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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 | 34 | |
3fd3fe5a | 35 | struct nilfs_sc_info; |
caa05d49 | 36 | struct nilfs_sysfs_dev_subgroups; |
3fd3fe5a | 37 | |
65b4643d RK |
38 | /* the_nilfs struct */ |
39 | enum { | |
40 | THE_NILFS_INIT = 0, /* Information from super_block is set */ | |
65b4643d | 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 | |
65b4643d | 49 | * @ns_bdev: block device |
65b4643d | 50 | * @ns_sem: semaphore for shared states |
572d8b39 | 51 | * @ns_snapshot_mount_mutex: mutex to protect snapshot mounts |
e339ad31 RK |
52 | * @ns_sbh: buffer heads of on-disk super blocks |
53 | * @ns_sbp: pointers to super block data | |
b2ac86e1 JS |
54 | * @ns_sbwtime: previous write time of super block |
55 | * @ns_sbwcount: write count of super block | |
e339ad31 | 56 | * @ns_sbsize: size of valid data in super block |
6b0f3393 | 57 | * @ns_mount_state: file system state |
caa05d49 | 58 | * @ns_sb_update_freq: interval of periodical update of superblocks (in seconds) |
65b4643d RK |
59 | * @ns_seg_seq: segment sequence counter |
60 | * @ns_segnum: index number of the latest full segment. | |
61 | * @ns_nextnum: index number of the full segment index to be used next | |
62 | * @ns_pseg_offset: offset of next partial segment in the current full segment | |
63 | * @ns_cno: next checkpoint number | |
64 | * @ns_ctime: write time of the last segment | |
65 | * @ns_nongc_ctime: write time of the last segment not for cleaner operation | |
66 | * @ns_ndirtyblks: Number of dirty data blocks | |
67 | * @ns_last_segment_lock: lock protecting fields for the latest segment | |
68 | * @ns_last_pseg: start block number of the latest segment | |
69 | * @ns_last_seq: sequence value of the latest segment | |
70 | * @ns_last_cno: checkpoint number of the latest segment | |
2c2e52fc | 71 | * @ns_prot_seq: least sequence number of segments which must not be reclaimed |
32502047 | 72 | * @ns_prev_seq: base sequence number used to decide if advance log cursor |
3fd3fe5a RK |
73 | * @ns_writer: log writer |
74 | * @ns_segctor_sem: semaphore protecting log write | |
65b4643d RK |
75 | * @ns_dat: DAT file inode |
76 | * @ns_cpfile: checkpoint file inode | |
77 | * @ns_sufile: segusage file inode | |
ba65ae47 RK |
78 | * @ns_cptree: rb-tree of all mounted checkpoints (nilfs_root) |
79 | * @ns_cptree_lock: lock protecting @ns_cptree | |
693dd321 RK |
80 | * @ns_dirty_files: list of dirty files |
81 | * @ns_inode_lock: lock protecting @ns_dirty_files | |
65b4643d | 82 | * @ns_gc_inodes: dummy inodes to keep live blocks |
9b1fc4e4 RK |
83 | * @ns_next_generation: next generation number for inodes |
84 | * @ns_next_gen_lock: lock protecting @ns_next_generation | |
3b2ce58b | 85 | * @ns_mount_opt: mount options |
574e6c31 RK |
86 | * @ns_resuid: uid for reserved blocks |
87 | * @ns_resgid: gid for reserved blocks | |
88 | * @ns_interval: checkpoint creation interval | |
89 | * @ns_watermark: watermark for the number of dirty buffers | |
65b4643d | 90 | * @ns_blocksize_bits: bit length of block size |
92c60cca | 91 | * @ns_blocksize: block size |
65b4643d RK |
92 | * @ns_nsegments: number of segments in filesystem |
93 | * @ns_blocks_per_segment: number of blocks per segment | |
94 | * @ns_r_segments_percentage: reserved segments percentage | |
95 | * @ns_nrsvsegs: number of reserved segments | |
96 | * @ns_first_data_block: block number of first data block | |
97 | * @ns_inode_size: size of on-disk inode | |
98 | * @ns_first_ino: first not-special inode number | |
99 | * @ns_crc_seed: seed value of CRC32 calculation | |
da7141fb VD |
100 | * @ns_dev_kobj: /sys/fs/<nilfs>/<device> |
101 | * @ns_dev_kobj_unregister: completion state | |
caa05d49 | 102 | * @ns_dev_subgroups: <device> subgroups pointer |
65b4643d RK |
103 | */ |
104 | struct the_nilfs { | |
105 | unsigned long ns_flags; | |
65b4643d RK |
106 | |
107 | struct block_device *ns_bdev; | |
65b4643d | 108 | struct rw_semaphore ns_sem; |
572d8b39 | 109 | struct mutex ns_snapshot_mount_mutex; |
65b4643d RK |
110 | |
111 | /* | |
112 | * used for | |
113 | * - loading the latest checkpoint exclusively. | |
114 | * - allocating a new full segment. | |
65b4643d | 115 | */ |
e339ad31 RK |
116 | struct buffer_head *ns_sbh[2]; |
117 | struct nilfs_super_block *ns_sbp[2]; | |
b2ac86e1 JS |
118 | time_t ns_sbwtime; |
119 | unsigned ns_sbwcount; | |
e339ad31 | 120 | unsigned ns_sbsize; |
65b4643d | 121 | unsigned ns_mount_state; |
caa05d49 | 122 | unsigned ns_sb_update_freq; |
65b4643d RK |
123 | |
124 | /* | |
125 | * Following fields are dedicated to a writable FS-instance. | |
126 | * Except for the period seeking checkpoint, code outside the segment | |
47420c79 RK |
127 | * constructor must lock a segment semaphore while accessing these |
128 | * fields. | |
65b4643d RK |
129 | * The writable FS-instance is sole during a lifetime of the_nilfs. |
130 | */ | |
131 | u64 ns_seg_seq; | |
132 | __u64 ns_segnum; | |
133 | __u64 ns_nextnum; | |
134 | unsigned long ns_pseg_offset; | |
135 | __u64 ns_cno; | |
136 | time_t ns_ctime; | |
137 | time_t ns_nongc_ctime; | |
138 | atomic_t ns_ndirtyblks; | |
139 | ||
140 | /* | |
141 | * The following fields hold information on the latest partial segment | |
142 | * written to disk with a super root. These fields are protected by | |
143 | * ns_last_segment_lock. | |
144 | */ | |
145 | spinlock_t ns_last_segment_lock; | |
146 | sector_t ns_last_pseg; | |
147 | u64 ns_last_seq; | |
148 | __u64 ns_last_cno; | |
2c2e52fc | 149 | u64 ns_prot_seq; |
32502047 | 150 | u64 ns_prev_seq; |
65b4643d | 151 | |
3fd3fe5a | 152 | struct nilfs_sc_info *ns_writer; |
65b4643d RK |
153 | struct rw_semaphore ns_segctor_sem; |
154 | ||
155 | /* | |
156 | * Following fields are lock free except for the period before | |
157 | * the_nilfs is initialized. | |
158 | */ | |
159 | struct inode *ns_dat; | |
160 | struct inode *ns_cpfile; | |
161 | struct inode *ns_sufile; | |
65b4643d | 162 | |
ba65ae47 RK |
163 | /* Checkpoint tree */ |
164 | struct rb_root ns_cptree; | |
165 | spinlock_t ns_cptree_lock; | |
166 | ||
693dd321 RK |
167 | /* Dirty inode list */ |
168 | struct list_head ns_dirty_files; | |
169 | spinlock_t ns_inode_lock; | |
170 | ||
263d90ce | 171 | /* GC inode list */ |
65b4643d | 172 | struct list_head ns_gc_inodes; |
65b4643d | 173 | |
9b1fc4e4 RK |
174 | /* Inode allocator */ |
175 | u32 ns_next_generation; | |
176 | spinlock_t ns_next_gen_lock; | |
177 | ||
3b2ce58b RK |
178 | /* Mount options */ |
179 | unsigned long ns_mount_opt; | |
180 | ||
574e6c31 RK |
181 | uid_t ns_resuid; |
182 | gid_t ns_resgid; | |
183 | unsigned long ns_interval; | |
184 | unsigned long ns_watermark; | |
185 | ||
65b4643d RK |
186 | /* Disk layout information (static) */ |
187 | unsigned int ns_blocksize_bits; | |
92c60cca | 188 | unsigned int ns_blocksize; |
65b4643d RK |
189 | unsigned long ns_nsegments; |
190 | unsigned long ns_blocks_per_segment; | |
191 | unsigned long ns_r_segments_percentage; | |
192 | unsigned long ns_nrsvsegs; | |
193 | unsigned long ns_first_data_block; | |
194 | int ns_inode_size; | |
195 | int ns_first_ino; | |
196 | u32 ns_crc_seed; | |
da7141fb VD |
197 | |
198 | /* /sys/fs/<nilfs>/<device> */ | |
199 | struct kobject ns_dev_kobj; | |
200 | struct completion ns_dev_kobj_unregister; | |
caa05d49 | 201 | struct nilfs_sysfs_dev_subgroups *ns_dev_subgroups; |
65b4643d RK |
202 | }; |
203 | ||
65b4643d RK |
204 | #define THE_NILFS_FNS(bit, name) \ |
205 | static inline void set_nilfs_##name(struct the_nilfs *nilfs) \ | |
206 | { \ | |
207 | set_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ | |
208 | } \ | |
209 | static inline void clear_nilfs_##name(struct the_nilfs *nilfs) \ | |
210 | { \ | |
211 | clear_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ | |
212 | } \ | |
213 | static inline int nilfs_##name(struct the_nilfs *nilfs) \ | |
214 | { \ | |
215 | return test_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ | |
216 | } | |
217 | ||
218 | THE_NILFS_FNS(INIT, init) | |
65b4643d | 219 | THE_NILFS_FNS(DISCONTINUED, discontinued) |
1cf58fa8 | 220 | THE_NILFS_FNS(GC_RUNNING, gc_running) |
e605f0a7 | 221 | THE_NILFS_FNS(SB_DIRTY, sb_dirty) |
65b4643d | 222 | |
3b2ce58b RK |
223 | /* |
224 | * Mount option operations | |
225 | */ | |
226 | #define nilfs_clear_opt(nilfs, opt) \ | |
227 | do { (nilfs)->ns_mount_opt &= ~NILFS_MOUNT_##opt; } while (0) | |
228 | #define nilfs_set_opt(nilfs, opt) \ | |
229 | do { (nilfs)->ns_mount_opt |= NILFS_MOUNT_##opt; } while (0) | |
230 | #define nilfs_test_opt(nilfs, opt) ((nilfs)->ns_mount_opt & NILFS_MOUNT_##opt) | |
231 | #define nilfs_write_opt(nilfs, mask, opt) \ | |
232 | do { (nilfs)->ns_mount_opt = \ | |
233 | (((nilfs)->ns_mount_opt & ~NILFS_MOUNT_##mask) | \ | |
234 | NILFS_MOUNT_##opt); \ | |
235 | } while (0) | |
236 | ||
ba65ae47 RK |
237 | /** |
238 | * struct nilfs_root - nilfs root object | |
239 | * @cno: checkpoint number | |
240 | * @rb_node: red-black tree node | |
241 | * @count: refcount of this structure | |
242 | * @nilfs: nilfs object | |
243 | * @ifile: inode file | |
ba65ae47 | 244 | * @inodes_count: number of inodes |
f5974c8f | 245 | * @blocks_count: number of blocks |
a5a7332a VD |
246 | * @snapshot_kobj: /sys/fs/<nilfs>/<device>/mounted_snapshots/<snapshot> |
247 | * @snapshot_kobj_unregister: completion state for kernel object | |
ba65ae47 RK |
248 | */ |
249 | struct nilfs_root { | |
250 | __u64 cno; | |
251 | struct rb_node rb_node; | |
252 | ||
253 | atomic_t count; | |
254 | struct the_nilfs *nilfs; | |
255 | struct inode *ifile; | |
256 | ||
e5f7f848 VD |
257 | atomic64_t inodes_count; |
258 | atomic64_t blocks_count; | |
a5a7332a VD |
259 | |
260 | /* /sys/fs/<nilfs>/<device>/mounted_snapshots/<snapshot> */ | |
261 | struct kobject snapshot_kobj; | |
262 | struct completion snapshot_kobj_unregister; | |
ba65ae47 RK |
263 | }; |
264 | ||
265 | /* Special checkpoint number */ | |
266 | #define NILFS_CPTREE_CURRENT_CNO 0 | |
267 | ||
e339ad31 RK |
268 | /* Minimum interval of periodical update of superblocks (in seconds) */ |
269 | #define NILFS_SB_FREQ 10 | |
e339ad31 | 270 | |
79efdd94 JS |
271 | static inline int nilfs_sb_need_update(struct the_nilfs *nilfs) |
272 | { | |
273 | u64 t = get_seconds(); | |
caa05d49 VD |
274 | return t < nilfs->ns_sbwtime || |
275 | t > nilfs->ns_sbwtime + nilfs->ns_sb_update_freq; | |
79efdd94 JS |
276 | } |
277 | ||
b2ac86e1 | 278 | static inline int nilfs_sb_will_flip(struct the_nilfs *nilfs) |
79efdd94 | 279 | { |
b2ac86e1 JS |
280 | int flip_bits = nilfs->ns_sbwcount & 0x0FL; |
281 | return (flip_bits != 0x08 && flip_bits != 0x0F); | |
79efdd94 JS |
282 | } |
283 | ||
65b4643d | 284 | void nilfs_set_last_segment(struct the_nilfs *, sector_t, u64, __u64); |
348fe8da RK |
285 | struct the_nilfs *alloc_nilfs(struct block_device *bdev); |
286 | void destroy_nilfs(struct the_nilfs *nilfs); | |
f7545144 RK |
287 | int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data); |
288 | int load_nilfs(struct the_nilfs *nilfs, struct super_block *sb); | |
4e33f9ea RK |
289 | unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs); |
290 | void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs); | |
e902ec99 | 291 | int nilfs_discard_segments(struct the_nilfs *, __u64 *, size_t); |
65b4643d | 292 | int nilfs_count_free_blocks(struct the_nilfs *, sector_t *); |
ba65ae47 RK |
293 | struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno); |
294 | struct nilfs_root *nilfs_find_or_create_root(struct the_nilfs *nilfs, | |
295 | __u64 cno); | |
296 | void nilfs_put_root(struct nilfs_root *root); | |
65b4643d | 297 | int nilfs_near_disk_full(struct the_nilfs *); |
e339ad31 RK |
298 | void nilfs_fall_back_super_block(struct the_nilfs *); |
299 | void nilfs_swap_super_block(struct the_nilfs *); | |
65b4643d RK |
300 | |
301 | ||
ba65ae47 RK |
302 | static inline void nilfs_get_root(struct nilfs_root *root) |
303 | { | |
304 | atomic_inc(&root->count); | |
305 | } | |
306 | ||
a057d2c0 RK |
307 | static inline int nilfs_valid_fs(struct the_nilfs *nilfs) |
308 | { | |
309 | unsigned valid_fs; | |
310 | ||
311 | down_read(&nilfs->ns_sem); | |
312 | valid_fs = (nilfs->ns_mount_state & NILFS_VALID_FS); | |
313 | up_read(&nilfs->ns_sem); | |
314 | return valid_fs; | |
315 | } | |
316 | ||
65b4643d RK |
317 | static inline void |
318 | nilfs_get_segment_range(struct the_nilfs *nilfs, __u64 segnum, | |
319 | sector_t *seg_start, sector_t *seg_end) | |
320 | { | |
321 | *seg_start = (sector_t)nilfs->ns_blocks_per_segment * segnum; | |
322 | *seg_end = *seg_start + nilfs->ns_blocks_per_segment - 1; | |
323 | if (segnum == 0) | |
324 | *seg_start = nilfs->ns_first_data_block; | |
325 | } | |
326 | ||
327 | static inline sector_t | |
328 | nilfs_get_segment_start_blocknr(struct the_nilfs *nilfs, __u64 segnum) | |
329 | { | |
330 | return (segnum == 0) ? nilfs->ns_first_data_block : | |
331 | (sector_t)nilfs->ns_blocks_per_segment * segnum; | |
332 | } | |
333 | ||
334 | static inline __u64 | |
335 | nilfs_get_segnum_of_block(struct the_nilfs *nilfs, sector_t blocknr) | |
336 | { | |
337 | sector_t segnum = blocknr; | |
338 | ||
339 | sector_div(segnum, nilfs->ns_blocks_per_segment); | |
340 | return segnum; | |
341 | } | |
342 | ||
343 | static inline void | |
344 | nilfs_terminate_segment(struct the_nilfs *nilfs, sector_t seg_start, | |
345 | sector_t seg_end) | |
346 | { | |
347 | /* terminate the current full segment (used in case of I/O-error) */ | |
348 | nilfs->ns_pseg_offset = seg_end - seg_start + 1; | |
349 | } | |
350 | ||
351 | static inline void nilfs_shift_to_next_segment(struct the_nilfs *nilfs) | |
352 | { | |
353 | /* move forward with a full segment */ | |
354 | nilfs->ns_segnum = nilfs->ns_nextnum; | |
355 | nilfs->ns_pseg_offset = 0; | |
356 | nilfs->ns_seg_seq++; | |
357 | } | |
358 | ||
359 | static inline __u64 nilfs_last_cno(struct the_nilfs *nilfs) | |
360 | { | |
361 | __u64 cno; | |
362 | ||
363 | spin_lock(&nilfs->ns_last_segment_lock); | |
364 | cno = nilfs->ns_last_cno; | |
365 | spin_unlock(&nilfs->ns_last_segment_lock); | |
366 | return cno; | |
367 | } | |
368 | ||
cece5520 RK |
369 | static inline int nilfs_segment_is_active(struct the_nilfs *nilfs, __u64 n) |
370 | { | |
371 | return n == nilfs->ns_segnum || n == nilfs->ns_nextnum; | |
372 | } | |
373 | ||
65b4643d | 374 | #endif /* _THE_NILFS_H */ |