xref: /linux/include/linux/dqblk_qtree.h (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
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 */
57