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 #define EXTENT_FLAG_FILLING 5 /* Filling in a preallocated extent */
  18
  19 struct extent_map {
  20         struct rb_node rb_node;
  21
  22         /* all of these are in bytes */
  23         u64 start;
  24         u64 len;
  25         u64 mod_start;
  26         u64 mod_len;
  27         u64 orig_start;
  28         u64 orig_block_len;
  29         u64 block_start;
  30         u64 block_len;
  31         u64 generation;
  32         unsigned long flags;
  33         struct block_device *bdev;
  34         atomic_t refs;
  35         unsigned int in_tree;
  36         unsigned int compress_type;
  37         struct list_head list;
  38 };
  39
  40 struct extent_map_tree {
  41         struct rb_root map;
  42         struct list_head modified_extents;
  43         rwlock_t lock;
  44 };
  45
  46 static inline u64 extent_map_end(struct extent_map *em)
  47 {
  48         if (em->start + em->len < em->start)
  49                 return (u64)-1;
  50         return em->start + em->len;
  51 }
  52
  53 static inline u64 extent_map_block_end(struct extent_map *em)
  54 {
  55         if (em->block_start + em->block_len < em->block_start)
  56                 return (u64)-1;
  57         return em->block_start + em->block_len;
  58 }
  59
  60 void extent_map_tree_init(struct extent_map_tree *tree);
  61 struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
  62                                          u64 start, u64 len);
  63 int add_extent_mapping(struct extent_map_tree *tree,
  64                        struct extent_map *em);
  65 int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
  66
  67 struct extent_map *alloc_extent_map(void);
  68 void free_extent_map(struct extent_map *em);
  69 int __init extent_map_init(void);
  70 void extent_map_exit(void);
  71 int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len, u64 gen);
  72 void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em);
  73 struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
  74                                          u64 start, u64 len);
  75 #endif