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 /* The following functions are internal use only. */
80 int (*bop_last_key)(const struct nilfs_bmap *, __u64 *);
81 int (*bop_check_insert)(const struct nilfs_bmap *, __u64);
82 int (*bop_check_delete)(struct nilfs_bmap *, __u64);
83 int (*bop_gather_data)(struct nilfs_bmap *, __u64 *, __u64 *, int);
84 };
85
86
87 #define NILFS_BMAP_SIZE (NILFS_INODE_BMAP_SIZE * sizeof(__le64))
88 #define NILFS_BMAP_KEY_BIT (sizeof(unsigned long) * 8 /* CHAR_BIT */)
89 #define NILFS_BMAP_NEW_PTR_INIT \
90 (1UL << (sizeof(unsigned long) * 8 /* CHAR_BIT */ - 1))
91
nilfs_bmap_is_new_ptr(unsigned long ptr)92 static inline int nilfs_bmap_is_new_ptr(unsigned long ptr)
93 {
94 return !!(ptr & NILFS_BMAP_NEW_PTR_INIT);
95 }
96
97
98 /**
99 * struct nilfs_bmap - bmap structure
100 * @b_u: raw data
101 * @b_sem: semaphore
102 * @b_inode: owner of bmap
103 * @b_ops: bmap operation table
104 * @b_last_allocated_key: last allocated key for data block
105 * @b_last_allocated_ptr: last allocated ptr for data block
106 * @b_ptr_type: pointer type
107 * @b_state: state
108 * @b_nchildren_per_block: maximum number of child nodes for non-root nodes
109 */
110 struct nilfs_bmap {
111 union {
112 __u8 u_flags;
113 __le64 u_data[NILFS_BMAP_SIZE / sizeof(__le64)];
114 } b_u;
115 struct rw_semaphore b_sem;
116 struct inode *b_inode;
117 const struct nilfs_bmap_operations *b_ops;
118 __u64 b_last_allocated_key;
119 __u64 b_last_allocated_ptr;
120 int b_ptr_type;
121 int b_state;
122 __u16 b_nchildren_per_block;
123 };
124
125 /* pointer type */
126 #define NILFS_BMAP_PTR_P 0 /* physical block number (i.e. LBN) */
127 #define NILFS_BMAP_PTR_VS 1 /* virtual block number (single
128 version) */
129 #define NILFS_BMAP_PTR_VM 2 /* virtual block number (has multiple
130 versions) */
131 #define NILFS_BMAP_PTR_U (-1) /* never perform pointer operations */
132
133 #define NILFS_BMAP_USE_VBN(bmap) ((bmap)->b_ptr_type > 0)
134
135 /* state */
136 #define NILFS_BMAP_DIRTY 0x00000001
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);
149 int nilfs_bmap_insert(struct nilfs_bmap *, unsigned long, unsigned long);
150 int nilfs_bmap_delete(struct nilfs_bmap *, unsigned long);
151 int nilfs_bmap_last_key(struct nilfs_bmap *, unsigned long *);
152 int nilfs_bmap_truncate(struct nilfs_bmap *, unsigned long);
153 void nilfs_bmap_clear(struct nilfs_bmap *);
154 int nilfs_bmap_propagate(struct nilfs_bmap *, struct buffer_head *);
155 void nilfs_bmap_lookup_dirty_buffers(struct nilfs_bmap *, struct list_head *);
156 int nilfs_bmap_assign(struct nilfs_bmap *, struct buffer_head **,
157 unsigned long, union nilfs_binfo *);
158 int nilfs_bmap_lookup_at_level(struct nilfs_bmap *, __u64, int, __u64 *);
159 int nilfs_bmap_mark(struct nilfs_bmap *, __u64, int);
160
161 void nilfs_bmap_init_gc(struct nilfs_bmap *);
162
163 void nilfs_bmap_save(const struct nilfs_bmap *, struct nilfs_bmap_store *);
164 void nilfs_bmap_restore(struct nilfs_bmap *, const struct nilfs_bmap_store *);
165
nilfs_bmap_lookup(struct nilfs_bmap * bmap,__u64 key,__u64 * ptr)166 static inline int nilfs_bmap_lookup(struct nilfs_bmap *bmap, __u64 key,
167 __u64 *ptr)
168 {
169 return nilfs_bmap_lookup_at_level(bmap, key, 1, ptr);
170 }
171
172 /*
173 * Internal use only
174 */
175 struct inode *nilfs_bmap_get_dat(const struct nilfs_bmap *);
176
nilfs_bmap_prepare_alloc_ptr(struct nilfs_bmap * bmap,union nilfs_bmap_ptr_req * req,struct inode * dat)177 static inline int nilfs_bmap_prepare_alloc_ptr(struct nilfs_bmap *bmap,
178 union nilfs_bmap_ptr_req *req,
179 struct inode *dat)
180 {
181 if (dat)
182 return nilfs_dat_prepare_alloc(dat, &req->bpr_req);
183 /* ignore target ptr */
184 req->bpr_ptr = bmap->b_last_allocated_ptr++;
185 return 0;
186 }
187
nilfs_bmap_commit_alloc_ptr(struct nilfs_bmap * bmap,union nilfs_bmap_ptr_req * req,struct inode * dat)188 static inline void nilfs_bmap_commit_alloc_ptr(struct nilfs_bmap *bmap,
189 union nilfs_bmap_ptr_req *req,
190 struct inode *dat)
191 {
192 if (dat)
193 nilfs_dat_commit_alloc(dat, &req->bpr_req);
194 }
195
nilfs_bmap_abort_alloc_ptr(struct nilfs_bmap * bmap,union nilfs_bmap_ptr_req * req,struct inode * dat)196 static inline void nilfs_bmap_abort_alloc_ptr(struct nilfs_bmap *bmap,
197 union nilfs_bmap_ptr_req *req,
198 struct inode *dat)
199 {
200 if (dat)
201 nilfs_dat_abort_alloc(dat, &req->bpr_req);
202 else
203 bmap->b_last_allocated_ptr--;
204 }
205
nilfs_bmap_prepare_end_ptr(struct nilfs_bmap * bmap,union nilfs_bmap_ptr_req * req,struct inode * dat)206 static inline int nilfs_bmap_prepare_end_ptr(struct nilfs_bmap *bmap,
207 union nilfs_bmap_ptr_req *req,
208 struct inode *dat)
209 {
210 return dat ? nilfs_dat_prepare_end(dat, &req->bpr_req) : 0;
211 }
212
nilfs_bmap_commit_end_ptr(struct nilfs_bmap * bmap,union nilfs_bmap_ptr_req * req,struct inode * dat)213 static inline void nilfs_bmap_commit_end_ptr(struct nilfs_bmap *bmap,
214 union nilfs_bmap_ptr_req *req,
215 struct inode *dat)
216 {
217 if (dat)
218 nilfs_dat_commit_end(dat, &req->bpr_req,
219 bmap->b_ptr_type == NILFS_BMAP_PTR_VS);
220 }
221
nilfs_bmap_abort_end_ptr(struct nilfs_bmap * bmap,union nilfs_bmap_ptr_req * req,struct inode * dat)222 static inline void nilfs_bmap_abort_end_ptr(struct nilfs_bmap *bmap,
223 union nilfs_bmap_ptr_req *req,
224 struct inode *dat)
225 {
226 if (dat)
227 nilfs_dat_abort_end(dat, &req->bpr_req);
228 }
229
nilfs_bmap_set_target_v(struct nilfs_bmap * bmap,__u64 key,__u64 ptr)230 static inline void nilfs_bmap_set_target_v(struct nilfs_bmap *bmap, __u64 key,
231 __u64 ptr)
232 {
233 bmap->b_last_allocated_key = key;
234 bmap->b_last_allocated_ptr = ptr;
235 }
236
237 __u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *,
238 const struct buffer_head *);
239
240 __u64 nilfs_bmap_find_target_seq(const struct nilfs_bmap *, __u64);
241 __u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *);
242
243
244 /* Assume that bmap semaphore is locked. */
nilfs_bmap_dirty(const struct nilfs_bmap * bmap)245 static inline int nilfs_bmap_dirty(const struct nilfs_bmap *bmap)
246 {
247 return !!(bmap->b_state & NILFS_BMAP_DIRTY);
248 }
249
250 /* Assume that bmap semaphore is locked. */
nilfs_bmap_set_dirty(struct nilfs_bmap * bmap)251 static inline void nilfs_bmap_set_dirty(struct nilfs_bmap *bmap)
252 {
253 bmap->b_state |= NILFS_BMAP_DIRTY;
254 }
255
256 /* Assume that bmap semaphore is locked. */
nilfs_bmap_clear_dirty(struct nilfs_bmap * bmap)257 static inline void nilfs_bmap_clear_dirty(struct nilfs_bmap *bmap)
258 {
259 bmap->b_state &= ~NILFS_BMAP_DIRTY;
260 }
261
262
263 #define NILFS_BMAP_LARGE 0x1
264
265 #define NILFS_BMAP_SMALL_LOW NILFS_DIRECT_KEY_MIN
266 #define NILFS_BMAP_SMALL_HIGH NILFS_DIRECT_KEY_MAX
267 #define NILFS_BMAP_LARGE_LOW NILFS_BTREE_ROOT_NCHILDREN_MAX
268 #define NILFS_BMAP_LARGE_HIGH NILFS_BTREE_KEY_MAX
269
270 #endif /* _NILFS_BMAP_H */
271