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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 |
65b4643d | 46 | * @ns_bdev: block device |
65b4643d | 47 | * @ns_sem: semaphore for shared states |
572d8b39 | 48 | * @ns_snapshot_mount_mutex: mutex to protect snapshot mounts |
e339ad31 RK |
49 | * @ns_sbh: buffer heads of on-disk super blocks |
50 | * @ns_sbp: pointers to super block data | |
b2ac86e1 JS |
51 | * @ns_sbwtime: previous write time of super block |
52 | * @ns_sbwcount: write count of super block | |
e339ad31 | 53 | * @ns_sbsize: size of valid data in super block |
6b0f3393 | 54 | * @ns_mount_state: file system state |
caa05d49 | 55 | * @ns_sb_update_freq: interval of periodical update of superblocks (in seconds) |
65b4643d RK |
56 | * @ns_seg_seq: segment sequence counter |
57 | * @ns_segnum: index number of the latest full segment. | |
58 | * @ns_nextnum: index number of the full segment index to be used next | |
59 | * @ns_pseg_offset: offset of next partial segment in the current full segment | |
60 | * @ns_cno: next checkpoint number | |
61 | * @ns_ctime: write time of the last segment | |
62 | * @ns_nongc_ctime: write time of the last segment not for cleaner operation | |
63 | * @ns_ndirtyblks: Number of dirty data blocks | |
64 | * @ns_last_segment_lock: lock protecting fields for the latest segment | |
65 | * @ns_last_pseg: start block number of the latest segment | |
66 | * @ns_last_seq: sequence value of the latest segment | |
67 | * @ns_last_cno: checkpoint number of the latest segment | |
2c2e52fc | 68 | * @ns_prot_seq: least sequence number of segments which must not be reclaimed |
32502047 | 69 | * @ns_prev_seq: base sequence number used to decide if advance log cursor |
3fd3fe5a RK |
70 | * @ns_writer: log writer |
71 | * @ns_segctor_sem: semaphore protecting log write | |
65b4643d RK |
72 | * @ns_dat: DAT file inode |
73 | * @ns_cpfile: checkpoint file inode | |
74 | * @ns_sufile: segusage file inode | |
ba65ae47 RK |
75 | * @ns_cptree: rb-tree of all mounted checkpoints (nilfs_root) |
76 | * @ns_cptree_lock: lock protecting @ns_cptree | |
693dd321 RK |
77 | * @ns_dirty_files: list of dirty files |
78 | * @ns_inode_lock: lock protecting @ns_dirty_files | |
65b4643d | 79 | * @ns_gc_inodes: dummy inodes to keep live blocks |
9b1fc4e4 RK |
80 | * @ns_next_generation: next generation number for inodes |
81 | * @ns_next_gen_lock: lock protecting @ns_next_generation | |
3b2ce58b | 82 | * @ns_mount_opt: mount options |
574e6c31 RK |
83 | * @ns_resuid: uid for reserved blocks |
84 | * @ns_resgid: gid for reserved blocks | |
85 | * @ns_interval: checkpoint creation interval | |
86 | * @ns_watermark: watermark for the number of dirty buffers | |
65b4643d | 87 | * @ns_blocksize_bits: bit length of block size |
92c60cca | 88 | * @ns_blocksize: block size |
65b4643d RK |
89 | * @ns_nsegments: number of segments in filesystem |
90 | * @ns_blocks_per_segment: number of blocks per segment | |
91 | * @ns_r_segments_percentage: reserved segments percentage | |
92 | * @ns_nrsvsegs: number of reserved segments | |
93 | * @ns_first_data_block: block number of first data block | |
94 | * @ns_inode_size: size of on-disk inode | |
95 | * @ns_first_ino: first not-special inode number | |
96 | * @ns_crc_seed: seed value of CRC32 calculation | |
da7141fb VD |
97 | * @ns_dev_kobj: /sys/fs/<nilfs>/<device> |
98 | * @ns_dev_kobj_unregister: completion state | |
caa05d49 | 99 | * @ns_dev_subgroups: <device> subgroups pointer |
65b4643d RK |
100 | */ |
101 | struct the_nilfs { | |
102 | unsigned long ns_flags; | |
e2c7617a | 103 | int ns_flushed_device; |
65b4643d RK |
104 | |
105 | struct block_device *ns_bdev; | |
65b4643d | 106 | struct rw_semaphore ns_sem; |
572d8b39 | 107 | struct mutex ns_snapshot_mount_mutex; |
65b4643d RK |
108 | |
109 | /* | |
110 | * used for | |
111 | * - loading the latest checkpoint exclusively. | |
112 | * - allocating a new full segment. | |
65b4643d | 113 | */ |
e339ad31 RK |
114 | struct buffer_head *ns_sbh[2]; |
115 | struct nilfs_super_block *ns_sbp[2]; | |
b2ac86e1 | 116 | time_t ns_sbwtime; |
0c6c44cb RK |
117 | unsigned int ns_sbwcount; |
118 | unsigned int ns_sbsize; | |
119 | unsigned int ns_mount_state; | |
120 | unsigned int ns_sb_update_freq; | |
65b4643d RK |
121 | |
122 | /* | |
123 | * Following fields are dedicated to a writable FS-instance. | |
124 | * Except for the period seeking checkpoint, code outside the segment | |
47420c79 RK |
125 | * constructor must lock a segment semaphore while accessing these |
126 | * fields. | |
65b4643d RK |
127 | * The writable FS-instance is sole during a lifetime of the_nilfs. |
128 | */ | |
129 | u64 ns_seg_seq; | |
130 | __u64 ns_segnum; | |
131 | __u64 ns_nextnum; | |
132 | unsigned long ns_pseg_offset; | |
133 | __u64 ns_cno; | |
134 | time_t ns_ctime; | |
135 | time_t ns_nongc_ctime; | |
136 | atomic_t ns_ndirtyblks; | |
137 | ||
138 | /* | |
139 | * The following fields hold information on the latest partial segment | |
140 | * written to disk with a super root. These fields are protected by | |
141 | * ns_last_segment_lock. | |
142 | */ | |
143 | spinlock_t ns_last_segment_lock; | |
144 | sector_t ns_last_pseg; | |
145 | u64 ns_last_seq; | |
146 | __u64 ns_last_cno; | |
2c2e52fc | 147 | u64 ns_prot_seq; |
32502047 | 148 | u64 ns_prev_seq; |
65b4643d | 149 | |
3fd3fe5a | 150 | struct nilfs_sc_info *ns_writer; |
65b4643d RK |
151 | struct rw_semaphore ns_segctor_sem; |
152 | ||
153 | /* | |
154 | * Following fields are lock free except for the period before | |
155 | * the_nilfs is initialized. | |
156 | */ | |
157 | struct inode *ns_dat; | |
158 | struct inode *ns_cpfile; | |
159 | struct inode *ns_sufile; | |
65b4643d | 160 | |
ba65ae47 RK |
161 | /* Checkpoint tree */ |
162 | struct rb_root ns_cptree; | |
163 | spinlock_t ns_cptree_lock; | |
164 | ||
693dd321 RK |
165 | /* Dirty inode list */ |
166 | struct list_head ns_dirty_files; | |
167 | spinlock_t ns_inode_lock; | |
168 | ||
263d90ce | 169 | /* GC inode list */ |
65b4643d | 170 | struct list_head ns_gc_inodes; |
65b4643d | 171 | |
9b1fc4e4 RK |
172 | /* Inode allocator */ |
173 | u32 ns_next_generation; | |
174 | spinlock_t ns_next_gen_lock; | |
175 | ||
3b2ce58b RK |
176 | /* Mount options */ |
177 | unsigned long ns_mount_opt; | |
178 | ||
574e6c31 RK |
179 | uid_t ns_resuid; |
180 | gid_t ns_resgid; | |
181 | unsigned long ns_interval; | |
182 | unsigned long ns_watermark; | |
183 | ||
65b4643d RK |
184 | /* Disk layout information (static) */ |
185 | unsigned int ns_blocksize_bits; | |
92c60cca | 186 | unsigned int ns_blocksize; |
65b4643d RK |
187 | unsigned long ns_nsegments; |
188 | unsigned long ns_blocks_per_segment; | |
189 | unsigned long ns_r_segments_percentage; | |
190 | unsigned long ns_nrsvsegs; | |
191 | unsigned long ns_first_data_block; | |
192 | int ns_inode_size; | |
193 | int ns_first_ino; | |
194 | u32 ns_crc_seed; | |
da7141fb VD |
195 | |
196 | /* /sys/fs/<nilfs>/<device> */ | |
197 | struct kobject ns_dev_kobj; | |
198 | struct completion ns_dev_kobj_unregister; | |
caa05d49 | 199 | struct nilfs_sysfs_dev_subgroups *ns_dev_subgroups; |
65b4643d RK |
200 | }; |
201 | ||
65b4643d RK |
202 | #define THE_NILFS_FNS(bit, name) \ |
203 | static inline void set_nilfs_##name(struct the_nilfs *nilfs) \ | |
204 | { \ | |
205 | set_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ | |
206 | } \ | |
207 | static inline void clear_nilfs_##name(struct the_nilfs *nilfs) \ | |
208 | { \ | |
209 | clear_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ | |
210 | } \ | |
211 | static inline int nilfs_##name(struct the_nilfs *nilfs) \ | |
212 | { \ | |
213 | return test_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ | |
214 | } | |
215 | ||
216 | THE_NILFS_FNS(INIT, init) | |
65b4643d | 217 | THE_NILFS_FNS(DISCONTINUED, discontinued) |
1cf58fa8 | 218 | THE_NILFS_FNS(GC_RUNNING, gc_running) |
e605f0a7 | 219 | THE_NILFS_FNS(SB_DIRTY, sb_dirty) |
65b4643d | 220 | |
3b2ce58b RK |
221 | /* |
222 | * Mount option operations | |
223 | */ | |
224 | #define nilfs_clear_opt(nilfs, opt) \ | |
80d65052 | 225 | ((nilfs)->ns_mount_opt &= ~NILFS_MOUNT_##opt) |
3b2ce58b | 226 | #define nilfs_set_opt(nilfs, opt) \ |
80d65052 | 227 | ((nilfs)->ns_mount_opt |= NILFS_MOUNT_##opt) |
3b2ce58b RK |
228 | #define nilfs_test_opt(nilfs, opt) ((nilfs)->ns_mount_opt & NILFS_MOUNT_##opt) |
229 | #define nilfs_write_opt(nilfs, mask, opt) \ | |
80d65052 | 230 | ((nilfs)->ns_mount_opt = \ |
3b2ce58b | 231 | (((nilfs)->ns_mount_opt & ~NILFS_MOUNT_##mask) | \ |
80d65052 | 232 | NILFS_MOUNT_##opt)) \ |
3b2ce58b | 233 | |
ba65ae47 RK |
234 | /** |
235 | * struct nilfs_root - nilfs root object | |
236 | * @cno: checkpoint number | |
237 | * @rb_node: red-black tree node | |
238 | * @count: refcount of this structure | |
239 | * @nilfs: nilfs object | |
240 | * @ifile: inode file | |
ba65ae47 | 241 | * @inodes_count: number of inodes |
f5974c8f | 242 | * @blocks_count: number of blocks |
a5a7332a VD |
243 | * @snapshot_kobj: /sys/fs/<nilfs>/<device>/mounted_snapshots/<snapshot> |
244 | * @snapshot_kobj_unregister: completion state for kernel object | |
ba65ae47 RK |
245 | */ |
246 | struct nilfs_root { | |
247 | __u64 cno; | |
248 | struct rb_node rb_node; | |
249 | ||
250 | atomic_t count; | |
251 | struct the_nilfs *nilfs; | |
252 | struct inode *ifile; | |
253 | ||
e5f7f848 VD |
254 | atomic64_t inodes_count; |
255 | atomic64_t blocks_count; | |
a5a7332a VD |
256 | |
257 | /* /sys/fs/<nilfs>/<device>/mounted_snapshots/<snapshot> */ | |
258 | struct kobject snapshot_kobj; | |
259 | struct completion snapshot_kobj_unregister; | |
ba65ae47 RK |
260 | }; |
261 | ||
262 | /* Special checkpoint number */ | |
263 | #define NILFS_CPTREE_CURRENT_CNO 0 | |
264 | ||
e339ad31 RK |
265 | /* Minimum interval of periodical update of superblocks (in seconds) */ |
266 | #define NILFS_SB_FREQ 10 | |
e339ad31 | 267 | |
79efdd94 JS |
268 | static inline int nilfs_sb_need_update(struct the_nilfs *nilfs) |
269 | { | |
270 | u64 t = get_seconds(); | |
4ad364ca | 271 | |
caa05d49 VD |
272 | return t < nilfs->ns_sbwtime || |
273 | t > nilfs->ns_sbwtime + nilfs->ns_sb_update_freq; | |
79efdd94 JS |
274 | } |
275 | ||
b2ac86e1 | 276 | static inline int nilfs_sb_will_flip(struct the_nilfs *nilfs) |
79efdd94 | 277 | { |
b2ac86e1 | 278 | int flip_bits = nilfs->ns_sbwcount & 0x0FL; |
4ad364ca | 279 | |
b2ac86e1 | 280 | return (flip_bits != 0x08 && flip_bits != 0x0F); |
79efdd94 JS |
281 | } |
282 | ||
65b4643d | 283 | void nilfs_set_last_segment(struct the_nilfs *, sector_t, u64, __u64); |
348fe8da RK |
284 | struct the_nilfs *alloc_nilfs(struct block_device *bdev); |
285 | void destroy_nilfs(struct the_nilfs *nilfs); | |
f7545144 RK |
286 | int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data); |
287 | int load_nilfs(struct the_nilfs *nilfs, struct super_block *sb); | |
4e33f9ea RK |
288 | unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs); |
289 | void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs); | |
e902ec99 | 290 | int nilfs_discard_segments(struct the_nilfs *, __u64 *, size_t); |
65b4643d | 291 | int nilfs_count_free_blocks(struct the_nilfs *, sector_t *); |
ba65ae47 RK |
292 | struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno); |
293 | struct nilfs_root *nilfs_find_or_create_root(struct the_nilfs *nilfs, | |
294 | __u64 cno); | |
295 | void nilfs_put_root(struct nilfs_root *root); | |
65b4643d | 296 | int nilfs_near_disk_full(struct the_nilfs *); |
e339ad31 RK |
297 | void nilfs_fall_back_super_block(struct the_nilfs *); |
298 | void nilfs_swap_super_block(struct the_nilfs *); | |
65b4643d RK |
299 | |
300 | ||
ba65ae47 RK |
301 | static inline void nilfs_get_root(struct nilfs_root *root) |
302 | { | |
303 | atomic_inc(&root->count); | |
304 | } | |
305 | ||
a057d2c0 RK |
306 | static inline int nilfs_valid_fs(struct the_nilfs *nilfs) |
307 | { | |
0c6c44cb | 308 | unsigned int valid_fs; |
a057d2c0 RK |
309 | |
310 | down_read(&nilfs->ns_sem); | |
311 | valid_fs = (nilfs->ns_mount_state & NILFS_VALID_FS); | |
312 | up_read(&nilfs->ns_sem); | |
313 | return valid_fs; | |
314 | } | |
315 | ||
65b4643d RK |
316 | static inline void |
317 | nilfs_get_segment_range(struct the_nilfs *nilfs, __u64 segnum, | |
318 | sector_t *seg_start, sector_t *seg_end) | |
319 | { | |
320 | *seg_start = (sector_t)nilfs->ns_blocks_per_segment * segnum; | |
321 | *seg_end = *seg_start + nilfs->ns_blocks_per_segment - 1; | |
322 | if (segnum == 0) | |
323 | *seg_start = nilfs->ns_first_data_block; | |
324 | } | |
325 | ||
326 | static inline sector_t | |
327 | nilfs_get_segment_start_blocknr(struct the_nilfs *nilfs, __u64 segnum) | |
328 | { | |
329 | return (segnum == 0) ? nilfs->ns_first_data_block : | |
330 | (sector_t)nilfs->ns_blocks_per_segment * segnum; | |
331 | } | |
332 | ||
333 | static inline __u64 | |
334 | nilfs_get_segnum_of_block(struct the_nilfs *nilfs, sector_t blocknr) | |
335 | { | |
336 | sector_t segnum = blocknr; | |
337 | ||
338 | sector_div(segnum, nilfs->ns_blocks_per_segment); | |
339 | return segnum; | |
340 | } | |
341 | ||
342 | static inline void | |
343 | nilfs_terminate_segment(struct the_nilfs *nilfs, sector_t seg_start, | |
344 | sector_t seg_end) | |
345 | { | |
346 | /* terminate the current full segment (used in case of I/O-error) */ | |
347 | nilfs->ns_pseg_offset = seg_end - seg_start + 1; | |
348 | } | |
349 | ||
350 | static inline void nilfs_shift_to_next_segment(struct the_nilfs *nilfs) | |
351 | { | |
352 | /* move forward with a full segment */ | |
353 | nilfs->ns_segnum = nilfs->ns_nextnum; | |
354 | nilfs->ns_pseg_offset = 0; | |
355 | nilfs->ns_seg_seq++; | |
356 | } | |
357 | ||
358 | static inline __u64 nilfs_last_cno(struct the_nilfs *nilfs) | |
359 | { | |
360 | __u64 cno; | |
361 | ||
362 | spin_lock(&nilfs->ns_last_segment_lock); | |
363 | cno = nilfs->ns_last_cno; | |
364 | spin_unlock(&nilfs->ns_last_segment_lock); | |
365 | return cno; | |
366 | } | |
367 | ||
cece5520 RK |
368 | static inline int nilfs_segment_is_active(struct the_nilfs *nilfs, __u64 n) |
369 | { | |
370 | return n == nilfs->ns_segnum || n == nilfs->ns_nextnum; | |
371 | } | |
372 | ||
e2c7617a AR |
373 | static inline int nilfs_flush_device(struct the_nilfs *nilfs) |
374 | { | |
375 | int err; | |
376 | ||
377 | if (!nilfs_test_opt(nilfs, BARRIER) || nilfs->ns_flushed_device) | |
378 | return 0; | |
379 | ||
380 | nilfs->ns_flushed_device = 1; | |
381 | /* | |
382 | * the store to ns_flushed_device must not be reordered after | |
383 | * blkdev_issue_flush(). | |
384 | */ | |
385 | smp_wmb(); | |
386 | ||
387 | err = blkdev_issue_flush(nilfs->ns_bdev, GFP_KERNEL, NULL); | |
388 | if (err != -EIO) | |
389 | err = 0; | |
390 | return err; | |
391 | } | |
392 | ||
65b4643d | 393 | #endif /* _THE_NILFS_H */ |