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 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 *
20 * Original code was written by Koji Sato <koji@osrg.net>.
21 * Two allocators were unified by Ryusuke Konishi <ryusuke@osrg.net>,
22 * Amagai Yoshiji <amagai@osrg.net>.
23 */
24
25 #ifndef _NILFS_ALLOC_H
26 #define _NILFS_ALLOC_H
27
28 #include <linux/types.h>
29 #include <linux/buffer_head.h>
30 #include <linux/fs.h>
31
32 /**
33 * nilfs_palloc_entries_per_group - get the number of entries per group
34 * @inode: inode of metadata file using this allocator
35 *
36 * The number of entries per group is defined by the number of bits
37 * that a bitmap block can maintain.
38 */
39 static inline unsigned long
nilfs_palloc_entries_per_group(const struct inode * inode)40 nilfs_palloc_entries_per_group(const struct inode *inode)
41 {
42 return 1UL << (inode->i_blkbits + 3 /* log2(8 = CHAR_BITS) */);
43 }
44
45 int nilfs_palloc_init_blockgroup(struct inode *, unsigned);
46 int nilfs_palloc_get_entry_block(struct inode *, __u64, int,
47 struct buffer_head **);
48 void *nilfs_palloc_block_get_entry(const struct inode *, __u64,
49 const struct buffer_head *, void *);
50
51 int nilfs_palloc_count_max_entries(struct inode *, u64, u64 *);
52
53 /**
54 * nilfs_palloc_req - persistent allocator request and reply
55 * @pr_entry_nr: entry number (vblocknr or inode number)
56 * @pr_desc_bh: buffer head of the buffer containing block group descriptors
57 * @pr_bitmap_bh: buffer head of the buffer containing a block group bitmap
58 * @pr_entry_bh: buffer head of the buffer containing translation entries
59 */
60 struct nilfs_palloc_req {
61 __u64 pr_entry_nr;
62 struct buffer_head *pr_desc_bh;
63 struct buffer_head *pr_bitmap_bh;
64 struct buffer_head *pr_entry_bh;
65 };
66
67 int nilfs_palloc_prepare_alloc_entry(struct inode *,
68 struct nilfs_palloc_req *);
69 void nilfs_palloc_commit_alloc_entry(struct inode *,
70 struct nilfs_palloc_req *);
71 void nilfs_palloc_abort_alloc_entry(struct inode *, struct nilfs_palloc_req *);
72 void nilfs_palloc_commit_free_entry(struct inode *, struct nilfs_palloc_req *);
73 int nilfs_palloc_prepare_free_entry(struct inode *, struct nilfs_palloc_req *);
74 void nilfs_palloc_abort_free_entry(struct inode *, struct nilfs_palloc_req *);
75 int nilfs_palloc_freev(struct inode *, __u64 *, size_t);
76
77 #define nilfs_set_bit_atomic ext2_set_bit_atomic
78 #define nilfs_clear_bit_atomic ext2_clear_bit_atomic
79 #define nilfs_find_next_zero_bit find_next_zero_bit_le
80 #define nilfs_find_next_bit find_next_bit_le
81
82 /**
83 * struct nilfs_bh_assoc - block offset and buffer head association
84 * @blkoff: block offset
85 * @bh: buffer head
86 */
87 struct nilfs_bh_assoc {
88 unsigned long blkoff;
89 struct buffer_head *bh;
90 };
91
92 /**
93 * struct nilfs_palloc_cache - persistent object allocator cache
94 * @lock: cache protecting lock
95 * @prev_desc: blockgroup descriptors cache
96 * @prev_bitmap: blockgroup bitmap cache
97 * @prev_entry: translation entries cache
98 */
99 struct nilfs_palloc_cache {
100 spinlock_t lock;
101 struct nilfs_bh_assoc prev_desc;
102 struct nilfs_bh_assoc prev_bitmap;
103 struct nilfs_bh_assoc prev_entry;
104 };
105
106 void nilfs_palloc_setup_cache(struct inode *inode,
107 struct nilfs_palloc_cache *cache);
108 void nilfs_palloc_clear_cache(struct inode *inode);
109 void nilfs_palloc_destroy_cache(struct inode *inode);
110
111 #endif /* _NILFS_ALLOC_H */
112