fs/ext4/extents_status.h

   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 struct extent_status {
  24         struct rb_node rb_node;
  25         ext4_lblk_t start;      /* first block extent covers */
  26         ext4_lblk_t len;        /* length of extent in block */
  27 };
  28
  29 struct ext4_es_tree {
  30         struct rb_root root;
  31         struct extent_status *cache_es; /* recently accessed extent */
  32 };
  33
  34 extern int __init ext4_init_es(void);
  35 extern void ext4_exit_es(void);
  36 extern void ext4_es_init_tree(struct ext4_es_tree *tree);
  37
  38 extern int ext4_es_insert_extent(struct inode *inode, ext4_lblk_t start,
  39                                  ext4_lblk_t len);
  40 extern int ext4_es_remove_extent(struct inode *inode, ext4_lblk_t start,
  41                                  ext4_lblk_t len);
  42 extern ext4_lblk_t ext4_es_find_extent(struct inode *inode,
  43                                 struct extent_status *es);
  44
  45 #endif /* _EXT4_EXTENTS_STATUS_H */