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 /* bits for the flags field */
  12 #define EXTENT_FLAG_PINNED 0 /* this entry not yet on disk, don't free it */
  13
  14 struct extent_map {
  15         struct rb_node rb_node;
  16
  17         /* all of these are in bytes */
  18         u64 start;
  19         u64 len;
  20         u64 block_start;
  21         unsigned long flags;
  22         struct block_device *bdev;
  23         atomic_t refs;
  24         int in_tree;
  25 };
  26
  27 struct extent_map_tree {
  28         struct rb_root map;
  29         spinlock_t lock;
  30 };
  31
  32 static inline u64 extent_map_end(struct extent_map *em)
  33 {
  34         if (em->start + em->len < em->start)
  35                 return (u64)-1;
  36         return em->start + em->len;
  37 }
  38
  39 static inline u64 extent_map_block_end(struct extent_map *em)
  40 {
  41         if (em->block_start + em->len < em->block_start)
  42                 return (u64)-1;
  43         return em->block_start + em->len;
  44 }
  45
  46 void extent_map_tree_init(struct extent_map_tree *tree, gfp_t mask);
  47 struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
  48                                          u64 start, u64 len);
  49 int add_extent_mapping(struct extent_map_tree *tree,
  50                        struct extent_map *em);
  51 int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
  52
  53 struct extent_map *alloc_extent_map(gfp_t mask);
  54 void free_extent_map(struct extent_map *em);
  55 int __init extent_map_init(void);
  56 void extent_map_exit(void);
  57 #endif