1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3 * 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 */
25 static inline unsigned long
26 nilfs_palloc_entries_per_group(const struct inode *inode)
27 {
28 return 1UL << (inode->i_blkbits + 3 /* log2(8 = CHAR_BITS) */);
29 }
30
31 int nilfs_palloc_init_blockgroup(struct inode *, unsigned int);
32 int nilfs_palloc_get_entry_block(struct inode *, __u64, int,
33 struct buffer_head **);
34 void *nilfs_palloc_block_get_entry(const struct inode *, __u64,
35 const struct buffer_head *, void *);
36
37 int 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 */
46 struct 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
53 int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
54 struct nilfs_palloc_req *req, bool wrap);
55 void nilfs_palloc_commit_alloc_entry(struct inode *,
56 struct nilfs_palloc_req *);
57 void nilfs_palloc_abort_alloc_entry(struct inode *, struct nilfs_palloc_req *);
58 void nilfs_palloc_commit_free_entry(struct inode *, struct nilfs_palloc_req *);
59 int nilfs_palloc_prepare_free_entry(struct inode *, struct nilfs_palloc_req *);
60 void nilfs_palloc_abort_free_entry(struct inode *, struct nilfs_palloc_req *);
61 int 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 */
73 struct 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 */
85 struct 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
92 void nilfs_palloc_setup_cache(struct inode *inode,
93 struct nilfs_palloc_cache *cache);
94 void nilfs_palloc_clear_cache(struct inode *inode);
95 void nilfs_palloc_destroy_cache(struct inode *inode);
96
97 #endif /* _NILFS_ALLOC_H */
98
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