1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 *	Definitions of structures and functions for quota formats using trie
4 */
5
6#ifndef _LINUX_DQBLK_QTREE_H
7#define _LINUX_DQBLK_QTREE_H
8
9#include <linux/types.h>
10
11/* Numbers of blocks needed for updates - we count with the smallest
12 * possible block size (1024) */
13#define QTREE_INIT_ALLOC 4
14#define QTREE_INIT_REWRITE 2
15#define QTREE_DEL_ALLOC 0
16#define QTREE_DEL_REWRITE 6
17
18struct dquot;
19struct kqid;
20
21/* Operations */
22struct qtree_fmt_operations {
23	void (*mem2disk_dqblk)(void *disk, struct dquot *dquot);	/* Convert given entry from in memory format to disk one */
24	void (*disk2mem_dqblk)(struct dquot *dquot, void *disk);	/* Convert given entry from disk format to in memory one */
25	int (*is_id)(void *disk, struct dquot *dquot);	/* Is this structure for given id? */
26};
27
28/* Inmemory copy of version specific information */
29struct qtree_mem_dqinfo {
30	struct super_block *dqi_sb;	/* Sb quota is on */
31	int dqi_type;			/* Quota type */
32	unsigned int dqi_blocks;	/* # of blocks in quota file */
33	unsigned int dqi_free_blk;	/* First block in list of free blocks */
34	unsigned int dqi_free_entry;	/* First block with free entry */
35	unsigned int dqi_blocksize_bits;	/* Block size of quota file */
36	unsigned int dqi_entry_size;	/* Size of quota entry in quota file */
37	unsigned int dqi_usable_bs;	/* Space usable in block for quota data */
38	unsigned int dqi_qtree_depth;	/* Precomputed depth of quota tree */
39	const struct qtree_fmt_operations *dqi_ops; /* Operations for entry manipulation */
40};
41
42int qtree_write_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot);
43int qtree_read_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot);
44int qtree_delete_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot);
45int qtree_release_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot);
46int qtree_entry_unused(struct qtree_mem_dqinfo *info, char *disk);
47static inline int qtree_depth(struct qtree_mem_dqinfo *info)
48{
49	unsigned int epb = info->dqi_usable_bs >> 2;
50	unsigned long long entries = epb;
51	int i;
52
53	for (i = 1; entries < (1ULL << 32); i++)
54		entries *= epb;
55	return i;
56}
57int qtree_get_next_id(struct qtree_mem_dqinfo *info, struct kqid *qid);
58
59#endif /* _LINUX_DQBLK_QTREE_H */
60