#include <linux/types.h>
#include <linux/fs.h>
#include <linux/linkage.h>
+#include <linux/pagemap.h>
#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_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_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
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) */
- atomic_t b_count; /* users using this block */
struct buffer_head *b_this_page;/* circular list of page's buffers */
struct page *b_page; /* the page this bh is mapped to */
- sector_t b_blocknr; /* block number */
- u32 b_size; /* block size */
- 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 */
};
/*
{ \
clear_bit(BH_##bit, &(bh)->b_state); \
} \
-static inline int buffer_##name(struct buffer_head *bh) \
+static inline int buffer_##name(const struct buffer_head *bh) \
{ \
return test_bit(BH_##bit, &(bh)->b_state); \
}
BUFFER_FNS(Async_Write, async_write)
BUFFER_FNS(Delay, delay)
BUFFER_FNS(Boundary, boundary)
-BUFFER_FNS(Write_EIO,write_io_error)
+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); \
+ BUG_ON(!PagePrivate(page)); \
+ ((struct buffer_head *)page_private(page)); \
})
#define page_has_buffers(page) PagePrivate(page)
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 buffer_insert_list(spinlock_t *lock,
- struct buffer_head *, struct list_head *);
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 fsync_buffers_list(spinlock_t *lock, struct list_head *);
int sync_mapping_buffers(struct address_space *mapping);
void unmap_underlying_metadata(struct block_device *bdev, sector_t block);
-void mark_buffer_async_read(struct buffer_head *bh);
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);
-void wake_up_buffer(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 *);
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(int gfp_flags);
+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[]);
-void sync_dirty_buffer(struct buffer_head *bh);
-void submit_bh(int, struct buffer_head *);
+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);
* 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_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(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 *);
+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 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);
-#define OSYNC_METADATA (1<<0)
-#define OSYNC_DATA (1<<1)
-#define OSYNC_INODE (1<<2)
-int generic_osync_inode(struct inode *, struct address_space *, int);
-
+void buffer_init(void);
/*
* 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);
set_buffer_mapped(bh);
bh->b_bdev = sb->s_bdev;
bh->b_blocknr = block;
+ bh->b_size = sb->s_blocksize;
}
/*
*/
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);
}
+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, int destroy_dirty_buffers) {}
+
+
+#endif /* CONFIG_BLOCK */
#endif /* _LINUX_BUFFER_HEAD_H */