Line data    Source code

       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             : struct btrfs_inode;
      67             : 
      68             : static inline int extent_map_in_tree(const struct extent_map *em)
      69             : {
      70           0 :         return !RB_EMPTY_NODE(&em->rb_node);
      71             : }
      72             : 
      73             : static inline u64 extent_map_end(struct extent_map *em)
      74             : {
      75           0 :         if (em->start + em->len < em->start)
      76           0 :                 return (u64)-1;
      77             :         return em->start + em->len;
      78             : }
      79             : 
      80             : static inline u64 extent_map_block_end(struct extent_map *em)
      81             : {
      82           0 :         if (em->block_start + em->block_len < em->block_start)
      83           0 :                 return (u64)-1;
      84             :         return em->block_start + em->block_len;
      85             : }
      86             : 
      87             : void extent_map_tree_init(struct extent_map_tree *tree);
      88             : struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
      89             :                                          u64 start, u64 len);
      90             : int add_extent_mapping(struct extent_map_tree *tree,
      91             :                        struct extent_map *em, int modified);
      92             : void remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
      93             : int split_extent_map(struct btrfs_inode *inode, u64 start, u64 len, u64 pre,
      94             :                      u64 new_logical);
      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             : void btrfs_drop_extent_map_range(struct btrfs_inode *inode,
     108             :                                  u64 start, u64 end,
     109             :                                  bool skip_pinned);
     110             : int btrfs_replace_extent_map_range(struct btrfs_inode *inode,
     111             :                                    struct extent_map *new_em,
     112             :                                    bool modified);
     113             : 
     114             : #endif