LXR linux/fs/nilfs2/alloc.h

   1/*
   2 * alloc.h - persistent object (dat entry/disk inode) allocator/deallocator
   3 *
   4 * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation; either version 2 of the License, or
   9 * (at your option) any later version.
  10 *
  11 * This program is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 * GNU General Public License for more details.
  15 *
  16 * Originally written by Koji Sato.
  17 * Two allocators were unified by Ryusuke Konishi and Amagai Yoshiji.
  18 */
  19
  20#ifndef _NILFS_ALLOC_H
  21#define _NILFS_ALLOC_H
  22
  23#include <linux/types.h>
  24#include <linux/buffer_head.h>
  25#include <linux/fs.h>
  26
  27/**
  28 * nilfs_palloc_entries_per_group - get the number of entries per group
  29 * @inode: inode of metadata file using this allocator
  30 *
  31 * The number of entries per group is defined by the number of bits
  32 * that a bitmap block can maintain.
  33 */
  34static inline unsigned long
  35nilfs_palloc_entries_per_group(const struct inode *inode)
  36{
  37        return 1UL << (inode->i_blkbits + 3 /* log2(8 = CHAR_BITS) */);
  38}
  39
  40int nilfs_palloc_init_blockgroup(struct inode *, unsigned int);
  41int nilfs_palloc_get_entry_block(struct inode *, __u64, int,
  42                                 struct buffer_head **);
  43void *nilfs_palloc_block_get_entry(const struct inode *, __u64,
  44                                   const struct buffer_head *, void *);
  45
  46int nilfs_palloc_count_max_entries(struct inode *, u64, u64 *);
  47
  48/**
  49 * nilfs_palloc_req - persistent allocator request and reply
  50 * @pr_entry_nr: entry number (vblocknr or inode number)
  51 * @pr_desc_bh: buffer head of the buffer containing block group descriptors
  52 * @pr_bitmap_bh: buffer head of the buffer containing a block group bitmap
  53 * @pr_entry_bh: buffer head of the buffer containing translation entries
  54 */
  55struct nilfs_palloc_req {
  56        __u64 pr_entry_nr;
  57        struct buffer_head *pr_desc_bh;
  58        struct buffer_head *pr_bitmap_bh;
  59        struct buffer_head *pr_entry_bh;
  60};
  61
  62int nilfs_palloc_prepare_alloc_entry(struct inode *,
  63                                     struct nilfs_palloc_req *);
  64void nilfs_palloc_commit_alloc_entry(struct inode *,
  65                                     struct nilfs_palloc_req *);
  66void nilfs_palloc_abort_alloc_entry(struct inode *, struct nilfs_palloc_req *);
  67void nilfs_palloc_commit_free_entry(struct inode *, struct nilfs_palloc_req *);
  68int nilfs_palloc_prepare_free_entry(struct inode *, struct nilfs_palloc_req *);
  69void nilfs_palloc_abort_free_entry(struct inode *, struct nilfs_palloc_req *);
  70int nilfs_palloc_freev(struct inode *, __u64 *, size_t);
  71
  72#define nilfs_set_bit_atomic            ext2_set_bit_atomic
  73#define nilfs_clear_bit_atomic          ext2_clear_bit_atomic
  74#define nilfs_find_next_zero_bit        find_next_zero_bit_le
  75#define nilfs_find_next_bit             find_next_bit_le
  76
  77/**
  78 * struct nilfs_bh_assoc - block offset and buffer head association
  79 * @blkoff: block offset
  80 * @bh: buffer head
  81 */
  82struct nilfs_bh_assoc {
  83        unsigned long blkoff;
  84        struct buffer_head *bh;
  85};
  86
  87/**
  88 * struct nilfs_palloc_cache - persistent object allocator cache
  89 * @lock: cache protecting lock
  90 * @prev_desc: blockgroup descriptors cache
  91 * @prev_bitmap: blockgroup bitmap cache
  92 * @prev_entry: translation entries cache
  93 */
  94struct nilfs_palloc_cache {
  95        spinlock_t lock;
  96        struct nilfs_bh_assoc prev_desc;
  97        struct nilfs_bh_assoc prev_bitmap;
  98        struct nilfs_bh_assoc prev_entry;
  99};
 100
 101void nilfs_palloc_setup_cache(struct inode *inode,
 102                              struct nilfs_palloc_cache *cache);
 103void nilfs_palloc_clear_cache(struct inode *inode);
 104void nilfs_palloc_destroy_cache(struct inode *inode);
 105
 106#endif  /* _NILFS_ALLOC_H */
 107