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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 RK |
34 | #include "sb.h" |
35 | ||
36 | /* the_nilfs struct */ | |
37 | enum { | |
38 | THE_NILFS_INIT = 0, /* Information from super_block is set */ | |
65b4643d | 39 | THE_NILFS_DISCONTINUED, /* 'next' pointer chain has broken */ |
1cf58fa8 | 40 | THE_NILFS_GC_RUNNING, /* gc process is running */ |
e605f0a7 | 41 | THE_NILFS_SB_DIRTY, /* super block is dirty */ |
65b4643d RK |
42 | }; |
43 | ||
44 | /** | |
45 | * struct the_nilfs - struct to supervise multiple nilfs mount points | |
46 | * @ns_flags: flags | |
65b4643d | 47 | * @ns_bdev: block device |
65b4643d | 48 | * @ns_sem: semaphore for shared states |
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 |
65b4643d RK |
54 | * @ns_seg_seq: segment sequence counter |
55 | * @ns_segnum: index number of the latest full segment. | |
56 | * @ns_nextnum: index number of the full segment index to be used next | |
57 | * @ns_pseg_offset: offset of next partial segment in the current full segment | |
58 | * @ns_cno: next checkpoint number | |
59 | * @ns_ctime: write time of the last segment | |
60 | * @ns_nongc_ctime: write time of the last segment not for cleaner operation | |
61 | * @ns_ndirtyblks: Number of dirty data blocks | |
62 | * @ns_last_segment_lock: lock protecting fields for the latest segment | |
63 | * @ns_last_pseg: start block number of the latest segment | |
64 | * @ns_last_seq: sequence value of the latest segment | |
65 | * @ns_last_cno: checkpoint number of the latest segment | |
2c2e52fc | 66 | * @ns_prot_seq: least sequence number of segments which must not be reclaimed |
32502047 | 67 | * @ns_prev_seq: base sequence number used to decide if advance log cursor |
65b4643d RK |
68 | * @ns_segctor_sem: segment constructor semaphore |
69 | * @ns_dat: DAT file inode | |
70 | * @ns_cpfile: checkpoint file inode | |
71 | * @ns_sufile: segusage file inode | |
ba65ae47 RK |
72 | * @ns_cptree: rb-tree of all mounted checkpoints (nilfs_root) |
73 | * @ns_cptree_lock: lock protecting @ns_cptree | |
65b4643d | 74 | * @ns_gc_inodes: dummy inodes to keep live blocks |
3b2ce58b | 75 | * @ns_mount_opt: mount options |
574e6c31 RK |
76 | * @ns_resuid: uid for reserved blocks |
77 | * @ns_resgid: gid for reserved blocks | |
78 | * @ns_interval: checkpoint creation interval | |
79 | * @ns_watermark: watermark for the number of dirty buffers | |
65b4643d | 80 | * @ns_blocksize_bits: bit length of block size |
92c60cca | 81 | * @ns_blocksize: block size |
65b4643d RK |
82 | * @ns_nsegments: number of segments in filesystem |
83 | * @ns_blocks_per_segment: number of blocks per segment | |
84 | * @ns_r_segments_percentage: reserved segments percentage | |
85 | * @ns_nrsvsegs: number of reserved segments | |
86 | * @ns_first_data_block: block number of first data block | |
87 | * @ns_inode_size: size of on-disk inode | |
88 | * @ns_first_ino: first not-special inode number | |
89 | * @ns_crc_seed: seed value of CRC32 calculation | |
90 | */ | |
91 | struct the_nilfs { | |
92 | unsigned long ns_flags; | |
65b4643d RK |
93 | |
94 | struct block_device *ns_bdev; | |
65b4643d | 95 | struct rw_semaphore ns_sem; |
65b4643d RK |
96 | |
97 | /* | |
98 | * used for | |
99 | * - loading the latest checkpoint exclusively. | |
100 | * - allocating a new full segment. | |
101 | * - protecting s_dirt in the super_block struct | |
102 | * (see nilfs_write_super) and the following fields. | |
103 | */ | |
e339ad31 RK |
104 | struct buffer_head *ns_sbh[2]; |
105 | struct nilfs_super_block *ns_sbp[2]; | |
b2ac86e1 JS |
106 | time_t ns_sbwtime; |
107 | unsigned ns_sbwcount; | |
e339ad31 | 108 | unsigned ns_sbsize; |
65b4643d | 109 | unsigned ns_mount_state; |
65b4643d RK |
110 | |
111 | /* | |
112 | * Following fields are dedicated to a writable FS-instance. | |
113 | * Except for the period seeking checkpoint, code outside the segment | |
47420c79 RK |
114 | * constructor must lock a segment semaphore while accessing these |
115 | * fields. | |
65b4643d RK |
116 | * The writable FS-instance is sole during a lifetime of the_nilfs. |
117 | */ | |
118 | u64 ns_seg_seq; | |
119 | __u64 ns_segnum; | |
120 | __u64 ns_nextnum; | |
121 | unsigned long ns_pseg_offset; | |
122 | __u64 ns_cno; | |
123 | time_t ns_ctime; | |
124 | time_t ns_nongc_ctime; | |
125 | atomic_t ns_ndirtyblks; | |
126 | ||
127 | /* | |
128 | * The following fields hold information on the latest partial segment | |
129 | * written to disk with a super root. These fields are protected by | |
130 | * ns_last_segment_lock. | |
131 | */ | |
132 | spinlock_t ns_last_segment_lock; | |
133 | sector_t ns_last_pseg; | |
134 | u64 ns_last_seq; | |
135 | __u64 ns_last_cno; | |
2c2e52fc | 136 | u64 ns_prot_seq; |
32502047 | 137 | u64 ns_prev_seq; |
65b4643d RK |
138 | |
139 | struct rw_semaphore ns_segctor_sem; | |
140 | ||
141 | /* | |
142 | * Following fields are lock free except for the period before | |
143 | * the_nilfs is initialized. | |
144 | */ | |
145 | struct inode *ns_dat; | |
146 | struct inode *ns_cpfile; | |
147 | struct inode *ns_sufile; | |
65b4643d | 148 | |
ba65ae47 RK |
149 | /* Checkpoint tree */ |
150 | struct rb_root ns_cptree; | |
151 | spinlock_t ns_cptree_lock; | |
152 | ||
263d90ce | 153 | /* GC inode list */ |
65b4643d | 154 | struct list_head ns_gc_inodes; |
65b4643d | 155 | |
3b2ce58b RK |
156 | /* Mount options */ |
157 | unsigned long ns_mount_opt; | |
158 | ||
574e6c31 RK |
159 | uid_t ns_resuid; |
160 | gid_t ns_resgid; | |
161 | unsigned long ns_interval; | |
162 | unsigned long ns_watermark; | |
163 | ||
65b4643d RK |
164 | /* Disk layout information (static) */ |
165 | unsigned int ns_blocksize_bits; | |
92c60cca | 166 | unsigned int ns_blocksize; |
65b4643d RK |
167 | unsigned long ns_nsegments; |
168 | unsigned long ns_blocks_per_segment; | |
169 | unsigned long ns_r_segments_percentage; | |
170 | unsigned long ns_nrsvsegs; | |
171 | unsigned long ns_first_data_block; | |
172 | int ns_inode_size; | |
173 | int ns_first_ino; | |
174 | u32 ns_crc_seed; | |
175 | }; | |
176 | ||
65b4643d RK |
177 | #define THE_NILFS_FNS(bit, name) \ |
178 | static inline void set_nilfs_##name(struct the_nilfs *nilfs) \ | |
179 | { \ | |
180 | set_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ | |
181 | } \ | |
182 | static inline void clear_nilfs_##name(struct the_nilfs *nilfs) \ | |
183 | { \ | |
184 | clear_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ | |
185 | } \ | |
186 | static inline int nilfs_##name(struct the_nilfs *nilfs) \ | |
187 | { \ | |
188 | return test_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ | |
189 | } | |
190 | ||
191 | THE_NILFS_FNS(INIT, init) | |
65b4643d | 192 | THE_NILFS_FNS(DISCONTINUED, discontinued) |
1cf58fa8 | 193 | THE_NILFS_FNS(GC_RUNNING, gc_running) |
e605f0a7 | 194 | THE_NILFS_FNS(SB_DIRTY, sb_dirty) |
65b4643d | 195 | |
3b2ce58b RK |
196 | /* |
197 | * Mount option operations | |
198 | */ | |
199 | #define nilfs_clear_opt(nilfs, opt) \ | |
200 | do { (nilfs)->ns_mount_opt &= ~NILFS_MOUNT_##opt; } while (0) | |
201 | #define nilfs_set_opt(nilfs, opt) \ | |
202 | do { (nilfs)->ns_mount_opt |= NILFS_MOUNT_##opt; } while (0) | |
203 | #define nilfs_test_opt(nilfs, opt) ((nilfs)->ns_mount_opt & NILFS_MOUNT_##opt) | |
204 | #define nilfs_write_opt(nilfs, mask, opt) \ | |
205 | do { (nilfs)->ns_mount_opt = \ | |
206 | (((nilfs)->ns_mount_opt & ~NILFS_MOUNT_##mask) | \ | |
207 | NILFS_MOUNT_##opt); \ | |
208 | } while (0) | |
209 | ||
ba65ae47 RK |
210 | /** |
211 | * struct nilfs_root - nilfs root object | |
212 | * @cno: checkpoint number | |
213 | * @rb_node: red-black tree node | |
214 | * @count: refcount of this structure | |
215 | * @nilfs: nilfs object | |
216 | * @ifile: inode file | |
217 | * @root: root inode | |
218 | * @inodes_count: number of inodes | |
219 | * @blocks_count: number of blocks (Reserved) | |
220 | */ | |
221 | struct nilfs_root { | |
222 | __u64 cno; | |
223 | struct rb_node rb_node; | |
224 | ||
225 | atomic_t count; | |
226 | struct the_nilfs *nilfs; | |
227 | struct inode *ifile; | |
228 | ||
229 | atomic_t inodes_count; | |
230 | atomic_t blocks_count; | |
231 | }; | |
232 | ||
233 | /* Special checkpoint number */ | |
234 | #define NILFS_CPTREE_CURRENT_CNO 0 | |
235 | ||
e339ad31 RK |
236 | /* Minimum interval of periodical update of superblocks (in seconds) */ |
237 | #define NILFS_SB_FREQ 10 | |
e339ad31 | 238 | |
79efdd94 JS |
239 | static inline int nilfs_sb_need_update(struct the_nilfs *nilfs) |
240 | { | |
241 | u64 t = get_seconds(); | |
b2ac86e1 | 242 | return t < nilfs->ns_sbwtime || t > nilfs->ns_sbwtime + NILFS_SB_FREQ; |
79efdd94 JS |
243 | } |
244 | ||
b2ac86e1 | 245 | static inline int nilfs_sb_will_flip(struct the_nilfs *nilfs) |
79efdd94 | 246 | { |
b2ac86e1 JS |
247 | int flip_bits = nilfs->ns_sbwcount & 0x0FL; |
248 | return (flip_bits != 0x08 && flip_bits != 0x0F); | |
79efdd94 JS |
249 | } |
250 | ||
65b4643d | 251 | void nilfs_set_last_segment(struct the_nilfs *, sector_t, u64, __u64); |
348fe8da RK |
252 | struct the_nilfs *alloc_nilfs(struct block_device *bdev); |
253 | void destroy_nilfs(struct the_nilfs *nilfs); | |
65b4643d RK |
254 | int init_nilfs(struct the_nilfs *, struct nilfs_sb_info *, char *); |
255 | int load_nilfs(struct the_nilfs *, struct nilfs_sb_info *); | |
e902ec99 | 256 | int nilfs_discard_segments(struct the_nilfs *, __u64 *, size_t); |
65b4643d | 257 | int nilfs_count_free_blocks(struct the_nilfs *, sector_t *); |
ba65ae47 RK |
258 | struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno); |
259 | struct nilfs_root *nilfs_find_or_create_root(struct the_nilfs *nilfs, | |
260 | __u64 cno); | |
261 | void nilfs_put_root(struct nilfs_root *root); | |
6dd47406 | 262 | struct nilfs_sb_info *nilfs_find_sbinfo(struct the_nilfs *, int, __u64); |
65b4643d | 263 | int nilfs_near_disk_full(struct the_nilfs *); |
e339ad31 RK |
264 | void nilfs_fall_back_super_block(struct the_nilfs *); |
265 | void nilfs_swap_super_block(struct the_nilfs *); | |
65b4643d RK |
266 | |
267 | ||
ba65ae47 RK |
268 | static inline void nilfs_get_root(struct nilfs_root *root) |
269 | { | |
270 | atomic_inc(&root->count); | |
271 | } | |
272 | ||
a057d2c0 RK |
273 | static inline int nilfs_valid_fs(struct the_nilfs *nilfs) |
274 | { | |
275 | unsigned valid_fs; | |
276 | ||
277 | down_read(&nilfs->ns_sem); | |
278 | valid_fs = (nilfs->ns_mount_state & NILFS_VALID_FS); | |
279 | up_read(&nilfs->ns_sem); | |
280 | return valid_fs; | |
281 | } | |
282 | ||
65b4643d RK |
283 | static inline void |
284 | nilfs_get_segment_range(struct the_nilfs *nilfs, __u64 segnum, | |
285 | sector_t *seg_start, sector_t *seg_end) | |
286 | { | |
287 | *seg_start = (sector_t)nilfs->ns_blocks_per_segment * segnum; | |
288 | *seg_end = *seg_start + nilfs->ns_blocks_per_segment - 1; | |
289 | if (segnum == 0) | |
290 | *seg_start = nilfs->ns_first_data_block; | |
291 | } | |
292 | ||
293 | static inline sector_t | |
294 | nilfs_get_segment_start_blocknr(struct the_nilfs *nilfs, __u64 segnum) | |
295 | { | |
296 | return (segnum == 0) ? nilfs->ns_first_data_block : | |
297 | (sector_t)nilfs->ns_blocks_per_segment * segnum; | |
298 | } | |
299 | ||
300 | static inline __u64 | |
301 | nilfs_get_segnum_of_block(struct the_nilfs *nilfs, sector_t blocknr) | |
302 | { | |
303 | sector_t segnum = blocknr; | |
304 | ||
305 | sector_div(segnum, nilfs->ns_blocks_per_segment); | |
306 | return segnum; | |
307 | } | |
308 | ||
309 | static inline void | |
310 | nilfs_terminate_segment(struct the_nilfs *nilfs, sector_t seg_start, | |
311 | sector_t seg_end) | |
312 | { | |
313 | /* terminate the current full segment (used in case of I/O-error) */ | |
314 | nilfs->ns_pseg_offset = seg_end - seg_start + 1; | |
315 | } | |
316 | ||
317 | static inline void nilfs_shift_to_next_segment(struct the_nilfs *nilfs) | |
318 | { | |
319 | /* move forward with a full segment */ | |
320 | nilfs->ns_segnum = nilfs->ns_nextnum; | |
321 | nilfs->ns_pseg_offset = 0; | |
322 | nilfs->ns_seg_seq++; | |
323 | } | |
324 | ||
325 | static inline __u64 nilfs_last_cno(struct the_nilfs *nilfs) | |
326 | { | |
327 | __u64 cno; | |
328 | ||
329 | spin_lock(&nilfs->ns_last_segment_lock); | |
330 | cno = nilfs->ns_last_cno; | |
331 | spin_unlock(&nilfs->ns_last_segment_lock); | |
332 | return cno; | |
333 | } | |
334 | ||
cece5520 RK |
335 | static inline int nilfs_segment_is_active(struct the_nilfs *nilfs, __u64 n) |
336 | { | |
337 | return n == nilfs->ns_segnum || n == nilfs->ns_nextnum; | |
338 | } | |
339 | ||
65b4643d | 340 | #endif /* _THE_NILFS_H */ |