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 #define EXTENT_FLAG_LOGGING 4 /* Logging this extent */
  17
  18 struct extent_map {
  19         struct rb_node rb_node;
  20
  21         /* all of these are in bytes */
  22         u64 start;
  23         u64 len;
  24         u64 mod_start;
  25         u64 mod_len;
  26         u64 orig_start;
  27         u64 block_start;
  28         u64 block_len;
  29         u64 generation;
  30         unsigned long flags;
  31         struct block_device *bdev;
  32         atomic_t refs;
  33         unsigned int in_tree;
  34         unsigned int compress_type;
  35         struct list_head list;
  36 };
  37
  38 struct extent_map_tree {
  39         struct rb_root map;
  40         struct list_head modified_extents;
  41         rwlock_t lock;
  42 };
  43
  44 static inline u64 extent_map_end(struct extent_map *em)
  45 {
  46         if (em->start + em->len < em->start)
  47                 return (u64)-1;
  48         return em->start + em->len;
  49 }
  50
  51 static inline u64 extent_map_block_end(struct extent_map *em)
  52 {
  53         if (em->block_start + em->block_len < em->block_start)
  54                 return (u64)-1;
  55         return em->block_start + em->block_len;
  56 }
  57
  58 void extent_map_tree_init(struct extent_map_tree *tree);
  59 struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
  60                                          u64 start, u64 len);
  61 int add_extent_mapping(struct extent_map_tree *tree,
  62                        struct extent_map *em);
  63 int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
  64
  65 struct extent_map *alloc_extent_map(void);
  66 void free_extent_map(struct extent_map *em);
  67 int __init extent_map_init(void);
  68 void extent_map_exit(void);
  69 int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len, u64 gen);
  70 struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
  71                                          u64 start, u64 len);
  72 #endif