1 /*
2 * bmap.h - NILFS block mapping.
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 * Written by Koji Sato <koji@osrg.net>.
21 */
22
23 #ifndef _NILFS_BMAP_H
24 #define _NILFS_BMAP_H
25
26 #include <linux/types.h>
27 #include <linux/fs.h>
28 #include <linux/buffer_head.h>
29 #include <linux/nilfs2_fs.h>
30 #include "alloc.h"
31 #include "dat.h"
32
33 #define NILFS_BMAP_INVALID_PTR 0
34
35 #define nilfs_bmap_keydiff_abs(diff) ((diff) < 0 ? -(diff) : (diff))
36
37
38 struct nilfs_bmap;
39
40 /**
41 * union nilfs_bmap_ptr_req - request for bmap ptr
42 * @bpr_ptr: bmap pointer
43 * @bpr_req: request for persistent allocator
44 */
45 union nilfs_bmap_ptr_req {
46 __u64 bpr_ptr;
47 struct nilfs_palloc_req bpr_req;
48 };
49
50 /**
51 * struct nilfs_bmap_stats - bmap statistics
52 * @bs_nblocks: number of blocks created or deleted
53 */
54 struct nilfs_bmap_stats {
55 unsigned int bs_nblocks;
56 };
57
58 /**
59 * struct nilfs_bmap_operations - bmap operation table
60 */
61 struct nilfs_bmap_operations {
62 int (*bop_lookup)(const struct nilfs_bmap *, __u64, int, __u64 *);
63 int (*bop_lookup_contig)(const struct nilfs_bmap *, __u64, __u64 *,
64 unsigned);
65 int (*bop_insert)(struct nilfs_bmap *, __u64, __u64);
66 int (*bop_delete)(struct nilfs_bmap *, __u64);
67 void (*bop_clear)(struct nilfs_bmap *);
68
69 int (*bop_propagate)(struct nilfs_bmap *, struct buffer_head *);
70 void (*bop_lookup_dirty_buffers)(struct nilfs_bmap *,
71 struct list_head *);
72
73 int (*bop_assign)(struct nilfs_bmap *,
74 struct buffer_head **,
75 sector_t,
76 union nilfs_binfo *);
77 int (*bop_mark)(struct nilfs_bmap *, __u64, int);
78
79 int (*bop_seek_key)(const struct nilfs_bmap *, __u64, __u64 *);
80 int (*bop_last_key)(const struct nilfs_bmap *, __u64 *);
81
82 /* The following functions are internal use only. */
83 int (*bop_check_insert)(const struct nilfs_bmap *, __u64);
84 int (*bop_check_delete)(struct nilfs_bmap *, __u64);
85 int (*bop_gather_data)(struct nilfs_bmap *, __u64 *, __u64 *, int);
86 };
87
88
89 #define NILFS_BMAP_SIZE (NILFS_INODE_BMAP_SIZE * sizeof(__le64))
90 #define NILFS_BMAP_KEY_BIT (sizeof(unsigned long) * 8 /* CHAR_BIT */)
91 #define NILFS_BMAP_NEW_PTR_INIT \
92 (1UL << (sizeof(unsigned long) * 8 /* CHAR_BIT */ - 1))
93
nilfs_bmap_is_new_ptr(unsigned long ptr)94 static inline int nilfs_bmap_is_new_ptr(unsigned long ptr)
95 {
96 return !!(ptr & NILFS_BMAP_NEW_PTR_INIT);
97 }
98
99
100 /**
101 * struct nilfs_bmap - bmap structure
102 * @b_u: raw data
103 * @b_sem: semaphore
104 * @b_inode: owner of bmap
105 * @b_ops: bmap operation table
106 * @b_last_allocated_key: last allocated key for data block
107 * @b_last_allocated_ptr: last allocated ptr for data block
108 * @b_ptr_type: pointer type
109 * @b_state: state
110 * @b_nchildren_per_block: maximum number of child nodes for non-root nodes
111 */
112 struct nilfs_bmap {
113 union {
114 __u8 u_flags;
115 __le64 u_data[NILFS_BMAP_SIZE / sizeof(__le64)];
116 } b_u;
117 struct rw_semaphore b_sem;
118 struct inode *b_inode;
119 const struct nilfs_bmap_operations *b_ops;
120 __u64 b_last_allocated_key;
121 __u64 b_last_allocated_ptr;
122 int b_ptr_type;
123 int b_state;
124 __u16 b_nchildren_per_block;
125 };
126
127 /* pointer type */
128 #define NILFS_BMAP_PTR_P 0 /* physical block number (i.e. LBN) */
129 #define NILFS_BMAP_PTR_VS 1 /* virtual block number (single
130 version) */
131 #define NILFS_BMAP_PTR_VM 2 /* virtual block number (has multiple
132 versions) */
133 #define NILFS_BMAP_PTR_U (-1) /* never perform pointer operations */
134
135 #define NILFS_BMAP_USE_VBN(bmap) ((bmap)->b_ptr_type > 0)
136
137 /* state */
138 #define NILFS_BMAP_DIRTY 0x00000001
139
140 /**
141 * struct nilfs_bmap_store - shadow copy of bmap state
142 * @data: cached raw block mapping of on-disk inode
143 * @last_allocated_key: cached value of last allocated key for data block
144 * @last_allocated_ptr: cached value of last allocated ptr for data block
145 * @state: cached value of state field of bmap structure
146 */
147 struct nilfs_bmap_store {
148 __le64 data[NILFS_BMAP_SIZE / sizeof(__le64)];
149 __u64 last_allocated_key;
150 __u64 last_allocated_ptr;
151 int state;
152 };
153
154 int nilfs_bmap_test_and_clear_dirty(struct nilfs_bmap *);
155 int nilfs_bmap_read(struct nilfs_bmap *, struct nilfs_inode *);
156 void nilfs_bmap_write(struct nilfs_bmap *, struct nilfs_inode *);
157 int nilfs_bmap_lookup_contig(struct nilfs_bmap *, __u64, __u64 *, unsigned);
158 int nilfs_bmap_insert(struct nilfs_bmap *bmap, __u64 key, unsigned long rec);
159 int nilfs_bmap_delete(struct nilfs_bmap *bmap, __u64 key);
160 int nilfs_bmap_seek_key(struct nilfs_bmap *bmap, __u64 start, __u64 *keyp);
161 int nilfs_bmap_last_key(struct nilfs_bmap *bmap, __u64 *keyp);
162 int nilfs_bmap_truncate(struct nilfs_bmap *bmap, __u64 key);
163 void nilfs_bmap_clear(struct nilfs_bmap *);
164 int nilfs_bmap_propagate(struct nilfs_bmap *, struct buffer_head *);
165 void nilfs_bmap_lookup_dirty_buffers(struct nilfs_bmap *, struct list_head *);
166 int nilfs_bmap_assign(struct nilfs_bmap *, struct buffer_head **,
167 unsigned long, union nilfs_binfo *);
168 int nilfs_bmap_lookup_at_level(struct nilfs_bmap *, __u64, int, __u64 *);
169 int nilfs_bmap_mark(struct nilfs_bmap *, __u64, int);
170
171 void nilfs_bmap_init_gc(struct nilfs_bmap *);
172
173 void nilfs_bmap_save(const struct nilfs_bmap *, struct nilfs_bmap_store *);
174 void nilfs_bmap_restore(struct nilfs_bmap *, const struct nilfs_bmap_store *);
175
nilfs_bmap_lookup(struct nilfs_bmap * bmap,__u64 key,__u64 * ptr)176 static inline int nilfs_bmap_lookup(struct nilfs_bmap *bmap, __u64 key,
177 __u64 *ptr)
178 {
179 return nilfs_bmap_lookup_at_level(bmap, key, 1, ptr);
180 }
181
182 /*
183 * Internal use only
184 */
185 struct inode *nilfs_bmap_get_dat(const struct nilfs_bmap *);
186
nilfs_bmap_prepare_alloc_ptr(struct nilfs_bmap * bmap,union nilfs_bmap_ptr_req * req,struct inode * dat)187 static inline int nilfs_bmap_prepare_alloc_ptr(struct nilfs_bmap *bmap,
188 union nilfs_bmap_ptr_req *req,
189 struct inode *dat)
190 {
191 if (dat)
192 return nilfs_dat_prepare_alloc(dat, &req->bpr_req);
193 /* ignore target ptr */
194 req->bpr_ptr = bmap->b_last_allocated_ptr++;
195 return 0;
196 }
197
nilfs_bmap_commit_alloc_ptr(struct nilfs_bmap * bmap,union nilfs_bmap_ptr_req * req,struct inode * dat)198 static inline void nilfs_bmap_commit_alloc_ptr(struct nilfs_bmap *bmap,
199 union nilfs_bmap_ptr_req *req,
200 struct inode *dat)
201 {
202 if (dat)
203 nilfs_dat_commit_alloc(dat, &req->bpr_req);
204 }
205
nilfs_bmap_abort_alloc_ptr(struct nilfs_bmap * bmap,union nilfs_bmap_ptr_req * req,struct inode * dat)206 static inline void nilfs_bmap_abort_alloc_ptr(struct nilfs_bmap *bmap,
207 union nilfs_bmap_ptr_req *req,
208 struct inode *dat)
209 {
210 if (dat)
211 nilfs_dat_abort_alloc(dat, &req->bpr_req);
212 else
213 bmap->b_last_allocated_ptr--;
214 }
215
nilfs_bmap_prepare_end_ptr(struct nilfs_bmap * bmap,union nilfs_bmap_ptr_req * req,struct inode * dat)216 static inline int nilfs_bmap_prepare_end_ptr(struct nilfs_bmap *bmap,
217 union nilfs_bmap_ptr_req *req,
218 struct inode *dat)
219 {
220 return dat ? nilfs_dat_prepare_end(dat, &req->bpr_req) : 0;
221 }
222
nilfs_bmap_commit_end_ptr(struct nilfs_bmap * bmap,union nilfs_bmap_ptr_req * req,struct inode * dat)223 static inline void nilfs_bmap_commit_end_ptr(struct nilfs_bmap *bmap,
224 union nilfs_bmap_ptr_req *req,
225 struct inode *dat)
226 {
227 if (dat)
228 nilfs_dat_commit_end(dat, &req->bpr_req,
229 bmap->b_ptr_type == NILFS_BMAP_PTR_VS);
230 }
231
nilfs_bmap_abort_end_ptr(struct nilfs_bmap * bmap,union nilfs_bmap_ptr_req * req,struct inode * dat)232 static inline void nilfs_bmap_abort_end_ptr(struct nilfs_bmap *bmap,
233 union nilfs_bmap_ptr_req *req,
234 struct inode *dat)
235 {
236 if (dat)
237 nilfs_dat_abort_end(dat, &req->bpr_req);
238 }
239
nilfs_bmap_set_target_v(struct nilfs_bmap * bmap,__u64 key,__u64 ptr)240 static inline void nilfs_bmap_set_target_v(struct nilfs_bmap *bmap, __u64 key,
241 __u64 ptr)
242 {
243 bmap->b_last_allocated_key = key;
244 bmap->b_last_allocated_ptr = ptr;
245 }
246
247 __u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *,
248 const struct buffer_head *);
249
250 __u64 nilfs_bmap_find_target_seq(const struct nilfs_bmap *, __u64);
251 __u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *);
252
253
254 /* Assume that bmap semaphore is locked. */
nilfs_bmap_dirty(const struct nilfs_bmap * bmap)255 static inline int nilfs_bmap_dirty(const struct nilfs_bmap *bmap)
256 {
257 return !!(bmap->b_state & NILFS_BMAP_DIRTY);
258 }
259
260 /* Assume that bmap semaphore is locked. */
nilfs_bmap_set_dirty(struct nilfs_bmap * bmap)261 static inline void nilfs_bmap_set_dirty(struct nilfs_bmap *bmap)
262 {
263 bmap->b_state |= NILFS_BMAP_DIRTY;
264 }
265
266 /* Assume that bmap semaphore is locked. */
nilfs_bmap_clear_dirty(struct nilfs_bmap * bmap)267 static inline void nilfs_bmap_clear_dirty(struct nilfs_bmap *bmap)
268 {
269 bmap->b_state &= ~NILFS_BMAP_DIRTY;
270 }
271
272
273 #define NILFS_BMAP_LARGE 0x1
274
275 #define NILFS_BMAP_SMALL_LOW NILFS_DIRECT_KEY_MIN
276 #define NILFS_BMAP_SMALL_HIGH NILFS_DIRECT_KEY_MAX
277 #define NILFS_BMAP_LARGE_LOW NILFS_BTREE_ROOT_NCHILDREN_MAX
278 #define NILFS_BMAP_LARGE_HIGH NILFS_BTREE_KEY_MAX
279
280 #endif /* _NILFS_BMAP_H */
281