fs/reiser4/readahead.h

   1 /* Copyright 2001, 2002, 2003 by Hans Reiser, licensing governed by reiser4/README */
   2
   3 #ifndef __READAHEAD_H__
   4 #define __READAHEAD_H__
   5
   6 #include "key.h"
   7
   8 typedef enum {
   9         RA_ADJACENT_ONLY = 1,   /* only requests nodes which are adjacent.
  10                                    Default is NO (not only adjacent) */
  11 } ra_global_flags;
  12
  13 /* reiser4 super block has a field of this type.
  14    It controls readahead during tree traversals */
  15 struct formatted_ra_params {
  16         unsigned long max;      /* request not more than this amount of nodes.
  17                                    Default is totalram_pages / 4 */
  18         int flags;
  19 };
  20
  21 typedef struct {
  22         reiser4_key key_to_stop;
  23 } ra_info_t;
  24
  25 void formatted_readahead(znode *, ra_info_t *);
  26 void reiser4_init_ra_info(ra_info_t * rai);
  27
  28 struct reiser4_file_ra_state {
  29         loff_t start;           /* Current window */
  30         loff_t size;
  31         loff_t next_size;       /* Next window size */
  32         loff_t ahead_start;     /* Ahead window */
  33         loff_t ahead_size;
  34         loff_t max_window_size; /* Maximum readahead window */
  35         loff_t slow_start;      /* enlarging r/a size algorithm. */
  36 };
  37
  38 extern void reiser4_readdir_readahead_init(struct inode *dir, tap_t * tap);
  39
  40 /* __READAHEAD_H__ */
  41 #endif
  42
  43 /*
  44    Local variables:
  45    c-indentation-style: "K&R"
  46    mode-name: "LC"
  47    c-basic-offset: 8
  48    tab-width: 8
  49    fill-column: 120
  50    End:
  51 */