1 /* SPDX-License-Identifier: GPL-2.0 */ 2 3 #ifndef BTRFS_EXTENT_MAP_H 4 #define BTRFS_EXTENT_MAP_H 5 6 #include <linux/compiler_types.h> 7 #include <linux/rwlock_types.h> 8 #include <linux/rbtree.h> 9 #include <linux/list.h> 10 #include <linux/refcount.h> 11 #include "misc.h" 12 #include "extent_map.h" 13 #include "compression.h" 14 15 struct btrfs_inode; 16 struct btrfs_fs_info; 17 18 #define EXTENT_MAP_LAST_BYTE ((u64)-4) 19 #define EXTENT_MAP_HOLE ((u64)-3) 20 #define EXTENT_MAP_INLINE ((u64)-2) 21 22 /* bits for the extent_map::flags field */ 23 enum { 24 /* this entry not yet on disk, don't free it */ 25 ENUM_BIT(EXTENT_FLAG_PINNED), 26 ENUM_BIT(EXTENT_FLAG_COMPRESS_ZLIB), 27 ENUM_BIT(EXTENT_FLAG_COMPRESS_LZO), 28 ENUM_BIT(EXTENT_FLAG_COMPRESS_ZSTD), 29 /* pre-allocated extent */ 30 ENUM_BIT(EXTENT_FLAG_PREALLOC), 31 /* Logging this extent */ 32 ENUM_BIT(EXTENT_FLAG_LOGGING), 33 /* Filling in a preallocated extent */ 34 ENUM_BIT(EXTENT_FLAG_FILLING), 35 /* This em is merged from two or more physically adjacent ems */ 36 ENUM_BIT(EXTENT_FLAG_MERGED), 37 }; 38 39 /* 40 * Keep this structure as compact as possible, as we can have really large 41 * amounts of allocated extent maps at any time. 42 */ 43 struct extent_map { 44 struct rb_node rb_node; 45 46 /* all of these are in bytes */ 47 u64 start; 48 u64 len; 49 u64 mod_start; 50 u64 mod_len; 51 u64 orig_start; 52 u64 orig_block_len; 53 u64 ram_bytes; 54 u64 block_start; 55 u64 block_len; 56 57 /* 58 * Generation of the extent map, for merged em it's the highest 59 * generation of all merged ems. 60 * For non-merged extents, it's from btrfs_file_extent_item::generation. 61 */ 62 u64 generation; 63 u32 flags; 64 refcount_t refs; 65 struct list_head list; 66 }; 67 68 struct extent_map_tree { 69 struct rb_root_cached map; 70 struct list_head modified_extents; 71 rwlock_t lock; 72 }; 73 74 struct btrfs_inode; 75 76 static inline void extent_map_set_compression(struct extent_map *em, 77 enum btrfs_compression_type type) 78 { 79 if (type == BTRFS_COMPRESS_ZLIB) 80 em->flags |= EXTENT_FLAG_COMPRESS_ZLIB; 81 else if (type == BTRFS_COMPRESS_LZO) 82 em->flags |= EXTENT_FLAG_COMPRESS_LZO; 83 else if (type == BTRFS_COMPRESS_ZSTD) 84 em->flags |= EXTENT_FLAG_COMPRESS_ZSTD; 85 } 86 87 static inline enum btrfs_compression_type extent_map_compression(const struct extent_map *em) 88 { 89 if (em->flags & EXTENT_FLAG_COMPRESS_ZLIB) 90 return BTRFS_COMPRESS_ZLIB; 91 92 if (em->flags & EXTENT_FLAG_COMPRESS_LZO) 93 return BTRFS_COMPRESS_LZO; 94 95 if (em->flags & EXTENT_FLAG_COMPRESS_ZSTD) 96 return BTRFS_COMPRESS_ZSTD; 97 98 return BTRFS_COMPRESS_NONE; 99 } 100 101 /* 102 * More efficient way to determine if extent is compressed, instead of using 103 * 'extent_map_compression() != BTRFS_COMPRESS_NONE'. 104 */ 105 static inline bool extent_map_is_compressed(const struct extent_map *em) 106 { 107 return (em->flags & (EXTENT_FLAG_COMPRESS_ZLIB | 108 EXTENT_FLAG_COMPRESS_LZO | 109 EXTENT_FLAG_COMPRESS_ZSTD)) != 0; 110 } 111 112 static inline int extent_map_in_tree(const struct extent_map *em) 113 { 114 return !RB_EMPTY_NODE(&em->rb_node); 115 } 116 117 static inline u64 extent_map_end(const struct extent_map *em) 118 { 119 if (em->start + em->len < em->start) 120 return (u64)-1; 121 return em->start + em->len; 122 } 123 124 void extent_map_tree_init(struct extent_map_tree *tree); 125 struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree, 126 u64 start, u64 len); 127 void remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em); 128 int split_extent_map(struct btrfs_inode *inode, u64 start, u64 len, u64 pre, 129 u64 new_logical); 130 131 struct extent_map *alloc_extent_map(void); 132 void free_extent_map(struct extent_map *em); 133 int __init extent_map_init(void); 134 void __cold extent_map_exit(void); 135 int unpin_extent_cache(struct btrfs_inode *inode, u64 start, u64 len, u64 gen); 136 void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em); 137 struct extent_map *search_extent_mapping(struct extent_map_tree *tree, 138 u64 start, u64 len); 139 int btrfs_add_extent_mapping(struct btrfs_fs_info *fs_info, 140 struct extent_map_tree *em_tree, 141 struct extent_map **em_in, u64 start, u64 len); 142 void btrfs_drop_extent_map_range(struct btrfs_inode *inode, 143 u64 start, u64 end, 144 bool skip_pinned); 145 int btrfs_replace_extent_map_range(struct btrfs_inode *inode, 146 struct extent_map *new_em, 147 bool modified); 148 149 #endif 150