#include <linux/wait.h>
#include <asm/atomic.h>
+#ifdef CONFIG_BLOCK
+
enum bh_state_bits {
BH_Uptodate, /* Contains valid data */
BH_Dirty, /* Is dirty */
BH_Write_EIO, /* I/O error on write */
BH_Ordered, /* ordered write */
BH_Eopnotsupp, /* operation not supported (barrier) */
+ BH_Unwritten, /* Buffer is allocated on disk but not written */
BH_PrivateStart,/* not a state bit, but the first bit available
* for private allocation by other entities
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.
+ * Historically, a buffer_head was used to map a single block
+ * within a page, and of course as the unit of I/O through the
+ * filesystem and block layers. Nowadays the basic I/O unit
+ * is the bio, and buffer_heads are used for extracting block
+ * mappings (via a get_block_t call), for tracking state within
+ * a page (via a page_mapping) and for wrapping bio submission
+ * for backward compatibility reasons (e.g. submit_bh).
*/
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 */
+ sector_t b_blocknr; /* start block number */
+ size_t b_size; /* size of mapping */
+ char *b_data; /* pointer to data within the page */
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 */
+ struct address_space *b_assoc_map; /* mapping this buffer is
+ associated with */
+ atomic_t b_count; /* users using this buffer_head */
};
/*
BUFFER_FNS(Write_EIO, write_io_error)
BUFFER_FNS(Ordered, ordered)
BUFFER_FNS(Eopnotsupp, eopnotsupp)
+BUFFER_FNS(Unwritten, unwritten)
#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); \
+ BUG_ON(!PagePrivate(page)); \
+ ((struct buffer_head *)page_private(page)); \
})
#define page_has_buffers(page) PagePrivate(page)
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);
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);
+void invalidate_bdev(struct block_device *);
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);
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);
+struct buffer_head *__find_get_block(struct block_device *bdev, sector_t block,
+ unsigned size);
+struct buffer_head *__getblk(struct block_device *bdev, sector_t block,
+ unsigned size);
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);
+void __breadahead(struct block_device *, sector_t block, unsigned int size);
+struct buffer_head *__bread(struct block_device *, sector_t block, unsigned size);
+void invalidate_bh_lrus(void);
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));
* Generic address_space_operations implementations for buffer_head-backed
* address_spaces.
*/
-int try_to_release_page(struct page * page, int gfp_mask);
-int block_invalidatepage(struct page *page, unsigned long offset);
+void block_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_write_begin(struct file *, struct address_space *,
+ loff_t, unsigned, unsigned,
+ struct page **, void **, get_block_t*);
+int block_write_end(struct file *, struct address_space *,
+ loff_t, unsigned, unsigned,
+ struct page *, void *);
+int generic_write_end(struct file *, struct address_space *,
+ loff_t, unsigned, unsigned,
+ struct page *, void *);
+void page_zero_new_buffers(struct page *page, unsigned from, unsigned to);
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 cont_write_begin(struct file *, struct address_space *, loff_t,
+ unsigned, unsigned, struct page **, void **,
+ get_block_t *, loff_t *);
+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 *);
+int block_page_mkwrite(struct vm_area_struct *vma, struct page *page,
+ get_block_t get_block);
+void 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_write_begin(struct file *, struct address_space *,
+ loff_t, unsigned, unsigned,
+ struct page **, void **, get_block_t*);
+int nobh_write_end(struct file *, struct address_space *,
+ loff_t, unsigned, unsigned,
+ struct page *, void *);
+int nobh_truncate_page(struct address_space *, loff_t, get_block_t *);
int nobh_writepage(struct page *page, get_block_t *get_block,
struct writeback_control *wbc);
+void buffer_init(void);
/*
* inline definitions
{
page_cache_get(page);
SetPagePrivate(page);
- page->private = (unsigned long)head;
+ set_page_private(page, (unsigned long)head);
}
static inline void get_bh(struct buffer_head *bh)
set_buffer_mapped(bh);
bh->b_bdev = sb->s_bdev;
bh->b_blocknr = block;
+ bh->b_size = sb->s_blocksize;
}
/*
__lock_buffer(bh);
}
+extern int __set_page_dirty_buffers(struct page *page);
+
+#else /* CONFIG_BLOCK */
+
+static inline void buffer_init(void) {}
+static inline int try_to_free_buffers(struct page *page) { return 1; }
+static inline int sync_blockdev(struct block_device *bdev) { return 0; }
+static inline int inode_has_buffers(struct inode *inode) { return 0; }
+static inline void invalidate_inode_buffers(struct inode *inode) {}
+static inline int remove_inode_buffers(struct inode *inode) { return 1; }
+static inline int sync_mapping_buffers(struct address_space *mapping) { return 0; }
+static inline void invalidate_bdev(struct block_device *bdev) {}
+
+
+#endif /* CONFIG_BLOCK */
#endif /* _LINUX_BUFFER_HEAD_H */
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff