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 /**
52 * nilfs_palloc_req - persistent allocator request and reply
53 * @pr_entry_nr: entry number (vblocknr or inode number)
54 * @pr_desc_bh: buffer head of the buffer containing block group descriptors
55 * @pr_bitmap_bh: buffer head of the buffer containing a block group bitmap
56 * @pr_entry_bh: buffer head of the buffer containing translation entries
57 */
58 struct nilfs_palloc_req {
59 __u64 pr_entry_nr;
60 struct buffer_head *pr_desc_bh;
61 struct buffer_head *pr_bitmap_bh;
62 struct buffer_head *pr_entry_bh;
63 };
64
65 int nilfs_palloc_prepare_alloc_entry(struct inode *,
66 struct nilfs_palloc_req *);
67 void nilfs_palloc_commit_alloc_entry(struct inode *,
68 struct nilfs_palloc_req *);
69 void nilfs_palloc_abort_alloc_entry(struct inode *, struct nilfs_palloc_req *);
70 void nilfs_palloc_commit_free_entry(struct inode *, struct nilfs_palloc_req *);
71 int nilfs_palloc_prepare_free_entry(struct inode *, struct nilfs_palloc_req *);
72 void nilfs_palloc_abort_free_entry(struct inode *, struct nilfs_palloc_req *);
73 int nilfs_palloc_freev(struct inode *, __u64 *, size_t);
74
75 #define nilfs_set_bit_atomic ext2_set_bit_atomic
76 #define nilfs_clear_bit_atomic ext2_clear_bit_atomic
77 #define nilfs_find_next_zero_bit find_next_zero_bit_le
78
79 /*
80 * persistent object allocator cache
81 */
82
83 struct nilfs_bh_assoc {
84 unsigned long blkoff;
85 struct buffer_head *bh;
86 };
87
88 struct nilfs_palloc_cache {
89 spinlock_t lock;
90 struct nilfs_bh_assoc prev_desc;
91 struct nilfs_bh_assoc prev_bitmap;
92 struct nilfs_bh_assoc prev_entry;
93 };
94
95 void nilfs_palloc_setup_cache(struct inode *inode,
96 struct nilfs_palloc_cache *cache);
97 void nilfs_palloc_clear_cache(struct inode *inode);
98 void nilfs_palloc_destroy_cache(struct inode *inode);
99
100 #endif /* _NILFS_ALLOC_H */
101