/* SPDX-License-Identifier: GPL-2.0 */

  /*
   *	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;

  struct kqid;

  
  /* 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 */

  	const 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;
  }

  int qtree_get_next_id(struct qtree_mem_dqinfo *info, struct kqid *qid);

  
  #endif /* _LINUX_DQBLK_QTREE_H */