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 | { | |
1f5abe7e | 43 | __u64 tcno = cno + NILFS_MDT(cpfile)->mi_first_entry_offset - 1; |
29619809 KS |
44 | do_div(tcno, nilfs_cpfile_checkpoints_per_block(cpfile)); |
45 | return (unsigned long)tcno; | |
46 | } | |
47 | ||
48 | /* offset in block */ | |
49 | static unsigned long | |
50 | nilfs_cpfile_get_offset(const struct inode *cpfile, __u64 cno) | |
51 | { | |
52 | __u64 tcno = cno + NILFS_MDT(cpfile)->mi_first_entry_offset - 1; | |
53 | return do_div(tcno, nilfs_cpfile_checkpoints_per_block(cpfile)); | |
54 | } | |
55 | ||
56 | static unsigned long | |
57 | nilfs_cpfile_checkpoints_in_block(const struct inode *cpfile, | |
58 | __u64 curr, | |
59 | __u64 max) | |
60 | { | |
61 | return min_t(__u64, | |
62 | nilfs_cpfile_checkpoints_per_block(cpfile) - | |
63 | nilfs_cpfile_get_offset(cpfile, curr), | |
64 | max - curr); | |
65 | } | |
66 | ||
67 | static inline int nilfs_cpfile_is_in_first(const struct inode *cpfile, | |
68 | __u64 cno) | |
69 | { | |
70 | return nilfs_cpfile_get_blkoff(cpfile, cno) == 0; | |
71 | } | |
72 | ||
73 | static unsigned int | |
74 | nilfs_cpfile_block_add_valid_checkpoints(const struct inode *cpfile, | |
75 | struct buffer_head *bh, | |
76 | void *kaddr, | |
77 | unsigned int n) | |
78 | { | |
79 | struct nilfs_checkpoint *cp = kaddr + bh_offset(bh); | |
80 | unsigned int count; | |
81 | ||
82 | count = le32_to_cpu(cp->cp_checkpoints_count) + n; | |
83 | cp->cp_checkpoints_count = cpu_to_le32(count); | |
84 | return count; | |
85 | } | |
86 | ||
87 | static unsigned int | |
88 | nilfs_cpfile_block_sub_valid_checkpoints(const struct inode *cpfile, | |
89 | struct buffer_head *bh, | |
90 | void *kaddr, | |
91 | unsigned int n) | |
92 | { | |
93 | struct nilfs_checkpoint *cp = kaddr + bh_offset(bh); | |
94 | unsigned int count; | |
95 | ||
1f5abe7e | 96 | WARN_ON(le32_to_cpu(cp->cp_checkpoints_count) < n); |
29619809 KS |
97 | count = le32_to_cpu(cp->cp_checkpoints_count) - n; |
98 | cp->cp_checkpoints_count = cpu_to_le32(count); | |
99 | return count; | |
100 | } | |
101 | ||
102 | static inline struct nilfs_cpfile_header * | |
103 | nilfs_cpfile_block_get_header(const struct inode *cpfile, | |
104 | struct buffer_head *bh, | |
105 | void *kaddr) | |
106 | { | |
107 | return kaddr + bh_offset(bh); | |
108 | } | |
109 | ||
110 | static struct nilfs_checkpoint * | |
111 | nilfs_cpfile_block_get_checkpoint(const struct inode *cpfile, __u64 cno, | |
112 | struct buffer_head *bh, | |
113 | void *kaddr) | |
114 | { | |
115 | return kaddr + bh_offset(bh) + nilfs_cpfile_get_offset(cpfile, cno) * | |
116 | NILFS_MDT(cpfile)->mi_entry_size; | |
117 | } | |
118 | ||
119 | static void nilfs_cpfile_block_init(struct inode *cpfile, | |
120 | struct buffer_head *bh, | |
121 | void *kaddr) | |
122 | { | |
123 | struct nilfs_checkpoint *cp = kaddr + bh_offset(bh); | |
124 | size_t cpsz = NILFS_MDT(cpfile)->mi_entry_size; | |
125 | int n = nilfs_cpfile_checkpoints_per_block(cpfile); | |
126 | ||
127 | while (n-- > 0) { | |
128 | nilfs_checkpoint_set_invalid(cp); | |
129 | cp = (void *)cp + cpsz; | |
130 | } | |
131 | } | |
132 | ||
133 | static inline int nilfs_cpfile_get_header_block(struct inode *cpfile, | |
134 | struct buffer_head **bhp) | |
135 | { | |
136 | return nilfs_mdt_get_block(cpfile, 0, 0, NULL, bhp); | |
137 | } | |
138 | ||
139 | static inline int nilfs_cpfile_get_checkpoint_block(struct inode *cpfile, | |
140 | __u64 cno, | |
141 | int create, | |
142 | struct buffer_head **bhp) | |
143 | { | |
144 | return nilfs_mdt_get_block(cpfile, | |
145 | nilfs_cpfile_get_blkoff(cpfile, cno), | |
146 | create, nilfs_cpfile_block_init, bhp); | |
147 | } | |
148 | ||
149 | static inline int nilfs_cpfile_delete_checkpoint_block(struct inode *cpfile, | |
150 | __u64 cno) | |
151 | { | |
152 | return nilfs_mdt_delete_block(cpfile, | |
153 | nilfs_cpfile_get_blkoff(cpfile, cno)); | |
154 | } | |
155 | ||
156 | /** | |
157 | * nilfs_cpfile_get_checkpoint - get a checkpoint | |
158 | * @cpfile: inode of checkpoint file | |
159 | * @cno: checkpoint number | |
160 | * @create: create flag | |
161 | * @cpp: pointer to a checkpoint | |
162 | * @bhp: pointer to a buffer head | |
163 | * | |
164 | * Description: nilfs_cpfile_get_checkpoint() acquires the checkpoint | |
165 | * specified by @cno. A new checkpoint will be created if @cno is the current | |
166 | * checkpoint number and @create is nonzero. | |
167 | * | |
168 | * Return Value: On success, 0 is returned, and the checkpoint and the | |
169 | * buffer head of the buffer on which the checkpoint is located are stored in | |
170 | * the place pointed by @cpp and @bhp, respectively. On error, one of the | |
171 | * following negative error codes is returned. | |
172 | * | |
173 | * %-EIO - I/O error. | |
174 | * | |
175 | * %-ENOMEM - Insufficient amount of memory available. | |
176 | * | |
177 | * %-ENOENT - No such checkpoint. | |
1f5abe7e RK |
178 | * |
179 | * %-EINVAL - invalid checkpoint. | |
29619809 KS |
180 | */ |
181 | int nilfs_cpfile_get_checkpoint(struct inode *cpfile, | |
182 | __u64 cno, | |
183 | int create, | |
184 | struct nilfs_checkpoint **cpp, | |
185 | struct buffer_head **bhp) | |
186 | { | |
187 | struct buffer_head *header_bh, *cp_bh; | |
188 | struct nilfs_cpfile_header *header; | |
189 | struct nilfs_checkpoint *cp; | |
190 | void *kaddr; | |
191 | int ret; | |
192 | ||
1f5abe7e RK |
193 | if (unlikely(cno < 1 || cno > nilfs_mdt_cno(cpfile) || |
194 | (cno < nilfs_mdt_cno(cpfile) && create))) | |
195 | return -EINVAL; | |
29619809 KS |
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 | ||
1f5abe7e RK |
291 | if (unlikely(start == 0 || start > end)) { |
292 | printk(KERN_ERR "%s: invalid range of checkpoint numbers: " | |
293 | "[%llu, %llu)\n", __func__, | |
294 | (unsigned long long)start, (unsigned long long)end); | |
295 | return -EINVAL; | |
29619809 KS |
296 | } |
297 | ||
298 | /* cannot delete the latest checkpoint */ | |
299 | if (start == nilfs_mdt_cno(cpfile) - 1) | |
300 | return -EPERM; | |
301 | ||
302 | down_write(&NILFS_MDT(cpfile)->mi_sem); | |
303 | ||
304 | ret = nilfs_cpfile_get_header_block(cpfile, &header_bh); | |
305 | if (ret < 0) | |
306 | goto out_sem; | |
307 | tnicps = 0; | |
308 | ||
309 | for (cno = start; cno < end; cno += ncps) { | |
310 | ncps = nilfs_cpfile_checkpoints_in_block(cpfile, cno, end); | |
311 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh); | |
312 | if (ret < 0) { | |
313 | if (ret != -ENOENT) | |
62013ab5 | 314 | goto out_header; |
29619809 KS |
315 | /* skip hole */ |
316 | ret = 0; | |
317 | continue; | |
318 | } | |
319 | ||
320 | kaddr = kmap_atomic(cp_bh->b_page, KM_USER0); | |
321 | cp = nilfs_cpfile_block_get_checkpoint( | |
322 | cpfile, cno, cp_bh, kaddr); | |
323 | nicps = 0; | |
324 | for (i = 0; i < ncps; i++, cp = (void *)cp + cpsz) { | |
1f5abe7e | 325 | WARN_ON(nilfs_checkpoint_snapshot(cp)); |
29619809 KS |
326 | if (!nilfs_checkpoint_invalid(cp)) { |
327 | nilfs_checkpoint_set_invalid(cp); | |
328 | nicps++; | |
329 | } | |
330 | } | |
331 | if (nicps > 0) { | |
332 | tnicps += nicps; | |
333 | nilfs_mdt_mark_buffer_dirty(cp_bh); | |
334 | nilfs_mdt_mark_dirty(cpfile); | |
335 | if (!nilfs_cpfile_is_in_first(cpfile, cno) && | |
336 | (count = nilfs_cpfile_block_sub_valid_checkpoints( | |
337 | cpfile, cp_bh, kaddr, nicps)) == 0) { | |
338 | /* make hole */ | |
339 | kunmap_atomic(kaddr, KM_USER0); | |
340 | brelse(cp_bh); | |
341 | ret = nilfs_cpfile_delete_checkpoint_block( | |
342 | cpfile, cno); | |
343 | if (ret == 0) | |
344 | continue; | |
345 | printk(KERN_ERR "%s: cannot delete block\n", | |
346 | __func__); | |
62013ab5 | 347 | goto out_header; |
29619809 KS |
348 | } |
349 | } | |
350 | ||
351 | kunmap_atomic(kaddr, KM_USER0); | |
352 | brelse(cp_bh); | |
353 | } | |
354 | ||
355 | if (tnicps > 0) { | |
356 | kaddr = kmap_atomic(header_bh->b_page, KM_USER0); | |
357 | header = nilfs_cpfile_block_get_header(cpfile, header_bh, | |
358 | kaddr); | |
6c98cd4e | 359 | le64_add_cpu(&header->ch_ncheckpoints, -(u64)tnicps); |
29619809 KS |
360 | nilfs_mdt_mark_buffer_dirty(header_bh); |
361 | nilfs_mdt_mark_dirty(cpfile); | |
362 | kunmap_atomic(kaddr, KM_USER0); | |
363 | } | |
62013ab5 RK |
364 | |
365 | out_header: | |
29619809 KS |
366 | brelse(header_bh); |
367 | ||
368 | out_sem: | |
369 | up_write(&NILFS_MDT(cpfile)->mi_sem); | |
370 | return ret; | |
371 | } | |
372 | ||
373 | static void nilfs_cpfile_checkpoint_to_cpinfo(struct inode *cpfile, | |
374 | struct nilfs_checkpoint *cp, | |
375 | struct nilfs_cpinfo *ci) | |
376 | { | |
377 | ci->ci_flags = le32_to_cpu(cp->cp_flags); | |
378 | ci->ci_cno = le64_to_cpu(cp->cp_cno); | |
379 | ci->ci_create = le64_to_cpu(cp->cp_create); | |
380 | ci->ci_nblk_inc = le64_to_cpu(cp->cp_nblk_inc); | |
381 | ci->ci_inodes_count = le64_to_cpu(cp->cp_inodes_count); | |
382 | ci->ci_blocks_count = le64_to_cpu(cp->cp_blocks_count); | |
383 | ci->ci_next = le64_to_cpu(cp->cp_snapshot_list.ssl_next); | |
384 | } | |
385 | ||
76068c4f | 386 | static ssize_t nilfs_cpfile_do_get_cpinfo(struct inode *cpfile, __u64 *cnop, |
003ff182 | 387 | void *buf, unsigned cisz, size_t nci) |
29619809 KS |
388 | { |
389 | struct nilfs_checkpoint *cp; | |
003ff182 | 390 | struct nilfs_cpinfo *ci = buf; |
29619809 KS |
391 | struct buffer_head *bh; |
392 | size_t cpsz = NILFS_MDT(cpfile)->mi_entry_size; | |
76068c4f | 393 | __u64 cur_cno = nilfs_mdt_cno(cpfile), cno = *cnop; |
29619809 KS |
394 | void *kaddr; |
395 | int n, ret; | |
396 | int ncps, i; | |
397 | ||
1f5abe7e RK |
398 | if (cno == 0) |
399 | return -ENOENT; /* checkpoint number 0 is invalid */ | |
29619809 KS |
400 | down_read(&NILFS_MDT(cpfile)->mi_sem); |
401 | ||
402 | for (n = 0; cno < cur_cno && n < nci; cno += ncps) { | |
403 | ncps = nilfs_cpfile_checkpoints_in_block(cpfile, cno, cur_cno); | |
404 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &bh); | |
405 | if (ret < 0) { | |
406 | if (ret != -ENOENT) | |
407 | goto out; | |
408 | continue; /* skip hole */ | |
409 | } | |
410 | ||
411 | kaddr = kmap_atomic(bh->b_page, KM_USER0); | |
412 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr); | |
413 | for (i = 0; i < ncps && n < nci; i++, cp = (void *)cp + cpsz) { | |
003ff182 RK |
414 | if (!nilfs_checkpoint_invalid(cp)) { |
415 | nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp, | |
416 | ci); | |
417 | ci = (void *)ci + cisz; | |
418 | n++; | |
419 | } | |
29619809 KS |
420 | } |
421 | kunmap_atomic(kaddr, KM_USER0); | |
422 | brelse(bh); | |
423 | } | |
424 | ||
425 | ret = n; | |
003ff182 RK |
426 | if (n > 0) { |
427 | ci = (void *)ci - cisz; | |
428 | *cnop = ci->ci_cno + 1; | |
429 | } | |
29619809 KS |
430 | |
431 | out: | |
432 | up_read(&NILFS_MDT(cpfile)->mi_sem); | |
433 | return ret; | |
434 | } | |
435 | ||
b028fcfc | 436 | static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 *cnop, |
003ff182 | 437 | void *buf, unsigned cisz, size_t nci) |
29619809 KS |
438 | { |
439 | struct buffer_head *bh; | |
440 | struct nilfs_cpfile_header *header; | |
441 | struct nilfs_checkpoint *cp; | |
003ff182 | 442 | struct nilfs_cpinfo *ci = buf; |
b028fcfc | 443 | __u64 curr = *cnop, next; |
29619809 KS |
444 | unsigned long curr_blkoff, next_blkoff; |
445 | void *kaddr; | |
7fa10d20 | 446 | int n = 0, ret; |
29619809 KS |
447 | |
448 | down_read(&NILFS_MDT(cpfile)->mi_sem); | |
449 | ||
b028fcfc | 450 | if (curr == 0) { |
29619809 KS |
451 | ret = nilfs_cpfile_get_header_block(cpfile, &bh); |
452 | if (ret < 0) | |
453 | goto out; | |
454 | kaddr = kmap_atomic(bh->b_page, KM_USER0); | |
455 | header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr); | |
456 | curr = le64_to_cpu(header->ch_snapshot_list.ssl_next); | |
457 | kunmap_atomic(kaddr, KM_USER0); | |
458 | brelse(bh); | |
459 | if (curr == 0) { | |
460 | ret = 0; | |
461 | goto out; | |
462 | } | |
b028fcfc RK |
463 | } else if (unlikely(curr == ~(__u64)0)) { |
464 | ret = 0; | |
465 | goto out; | |
466 | } | |
467 | ||
29619809 KS |
468 | curr_blkoff = nilfs_cpfile_get_blkoff(cpfile, curr); |
469 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, curr, 0, &bh); | |
7fa10d20 RK |
470 | if (unlikely(ret < 0)) { |
471 | if (ret == -ENOENT) | |
472 | ret = 0; /* No snapshots (started from a hole block) */ | |
29619809 | 473 | goto out; |
7fa10d20 | 474 | } |
29619809 | 475 | kaddr = kmap_atomic(bh->b_page, KM_USER0); |
7fa10d20 RK |
476 | while (n < nci) { |
477 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, curr, bh, kaddr); | |
478 | curr = ~(__u64)0; /* Terminator */ | |
479 | if (unlikely(nilfs_checkpoint_invalid(cp) || | |
480 | !nilfs_checkpoint_snapshot(cp))) | |
29619809 | 481 | break; |
003ff182 RK |
482 | nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp, ci); |
483 | ci = (void *)ci + cisz; | |
484 | n++; | |
7fa10d20 RK |
485 | next = le64_to_cpu(cp->cp_snapshot_list.ssl_next); |
486 | if (next == 0) | |
487 | break; /* reach end of the snapshot list */ | |
488 | ||
29619809 KS |
489 | next_blkoff = nilfs_cpfile_get_blkoff(cpfile, next); |
490 | if (curr_blkoff != next_blkoff) { | |
491 | kunmap_atomic(kaddr, KM_USER0); | |
492 | brelse(bh); | |
493 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, next, | |
494 | 0, &bh); | |
7fa10d20 RK |
495 | if (unlikely(ret < 0)) { |
496 | WARN_ON(ret == -ENOENT); | |
29619809 | 497 | goto out; |
7fa10d20 | 498 | } |
29619809 KS |
499 | kaddr = kmap_atomic(bh->b_page, KM_USER0); |
500 | } | |
501 | curr = next; | |
502 | curr_blkoff = next_blkoff; | |
503 | } | |
504 | kunmap_atomic(kaddr, KM_USER0); | |
505 | brelse(bh); | |
b028fcfc | 506 | *cnop = curr; |
29619809 KS |
507 | ret = n; |
508 | ||
509 | out: | |
510 | up_read(&NILFS_MDT(cpfile)->mi_sem); | |
511 | return ret; | |
512 | } | |
513 | ||
514 | /** | |
515 | * nilfs_cpfile_get_cpinfo - | |
516 | * @cpfile: | |
517 | * @cno: | |
518 | * @ci: | |
519 | * @nci: | |
520 | */ | |
b028fcfc RK |
521 | |
522 | ssize_t nilfs_cpfile_get_cpinfo(struct inode *cpfile, __u64 *cnop, int mode, | |
003ff182 | 523 | void *buf, unsigned cisz, size_t nci) |
29619809 KS |
524 | { |
525 | switch (mode) { | |
526 | case NILFS_CHECKPOINT: | |
003ff182 | 527 | return nilfs_cpfile_do_get_cpinfo(cpfile, cnop, buf, cisz, nci); |
29619809 | 528 | case NILFS_SNAPSHOT: |
003ff182 | 529 | return nilfs_cpfile_do_get_ssinfo(cpfile, cnop, buf, cisz, nci); |
29619809 KS |
530 | default: |
531 | return -EINVAL; | |
532 | } | |
533 | } | |
534 | ||
535 | /** | |
536 | * nilfs_cpfile_delete_checkpoint - | |
537 | * @cpfile: | |
538 | * @cno: | |
539 | */ | |
540 | int nilfs_cpfile_delete_checkpoint(struct inode *cpfile, __u64 cno) | |
541 | { | |
542 | struct nilfs_cpinfo ci; | |
76068c4f | 543 | __u64 tcno = cno; |
29619809 KS |
544 | ssize_t nci; |
545 | int ret; | |
546 | ||
003ff182 | 547 | nci = nilfs_cpfile_do_get_cpinfo(cpfile, &tcno, &ci, sizeof(ci), 1); |
29619809 KS |
548 | if (nci < 0) |
549 | return nci; | |
550 | else if (nci == 0 || ci.ci_cno != cno) | |
551 | return -ENOENT; | |
552 | ||
553 | /* cannot delete the latest checkpoint nor snapshots */ | |
554 | ret = nilfs_cpinfo_snapshot(&ci); | |
555 | if (ret < 0) | |
556 | return ret; | |
557 | else if (ret > 0 || cno == nilfs_mdt_cno(cpfile) - 1) | |
558 | return -EPERM; | |
559 | ||
560 | return nilfs_cpfile_delete_checkpoints(cpfile, cno, cno + 1); | |
561 | } | |
562 | ||
563 | static struct nilfs_snapshot_list * | |
564 | nilfs_cpfile_block_get_snapshot_list(const struct inode *cpfile, | |
565 | __u64 cno, | |
566 | struct buffer_head *bh, | |
567 | void *kaddr) | |
568 | { | |
569 | struct nilfs_cpfile_header *header; | |
570 | struct nilfs_checkpoint *cp; | |
571 | struct nilfs_snapshot_list *list; | |
572 | ||
573 | if (cno != 0) { | |
574 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr); | |
575 | list = &cp->cp_snapshot_list; | |
576 | } else { | |
577 | header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr); | |
578 | list = &header->ch_snapshot_list; | |
579 | } | |
580 | return list; | |
581 | } | |
582 | ||
583 | static int nilfs_cpfile_set_snapshot(struct inode *cpfile, __u64 cno) | |
584 | { | |
585 | struct buffer_head *header_bh, *curr_bh, *prev_bh, *cp_bh; | |
586 | struct nilfs_cpfile_header *header; | |
587 | struct nilfs_checkpoint *cp; | |
588 | struct nilfs_snapshot_list *list; | |
589 | __u64 curr, prev; | |
590 | unsigned long curr_blkoff, prev_blkoff; | |
591 | void *kaddr; | |
592 | int ret; | |
593 | ||
1f5abe7e RK |
594 | if (cno == 0) |
595 | return -ENOENT; /* checkpoint number 0 is invalid */ | |
29619809 KS |
596 | down_write(&NILFS_MDT(cpfile)->mi_sem); |
597 | ||
598 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh); | |
599 | if (ret < 0) | |
600 | goto out_sem; | |
601 | kaddr = kmap_atomic(cp_bh->b_page, KM_USER0); | |
602 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr); | |
603 | if (nilfs_checkpoint_invalid(cp)) { | |
604 | ret = -ENOENT; | |
605 | kunmap_atomic(kaddr, KM_USER0); | |
606 | goto out_cp; | |
607 | } | |
608 | if (nilfs_checkpoint_snapshot(cp)) { | |
609 | ret = 0; | |
610 | kunmap_atomic(kaddr, KM_USER0); | |
611 | goto out_cp; | |
612 | } | |
613 | kunmap_atomic(kaddr, KM_USER0); | |
614 | ||
615 | ret = nilfs_cpfile_get_header_block(cpfile, &header_bh); | |
616 | if (ret < 0) | |
617 | goto out_cp; | |
618 | kaddr = kmap_atomic(header_bh->b_page, KM_USER0); | |
619 | header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr); | |
620 | list = &header->ch_snapshot_list; | |
621 | curr_bh = header_bh; | |
622 | get_bh(curr_bh); | |
623 | curr = 0; | |
624 | curr_blkoff = 0; | |
625 | prev = le64_to_cpu(list->ssl_prev); | |
626 | while (prev > cno) { | |
627 | prev_blkoff = nilfs_cpfile_get_blkoff(cpfile, prev); | |
628 | curr = prev; | |
629 | if (curr_blkoff != prev_blkoff) { | |
630 | kunmap_atomic(kaddr, KM_USER0); | |
631 | brelse(curr_bh); | |
632 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, curr, | |
633 | 0, &curr_bh); | |
634 | if (ret < 0) | |
635 | goto out_header; | |
636 | kaddr = kmap_atomic(curr_bh->b_page, KM_USER0); | |
637 | } | |
638 | curr_blkoff = prev_blkoff; | |
639 | cp = nilfs_cpfile_block_get_checkpoint( | |
640 | cpfile, curr, curr_bh, kaddr); | |
641 | list = &cp->cp_snapshot_list; | |
642 | prev = le64_to_cpu(list->ssl_prev); | |
643 | } | |
644 | kunmap_atomic(kaddr, KM_USER0); | |
645 | ||
646 | if (prev != 0) { | |
647 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, prev, 0, | |
648 | &prev_bh); | |
649 | if (ret < 0) | |
650 | goto out_curr; | |
651 | } else { | |
652 | prev_bh = header_bh; | |
653 | get_bh(prev_bh); | |
654 | } | |
655 | ||
656 | kaddr = kmap_atomic(curr_bh->b_page, KM_USER0); | |
657 | list = nilfs_cpfile_block_get_snapshot_list( | |
658 | cpfile, curr, curr_bh, kaddr); | |
659 | list->ssl_prev = cpu_to_le64(cno); | |
660 | kunmap_atomic(kaddr, KM_USER0); | |
661 | ||
662 | kaddr = kmap_atomic(cp_bh->b_page, KM_USER0); | |
663 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr); | |
664 | cp->cp_snapshot_list.ssl_next = cpu_to_le64(curr); | |
665 | cp->cp_snapshot_list.ssl_prev = cpu_to_le64(prev); | |
666 | nilfs_checkpoint_set_snapshot(cp); | |
667 | kunmap_atomic(kaddr, KM_USER0); | |
668 | ||
669 | kaddr = kmap_atomic(prev_bh->b_page, KM_USER0); | |
670 | list = nilfs_cpfile_block_get_snapshot_list( | |
671 | cpfile, prev, prev_bh, kaddr); | |
672 | list->ssl_next = cpu_to_le64(cno); | |
673 | kunmap_atomic(kaddr, KM_USER0); | |
674 | ||
675 | kaddr = kmap_atomic(header_bh->b_page, KM_USER0); | |
676 | header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr); | |
677 | le64_add_cpu(&header->ch_nsnapshots, 1); | |
678 | kunmap_atomic(kaddr, KM_USER0); | |
679 | ||
680 | nilfs_mdt_mark_buffer_dirty(prev_bh); | |
681 | nilfs_mdt_mark_buffer_dirty(curr_bh); | |
682 | nilfs_mdt_mark_buffer_dirty(cp_bh); | |
683 | nilfs_mdt_mark_buffer_dirty(header_bh); | |
684 | nilfs_mdt_mark_dirty(cpfile); | |
685 | ||
686 | brelse(prev_bh); | |
687 | ||
688 | out_curr: | |
689 | brelse(curr_bh); | |
690 | ||
691 | out_header: | |
692 | brelse(header_bh); | |
693 | ||
694 | out_cp: | |
695 | brelse(cp_bh); | |
696 | ||
697 | out_sem: | |
698 | up_write(&NILFS_MDT(cpfile)->mi_sem); | |
699 | return ret; | |
700 | } | |
701 | ||
702 | static int nilfs_cpfile_clear_snapshot(struct inode *cpfile, __u64 cno) | |
703 | { | |
704 | struct buffer_head *header_bh, *next_bh, *prev_bh, *cp_bh; | |
705 | struct nilfs_cpfile_header *header; | |
706 | struct nilfs_checkpoint *cp; | |
707 | struct nilfs_snapshot_list *list; | |
708 | __u64 next, prev; | |
709 | void *kaddr; | |
710 | int ret; | |
711 | ||
1f5abe7e RK |
712 | if (cno == 0) |
713 | return -ENOENT; /* checkpoint number 0 is invalid */ | |
29619809 KS |
714 | down_write(&NILFS_MDT(cpfile)->mi_sem); |
715 | ||
716 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh); | |
717 | if (ret < 0) | |
718 | goto out_sem; | |
719 | kaddr = kmap_atomic(cp_bh->b_page, KM_USER0); | |
720 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr); | |
721 | if (nilfs_checkpoint_invalid(cp)) { | |
722 | ret = -ENOENT; | |
723 | kunmap_atomic(kaddr, KM_USER0); | |
724 | goto out_cp; | |
725 | } | |
726 | if (!nilfs_checkpoint_snapshot(cp)) { | |
727 | ret = 0; | |
728 | kunmap_atomic(kaddr, KM_USER0); | |
729 | goto out_cp; | |
730 | } | |
731 | ||
732 | list = &cp->cp_snapshot_list; | |
733 | next = le64_to_cpu(list->ssl_next); | |
734 | prev = le64_to_cpu(list->ssl_prev); | |
735 | kunmap_atomic(kaddr, KM_USER0); | |
736 | ||
737 | ret = nilfs_cpfile_get_header_block(cpfile, &header_bh); | |
738 | if (ret < 0) | |
739 | goto out_cp; | |
740 | if (next != 0) { | |
741 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, next, 0, | |
742 | &next_bh); | |
743 | if (ret < 0) | |
744 | goto out_header; | |
745 | } else { | |
746 | next_bh = header_bh; | |
747 | get_bh(next_bh); | |
748 | } | |
749 | if (prev != 0) { | |
750 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, prev, 0, | |
751 | &prev_bh); | |
752 | if (ret < 0) | |
753 | goto out_next; | |
754 | } else { | |
755 | prev_bh = header_bh; | |
756 | get_bh(prev_bh); | |
757 | } | |
758 | ||
759 | kaddr = kmap_atomic(next_bh->b_page, KM_USER0); | |
760 | list = nilfs_cpfile_block_get_snapshot_list( | |
761 | cpfile, next, next_bh, kaddr); | |
762 | list->ssl_prev = cpu_to_le64(prev); | |
763 | kunmap_atomic(kaddr, KM_USER0); | |
764 | ||
765 | kaddr = kmap_atomic(prev_bh->b_page, KM_USER0); | |
766 | list = nilfs_cpfile_block_get_snapshot_list( | |
767 | cpfile, prev, prev_bh, kaddr); | |
768 | list->ssl_next = cpu_to_le64(next); | |
769 | kunmap_atomic(kaddr, KM_USER0); | |
770 | ||
771 | kaddr = kmap_atomic(cp_bh->b_page, KM_USER0); | |
772 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr); | |
773 | cp->cp_snapshot_list.ssl_next = cpu_to_le64(0); | |
774 | cp->cp_snapshot_list.ssl_prev = cpu_to_le64(0); | |
775 | nilfs_checkpoint_clear_snapshot(cp); | |
776 | kunmap_atomic(kaddr, KM_USER0); | |
777 | ||
778 | kaddr = kmap_atomic(header_bh->b_page, KM_USER0); | |
779 | header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr); | |
780 | le64_add_cpu(&header->ch_nsnapshots, -1); | |
781 | kunmap_atomic(kaddr, KM_USER0); | |
782 | ||
783 | nilfs_mdt_mark_buffer_dirty(next_bh); | |
784 | nilfs_mdt_mark_buffer_dirty(prev_bh); | |
785 | nilfs_mdt_mark_buffer_dirty(cp_bh); | |
786 | nilfs_mdt_mark_buffer_dirty(header_bh); | |
787 | nilfs_mdt_mark_dirty(cpfile); | |
788 | ||
789 | brelse(prev_bh); | |
790 | ||
791 | out_next: | |
792 | brelse(next_bh); | |
793 | ||
794 | out_header: | |
795 | brelse(header_bh); | |
796 | ||
797 | out_cp: | |
798 | brelse(cp_bh); | |
799 | ||
800 | out_sem: | |
801 | up_write(&NILFS_MDT(cpfile)->mi_sem); | |
802 | return ret; | |
803 | } | |
804 | ||
805 | /** | |
806 | * nilfs_cpfile_is_snapshot - | |
807 | * @cpfile: inode of checkpoint file | |
808 | * @cno: checkpoint number | |
809 | * | |
810 | * Description: | |
811 | * | |
812 | * Return Value: On success, 1 is returned if the checkpoint specified by | |
813 | * @cno is a snapshot, or 0 if not. On error, one of the following negative | |
814 | * error codes is returned. | |
815 | * | |
816 | * %-EIO - I/O error. | |
817 | * | |
818 | * %-ENOMEM - Insufficient amount of memory available. | |
819 | * | |
820 | * %-ENOENT - No such checkpoint. | |
821 | */ | |
822 | int nilfs_cpfile_is_snapshot(struct inode *cpfile, __u64 cno) | |
823 | { | |
824 | struct buffer_head *bh; | |
825 | struct nilfs_checkpoint *cp; | |
826 | void *kaddr; | |
827 | int ret; | |
828 | ||
1f5abe7e RK |
829 | if (cno == 0) |
830 | return -ENOENT; /* checkpoint number 0 is invalid */ | |
29619809 KS |
831 | down_read(&NILFS_MDT(cpfile)->mi_sem); |
832 | ||
833 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &bh); | |
834 | if (ret < 0) | |
835 | goto out; | |
836 | kaddr = kmap_atomic(bh->b_page, KM_USER0); | |
837 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr); | |
838 | ret = nilfs_checkpoint_snapshot(cp); | |
839 | kunmap_atomic(kaddr, KM_USER0); | |
840 | brelse(bh); | |
841 | ||
842 | out: | |
843 | up_read(&NILFS_MDT(cpfile)->mi_sem); | |
844 | return ret; | |
845 | } | |
846 | ||
847 | /** | |
848 | * nilfs_cpfile_change_cpmode - change checkpoint mode | |
849 | * @cpfile: inode of checkpoint file | |
850 | * @cno: checkpoint number | |
851 | * @status: mode of checkpoint | |
852 | * | |
853 | * Description: nilfs_change_cpmode() changes the mode of the checkpoint | |
854 | * specified by @cno. The mode @mode is NILFS_CHECKPOINT or NILFS_SNAPSHOT. | |
855 | * | |
856 | * Return Value: On success, 0 is returned. On error, one of the following | |
857 | * negative error codes is returned. | |
858 | * | |
859 | * %-EIO - I/O error. | |
860 | * | |
861 | * %-ENOMEM - Insufficient amount of memory available. | |
862 | * | |
863 | * %-ENOENT - No such checkpoint. | |
864 | */ | |
865 | int nilfs_cpfile_change_cpmode(struct inode *cpfile, __u64 cno, int mode) | |
866 | { | |
867 | struct the_nilfs *nilfs; | |
868 | int ret; | |
869 | ||
870 | nilfs = NILFS_MDT(cpfile)->mi_nilfs; | |
871 | ||
872 | switch (mode) { | |
873 | case NILFS_CHECKPOINT: | |
874 | /* | |
875 | * Check for protecting existing snapshot mounts: | |
876 | * bd_mount_sem is used to make this operation atomic and | |
877 | * exclusive with a new mount job. Though it doesn't cover | |
878 | * umount, it's enough for the purpose. | |
879 | */ | |
880 | down(&nilfs->ns_bdev->bd_mount_sem); | |
881 | if (nilfs_checkpoint_is_mounted(nilfs, cno, 1)) { | |
882 | /* Current implementation does not have to protect | |
883 | plain read-only mounts since they are exclusive | |
884 | with a read/write mount and are protected from the | |
885 | cleaner. */ | |
886 | ret = -EBUSY; | |
887 | } else | |
888 | ret = nilfs_cpfile_clear_snapshot(cpfile, cno); | |
889 | up(&nilfs->ns_bdev->bd_mount_sem); | |
890 | return ret; | |
891 | case NILFS_SNAPSHOT: | |
892 | return nilfs_cpfile_set_snapshot(cpfile, cno); | |
893 | default: | |
894 | return -EINVAL; | |
895 | } | |
896 | } | |
897 | ||
898 | /** | |
899 | * nilfs_cpfile_get_stat - get checkpoint statistics | |
900 | * @cpfile: inode of checkpoint file | |
901 | * @stat: pointer to a structure of checkpoint statistics | |
902 | * | |
903 | * Description: nilfs_cpfile_get_stat() returns information about checkpoints. | |
904 | * | |
905 | * Return Value: On success, 0 is returned, and checkpoints information is | |
906 | * stored in the place pointed by @stat. On error, one of the following | |
907 | * negative error codes is returned. | |
908 | * | |
909 | * %-EIO - I/O error. | |
910 | * | |
911 | * %-ENOMEM - Insufficient amount of memory available. | |
912 | */ | |
913 | int nilfs_cpfile_get_stat(struct inode *cpfile, struct nilfs_cpstat *cpstat) | |
914 | { | |
915 | struct buffer_head *bh; | |
916 | struct nilfs_cpfile_header *header; | |
917 | void *kaddr; | |
918 | int ret; | |
919 | ||
920 | down_read(&NILFS_MDT(cpfile)->mi_sem); | |
921 | ||
922 | ret = nilfs_cpfile_get_header_block(cpfile, &bh); | |
923 | if (ret < 0) | |
924 | goto out_sem; | |
925 | kaddr = kmap_atomic(bh->b_page, KM_USER0); | |
926 | header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr); | |
927 | cpstat->cs_cno = nilfs_mdt_cno(cpfile); | |
928 | cpstat->cs_ncps = le64_to_cpu(header->ch_ncheckpoints); | |
929 | cpstat->cs_nsss = le64_to_cpu(header->ch_nsnapshots); | |
930 | kunmap_atomic(kaddr, KM_USER0); | |
931 | brelse(bh); | |
932 | ||
933 | out_sem: | |
934 | up_read(&NILFS_MDT(cpfile)->mi_sem); | |
935 | return ret; | |
936 | } |