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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 | * | |
4b420ab4 | 16 | * Written by Ryusuke Konishi. |
65b4643d RK |
17 | * |
18 | */ | |
19 | ||
20 | #ifndef _THE_NILFS_H | |
21 | #define _THE_NILFS_H | |
22 | ||
23 | #include <linux/types.h> | |
24 | #include <linux/buffer_head.h> | |
ba65ae47 | 25 | #include <linux/rbtree.h> |
65b4643d RK |
26 | #include <linux/fs.h> |
27 | #include <linux/blkdev.h> | |
28 | #include <linux/backing-dev.h> | |
5a0e3ad6 | 29 | #include <linux/slab.h> |
65b4643d | 30 | |
3fd3fe5a | 31 | struct nilfs_sc_info; |
caa05d49 | 32 | struct nilfs_sysfs_dev_subgroups; |
3fd3fe5a | 33 | |
65b4643d RK |
34 | /* the_nilfs struct */ |
35 | enum { | |
36 | THE_NILFS_INIT = 0, /* Information from super_block is set */ | |
65b4643d | 37 | THE_NILFS_DISCONTINUED, /* 'next' pointer chain has broken */ |
1cf58fa8 | 38 | THE_NILFS_GC_RUNNING, /* gc process is running */ |
e605f0a7 | 39 | THE_NILFS_SB_DIRTY, /* super block is dirty */ |
65b4643d RK |
40 | }; |
41 | ||
42 | /** | |
43 | * struct the_nilfs - struct to supervise multiple nilfs mount points | |
44 | * @ns_flags: flags | |
e2c7617a | 45 | * @ns_flushed_device: flag indicating if all volatile data was flushed |
6625689e | 46 | * @ns_sb: back pointer to super block instance |
65b4643d | 47 | * @ns_bdev: block device |
65b4643d | 48 | * @ns_sem: semaphore for shared states |
572d8b39 | 49 | * @ns_snapshot_mount_mutex: mutex to protect snapshot mounts |
e339ad31 RK |
50 | * @ns_sbh: buffer heads of on-disk super blocks |
51 | * @ns_sbp: pointers to super block data | |
b2ac86e1 JS |
52 | * @ns_sbwtime: previous write time of super block |
53 | * @ns_sbwcount: write count of super block | |
e339ad31 | 54 | * @ns_sbsize: size of valid data in super block |
6b0f3393 | 55 | * @ns_mount_state: file system state |
caa05d49 | 56 | * @ns_sb_update_freq: interval of periodical update of superblocks (in seconds) |
65b4643d RK |
57 | * @ns_seg_seq: segment sequence counter |
58 | * @ns_segnum: index number of the latest full segment. | |
59 | * @ns_nextnum: index number of the full segment index to be used next | |
60 | * @ns_pseg_offset: offset of next partial segment in the current full segment | |
61 | * @ns_cno: next checkpoint number | |
62 | * @ns_ctime: write time of the last segment | |
63 | * @ns_nongc_ctime: write time of the last segment not for cleaner operation | |
64 | * @ns_ndirtyblks: Number of dirty data blocks | |
65 | * @ns_last_segment_lock: lock protecting fields for the latest segment | |
66 | * @ns_last_pseg: start block number of the latest segment | |
67 | * @ns_last_seq: sequence value of the latest segment | |
68 | * @ns_last_cno: checkpoint number of the latest segment | |
2c2e52fc | 69 | * @ns_prot_seq: least sequence number of segments which must not be reclaimed |
32502047 | 70 | * @ns_prev_seq: base sequence number used to decide if advance log cursor |
3fd3fe5a RK |
71 | * @ns_writer: log writer |
72 | * @ns_segctor_sem: semaphore protecting log write | |
65b4643d RK |
73 | * @ns_dat: DAT file inode |
74 | * @ns_cpfile: checkpoint file inode | |
75 | * @ns_sufile: segusage file inode | |
ba65ae47 RK |
76 | * @ns_cptree: rb-tree of all mounted checkpoints (nilfs_root) |
77 | * @ns_cptree_lock: lock protecting @ns_cptree | |
693dd321 RK |
78 | * @ns_dirty_files: list of dirty files |
79 | * @ns_inode_lock: lock protecting @ns_dirty_files | |
65b4643d | 80 | * @ns_gc_inodes: dummy inodes to keep live blocks |
9b1fc4e4 RK |
81 | * @ns_next_generation: next generation number for inodes |
82 | * @ns_next_gen_lock: lock protecting @ns_next_generation | |
3b2ce58b | 83 | * @ns_mount_opt: mount options |
574e6c31 RK |
84 | * @ns_resuid: uid for reserved blocks |
85 | * @ns_resgid: gid for reserved blocks | |
86 | * @ns_interval: checkpoint creation interval | |
87 | * @ns_watermark: watermark for the number of dirty buffers | |
65b4643d | 88 | * @ns_blocksize_bits: bit length of block size |
92c60cca | 89 | * @ns_blocksize: block size |
65b4643d RK |
90 | * @ns_nsegments: number of segments in filesystem |
91 | * @ns_blocks_per_segment: number of blocks per segment | |
92 | * @ns_r_segments_percentage: reserved segments percentage | |
93 | * @ns_nrsvsegs: number of reserved segments | |
94 | * @ns_first_data_block: block number of first data block | |
95 | * @ns_inode_size: size of on-disk inode | |
96 | * @ns_first_ino: first not-special inode number | |
97 | * @ns_crc_seed: seed value of CRC32 calculation | |
da7141fb VD |
98 | * @ns_dev_kobj: /sys/fs/<nilfs>/<device> |
99 | * @ns_dev_kobj_unregister: completion state | |
caa05d49 | 100 | * @ns_dev_subgroups: <device> subgroups pointer |
65b4643d RK |
101 | */ |
102 | struct the_nilfs { | |
103 | unsigned long ns_flags; | |
e2c7617a | 104 | int ns_flushed_device; |
65b4643d | 105 | |
6625689e | 106 | struct super_block *ns_sb; |
65b4643d | 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 | 118 | time_t ns_sbwtime; |
0c6c44cb RK |
119 | unsigned int ns_sbwcount; |
120 | unsigned int ns_sbsize; | |
121 | unsigned int ns_mount_state; | |
122 | unsigned int ns_sb_update_freq; | |
65b4643d RK |
123 | |
124 | /* | |
ad980c9a RK |
125 | * The following fields are updated by a writable FS-instance. |
126 | * These fields are protected by ns_segctor_sem outside load_nilfs(). | |
65b4643d RK |
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 | 148 | |
3fd3fe5a | 149 | struct nilfs_sc_info *ns_writer; |
65b4643d RK |
150 | struct rw_semaphore ns_segctor_sem; |
151 | ||
152 | /* | |
153 | * Following fields are lock free except for the period before | |
154 | * the_nilfs is initialized. | |
155 | */ | |
156 | struct inode *ns_dat; | |
157 | struct inode *ns_cpfile; | |
158 | struct inode *ns_sufile; | |
65b4643d | 159 | |
ba65ae47 RK |
160 | /* Checkpoint tree */ |
161 | struct rb_root ns_cptree; | |
162 | spinlock_t ns_cptree_lock; | |
163 | ||
693dd321 RK |
164 | /* Dirty inode list */ |
165 | struct list_head ns_dirty_files; | |
166 | spinlock_t ns_inode_lock; | |
167 | ||
263d90ce | 168 | /* GC inode list */ |
65b4643d | 169 | struct list_head ns_gc_inodes; |
65b4643d | 170 | |
9b1fc4e4 RK |
171 | /* Inode allocator */ |
172 | u32 ns_next_generation; | |
173 | spinlock_t ns_next_gen_lock; | |
174 | ||
3b2ce58b RK |
175 | /* Mount options */ |
176 | unsigned long ns_mount_opt; | |
177 | ||
574e6c31 RK |
178 | uid_t ns_resuid; |
179 | gid_t ns_resgid; | |
180 | unsigned long ns_interval; | |
181 | unsigned long ns_watermark; | |
182 | ||
65b4643d RK |
183 | /* Disk layout information (static) */ |
184 | unsigned int ns_blocksize_bits; | |
92c60cca | 185 | unsigned int ns_blocksize; |
65b4643d RK |
186 | unsigned long ns_nsegments; |
187 | unsigned long ns_blocks_per_segment; | |
188 | unsigned long ns_r_segments_percentage; | |
189 | unsigned long ns_nrsvsegs; | |
190 | unsigned long ns_first_data_block; | |
191 | int ns_inode_size; | |
192 | int ns_first_ino; | |
193 | u32 ns_crc_seed; | |
da7141fb VD |
194 | |
195 | /* /sys/fs/<nilfs>/<device> */ | |
196 | struct kobject ns_dev_kobj; | |
197 | struct completion ns_dev_kobj_unregister; | |
caa05d49 | 198 | struct nilfs_sysfs_dev_subgroups *ns_dev_subgroups; |
65b4643d RK |
199 | }; |
200 | ||
65b4643d RK |
201 | #define THE_NILFS_FNS(bit, name) \ |
202 | static inline void set_nilfs_##name(struct the_nilfs *nilfs) \ | |
203 | { \ | |
204 | set_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ | |
205 | } \ | |
206 | static inline void clear_nilfs_##name(struct the_nilfs *nilfs) \ | |
207 | { \ | |
208 | clear_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ | |
209 | } \ | |
210 | static inline int nilfs_##name(struct the_nilfs *nilfs) \ | |
211 | { \ | |
212 | return test_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ | |
213 | } | |
214 | ||
215 | THE_NILFS_FNS(INIT, init) | |
65b4643d | 216 | THE_NILFS_FNS(DISCONTINUED, discontinued) |
1cf58fa8 | 217 | THE_NILFS_FNS(GC_RUNNING, gc_running) |
e605f0a7 | 218 | THE_NILFS_FNS(SB_DIRTY, sb_dirty) |
65b4643d | 219 | |
3b2ce58b RK |
220 | /* |
221 | * Mount option operations | |
222 | */ | |
223 | #define nilfs_clear_opt(nilfs, opt) \ | |
80d65052 | 224 | ((nilfs)->ns_mount_opt &= ~NILFS_MOUNT_##opt) |
3b2ce58b | 225 | #define nilfs_set_opt(nilfs, opt) \ |
80d65052 | 226 | ((nilfs)->ns_mount_opt |= NILFS_MOUNT_##opt) |
3b2ce58b RK |
227 | #define nilfs_test_opt(nilfs, opt) ((nilfs)->ns_mount_opt & NILFS_MOUNT_##opt) |
228 | #define nilfs_write_opt(nilfs, mask, opt) \ | |
80d65052 | 229 | ((nilfs)->ns_mount_opt = \ |
3b2ce58b | 230 | (((nilfs)->ns_mount_opt & ~NILFS_MOUNT_##mask) | \ |
80d65052 | 231 | NILFS_MOUNT_##opt)) \ |
3b2ce58b | 232 | |
ba65ae47 RK |
233 | /** |
234 | * struct nilfs_root - nilfs root object | |
235 | * @cno: checkpoint number | |
236 | * @rb_node: red-black tree node | |
237 | * @count: refcount of this structure | |
238 | * @nilfs: nilfs object | |
239 | * @ifile: inode file | |
ba65ae47 | 240 | * @inodes_count: number of inodes |
f5974c8f | 241 | * @blocks_count: number of blocks |
a5a7332a VD |
242 | * @snapshot_kobj: /sys/fs/<nilfs>/<device>/mounted_snapshots/<snapshot> |
243 | * @snapshot_kobj_unregister: completion state for kernel object | |
ba65ae47 RK |
244 | */ |
245 | struct nilfs_root { | |
246 | __u64 cno; | |
247 | struct rb_node rb_node; | |
248 | ||
249 | atomic_t count; | |
250 | struct the_nilfs *nilfs; | |
251 | struct inode *ifile; | |
252 | ||
e5f7f848 VD |
253 | atomic64_t inodes_count; |
254 | atomic64_t blocks_count; | |
a5a7332a VD |
255 | |
256 | /* /sys/fs/<nilfs>/<device>/mounted_snapshots/<snapshot> */ | |
257 | struct kobject snapshot_kobj; | |
258 | struct completion snapshot_kobj_unregister; | |
ba65ae47 RK |
259 | }; |
260 | ||
261 | /* Special checkpoint number */ | |
262 | #define NILFS_CPTREE_CURRENT_CNO 0 | |
263 | ||
e339ad31 RK |
264 | /* Minimum interval of periodical update of superblocks (in seconds) */ |
265 | #define NILFS_SB_FREQ 10 | |
e339ad31 | 266 | |
79efdd94 JS |
267 | static inline int nilfs_sb_need_update(struct the_nilfs *nilfs) |
268 | { | |
269 | u64 t = get_seconds(); | |
4ad364ca | 270 | |
caa05d49 VD |
271 | return t < nilfs->ns_sbwtime || |
272 | t > nilfs->ns_sbwtime + nilfs->ns_sb_update_freq; | |
79efdd94 JS |
273 | } |
274 | ||
b2ac86e1 | 275 | static inline int nilfs_sb_will_flip(struct the_nilfs *nilfs) |
79efdd94 | 276 | { |
b2ac86e1 | 277 | int flip_bits = nilfs->ns_sbwcount & 0x0FL; |
4ad364ca | 278 | |
b2ac86e1 | 279 | return (flip_bits != 0x08 && flip_bits != 0x0F); |
79efdd94 JS |
280 | } |
281 | ||
65b4643d | 282 | void nilfs_set_last_segment(struct the_nilfs *, sector_t, u64, __u64); |
6625689e | 283 | struct the_nilfs *alloc_nilfs(struct super_block *sb); |
348fe8da | 284 | void destroy_nilfs(struct the_nilfs *nilfs); |
f7545144 RK |
285 | int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data); |
286 | int load_nilfs(struct the_nilfs *nilfs, struct super_block *sb); | |
4e33f9ea RK |
287 | unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs); |
288 | void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs); | |
e902ec99 | 289 | int nilfs_discard_segments(struct the_nilfs *, __u64 *, size_t); |
65b4643d | 290 | int nilfs_count_free_blocks(struct the_nilfs *, sector_t *); |
ba65ae47 RK |
291 | struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno); |
292 | struct nilfs_root *nilfs_find_or_create_root(struct the_nilfs *nilfs, | |
293 | __u64 cno); | |
294 | void nilfs_put_root(struct nilfs_root *root); | |
65b4643d | 295 | int nilfs_near_disk_full(struct the_nilfs *); |
e339ad31 RK |
296 | void nilfs_fall_back_super_block(struct the_nilfs *); |
297 | void nilfs_swap_super_block(struct the_nilfs *); | |
65b4643d RK |
298 | |
299 | ||
ba65ae47 RK |
300 | static inline void nilfs_get_root(struct nilfs_root *root) |
301 | { | |
302 | atomic_inc(&root->count); | |
303 | } | |
304 | ||
a057d2c0 RK |
305 | static inline int nilfs_valid_fs(struct the_nilfs *nilfs) |
306 | { | |
0c6c44cb | 307 | unsigned int valid_fs; |
a057d2c0 RK |
308 | |
309 | down_read(&nilfs->ns_sem); | |
310 | valid_fs = (nilfs->ns_mount_state & NILFS_VALID_FS); | |
311 | up_read(&nilfs->ns_sem); | |
312 | return valid_fs; | |
313 | } | |
314 | ||
65b4643d RK |
315 | static inline void |
316 | nilfs_get_segment_range(struct the_nilfs *nilfs, __u64 segnum, | |
317 | sector_t *seg_start, sector_t *seg_end) | |
318 | { | |
319 | *seg_start = (sector_t)nilfs->ns_blocks_per_segment * segnum; | |
320 | *seg_end = *seg_start + nilfs->ns_blocks_per_segment - 1; | |
321 | if (segnum == 0) | |
322 | *seg_start = nilfs->ns_first_data_block; | |
323 | } | |
324 | ||
325 | static inline sector_t | |
326 | nilfs_get_segment_start_blocknr(struct the_nilfs *nilfs, __u64 segnum) | |
327 | { | |
328 | return (segnum == 0) ? nilfs->ns_first_data_block : | |
329 | (sector_t)nilfs->ns_blocks_per_segment * segnum; | |
330 | } | |
331 | ||
332 | static inline __u64 | |
333 | nilfs_get_segnum_of_block(struct the_nilfs *nilfs, sector_t blocknr) | |
334 | { | |
335 | sector_t segnum = blocknr; | |
336 | ||
337 | sector_div(segnum, nilfs->ns_blocks_per_segment); | |
338 | return segnum; | |
339 | } | |
340 | ||
341 | static inline void | |
342 | nilfs_terminate_segment(struct the_nilfs *nilfs, sector_t seg_start, | |
343 | sector_t seg_end) | |
344 | { | |
345 | /* terminate the current full segment (used in case of I/O-error) */ | |
346 | nilfs->ns_pseg_offset = seg_end - seg_start + 1; | |
347 | } | |
348 | ||
349 | static inline void nilfs_shift_to_next_segment(struct the_nilfs *nilfs) | |
350 | { | |
351 | /* move forward with a full segment */ | |
352 | nilfs->ns_segnum = nilfs->ns_nextnum; | |
353 | nilfs->ns_pseg_offset = 0; | |
354 | nilfs->ns_seg_seq++; | |
355 | } | |
356 | ||
357 | static inline __u64 nilfs_last_cno(struct the_nilfs *nilfs) | |
358 | { | |
359 | __u64 cno; | |
360 | ||
361 | spin_lock(&nilfs->ns_last_segment_lock); | |
362 | cno = nilfs->ns_last_cno; | |
363 | spin_unlock(&nilfs->ns_last_segment_lock); | |
364 | return cno; | |
365 | } | |
366 | ||
cece5520 RK |
367 | static inline int nilfs_segment_is_active(struct the_nilfs *nilfs, __u64 n) |
368 | { | |
369 | return n == nilfs->ns_segnum || n == nilfs->ns_nextnum; | |
370 | } | |
371 | ||
e2c7617a AR |
372 | static inline int nilfs_flush_device(struct the_nilfs *nilfs) |
373 | { | |
374 | int err; | |
375 | ||
376 | if (!nilfs_test_opt(nilfs, BARRIER) || nilfs->ns_flushed_device) | |
377 | return 0; | |
378 | ||
379 | nilfs->ns_flushed_device = 1; | |
380 | /* | |
381 | * the store to ns_flushed_device must not be reordered after | |
382 | * blkdev_issue_flush(). | |
383 | */ | |
384 | smp_wmb(); | |
385 | ||
386 | err = blkdev_issue_flush(nilfs->ns_bdev, GFP_KERNEL, NULL); | |
387 | if (err != -EIO) | |
388 | err = 0; | |
389 | return err; | |
390 | } | |
391 | ||
65b4643d | 392 | #endif /* _THE_NILFS_H */ |