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         unsigned int in_tree:1;
  30         unsigned int compress_type:4;
  31 };
  32
  33 struct extent_map_tree {
  34         struct rb_root map;
  35         rwlock_t lock;
  36 };
  37
  38 static inline u64 extent_map_end(struct extent_map *em)
  39 {
  40         if (em->start + em->len < em->start)
  41                 return (u64)-1;
  42         return em->start + em->len;
  43 }
  44
  45 static inline u64 extent_map_block_end(struct extent_map *em)
  46 {
  47         if (em->block_start + em->block_len < em->block_start)
  48                 return (u64)-1;
  49         return em->block_start + em->block_len;
  50 }
  51
  52 void extent_map_tree_init(struct extent_map_tree *tree, gfp_t mask);
  53 struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
  54                                          u64 start, u64 len);
  55 int add_extent_mapping(struct extent_map_tree *tree,
  56                        struct extent_map *em);
  57 int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
  58
  59 struct extent_map *alloc_extent_map(gfp_t mask);
  60 void free_extent_map(struct extent_map *em);
  61 int __init extent_map_init(void);
  62 void extent_map_exit(void);
  63 int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len);
  64 struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
  65                                          u64 start, u64 len);
  66 #endif