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Commit | Line | Data |
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29619809 KS |
1 | /* |
2 | * cpfile.c - NILFS checkpoint file. | |
3 | * | |
4 | * Copyright (C) 2006-2008 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 Koji Sato <koji@osrg.net>. | |
21 | */ | |
22 | ||
23 | #include <linux/kernel.h> | |
24 | #include <linux/fs.h> | |
25 | #include <linux/string.h> | |
26 | #include <linux/buffer_head.h> | |
27 | #include <linux/errno.h> | |
28 | #include <linux/nilfs2_fs.h> | |
29 | #include "mdt.h" | |
30 | #include "cpfile.h" | |
31 | ||
32 | ||
33 | static inline unsigned long | |
34 | nilfs_cpfile_checkpoints_per_block(const struct inode *cpfile) | |
35 | { | |
36 | return NILFS_MDT(cpfile)->mi_entries_per_block; | |
37 | } | |
38 | ||
39 | /* block number from the beginning of the file */ | |
40 | static unsigned long | |
41 | nilfs_cpfile_get_blkoff(const struct inode *cpfile, __u64 cno) | |
42 | { | |
43 | __u64 tcno; | |
44 | ||
45 | BUG_ON(cno == 0); /* checkpoint number 0 is invalid */ | |
46 | tcno = cno + NILFS_MDT(cpfile)->mi_first_entry_offset - 1; | |
47 | do_div(tcno, nilfs_cpfile_checkpoints_per_block(cpfile)); | |
48 | return (unsigned long)tcno; | |
49 | } | |
50 | ||
51 | /* offset in block */ | |
52 | static unsigned long | |
53 | nilfs_cpfile_get_offset(const struct inode *cpfile, __u64 cno) | |
54 | { | |
55 | __u64 tcno = cno + NILFS_MDT(cpfile)->mi_first_entry_offset - 1; | |
56 | return do_div(tcno, nilfs_cpfile_checkpoints_per_block(cpfile)); | |
57 | } | |
58 | ||
59 | static unsigned long | |
60 | nilfs_cpfile_checkpoints_in_block(const struct inode *cpfile, | |
61 | __u64 curr, | |
62 | __u64 max) | |
63 | { | |
64 | return min_t(__u64, | |
65 | nilfs_cpfile_checkpoints_per_block(cpfile) - | |
66 | nilfs_cpfile_get_offset(cpfile, curr), | |
67 | max - curr); | |
68 | } | |
69 | ||
70 | static inline int nilfs_cpfile_is_in_first(const struct inode *cpfile, | |
71 | __u64 cno) | |
72 | { | |
73 | return nilfs_cpfile_get_blkoff(cpfile, cno) == 0; | |
74 | } | |
75 | ||
76 | static unsigned int | |
77 | nilfs_cpfile_block_add_valid_checkpoints(const struct inode *cpfile, | |
78 | struct buffer_head *bh, | |
79 | void *kaddr, | |
80 | unsigned int n) | |
81 | { | |
82 | struct nilfs_checkpoint *cp = kaddr + bh_offset(bh); | |
83 | unsigned int count; | |
84 | ||
85 | count = le32_to_cpu(cp->cp_checkpoints_count) + n; | |
86 | cp->cp_checkpoints_count = cpu_to_le32(count); | |
87 | return count; | |
88 | } | |
89 | ||
90 | static unsigned int | |
91 | nilfs_cpfile_block_sub_valid_checkpoints(const struct inode *cpfile, | |
92 | struct buffer_head *bh, | |
93 | void *kaddr, | |
94 | unsigned int n) | |
95 | { | |
96 | struct nilfs_checkpoint *cp = kaddr + bh_offset(bh); | |
97 | unsigned int count; | |
98 | ||
99 | BUG_ON(le32_to_cpu(cp->cp_checkpoints_count) < n); | |
100 | count = le32_to_cpu(cp->cp_checkpoints_count) - n; | |
101 | cp->cp_checkpoints_count = cpu_to_le32(count); | |
102 | return count; | |
103 | } | |
104 | ||
105 | static inline struct nilfs_cpfile_header * | |
106 | nilfs_cpfile_block_get_header(const struct inode *cpfile, | |
107 | struct buffer_head *bh, | |
108 | void *kaddr) | |
109 | { | |
110 | return kaddr + bh_offset(bh); | |
111 | } | |
112 | ||
113 | static struct nilfs_checkpoint * | |
114 | nilfs_cpfile_block_get_checkpoint(const struct inode *cpfile, __u64 cno, | |
115 | struct buffer_head *bh, | |
116 | void *kaddr) | |
117 | { | |
118 | return kaddr + bh_offset(bh) + nilfs_cpfile_get_offset(cpfile, cno) * | |
119 | NILFS_MDT(cpfile)->mi_entry_size; | |
120 | } | |
121 | ||
122 | static void nilfs_cpfile_block_init(struct inode *cpfile, | |
123 | struct buffer_head *bh, | |
124 | void *kaddr) | |
125 | { | |
126 | struct nilfs_checkpoint *cp = kaddr + bh_offset(bh); | |
127 | size_t cpsz = NILFS_MDT(cpfile)->mi_entry_size; | |
128 | int n = nilfs_cpfile_checkpoints_per_block(cpfile); | |
129 | ||
130 | while (n-- > 0) { | |
131 | nilfs_checkpoint_set_invalid(cp); | |
132 | cp = (void *)cp + cpsz; | |
133 | } | |
134 | } | |
135 | ||
136 | static inline int nilfs_cpfile_get_header_block(struct inode *cpfile, | |
137 | struct buffer_head **bhp) | |
138 | { | |
139 | return nilfs_mdt_get_block(cpfile, 0, 0, NULL, bhp); | |
140 | } | |
141 | ||
142 | static inline int nilfs_cpfile_get_checkpoint_block(struct inode *cpfile, | |
143 | __u64 cno, | |
144 | int create, | |
145 | struct buffer_head **bhp) | |
146 | { | |
147 | return nilfs_mdt_get_block(cpfile, | |
148 | nilfs_cpfile_get_blkoff(cpfile, cno), | |
149 | create, nilfs_cpfile_block_init, bhp); | |
150 | } | |
151 | ||
152 | static inline int nilfs_cpfile_delete_checkpoint_block(struct inode *cpfile, | |
153 | __u64 cno) | |
154 | { | |
155 | return nilfs_mdt_delete_block(cpfile, | |
156 | nilfs_cpfile_get_blkoff(cpfile, cno)); | |
157 | } | |
158 | ||
159 | /** | |
160 | * nilfs_cpfile_get_checkpoint - get a checkpoint | |
161 | * @cpfile: inode of checkpoint file | |
162 | * @cno: checkpoint number | |
163 | * @create: create flag | |
164 | * @cpp: pointer to a checkpoint | |
165 | * @bhp: pointer to a buffer head | |
166 | * | |
167 | * Description: nilfs_cpfile_get_checkpoint() acquires the checkpoint | |
168 | * specified by @cno. A new checkpoint will be created if @cno is the current | |
169 | * checkpoint number and @create is nonzero. | |
170 | * | |
171 | * Return Value: On success, 0 is returned, and the checkpoint and the | |
172 | * buffer head of the buffer on which the checkpoint is located are stored in | |
173 | * the place pointed by @cpp and @bhp, respectively. On error, one of the | |
174 | * following negative error codes is returned. | |
175 | * | |
176 | * %-EIO - I/O error. | |
177 | * | |
178 | * %-ENOMEM - Insufficient amount of memory available. | |
179 | * | |
180 | * %-ENOENT - No such checkpoint. | |
181 | */ | |
182 | int nilfs_cpfile_get_checkpoint(struct inode *cpfile, | |
183 | __u64 cno, | |
184 | int create, | |
185 | struct nilfs_checkpoint **cpp, | |
186 | struct buffer_head **bhp) | |
187 | { | |
188 | struct buffer_head *header_bh, *cp_bh; | |
189 | struct nilfs_cpfile_header *header; | |
190 | struct nilfs_checkpoint *cp; | |
191 | void *kaddr; | |
192 | int ret; | |
193 | ||
194 | BUG_ON(cno < 1 || cno > nilfs_mdt_cno(cpfile) || | |
195 | (cno < nilfs_mdt_cno(cpfile) && create)); | |
196 | ||
197 | down_write(&NILFS_MDT(cpfile)->mi_sem); | |
198 | ||
199 | ret = nilfs_cpfile_get_header_block(cpfile, &header_bh); | |
200 | if (ret < 0) | |
201 | goto out_sem; | |
202 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, create, &cp_bh); | |
203 | if (ret < 0) | |
204 | goto out_header; | |
205 | kaddr = kmap(cp_bh->b_page); | |
206 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr); | |
207 | if (nilfs_checkpoint_invalid(cp)) { | |
208 | if (!create) { | |
209 | kunmap(cp_bh->b_page); | |
210 | brelse(cp_bh); | |
211 | ret = -ENOENT; | |
212 | goto out_header; | |
213 | } | |
214 | /* a newly-created checkpoint */ | |
215 | nilfs_checkpoint_clear_invalid(cp); | |
216 | if (!nilfs_cpfile_is_in_first(cpfile, cno)) | |
217 | nilfs_cpfile_block_add_valid_checkpoints(cpfile, cp_bh, | |
218 | kaddr, 1); | |
219 | nilfs_mdt_mark_buffer_dirty(cp_bh); | |
220 | ||
221 | kaddr = kmap_atomic(header_bh->b_page, KM_USER0); | |
222 | header = nilfs_cpfile_block_get_header(cpfile, header_bh, | |
223 | kaddr); | |
224 | le64_add_cpu(&header->ch_ncheckpoints, 1); | |
225 | kunmap_atomic(kaddr, KM_USER0); | |
226 | nilfs_mdt_mark_buffer_dirty(header_bh); | |
227 | nilfs_mdt_mark_dirty(cpfile); | |
228 | } | |
229 | ||
230 | if (cpp != NULL) | |
231 | *cpp = cp; | |
232 | *bhp = cp_bh; | |
233 | ||
234 | out_header: | |
235 | brelse(header_bh); | |
236 | ||
237 | out_sem: | |
238 | up_write(&NILFS_MDT(cpfile)->mi_sem); | |
239 | return ret; | |
240 | } | |
241 | ||
242 | /** | |
243 | * nilfs_cpfile_put_checkpoint - put a checkpoint | |
244 | * @cpfile: inode of checkpoint file | |
245 | * @cno: checkpoint number | |
246 | * @bh: buffer head | |
247 | * | |
248 | * Description: nilfs_cpfile_put_checkpoint() releases the checkpoint | |
249 | * specified by @cno. @bh must be the buffer head which has been returned by | |
250 | * a previous call to nilfs_cpfile_get_checkpoint() with @cno. | |
251 | */ | |
252 | void nilfs_cpfile_put_checkpoint(struct inode *cpfile, __u64 cno, | |
253 | struct buffer_head *bh) | |
254 | { | |
255 | kunmap(bh->b_page); | |
256 | brelse(bh); | |
257 | } | |
258 | ||
259 | /** | |
260 | * nilfs_cpfile_delete_checkpoints - delete checkpoints | |
261 | * @cpfile: inode of checkpoint file | |
262 | * @start: start checkpoint number | |
263 | * @end: end checkpoint numer | |
264 | * | |
265 | * Description: nilfs_cpfile_delete_checkpoints() deletes the checkpoints in | |
266 | * the period from @start to @end, excluding @end itself. The checkpoints | |
267 | * which have been already deleted are ignored. | |
268 | * | |
269 | * Return Value: On success, 0 is returned. On error, one of the following | |
270 | * negative error codes is returned. | |
271 | * | |
272 | * %-EIO - I/O error. | |
273 | * | |
274 | * %-ENOMEM - Insufficient amount of memory available. | |
275 | * | |
276 | * %-EINVAL - invalid checkpoints. | |
277 | */ | |
278 | int nilfs_cpfile_delete_checkpoints(struct inode *cpfile, | |
279 | __u64 start, | |
280 | __u64 end) | |
281 | { | |
282 | struct buffer_head *header_bh, *cp_bh; | |
283 | struct nilfs_cpfile_header *header; | |
284 | struct nilfs_checkpoint *cp; | |
285 | size_t cpsz = NILFS_MDT(cpfile)->mi_entry_size; | |
286 | __u64 cno; | |
287 | void *kaddr; | |
288 | unsigned long tnicps; | |
289 | int ret, ncps, nicps, count, i; | |
290 | ||
291 | if ((start == 0) || (start > end)) { | |
292 | printk(KERN_CRIT "%s: start = %llu, end = %llu\n", | |
293 | __func__, | |
294 | (unsigned long long)start, | |
295 | (unsigned long long)end); | |
296 | BUG(); | |
297 | } | |
298 | ||
299 | /* cannot delete the latest checkpoint */ | |
300 | if (start == nilfs_mdt_cno(cpfile) - 1) | |
301 | return -EPERM; | |
302 | ||
303 | down_write(&NILFS_MDT(cpfile)->mi_sem); | |
304 | ||
305 | ret = nilfs_cpfile_get_header_block(cpfile, &header_bh); | |
306 | if (ret < 0) | |
307 | goto out_sem; | |
308 | tnicps = 0; | |
309 | ||
310 | for (cno = start; cno < end; cno += ncps) { | |
311 | ncps = nilfs_cpfile_checkpoints_in_block(cpfile, cno, end); | |
312 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh); | |
313 | if (ret < 0) { | |
314 | if (ret != -ENOENT) | |
315 | goto out_sem; | |
316 | /* skip hole */ | |
317 | ret = 0; | |
318 | continue; | |
319 | } | |
320 | ||
321 | kaddr = kmap_atomic(cp_bh->b_page, KM_USER0); | |
322 | cp = nilfs_cpfile_block_get_checkpoint( | |
323 | cpfile, cno, cp_bh, kaddr); | |
324 | nicps = 0; | |
325 | for (i = 0; i < ncps; i++, cp = (void *)cp + cpsz) { | |
326 | BUG_ON(nilfs_checkpoint_snapshot(cp)); | |
327 | if (!nilfs_checkpoint_invalid(cp)) { | |
328 | nilfs_checkpoint_set_invalid(cp); | |
329 | nicps++; | |
330 | } | |
331 | } | |
332 | if (nicps > 0) { | |
333 | tnicps += nicps; | |
334 | nilfs_mdt_mark_buffer_dirty(cp_bh); | |
335 | nilfs_mdt_mark_dirty(cpfile); | |
336 | if (!nilfs_cpfile_is_in_first(cpfile, cno) && | |
337 | (count = nilfs_cpfile_block_sub_valid_checkpoints( | |
338 | cpfile, cp_bh, kaddr, nicps)) == 0) { | |
339 | /* make hole */ | |
340 | kunmap_atomic(kaddr, KM_USER0); | |
341 | brelse(cp_bh); | |
342 | ret = nilfs_cpfile_delete_checkpoint_block( | |
343 | cpfile, cno); | |
344 | if (ret == 0) | |
345 | continue; | |
346 | printk(KERN_ERR "%s: cannot delete block\n", | |
347 | __func__); | |
348 | goto out_sem; | |
349 | } | |
350 | } | |
351 | ||
352 | kunmap_atomic(kaddr, KM_USER0); | |
353 | brelse(cp_bh); | |
354 | } | |
355 | ||
356 | if (tnicps > 0) { | |
357 | kaddr = kmap_atomic(header_bh->b_page, KM_USER0); | |
358 | header = nilfs_cpfile_block_get_header(cpfile, header_bh, | |
359 | kaddr); | |
6c98cd4e | 360 | le64_add_cpu(&header->ch_ncheckpoints, -(u64)tnicps); |
29619809 KS |
361 | nilfs_mdt_mark_buffer_dirty(header_bh); |
362 | nilfs_mdt_mark_dirty(cpfile); | |
363 | kunmap_atomic(kaddr, KM_USER0); | |
364 | } | |
365 | brelse(header_bh); | |
366 | ||
367 | out_sem: | |
368 | up_write(&NILFS_MDT(cpfile)->mi_sem); | |
369 | return ret; | |
370 | } | |
371 | ||
372 | static void nilfs_cpfile_checkpoint_to_cpinfo(struct inode *cpfile, | |
373 | struct nilfs_checkpoint *cp, | |
374 | struct nilfs_cpinfo *ci) | |
375 | { | |
376 | ci->ci_flags = le32_to_cpu(cp->cp_flags); | |
377 | ci->ci_cno = le64_to_cpu(cp->cp_cno); | |
378 | ci->ci_create = le64_to_cpu(cp->cp_create); | |
379 | ci->ci_nblk_inc = le64_to_cpu(cp->cp_nblk_inc); | |
380 | ci->ci_inodes_count = le64_to_cpu(cp->cp_inodes_count); | |
381 | ci->ci_blocks_count = le64_to_cpu(cp->cp_blocks_count); | |
382 | ci->ci_next = le64_to_cpu(cp->cp_snapshot_list.ssl_next); | |
383 | } | |
384 | ||
385 | static ssize_t nilfs_cpfile_do_get_cpinfo(struct inode *cpfile, __u64 cno, | |
386 | struct nilfs_cpinfo *ci, size_t nci) | |
387 | { | |
388 | struct nilfs_checkpoint *cp; | |
389 | struct buffer_head *bh; | |
390 | size_t cpsz = NILFS_MDT(cpfile)->mi_entry_size; | |
391 | __u64 cur_cno = nilfs_mdt_cno(cpfile); | |
392 | void *kaddr; | |
393 | int n, ret; | |
394 | int ncps, i; | |
395 | ||
396 | down_read(&NILFS_MDT(cpfile)->mi_sem); | |
397 | ||
398 | for (n = 0; cno < cur_cno && n < nci; cno += ncps) { | |
399 | ncps = nilfs_cpfile_checkpoints_in_block(cpfile, cno, cur_cno); | |
400 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &bh); | |
401 | if (ret < 0) { | |
402 | if (ret != -ENOENT) | |
403 | goto out; | |
404 | continue; /* skip hole */ | |
405 | } | |
406 | ||
407 | kaddr = kmap_atomic(bh->b_page, KM_USER0); | |
408 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr); | |
409 | for (i = 0; i < ncps && n < nci; i++, cp = (void *)cp + cpsz) { | |
410 | if (!nilfs_checkpoint_invalid(cp)) | |
411 | nilfs_cpfile_checkpoint_to_cpinfo( | |
412 | cpfile, cp, &ci[n++]); | |
413 | } | |
414 | kunmap_atomic(kaddr, KM_USER0); | |
415 | brelse(bh); | |
416 | } | |
417 | ||
418 | ret = n; | |
419 | ||
420 | out: | |
421 | up_read(&NILFS_MDT(cpfile)->mi_sem); | |
422 | return ret; | |
423 | } | |
424 | ||
b028fcfc | 425 | static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 *cnop, |
29619809 KS |
426 | struct nilfs_cpinfo *ci, size_t nci) |
427 | { | |
428 | struct buffer_head *bh; | |
429 | struct nilfs_cpfile_header *header; | |
430 | struct nilfs_checkpoint *cp; | |
b028fcfc | 431 | __u64 curr = *cnop, next; |
29619809 KS |
432 | unsigned long curr_blkoff, next_blkoff; |
433 | void *kaddr; | |
7fa10d20 | 434 | int n = 0, ret; |
29619809 KS |
435 | |
436 | down_read(&NILFS_MDT(cpfile)->mi_sem); | |
437 | ||
b028fcfc | 438 | if (curr == 0) { |
29619809 KS |
439 | ret = nilfs_cpfile_get_header_block(cpfile, &bh); |
440 | if (ret < 0) | |
441 | goto out; | |
442 | kaddr = kmap_atomic(bh->b_page, KM_USER0); | |
443 | header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr); | |
444 | curr = le64_to_cpu(header->ch_snapshot_list.ssl_next); | |
445 | kunmap_atomic(kaddr, KM_USER0); | |
446 | brelse(bh); | |
447 | if (curr == 0) { | |
448 | ret = 0; | |
449 | goto out; | |
450 | } | |
b028fcfc RK |
451 | } else if (unlikely(curr == ~(__u64)0)) { |
452 | ret = 0; | |
453 | goto out; | |
454 | } | |
455 | ||
29619809 KS |
456 | curr_blkoff = nilfs_cpfile_get_blkoff(cpfile, curr); |
457 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, curr, 0, &bh); | |
7fa10d20 RK |
458 | if (unlikely(ret < 0)) { |
459 | if (ret == -ENOENT) | |
460 | ret = 0; /* No snapshots (started from a hole block) */ | |
29619809 | 461 | goto out; |
7fa10d20 | 462 | } |
29619809 | 463 | kaddr = kmap_atomic(bh->b_page, KM_USER0); |
7fa10d20 RK |
464 | while (n < nci) { |
465 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, curr, bh, kaddr); | |
466 | curr = ~(__u64)0; /* Terminator */ | |
467 | if (unlikely(nilfs_checkpoint_invalid(cp) || | |
468 | !nilfs_checkpoint_snapshot(cp))) | |
29619809 | 469 | break; |
7fa10d20 RK |
470 | nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp, &ci[n++]); |
471 | next = le64_to_cpu(cp->cp_snapshot_list.ssl_next); | |
472 | if (next == 0) | |
473 | break; /* reach end of the snapshot list */ | |
474 | ||
29619809 KS |
475 | next_blkoff = nilfs_cpfile_get_blkoff(cpfile, next); |
476 | if (curr_blkoff != next_blkoff) { | |
477 | kunmap_atomic(kaddr, KM_USER0); | |
478 | brelse(bh); | |
479 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, next, | |
480 | 0, &bh); | |
7fa10d20 RK |
481 | if (unlikely(ret < 0)) { |
482 | WARN_ON(ret == -ENOENT); | |
29619809 | 483 | goto out; |
7fa10d20 | 484 | } |
29619809 KS |
485 | kaddr = kmap_atomic(bh->b_page, KM_USER0); |
486 | } | |
487 | curr = next; | |
488 | curr_blkoff = next_blkoff; | |
489 | } | |
490 | kunmap_atomic(kaddr, KM_USER0); | |
491 | brelse(bh); | |
b028fcfc | 492 | *cnop = curr; |
29619809 KS |
493 | ret = n; |
494 | ||
495 | out: | |
496 | up_read(&NILFS_MDT(cpfile)->mi_sem); | |
497 | return ret; | |
498 | } | |
499 | ||
500 | /** | |
501 | * nilfs_cpfile_get_cpinfo - | |
502 | * @cpfile: | |
503 | * @cno: | |
504 | * @ci: | |
505 | * @nci: | |
506 | */ | |
b028fcfc RK |
507 | |
508 | ssize_t nilfs_cpfile_get_cpinfo(struct inode *cpfile, __u64 *cnop, int mode, | |
29619809 KS |
509 | struct nilfs_cpinfo *ci, size_t nci) |
510 | { | |
511 | switch (mode) { | |
512 | case NILFS_CHECKPOINT: | |
b028fcfc | 513 | return nilfs_cpfile_do_get_cpinfo(cpfile, *cnop, ci, nci); |
29619809 | 514 | case NILFS_SNAPSHOT: |
b028fcfc | 515 | return nilfs_cpfile_do_get_ssinfo(cpfile, cnop, ci, nci); |
29619809 KS |
516 | default: |
517 | return -EINVAL; | |
518 | } | |
519 | } | |
520 | ||
521 | /** | |
522 | * nilfs_cpfile_delete_checkpoint - | |
523 | * @cpfile: | |
524 | * @cno: | |
525 | */ | |
526 | int nilfs_cpfile_delete_checkpoint(struct inode *cpfile, __u64 cno) | |
527 | { | |
528 | struct nilfs_cpinfo ci; | |
529 | ssize_t nci; | |
530 | int ret; | |
531 | ||
532 | /* checkpoint number 0 is invalid */ | |
533 | if (cno == 0) | |
534 | return -ENOENT; | |
535 | nci = nilfs_cpfile_do_get_cpinfo(cpfile, cno, &ci, 1); | |
536 | if (nci < 0) | |
537 | return nci; | |
538 | else if (nci == 0 || ci.ci_cno != cno) | |
539 | return -ENOENT; | |
540 | ||
541 | /* cannot delete the latest checkpoint nor snapshots */ | |
542 | ret = nilfs_cpinfo_snapshot(&ci); | |
543 | if (ret < 0) | |
544 | return ret; | |
545 | else if (ret > 0 || cno == nilfs_mdt_cno(cpfile) - 1) | |
546 | return -EPERM; | |
547 | ||
548 | return nilfs_cpfile_delete_checkpoints(cpfile, cno, cno + 1); | |
549 | } | |
550 | ||
551 | static struct nilfs_snapshot_list * | |
552 | nilfs_cpfile_block_get_snapshot_list(const struct inode *cpfile, | |
553 | __u64 cno, | |
554 | struct buffer_head *bh, | |
555 | void *kaddr) | |
556 | { | |
557 | struct nilfs_cpfile_header *header; | |
558 | struct nilfs_checkpoint *cp; | |
559 | struct nilfs_snapshot_list *list; | |
560 | ||
561 | if (cno != 0) { | |
562 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr); | |
563 | list = &cp->cp_snapshot_list; | |
564 | } else { | |
565 | header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr); | |
566 | list = &header->ch_snapshot_list; | |
567 | } | |
568 | return list; | |
569 | } | |
570 | ||
571 | static int nilfs_cpfile_set_snapshot(struct inode *cpfile, __u64 cno) | |
572 | { | |
573 | struct buffer_head *header_bh, *curr_bh, *prev_bh, *cp_bh; | |
574 | struct nilfs_cpfile_header *header; | |
575 | struct nilfs_checkpoint *cp; | |
576 | struct nilfs_snapshot_list *list; | |
577 | __u64 curr, prev; | |
578 | unsigned long curr_blkoff, prev_blkoff; | |
579 | void *kaddr; | |
580 | int ret; | |
581 | ||
582 | down_write(&NILFS_MDT(cpfile)->mi_sem); | |
583 | ||
584 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh); | |
585 | if (ret < 0) | |
586 | goto out_sem; | |
587 | kaddr = kmap_atomic(cp_bh->b_page, KM_USER0); | |
588 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr); | |
589 | if (nilfs_checkpoint_invalid(cp)) { | |
590 | ret = -ENOENT; | |
591 | kunmap_atomic(kaddr, KM_USER0); | |
592 | goto out_cp; | |
593 | } | |
594 | if (nilfs_checkpoint_snapshot(cp)) { | |
595 | ret = 0; | |
596 | kunmap_atomic(kaddr, KM_USER0); | |
597 | goto out_cp; | |
598 | } | |
599 | kunmap_atomic(kaddr, KM_USER0); | |
600 | ||
601 | ret = nilfs_cpfile_get_header_block(cpfile, &header_bh); | |
602 | if (ret < 0) | |
603 | goto out_cp; | |
604 | kaddr = kmap_atomic(header_bh->b_page, KM_USER0); | |
605 | header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr); | |
606 | list = &header->ch_snapshot_list; | |
607 | curr_bh = header_bh; | |
608 | get_bh(curr_bh); | |
609 | curr = 0; | |
610 | curr_blkoff = 0; | |
611 | prev = le64_to_cpu(list->ssl_prev); | |
612 | while (prev > cno) { | |
613 | prev_blkoff = nilfs_cpfile_get_blkoff(cpfile, prev); | |
614 | curr = prev; | |
615 | if (curr_blkoff != prev_blkoff) { | |
616 | kunmap_atomic(kaddr, KM_USER0); | |
617 | brelse(curr_bh); | |
618 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, curr, | |
619 | 0, &curr_bh); | |
620 | if (ret < 0) | |
621 | goto out_header; | |
622 | kaddr = kmap_atomic(curr_bh->b_page, KM_USER0); | |
623 | } | |
624 | curr_blkoff = prev_blkoff; | |
625 | cp = nilfs_cpfile_block_get_checkpoint( | |
626 | cpfile, curr, curr_bh, kaddr); | |
627 | list = &cp->cp_snapshot_list; | |
628 | prev = le64_to_cpu(list->ssl_prev); | |
629 | } | |
630 | kunmap_atomic(kaddr, KM_USER0); | |
631 | ||
632 | if (prev != 0) { | |
633 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, prev, 0, | |
634 | &prev_bh); | |
635 | if (ret < 0) | |
636 | goto out_curr; | |
637 | } else { | |
638 | prev_bh = header_bh; | |
639 | get_bh(prev_bh); | |
640 | } | |
641 | ||
642 | kaddr = kmap_atomic(curr_bh->b_page, KM_USER0); | |
643 | list = nilfs_cpfile_block_get_snapshot_list( | |
644 | cpfile, curr, curr_bh, kaddr); | |
645 | list->ssl_prev = cpu_to_le64(cno); | |
646 | kunmap_atomic(kaddr, KM_USER0); | |
647 | ||
648 | kaddr = kmap_atomic(cp_bh->b_page, KM_USER0); | |
649 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr); | |
650 | cp->cp_snapshot_list.ssl_next = cpu_to_le64(curr); | |
651 | cp->cp_snapshot_list.ssl_prev = cpu_to_le64(prev); | |
652 | nilfs_checkpoint_set_snapshot(cp); | |
653 | kunmap_atomic(kaddr, KM_USER0); | |
654 | ||
655 | kaddr = kmap_atomic(prev_bh->b_page, KM_USER0); | |
656 | list = nilfs_cpfile_block_get_snapshot_list( | |
657 | cpfile, prev, prev_bh, kaddr); | |
658 | list->ssl_next = cpu_to_le64(cno); | |
659 | kunmap_atomic(kaddr, KM_USER0); | |
660 | ||
661 | kaddr = kmap_atomic(header_bh->b_page, KM_USER0); | |
662 | header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr); | |
663 | le64_add_cpu(&header->ch_nsnapshots, 1); | |
664 | kunmap_atomic(kaddr, KM_USER0); | |
665 | ||
666 | nilfs_mdt_mark_buffer_dirty(prev_bh); | |
667 | nilfs_mdt_mark_buffer_dirty(curr_bh); | |
668 | nilfs_mdt_mark_buffer_dirty(cp_bh); | |
669 | nilfs_mdt_mark_buffer_dirty(header_bh); | |
670 | nilfs_mdt_mark_dirty(cpfile); | |
671 | ||
672 | brelse(prev_bh); | |
673 | ||
674 | out_curr: | |
675 | brelse(curr_bh); | |
676 | ||
677 | out_header: | |
678 | brelse(header_bh); | |
679 | ||
680 | out_cp: | |
681 | brelse(cp_bh); | |
682 | ||
683 | out_sem: | |
684 | up_write(&NILFS_MDT(cpfile)->mi_sem); | |
685 | return ret; | |
686 | } | |
687 | ||
688 | static int nilfs_cpfile_clear_snapshot(struct inode *cpfile, __u64 cno) | |
689 | { | |
690 | struct buffer_head *header_bh, *next_bh, *prev_bh, *cp_bh; | |
691 | struct nilfs_cpfile_header *header; | |
692 | struct nilfs_checkpoint *cp; | |
693 | struct nilfs_snapshot_list *list; | |
694 | __u64 next, prev; | |
695 | void *kaddr; | |
696 | int ret; | |
697 | ||
698 | down_write(&NILFS_MDT(cpfile)->mi_sem); | |
699 | ||
700 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh); | |
701 | if (ret < 0) | |
702 | goto out_sem; | |
703 | kaddr = kmap_atomic(cp_bh->b_page, KM_USER0); | |
704 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr); | |
705 | if (nilfs_checkpoint_invalid(cp)) { | |
706 | ret = -ENOENT; | |
707 | kunmap_atomic(kaddr, KM_USER0); | |
708 | goto out_cp; | |
709 | } | |
710 | if (!nilfs_checkpoint_snapshot(cp)) { | |
711 | ret = 0; | |
712 | kunmap_atomic(kaddr, KM_USER0); | |
713 | goto out_cp; | |
714 | } | |
715 | ||
716 | list = &cp->cp_snapshot_list; | |
717 | next = le64_to_cpu(list->ssl_next); | |
718 | prev = le64_to_cpu(list->ssl_prev); | |
719 | kunmap_atomic(kaddr, KM_USER0); | |
720 | ||
721 | ret = nilfs_cpfile_get_header_block(cpfile, &header_bh); | |
722 | if (ret < 0) | |
723 | goto out_cp; | |
724 | if (next != 0) { | |
725 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, next, 0, | |
726 | &next_bh); | |
727 | if (ret < 0) | |
728 | goto out_header; | |
729 | } else { | |
730 | next_bh = header_bh; | |
731 | get_bh(next_bh); | |
732 | } | |
733 | if (prev != 0) { | |
734 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, prev, 0, | |
735 | &prev_bh); | |
736 | if (ret < 0) | |
737 | goto out_next; | |
738 | } else { | |
739 | prev_bh = header_bh; | |
740 | get_bh(prev_bh); | |
741 | } | |
742 | ||
743 | kaddr = kmap_atomic(next_bh->b_page, KM_USER0); | |
744 | list = nilfs_cpfile_block_get_snapshot_list( | |
745 | cpfile, next, next_bh, kaddr); | |
746 | list->ssl_prev = cpu_to_le64(prev); | |
747 | kunmap_atomic(kaddr, KM_USER0); | |
748 | ||
749 | kaddr = kmap_atomic(prev_bh->b_page, KM_USER0); | |
750 | list = nilfs_cpfile_block_get_snapshot_list( | |
751 | cpfile, prev, prev_bh, kaddr); | |
752 | list->ssl_next = cpu_to_le64(next); | |
753 | kunmap_atomic(kaddr, KM_USER0); | |
754 | ||
755 | kaddr = kmap_atomic(cp_bh->b_page, KM_USER0); | |
756 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr); | |
757 | cp->cp_snapshot_list.ssl_next = cpu_to_le64(0); | |
758 | cp->cp_snapshot_list.ssl_prev = cpu_to_le64(0); | |
759 | nilfs_checkpoint_clear_snapshot(cp); | |
760 | kunmap_atomic(kaddr, KM_USER0); | |
761 | ||
762 | kaddr = kmap_atomic(header_bh->b_page, KM_USER0); | |
763 | header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr); | |
764 | le64_add_cpu(&header->ch_nsnapshots, -1); | |
765 | kunmap_atomic(kaddr, KM_USER0); | |
766 | ||
767 | nilfs_mdt_mark_buffer_dirty(next_bh); | |
768 | nilfs_mdt_mark_buffer_dirty(prev_bh); | |
769 | nilfs_mdt_mark_buffer_dirty(cp_bh); | |
770 | nilfs_mdt_mark_buffer_dirty(header_bh); | |
771 | nilfs_mdt_mark_dirty(cpfile); | |
772 | ||
773 | brelse(prev_bh); | |
774 | ||
775 | out_next: | |
776 | brelse(next_bh); | |
777 | ||
778 | out_header: | |
779 | brelse(header_bh); | |
780 | ||
781 | out_cp: | |
782 | brelse(cp_bh); | |
783 | ||
784 | out_sem: | |
785 | up_write(&NILFS_MDT(cpfile)->mi_sem); | |
786 | return ret; | |
787 | } | |
788 | ||
789 | /** | |
790 | * nilfs_cpfile_is_snapshot - | |
791 | * @cpfile: inode of checkpoint file | |
792 | * @cno: checkpoint number | |
793 | * | |
794 | * Description: | |
795 | * | |
796 | * Return Value: On success, 1 is returned if the checkpoint specified by | |
797 | * @cno is a snapshot, or 0 if not. On error, one of the following negative | |
798 | * error codes is returned. | |
799 | * | |
800 | * %-EIO - I/O error. | |
801 | * | |
802 | * %-ENOMEM - Insufficient amount of memory available. | |
803 | * | |
804 | * %-ENOENT - No such checkpoint. | |
805 | */ | |
806 | int nilfs_cpfile_is_snapshot(struct inode *cpfile, __u64 cno) | |
807 | { | |
808 | struct buffer_head *bh; | |
809 | struct nilfs_checkpoint *cp; | |
810 | void *kaddr; | |
811 | int ret; | |
812 | ||
813 | down_read(&NILFS_MDT(cpfile)->mi_sem); | |
814 | ||
815 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &bh); | |
816 | if (ret < 0) | |
817 | goto out; | |
818 | kaddr = kmap_atomic(bh->b_page, KM_USER0); | |
819 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr); | |
820 | ret = nilfs_checkpoint_snapshot(cp); | |
821 | kunmap_atomic(kaddr, KM_USER0); | |
822 | brelse(bh); | |
823 | ||
824 | out: | |
825 | up_read(&NILFS_MDT(cpfile)->mi_sem); | |
826 | return ret; | |
827 | } | |
828 | ||
829 | /** | |
830 | * nilfs_cpfile_change_cpmode - change checkpoint mode | |
831 | * @cpfile: inode of checkpoint file | |
832 | * @cno: checkpoint number | |
833 | * @status: mode of checkpoint | |
834 | * | |
835 | * Description: nilfs_change_cpmode() changes the mode of the checkpoint | |
836 | * specified by @cno. The mode @mode is NILFS_CHECKPOINT or NILFS_SNAPSHOT. | |
837 | * | |
838 | * Return Value: On success, 0 is returned. On error, one of the following | |
839 | * negative error codes is returned. | |
840 | * | |
841 | * %-EIO - I/O error. | |
842 | * | |
843 | * %-ENOMEM - Insufficient amount of memory available. | |
844 | * | |
845 | * %-ENOENT - No such checkpoint. | |
846 | */ | |
847 | int nilfs_cpfile_change_cpmode(struct inode *cpfile, __u64 cno, int mode) | |
848 | { | |
849 | struct the_nilfs *nilfs; | |
850 | int ret; | |
851 | ||
852 | nilfs = NILFS_MDT(cpfile)->mi_nilfs; | |
853 | ||
854 | switch (mode) { | |
855 | case NILFS_CHECKPOINT: | |
856 | /* | |
857 | * Check for protecting existing snapshot mounts: | |
858 | * bd_mount_sem is used to make this operation atomic and | |
859 | * exclusive with a new mount job. Though it doesn't cover | |
860 | * umount, it's enough for the purpose. | |
861 | */ | |
862 | down(&nilfs->ns_bdev->bd_mount_sem); | |
863 | if (nilfs_checkpoint_is_mounted(nilfs, cno, 1)) { | |
864 | /* Current implementation does not have to protect | |
865 | plain read-only mounts since they are exclusive | |
866 | with a read/write mount and are protected from the | |
867 | cleaner. */ | |
868 | ret = -EBUSY; | |
869 | } else | |
870 | ret = nilfs_cpfile_clear_snapshot(cpfile, cno); | |
871 | up(&nilfs->ns_bdev->bd_mount_sem); | |
872 | return ret; | |
873 | case NILFS_SNAPSHOT: | |
874 | return nilfs_cpfile_set_snapshot(cpfile, cno); | |
875 | default: | |
876 | return -EINVAL; | |
877 | } | |
878 | } | |
879 | ||
880 | /** | |
881 | * nilfs_cpfile_get_stat - get checkpoint statistics | |
882 | * @cpfile: inode of checkpoint file | |
883 | * @stat: pointer to a structure of checkpoint statistics | |
884 | * | |
885 | * Description: nilfs_cpfile_get_stat() returns information about checkpoints. | |
886 | * | |
887 | * Return Value: On success, 0 is returned, and checkpoints information is | |
888 | * stored in the place pointed by @stat. On error, one of the following | |
889 | * negative error codes is returned. | |
890 | * | |
891 | * %-EIO - I/O error. | |
892 | * | |
893 | * %-ENOMEM - Insufficient amount of memory available. | |
894 | */ | |
895 | int nilfs_cpfile_get_stat(struct inode *cpfile, struct nilfs_cpstat *cpstat) | |
896 | { | |
897 | struct buffer_head *bh; | |
898 | struct nilfs_cpfile_header *header; | |
899 | void *kaddr; | |
900 | int ret; | |
901 | ||
902 | down_read(&NILFS_MDT(cpfile)->mi_sem); | |
903 | ||
904 | ret = nilfs_cpfile_get_header_block(cpfile, &bh); | |
905 | if (ret < 0) | |
906 | goto out_sem; | |
907 | kaddr = kmap_atomic(bh->b_page, KM_USER0); | |
908 | header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr); | |
909 | cpstat->cs_cno = nilfs_mdt_cno(cpfile); | |
910 | cpstat->cs_ncps = le64_to_cpu(header->ch_ncheckpoints); | |
911 | cpstat->cs_nsss = le64_to_cpu(header->ch_nsnapshots); | |
912 | kunmap_atomic(kaddr, KM_USER0); | |
913 | brelse(bh); | |
914 | ||
915 | out_sem: | |
916 | up_read(&NILFS_MDT(cpfile)->mi_sem); | |
917 | return ret; | |
918 | } |