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 #define EXTENT_FLAG_COMPRESSED 1
  14 #define EXTENT_FLAG_VACANCY 2 /* no file extent item found */
  15 #define EXTENT_FLAG_PREALLOC 3 /* pre-allocated extent */
  16
  17 struct extent_map {
  18         struct rb_node rb_node;
  19
  20         /* all of these are in bytes */
  21         u64 start;
  22         u64 len;
  23         u64 orig_start;
  24         u64 block_start;
  25         u64 block_len;
  26         unsigned long flags;
  27         struct block_device *bdev;
  28         atomic_t refs;
  29         int in_tree;
  30 };
  31
  32 struct extent_map_tree {
  33         struct rb_root map;
  34         rwlock_t lock;
  35 };
  36
  37 static inline u64 extent_map_end(struct extent_map *em)
  38 {
  39         if (em->start + em->len < em->start)
  40                 return (u64)-1;
  41         return em->start + em->len;
  42 }
  43
  44 static inline u64 extent_map_block_end(struct extent_map *em)
  45 {
  46         if (em->block_start + em->block_len < em->block_start)
  47                 return (u64)-1;
  48         return em->block_start + em->block_len;
  49 }
  50
  51 void extent_map_tree_init(struct extent_map_tree *tree, gfp_t mask);
  52 struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
  53                                          u64 start, u64 len);
  54 int add_extent_mapping(struct extent_map_tree *tree,
  55                        struct extent_map *em);
  56 int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
  57
  58 struct extent_map *alloc_extent_map(gfp_t mask);
  59 void free_extent_map(struct extent_map *em);
  60 int __init extent_map_init(void);
  61 void extent_map_exit(void);
  62 int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len);
  63 struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
  64                                          u64 start, u64 len);
  65 #endif