LXR linux/fs/btrfs/extent

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef __EXTENTMAP__
   3#define __EXTENTMAP__
   4
   5#include <linux/rbtree.h>
   6#include <linux/refcount.h>
   7
   8#define EXTENT_MAP_LAST_BYTE ((u64)-4)
   9#define EXTENT_MAP_HOLE ((u64)-3)
  10#define EXTENT_MAP_INLINE ((u64)-2)
  11#define EXTENT_MAP_DELALLOC ((u64)-1)
  12
  13/* bits for the flags field */
  14#define EXTENT_FLAG_PINNED 0 /* this entry not yet on disk, don't free it */
  15#define EXTENT_FLAG_COMPRESSED 1
  16#define EXTENT_FLAG_VACANCY 2 /* no file extent item found */
  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
  22struct 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
  51struct extent_map_tree {
  52        struct rb_root map;
  53        struct list_head modified_extents;
  54        rwlock_t lock;
  55};
  56
  57static inline int extent_map_in_tree(const struct extent_map *em)
  58{
  59        return !RB_EMPTY_NODE(&em->rb_node);
  60}
  61
  62static 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
  69static 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
  76void extent_map_tree_init(struct extent_map_tree *tree);
  77struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
  78                                         u64 start, u64 len);
  79int add_extent_mapping(struct extent_map_tree *tree,
  80                       struct extent_map *em, int modified);
  81int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
  82void replace_extent_mapping(struct extent_map_tree *tree,
  83                            struct extent_map *cur,
  84                            struct extent_map *new,
  85                            int modified);
  86
  87struct extent_map *alloc_extent_map(void);
  88void free_extent_map(struct extent_map *em);
  89int __init extent_map_init(void);
  90void extent_map_exit(void);
  91int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len, u64 gen);
  92void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em);
  93struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
  94                                         u64 start, u64 len);
  95#endif
  96