LXR linux/fs/nilfs2/alloc.h

   1/* SPDX-License-Identifier: GPL-2.0+ */
   2/*
   3 * alloc.h - persistent object (dat entry/disk inode) allocator/deallocator
   4 *
   5 * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
   6 *
   7 * Originally written by Koji Sato.
   8 * Two allocators were unified by Ryusuke Konishi and Amagai Yoshiji.
   9 */
  10
  11#ifndef _NILFS_ALLOC_H
  12#define _NILFS_ALLOC_H
  13
  14#include <linux/types.h>
  15#include <linux/buffer_head.h>
  16#include <linux/fs.h>
  17
  18/**
  19 * nilfs_palloc_entries_per_group - get the number of entries per group
  20 * @inode: inode of metadata file using this allocator
  21 *
  22 * The number of entries per group is defined by the number of bits
  23 * that a bitmap block can maintain.
  24 */
  25static inline unsigned long
  26nilfs_palloc_entries_per_group(const struct inode *inode)
  27{
  28        return 1UL << (inode->i_blkbits + 3 /* log2(8 = CHAR_BITS) */);
  29}
  30
  31int nilfs_palloc_init_blockgroup(struct inode *, unsigned int);
  32int nilfs_palloc_get_entry_block(struct inode *, __u64, int,
  33                                 struct buffer_head **);
  34void *nilfs_palloc_block_get_entry(const struct inode *, __u64,
  35                                   const struct buffer_head *, void *);
  36
  37int nilfs_palloc_count_max_entries(struct inode *, u64, u64 *);
  38
  39/**
  40 * nilfs_palloc_req - persistent allocator request and reply
  41 * @pr_entry_nr: entry number (vblocknr or inode number)
  42 * @pr_desc_bh: buffer head of the buffer containing block group descriptors
  43 * @pr_bitmap_bh: buffer head of the buffer containing a block group bitmap
  44 * @pr_entry_bh: buffer head of the buffer containing translation entries
  45 */
  46struct nilfs_palloc_req {
  47        __u64 pr_entry_nr;
  48        struct buffer_head *pr_desc_bh;
  49        struct buffer_head *pr_bitmap_bh;
  50        struct buffer_head *pr_entry_bh;
  51};
  52
  53int nilfs_palloc_prepare_alloc_entry(struct inode *,
  54                                     struct nilfs_palloc_req *);
  55void nilfs_palloc_commit_alloc_entry(struct inode *,
  56                                     struct nilfs_palloc_req *);
  57void nilfs_palloc_abort_alloc_entry(struct inode *, struct nilfs_palloc_req *);
  58void nilfs_palloc_commit_free_entry(struct inode *, struct nilfs_palloc_req *);
  59int nilfs_palloc_prepare_free_entry(struct inode *, struct nilfs_palloc_req *);
  60void nilfs_palloc_abort_free_entry(struct inode *, struct nilfs_palloc_req *);
  61int nilfs_palloc_freev(struct inode *, __u64 *, size_t);
  62
  63#define nilfs_set_bit_atomic            ext2_set_bit_atomic
  64#define nilfs_clear_bit_atomic          ext2_clear_bit_atomic
  65#define nilfs_find_next_zero_bit        find_next_zero_bit_le
  66#define nilfs_find_next_bit             find_next_bit_le
  67
  68/**
  69 * struct nilfs_bh_assoc - block offset and buffer head association
  70 * @blkoff: block offset
  71 * @bh: buffer head
  72 */
  73struct nilfs_bh_assoc {
  74        unsigned long blkoff;
  75        struct buffer_head *bh;
  76};
  77
  78/**
  79 * struct nilfs_palloc_cache - persistent object allocator cache
  80 * @lock: cache protecting lock
  81 * @prev_desc: blockgroup descriptors cache
  82 * @prev_bitmap: blockgroup bitmap cache
  83 * @prev_entry: translation entries cache
  84 */
  85struct nilfs_palloc_cache {
  86        spinlock_t lock;
  87        struct nilfs_bh_assoc prev_desc;
  88        struct nilfs_bh_assoc prev_bitmap;
  89        struct nilfs_bh_assoc prev_entry;
  90};
  91
  92void nilfs_palloc_setup_cache(struct inode *inode,
  93                              struct nilfs_palloc_cache *cache);
  94void nilfs_palloc_clear_cache(struct inode *inode);
  95void nilfs_palloc_destroy_cache(struct inode *inode);
  96
  97#endif  /* _NILFS_ALLOC_H */
  98