root/include/linux/dqblk_qtree.h

INCLUDED FROM

DEFINITIONS

1. qtree_depth

/*
 *      Definitions of structures and functions for quota formats using trie
 */

#ifndef _LINUX_DQBLK_QTREE_H
#define _LINUX_DQBLK_QTREE_H

#include <linux/types.h>

/* Numbers of blocks needed for updates - we count with the smallest
 * possible block size (1024) */
#define QTREE_INIT_ALLOC 4
#define QTREE_INIT_REWRITE 2
#define QTREE_DEL_ALLOC 0
#define QTREE_DEL_REWRITE 6

struct dquot;

/* Operations */
struct qtree_fmt_operations {
        void (*mem2disk_dqblk)(void *disk, struct dquot *dquot);        /* Convert given entry from in memory format to disk one */
        void (*disk2mem_dqblk)(struct dquot *dquot, void *disk);        /* Convert given entry from disk format to in memory one */
        int (*is_id)(void *disk, struct dquot *dquot);  /* Is this structure for given id? */
};

/* Inmemory copy of version specific information */
struct qtree_mem_dqinfo {
        struct super_block *dqi_sb;     /* Sb quota is on */
        int dqi_type;                   /* Quota type */
        unsigned int dqi_blocks;        /* # of blocks in quota file */
        unsigned int dqi_free_blk;      /* First block in list of free blocks */
        unsigned int dqi_free_entry;    /* First block with free entry */
        unsigned int dqi_blocksize_bits;        /* Block size of quota file */
        unsigned int dqi_entry_size;    /* Size of quota entry in quota file */
        unsigned int dqi_usable_bs;     /* Space usable in block for quota data */
        unsigned int dqi_qtree_depth;   /* Precomputed depth of quota tree */
        struct qtree_fmt_operations *dqi_ops;   /* Operations for entry manipulation */
};

int qtree_write_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot);
int qtree_read_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot);
int qtree_delete_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot);
int qtree_release_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot);
int qtree_entry_unused(struct qtree_mem_dqinfo *info, char *disk);
static inline int qtree_depth(struct qtree_mem_dqinfo *info)
{
        unsigned int epb = info->dqi_usable_bs >> 2;
        unsigned long long entries = epb;
        int i;

        for (i = 1; entries < (1ULL << 32); i++)
                entries *= epb;
        return i;
}

#endif /* _LINUX_DQBLK_QTREE_H */