Commit | Line | Data |
---|---|---|
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 | ||
425 | static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 cno, | |
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; | |
431 | __u64 curr, next; | |
432 | unsigned long curr_blkoff, next_blkoff; | |
433 | void *kaddr; | |
434 | int n, ret; | |
435 | ||
436 | down_read(&NILFS_MDT(cpfile)->mi_sem); | |
437 | ||
438 | if (cno == 0) { | |
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 | } | |
451 | } else | |
452 | curr = cno; | |
453 | curr_blkoff = nilfs_cpfile_get_blkoff(cpfile, curr); | |
454 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, curr, 0, &bh); | |
455 | if (ret < 0) | |
456 | goto out; | |
457 | kaddr = kmap_atomic(bh->b_page, KM_USER0); | |
458 | for (n = 0; n < nci; n++) { | |
459 | cp = nilfs_cpfile_block_get_checkpoint( | |
460 | cpfile, curr, bh, kaddr); | |
461 | nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp, &ci[n]); | |
462 | next = le64_to_cpu(cp->cp_snapshot_list.ssl_next); | |
463 | if (next == 0) { | |
464 | curr = next; | |
465 | n++; | |
466 | break; | |
467 | } | |
468 | next_blkoff = nilfs_cpfile_get_blkoff(cpfile, next); | |
469 | if (curr_blkoff != next_blkoff) { | |
470 | kunmap_atomic(kaddr, KM_USER0); | |
471 | brelse(bh); | |
472 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, next, | |
473 | 0, &bh); | |
474 | if (ret < 0) | |
475 | goto out; | |
476 | kaddr = kmap_atomic(bh->b_page, KM_USER0); | |
477 | } | |
478 | curr = next; | |
479 | curr_blkoff = next_blkoff; | |
480 | } | |
481 | kunmap_atomic(kaddr, KM_USER0); | |
482 | brelse(bh); | |
483 | ret = n; | |
484 | ||
485 | out: | |
486 | up_read(&NILFS_MDT(cpfile)->mi_sem); | |
487 | return ret; | |
488 | } | |
489 | ||
490 | /** | |
491 | * nilfs_cpfile_get_cpinfo - | |
492 | * @cpfile: | |
493 | * @cno: | |
494 | * @ci: | |
495 | * @nci: | |
496 | */ | |
497 | ssize_t nilfs_cpfile_get_cpinfo(struct inode *cpfile, | |
498 | __u64 cno, int mode, | |
499 | struct nilfs_cpinfo *ci, size_t nci) | |
500 | { | |
501 | switch (mode) { | |
502 | case NILFS_CHECKPOINT: | |
503 | return nilfs_cpfile_do_get_cpinfo(cpfile, cno, ci, nci); | |
504 | case NILFS_SNAPSHOT: | |
505 | return nilfs_cpfile_do_get_ssinfo(cpfile, cno, ci, nci); | |
506 | default: | |
507 | return -EINVAL; | |
508 | } | |
509 | } | |
510 | ||
511 | /** | |
512 | * nilfs_cpfile_delete_checkpoint - | |
513 | * @cpfile: | |
514 | * @cno: | |
515 | */ | |
516 | int nilfs_cpfile_delete_checkpoint(struct inode *cpfile, __u64 cno) | |
517 | { | |
518 | struct nilfs_cpinfo ci; | |
519 | ssize_t nci; | |
520 | int ret; | |
521 | ||
522 | /* checkpoint number 0 is invalid */ | |
523 | if (cno == 0) | |
524 | return -ENOENT; | |
525 | nci = nilfs_cpfile_do_get_cpinfo(cpfile, cno, &ci, 1); | |
526 | if (nci < 0) | |
527 | return nci; | |
528 | else if (nci == 0 || ci.ci_cno != cno) | |
529 | return -ENOENT; | |
530 | ||
531 | /* cannot delete the latest checkpoint nor snapshots */ | |
532 | ret = nilfs_cpinfo_snapshot(&ci); | |
533 | if (ret < 0) | |
534 | return ret; | |
535 | else if (ret > 0 || cno == nilfs_mdt_cno(cpfile) - 1) | |
536 | return -EPERM; | |
537 | ||
538 | return nilfs_cpfile_delete_checkpoints(cpfile, cno, cno + 1); | |
539 | } | |
540 | ||
541 | static struct nilfs_snapshot_list * | |
542 | nilfs_cpfile_block_get_snapshot_list(const struct inode *cpfile, | |
543 | __u64 cno, | |
544 | struct buffer_head *bh, | |
545 | void *kaddr) | |
546 | { | |
547 | struct nilfs_cpfile_header *header; | |
548 | struct nilfs_checkpoint *cp; | |
549 | struct nilfs_snapshot_list *list; | |
550 | ||
551 | if (cno != 0) { | |
552 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr); | |
553 | list = &cp->cp_snapshot_list; | |
554 | } else { | |
555 | header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr); | |
556 | list = &header->ch_snapshot_list; | |
557 | } | |
558 | return list; | |
559 | } | |
560 | ||
561 | static int nilfs_cpfile_set_snapshot(struct inode *cpfile, __u64 cno) | |
562 | { | |
563 | struct buffer_head *header_bh, *curr_bh, *prev_bh, *cp_bh; | |
564 | struct nilfs_cpfile_header *header; | |
565 | struct nilfs_checkpoint *cp; | |
566 | struct nilfs_snapshot_list *list; | |
567 | __u64 curr, prev; | |
568 | unsigned long curr_blkoff, prev_blkoff; | |
569 | void *kaddr; | |
570 | int ret; | |
571 | ||
572 | down_write(&NILFS_MDT(cpfile)->mi_sem); | |
573 | ||
574 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh); | |
575 | if (ret < 0) | |
576 | goto out_sem; | |
577 | kaddr = kmap_atomic(cp_bh->b_page, KM_USER0); | |
578 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr); | |
579 | if (nilfs_checkpoint_invalid(cp)) { | |
580 | ret = -ENOENT; | |
581 | kunmap_atomic(kaddr, KM_USER0); | |
582 | goto out_cp; | |
583 | } | |
584 | if (nilfs_checkpoint_snapshot(cp)) { | |
585 | ret = 0; | |
586 | kunmap_atomic(kaddr, KM_USER0); | |
587 | goto out_cp; | |
588 | } | |
589 | kunmap_atomic(kaddr, KM_USER0); | |
590 | ||
591 | ret = nilfs_cpfile_get_header_block(cpfile, &header_bh); | |
592 | if (ret < 0) | |
593 | goto out_cp; | |
594 | kaddr = kmap_atomic(header_bh->b_page, KM_USER0); | |
595 | header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr); | |
596 | list = &header->ch_snapshot_list; | |
597 | curr_bh = header_bh; | |
598 | get_bh(curr_bh); | |
599 | curr = 0; | |
600 | curr_blkoff = 0; | |
601 | prev = le64_to_cpu(list->ssl_prev); | |
602 | while (prev > cno) { | |
603 | prev_blkoff = nilfs_cpfile_get_blkoff(cpfile, prev); | |
604 | curr = prev; | |
605 | if (curr_blkoff != prev_blkoff) { | |
606 | kunmap_atomic(kaddr, KM_USER0); | |
607 | brelse(curr_bh); | |
608 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, curr, | |
609 | 0, &curr_bh); | |
610 | if (ret < 0) | |
611 | goto out_header; | |
612 | kaddr = kmap_atomic(curr_bh->b_page, KM_USER0); | |
613 | } | |
614 | curr_blkoff = prev_blkoff; | |
615 | cp = nilfs_cpfile_block_get_checkpoint( | |
616 | cpfile, curr, curr_bh, kaddr); | |
617 | list = &cp->cp_snapshot_list; | |
618 | prev = le64_to_cpu(list->ssl_prev); | |
619 | } | |
620 | kunmap_atomic(kaddr, KM_USER0); | |
621 | ||
622 | if (prev != 0) { | |
623 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, prev, 0, | |
624 | &prev_bh); | |
625 | if (ret < 0) | |
626 | goto out_curr; | |
627 | } else { | |
628 | prev_bh = header_bh; | |
629 | get_bh(prev_bh); | |
630 | } | |
631 | ||
632 | kaddr = kmap_atomic(curr_bh->b_page, KM_USER0); | |
633 | list = nilfs_cpfile_block_get_snapshot_list( | |
634 | cpfile, curr, curr_bh, kaddr); | |
635 | list->ssl_prev = cpu_to_le64(cno); | |
636 | kunmap_atomic(kaddr, KM_USER0); | |
637 | ||
638 | kaddr = kmap_atomic(cp_bh->b_page, KM_USER0); | |
639 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr); | |
640 | cp->cp_snapshot_list.ssl_next = cpu_to_le64(curr); | |
641 | cp->cp_snapshot_list.ssl_prev = cpu_to_le64(prev); | |
642 | nilfs_checkpoint_set_snapshot(cp); | |
643 | kunmap_atomic(kaddr, KM_USER0); | |
644 | ||
645 | kaddr = kmap_atomic(prev_bh->b_page, KM_USER0); | |
646 | list = nilfs_cpfile_block_get_snapshot_list( | |
647 | cpfile, prev, prev_bh, kaddr); | |
648 | list->ssl_next = cpu_to_le64(cno); | |
649 | kunmap_atomic(kaddr, KM_USER0); | |
650 | ||
651 | kaddr = kmap_atomic(header_bh->b_page, KM_USER0); | |
652 | header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr); | |
653 | le64_add_cpu(&header->ch_nsnapshots, 1); | |
654 | kunmap_atomic(kaddr, KM_USER0); | |
655 | ||
656 | nilfs_mdt_mark_buffer_dirty(prev_bh); | |
657 | nilfs_mdt_mark_buffer_dirty(curr_bh); | |
658 | nilfs_mdt_mark_buffer_dirty(cp_bh); | |
659 | nilfs_mdt_mark_buffer_dirty(header_bh); | |
660 | nilfs_mdt_mark_dirty(cpfile); | |
661 | ||
662 | brelse(prev_bh); | |
663 | ||
664 | out_curr: | |
665 | brelse(curr_bh); | |
666 | ||
667 | out_header: | |
668 | brelse(header_bh); | |
669 | ||
670 | out_cp: | |
671 | brelse(cp_bh); | |
672 | ||
673 | out_sem: | |
674 | up_write(&NILFS_MDT(cpfile)->mi_sem); | |
675 | return ret; | |
676 | } | |
677 | ||
678 | static int nilfs_cpfile_clear_snapshot(struct inode *cpfile, __u64 cno) | |
679 | { | |
680 | struct buffer_head *header_bh, *next_bh, *prev_bh, *cp_bh; | |
681 | struct nilfs_cpfile_header *header; | |
682 | struct nilfs_checkpoint *cp; | |
683 | struct nilfs_snapshot_list *list; | |
684 | __u64 next, prev; | |
685 | void *kaddr; | |
686 | int ret; | |
687 | ||
688 | down_write(&NILFS_MDT(cpfile)->mi_sem); | |
689 | ||
690 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh); | |
691 | if (ret < 0) | |
692 | goto out_sem; | |
693 | kaddr = kmap_atomic(cp_bh->b_page, KM_USER0); | |
694 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr); | |
695 | if (nilfs_checkpoint_invalid(cp)) { | |
696 | ret = -ENOENT; | |
697 | kunmap_atomic(kaddr, KM_USER0); | |
698 | goto out_cp; | |
699 | } | |
700 | if (!nilfs_checkpoint_snapshot(cp)) { | |
701 | ret = 0; | |
702 | kunmap_atomic(kaddr, KM_USER0); | |
703 | goto out_cp; | |
704 | } | |
705 | ||
706 | list = &cp->cp_snapshot_list; | |
707 | next = le64_to_cpu(list->ssl_next); | |
708 | prev = le64_to_cpu(list->ssl_prev); | |
709 | kunmap_atomic(kaddr, KM_USER0); | |
710 | ||
711 | ret = nilfs_cpfile_get_header_block(cpfile, &header_bh); | |
712 | if (ret < 0) | |
713 | goto out_cp; | |
714 | if (next != 0) { | |
715 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, next, 0, | |
716 | &next_bh); | |
717 | if (ret < 0) | |
718 | goto out_header; | |
719 | } else { | |
720 | next_bh = header_bh; | |
721 | get_bh(next_bh); | |
722 | } | |
723 | if (prev != 0) { | |
724 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, prev, 0, | |
725 | &prev_bh); | |
726 | if (ret < 0) | |
727 | goto out_next; | |
728 | } else { | |
729 | prev_bh = header_bh; | |
730 | get_bh(prev_bh); | |
731 | } | |
732 | ||
733 | kaddr = kmap_atomic(next_bh->b_page, KM_USER0); | |
734 | list = nilfs_cpfile_block_get_snapshot_list( | |
735 | cpfile, next, next_bh, kaddr); | |
736 | list->ssl_prev = cpu_to_le64(prev); | |
737 | kunmap_atomic(kaddr, KM_USER0); | |
738 | ||
739 | kaddr = kmap_atomic(prev_bh->b_page, KM_USER0); | |
740 | list = nilfs_cpfile_block_get_snapshot_list( | |
741 | cpfile, prev, prev_bh, kaddr); | |
742 | list->ssl_next = cpu_to_le64(next); | |
743 | kunmap_atomic(kaddr, KM_USER0); | |
744 | ||
745 | kaddr = kmap_atomic(cp_bh->b_page, KM_USER0); | |
746 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr); | |
747 | cp->cp_snapshot_list.ssl_next = cpu_to_le64(0); | |
748 | cp->cp_snapshot_list.ssl_prev = cpu_to_le64(0); | |
749 | nilfs_checkpoint_clear_snapshot(cp); | |
750 | kunmap_atomic(kaddr, KM_USER0); | |
751 | ||
752 | kaddr = kmap_atomic(header_bh->b_page, KM_USER0); | |
753 | header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr); | |
754 | le64_add_cpu(&header->ch_nsnapshots, -1); | |
755 | kunmap_atomic(kaddr, KM_USER0); | |
756 | ||
757 | nilfs_mdt_mark_buffer_dirty(next_bh); | |
758 | nilfs_mdt_mark_buffer_dirty(prev_bh); | |
759 | nilfs_mdt_mark_buffer_dirty(cp_bh); | |
760 | nilfs_mdt_mark_buffer_dirty(header_bh); | |
761 | nilfs_mdt_mark_dirty(cpfile); | |
762 | ||
763 | brelse(prev_bh); | |
764 | ||
765 | out_next: | |
766 | brelse(next_bh); | |
767 | ||
768 | out_header: | |
769 | brelse(header_bh); | |
770 | ||
771 | out_cp: | |
772 | brelse(cp_bh); | |
773 | ||
774 | out_sem: | |
775 | up_write(&NILFS_MDT(cpfile)->mi_sem); | |
776 | return ret; | |
777 | } | |
778 | ||
779 | /** | |
780 | * nilfs_cpfile_is_snapshot - | |
781 | * @cpfile: inode of checkpoint file | |
782 | * @cno: checkpoint number | |
783 | * | |
784 | * Description: | |
785 | * | |
786 | * Return Value: On success, 1 is returned if the checkpoint specified by | |
787 | * @cno is a snapshot, or 0 if not. On error, one of the following negative | |
788 | * error codes is returned. | |
789 | * | |
790 | * %-EIO - I/O error. | |
791 | * | |
792 | * %-ENOMEM - Insufficient amount of memory available. | |
793 | * | |
794 | * %-ENOENT - No such checkpoint. | |
795 | */ | |
796 | int nilfs_cpfile_is_snapshot(struct inode *cpfile, __u64 cno) | |
797 | { | |
798 | struct buffer_head *bh; | |
799 | struct nilfs_checkpoint *cp; | |
800 | void *kaddr; | |
801 | int ret; | |
802 | ||
803 | down_read(&NILFS_MDT(cpfile)->mi_sem); | |
804 | ||
805 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &bh); | |
806 | if (ret < 0) | |
807 | goto out; | |
808 | kaddr = kmap_atomic(bh->b_page, KM_USER0); | |
809 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr); | |
810 | ret = nilfs_checkpoint_snapshot(cp); | |
811 | kunmap_atomic(kaddr, KM_USER0); | |
812 | brelse(bh); | |
813 | ||
814 | out: | |
815 | up_read(&NILFS_MDT(cpfile)->mi_sem); | |
816 | return ret; | |
817 | } | |
818 | ||
819 | /** | |
820 | * nilfs_cpfile_change_cpmode - change checkpoint mode | |
821 | * @cpfile: inode of checkpoint file | |
822 | * @cno: checkpoint number | |
823 | * @status: mode of checkpoint | |
824 | * | |
825 | * Description: nilfs_change_cpmode() changes the mode of the checkpoint | |
826 | * specified by @cno. The mode @mode is NILFS_CHECKPOINT or NILFS_SNAPSHOT. | |
827 | * | |
828 | * Return Value: On success, 0 is returned. On error, one of the following | |
829 | * negative error codes is returned. | |
830 | * | |
831 | * %-EIO - I/O error. | |
832 | * | |
833 | * %-ENOMEM - Insufficient amount of memory available. | |
834 | * | |
835 | * %-ENOENT - No such checkpoint. | |
836 | */ | |
837 | int nilfs_cpfile_change_cpmode(struct inode *cpfile, __u64 cno, int mode) | |
838 | { | |
839 | struct the_nilfs *nilfs; | |
840 | int ret; | |
841 | ||
842 | nilfs = NILFS_MDT(cpfile)->mi_nilfs; | |
843 | ||
844 | switch (mode) { | |
845 | case NILFS_CHECKPOINT: | |
846 | /* | |
847 | * Check for protecting existing snapshot mounts: | |
848 | * bd_mount_sem is used to make this operation atomic and | |
849 | * exclusive with a new mount job. Though it doesn't cover | |
850 | * umount, it's enough for the purpose. | |
851 | */ | |
852 | down(&nilfs->ns_bdev->bd_mount_sem); | |
853 | if (nilfs_checkpoint_is_mounted(nilfs, cno, 1)) { | |
854 | /* Current implementation does not have to protect | |
855 | plain read-only mounts since they are exclusive | |
856 | with a read/write mount and are protected from the | |
857 | cleaner. */ | |
858 | ret = -EBUSY; | |
859 | } else | |
860 | ret = nilfs_cpfile_clear_snapshot(cpfile, cno); | |
861 | up(&nilfs->ns_bdev->bd_mount_sem); | |
862 | return ret; | |
863 | case NILFS_SNAPSHOT: | |
864 | return nilfs_cpfile_set_snapshot(cpfile, cno); | |
865 | default: | |
866 | return -EINVAL; | |
867 | } | |
868 | } | |
869 | ||
870 | /** | |
871 | * nilfs_cpfile_get_stat - get checkpoint statistics | |
872 | * @cpfile: inode of checkpoint file | |
873 | * @stat: pointer to a structure of checkpoint statistics | |
874 | * | |
875 | * Description: nilfs_cpfile_get_stat() returns information about checkpoints. | |
876 | * | |
877 | * Return Value: On success, 0 is returned, and checkpoints information is | |
878 | * stored in the place pointed by @stat. On error, one of the following | |
879 | * negative error codes is returned. | |
880 | * | |
881 | * %-EIO - I/O error. | |
882 | * | |
883 | * %-ENOMEM - Insufficient amount of memory available. | |
884 | */ | |
885 | int nilfs_cpfile_get_stat(struct inode *cpfile, struct nilfs_cpstat *cpstat) | |
886 | { | |
887 | struct buffer_head *bh; | |
888 | struct nilfs_cpfile_header *header; | |
889 | void *kaddr; | |
890 | int ret; | |
891 | ||
892 | down_read(&NILFS_MDT(cpfile)->mi_sem); | |
893 | ||
894 | ret = nilfs_cpfile_get_header_block(cpfile, &bh); | |
895 | if (ret < 0) | |
896 | goto out_sem; | |
897 | kaddr = kmap_atomic(bh->b_page, KM_USER0); | |
898 | header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr); | |
899 | cpstat->cs_cno = nilfs_mdt_cno(cpfile); | |
900 | cpstat->cs_ncps = le64_to_cpu(header->ch_ncheckpoints); | |
901 | cpstat->cs_nsss = le64_to_cpu(header->ch_nsnapshots); | |
902 | kunmap_atomic(kaddr, KM_USER0); | |
903 | brelse(bh); | |
904 | ||
905 | out_sem: | |
906 | up_read(&NILFS_MDT(cpfile)->mi_sem); | |
907 | return ret; | |
908 | } |