LXR linux/fs/btrfs/extent

   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 */
  16enum {
  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};
  29
  30struct extent_map {
  31        struct rb_node rb_node;
  32
  33        /* all of these are in bytes */
  34        u64 start;
  35        u64 len;
  36        u64 mod_start;
  37        u64 mod_len;
  38        u64 orig_start;
  39        u64 orig_block_len;
  40        u64 ram_bytes;
  41        u64 block_start;
  42        u64 block_len;
  43        u64 generation;
  44        unsigned long flags;
  45        union {
  46                struct block_device *bdev;
  47
  48                /*
  49                 * used for chunk mappings
  50                 * flags & EXTENT_FLAG_FS_MAPPING must be set
  51                 */
  52                struct map_lookup *map_lookup;
  53        };
  54        refcount_t refs;
  55        unsigned int compress_type;
  56        struct list_head list;
  57};
  58
  59struct extent_map_tree {
  60        struct rb_root_cached map;
  61        struct list_head modified_extents;
  62        rwlock_t lock;
  63};
  64
  65static inline int extent_map_in_tree(const struct extent_map *em)
  66{
  67        return !RB_EMPTY_NODE(&em->rb_node);
  68}
  69
  70static inline u64 extent_map_end(struct extent_map *em)
  71{
  72        if (em->start + em->len < em->start)
  73                return (u64)-1;
  74        return em->start + em->len;
  75}
  76
  77static inline u64 extent_map_block_end(struct extent_map *em)
  78{
  79        if (em->block_start + em->block_len < em->block_start)
  80                return (u64)-1;
  81        return em->block_start + em->block_len;
  82}
  83
  84void extent_map_tree_init(struct extent_map_tree *tree);
  85struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
  86                                         u64 start, u64 len);
  87int add_extent_mapping(struct extent_map_tree *tree,
  88                       struct extent_map *em, int modified);
  89void remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
  90void replace_extent_mapping(struct extent_map_tree *tree,
  91                            struct extent_map *cur,
  92                            struct extent_map *new,
  93                            int modified);
  94
  95struct extent_map *alloc_extent_map(void);
  96void free_extent_map(struct extent_map *em);
  97int __init extent_map_init(void);
  98void __cold extent_map_exit(void);
  99int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len, u64 gen);
 100void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em);
 101struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
 102                                         u64 start, u64 len);
 103int btrfs_add_extent_mapping(struct btrfs_fs_info *fs_info,
 104                             struct extent_map_tree *em_tree,
 105                             struct extent_map **em_in, u64 start, u64 len);
 106
 107#endif
 108