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  */
  34 static inline unsigned long
  35 nilfs_palloc_entries_per_group(const struct inode *inode)
  36 {
  37         return 1UL << (inode->i_blkbits + 3 /* log2(8 = CHAR_BITS) */);
  38 }
  39
  40 int nilfs_palloc_init_blockgroup(struct inode *, unsigned int);
  41 int nilfs_palloc_get_entry_block(struct inode *, __u64, int,
  42                                  struct buffer_head **);
  43 void *nilfs_palloc_block_get_entry(const struct inode *, __u64,
  44                                    const struct buffer_head *, void *);
  45
  46 int 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  */
  55 struct 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
  62 int nilfs_palloc_prepare_alloc_entry(struct inode *,
  63                                      struct nilfs_palloc_req *);
  64 void nilfs_palloc_commit_alloc_entry(struct inode *,
  65                                      struct nilfs_palloc_req *);
  66 void nilfs_palloc_abort_alloc_entry(struct inode *, struct nilfs_palloc_req *);
  67 void nilfs_palloc_commit_free_entry(struct inode *, struct nilfs_palloc_req *);
  68 int nilfs_palloc_prepare_free_entry(struct inode *, struct nilfs_palloc_req *);
  69 void nilfs_palloc_abort_free_entry(struct inode *, struct nilfs_palloc_req *);
  70 int 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  */
  82 struct 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  */
  94 struct 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
 101 void nilfs_palloc_setup_cache(struct inode *inode,
 102                               struct nilfs_palloc_cache *cache);
 103 void nilfs_palloc_clear_cache(struct inode *inode);
 104 void nilfs_palloc_destroy_cache(struct inode *inode);
 105
 106 #endif  /* _NILFS_ALLOC_H */