE / 512) struct page; struct buffer_head; struct address_space; typedef void (bh_end_io_t)(struct buffer_head *bh, int uptodate); /* * Keep related fields in common cachelines. The most commonly accessed * field (b_state) goes at the start so the compiler does not generate * indexed addressing for it. */ struct buffer_head { /* First cache line: */ unsigned long b_state; /* buffer state bitmap (see above) */ struct buffer_head *b_this_page;/* circular list of page's buffers */ struct page *b_page; /* the page this bh is mapped to */ atomic_t b_count; /* users using this block */ u32 b_size; /* block size */ sector_t b_blocknr; /* block number */ char *b_data; /* pointer to data block */ struct block_device *b_bdev; bh_end_io_t *b_end_io; /* I/O completion */ void *b_private; /* reserved for b_end_io */ struct list_head b_assoc_buffers; /* associated with another mapping */ }; /* * macro tricks to expand the set_buffer_foo(), clear_buffer_foo() * and buffer_foo() functions. */ #define BUFFER_FNS(bit, name) \ static inline void set_buffer_##name(struct buffer_head *bh) \ { \ set_bit(BH_##bit, &(bh)->b_state); \ } \ static inline void clear_buffer_##name(struct buffer_head *bh) \ { \ clear_bit(BH_##bit, &(bh)->b_state); \ } \ static inline int buffer_##name(const struct buffer_head *bh) \ { \ return test_bit(BH_##bit, &(bh)->b_state); \ } /* * test_set_buffer_foo() and test_clear_buffer_foo() */ #define TAS_BUFFER_FNS(bit, name) \ static inline int test_set_buffer_##name(struct buffer_head *bh) \ { \ return test_and_set_bit(BH_##bit, &(bh)->b_state); \ } \ static inline int test_clear_buffer_##name(struct buffer_head *bh) \ { \ return test_and_clear_bit(BH_##bit, &(bh)->b_state); \ } \ /* * Emit the buffer bitops functions. Note that there are also functions * of the form "mark_buffer_foo()". These are higher-level functions which * do something in addition to setting a b_state bit. */ BUFFER_FNS(Uptodate, uptodate) BUFFER_FNS(Dirty, dirty) TAS_BUFFER_FNS(Dirty, dirty) BUFFER_FNS(Lock, locked) TAS_BUFFER_FNS(Lock, locked) BUFFER_FNS(Req, req) TAS_BUFFER_FNS(Req, req) BUFFER_FNS(Mapped, mapped) BUFFER_FNS(New, new) BUFFER_FNS(Async_Read, async_read) BUFFER_FNS(Async_Write, async_write) BUFFER_FNS(Delay, delay) BUFFER_FNS(Boundary, boundary) BUFFER_FNS(Write_EIO, write_io_error) BUFFER_FNS(Ordered, ordered) BUFFER_FNS(Eopnotsupp, eopnotsupp) #define bh_offset(bh) ((unsigned long)(bh)->b_data & ~PAGE_MASK) #define touch_buffer(bh) mark_page_accessed(bh->b_page) /* If we *know* page->private refers to buffer_heads */ #define page_buffers(page) \ ({ \ BUG_ON(!PagePrivate(page)); \ ((struct buffer_head *)page_private(page)); \ }) #define page_has_buffers(page) PagePrivate(page) /* * Declarations */ void FASTCALL(mark_buffer_dirty(struct buffer_head *bh)); void init_buffer(struct buffer_head *, bh_end_io_t *, void *); void set_bh_page(struct buffer_head *bh, struct page *page, unsigned long offset); int try_to_free_buffers(struct page *); struct buffer_head *alloc_page_buffers(struct page *page, unsigned long size, int retry); void create_empty_buffers(struct page *, unsigned long, unsigned long b_state); void end_buffer_read_sync(struct buffer_head *bh, int uptodate); void end_buffer_write_sync(struct buffer_head *bh, int uptodate); void end_buffer_async_write(struct buffer_head *bh, int uptodate); /* Things to do with buffers at mapping->private_list */ void mark_buffer_dirty_inode(struct buffer_head *bh, struct inode *inode); int inode_has_buffers(struct inode *); void invalidate_inode_buffers(struct inode *); int remove_inode_buffers(struct inode *inode); int sync_mapping_buffers(struct address_space *mapping); void unmap_underlying_metadata(struct block_device *bdev, sector_t block); void mark_buffer_async_write(struct buffer_head *bh); void invalidate_bdev(struct block_device *, int); int sync_blockdev(struct block_device *bdev); void __wait_on_buffer(struct buffer_head *); wait_queue_head_t *bh_waitq_head(struct buffer_head *bh); int fsync_bdev(struct block_device *); struct super_block *freeze_bdev(struct block_device *); void thaw_bdev(struct block_device *, struct super_block *); int fsync_super(struct super_block *); int fsync_no_super(struct block_device *); struct buffer_head *__find_get_block(struct block_device *, sector_t, int); struct buffer_head * __getblk(struct block_device *, sector_t, int); void __brelse(struct buffer_head *); void __bforget(struct buffer_head *); void __breadahead(struct block_device *, sector_t block, int size); struct buffer_head *__bread(struct block_device *, sector_t block, int size); struct buffer_head *alloc_buffer_head(gfp_t gfp_flags); void free_buffer_head(struct buffer_head * bh); void FASTCALL(unlock_buffer(struct buffer_head *bh)); void FASTCALL(__lock_buffer(struct buffer_head *bh)); void ll_rw_block(int, int, struct buffer_head * bh[]); int sync_dirty_buffer(struct buffer_head *bh); int submit_bh(int, struct buffer_head *); void write_boundary_block(struct block_device *bdev, sector_t bblock, unsigned blocksize); extern int buffer_heads_over_limit; /* * Generic address_space_operations implementations for buffer_head-backed * address_spaces. */ int try_to_release_page(struct page * page, gfp_t gfp_mask); int block_invalidatepage(struct page *page, unsigned long offset); int do_invalidatepage(struct page *page, unsigned long offset); int block_write_full_page(struct page *page, get_block_t *get_block, struct writeback_control *wbc); int block_read_full_page(struct page*, get_block_t*); int block_prepare_write(struct page*, unsigned, unsigned, get_block_t*); int cont_prepare_write(struct page*, unsigned, unsigned, get_block_t*, loff_t *); int generic_cont_expand(struct inode *inode, loff_t size); int generic_cont_expand_simple(struct inode *inode, loff_t size); int block_commit_write(struct page *page, unsigned from, unsigned to); int block_sync_page(struct page *); sector_t generic_block_bmap(struct address_space *, sector_t, get_block_t *); int generic_commit_write(struct file *, struct page *, unsigned, unsigned); int block_truncate_page(struct address_space *, loff_t, get_block_t *); int file_fsync(struct file *, struct dentry *, int); int nobh_prepare_write(struct page*, unsigned, unsigned, get_block_t*); int nobh_commit_write(struct file *, struct page *, unsigned, unsigned); int nobh_truncate_page(struct address_space *, loff_t); int nobh_writepage(struct page *page, get_block_t *get_block, struct writeback_control *wbc); /* * inline definitions */ static inline void attach_page_buffers(struct page *page, struct buffer_head *head) { page_cache_get(page); SetPagePrivate(page); set_page_private(page, (unsigned long)head); } static inline void get_bh(struct buffer_head *bh) { atomic_inc(&bh->b_count); } static inline void put_bh(struct buffer_head *bh) { smp_mb__before_atomic_dec(); atomic_dec(&bh->b_count); } static inline void brelse(struct buffer_head *bh) { if (bh) __brelse(bh); } static inline void bforget(struct buffer_head *bh) { if (bh) __bforget(bh); } static inline struct buffer_head * sb_bread(struct super_block *sb, sector_t block) { return __bread(sb->s_bdev, block, sb->s_blocksize); } static inline void sb_breadahead(struct super_block *sb, sector_t block) { __breadahead(sb->s_bdev, block, sb->s_blocksize); } static inline struct buffer_head * sb_getblk(struct super_block *sb, sector_t block) { return __getblk(sb->s_bdev, block, sb->s_blocksize); } static inline struct buffer_head * sb_find_get_block(struct super_block *sb, sector_t block) { return __find_get_block(sb->s_bdev, block, sb->s_blocksize); } static inline void map_bh(struct buffer_head *bh, struct super_block *sb, sector_t block) { set_buffer_mapped(bh); bh->b_bdev = sb->s_bdev; bh->b_blocknr = block; } /* * Calling wait_on_buffer() for a zero-ref buffer is illegal, so we call into * __wait_on_buffer() just to trip a debug check. Because debug code in inline * functions is bloaty. */ static inline void wait_on_buffer(struct buffer_head *bh) { might_sleep(); if (buffer_locked(bh) || atomic_read(&bh->b_count) == 0) __wait_on_buffer(bh); } static inline void lock_buffer(struct buffer_head *bh) { might_sleep(); if (test_set_buffer_locked(bh)) __lock_buffer(bh); } #endif /* _LINUX_BUFFER_HEAD_H */