1 | /* SPDX-License-Identifier: GPL-2.0+ */ |
2 | /* |
3 | * the_nilfs shared structure. |
4 | * |
5 | * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. |
6 | * |
7 | * Written by Ryusuke Konishi. |
8 | * |
9 | */ |
10 | |
11 | #ifndef _THE_NILFS_H |
12 | #define _THE_NILFS_H |
13 | |
14 | #include <linux/types.h> |
15 | #include <linux/buffer_head.h> |
16 | #include <linux/rbtree.h> |
17 | #include <linux/fs.h> |
18 | #include <linux/blkdev.h> |
19 | #include <linux/backing-dev.h> |
20 | #include <linux/slab.h> |
21 | #include <linux/refcount.h> |
22 | |
23 | struct nilfs_sc_info; |
24 | struct nilfs_sysfs_dev_subgroups; |
25 | |
26 | /* the_nilfs struct */ |
27 | enum { |
28 | THE_NILFS_INIT = 0, /* Information from super_block is set */ |
29 | THE_NILFS_DISCONTINUED, /* 'next' pointer chain has broken */ |
30 | THE_NILFS_GC_RUNNING, /* gc process is running */ |
31 | THE_NILFS_SB_DIRTY, /* super block is dirty */ |
32 | THE_NILFS_PURGING, /* disposing dirty files for cleanup */ |
33 | }; |
34 | |
35 | /** |
36 | * struct the_nilfs - struct to supervise multiple nilfs mount points |
37 | * @ns_flags: flags |
38 | * @ns_flushed_device: flag indicating if all volatile data was flushed |
39 | * @ns_sb: back pointer to super block instance |
40 | * @ns_bdev: block device |
41 | * @ns_sem: semaphore for shared states |
42 | * @ns_snapshot_mount_mutex: mutex to protect snapshot mounts |
43 | * @ns_sbh: buffer heads of on-disk super blocks |
44 | * @ns_sbp: pointers to super block data |
45 | * @ns_sbwtime: previous write time of super block |
46 | * @ns_sbwcount: write count of super block |
47 | * @ns_sbsize: size of valid data in super block |
48 | * @ns_mount_state: file system state |
49 | * @ns_sb_update_freq: interval of periodical update of superblocks (in seconds) |
50 | * @ns_seg_seq: segment sequence counter |
51 | * @ns_segnum: index number of the latest full segment. |
52 | * @ns_nextnum: index number of the full segment index to be used next |
53 | * @ns_pseg_offset: offset of next partial segment in the current full segment |
54 | * @ns_cno: next checkpoint number |
55 | * @ns_ctime: write time of the last segment |
56 | * @ns_nongc_ctime: write time of the last segment not for cleaner operation |
57 | * @ns_ndirtyblks: Number of dirty data blocks |
58 | * @ns_last_segment_lock: lock protecting fields for the latest segment |
59 | * @ns_last_pseg: start block number of the latest segment |
60 | * @ns_last_seq: sequence value of the latest segment |
61 | * @ns_last_cno: checkpoint number of the latest segment |
62 | * @ns_prot_seq: least sequence number of segments which must not be reclaimed |
63 | * @ns_prev_seq: base sequence number used to decide if advance log cursor |
64 | * @ns_writer: log writer |
65 | * @ns_segctor_sem: semaphore protecting log write |
66 | * @ns_dat: DAT file inode |
67 | * @ns_cpfile: checkpoint file inode |
68 | * @ns_sufile: segusage file inode |
69 | * @ns_cptree: rb-tree of all mounted checkpoints (nilfs_root) |
70 | * @ns_cptree_lock: lock protecting @ns_cptree |
71 | * @ns_dirty_files: list of dirty files |
72 | * @ns_inode_lock: lock protecting @ns_dirty_files |
73 | * @ns_gc_inodes: dummy inodes to keep live blocks |
74 | * @ns_next_generation: next generation number for inodes |
75 | * @ns_next_gen_lock: lock protecting @ns_next_generation |
76 | * @ns_mount_opt: mount options |
77 | * @ns_resuid: uid for reserved blocks |
78 | * @ns_resgid: gid for reserved blocks |
79 | * @ns_interval: checkpoint creation interval |
80 | * @ns_watermark: watermark for the number of dirty buffers |
81 | * @ns_blocksize_bits: bit length of block size |
82 | * @ns_blocksize: block size |
83 | * @ns_nsegments: number of segments in filesystem |
84 | * @ns_blocks_per_segment: number of blocks per segment |
85 | * @ns_r_segments_percentage: reserved segments percentage |
86 | * @ns_nrsvsegs: number of reserved segments |
87 | * @ns_first_data_block: block number of first data block |
88 | * @ns_inode_size: size of on-disk inode |
89 | * @ns_first_ino: first not-special inode number |
90 | * @ns_crc_seed: seed value of CRC32 calculation |
91 | * @ns_dev_kobj: /sys/fs/<nilfs>/<device> |
92 | * @ns_dev_kobj_unregister: completion state |
93 | * @ns_dev_subgroups: <device> subgroups pointer |
94 | */ |
95 | struct the_nilfs { |
96 | unsigned long ns_flags; |
97 | int ns_flushed_device; |
98 | |
99 | struct super_block *ns_sb; |
100 | struct block_device *ns_bdev; |
101 | struct rw_semaphore ns_sem; |
102 | struct mutex ns_snapshot_mount_mutex; |
103 | |
104 | /* |
105 | * used for |
106 | * - loading the latest checkpoint exclusively. |
107 | * - allocating a new full segment. |
108 | */ |
109 | struct buffer_head *ns_sbh[2]; |
110 | struct nilfs_super_block *ns_sbp[2]; |
111 | time64_t ns_sbwtime; |
112 | unsigned int ns_sbwcount; |
113 | unsigned int ns_sbsize; |
114 | unsigned int ns_mount_state; |
115 | unsigned int ns_sb_update_freq; |
116 | |
117 | /* |
118 | * The following fields are updated by a writable FS-instance. |
119 | * These fields are protected by ns_segctor_sem outside load_nilfs(). |
120 | */ |
121 | u64 ns_seg_seq; |
122 | __u64 ns_segnum; |
123 | __u64 ns_nextnum; |
124 | unsigned long ns_pseg_offset; |
125 | __u64 ns_cno; |
126 | time64_t ns_ctime; |
127 | time64_t ns_nongc_ctime; |
128 | atomic_t ns_ndirtyblks; |
129 | |
130 | /* |
131 | * The following fields hold information on the latest partial segment |
132 | * written to disk with a super root. These fields are protected by |
133 | * ns_last_segment_lock. |
134 | */ |
135 | spinlock_t ns_last_segment_lock; |
136 | sector_t ns_last_pseg; |
137 | u64 ns_last_seq; |
138 | __u64 ns_last_cno; |
139 | u64 ns_prot_seq; |
140 | u64 ns_prev_seq; |
141 | |
142 | struct nilfs_sc_info *ns_writer; |
143 | struct rw_semaphore ns_segctor_sem; |
144 | |
145 | /* |
146 | * Following fields are lock free except for the period before |
147 | * the_nilfs is initialized. |
148 | */ |
149 | struct inode *ns_dat; |
150 | struct inode *ns_cpfile; |
151 | struct inode *ns_sufile; |
152 | |
153 | /* Checkpoint tree */ |
154 | struct rb_root ns_cptree; |
155 | spinlock_t ns_cptree_lock; |
156 | |
157 | /* Dirty inode list */ |
158 | struct list_head ns_dirty_files; |
159 | spinlock_t ns_inode_lock; |
160 | |
161 | /* GC inode list */ |
162 | struct list_head ns_gc_inodes; |
163 | |
164 | /* Inode allocator */ |
165 | u32 ns_next_generation; |
166 | spinlock_t ns_next_gen_lock; |
167 | |
168 | /* Mount options */ |
169 | unsigned long ns_mount_opt; |
170 | |
171 | uid_t ns_resuid; |
172 | gid_t ns_resgid; |
173 | unsigned long ns_interval; |
174 | unsigned long ns_watermark; |
175 | |
176 | /* Disk layout information (static) */ |
177 | unsigned int ns_blocksize_bits; |
178 | unsigned int ns_blocksize; |
179 | unsigned long ns_nsegments; |
180 | unsigned long ns_blocks_per_segment; |
181 | unsigned long ns_r_segments_percentage; |
182 | unsigned long ns_nrsvsegs; |
183 | unsigned long ns_first_data_block; |
184 | int ns_inode_size; |
185 | int ns_first_ino; |
186 | u32 ns_crc_seed; |
187 | |
188 | /* /sys/fs/<nilfs>/<device> */ |
189 | struct kobject ns_dev_kobj; |
190 | struct completion ns_dev_kobj_unregister; |
191 | struct nilfs_sysfs_dev_subgroups *ns_dev_subgroups; |
192 | }; |
193 | |
194 | #define THE_NILFS_FNS(bit, name) \ |
195 | static inline void set_nilfs_##name(struct the_nilfs *nilfs) \ |
196 | { \ |
197 | set_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ |
198 | } \ |
199 | static inline void clear_nilfs_##name(struct the_nilfs *nilfs) \ |
200 | { \ |
201 | clear_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ |
202 | } \ |
203 | static inline int nilfs_##name(struct the_nilfs *nilfs) \ |
204 | { \ |
205 | return test_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ |
206 | } |
207 | |
208 | THE_NILFS_FNS(INIT, init) |
209 | THE_NILFS_FNS(DISCONTINUED, discontinued) |
210 | THE_NILFS_FNS(GC_RUNNING, gc_running) |
211 | THE_NILFS_FNS(SB_DIRTY, sb_dirty) |
212 | THE_NILFS_FNS(PURGING, purging) |
213 | |
214 | /* |
215 | * Mount option operations |
216 | */ |
217 | #define nilfs_clear_opt(nilfs, opt) \ |
218 | ((nilfs)->ns_mount_opt &= ~NILFS_MOUNT_##opt) |
219 | #define nilfs_set_opt(nilfs, opt) \ |
220 | ((nilfs)->ns_mount_opt |= NILFS_MOUNT_##opt) |
221 | #define nilfs_test_opt(nilfs, opt) ((nilfs)->ns_mount_opt & NILFS_MOUNT_##opt) |
222 | #define nilfs_write_opt(nilfs, mask, opt) \ |
223 | ((nilfs)->ns_mount_opt = \ |
224 | (((nilfs)->ns_mount_opt & ~NILFS_MOUNT_##mask) | \ |
225 | NILFS_MOUNT_##opt)) \ |
226 | |
227 | /** |
228 | * struct nilfs_root - nilfs root object |
229 | * @cno: checkpoint number |
230 | * @rb_node: red-black tree node |
231 | * @count: refcount of this structure |
232 | * @nilfs: nilfs object |
233 | * @ifile: inode file |
234 | * @inodes_count: number of inodes |
235 | * @blocks_count: number of blocks |
236 | * @snapshot_kobj: /sys/fs/<nilfs>/<device>/mounted_snapshots/<snapshot> |
237 | * @snapshot_kobj_unregister: completion state for kernel object |
238 | */ |
239 | struct nilfs_root { |
240 | __u64 cno; |
241 | struct rb_node rb_node; |
242 | |
243 | refcount_t count; |
244 | struct the_nilfs *nilfs; |
245 | struct inode *ifile; |
246 | |
247 | atomic64_t inodes_count; |
248 | atomic64_t blocks_count; |
249 | |
250 | /* /sys/fs/<nilfs>/<device>/mounted_snapshots/<snapshot> */ |
251 | struct kobject snapshot_kobj; |
252 | struct completion snapshot_kobj_unregister; |
253 | }; |
254 | |
255 | /* Special checkpoint number */ |
256 | #define NILFS_CPTREE_CURRENT_CNO 0 |
257 | |
258 | /* Minimum interval of periodical update of superblocks (in seconds) */ |
259 | #define NILFS_SB_FREQ 10 |
260 | |
261 | static inline int nilfs_sb_need_update(struct the_nilfs *nilfs) |
262 | { |
263 | u64 t = ktime_get_real_seconds(); |
264 | |
265 | return t < nilfs->ns_sbwtime || |
266 | t > nilfs->ns_sbwtime + nilfs->ns_sb_update_freq; |
267 | } |
268 | |
269 | static inline int nilfs_sb_will_flip(struct the_nilfs *nilfs) |
270 | { |
271 | int flip_bits = nilfs->ns_sbwcount & 0x0FL; |
272 | |
273 | return (flip_bits != 0x08 && flip_bits != 0x0F); |
274 | } |
275 | |
276 | void nilfs_set_last_segment(struct the_nilfs *, sector_t, u64, __u64); |
277 | struct the_nilfs *alloc_nilfs(struct super_block *sb); |
278 | void destroy_nilfs(struct the_nilfs *nilfs); |
279 | int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data); |
280 | int load_nilfs(struct the_nilfs *nilfs, struct super_block *sb); |
281 | unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs); |
282 | void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs); |
283 | int nilfs_discard_segments(struct the_nilfs *, __u64 *, size_t); |
284 | int nilfs_count_free_blocks(struct the_nilfs *, sector_t *); |
285 | struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno); |
286 | struct nilfs_root *nilfs_find_or_create_root(struct the_nilfs *nilfs, |
287 | __u64 cno); |
288 | void nilfs_put_root(struct nilfs_root *root); |
289 | int nilfs_near_disk_full(struct the_nilfs *); |
290 | void nilfs_fall_back_super_block(struct the_nilfs *); |
291 | void nilfs_swap_super_block(struct the_nilfs *); |
292 | |
293 | |
294 | static inline void nilfs_get_root(struct nilfs_root *root) |
295 | { |
296 | refcount_inc(r: &root->count); |
297 | } |
298 | |
299 | static inline int nilfs_valid_fs(struct the_nilfs *nilfs) |
300 | { |
301 | unsigned int valid_fs; |
302 | |
303 | down_read(sem: &nilfs->ns_sem); |
304 | valid_fs = (nilfs->ns_mount_state & NILFS_VALID_FS); |
305 | up_read(sem: &nilfs->ns_sem); |
306 | return valid_fs; |
307 | } |
308 | |
309 | static inline void |
310 | nilfs_get_segment_range(struct the_nilfs *nilfs, __u64 segnum, |
311 | sector_t *seg_start, sector_t *seg_end) |
312 | { |
313 | *seg_start = (sector_t)nilfs->ns_blocks_per_segment * segnum; |
314 | *seg_end = *seg_start + nilfs->ns_blocks_per_segment - 1; |
315 | if (segnum == 0) |
316 | *seg_start = nilfs->ns_first_data_block; |
317 | } |
318 | |
319 | static inline sector_t |
320 | nilfs_get_segment_start_blocknr(struct the_nilfs *nilfs, __u64 segnum) |
321 | { |
322 | return (segnum == 0) ? nilfs->ns_first_data_block : |
323 | (sector_t)nilfs->ns_blocks_per_segment * segnum; |
324 | } |
325 | |
326 | static inline __u64 |
327 | nilfs_get_segnum_of_block(struct the_nilfs *nilfs, sector_t blocknr) |
328 | { |
329 | sector_t segnum = blocknr; |
330 | |
331 | sector_div(segnum, nilfs->ns_blocks_per_segment); |
332 | return segnum; |
333 | } |
334 | |
335 | static inline void |
336 | nilfs_terminate_segment(struct the_nilfs *nilfs, sector_t seg_start, |
337 | sector_t seg_end) |
338 | { |
339 | /* terminate the current full segment (used in case of I/O-error) */ |
340 | nilfs->ns_pseg_offset = seg_end - seg_start + 1; |
341 | } |
342 | |
343 | static inline void nilfs_shift_to_next_segment(struct the_nilfs *nilfs) |
344 | { |
345 | /* move forward with a full segment */ |
346 | nilfs->ns_segnum = nilfs->ns_nextnum; |
347 | nilfs->ns_pseg_offset = 0; |
348 | nilfs->ns_seg_seq++; |
349 | } |
350 | |
351 | static inline __u64 nilfs_last_cno(struct the_nilfs *nilfs) |
352 | { |
353 | __u64 cno; |
354 | |
355 | spin_lock(lock: &nilfs->ns_last_segment_lock); |
356 | cno = nilfs->ns_last_cno; |
357 | spin_unlock(lock: &nilfs->ns_last_segment_lock); |
358 | return cno; |
359 | } |
360 | |
361 | static inline int nilfs_segment_is_active(struct the_nilfs *nilfs, __u64 n) |
362 | { |
363 | return n == nilfs->ns_segnum || n == nilfs->ns_nextnum; |
364 | } |
365 | |
366 | static inline int nilfs_flush_device(struct the_nilfs *nilfs) |
367 | { |
368 | int err; |
369 | |
370 | if (!nilfs_test_opt(nilfs, BARRIER) || nilfs->ns_flushed_device) |
371 | return 0; |
372 | |
373 | nilfs->ns_flushed_device = 1; |
374 | /* |
375 | * the store to ns_flushed_device must not be reordered after |
376 | * blkdev_issue_flush(). |
377 | */ |
378 | smp_wmb(); |
379 | |
380 | err = blkdev_issue_flush(bdev: nilfs->ns_bdev); |
381 | if (err != -EIO) |
382 | err = 0; |
383 | return err; |
384 | } |
385 | |
386 | #endif /* _THE_NILFS_H */ |
387 | |