include/linux/dqblk_qtree.h

   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);
  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 */