LXR linux/fs/ext4/extents

   1/*
   2 *  fs/ext4/extents_status.h
   3 *
   4 * Written by Yongqiang Yang <xiaoqiangnk@gmail.com>
   5 * Modified by
   6 *      Allison Henderson <achender@linux.vnet.ibm.com>
   7 *      Zheng Liu <wenqing.lz@taobao.com>
   8 *
   9 */
  10
  11#ifndef _EXT4_EXTENTS_STATUS_H
  12#define _EXT4_EXTENTS_STATUS_H
  13
  14/*
  15 * Turn on ES_DEBUG__ to get lots of info about extent status operations.
  16 */
  17#ifdef ES_DEBUG__
  18#define es_debug(fmt, ...)      printk(fmt, ##__VA_ARGS__)
  19#else
  20#define es_debug(fmt, ...)      no_printk(fmt, ##__VA_ARGS__)
  21#endif
  22
  23/*
  24 * With ES_AGGRESSIVE_TEST defined, the result of es caching will be
  25 * checked with old map_block's result.
  26 */
  27#define ES_AGGRESSIVE_TEST__
  28
  29/*
  30 * These flags live in the high bits of extent_status.es_pblk
  31 */
  32#define ES_SHIFT        60
  33
  34#define EXTENT_STATUS_WRITTEN   (1 << 3)
  35#define EXTENT_STATUS_UNWRITTEN (1 << 2)
  36#define EXTENT_STATUS_DELAYED   (1 << 1)
  37#define EXTENT_STATUS_HOLE      (1 << 0)
  38
  39#define EXTENT_STATUS_FLAGS     (EXTENT_STATUS_WRITTEN | \
  40                                 EXTENT_STATUS_UNWRITTEN | \
  41                                 EXTENT_STATUS_DELAYED | \
  42                                 EXTENT_STATUS_HOLE)
  43
  44#define ES_WRITTEN              (1ULL << 63)
  45#define ES_UNWRITTEN            (1ULL << 62)
  46#define ES_DELAYED              (1ULL << 61)
  47#define ES_HOLE                 (1ULL << 60)
  48
  49#define ES_MASK                 (ES_WRITTEN | ES_UNWRITTEN | \
  50                                 ES_DELAYED | ES_HOLE)
  51
  52struct ext4_sb_info;
  53struct ext4_extent;
  54
  55struct extent_status {
  56        struct rb_node rb_node;
  57        ext4_lblk_t es_lblk;    /* first logical block extent covers */
  58        ext4_lblk_t es_len;     /* length of extent in block */
  59        ext4_fsblk_t es_pblk;   /* first physical block */
  60};
  61
  62struct ext4_es_tree {
  63        struct rb_root root;
  64        struct extent_status *cache_es; /* recently accessed extent */
  65};
  66
  67extern int __init ext4_init_es(void);
  68extern void ext4_exit_es(void);
  69extern void ext4_es_init_tree(struct ext4_es_tree *tree);
  70
  71extern int ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk,
  72                                 ext4_lblk_t len, ext4_fsblk_t pblk,
  73                                 unsigned int status);
  74extern void ext4_es_cache_extent(struct inode *inode, ext4_lblk_t lblk,
  75                                 ext4_lblk_t len, ext4_fsblk_t pblk,
  76                                 unsigned int status);
  77extern int ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
  78                                 ext4_lblk_t len);
  79extern void ext4_es_find_delayed_extent_range(struct inode *inode,
  80                                        ext4_lblk_t lblk, ext4_lblk_t end,
  81                                        struct extent_status *es);
  82extern int ext4_es_lookup_extent(struct inode *inode, ext4_lblk_t lblk,
  83                                 struct extent_status *es);
  84
  85static inline int ext4_es_is_written(struct extent_status *es)
  86{
  87        return (es->es_pblk & ES_WRITTEN) != 0;
  88}
  89
  90static inline int ext4_es_is_unwritten(struct extent_status *es)
  91{
  92        return (es->es_pblk & ES_UNWRITTEN) != 0;
  93}
  94
  95static inline int ext4_es_is_delayed(struct extent_status *es)
  96{
  97        return (es->es_pblk & ES_DELAYED) != 0;
  98}
  99
 100static inline int ext4_es_is_hole(struct extent_status *es)
 101{
 102        return (es->es_pblk & ES_HOLE) != 0;
 103}
 104
 105static inline unsigned int ext4_es_status(struct extent_status *es)
 106{
 107        return es->es_pblk >> ES_SHIFT;
 108}
 109
 110static inline ext4_fsblk_t ext4_es_pblock(struct extent_status *es)
 111{
 112        return es->es_pblk & ~ES_MASK;
 113}
 114
 115static inline void ext4_es_store_pblock(struct extent_status *es,
 116                                        ext4_fsblk_t pb)
 117{
 118        ext4_fsblk_t block;
 119
 120        block = (pb & ~ES_MASK) | (es->es_pblk & ES_MASK);
 121        es->es_pblk = block;
 122}
 123
 124static inline void ext4_es_store_status(struct extent_status *es,
 125                                        unsigned int status)
 126{
 127        es->es_pblk = (((ext4_fsblk_t)
 128                        (status & EXTENT_STATUS_FLAGS) << ES_SHIFT) |
 129                       (es->es_pblk & ~ES_MASK));
 130}
 131
 132extern void ext4_es_register_shrinker(struct ext4_sb_info *sbi);
 133extern void ext4_es_unregister_shrinker(struct ext4_sb_info *sbi);
 134extern void ext4_es_lru_add(struct inode *inode);
 135extern void ext4_es_lru_del(struct inode *inode);
 136
 137#endif /* _EXT4_EXTENTS_STATUS_H */
 138