linux/fs/btrfs/extent_map.h
Christoph Hellwig d396c6f554 Btrfs: [PATCH] extent_map: provide generic bmap
generic_bmap is completely trivial, while the extent to bh mapping in
btrfs is rather complex.  So provide a extent_bmap instead that takes
a get_extent callback and can be used by filesystem using the extent_map
code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-09-10 20:02:30 -04:00

108 lines
3.6 KiB
C

#ifndef __EXTENTMAP__
#define __EXTENTMAP__
#include <linux/rbtree.h>
#define EXTENT_MAP_INLINE (u64)-2
#define EXTENT_MAP_DELALLOC (u64)-1
struct extent_map_ops {
int (*fill_delalloc)(struct inode *inode, u64 start, u64 end);
int (*writepage_io_hook)(struct page *page, u64 start, u64 end);
int (*readpage_io_hook)(struct page *page, u64 start, u64 end);
int (*readpage_end_io_hook)(struct page *page, u64 start, u64 end);
};
struct extent_map_tree {
struct rb_root map;
struct rb_root state;
struct address_space *mapping;
rwlock_t lock;
struct extent_map_ops *ops;
};
/* note, this must start with the same fields as fs/extent_map.c:tree_entry */
struct extent_map {
u64 start;
u64 end; /* inclusive */
int in_tree;
struct rb_node rb_node;
/* block_start and block_end are in bytes */
u64 block_start;
u64 block_end; /* inclusive */
struct block_device *bdev;
atomic_t refs;
};
/* note, this must start with the same fields as fs/extent_map.c:tree_entry */
struct extent_state {
u64 start;
u64 end; /* inclusive */
int in_tree;
struct rb_node rb_node;
wait_queue_head_t wq;
atomic_t refs;
unsigned long state;
/* for use by the FS */
u64 private;
struct list_head list;
};
struct extent_buffer {
u64 start;
u64 end; /* inclusive */
char *addr;
struct page *pages[];
};
typedef struct extent_map *(get_extent_t)(struct inode *inode,
struct page *page,
size_t page_offset,
u64 start, u64 end,
int create);
void extent_map_tree_init(struct extent_map_tree *tree,
struct address_space *mapping, gfp_t mask);
struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
u64 start, u64 end);
int add_extent_mapping(struct extent_map_tree *tree,
struct extent_map *em);
int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
int try_release_extent_mapping(struct extent_map_tree *tree, struct page *page);
int lock_extent(struct extent_map_tree *tree, u64 start, u64 end, gfp_t mask);
int unlock_extent(struct extent_map_tree *tree, u64 start, u64 end, gfp_t mask);
struct extent_map *alloc_extent_map(gfp_t mask);
void free_extent_map(struct extent_map *em);
int extent_read_full_page(struct extent_map_tree *tree, struct page *page,
get_extent_t *get_extent);
void __init extent_map_init(void);
void __exit extent_map_exit(void);
int extent_clean_all_trees(struct extent_map_tree *tree);
int set_extent_uptodate(struct extent_map_tree *tree, u64 start, u64 end,
gfp_t mask);
int set_extent_new(struct extent_map_tree *tree, u64 start, u64 end,
gfp_t mask);
int set_extent_dirty(struct extent_map_tree *tree, u64 start, u64 end,
gfp_t mask);
int set_extent_delalloc(struct extent_map_tree *tree, u64 start, u64 end,
gfp_t mask);
int extent_invalidatepage(struct extent_map_tree *tree,
struct page *page, unsigned long offset);
int extent_write_full_page(struct extent_map_tree *tree, struct page *page,
get_extent_t *get_extent,
struct writeback_control *wbc);
int extent_prepare_write(struct extent_map_tree *tree,
struct inode *inode, struct page *page,
unsigned from, unsigned to, get_extent_t *get_extent);
int extent_commit_write(struct extent_map_tree *tree,
struct inode *inode, struct page *page,
unsigned from, unsigned to);
sector_t extent_bmap(struct address_space *mapping, sector_t iblock,
get_extent_t *get_extent);
int set_range_dirty(struct extent_map_tree *tree, u64 start, u64 end);
int set_state_private(struct extent_map_tree *tree, u64 start, u64 private);
int get_state_private(struct extent_map_tree *tree, u64 start, u64 *private);
#endif