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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 RK |
35 | struct nilfs_sc_info; |
36 | ||
65b4643d RK |
37 | /* the_nilfs struct */ |
38 | enum { | |
39 | THE_NILFS_INIT = 0, /* Information from super_block is set */ | |
65b4643d | 40 | THE_NILFS_DISCONTINUED, /* 'next' pointer chain has broken */ |
1cf58fa8 | 41 | THE_NILFS_GC_RUNNING, /* gc process is running */ |
e605f0a7 | 42 | THE_NILFS_SB_DIRTY, /* super block is dirty */ |
65b4643d RK |
43 | }; |
44 | ||
45 | /** | |
46 | * struct the_nilfs - struct to supervise multiple nilfs mount points | |
47 | * @ns_flags: flags | |
65b4643d | 48 | * @ns_bdev: block device |
65b4643d | 49 | * @ns_sem: semaphore for shared states |
572d8b39 | 50 | * @ns_snapshot_mount_mutex: mutex to protect snapshot mounts |
e339ad31 RK |
51 | * @ns_sbh: buffer heads of on-disk super blocks |
52 | * @ns_sbp: pointers to super block data | |
b2ac86e1 JS |
53 | * @ns_sbwtime: previous write time of super block |
54 | * @ns_sbwcount: write count of super block | |
e339ad31 | 55 | * @ns_sbsize: size of valid data in super block |
6b0f3393 | 56 | * @ns_mount_state: file system state |
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 | |
98 | */ | |
99 | struct the_nilfs { | |
100 | unsigned long ns_flags; | |
65b4643d RK |
101 | |
102 | struct block_device *ns_bdev; | |
65b4643d | 103 | struct rw_semaphore ns_sem; |
572d8b39 | 104 | struct mutex ns_snapshot_mount_mutex; |
65b4643d RK |
105 | |
106 | /* | |
107 | * used for | |
108 | * - loading the latest checkpoint exclusively. | |
109 | * - allocating a new full segment. | |
65b4643d | 110 | */ |
e339ad31 RK |
111 | struct buffer_head *ns_sbh[2]; |
112 | struct nilfs_super_block *ns_sbp[2]; | |
b2ac86e1 JS |
113 | time_t ns_sbwtime; |
114 | unsigned ns_sbwcount; | |
e339ad31 | 115 | unsigned ns_sbsize; |
65b4643d | 116 | unsigned ns_mount_state; |
65b4643d RK |
117 | |
118 | /* | |
119 | * Following fields are dedicated to a writable FS-instance. | |
120 | * Except for the period seeking checkpoint, code outside the segment | |
47420c79 RK |
121 | * constructor must lock a segment semaphore while accessing these |
122 | * fields. | |
65b4643d RK |
123 | * The writable FS-instance is sole during a lifetime of the_nilfs. |
124 | */ | |
125 | u64 ns_seg_seq; | |
126 | __u64 ns_segnum; | |
127 | __u64 ns_nextnum; | |
128 | unsigned long ns_pseg_offset; | |
129 | __u64 ns_cno; | |
130 | time_t ns_ctime; | |
131 | time_t ns_nongc_ctime; | |
132 | atomic_t ns_ndirtyblks; | |
133 | ||
134 | /* | |
135 | * The following fields hold information on the latest partial segment | |
136 | * written to disk with a super root. These fields are protected by | |
137 | * ns_last_segment_lock. | |
138 | */ | |
139 | spinlock_t ns_last_segment_lock; | |
140 | sector_t ns_last_pseg; | |
141 | u64 ns_last_seq; | |
142 | __u64 ns_last_cno; | |
2c2e52fc | 143 | u64 ns_prot_seq; |
32502047 | 144 | u64 ns_prev_seq; |
65b4643d | 145 | |
3fd3fe5a | 146 | struct nilfs_sc_info *ns_writer; |
65b4643d RK |
147 | struct rw_semaphore ns_segctor_sem; |
148 | ||
149 | /* | |
150 | * Following fields are lock free except for the period before | |
151 | * the_nilfs is initialized. | |
152 | */ | |
153 | struct inode *ns_dat; | |
154 | struct inode *ns_cpfile; | |
155 | struct inode *ns_sufile; | |
65b4643d | 156 | |
ba65ae47 RK |
157 | /* Checkpoint tree */ |
158 | struct rb_root ns_cptree; | |
159 | spinlock_t ns_cptree_lock; | |
160 | ||
693dd321 RK |
161 | /* Dirty inode list */ |
162 | struct list_head ns_dirty_files; | |
163 | spinlock_t ns_inode_lock; | |
164 | ||
263d90ce | 165 | /* GC inode list */ |
65b4643d | 166 | struct list_head ns_gc_inodes; |
65b4643d | 167 | |
9b1fc4e4 RK |
168 | /* Inode allocator */ |
169 | u32 ns_next_generation; | |
170 | spinlock_t ns_next_gen_lock; | |
171 | ||
3b2ce58b RK |
172 | /* Mount options */ |
173 | unsigned long ns_mount_opt; | |
174 | ||
574e6c31 RK |
175 | uid_t ns_resuid; |
176 | gid_t ns_resgid; | |
177 | unsigned long ns_interval; | |
178 | unsigned long ns_watermark; | |
179 | ||
65b4643d RK |
180 | /* Disk layout information (static) */ |
181 | unsigned int ns_blocksize_bits; | |
92c60cca | 182 | unsigned int ns_blocksize; |
65b4643d RK |
183 | unsigned long ns_nsegments; |
184 | unsigned long ns_blocks_per_segment; | |
185 | unsigned long ns_r_segments_percentage; | |
186 | unsigned long ns_nrsvsegs; | |
187 | unsigned long ns_first_data_block; | |
188 | int ns_inode_size; | |
189 | int ns_first_ino; | |
190 | u32 ns_crc_seed; | |
191 | }; | |
192 | ||
65b4643d RK |
193 | #define THE_NILFS_FNS(bit, name) \ |
194 | static inline void set_nilfs_##name(struct the_nilfs *nilfs) \ | |
195 | { \ | |
196 | set_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ | |
197 | } \ | |
198 | static inline void clear_nilfs_##name(struct the_nilfs *nilfs) \ | |
199 | { \ | |
200 | clear_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ | |
201 | } \ | |
202 | static inline int nilfs_##name(struct the_nilfs *nilfs) \ | |
203 | { \ | |
204 | return test_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ | |
205 | } | |
206 | ||
207 | THE_NILFS_FNS(INIT, init) | |
65b4643d | 208 | THE_NILFS_FNS(DISCONTINUED, discontinued) |
1cf58fa8 | 209 | THE_NILFS_FNS(GC_RUNNING, gc_running) |
e605f0a7 | 210 | THE_NILFS_FNS(SB_DIRTY, sb_dirty) |
65b4643d | 211 | |
3b2ce58b RK |
212 | /* |
213 | * Mount option operations | |
214 | */ | |
215 | #define nilfs_clear_opt(nilfs, opt) \ | |
216 | do { (nilfs)->ns_mount_opt &= ~NILFS_MOUNT_##opt; } while (0) | |
217 | #define nilfs_set_opt(nilfs, opt) \ | |
218 | do { (nilfs)->ns_mount_opt |= NILFS_MOUNT_##opt; } while (0) | |
219 | #define nilfs_test_opt(nilfs, opt) ((nilfs)->ns_mount_opt & NILFS_MOUNT_##opt) | |
220 | #define nilfs_write_opt(nilfs, mask, opt) \ | |
221 | do { (nilfs)->ns_mount_opt = \ | |
222 | (((nilfs)->ns_mount_opt & ~NILFS_MOUNT_##mask) | \ | |
223 | NILFS_MOUNT_##opt); \ | |
224 | } while (0) | |
225 | ||
ba65ae47 RK |
226 | /** |
227 | * struct nilfs_root - nilfs root object | |
228 | * @cno: checkpoint number | |
229 | * @rb_node: red-black tree node | |
230 | * @count: refcount of this structure | |
231 | * @nilfs: nilfs object | |
232 | * @ifile: inode file | |
ba65ae47 | 233 | * @inodes_count: number of inodes |
f5974c8f | 234 | * @blocks_count: number of blocks |
ba65ae47 RK |
235 | */ |
236 | struct nilfs_root { | |
237 | __u64 cno; | |
238 | struct rb_node rb_node; | |
239 | ||
240 | atomic_t count; | |
241 | struct the_nilfs *nilfs; | |
242 | struct inode *ifile; | |
243 | ||
244 | atomic_t inodes_count; | |
245 | atomic_t blocks_count; | |
246 | }; | |
247 | ||
248 | /* Special checkpoint number */ | |
249 | #define NILFS_CPTREE_CURRENT_CNO 0 | |
250 | ||
e339ad31 RK |
251 | /* Minimum interval of periodical update of superblocks (in seconds) */ |
252 | #define NILFS_SB_FREQ 10 | |
e339ad31 | 253 | |
79efdd94 JS |
254 | static inline int nilfs_sb_need_update(struct the_nilfs *nilfs) |
255 | { | |
256 | u64 t = get_seconds(); | |
b2ac86e1 | 257 | return t < nilfs->ns_sbwtime || t > nilfs->ns_sbwtime + NILFS_SB_FREQ; |
79efdd94 JS |
258 | } |
259 | ||
b2ac86e1 | 260 | static inline int nilfs_sb_will_flip(struct the_nilfs *nilfs) |
79efdd94 | 261 | { |
b2ac86e1 JS |
262 | int flip_bits = nilfs->ns_sbwcount & 0x0FL; |
263 | return (flip_bits != 0x08 && flip_bits != 0x0F); | |
79efdd94 JS |
264 | } |
265 | ||
65b4643d | 266 | void nilfs_set_last_segment(struct the_nilfs *, sector_t, u64, __u64); |
348fe8da RK |
267 | struct the_nilfs *alloc_nilfs(struct block_device *bdev); |
268 | void destroy_nilfs(struct the_nilfs *nilfs); | |
f7545144 RK |
269 | int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data); |
270 | int load_nilfs(struct the_nilfs *nilfs, struct super_block *sb); | |
4e33f9ea RK |
271 | unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs); |
272 | void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs); | |
e902ec99 | 273 | int nilfs_discard_segments(struct the_nilfs *, __u64 *, size_t); |
65b4643d | 274 | int nilfs_count_free_blocks(struct the_nilfs *, sector_t *); |
ba65ae47 RK |
275 | struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno); |
276 | struct nilfs_root *nilfs_find_or_create_root(struct the_nilfs *nilfs, | |
277 | __u64 cno); | |
278 | void nilfs_put_root(struct nilfs_root *root); | |
65b4643d | 279 | int nilfs_near_disk_full(struct the_nilfs *); |
e339ad31 RK |
280 | void nilfs_fall_back_super_block(struct the_nilfs *); |
281 | void nilfs_swap_super_block(struct the_nilfs *); | |
65b4643d RK |
282 | |
283 | ||
ba65ae47 RK |
284 | static inline void nilfs_get_root(struct nilfs_root *root) |
285 | { | |
286 | atomic_inc(&root->count); | |
287 | } | |
288 | ||
a057d2c0 RK |
289 | static inline int nilfs_valid_fs(struct the_nilfs *nilfs) |
290 | { | |
291 | unsigned valid_fs; | |
292 | ||
293 | down_read(&nilfs->ns_sem); | |
294 | valid_fs = (nilfs->ns_mount_state & NILFS_VALID_FS); | |
295 | up_read(&nilfs->ns_sem); | |
296 | return valid_fs; | |
297 | } | |
298 | ||
65b4643d RK |
299 | static inline void |
300 | nilfs_get_segment_range(struct the_nilfs *nilfs, __u64 segnum, | |
301 | sector_t *seg_start, sector_t *seg_end) | |
302 | { | |
303 | *seg_start = (sector_t)nilfs->ns_blocks_per_segment * segnum; | |
304 | *seg_end = *seg_start + nilfs->ns_blocks_per_segment - 1; | |
305 | if (segnum == 0) | |
306 | *seg_start = nilfs->ns_first_data_block; | |
307 | } | |
308 | ||
309 | static inline sector_t | |
310 | nilfs_get_segment_start_blocknr(struct the_nilfs *nilfs, __u64 segnum) | |
311 | { | |
312 | return (segnum == 0) ? nilfs->ns_first_data_block : | |
313 | (sector_t)nilfs->ns_blocks_per_segment * segnum; | |
314 | } | |
315 | ||
316 | static inline __u64 | |
317 | nilfs_get_segnum_of_block(struct the_nilfs *nilfs, sector_t blocknr) | |
318 | { | |
319 | sector_t segnum = blocknr; | |
320 | ||
321 | sector_div(segnum, nilfs->ns_blocks_per_segment); | |
322 | return segnum; | |
323 | } | |
324 | ||
325 | static inline void | |
326 | nilfs_terminate_segment(struct the_nilfs *nilfs, sector_t seg_start, | |
327 | sector_t seg_end) | |
328 | { | |
329 | /* terminate the current full segment (used in case of I/O-error) */ | |
330 | nilfs->ns_pseg_offset = seg_end - seg_start + 1; | |
331 | } | |
332 | ||
333 | static inline void nilfs_shift_to_next_segment(struct the_nilfs *nilfs) | |
334 | { | |
335 | /* move forward with a full segment */ | |
336 | nilfs->ns_segnum = nilfs->ns_nextnum; | |
337 | nilfs->ns_pseg_offset = 0; | |
338 | nilfs->ns_seg_seq++; | |
339 | } | |
340 | ||
341 | static inline __u64 nilfs_last_cno(struct the_nilfs *nilfs) | |
342 | { | |
343 | __u64 cno; | |
344 | ||
345 | spin_lock(&nilfs->ns_last_segment_lock); | |
346 | cno = nilfs->ns_last_cno; | |
347 | spin_unlock(&nilfs->ns_last_segment_lock); | |
348 | return cno; | |
349 | } | |
350 | ||
cece5520 RK |
351 | static inline int nilfs_segment_is_active(struct the_nilfs *nilfs, __u64 n) |
352 | { | |
353 | return n == nilfs->ns_segnum || n == nilfs->ns_nextnum; | |
354 | } | |
355 | ||
65b4643d | 356 | #endif /* _THE_NILFS_H */ |