extent_map.h 2.7 KB

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  1. /* SPDX-License-Identifier: GPL-2.0 */
  2. #ifndef BTRFS_EXTENT_MAP_H
  3. #define BTRFS_EXTENT_MAP_H
  4. #include <linux/rbtree.h>
  5. #include <linux/refcount.h>
  6. #define EXTENT_MAP_LAST_BYTE ((u64)-4)
  7. #define EXTENT_MAP_HOLE ((u64)-3)
  8. #define EXTENT_MAP_INLINE ((u64)-2)
  9. /* used only during fiemap calls */
  10. #define EXTENT_MAP_DELALLOC ((u64)-1)
  11. /* bits for the extent_map::flags field */
  12. enum {
  13. /* this entry not yet on disk, don't free it */
  14. EXTENT_FLAG_PINNED,
  15. EXTENT_FLAG_COMPRESSED,
  16. /* pre-allocated extent */
  17. EXTENT_FLAG_PREALLOC,
  18. /* Logging this extent */
  19. EXTENT_FLAG_LOGGING,
  20. /* Filling in a preallocated extent */
  21. EXTENT_FLAG_FILLING,
  22. /* filesystem extent mapping type */
  23. EXTENT_FLAG_FS_MAPPING,
  24. };
  25. struct extent_map {
  26. struct rb_node rb_node;
  27. /* all of these are in bytes */
  28. u64 start;
  29. u64 len;
  30. u64 mod_start;
  31. u64 mod_len;
  32. u64 orig_start;
  33. u64 orig_block_len;
  34. u64 ram_bytes;
  35. u64 block_start;
  36. u64 block_len;
  37. u64 generation;
  38. unsigned long flags;
  39. /* Used for chunk mappings, flag EXTENT_FLAG_FS_MAPPING must be set */
  40. struct map_lookup *map_lookup;
  41. refcount_t refs;
  42. unsigned int compress_type;
  43. struct list_head list;
  44. };
  45. struct extent_map_tree {
  46. struct rb_root_cached map;
  47. struct list_head modified_extents;
  48. rwlock_t lock;
  49. };
  50. static inline int extent_map_in_tree(const struct extent_map *em)
  51. {
  52. return !RB_EMPTY_NODE(&em->rb_node);
  53. }
  54. static inline u64 extent_map_end(struct extent_map *em)
  55. {
  56. if (em->start + em->len < em->start)
  57. return (u64)-1;
  58. return em->start + em->len;
  59. }
  60. static inline u64 extent_map_block_end(struct extent_map *em)
  61. {
  62. if (em->block_start + em->block_len < em->block_start)
  63. return (u64)-1;
  64. return em->block_start + em->block_len;
  65. }
  66. void extent_map_tree_init(struct extent_map_tree *tree);
  67. struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
  68. u64 start, u64 len);
  69. int add_extent_mapping(struct extent_map_tree *tree,
  70. struct extent_map *em, int modified);
  71. void remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
  72. void replace_extent_mapping(struct extent_map_tree *tree,
  73. struct extent_map *cur,
  74. struct extent_map *new,
  75. int modified);
  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 __cold 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. int btrfs_add_extent_mapping(struct btrfs_fs_info *fs_info,
  85. struct extent_map_tree *em_tree,
  86. struct extent_map **em_in, u64 start, u64 len);
  87. #endif