aboutsummaryrefslogtreecommitdiff
path: root/fs/nilfs2/bmap.h
blob: bfa817ce40b3ad6f66faf296bf3b7e1033904435 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
/*
 * bmap.h - NILFS block mapping.
 *
 * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Written by Koji Sato <koji@osrg.net>.
 */

#ifndef _NILFS_BMAP_H
#define _NILFS_BMAP_H

#include <linux/types.h>
#include <linux/fs.h>
#include <linux/buffer_head.h>
#include <linux/nilfs2_fs.h>
#include "alloc.h"
#include "dat.h"

#define NILFS_BMAP_INVALID_PTR	0

#define nilfs_bmap_keydiff_abs(diff)	((diff) < 0 ? -(diff) : (diff))


struct nilfs_bmap;

/**
 * union nilfs_bmap_ptr_req - request for bmap ptr
 * @bpr_ptr: bmap pointer
 * @bpr_req: request for persistent allocator
 */
union nilfs_bmap_ptr_req {
	__u64 bpr_ptr;
	struct nilfs_palloc_req bpr_req;
};

/**
 * struct nilfs_bmap_stats - bmap statistics
 * @bs_nblocks: number of blocks created or deleted
 */
struct nilfs_bmap_stats {
	unsigned int bs_nblocks;
};

/**
 * struct nilfs_bmap_operations - bmap operation table
 */
struct nilfs_bmap_operations {
	int (*bop_lookup)(const struct nilfs_bmap *, __u64, int, __u64 *);
	int (*bop_lookup_contig)(const struct nilfs_bmap *, __u64, __u64 *,
				 unsigned);
	int (*bop_insert)(struct nilfs_bmap *, __u64, __u64);
	int (*bop_delete)(struct nilfs_bmap *, __u64);
	void (*bop_clear)(struct nilfs_bmap *);

	int (*bop_propagate)(struct nilfs_bmap *, struct buffer_head *);
	void (*bop_lookup_dirty_buffers)(struct nilfs_bmap *,
					 struct list_head *);

	int (*bop_assign)(struct nilfs_bmap *,
			  struct buffer_head **,
			  sector_t,
			  union nilfs_binfo *);
	int (*bop_mark)(struct nilfs_bmap *, __u64, int);

	int (*bop_seek_key)(const struct nilfs_bmap *, __u64, __u64 *);
	int (*bop_last_key)(const struct nilfs_bmap *, __u64 *);

	/* The following functions are internal use only. */
	int (*bop_check_insert)(const struct nilfs_bmap *, __u64);
	int (*bop_check_delete)(struct nilfs_bmap *, __u64);
	int (*bop_gather_data)(struct nilfs_bmap *, __u64 *, __u64 *, int);
};


#define NILFS_BMAP_SIZE		(NILFS_INODE_BMAP_SIZE * sizeof(__le64))
#define NILFS_BMAP_KEY_BIT	(sizeof(unsigned long) * 8 /* CHAR_BIT */)
#define NILFS_BMAP_NEW_PTR_INIT	\
	(1UL << (sizeof(unsigned long) * 8 /* CHAR_BIT */ - 1))

static inline int nilfs_bmap_is_new_ptr(unsigned long ptr)
{
	return !!(ptr & NILFS_BMAP_NEW_PTR_INIT);
}


/**
 * struct nilfs_bmap - bmap structure
 * @b_u: raw data
 * @b_sem: semaphore
 * @b_inode: owner of bmap
 * @b_ops: bmap operation table
 * @b_last_allocated_key: last allocated key for data block
 * @b_last_allocated_ptr: last allocated ptr for data block
 * @b_ptr_type: pointer type
 * @b_state: state
 * @b_nchildren_per_block: maximum number of child nodes for non-root nodes
 */
struct nilfs_bmap {
	union {
		__u8 u_flags;
		__le64 u_data[NILFS_BMAP_SIZE / sizeof(__le64)];
	} b_u;
	struct rw_semaphore b_sem;
	struct inode *b_inode;
	const struct nilfs_bmap_operations *b_ops;
	__u64 b_last_allocated_key;
	__u64 b_last_allocated_ptr;
	int b_ptr_type;
	int b_state;
	__u16 b_nchildren_per_block;
};

/* pointer type */
#define NILFS_BMAP_PTR_P	0	/* physical block number (i.e. LBN) */
#define NILFS_BMAP_PTR_VS	1	/* virtual block number (single
					   version) */
#define NILFS_BMAP_PTR_VM	2	/* virtual block number (has multiple
					   versions) */
#define NILFS_BMAP_PTR_U	(-1)	/* never perform pointer operations */

#define NILFS_BMAP_USE_VBN(bmap)	((bmap)->b_ptr_type > 0)

/* state */
#define NILFS_BMAP_DIRTY	0x00000001

/**
 * struct nilfs_bmap_store - shadow copy of bmap state
 * @data: cached raw block mapping of on-disk inode
 * @last_allocated_key: cached value of last allocated key for data block
 * @last_allocated_ptr: cached value of last allocated ptr for data block
 * @state: cached value of state field of bmap structure
 */
struct nilfs_bmap_store {
	__le64 data[NILFS_BMAP_SIZE / sizeof(__le64)];
	__u64 last_allocated_key;
	__u64 last_allocated_ptr;
	int state;
};

int nilfs_bmap_test_and_clear_dirty(struct nilfs_bmap *);
int nilfs_bmap_read(struct nilfs_bmap *, struct nilfs_inode *);
void nilfs_bmap_write(struct nilfs_bmap *, struct nilfs_inode *);
int nilfs_bmap_lookup_contig(struct nilfs_bmap *, __u64, __u64 *, unsigned);
int nilfs_bmap_insert(struct nilfs_bmap *bmap, __u64 key, unsigned long rec);
int nilfs_bmap_delete(struct nilfs_bmap *bmap, __u64 key);
int nilfs_bmap_seek_key(struct nilfs_bmap *bmap, __u64 start, __u64 *keyp);
int nilfs_bmap_last_key(struct nilfs_bmap *bmap, __u64 *keyp);
int nilfs_bmap_truncate(struct nilfs_bmap *bmap, __u64 key);
void nilfs_bmap_clear(struct nilfs_bmap *);
int nilfs_bmap_propagate(struct nilfs_bmap *, struct buffer_head *);
void nilfs_bmap_lookup_dirty_buffers(struct nilfs_bmap *, struct list_head *);
int nilfs_bmap_assign(struct nilfs_bmap *, struct buffer_head **,
		      unsigned long, union nilfs_binfo *);
int nilfs_bmap_lookup_at_level(struct nilfs_bmap *, __u64, int, __u64 *);
int nilfs_bmap_mark(struct nilfs_bmap *, __u64, int);

void nilfs_bmap_init_gc(struct nilfs_bmap *);

void nilfs_bmap_save(const struct nilfs_bmap *, struct nilfs_bmap_store *);
void nilfs_bmap_restore(struct nilfs_bmap *, const struct nilfs_bmap_store *);

static inline int nilfs_bmap_lookup(struct nilfs_bmap *bmap, __u64 key,
				    __u64 *ptr)
{
	return nilfs_bmap_lookup_at_level(bmap, key, 1, ptr);
}

/*
 * Internal use only
 */
struct inode *nilfs_bmap_get_dat(const struct nilfs_bmap *);

static inline int nilfs_bmap_prepare_alloc_ptr(struct nilfs_bmap *bmap,
					       union nilfs_bmap_ptr_req *req,
					       struct inode *dat)
{
	if (dat)
		return nilfs_dat_prepare_alloc(dat, &req->bpr_req);
	/* ignore target ptr */
	req->bpr_ptr = bmap->b_last_allocated_ptr++;
	return 0;
}

static inline void nilfs_bmap_commit_alloc_ptr(struct nilfs_bmap *bmap,
					       union nilfs_bmap_ptr_req *req,
					       struct inode *dat)
{
	if (dat)
		nilfs_dat_commit_alloc(dat, &req->bpr_req);
}

static inline void nilfs_bmap_abort_alloc_ptr(struct nilfs_bmap *bmap,
					      union nilfs_bmap_ptr_req *req,
					      struct inode *dat)
{
	if (dat)
		nilfs_dat_abort_alloc(dat, &req->bpr_req);
	else
		bmap->b_last_allocated_ptr--;
}

static inline int nilfs_bmap_prepare_end_ptr(struct nilfs_bmap *bmap,
					     union nilfs_bmap_ptr_req *req,
					     struct inode *dat)
{
	return dat ? nilfs_dat_prepare_end(dat, &req->bpr_req) : 0;
}

static inline void nilfs_bmap_commit_end_ptr(struct nilfs_bmap *bmap,
					     union nilfs_bmap_ptr_req *req,
					     struct inode *dat)
{
	if (dat)
		nilfs_dat_commit_end(dat, &req->bpr_req,
				     bmap->b_ptr_type == NILFS_BMAP_PTR_VS);
}

static inline void nilfs_bmap_abort_end_ptr(struct nilfs_bmap *bmap,
					    union nilfs_bmap_ptr_req *req,
					    struct inode *dat)
{
	if (dat)
		nilfs_dat_abort_end(dat, &req->bpr_req);
}

static inline void nilfs_bmap_set_target_v(struct nilfs_bmap *bmap, __u64 key,
					   __u64 ptr)
{
	bmap->b_last_allocated_key = key;
	bmap->b_last_allocated_ptr = ptr;
}

__u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *,
			      const struct buffer_head *);

__u64 nilfs_bmap_find_target_seq(const struct nilfs_bmap *, __u64);
__u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *);


/* Assume that bmap semaphore is locked. */
static inline int nilfs_bmap_dirty(const struct nilfs_bmap *bmap)
{
	return !!(bmap->b_state & NILFS_BMAP_DIRTY);
}

/* Assume that bmap semaphore is locked. */
static inline void nilfs_bmap_set_dirty(struct nilfs_bmap *bmap)
{
	bmap->b_state |= NILFS_BMAP_DIRTY;
}

/* Assume that bmap semaphore is locked. */
static inline void nilfs_bmap_clear_dirty(struct nilfs_bmap *bmap)
{
	bmap->b_state &= ~NILFS_BMAP_DIRTY;
}


#define NILFS_BMAP_LARGE	0x1

#define NILFS_BMAP_SMALL_LOW	NILFS_DIRECT_KEY_MIN
#define NILFS_BMAP_SMALL_HIGH	NILFS_DIRECT_KEY_MAX
#define NILFS_BMAP_LARGE_LOW	NILFS_BTREE_ROOT_NCHILDREN_MAX
#define NILFS_BMAP_LARGE_HIGH	NILFS_BTREE_KEY_MAX

#endif	/* _NILFS_BMAP_H */