minix/servers/vm/cache.h

   1
   2 struct cached_page {
   3         /*  - The (dev, dev_offset) pair are unique;
   4          *    the (ino, ino_offset) pair is information and
   5          *    might be missing. duplicate do not make sense
   6          *    although it won't bother VM much.
   7          *  - dev must always be valid, i.e. not NO_DEV
   8          *  - ino may be unknown, i.e. VMC_NO_INODE
   9          */
  10         dev_t dev;                      /* which dev is it on */
  11         u64_t dev_offset;               /* offset within dev */
  12
  13         ino_t ino;                      /* which ino is it about */
  14         u64_t ino_offset;               /* offset within ino */
  15         int flags;                      /* currently only VMSF_ONCE or 0 */
  16         struct phys_block *page;        /* page ptr */
  17         struct cached_page *older;      /* older in lru chain */
  18         struct cached_page *newer;      /* newer in lru chain */
  19         struct cached_page *hash_next_dev; /* next in hash chain (bydev) */
  20         struct cached_page *hash_next_ino; /* next in hash chain (byino) */
  21 };
  22