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 ram_bytes;
  30         u64 block_start;
  31         u64 block_len;
  32         u64 generation;
  33         unsigned long flags;
  34         struct block_device *bdev;
  35         atomic_t refs;
  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 int extent_map_in_tree(const struct extent_map *em)
  47 {
  48         return !RB_EMPTY_NODE(&em->rb_node);
  49 }
  50
  51 static inline u64 extent_map_end(struct extent_map *em)
  52 {
  53         if (em->start + em->len < em->start)
  54                 return (u64)-1;
  55         return em->start + em->len;
  56 }
  57
  58 static inline u64 extent_map_block_end(struct extent_map *em)
  59 {
  60         if (em->block_start + em->block_len < em->block_start)
  61                 return (u64)-1;
  62         return em->block_start + em->block_len;
  63 }
  64
  65 void extent_map_tree_init(struct extent_map_tree *tree);
  66 struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
  67                                          u64 start, u64 len);
  68 int add_extent_mapping(struct extent_map_tree *tree,
  69                        struct extent_map *em, int modified);
  70 int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
  71 void replace_extent_mapping(struct extent_map_tree *tree,
  72                             struct extent_map *cur,
  73                             struct extent_map *new,
  74                             int modified);
  75
  76 struct extent_map *alloc_extent_map(void);
  77 void free_extent_map(struct extent_map *em);
  78 int __init extent_map_init(void);
  79 void extent_map_exit(void);
  80 int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len, u64 gen);
  81 void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em);
  82 struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
  83                                          u64 start, u64 len);
  84 #endif