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 /* used only during fiemap calls */ 13 #define EXTENT_MAP_DELALLOC ((u64)-1) 14 15 /* bits for the extent_map::flags field */ 16 enum { 17 /* this entry not yet on disk, don't free it */ 18 EXTENT_FLAG_PINNED, 19 EXTENT_FLAG_COMPRESSED, 20 /* pre-allocated extent */ 21 EXTENT_FLAG_PREALLOC, 22 /* Logging this extent */ 23 EXTENT_FLAG_LOGGING, 24 /* Filling in a preallocated extent */ 25 EXTENT_FLAG_FILLING, 26 /* filesystem extent mapping type */ 27 EXTENT_FLAG_FS_MAPPING, 28 /* This em is merged from two or more physically adjacent ems */ 29 EXTENT_FLAG_MERGED, 30 }; 31 32 struct extent_map { 33 struct rb_node rb_node; 34 35 /* all of these are in bytes */ 36 u64 start; 37 u64 len; 38 u64 mod_start; 39 u64 mod_len; 40 u64 orig_start; 41 u64 orig_block_len; 42 u64 ram_bytes; 43 u64 block_start; 44 u64 block_len; 45 46 /* 47 * Generation of the extent map, for merged em it's the highest 48 * generation of all merged ems. 49 * For non-merged extents, it's from btrfs_file_extent_item::generation. 50 */ 51 u64 generation; 52 unsigned long flags; 53 /* Used for chunk mappings, flag EXTENT_FLAG_FS_MAPPING must be set */ 54 struct map_lookup *map_lookup; 55 refcount_t refs; 56 unsigned int compress_type; 57 struct list_head list; 58 }; 59 60 struct extent_map_tree { 61 struct rb_root_cached map; 62 struct list_head modified_extents; 63 rwlock_t lock; 64 }; 65 66 static inline int extent_map_in_tree(const struct extent_map *em) 67 { 68 return !RB_EMPTY_NODE(&em->rb_node); 69 } 70 71 static inline u64 extent_map_end(struct extent_map *em) 72 { 73 if (em->start + em->len < em->start) 74 return (u64)-1; 75 return em->start + em->len; 76 } 77 78 static inline u64 extent_map_block_end(struct extent_map *em) 79 { 80 if (em->block_start + em->block_len < em->block_start) 81 return (u64)-1; 82 return em->block_start + em->block_len; 83 } 84 85 void extent_map_tree_init(struct extent_map_tree *tree); 86 struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree, 87 u64 start, u64 len); 88 int add_extent_mapping(struct extent_map_tree *tree, 89 struct extent_map *em, int modified); 90 void remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em); 91 void replace_extent_mapping(struct extent_map_tree *tree, 92 struct extent_map *cur, 93 struct extent_map *new, 94 int modified); 95 96 struct extent_map *alloc_extent_map(void); 97 void free_extent_map(struct extent_map *em); 98 int __init extent_map_init(void); 99 void __cold extent_map_exit(void); 100 int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len, u64 gen); 101 void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em); 102 struct extent_map *search_extent_mapping(struct extent_map_tree *tree, 103 u64 start, u64 len); 104 int btrfs_add_extent_mapping(struct btrfs_fs_info *fs_info, 105 struct extent_map_tree *em_tree, 106 struct extent_map **em_in, u64 start, u64 len); 107 108 #endif 109