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65b4643d RK |
1 | /* |
2 | * the_nilfs.h - the_nilfs shared structure. | |
3 | * | |
4 | * Copyright (C) 2005-2008 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 Ryusuke Konishi <ryusuke@osrg.net> | |
21 | * | |
22 | */ | |
23 | ||
24 | #ifndef _THE_NILFS_H | |
25 | #define _THE_NILFS_H | |
26 | ||
27 | #include <linux/types.h> | |
28 | #include <linux/buffer_head.h> | |
ba65ae47 | 29 | #include <linux/rbtree.h> |
65b4643d RK |
30 | #include <linux/fs.h> |
31 | #include <linux/blkdev.h> | |
32 | #include <linux/backing-dev.h> | |
5a0e3ad6 | 33 | #include <linux/slab.h> |
65b4643d RK |
34 | #include "sb.h" |
35 | ||
36 | /* the_nilfs struct */ | |
37 | enum { | |
38 | THE_NILFS_INIT = 0, /* Information from super_block is set */ | |
39 | THE_NILFS_LOADED, /* Roll-back/roll-forward has done and | |
40 | the latest checkpoint was loaded */ | |
41 | THE_NILFS_DISCONTINUED, /* 'next' pointer chain has broken */ | |
1cf58fa8 | 42 | THE_NILFS_GC_RUNNING, /* gc process is running */ |
e605f0a7 | 43 | THE_NILFS_SB_DIRTY, /* super block is dirty */ |
65b4643d RK |
44 | }; |
45 | ||
46 | /** | |
47 | * struct the_nilfs - struct to supervise multiple nilfs mount points | |
48 | * @ns_flags: flags | |
49 | * @ns_count: reference count | |
33c8e57c | 50 | * @ns_list: list head for nilfs_list |
65b4643d RK |
51 | * @ns_bdev: block device |
52 | * @ns_bdi: backing dev info | |
53 | * @ns_writer: back pointer to writable nilfs_sb_info | |
54 | * @ns_sem: semaphore for shared states | |
aa7dfb89 | 55 | * @ns_mount_mutex: mutex protecting mount process of nilfs |
027d6404 | 56 | * @ns_writer_sem: semaphore protecting ns_writer attach/detach |
e339ad31 RK |
57 | * @ns_sbh: buffer heads of on-disk super blocks |
58 | * @ns_sbp: pointers to super block data | |
b2ac86e1 JS |
59 | * @ns_sbwtime: previous write time of super block |
60 | * @ns_sbwcount: write count of super block | |
e339ad31 | 61 | * @ns_sbsize: size of valid data in super block |
65b4643d RK |
62 | * @ns_seg_seq: segment sequence counter |
63 | * @ns_segnum: index number of the latest full segment. | |
64 | * @ns_nextnum: index number of the full segment index to be used next | |
65 | * @ns_pseg_offset: offset of next partial segment in the current full segment | |
66 | * @ns_cno: next checkpoint number | |
67 | * @ns_ctime: write time of the last segment | |
68 | * @ns_nongc_ctime: write time of the last segment not for cleaner operation | |
69 | * @ns_ndirtyblks: Number of dirty data blocks | |
70 | * @ns_last_segment_lock: lock protecting fields for the latest segment | |
71 | * @ns_last_pseg: start block number of the latest segment | |
72 | * @ns_last_seq: sequence value of the latest segment | |
73 | * @ns_last_cno: checkpoint number of the latest segment | |
2c2e52fc | 74 | * @ns_prot_seq: least sequence number of segments which must not be reclaimed |
32502047 | 75 | * @ns_prev_seq: base sequence number used to decide if advance log cursor |
65b4643d RK |
76 | * @ns_segctor_sem: segment constructor semaphore |
77 | * @ns_dat: DAT file inode | |
78 | * @ns_cpfile: checkpoint file inode | |
79 | * @ns_sufile: segusage file inode | |
80 | * @ns_gc_dat: shadow inode of the DAT file inode for GC | |
ba65ae47 RK |
81 | * @ns_cptree: rb-tree of all mounted checkpoints (nilfs_root) |
82 | * @ns_cptree_lock: lock protecting @ns_cptree | |
65b4643d | 83 | * @ns_gc_inodes: dummy inodes to keep live blocks |
65b4643d | 84 | * @ns_blocksize_bits: bit length of block size |
92c60cca | 85 | * @ns_blocksize: block size |
65b4643d RK |
86 | * @ns_nsegments: number of segments in filesystem |
87 | * @ns_blocks_per_segment: number of blocks per segment | |
88 | * @ns_r_segments_percentage: reserved segments percentage | |
89 | * @ns_nrsvsegs: number of reserved segments | |
90 | * @ns_first_data_block: block number of first data block | |
91 | * @ns_inode_size: size of on-disk inode | |
92 | * @ns_first_ino: first not-special inode number | |
93 | * @ns_crc_seed: seed value of CRC32 calculation | |
94 | */ | |
95 | struct the_nilfs { | |
96 | unsigned long ns_flags; | |
97 | atomic_t ns_count; | |
33c8e57c | 98 | struct list_head ns_list; |
65b4643d RK |
99 | |
100 | struct block_device *ns_bdev; | |
101 | struct backing_dev_info *ns_bdi; | |
102 | struct nilfs_sb_info *ns_writer; | |
103 | struct rw_semaphore ns_sem; | |
aa7dfb89 | 104 | struct mutex ns_mount_mutex; |
027d6404 | 105 | struct rw_semaphore ns_writer_sem; |
65b4643d RK |
106 | |
107 | /* | |
108 | * used for | |
109 | * - loading the latest checkpoint exclusively. | |
110 | * - allocating a new full segment. | |
111 | * - protecting s_dirt in the super_block struct | |
112 | * (see nilfs_write_super) and the following fields. | |
113 | */ | |
e339ad31 RK |
114 | struct buffer_head *ns_sbh[2]; |
115 | struct nilfs_super_block *ns_sbp[2]; | |
b2ac86e1 JS |
116 | time_t ns_sbwtime; |
117 | unsigned ns_sbwcount; | |
e339ad31 | 118 | unsigned ns_sbsize; |
65b4643d | 119 | unsigned ns_mount_state; |
65b4643d RK |
120 | |
121 | /* | |
122 | * Following fields are dedicated to a writable FS-instance. | |
123 | * Except for the period seeking checkpoint, code outside the segment | |
47420c79 RK |
124 | * constructor must lock a segment semaphore while accessing these |
125 | * fields. | |
65b4643d RK |
126 | * The writable FS-instance is sole during a lifetime of the_nilfs. |
127 | */ | |
128 | u64 ns_seg_seq; | |
129 | __u64 ns_segnum; | |
130 | __u64 ns_nextnum; | |
131 | unsigned long ns_pseg_offset; | |
132 | __u64 ns_cno; | |
133 | time_t ns_ctime; | |
134 | time_t ns_nongc_ctime; | |
135 | atomic_t ns_ndirtyblks; | |
136 | ||
137 | /* | |
138 | * The following fields hold information on the latest partial segment | |
139 | * written to disk with a super root. These fields are protected by | |
140 | * ns_last_segment_lock. | |
141 | */ | |
142 | spinlock_t ns_last_segment_lock; | |
143 | sector_t ns_last_pseg; | |
144 | u64 ns_last_seq; | |
145 | __u64 ns_last_cno; | |
2c2e52fc | 146 | u64 ns_prot_seq; |
32502047 | 147 | u64 ns_prev_seq; |
65b4643d RK |
148 | |
149 | struct rw_semaphore ns_segctor_sem; | |
150 | ||
151 | /* | |
152 | * Following fields are lock free except for the period before | |
153 | * the_nilfs is initialized. | |
154 | */ | |
155 | struct inode *ns_dat; | |
156 | struct inode *ns_cpfile; | |
157 | struct inode *ns_sufile; | |
158 | struct inode *ns_gc_dat; | |
159 | ||
ba65ae47 RK |
160 | /* Checkpoint tree */ |
161 | struct rb_root ns_cptree; | |
162 | spinlock_t ns_cptree_lock; | |
163 | ||
263d90ce | 164 | /* GC inode list */ |
65b4643d | 165 | struct list_head ns_gc_inodes; |
65b4643d | 166 | |
65b4643d RK |
167 | /* Disk layout information (static) */ |
168 | unsigned int ns_blocksize_bits; | |
92c60cca | 169 | unsigned int ns_blocksize; |
65b4643d RK |
170 | unsigned long ns_nsegments; |
171 | unsigned long ns_blocks_per_segment; | |
172 | unsigned long ns_r_segments_percentage; | |
173 | unsigned long ns_nrsvsegs; | |
174 | unsigned long ns_first_data_block; | |
175 | int ns_inode_size; | |
176 | int ns_first_ino; | |
177 | u32 ns_crc_seed; | |
178 | }; | |
179 | ||
65b4643d RK |
180 | #define THE_NILFS_FNS(bit, name) \ |
181 | static inline void set_nilfs_##name(struct the_nilfs *nilfs) \ | |
182 | { \ | |
183 | set_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ | |
184 | } \ | |
185 | static inline void clear_nilfs_##name(struct the_nilfs *nilfs) \ | |
186 | { \ | |
187 | clear_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ | |
188 | } \ | |
189 | static inline int nilfs_##name(struct the_nilfs *nilfs) \ | |
190 | { \ | |
191 | return test_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ | |
192 | } | |
193 | ||
194 | THE_NILFS_FNS(INIT, init) | |
195 | THE_NILFS_FNS(LOADED, loaded) | |
196 | THE_NILFS_FNS(DISCONTINUED, discontinued) | |
1cf58fa8 | 197 | THE_NILFS_FNS(GC_RUNNING, gc_running) |
e605f0a7 | 198 | THE_NILFS_FNS(SB_DIRTY, sb_dirty) |
65b4643d | 199 | |
ba65ae47 RK |
200 | /** |
201 | * struct nilfs_root - nilfs root object | |
202 | * @cno: checkpoint number | |
203 | * @rb_node: red-black tree node | |
204 | * @count: refcount of this structure | |
205 | * @nilfs: nilfs object | |
206 | * @ifile: inode file | |
207 | * @root: root inode | |
208 | * @inodes_count: number of inodes | |
209 | * @blocks_count: number of blocks (Reserved) | |
210 | */ | |
211 | struct nilfs_root { | |
212 | __u64 cno; | |
213 | struct rb_node rb_node; | |
214 | ||
215 | atomic_t count; | |
216 | struct the_nilfs *nilfs; | |
217 | struct inode *ifile; | |
218 | ||
219 | atomic_t inodes_count; | |
220 | atomic_t blocks_count; | |
221 | }; | |
222 | ||
223 | /* Special checkpoint number */ | |
224 | #define NILFS_CPTREE_CURRENT_CNO 0 | |
225 | ||
e339ad31 RK |
226 | /* Minimum interval of periodical update of superblocks (in seconds) */ |
227 | #define NILFS_SB_FREQ 10 | |
e339ad31 | 228 | |
79efdd94 JS |
229 | static inline int nilfs_sb_need_update(struct the_nilfs *nilfs) |
230 | { | |
231 | u64 t = get_seconds(); | |
b2ac86e1 | 232 | return t < nilfs->ns_sbwtime || t > nilfs->ns_sbwtime + NILFS_SB_FREQ; |
79efdd94 JS |
233 | } |
234 | ||
b2ac86e1 | 235 | static inline int nilfs_sb_will_flip(struct the_nilfs *nilfs) |
79efdd94 | 236 | { |
b2ac86e1 JS |
237 | int flip_bits = nilfs->ns_sbwcount & 0x0FL; |
238 | return (flip_bits != 0x08 && flip_bits != 0x0F); | |
79efdd94 JS |
239 | } |
240 | ||
65b4643d | 241 | void nilfs_set_last_segment(struct the_nilfs *, sector_t, u64, __u64); |
33c8e57c | 242 | struct the_nilfs *find_or_create_nilfs(struct block_device *); |
65b4643d RK |
243 | void put_nilfs(struct the_nilfs *); |
244 | int init_nilfs(struct the_nilfs *, struct nilfs_sb_info *, char *); | |
245 | int load_nilfs(struct the_nilfs *, struct nilfs_sb_info *); | |
e902ec99 | 246 | int nilfs_discard_segments(struct the_nilfs *, __u64 *, size_t); |
65b4643d | 247 | int nilfs_count_free_blocks(struct the_nilfs *, sector_t *); |
ba65ae47 RK |
248 | struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno); |
249 | struct nilfs_root *nilfs_find_or_create_root(struct the_nilfs *nilfs, | |
250 | __u64 cno); | |
251 | void nilfs_put_root(struct nilfs_root *root); | |
6dd47406 | 252 | struct nilfs_sb_info *nilfs_find_sbinfo(struct the_nilfs *, int, __u64); |
65b4643d RK |
253 | int nilfs_checkpoint_is_mounted(struct the_nilfs *, __u64, int); |
254 | int nilfs_near_disk_full(struct the_nilfs *); | |
e339ad31 RK |
255 | void nilfs_fall_back_super_block(struct the_nilfs *); |
256 | void nilfs_swap_super_block(struct the_nilfs *); | |
65b4643d RK |
257 | |
258 | ||
259 | static inline void get_nilfs(struct the_nilfs *nilfs) | |
260 | { | |
261 | /* Caller must have at least one reference of the_nilfs. */ | |
262 | atomic_inc(&nilfs->ns_count); | |
263 | } | |
264 | ||
ba65ae47 RK |
265 | static inline void nilfs_get_root(struct nilfs_root *root) |
266 | { | |
267 | atomic_inc(&root->count); | |
268 | } | |
269 | ||
65b4643d RK |
270 | static inline void |
271 | nilfs_attach_writer(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi) | |
272 | { | |
027d6404 | 273 | down_write(&nilfs->ns_writer_sem); |
65b4643d | 274 | nilfs->ns_writer = sbi; |
027d6404 | 275 | up_write(&nilfs->ns_writer_sem); |
65b4643d RK |
276 | } |
277 | ||
278 | static inline void | |
279 | nilfs_detach_writer(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi) | |
280 | { | |
027d6404 | 281 | down_write(&nilfs->ns_writer_sem); |
65b4643d RK |
282 | if (sbi == nilfs->ns_writer) |
283 | nilfs->ns_writer = NULL; | |
027d6404 | 284 | up_write(&nilfs->ns_writer_sem); |
65b4643d RK |
285 | } |
286 | ||
a057d2c0 RK |
287 | static inline int nilfs_valid_fs(struct the_nilfs *nilfs) |
288 | { | |
289 | unsigned valid_fs; | |
290 | ||
291 | down_read(&nilfs->ns_sem); | |
292 | valid_fs = (nilfs->ns_mount_state & NILFS_VALID_FS); | |
293 | up_read(&nilfs->ns_sem); | |
294 | return valid_fs; | |
295 | } | |
296 | ||
65b4643d RK |
297 | static inline void |
298 | nilfs_get_segment_range(struct the_nilfs *nilfs, __u64 segnum, | |
299 | sector_t *seg_start, sector_t *seg_end) | |
300 | { | |
301 | *seg_start = (sector_t)nilfs->ns_blocks_per_segment * segnum; | |
302 | *seg_end = *seg_start + nilfs->ns_blocks_per_segment - 1; | |
303 | if (segnum == 0) | |
304 | *seg_start = nilfs->ns_first_data_block; | |
305 | } | |
306 | ||
307 | static inline sector_t | |
308 | nilfs_get_segment_start_blocknr(struct the_nilfs *nilfs, __u64 segnum) | |
309 | { | |
310 | return (segnum == 0) ? nilfs->ns_first_data_block : | |
311 | (sector_t)nilfs->ns_blocks_per_segment * segnum; | |
312 | } | |
313 | ||
314 | static inline __u64 | |
315 | nilfs_get_segnum_of_block(struct the_nilfs *nilfs, sector_t blocknr) | |
316 | { | |
317 | sector_t segnum = blocknr; | |
318 | ||
319 | sector_div(segnum, nilfs->ns_blocks_per_segment); | |
320 | return segnum; | |
321 | } | |
322 | ||
323 | static inline void | |
324 | nilfs_terminate_segment(struct the_nilfs *nilfs, sector_t seg_start, | |
325 | sector_t seg_end) | |
326 | { | |
327 | /* terminate the current full segment (used in case of I/O-error) */ | |
328 | nilfs->ns_pseg_offset = seg_end - seg_start + 1; | |
329 | } | |
330 | ||
331 | static inline void nilfs_shift_to_next_segment(struct the_nilfs *nilfs) | |
332 | { | |
333 | /* move forward with a full segment */ | |
334 | nilfs->ns_segnum = nilfs->ns_nextnum; | |
335 | nilfs->ns_pseg_offset = 0; | |
336 | nilfs->ns_seg_seq++; | |
337 | } | |
338 | ||
339 | static inline __u64 nilfs_last_cno(struct the_nilfs *nilfs) | |
340 | { | |
341 | __u64 cno; | |
342 | ||
343 | spin_lock(&nilfs->ns_last_segment_lock); | |
344 | cno = nilfs->ns_last_cno; | |
345 | spin_unlock(&nilfs->ns_last_segment_lock); | |
346 | return cno; | |
347 | } | |
348 | ||
cece5520 RK |
349 | static inline int nilfs_segment_is_active(struct the_nilfs *nilfs, __u64 n) |
350 | { | |
351 | return n == nilfs->ns_segnum || n == nilfs->ns_nextnum; | |
352 | } | |
353 | ||
65b4643d | 354 | #endif /* _THE_NILFS_H */ |