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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 | |
e2c7617a | 49 | * @ns_flushed_device: flag indicating if all volatile data was flushed |
65b4643d | 50 | * @ns_bdev: block device |
65b4643d | 51 | * @ns_sem: semaphore for shared states |
572d8b39 | 52 | * @ns_snapshot_mount_mutex: mutex to protect snapshot mounts |
e339ad31 RK |
53 | * @ns_sbh: buffer heads of on-disk super blocks |
54 | * @ns_sbp: pointers to super block data | |
b2ac86e1 JS |
55 | * @ns_sbwtime: previous write time of super block |
56 | * @ns_sbwcount: write count of super block | |
e339ad31 | 57 | * @ns_sbsize: size of valid data in super block |
6b0f3393 | 58 | * @ns_mount_state: file system state |
caa05d49 | 59 | * @ns_sb_update_freq: interval of periodical update of superblocks (in seconds) |
65b4643d RK |
60 | * @ns_seg_seq: segment sequence counter |
61 | * @ns_segnum: index number of the latest full segment. | |
62 | * @ns_nextnum: index number of the full segment index to be used next | |
63 | * @ns_pseg_offset: offset of next partial segment in the current full segment | |
64 | * @ns_cno: next checkpoint number | |
65 | * @ns_ctime: write time of the last segment | |
66 | * @ns_nongc_ctime: write time of the last segment not for cleaner operation | |
67 | * @ns_ndirtyblks: Number of dirty data blocks | |
68 | * @ns_last_segment_lock: lock protecting fields for the latest segment | |
69 | * @ns_last_pseg: start block number of the latest segment | |
70 | * @ns_last_seq: sequence value of the latest segment | |
71 | * @ns_last_cno: checkpoint number of the latest segment | |
2c2e52fc | 72 | * @ns_prot_seq: least sequence number of segments which must not be reclaimed |
32502047 | 73 | * @ns_prev_seq: base sequence number used to decide if advance log cursor |
3fd3fe5a RK |
74 | * @ns_writer: log writer |
75 | * @ns_segctor_sem: semaphore protecting log write | |
65b4643d RK |
76 | * @ns_dat: DAT file inode |
77 | * @ns_cpfile: checkpoint file inode | |
78 | * @ns_sufile: segusage file inode | |
ba65ae47 RK |
79 | * @ns_cptree: rb-tree of all mounted checkpoints (nilfs_root) |
80 | * @ns_cptree_lock: lock protecting @ns_cptree | |
693dd321 RK |
81 | * @ns_dirty_files: list of dirty files |
82 | * @ns_inode_lock: lock protecting @ns_dirty_files | |
65b4643d | 83 | * @ns_gc_inodes: dummy inodes to keep live blocks |
9b1fc4e4 RK |
84 | * @ns_next_generation: next generation number for inodes |
85 | * @ns_next_gen_lock: lock protecting @ns_next_generation | |
3b2ce58b | 86 | * @ns_mount_opt: mount options |
574e6c31 RK |
87 | * @ns_resuid: uid for reserved blocks |
88 | * @ns_resgid: gid for reserved blocks | |
89 | * @ns_interval: checkpoint creation interval | |
90 | * @ns_watermark: watermark for the number of dirty buffers | |
65b4643d | 91 | * @ns_blocksize_bits: bit length of block size |
92c60cca | 92 | * @ns_blocksize: block size |
65b4643d RK |
93 | * @ns_nsegments: number of segments in filesystem |
94 | * @ns_blocks_per_segment: number of blocks per segment | |
95 | * @ns_r_segments_percentage: reserved segments percentage | |
96 | * @ns_nrsvsegs: number of reserved segments | |
97 | * @ns_first_data_block: block number of first data block | |
98 | * @ns_inode_size: size of on-disk inode | |
99 | * @ns_first_ino: first not-special inode number | |
100 | * @ns_crc_seed: seed value of CRC32 calculation | |
da7141fb VD |
101 | * @ns_dev_kobj: /sys/fs/<nilfs>/<device> |
102 | * @ns_dev_kobj_unregister: completion state | |
caa05d49 | 103 | * @ns_dev_subgroups: <device> subgroups pointer |
65b4643d RK |
104 | */ |
105 | struct the_nilfs { | |
106 | unsigned long ns_flags; | |
e2c7617a | 107 | int ns_flushed_device; |
65b4643d RK |
108 | |
109 | struct block_device *ns_bdev; | |
65b4643d | 110 | struct rw_semaphore ns_sem; |
572d8b39 | 111 | struct mutex ns_snapshot_mount_mutex; |
65b4643d RK |
112 | |
113 | /* | |
114 | * used for | |
115 | * - loading the latest checkpoint exclusively. | |
116 | * - allocating a new full segment. | |
65b4643d | 117 | */ |
e339ad31 RK |
118 | struct buffer_head *ns_sbh[2]; |
119 | struct nilfs_super_block *ns_sbp[2]; | |
b2ac86e1 JS |
120 | time_t ns_sbwtime; |
121 | unsigned ns_sbwcount; | |
e339ad31 | 122 | unsigned ns_sbsize; |
65b4643d | 123 | unsigned ns_mount_state; |
caa05d49 | 124 | unsigned ns_sb_update_freq; |
65b4643d RK |
125 | |
126 | /* | |
127 | * Following fields are dedicated to a writable FS-instance. | |
128 | * Except for the period seeking checkpoint, code outside the segment | |
47420c79 RK |
129 | * constructor must lock a segment semaphore while accessing these |
130 | * fields. | |
65b4643d RK |
131 | * The writable FS-instance is sole during a lifetime of the_nilfs. |
132 | */ | |
133 | u64 ns_seg_seq; | |
134 | __u64 ns_segnum; | |
135 | __u64 ns_nextnum; | |
136 | unsigned long ns_pseg_offset; | |
137 | __u64 ns_cno; | |
138 | time_t ns_ctime; | |
139 | time_t ns_nongc_ctime; | |
140 | atomic_t ns_ndirtyblks; | |
141 | ||
142 | /* | |
143 | * The following fields hold information on the latest partial segment | |
144 | * written to disk with a super root. These fields are protected by | |
145 | * ns_last_segment_lock. | |
146 | */ | |
147 | spinlock_t ns_last_segment_lock; | |
148 | sector_t ns_last_pseg; | |
149 | u64 ns_last_seq; | |
150 | __u64 ns_last_cno; | |
2c2e52fc | 151 | u64 ns_prot_seq; |
32502047 | 152 | u64 ns_prev_seq; |
65b4643d | 153 | |
3fd3fe5a | 154 | struct nilfs_sc_info *ns_writer; |
65b4643d RK |
155 | struct rw_semaphore ns_segctor_sem; |
156 | ||
157 | /* | |
158 | * Following fields are lock free except for the period before | |
159 | * the_nilfs is initialized. | |
160 | */ | |
161 | struct inode *ns_dat; | |
162 | struct inode *ns_cpfile; | |
163 | struct inode *ns_sufile; | |
65b4643d | 164 | |
ba65ae47 RK |
165 | /* Checkpoint tree */ |
166 | struct rb_root ns_cptree; | |
167 | spinlock_t ns_cptree_lock; | |
168 | ||
693dd321 RK |
169 | /* Dirty inode list */ |
170 | struct list_head ns_dirty_files; | |
171 | spinlock_t ns_inode_lock; | |
172 | ||
263d90ce | 173 | /* GC inode list */ |
65b4643d | 174 | struct list_head ns_gc_inodes; |
65b4643d | 175 | |
9b1fc4e4 RK |
176 | /* Inode allocator */ |
177 | u32 ns_next_generation; | |
178 | spinlock_t ns_next_gen_lock; | |
179 | ||
3b2ce58b RK |
180 | /* Mount options */ |
181 | unsigned long ns_mount_opt; | |
182 | ||
574e6c31 RK |
183 | uid_t ns_resuid; |
184 | gid_t ns_resgid; | |
185 | unsigned long ns_interval; | |
186 | unsigned long ns_watermark; | |
187 | ||
65b4643d RK |
188 | /* Disk layout information (static) */ |
189 | unsigned int ns_blocksize_bits; | |
92c60cca | 190 | unsigned int ns_blocksize; |
65b4643d RK |
191 | unsigned long ns_nsegments; |
192 | unsigned long ns_blocks_per_segment; | |
193 | unsigned long ns_r_segments_percentage; | |
194 | unsigned long ns_nrsvsegs; | |
195 | unsigned long ns_first_data_block; | |
196 | int ns_inode_size; | |
197 | int ns_first_ino; | |
198 | u32 ns_crc_seed; | |
da7141fb VD |
199 | |
200 | /* /sys/fs/<nilfs>/<device> */ | |
201 | struct kobject ns_dev_kobj; | |
202 | struct completion ns_dev_kobj_unregister; | |
caa05d49 | 203 | struct nilfs_sysfs_dev_subgroups *ns_dev_subgroups; |
65b4643d RK |
204 | }; |
205 | ||
65b4643d RK |
206 | #define THE_NILFS_FNS(bit, name) \ |
207 | static inline void set_nilfs_##name(struct the_nilfs *nilfs) \ | |
208 | { \ | |
209 | set_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ | |
210 | } \ | |
211 | static inline void clear_nilfs_##name(struct the_nilfs *nilfs) \ | |
212 | { \ | |
213 | clear_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ | |
214 | } \ | |
215 | static inline int nilfs_##name(struct the_nilfs *nilfs) \ | |
216 | { \ | |
217 | return test_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ | |
218 | } | |
219 | ||
220 | THE_NILFS_FNS(INIT, init) | |
65b4643d | 221 | THE_NILFS_FNS(DISCONTINUED, discontinued) |
1cf58fa8 | 222 | THE_NILFS_FNS(GC_RUNNING, gc_running) |
e605f0a7 | 223 | THE_NILFS_FNS(SB_DIRTY, sb_dirty) |
65b4643d | 224 | |
3b2ce58b RK |
225 | /* |
226 | * Mount option operations | |
227 | */ | |
228 | #define nilfs_clear_opt(nilfs, opt) \ | |
229 | do { (nilfs)->ns_mount_opt &= ~NILFS_MOUNT_##opt; } while (0) | |
230 | #define nilfs_set_opt(nilfs, opt) \ | |
231 | do { (nilfs)->ns_mount_opt |= NILFS_MOUNT_##opt; } while (0) | |
232 | #define nilfs_test_opt(nilfs, opt) ((nilfs)->ns_mount_opt & NILFS_MOUNT_##opt) | |
233 | #define nilfs_write_opt(nilfs, mask, opt) \ | |
234 | do { (nilfs)->ns_mount_opt = \ | |
235 | (((nilfs)->ns_mount_opt & ~NILFS_MOUNT_##mask) | \ | |
236 | NILFS_MOUNT_##opt); \ | |
237 | } while (0) | |
238 | ||
ba65ae47 RK |
239 | /** |
240 | * struct nilfs_root - nilfs root object | |
241 | * @cno: checkpoint number | |
242 | * @rb_node: red-black tree node | |
243 | * @count: refcount of this structure | |
244 | * @nilfs: nilfs object | |
245 | * @ifile: inode file | |
ba65ae47 | 246 | * @inodes_count: number of inodes |
f5974c8f | 247 | * @blocks_count: number of blocks |
a5a7332a VD |
248 | * @snapshot_kobj: /sys/fs/<nilfs>/<device>/mounted_snapshots/<snapshot> |
249 | * @snapshot_kobj_unregister: completion state for kernel object | |
ba65ae47 RK |
250 | */ |
251 | struct nilfs_root { | |
252 | __u64 cno; | |
253 | struct rb_node rb_node; | |
254 | ||
255 | atomic_t count; | |
256 | struct the_nilfs *nilfs; | |
257 | struct inode *ifile; | |
258 | ||
e5f7f848 VD |
259 | atomic64_t inodes_count; |
260 | atomic64_t blocks_count; | |
a5a7332a VD |
261 | |
262 | /* /sys/fs/<nilfs>/<device>/mounted_snapshots/<snapshot> */ | |
263 | struct kobject snapshot_kobj; | |
264 | struct completion snapshot_kobj_unregister; | |
ba65ae47 RK |
265 | }; |
266 | ||
267 | /* Special checkpoint number */ | |
268 | #define NILFS_CPTREE_CURRENT_CNO 0 | |
269 | ||
e339ad31 RK |
270 | /* Minimum interval of periodical update of superblocks (in seconds) */ |
271 | #define NILFS_SB_FREQ 10 | |
e339ad31 | 272 | |
79efdd94 JS |
273 | static inline int nilfs_sb_need_update(struct the_nilfs *nilfs) |
274 | { | |
275 | u64 t = get_seconds(); | |
caa05d49 VD |
276 | return t < nilfs->ns_sbwtime || |
277 | t > nilfs->ns_sbwtime + nilfs->ns_sb_update_freq; | |
79efdd94 JS |
278 | } |
279 | ||
b2ac86e1 | 280 | static inline int nilfs_sb_will_flip(struct the_nilfs *nilfs) |
79efdd94 | 281 | { |
b2ac86e1 JS |
282 | int flip_bits = nilfs->ns_sbwcount & 0x0FL; |
283 | return (flip_bits != 0x08 && flip_bits != 0x0F); | |
79efdd94 JS |
284 | } |
285 | ||
65b4643d | 286 | void nilfs_set_last_segment(struct the_nilfs *, sector_t, u64, __u64); |
348fe8da RK |
287 | struct the_nilfs *alloc_nilfs(struct block_device *bdev); |
288 | void destroy_nilfs(struct the_nilfs *nilfs); | |
f7545144 RK |
289 | int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data); |
290 | int load_nilfs(struct the_nilfs *nilfs, struct super_block *sb); | |
4e33f9ea RK |
291 | unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs); |
292 | void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs); | |
e902ec99 | 293 | int nilfs_discard_segments(struct the_nilfs *, __u64 *, size_t); |
65b4643d | 294 | int nilfs_count_free_blocks(struct the_nilfs *, sector_t *); |
ba65ae47 RK |
295 | struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno); |
296 | struct nilfs_root *nilfs_find_or_create_root(struct the_nilfs *nilfs, | |
297 | __u64 cno); | |
298 | void nilfs_put_root(struct nilfs_root *root); | |
65b4643d | 299 | int nilfs_near_disk_full(struct the_nilfs *); |
e339ad31 RK |
300 | void nilfs_fall_back_super_block(struct the_nilfs *); |
301 | void nilfs_swap_super_block(struct the_nilfs *); | |
65b4643d RK |
302 | |
303 | ||
ba65ae47 RK |
304 | static inline void nilfs_get_root(struct nilfs_root *root) |
305 | { | |
306 | atomic_inc(&root->count); | |
307 | } | |
308 | ||
a057d2c0 RK |
309 | static inline int nilfs_valid_fs(struct the_nilfs *nilfs) |
310 | { | |
311 | unsigned valid_fs; | |
312 | ||
313 | down_read(&nilfs->ns_sem); | |
314 | valid_fs = (nilfs->ns_mount_state & NILFS_VALID_FS); | |
315 | up_read(&nilfs->ns_sem); | |
316 | return valid_fs; | |
317 | } | |
318 | ||
65b4643d RK |
319 | static inline void |
320 | nilfs_get_segment_range(struct the_nilfs *nilfs, __u64 segnum, | |
321 | sector_t *seg_start, sector_t *seg_end) | |
322 | { | |
323 | *seg_start = (sector_t)nilfs->ns_blocks_per_segment * segnum; | |
324 | *seg_end = *seg_start + nilfs->ns_blocks_per_segment - 1; | |
325 | if (segnum == 0) | |
326 | *seg_start = nilfs->ns_first_data_block; | |
327 | } | |
328 | ||
329 | static inline sector_t | |
330 | nilfs_get_segment_start_blocknr(struct the_nilfs *nilfs, __u64 segnum) | |
331 | { | |
332 | return (segnum == 0) ? nilfs->ns_first_data_block : | |
333 | (sector_t)nilfs->ns_blocks_per_segment * segnum; | |
334 | } | |
335 | ||
336 | static inline __u64 | |
337 | nilfs_get_segnum_of_block(struct the_nilfs *nilfs, sector_t blocknr) | |
338 | { | |
339 | sector_t segnum = blocknr; | |
340 | ||
341 | sector_div(segnum, nilfs->ns_blocks_per_segment); | |
342 | return segnum; | |
343 | } | |
344 | ||
345 | static inline void | |
346 | nilfs_terminate_segment(struct the_nilfs *nilfs, sector_t seg_start, | |
347 | sector_t seg_end) | |
348 | { | |
349 | /* terminate the current full segment (used in case of I/O-error) */ | |
350 | nilfs->ns_pseg_offset = seg_end - seg_start + 1; | |
351 | } | |
352 | ||
353 | static inline void nilfs_shift_to_next_segment(struct the_nilfs *nilfs) | |
354 | { | |
355 | /* move forward with a full segment */ | |
356 | nilfs->ns_segnum = nilfs->ns_nextnum; | |
357 | nilfs->ns_pseg_offset = 0; | |
358 | nilfs->ns_seg_seq++; | |
359 | } | |
360 | ||
361 | static inline __u64 nilfs_last_cno(struct the_nilfs *nilfs) | |
362 | { | |
363 | __u64 cno; | |
364 | ||
365 | spin_lock(&nilfs->ns_last_segment_lock); | |
366 | cno = nilfs->ns_last_cno; | |
367 | spin_unlock(&nilfs->ns_last_segment_lock); | |
368 | return cno; | |
369 | } | |
370 | ||
cece5520 RK |
371 | static inline int nilfs_segment_is_active(struct the_nilfs *nilfs, __u64 n) |
372 | { | |
373 | return n == nilfs->ns_segnum || n == nilfs->ns_nextnum; | |
374 | } | |
375 | ||
e2c7617a AR |
376 | static inline int nilfs_flush_device(struct the_nilfs *nilfs) |
377 | { | |
378 | int err; | |
379 | ||
380 | if (!nilfs_test_opt(nilfs, BARRIER) || nilfs->ns_flushed_device) | |
381 | return 0; | |
382 | ||
383 | nilfs->ns_flushed_device = 1; | |
384 | /* | |
385 | * the store to ns_flushed_device must not be reordered after | |
386 | * blkdev_issue_flush(). | |
387 | */ | |
388 | smp_wmb(); | |
389 | ||
390 | err = blkdev_issue_flush(nilfs->ns_bdev, GFP_KERNEL, NULL); | |
391 | if (err != -EIO) | |
392 | err = 0; | |
393 | return err; | |
394 | } | |
395 | ||
65b4643d | 396 | #endif /* _THE_NILFS_H */ |