fs/btrfs/extent_map.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2
   3 #ifndef BTRFS_EXTENT_MAP_H
   4 #define BTRFS_EXTENT_MAP_H
   5
   6 #include <linux/rbtree.h>
   7 #include <linux/refcount.h>
   8
   9 #define EXTENT_MAP_LAST_BYTE ((u64)-4)
  10 #define EXTENT_MAP_HOLE ((u64)-3)
  11 #define EXTENT_MAP_INLINE ((u64)-2)
  12 #define EXTENT_MAP_DELALLOC ((u64)-1)
  13
  14 /* bits for the flags field */
  15 #define EXTENT_FLAG_PINNED 0 /* this entry not yet on disk, don't free it */
  16 #define EXTENT_FLAG_COMPRESSED 1
  17 #define EXTENT_FLAG_PREALLOC 3 /* pre-allocated extent */
  18 #define EXTENT_FLAG_LOGGING 4 /* Logging this extent */
  19 #define EXTENT_FLAG_FILLING 5 /* Filling in a preallocated extent */
  20 #define EXTENT_FLAG_FS_MAPPING 6 /* filesystem extent mapping type */
  21
  22 struct extent_map {
  23         struct rb_node rb_node;
  24
  25         /* all of these are in bytes */
  26         u64 start;
  27         u64 len;
  28         u64 mod_start;
  29         u64 mod_len;
  30         u64 orig_start;
  31         u64 orig_block_len;
  32         u64 ram_bytes;
  33         u64 block_start;
  34         u64 block_len;
  35         u64 generation;
  36         unsigned long flags;
  37         union {
  38                 struct block_device *bdev;
  39
  40                 /*
  41                  * used for chunk mappings
  42                  * flags & EXTENT_FLAG_FS_MAPPING must be set
  43                  */
  44                 struct map_lookup *map_lookup;
  45         };
  46         refcount_t refs;
  47         unsigned int compress_type;
  48         struct list_head list;
  49 };
  50
  51 struct extent_map_tree {
  52         struct rb_root map;
  53         struct list_head modified_extents;
  54         rwlock_t lock;
  55 };
  56
  57 static inline int extent_map_in_tree(const struct extent_map *em)
  58 {
  59         return !RB_EMPTY_NODE(&em->rb_node);
  60 }
  61
  62 static inline u64 extent_map_end(struct extent_map *em)
  63 {
  64         if (em->start + em->len < em->start)
  65                 return (u64)-1;
  66         return em->start + em->len;
  67 }
  68
  69 static inline u64 extent_map_block_end(struct extent_map *em)
  70 {
  71         if (em->block_start + em->block_len < em->block_start)
  72                 return (u64)-1;
  73         return em->block_start + em->block_len;
  74 }
  75
  76 void extent_map_tree_init(struct extent_map_tree *tree);
  77 struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
  78                                          u64 start, u64 len);
  79 int add_extent_mapping(struct extent_map_tree *tree,
  80                        struct extent_map *em, int modified);
  81 int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
  82 void replace_extent_mapping(struct extent_map_tree *tree,
  83                             struct extent_map *cur,
  84                             struct extent_map *new,
  85                             int modified);
  86
  87 struct extent_map *alloc_extent_map(void);
  88 void free_extent_map(struct extent_map *em);
  89 int __init extent_map_init(void);
  90 void __cold extent_map_exit(void);
  91 int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len, u64 gen);
  92 void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em);
  93 struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
  94                                          u64 start, u64 len);
  95 int btrfs_add_extent_mapping(struct extent_map_tree *em_tree,
  96                              struct extent_map **em_in, u64 start, u64 len);
  97
  98 #endif