LXR linux/fs/btrfs/extent

   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
  17struct 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        int in_tree;
  30};
  31
  32struct extent_map_tree {
  33        struct rb_root map;
  34        rwlock_t lock;
  35};
  36
  37static inline u64 extent_map_end(struct extent_map *em)
  38{
  39        if (em->start + em->len < em->start)
  40                return (u64)-1;
  41        return em->start + em->len;
  42}
  43
  44static inline u64 extent_map_block_end(struct extent_map *em)
  45{
  46        if (em->block_start + em->block_len < em->block_start)
  47                return (u64)-1;
  48        return em->block_start + em->block_len;
  49}
  50
  51void extent_map_tree_init(struct extent_map_tree *tree, gfp_t mask);
  52struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
  53                                         u64 start, u64 len);
  54int add_extent_mapping(struct extent_map_tree *tree,
  55                       struct extent_map *em);
  56int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
  57
  58struct extent_map *alloc_extent_map(gfp_t mask);
  59void free_extent_map(struct extent_map *em);
  60int __init extent_map_init(void);
  61void extent_map_exit(void);
  62int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len);
  63struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
  64                                         u64 start, u64 len);
  65#endif
  66