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kernel/linux-imx6_3.14.28/fs/btrfs/extent_map.h 2.12 KB
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  #ifndef __EXTENTMAP__
  #define __EXTENTMAP__
  
  #include <linux/rbtree.h>
  
  #define EXTENT_MAP_LAST_BYTE ((u64)-4)
  #define EXTENT_MAP_HOLE ((u64)-3)
  #define EXTENT_MAP_INLINE ((u64)-2)
  #define EXTENT_MAP_DELALLOC ((u64)-1)
  
  /* bits for the flags field */
  #define EXTENT_FLAG_PINNED 0 /* this entry not yet on disk, don't free it */
  #define EXTENT_FLAG_COMPRESSED 1
  #define EXTENT_FLAG_VACANCY 2 /* no file extent item found */
  #define EXTENT_FLAG_PREALLOC 3 /* pre-allocated extent */
  #define EXTENT_FLAG_LOGGING 4 /* Logging this extent */
  #define EXTENT_FLAG_FILLING 5 /* Filling in a preallocated extent */
  
  struct extent_map {
  	struct rb_node rb_node;
  
  	/* all of these are in bytes */
  	u64 start;
  	u64 len;
  	u64 mod_start;
  	u64 mod_len;
  	u64 orig_start;
  	u64 orig_block_len;
  	u64 ram_bytes;
  	u64 block_start;
  	u64 block_len;
  	u64 generation;
  	unsigned long flags;
  	struct block_device *bdev;
  	atomic_t refs;
  	unsigned int in_tree;
  	unsigned int compress_type;
  	struct list_head list;
  };
  
  struct extent_map_tree {
  	struct rb_root map;
  	struct list_head modified_extents;
  	rwlock_t lock;
  };
  
  static inline u64 extent_map_end(struct extent_map *em)
  {
  	if (em->start + em->len < em->start)
  		return (u64)-1;
  	return em->start + em->len;
  }
  
  static inline u64 extent_map_block_end(struct extent_map *em)
  {
  	if (em->block_start + em->block_len < em->block_start)
  		return (u64)-1;
  	return em->block_start + em->block_len;
  }
  
  void extent_map_tree_init(struct extent_map_tree *tree);
  struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
  					 u64 start, u64 len);
  int add_extent_mapping(struct extent_map_tree *tree,
  		       struct extent_map *em, int modified);
  int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
  
  struct extent_map *alloc_extent_map(void);
  void free_extent_map(struct extent_map *em);
  int __init extent_map_init(void);
  void extent_map_exit(void);
  int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len, u64 gen);
  void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em);
  struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
  					 u64 start, u64 len);
  #endif