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 
18 struct dquot;
19 struct kqid;
20 
21 /* Operations */
22 struct 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 */
29 struct 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 
42 int qtree_write_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot);
43 int qtree_read_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot);
44 int qtree_delete_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot);
45 int qtree_release_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot);
46 int qtree_entry_unused(struct qtree_mem_dqinfo *info, char *disk);
qtree_depth(struct qtree_mem_dqinfo * info)47 static 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 }
57 int qtree_get_next_id(struct qtree_mem_dqinfo *info, struct kqid *qid);
58 
59 #endif /* _LINUX_DQBLK_QTREE_H */
60