include/linux/dqblk_qtree.h

   1 /*
   2  *      Definitions of structures and functions for quota formats using trie
   3  */
   4
   5 #ifndef _LINUX_DQBLK_QTREE_H
   6 #define _LINUX_DQBLK_QTREE_H
   7
   8 #include <linux/types.h>
   9
  10 /* Numbers of blocks needed for updates - we count with the smallest
  11  * possible block size (1024) */
  12 #define QTREE_INIT_ALLOC 4
  13 #define QTREE_INIT_REWRITE 2
  14 #define QTREE_DEL_ALLOC 0
  15 #define QTREE_DEL_REWRITE 6
  16
  17 struct dquot;
  18
  19 /* Operations */
  20 struct qtree_fmt_operations {
  21         void (*mem2disk_dqblk)(void *disk, struct dquot *dquot);        /* Convert given entry from in memory format to disk one */
  22         void (*disk2mem_dqblk)(struct dquot *dquot, void *disk);        /* Convert given entry from disk format to in memory one */
  23         int (*is_id)(void *disk, struct dquot *dquot);  /* Is this structure for given id? */
  24 };
  25
  26 /* Inmemory copy of version specific information */
  27 struct qtree_mem_dqinfo {
  28         struct super_block *dqi_sb;     /* Sb quota is on */
  29         int dqi_type;                   /* Quota type */
  30         unsigned int dqi_blocks;        /* # of blocks in quota file */
  31         unsigned int dqi_free_blk;      /* First block in list of free blocks */
  32         unsigned int dqi_free_entry;    /* First block with free entry */
  33         unsigned int dqi_blocksize_bits;        /* Block size of quota file */
  34         unsigned int dqi_entry_size;    /* Size of quota entry in quota file */
  35         unsigned int dqi_usable_bs;     /* Space usable in block for quota data */
  36         unsigned int dqi_qtree_depth;   /* Precomputed depth of quota tree */
  37         struct qtree_fmt_operations *dqi_ops;   /* Operations for entry manipulation */
  38 };
  39
  40 int qtree_write_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot);
  41 int qtree_read_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot);
  42 int qtree_delete_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot);
  43 int qtree_release_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot);
  44 int qtree_entry_unused(struct qtree_mem_dqinfo *info, char *disk);
  45 static inline int qtree_depth(struct qtree_mem_dqinfo *info)
  46 {
  47         unsigned int epb = info->dqi_usable_bs >> 2;
  48         unsigned long long entries = epb;
  49         int i;
  50
  51         for (i = 1; entries < (1ULL << 32); i++)
  52                 entries *= epb;
  53         return i;
  54 }
  55
  56 #endif /* _LINUX_DQBLK_QTREE_H */