1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3 * NILFS block mapping.
4 *
5 * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
6 *
7 * Written by Koji Sato.
8 */
9
10 #ifndef _NILFS_BMAP_H
11 #define _NILFS_BMAP_H
12
13 #include <linux/types.h>
14 #include <linux/fs.h>
15 #include <linux/buffer_head.h>
16 #include <linux/nilfs2_ondisk.h> /* nilfs_binfo, nilfs_inode, etc */
17 #include "alloc.h"
18 #include "dat.h"
19
20 #define NILFS_BMAP_INVALID_PTR 0
21
22 #define nilfs_bmap_keydiff_abs(diff) ((diff) < 0 ? -(diff) : (diff))
23
24
25 struct nilfs_bmap;
26
27 /**
28 * union nilfs_bmap_ptr_req - request for bmap ptr
29 * @bpr_ptr: bmap pointer
30 * @bpr_req: request for persistent allocator
31 */
32 union nilfs_bmap_ptr_req {
33 __u64 bpr_ptr;
34 struct nilfs_palloc_req bpr_req;
35 };
36
37 /**
38 * struct nilfs_bmap_stats - bmap statistics
39 * @bs_nblocks: number of blocks created or deleted
40 */
41 struct nilfs_bmap_stats {
42 unsigned int bs_nblocks;
43 };
44
45 /**
46 * struct nilfs_bmap_operations - bmap operation table
47 */
48 struct nilfs_bmap_operations {
49 int (*bop_lookup)(const struct nilfs_bmap *, __u64, int, __u64 *);
50 int (*bop_lookup_contig)(const struct nilfs_bmap *, __u64, __u64 *,
51 unsigned int);
52 int (*bop_insert)(struct nilfs_bmap *, __u64, __u64);
53 int (*bop_delete)(struct nilfs_bmap *, __u64);
54 void (*bop_clear)(struct nilfs_bmap *);
55
56 int (*bop_propagate)(struct nilfs_bmap *, struct buffer_head *);
57 void (*bop_lookup_dirty_buffers)(struct nilfs_bmap *,
58 struct list_head *);
59
60 int (*bop_assign)(struct nilfs_bmap *,
61 struct buffer_head **,
62 sector_t,
63 union nilfs_binfo *);
64 int (*bop_mark)(struct nilfs_bmap *, __u64, int);
65
66 int (*bop_seek_key)(const struct nilfs_bmap *, __u64, __u64 *);
67 int (*bop_last_key)(const struct nilfs_bmap *, __u64 *);
68
69 /* The following functions are internal use only. */
70 int (*bop_check_insert)(const struct nilfs_bmap *, __u64);
71 int (*bop_check_delete)(struct nilfs_bmap *, __u64);
72 int (*bop_gather_data)(struct nilfs_bmap *, __u64 *, __u64 *, int);
73 };
74
75
76 #define NILFS_BMAP_SIZE (NILFS_INODE_BMAP_SIZE * sizeof(__le64))
77 #define NILFS_BMAP_KEY_BIT (sizeof(unsigned long) * 8 /* CHAR_BIT */)
78 #define NILFS_BMAP_NEW_PTR_INIT \
79 (1UL << (sizeof(unsigned long) * 8 /* CHAR_BIT */ - 1))
80
81 static inline int nilfs_bmap_is_new_ptr(unsigned long ptr)
82 {
83 return !!(ptr & NILFS_BMAP_NEW_PTR_INIT);
84 }
85
86
87 /**
88 * struct nilfs_bmap - bmap structure
89 * @b_u: raw data
90 * @b_sem: semaphore
91 * @b_inode: owner of bmap
92 * @b_ops: bmap operation table
93 * @b_last_allocated_key: last allocated key for data block
94 * @b_last_allocated_ptr: last allocated ptr for data block
95 * @b_ptr_type: pointer type
96 * @b_state: state
97 * @b_nchildren_per_block: maximum number of child nodes for non-root nodes
98 */
99 struct nilfs_bmap {
100 union {
101 __u8 u_flags;
102 __le64 u_data[NILFS_BMAP_SIZE / sizeof(__le64)];
103 } b_u;
104 struct rw_semaphore b_sem;
105 struct inode *b_inode;
106 const struct nilfs_bmap_operations *b_ops;
107 __u64 b_last_allocated_key;
108 __u64 b_last_allocated_ptr;
109 int b_ptr_type;
110 int b_state;
111 __u16 b_nchildren_per_block;
112 };
113
114 /* pointer type */
115 #define NILFS_BMAP_PTR_P 0 /* physical block number (i.e. LBN) */
116 #define NILFS_BMAP_PTR_VS 1 /*
117 * virtual block number (single
118 * version)
119 */
120 #define NILFS_BMAP_PTR_VM 2 /*
121 * virtual block number (has multiple
122 * versions)
123 */
124 #define NILFS_BMAP_PTR_U (-1) /* never perform pointer operations */
125
126 #define NILFS_BMAP_USE_VBN(bmap) ((bmap)->b_ptr_type > 0)
127
128 /* state */
129 #define NILFS_BMAP_DIRTY 0x00000001
130
131 /**
132 * struct nilfs_bmap_store - shadow copy of bmap state
133 * @data: cached raw block mapping of on-disk inode
134 * @last_allocated_key: cached value of last allocated key for data block
135 * @last_allocated_ptr: cached value of last allocated ptr for data block
136 * @state: cached value of state field of bmap structure
137 */
138 struct nilfs_bmap_store {
139 __le64 data[NILFS_BMAP_SIZE / sizeof(__le64)];
140 __u64 last_allocated_key;
141 __u64 last_allocated_ptr;
142 int state;
143 };
144
145 int nilfs_bmap_test_and_clear_dirty(struct nilfs_bmap *);
146 int nilfs_bmap_read(struct nilfs_bmap *, struct nilfs_inode *);
147 void nilfs_bmap_write(struct nilfs_bmap *, struct nilfs_inode *);
148 int nilfs_bmap_lookup_contig(struct nilfs_bmap *, __u64, __u64 *, unsigned int);
149 int nilfs_bmap_insert(struct nilfs_bmap *bmap, __u64 key, unsigned long rec);
150 int nilfs_bmap_delete(struct nilfs_bmap *bmap, __u64 key);
151 int nilfs_bmap_seek_key(struct nilfs_bmap *bmap, __u64 start, __u64 *keyp);
152 int nilfs_bmap_last_key(struct nilfs_bmap *bmap, __u64 *keyp);
153 int nilfs_bmap_truncate(struct nilfs_bmap *bmap, __u64 key);
154 void nilfs_bmap_clear(struct nilfs_bmap *);
155 int nilfs_bmap_propagate(struct nilfs_bmap *, struct buffer_head *);
156 void nilfs_bmap_lookup_dirty_buffers(struct nilfs_bmap *, struct list_head *);
157 int nilfs_bmap_assign(struct nilfs_bmap *, struct buffer_head **,
158 unsigned long, union nilfs_binfo *);
159 int nilfs_bmap_lookup_at_level(struct nilfs_bmap *, __u64, int, __u64 *);
160 int nilfs_bmap_mark(struct nilfs_bmap *, __u64, int);
161
162 void nilfs_bmap_init_gc(struct nilfs_bmap *);
163
164 void nilfs_bmap_save(const struct nilfs_bmap *, struct nilfs_bmap_store *);
165 void nilfs_bmap_restore(struct nilfs_bmap *, const struct nilfs_bmap_store *);
166
167 static inline int nilfs_bmap_lookup(struct nilfs_bmap *bmap, __u64 key,
168 __u64 *ptr)
169 {
170 return nilfs_bmap_lookup_at_level(bmap, key, 1, ptr);
171 }
172
173 /*
174 * Internal use only
175 */
176 struct inode *nilfs_bmap_get_dat(const struct nilfs_bmap *);
177
178 static inline int nilfs_bmap_prepare_alloc_ptr(struct nilfs_bmap *bmap,
179 union nilfs_bmap_ptr_req *req,
180 struct inode *dat)
181 {
182 if (dat)
183 return nilfs_dat_prepare_alloc(dat, &req->bpr_req);
184 /* ignore target ptr */
185 req->bpr_ptr = bmap->b_last_allocated_ptr++;
186 return 0;
187 }
188
189 static inline void nilfs_bmap_commit_alloc_ptr(struct nilfs_bmap *bmap,
190 union nilfs_bmap_ptr_req *req,
191 struct inode *dat)
192 {
193 if (dat)
194 nilfs_dat_commit_alloc(dat, &req->bpr_req);
195 }
196
197 static inline void nilfs_bmap_abort_alloc_ptr(struct nilfs_bmap *bmap,
198 union nilfs_bmap_ptr_req *req,
199 struct inode *dat)
200 {
201 if (dat)
202 nilfs_dat_abort_alloc(dat, &req->bpr_req);
203 else
204 bmap->b_last_allocated_ptr--;
205 }
206
207 static inline int nilfs_bmap_prepare_end_ptr(struct nilfs_bmap *bmap,
208 union nilfs_bmap_ptr_req *req,
209 struct inode *dat)
210 {
211 return dat ? nilfs_dat_prepare_end(dat, &req->bpr_req) : 0;
212 }
213
214 static inline void nilfs_bmap_commit_end_ptr(struct nilfs_bmap *bmap,
215 union nilfs_bmap_ptr_req *req,
216 struct inode *dat)
217 {
218 if (dat)
219 nilfs_dat_commit_end(dat, &req->bpr_req,
220 bmap->b_ptr_type == NILFS_BMAP_PTR_VS);
221 }
222
223 static inline void nilfs_bmap_abort_end_ptr(struct nilfs_bmap *bmap,
224 union nilfs_bmap_ptr_req *req,
225 struct inode *dat)
226 {
227 if (dat)
228 nilfs_dat_abort_end(dat, &req->bpr_req);
229 }
230
231 static inline void nilfs_bmap_set_target_v(struct nilfs_bmap *bmap, __u64 key,
232 __u64 ptr)
233 {
234 bmap->b_last_allocated_key = key;
235 bmap->b_last_allocated_ptr = ptr;
236 }
237
238 __u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *,
239 const struct buffer_head *);
240
241 __u64 nilfs_bmap_find_target_seq(const struct nilfs_bmap *, __u64);
242 __u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *);
243
244
245 /* Assume that bmap semaphore is locked. */
246 static inline int nilfs_bmap_dirty(const struct nilfs_bmap *bmap)
247 {
248 return !!(bmap->b_state & NILFS_BMAP_DIRTY);
249 }
250
251 /* Assume that bmap semaphore is locked. */
252 static inline void nilfs_bmap_set_dirty(struct nilfs_bmap *bmap)
253 {
254 bmap->b_state |= NILFS_BMAP_DIRTY;
255 }
256
257 /* Assume that bmap semaphore is locked. */
258 static inline void nilfs_bmap_clear_dirty(struct nilfs_bmap *bmap)
259 {
260 bmap->b_state &= ~NILFS_BMAP_DIRTY;
261 }
262
263
264 #define NILFS_BMAP_LARGE 0x1
265
266 #define NILFS_BMAP_SMALL_LOW NILFS_DIRECT_KEY_MIN
267 #define NILFS_BMAP_SMALL_HIGH NILFS_DIRECT_KEY_MAX
268 #define NILFS_BMAP_LARGE_LOW NILFS_BTREE_ROOT_NCHILDREN_MAX
269 #define NILFS_BMAP_LARGE_HIGH NILFS_BTREE_KEY_MAX
270
271 #endif /* _NILFS_BMAP_H */
272
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.