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_PREALLOC 3 /* pre-allocated extent */
  17#define EXTENT_FLAG_LOGGING 4 /* Logging this extent */
  18#define EXTENT_FLAG_FILLING 5 /* Filling in a preallocated extent */
  19#define EXTENT_FLAG_FS_MAPPING 6 /* filesystem extent mapping type */
  20
  21struct extent_map {
  22        struct rb_node rb_node;
  23
  24        /* all of these are in bytes */
  25        u64 start;
  26        u64 len;
  27        u64 mod_start;
  28        u64 mod_len;
  29        u64 orig_start;
  30        u64 orig_block_len;
  31        u64 ram_bytes;
  32        u64 block_start;
  33        u64 block_len;
  34        u64 generation;
  35        unsigned long flags;
  36        union {
  37                struct block_device *bdev;
  38
  39                /*
  40                 * used for chunk mappings
  41                 * flags & EXTENT_FLAG_FS_MAPPING must be set
  42                 */
  43                struct map_lookup *map_lookup;
  44        };
  45        refcount_t refs;
  46        unsigned int compress_type;
  47        struct list_head list;
  48};
  49
  50struct extent_map_tree {
  51        struct rb_root map;
  52        struct list_head modified_extents;
  53        rwlock_t lock;
  54};
  55
  56static inline int extent_map_in_tree(const struct extent_map *em)
  57{
  58        return !RB_EMPTY_NODE(&em->rb_node);
  59}
  60
  61static inline u64 extent_map_end(struct extent_map *em)
  62{
  63        if (em->start + em->len < em->start)
  64                return (u64)-1;
  65        return em->start + em->len;
  66}
  67
  68static inline u64 extent_map_block_end(struct extent_map *em)
  69{
  70        if (em->block_start + em->block_len < em->block_start)
  71                return (u64)-1;
  72        return em->block_start + em->block_len;
  73}
  74
  75void extent_map_tree_init(struct extent_map_tree *tree);
  76struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
  77                                         u64 start, u64 len);
  78int add_extent_mapping(struct extent_map_tree *tree,
  79                       struct extent_map *em, int modified);
  80int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
  81void replace_extent_mapping(struct extent_map_tree *tree,
  82                            struct extent_map *cur,
  83                            struct extent_map *new,
  84                            int modified);
  85
  86struct extent_map *alloc_extent_map(void);
  87void free_extent_map(struct extent_map *em);
  88int __init extent_map_init(void);
  89void extent_map_exit(void);
  90int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len, u64 gen);
  91void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em);
  92struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
  93                                         u64 start, u64 len);
  94int btrfs_add_extent_mapping(struct extent_map_tree *em_tree,
  95                             struct extent_map **em_in, u64 start, u64 len);
  96#endif
  97