fs/btrfs/extent_map.h

   1 #ifndef __EXTENTMAP__
   2 #define __EXTENTMAP__
   3
   4 #include <linux/rbtree.h>
   5
   6 #define EXTENT_MAP_LAST_BYTE (u64)-4
   7 #define EXTENT_MAP_HOLE (u64)-3
   8 #define EXTENT_MAP_INLINE (u64)-2
   9 #define EXTENT_MAP_DELALLOC (u64)-1
  10
  11 struct extent_map {
  12         struct rb_node rb_node;
  13
  14         /* all of these are in bytes */
  15         u64 start;
  16         u64 len;
  17         u64 block_start;
  18         unsigned long flags;
  19         struct block_device *bdev;
  20         atomic_t refs;
  21         int in_tree;
  22 };
  23
  24 struct extent_map_tree {
  25         struct rb_root map;
  26         struct extent_map *last;
  27         spinlock_t lock;
  28 };
  29
  30 static inline u64 extent_map_end(struct extent_map *em)
  31 {
  32         if (em->start + em->len < em->start)
  33                 return (u64)-1;
  34         return em->start + em->len;
  35 }
  36
  37 static inline u64 extent_map_block_end(struct extent_map *em)
  38 {
  39         if (em->block_start + em->len < em->block_start)
  40                 return (u64)-1;
  41         return em->block_start + em->len;
  42 }
  43
  44 void extent_map_tree_init(struct extent_map_tree *tree, gfp_t mask);
  45 struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
  46                                          u64 start, u64 len);
  47 int add_extent_mapping(struct extent_map_tree *tree,
  48                        struct extent_map *em);
  49 int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
  50
  51 struct extent_map *alloc_extent_map(gfp_t mask);
  52 void free_extent_map(struct extent_map *em);
  53 int __init extent_map_init(void);
  54 void extent_map_exit(void);
  55 #endif