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 in_tree;
  37         unsigned int compress_type;
  38         struct list_head list;
  39 };
  40
  41 struct extent_map_tree {
  42         struct rb_root map;
  43         struct list_head modified_extents;
  44         rwlock_t lock;
  45 };
  46
  47 static inline u64 extent_map_end(struct extent_map *em)
  48 {
  49         if (em->start + em->len < em->start)
  50                 return (u64)-1;
  51         return em->start + em->len;
  52 }
  53
  54 static inline u64 extent_map_block_end(struct extent_map *em)
  55 {
  56         if (em->block_start + em->block_len < em->block_start)
  57                 return (u64)-1;
  58         return em->block_start + em->block_len;
  59 }
  60
  61 void extent_map_tree_init(struct extent_map_tree *tree);
  62 struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
  63                                          u64 start, u64 len);
  64 int add_extent_mapping(struct extent_map_tree *tree,
  65                        struct extent_map *em, int modified);
  66 int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
  67
  68 struct extent_map *alloc_extent_map(void);
  69 void free_extent_map(struct extent_map *em);
  70 int __init extent_map_init(void);
  71 void extent_map_exit(void);
  72 int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len, u64 gen);
  73 void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em);
  74 struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
  75                                          u64 start, u64 len);
  76 #endif