1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | /* |
3 | * NILFS checkpoint file. |
4 | * |
5 | * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation. |
6 | * |
7 | * Written by Koji Sato. |
8 | */ |
9 | |
10 | #include <linux/kernel.h> |
11 | #include <linux/fs.h> |
12 | #include <linux/string.h> |
13 | #include <linux/buffer_head.h> |
14 | #include <linux/errno.h> |
15 | #include "mdt.h" |
16 | #include "cpfile.h" |
17 | |
18 | |
19 | static inline unsigned long |
20 | nilfs_cpfile_checkpoints_per_block(const struct inode *cpfile) |
21 | { |
22 | return NILFS_MDT(inode: cpfile)->mi_entries_per_block; |
23 | } |
24 | |
25 | /* block number from the beginning of the file */ |
26 | static unsigned long |
27 | nilfs_cpfile_get_blkoff(const struct inode *cpfile, __u64 cno) |
28 | { |
29 | __u64 tcno = cno + NILFS_MDT(inode: cpfile)->mi_first_entry_offset - 1; |
30 | |
31 | tcno = div64_ul(tcno, nilfs_cpfile_checkpoints_per_block(cpfile)); |
32 | return (unsigned long)tcno; |
33 | } |
34 | |
35 | /* offset in block */ |
36 | static unsigned long |
37 | nilfs_cpfile_get_offset(const struct inode *cpfile, __u64 cno) |
38 | { |
39 | __u64 tcno = cno + NILFS_MDT(inode: cpfile)->mi_first_entry_offset - 1; |
40 | |
41 | return do_div(tcno, nilfs_cpfile_checkpoints_per_block(cpfile)); |
42 | } |
43 | |
44 | static __u64 nilfs_cpfile_first_checkpoint_in_block(const struct inode *cpfile, |
45 | unsigned long blkoff) |
46 | { |
47 | return (__u64)nilfs_cpfile_checkpoints_per_block(cpfile) * blkoff |
48 | + 1 - NILFS_MDT(inode: cpfile)->mi_first_entry_offset; |
49 | } |
50 | |
51 | static unsigned long |
52 | nilfs_cpfile_checkpoints_in_block(const struct inode *cpfile, |
53 | __u64 curr, |
54 | __u64 max) |
55 | { |
56 | return min_t(__u64, |
57 | nilfs_cpfile_checkpoints_per_block(cpfile) - |
58 | nilfs_cpfile_get_offset(cpfile, curr), |
59 | max - curr); |
60 | } |
61 | |
62 | static inline int nilfs_cpfile_is_in_first(const struct inode *cpfile, |
63 | __u64 cno) |
64 | { |
65 | return nilfs_cpfile_get_blkoff(cpfile, cno) == 0; |
66 | } |
67 | |
68 | static unsigned int |
69 | nilfs_cpfile_block_add_valid_checkpoints(const struct inode *cpfile, |
70 | struct buffer_head *bh, |
71 | void *kaddr, |
72 | unsigned int n) |
73 | { |
74 | struct nilfs_checkpoint *cp = kaddr + bh_offset(bh); |
75 | unsigned int count; |
76 | |
77 | count = le32_to_cpu(cp->cp_checkpoints_count) + n; |
78 | cp->cp_checkpoints_count = cpu_to_le32(count); |
79 | return count; |
80 | } |
81 | |
82 | static unsigned int |
83 | nilfs_cpfile_block_sub_valid_checkpoints(const struct inode *cpfile, |
84 | struct buffer_head *bh, |
85 | void *kaddr, |
86 | unsigned int n) |
87 | { |
88 | struct nilfs_checkpoint *cp = kaddr + bh_offset(bh); |
89 | unsigned int count; |
90 | |
91 | WARN_ON(le32_to_cpu(cp->cp_checkpoints_count) < n); |
92 | count = le32_to_cpu(cp->cp_checkpoints_count) - n; |
93 | cp->cp_checkpoints_count = cpu_to_le32(count); |
94 | return count; |
95 | } |
96 | |
97 | static inline struct nilfs_cpfile_header * |
98 | (const struct inode *cpfile, |
99 | struct buffer_head *bh, |
100 | void *kaddr) |
101 | { |
102 | return kaddr + bh_offset(bh); |
103 | } |
104 | |
105 | static struct nilfs_checkpoint * |
106 | nilfs_cpfile_block_get_checkpoint(const struct inode *cpfile, __u64 cno, |
107 | struct buffer_head *bh, |
108 | void *kaddr) |
109 | { |
110 | return kaddr + bh_offset(bh) + nilfs_cpfile_get_offset(cpfile, cno) * |
111 | NILFS_MDT(inode: cpfile)->mi_entry_size; |
112 | } |
113 | |
114 | static void nilfs_cpfile_block_init(struct inode *cpfile, |
115 | struct buffer_head *bh, |
116 | void *kaddr) |
117 | { |
118 | struct nilfs_checkpoint *cp = kaddr + bh_offset(bh); |
119 | size_t cpsz = NILFS_MDT(inode: cpfile)->mi_entry_size; |
120 | int n = nilfs_cpfile_checkpoints_per_block(cpfile); |
121 | |
122 | while (n-- > 0) { |
123 | nilfs_checkpoint_set_invalid(cp); |
124 | cp = (void *)cp + cpsz; |
125 | } |
126 | } |
127 | |
128 | static inline int (struct inode *cpfile, |
129 | struct buffer_head **bhp) |
130 | { |
131 | return nilfs_mdt_get_block(cpfile, 0, 0, NULL, bhp); |
132 | } |
133 | |
134 | static inline int nilfs_cpfile_get_checkpoint_block(struct inode *cpfile, |
135 | __u64 cno, |
136 | int create, |
137 | struct buffer_head **bhp) |
138 | { |
139 | return nilfs_mdt_get_block(cpfile, |
140 | nilfs_cpfile_get_blkoff(cpfile, cno), |
141 | create, init_block: nilfs_cpfile_block_init, bhp); |
142 | } |
143 | |
144 | /** |
145 | * nilfs_cpfile_find_checkpoint_block - find and get a buffer on cpfile |
146 | * @cpfile: inode of cpfile |
147 | * @start_cno: start checkpoint number (inclusive) |
148 | * @end_cno: end checkpoint number (inclusive) |
149 | * @cnop: place to store the next checkpoint number |
150 | * @bhp: place to store a pointer to buffer_head struct |
151 | * |
152 | * Return Value: On success, it returns 0. On error, the following negative |
153 | * error code is returned. |
154 | * |
155 | * %-ENOMEM - Insufficient memory available. |
156 | * |
157 | * %-EIO - I/O error |
158 | * |
159 | * %-ENOENT - no block exists in the range. |
160 | */ |
161 | static int nilfs_cpfile_find_checkpoint_block(struct inode *cpfile, |
162 | __u64 start_cno, __u64 end_cno, |
163 | __u64 *cnop, |
164 | struct buffer_head **bhp) |
165 | { |
166 | unsigned long start, end, blkoff; |
167 | int ret; |
168 | |
169 | if (unlikely(start_cno > end_cno)) |
170 | return -ENOENT; |
171 | |
172 | start = nilfs_cpfile_get_blkoff(cpfile, cno: start_cno); |
173 | end = nilfs_cpfile_get_blkoff(cpfile, cno: end_cno); |
174 | |
175 | ret = nilfs_mdt_find_block(inode: cpfile, start, end, blkoff: &blkoff, out_bh: bhp); |
176 | if (!ret) |
177 | *cnop = (blkoff == start) ? start_cno : |
178 | nilfs_cpfile_first_checkpoint_in_block(cpfile, blkoff); |
179 | return ret; |
180 | } |
181 | |
182 | static inline int nilfs_cpfile_delete_checkpoint_block(struct inode *cpfile, |
183 | __u64 cno) |
184 | { |
185 | return nilfs_mdt_delete_block(cpfile, |
186 | nilfs_cpfile_get_blkoff(cpfile, cno)); |
187 | } |
188 | |
189 | /** |
190 | * nilfs_cpfile_read_checkpoint - read a checkpoint entry in cpfile |
191 | * @cpfile: checkpoint file inode |
192 | * @cno: number of checkpoint entry to read |
193 | * @root: nilfs root object |
194 | * @ifile: ifile's inode to read and attach to @root |
195 | * |
196 | * This function imports checkpoint information from the checkpoint file and |
197 | * stores it to the inode file given by @ifile and the nilfs root object |
198 | * given by @root. |
199 | * |
200 | * Return: 0 on success, or the following negative error code on failure. |
201 | * * %-EINVAL - Invalid checkpoint. |
202 | * * %-ENOMEM - Insufficient memory available. |
203 | * * %-EIO - I/O error (including metadata corruption). |
204 | */ |
205 | int nilfs_cpfile_read_checkpoint(struct inode *cpfile, __u64 cno, |
206 | struct nilfs_root *root, struct inode *ifile) |
207 | { |
208 | struct buffer_head *cp_bh; |
209 | struct nilfs_checkpoint *cp; |
210 | void *kaddr; |
211 | int ret; |
212 | |
213 | if (cno < 1 || cno > nilfs_mdt_cno(inode: cpfile)) |
214 | return -EINVAL; |
215 | |
216 | down_read(sem: &NILFS_MDT(inode: cpfile)->mi_sem); |
217 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, create: 0, bhp: &cp_bh); |
218 | if (unlikely(ret < 0)) { |
219 | if (ret == -ENOENT) |
220 | ret = -EINVAL; |
221 | goto out_sem; |
222 | } |
223 | |
224 | kaddr = kmap_local_page(page: cp_bh->b_page); |
225 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh: cp_bh, kaddr); |
226 | if (nilfs_checkpoint_invalid(cp)) { |
227 | ret = -EINVAL; |
228 | goto put_cp; |
229 | } |
230 | |
231 | ret = nilfs_read_inode_common(ifile, &cp->cp_ifile_inode); |
232 | if (unlikely(ret)) { |
233 | /* |
234 | * Since this inode is on a checkpoint entry, treat errors |
235 | * as metadata corruption. |
236 | */ |
237 | nilfs_err(cpfile->i_sb, |
238 | "ifile inode (checkpoint number=%llu) corrupted" , |
239 | (unsigned long long)cno); |
240 | ret = -EIO; |
241 | goto put_cp; |
242 | } |
243 | |
244 | /* Configure the nilfs root object */ |
245 | atomic64_set(v: &root->inodes_count, le64_to_cpu(cp->cp_inodes_count)); |
246 | atomic64_set(v: &root->blocks_count, le64_to_cpu(cp->cp_blocks_count)); |
247 | root->ifile = ifile; |
248 | |
249 | put_cp: |
250 | kunmap_local(kaddr); |
251 | brelse(bh: cp_bh); |
252 | out_sem: |
253 | up_read(sem: &NILFS_MDT(inode: cpfile)->mi_sem); |
254 | return ret; |
255 | } |
256 | |
257 | /** |
258 | * nilfs_cpfile_create_checkpoint - create a checkpoint entry on cpfile |
259 | * @cpfile: checkpoint file inode |
260 | * @cno: number of checkpoint to set up |
261 | * |
262 | * This function creates a checkpoint with the number specified by @cno on |
263 | * cpfile. If the specified checkpoint entry already exists due to a past |
264 | * failure, it will be reused without returning an error. |
265 | * In either case, the buffer of the block containing the checkpoint entry |
266 | * and the cpfile inode are made dirty for inclusion in the write log. |
267 | * |
268 | * Return: 0 on success, or the following negative error code on failure. |
269 | * * %-ENOMEM - Insufficient memory available. |
270 | * * %-EIO - I/O error (including metadata corruption). |
271 | * * %-EROFS - Read only filesystem |
272 | */ |
273 | int nilfs_cpfile_create_checkpoint(struct inode *cpfile, __u64 cno) |
274 | { |
275 | struct buffer_head *, *cp_bh; |
276 | struct nilfs_cpfile_header *; |
277 | struct nilfs_checkpoint *cp; |
278 | void *kaddr; |
279 | int ret; |
280 | |
281 | if (WARN_ON_ONCE(cno < 1)) |
282 | return -EIO; |
283 | |
284 | down_write(sem: &NILFS_MDT(inode: cpfile)->mi_sem); |
285 | ret = nilfs_cpfile_get_header_block(cpfile, bhp: &header_bh); |
286 | if (unlikely(ret < 0)) { |
287 | if (ret == -ENOENT) { |
288 | nilfs_error(cpfile->i_sb, |
289 | "checkpoint creation failed due to metadata corruption." ); |
290 | ret = -EIO; |
291 | } |
292 | goto out_sem; |
293 | } |
294 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, create: 1, bhp: &cp_bh); |
295 | if (unlikely(ret < 0)) |
296 | goto out_header; |
297 | |
298 | kaddr = kmap_local_page(page: cp_bh->b_page); |
299 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh: cp_bh, kaddr); |
300 | if (nilfs_checkpoint_invalid(cp)) { |
301 | /* a newly-created checkpoint */ |
302 | nilfs_checkpoint_clear_invalid(cp); |
303 | if (!nilfs_cpfile_is_in_first(cpfile, cno)) |
304 | nilfs_cpfile_block_add_valid_checkpoints(cpfile, bh: cp_bh, |
305 | kaddr, n: 1); |
306 | kunmap_local(kaddr); |
307 | |
308 | kaddr = kmap_local_page(page: header_bh->b_page); |
309 | header = nilfs_cpfile_block_get_header(cpfile, bh: header_bh, |
310 | kaddr); |
311 | le64_add_cpu(var: &header->ch_ncheckpoints, val: 1); |
312 | kunmap_local(kaddr); |
313 | mark_buffer_dirty(bh: header_bh); |
314 | } else { |
315 | kunmap_local(kaddr); |
316 | } |
317 | |
318 | /* Force the buffer and the inode to become dirty */ |
319 | mark_buffer_dirty(bh: cp_bh); |
320 | brelse(bh: cp_bh); |
321 | nilfs_mdt_mark_dirty(inode: cpfile); |
322 | |
323 | : |
324 | brelse(bh: header_bh); |
325 | |
326 | out_sem: |
327 | up_write(sem: &NILFS_MDT(inode: cpfile)->mi_sem); |
328 | return ret; |
329 | } |
330 | |
331 | /** |
332 | * nilfs_cpfile_finalize_checkpoint - fill in a checkpoint entry in cpfile |
333 | * @cpfile: checkpoint file inode |
334 | * @cno: checkpoint number |
335 | * @root: nilfs root object |
336 | * @blkinc: number of blocks added by this checkpoint |
337 | * @ctime: checkpoint creation time |
338 | * @minor: minor checkpoint flag |
339 | * |
340 | * This function completes the checkpoint entry numbered by @cno in the |
341 | * cpfile with the data given by the arguments @root, @blkinc, @ctime, and |
342 | * @minor. |
343 | * |
344 | * Return: 0 on success, or the following negative error code on failure. |
345 | * * %-ENOMEM - Insufficient memory available. |
346 | * * %-EIO - I/O error (including metadata corruption). |
347 | */ |
348 | int nilfs_cpfile_finalize_checkpoint(struct inode *cpfile, __u64 cno, |
349 | struct nilfs_root *root, __u64 blkinc, |
350 | time64_t ctime, bool minor) |
351 | { |
352 | struct buffer_head *cp_bh; |
353 | struct nilfs_checkpoint *cp; |
354 | void *kaddr; |
355 | int ret; |
356 | |
357 | if (WARN_ON_ONCE(cno < 1)) |
358 | return -EIO; |
359 | |
360 | down_write(sem: &NILFS_MDT(inode: cpfile)->mi_sem); |
361 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, create: 0, bhp: &cp_bh); |
362 | if (unlikely(ret < 0)) { |
363 | if (ret == -ENOENT) |
364 | goto error; |
365 | goto out_sem; |
366 | } |
367 | |
368 | kaddr = kmap_local_page(page: cp_bh->b_page); |
369 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh: cp_bh, kaddr); |
370 | if (unlikely(nilfs_checkpoint_invalid(cp))) { |
371 | kunmap_local(kaddr); |
372 | brelse(bh: cp_bh); |
373 | goto error; |
374 | } |
375 | |
376 | cp->cp_snapshot_list.ssl_next = 0; |
377 | cp->cp_snapshot_list.ssl_prev = 0; |
378 | cp->cp_inodes_count = cpu_to_le64(atomic64_read(&root->inodes_count)); |
379 | cp->cp_blocks_count = cpu_to_le64(atomic64_read(&root->blocks_count)); |
380 | cp->cp_nblk_inc = cpu_to_le64(blkinc); |
381 | cp->cp_create = cpu_to_le64(ctime); |
382 | cp->cp_cno = cpu_to_le64(cno); |
383 | |
384 | if (minor) |
385 | nilfs_checkpoint_set_minor(cp); |
386 | else |
387 | nilfs_checkpoint_clear_minor(cp); |
388 | |
389 | nilfs_write_inode_common(inode: root->ifile, raw_inode: &cp->cp_ifile_inode); |
390 | nilfs_bmap_write(NILFS_I(inode: root->ifile)->i_bmap, &cp->cp_ifile_inode); |
391 | |
392 | kunmap_local(kaddr); |
393 | brelse(bh: cp_bh); |
394 | out_sem: |
395 | up_write(sem: &NILFS_MDT(inode: cpfile)->mi_sem); |
396 | return ret; |
397 | |
398 | error: |
399 | nilfs_error(cpfile->i_sb, |
400 | "checkpoint finalization failed due to metadata corruption." ); |
401 | ret = -EIO; |
402 | goto out_sem; |
403 | } |
404 | |
405 | /** |
406 | * nilfs_cpfile_delete_checkpoints - delete checkpoints |
407 | * @cpfile: inode of checkpoint file |
408 | * @start: start checkpoint number |
409 | * @end: end checkpoint number |
410 | * |
411 | * Description: nilfs_cpfile_delete_checkpoints() deletes the checkpoints in |
412 | * the period from @start to @end, excluding @end itself. The checkpoints |
413 | * which have been already deleted are ignored. |
414 | * |
415 | * Return Value: On success, 0 is returned. On error, one of the following |
416 | * negative error codes is returned. |
417 | * |
418 | * %-EIO - I/O error. |
419 | * |
420 | * %-ENOMEM - Insufficient amount of memory available. |
421 | * |
422 | * %-EINVAL - invalid checkpoints. |
423 | */ |
424 | int nilfs_cpfile_delete_checkpoints(struct inode *cpfile, |
425 | __u64 start, |
426 | __u64 end) |
427 | { |
428 | struct buffer_head *, *cp_bh; |
429 | struct nilfs_cpfile_header *; |
430 | struct nilfs_checkpoint *cp; |
431 | size_t cpsz = NILFS_MDT(inode: cpfile)->mi_entry_size; |
432 | __u64 cno; |
433 | void *kaddr; |
434 | unsigned long tnicps; |
435 | int ret, ncps, nicps, nss, count, i; |
436 | |
437 | if (unlikely(start == 0 || start > end)) { |
438 | nilfs_err(cpfile->i_sb, |
439 | "cannot delete checkpoints: invalid range [%llu, %llu)" , |
440 | (unsigned long long)start, (unsigned long long)end); |
441 | return -EINVAL; |
442 | } |
443 | |
444 | down_write(sem: &NILFS_MDT(inode: cpfile)->mi_sem); |
445 | |
446 | ret = nilfs_cpfile_get_header_block(cpfile, bhp: &header_bh); |
447 | if (ret < 0) |
448 | goto out_sem; |
449 | tnicps = 0; |
450 | nss = 0; |
451 | |
452 | for (cno = start; cno < end; cno += ncps) { |
453 | ncps = nilfs_cpfile_checkpoints_in_block(cpfile, curr: cno, max: end); |
454 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, create: 0, bhp: &cp_bh); |
455 | if (ret < 0) { |
456 | if (ret != -ENOENT) |
457 | break; |
458 | /* skip hole */ |
459 | ret = 0; |
460 | continue; |
461 | } |
462 | |
463 | kaddr = kmap_local_page(page: cp_bh->b_page); |
464 | cp = nilfs_cpfile_block_get_checkpoint( |
465 | cpfile, cno, bh: cp_bh, kaddr); |
466 | nicps = 0; |
467 | for (i = 0; i < ncps; i++, cp = (void *)cp + cpsz) { |
468 | if (nilfs_checkpoint_snapshot(cp)) { |
469 | nss++; |
470 | } else if (!nilfs_checkpoint_invalid(cp)) { |
471 | nilfs_checkpoint_set_invalid(cp); |
472 | nicps++; |
473 | } |
474 | } |
475 | if (nicps > 0) { |
476 | tnicps += nicps; |
477 | mark_buffer_dirty(bh: cp_bh); |
478 | nilfs_mdt_mark_dirty(inode: cpfile); |
479 | if (!nilfs_cpfile_is_in_first(cpfile, cno)) { |
480 | count = |
481 | nilfs_cpfile_block_sub_valid_checkpoints( |
482 | cpfile, bh: cp_bh, kaddr, n: nicps); |
483 | if (count == 0) { |
484 | /* make hole */ |
485 | kunmap_local(kaddr); |
486 | brelse(bh: cp_bh); |
487 | ret = |
488 | nilfs_cpfile_delete_checkpoint_block( |
489 | cpfile, cno); |
490 | if (ret == 0) |
491 | continue; |
492 | nilfs_err(cpfile->i_sb, |
493 | "error %d deleting checkpoint block" , |
494 | ret); |
495 | break; |
496 | } |
497 | } |
498 | } |
499 | |
500 | kunmap_local(kaddr); |
501 | brelse(bh: cp_bh); |
502 | } |
503 | |
504 | if (tnicps > 0) { |
505 | kaddr = kmap_local_page(page: header_bh->b_page); |
506 | header = nilfs_cpfile_block_get_header(cpfile, bh: header_bh, |
507 | kaddr); |
508 | le64_add_cpu(var: &header->ch_ncheckpoints, val: -(u64)tnicps); |
509 | mark_buffer_dirty(bh: header_bh); |
510 | nilfs_mdt_mark_dirty(inode: cpfile); |
511 | kunmap_local(kaddr); |
512 | } |
513 | |
514 | brelse(bh: header_bh); |
515 | if (nss > 0) |
516 | ret = -EBUSY; |
517 | |
518 | out_sem: |
519 | up_write(sem: &NILFS_MDT(inode: cpfile)->mi_sem); |
520 | return ret; |
521 | } |
522 | |
523 | static void nilfs_cpfile_checkpoint_to_cpinfo(struct inode *cpfile, |
524 | struct nilfs_checkpoint *cp, |
525 | struct nilfs_cpinfo *ci) |
526 | { |
527 | ci->ci_flags = le32_to_cpu(cp->cp_flags); |
528 | ci->ci_cno = le64_to_cpu(cp->cp_cno); |
529 | ci->ci_create = le64_to_cpu(cp->cp_create); |
530 | ci->ci_nblk_inc = le64_to_cpu(cp->cp_nblk_inc); |
531 | ci->ci_inodes_count = le64_to_cpu(cp->cp_inodes_count); |
532 | ci->ci_blocks_count = le64_to_cpu(cp->cp_blocks_count); |
533 | ci->ci_next = le64_to_cpu(cp->cp_snapshot_list.ssl_next); |
534 | } |
535 | |
536 | static ssize_t nilfs_cpfile_do_get_cpinfo(struct inode *cpfile, __u64 *cnop, |
537 | void *buf, unsigned int cisz, |
538 | size_t nci) |
539 | { |
540 | struct nilfs_checkpoint *cp; |
541 | struct nilfs_cpinfo *ci = buf; |
542 | struct buffer_head *bh; |
543 | size_t cpsz = NILFS_MDT(inode: cpfile)->mi_entry_size; |
544 | __u64 cur_cno = nilfs_mdt_cno(inode: cpfile), cno = *cnop; |
545 | void *kaddr; |
546 | int n, ret; |
547 | int ncps, i; |
548 | |
549 | if (cno == 0) |
550 | return -ENOENT; /* checkpoint number 0 is invalid */ |
551 | down_read(sem: &NILFS_MDT(inode: cpfile)->mi_sem); |
552 | |
553 | for (n = 0; n < nci; cno += ncps) { |
554 | ret = nilfs_cpfile_find_checkpoint_block( |
555 | cpfile, start_cno: cno, end_cno: cur_cno - 1, cnop: &cno, bhp: &bh); |
556 | if (ret < 0) { |
557 | if (likely(ret == -ENOENT)) |
558 | break; |
559 | goto out; |
560 | } |
561 | ncps = nilfs_cpfile_checkpoints_in_block(cpfile, curr: cno, max: cur_cno); |
562 | |
563 | kaddr = kmap_local_page(page: bh->b_page); |
564 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr); |
565 | for (i = 0; i < ncps && n < nci; i++, cp = (void *)cp + cpsz) { |
566 | if (!nilfs_checkpoint_invalid(cp)) { |
567 | nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp, |
568 | ci); |
569 | ci = (void *)ci + cisz; |
570 | n++; |
571 | } |
572 | } |
573 | kunmap_local(kaddr); |
574 | brelse(bh); |
575 | } |
576 | |
577 | ret = n; |
578 | if (n > 0) { |
579 | ci = (void *)ci - cisz; |
580 | *cnop = ci->ci_cno + 1; |
581 | } |
582 | |
583 | out: |
584 | up_read(sem: &NILFS_MDT(inode: cpfile)->mi_sem); |
585 | return ret; |
586 | } |
587 | |
588 | static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 *cnop, |
589 | void *buf, unsigned int cisz, |
590 | size_t nci) |
591 | { |
592 | struct buffer_head *bh; |
593 | struct nilfs_cpfile_header *; |
594 | struct nilfs_checkpoint *cp; |
595 | struct nilfs_cpinfo *ci = buf; |
596 | __u64 curr = *cnop, next; |
597 | unsigned long curr_blkoff, next_blkoff; |
598 | void *kaddr; |
599 | int n = 0, ret; |
600 | |
601 | down_read(sem: &NILFS_MDT(inode: cpfile)->mi_sem); |
602 | |
603 | if (curr == 0) { |
604 | ret = nilfs_cpfile_get_header_block(cpfile, bhp: &bh); |
605 | if (ret < 0) |
606 | goto out; |
607 | kaddr = kmap_local_page(page: bh->b_page); |
608 | header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr); |
609 | curr = le64_to_cpu(header->ch_snapshot_list.ssl_next); |
610 | kunmap_local(kaddr); |
611 | brelse(bh); |
612 | if (curr == 0) { |
613 | ret = 0; |
614 | goto out; |
615 | } |
616 | } else if (unlikely(curr == ~(__u64)0)) { |
617 | ret = 0; |
618 | goto out; |
619 | } |
620 | |
621 | curr_blkoff = nilfs_cpfile_get_blkoff(cpfile, cno: curr); |
622 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno: curr, create: 0, bhp: &bh); |
623 | if (unlikely(ret < 0)) { |
624 | if (ret == -ENOENT) |
625 | ret = 0; /* No snapshots (started from a hole block) */ |
626 | goto out; |
627 | } |
628 | kaddr = kmap_local_page(page: bh->b_page); |
629 | while (n < nci) { |
630 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno: curr, bh, kaddr); |
631 | curr = ~(__u64)0; /* Terminator */ |
632 | if (unlikely(nilfs_checkpoint_invalid(cp) || |
633 | !nilfs_checkpoint_snapshot(cp))) |
634 | break; |
635 | nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp, ci); |
636 | ci = (void *)ci + cisz; |
637 | n++; |
638 | next = le64_to_cpu(cp->cp_snapshot_list.ssl_next); |
639 | if (next == 0) |
640 | break; /* reach end of the snapshot list */ |
641 | |
642 | next_blkoff = nilfs_cpfile_get_blkoff(cpfile, cno: next); |
643 | if (curr_blkoff != next_blkoff) { |
644 | kunmap_local(kaddr); |
645 | brelse(bh); |
646 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno: next, |
647 | create: 0, bhp: &bh); |
648 | if (unlikely(ret < 0)) { |
649 | WARN_ON(ret == -ENOENT); |
650 | goto out; |
651 | } |
652 | kaddr = kmap_local_page(page: bh->b_page); |
653 | } |
654 | curr = next; |
655 | curr_blkoff = next_blkoff; |
656 | } |
657 | kunmap_local(kaddr); |
658 | brelse(bh); |
659 | *cnop = curr; |
660 | ret = n; |
661 | |
662 | out: |
663 | up_read(sem: &NILFS_MDT(inode: cpfile)->mi_sem); |
664 | return ret; |
665 | } |
666 | |
667 | /** |
668 | * nilfs_cpfile_get_cpinfo - get information on checkpoints |
669 | * @cpfile: checkpoint file inode |
670 | * @cnop: place to pass a starting checkpoint number and receive a |
671 | * checkpoint number to continue the search |
672 | * @mode: mode of checkpoints that the caller wants to retrieve |
673 | * @buf: buffer for storing checkpoints' information |
674 | * @cisz: byte size of one checkpoint info item in array |
675 | * @nci: number of checkpoint info items to retrieve |
676 | * |
677 | * nilfs_cpfile_get_cpinfo() searches for checkpoints in @mode state |
678 | * starting from the checkpoint number stored in @cnop, and stores |
679 | * information about found checkpoints in @buf. |
680 | * The buffer pointed to by @buf must be large enough to store information |
681 | * for @nci checkpoints. If at least one checkpoint information is |
682 | * successfully retrieved, @cnop is updated to point to the checkpoint |
683 | * number to continue searching. |
684 | * |
685 | * Return: Count of checkpoint info items stored in the output buffer on |
686 | * success, or the following negative error code on failure. |
687 | * * %-EINVAL - Invalid checkpoint mode. |
688 | * * %-ENOMEM - Insufficient memory available. |
689 | * * %-EIO - I/O error (including metadata corruption). |
690 | * * %-ENOENT - Invalid checkpoint number specified. |
691 | */ |
692 | |
693 | ssize_t nilfs_cpfile_get_cpinfo(struct inode *cpfile, __u64 *cnop, int mode, |
694 | void *buf, unsigned int cisz, size_t nci) |
695 | { |
696 | switch (mode) { |
697 | case NILFS_CHECKPOINT: |
698 | return nilfs_cpfile_do_get_cpinfo(cpfile, cnop, buf, cisz, nci); |
699 | case NILFS_SNAPSHOT: |
700 | return nilfs_cpfile_do_get_ssinfo(cpfile, cnop, buf, cisz, nci); |
701 | default: |
702 | return -EINVAL; |
703 | } |
704 | } |
705 | |
706 | /** |
707 | * nilfs_cpfile_delete_checkpoint - |
708 | * @cpfile: |
709 | * @cno: |
710 | */ |
711 | int nilfs_cpfile_delete_checkpoint(struct inode *cpfile, __u64 cno) |
712 | { |
713 | struct nilfs_cpinfo ci; |
714 | __u64 tcno = cno; |
715 | ssize_t nci; |
716 | |
717 | nci = nilfs_cpfile_do_get_cpinfo(cpfile, cnop: &tcno, buf: &ci, cisz: sizeof(ci), nci: 1); |
718 | if (nci < 0) |
719 | return nci; |
720 | else if (nci == 0 || ci.ci_cno != cno) |
721 | return -ENOENT; |
722 | else if (nilfs_cpinfo_snapshot(cpinfo: &ci)) |
723 | return -EBUSY; |
724 | |
725 | return nilfs_cpfile_delete_checkpoints(cpfile, start: cno, end: cno + 1); |
726 | } |
727 | |
728 | static struct nilfs_snapshot_list * |
729 | nilfs_cpfile_block_get_snapshot_list(const struct inode *cpfile, |
730 | __u64 cno, |
731 | struct buffer_head *bh, |
732 | void *kaddr) |
733 | { |
734 | struct nilfs_cpfile_header *; |
735 | struct nilfs_checkpoint *cp; |
736 | struct nilfs_snapshot_list *list; |
737 | |
738 | if (cno != 0) { |
739 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr); |
740 | list = &cp->cp_snapshot_list; |
741 | } else { |
742 | header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr); |
743 | list = &header->ch_snapshot_list; |
744 | } |
745 | return list; |
746 | } |
747 | |
748 | static int nilfs_cpfile_set_snapshot(struct inode *cpfile, __u64 cno) |
749 | { |
750 | struct buffer_head *, *curr_bh, *prev_bh, *cp_bh; |
751 | struct nilfs_cpfile_header *; |
752 | struct nilfs_checkpoint *cp; |
753 | struct nilfs_snapshot_list *list; |
754 | __u64 curr, prev; |
755 | unsigned long curr_blkoff, prev_blkoff; |
756 | void *kaddr; |
757 | int ret; |
758 | |
759 | if (cno == 0) |
760 | return -ENOENT; /* checkpoint number 0 is invalid */ |
761 | down_write(sem: &NILFS_MDT(inode: cpfile)->mi_sem); |
762 | |
763 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, create: 0, bhp: &cp_bh); |
764 | if (ret < 0) |
765 | goto out_sem; |
766 | kaddr = kmap_local_page(page: cp_bh->b_page); |
767 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh: cp_bh, kaddr); |
768 | if (nilfs_checkpoint_invalid(cp)) { |
769 | ret = -ENOENT; |
770 | kunmap_local(kaddr); |
771 | goto out_cp; |
772 | } |
773 | if (nilfs_checkpoint_snapshot(cp)) { |
774 | ret = 0; |
775 | kunmap_local(kaddr); |
776 | goto out_cp; |
777 | } |
778 | kunmap_local(kaddr); |
779 | |
780 | ret = nilfs_cpfile_get_header_block(cpfile, bhp: &header_bh); |
781 | if (ret < 0) |
782 | goto out_cp; |
783 | kaddr = kmap_local_page(page: header_bh->b_page); |
784 | header = nilfs_cpfile_block_get_header(cpfile, bh: header_bh, kaddr); |
785 | list = &header->ch_snapshot_list; |
786 | curr_bh = header_bh; |
787 | get_bh(bh: curr_bh); |
788 | curr = 0; |
789 | curr_blkoff = 0; |
790 | prev = le64_to_cpu(list->ssl_prev); |
791 | while (prev > cno) { |
792 | prev_blkoff = nilfs_cpfile_get_blkoff(cpfile, cno: prev); |
793 | curr = prev; |
794 | if (curr_blkoff != prev_blkoff) { |
795 | kunmap_local(kaddr); |
796 | brelse(bh: curr_bh); |
797 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno: curr, |
798 | create: 0, bhp: &curr_bh); |
799 | if (ret < 0) |
800 | goto out_header; |
801 | kaddr = kmap_local_page(page: curr_bh->b_page); |
802 | } |
803 | curr_blkoff = prev_blkoff; |
804 | cp = nilfs_cpfile_block_get_checkpoint( |
805 | cpfile, cno: curr, bh: curr_bh, kaddr); |
806 | list = &cp->cp_snapshot_list; |
807 | prev = le64_to_cpu(list->ssl_prev); |
808 | } |
809 | kunmap_local(kaddr); |
810 | |
811 | if (prev != 0) { |
812 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno: prev, create: 0, |
813 | bhp: &prev_bh); |
814 | if (ret < 0) |
815 | goto out_curr; |
816 | } else { |
817 | prev_bh = header_bh; |
818 | get_bh(bh: prev_bh); |
819 | } |
820 | |
821 | kaddr = kmap_local_page(page: curr_bh->b_page); |
822 | list = nilfs_cpfile_block_get_snapshot_list( |
823 | cpfile, cno: curr, bh: curr_bh, kaddr); |
824 | list->ssl_prev = cpu_to_le64(cno); |
825 | kunmap_local(kaddr); |
826 | |
827 | kaddr = kmap_local_page(page: cp_bh->b_page); |
828 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh: cp_bh, kaddr); |
829 | cp->cp_snapshot_list.ssl_next = cpu_to_le64(curr); |
830 | cp->cp_snapshot_list.ssl_prev = cpu_to_le64(prev); |
831 | nilfs_checkpoint_set_snapshot(cp); |
832 | kunmap_local(kaddr); |
833 | |
834 | kaddr = kmap_local_page(page: prev_bh->b_page); |
835 | list = nilfs_cpfile_block_get_snapshot_list( |
836 | cpfile, cno: prev, bh: prev_bh, kaddr); |
837 | list->ssl_next = cpu_to_le64(cno); |
838 | kunmap_local(kaddr); |
839 | |
840 | kaddr = kmap_local_page(page: header_bh->b_page); |
841 | header = nilfs_cpfile_block_get_header(cpfile, bh: header_bh, kaddr); |
842 | le64_add_cpu(var: &header->ch_nsnapshots, val: 1); |
843 | kunmap_local(kaddr); |
844 | |
845 | mark_buffer_dirty(bh: prev_bh); |
846 | mark_buffer_dirty(bh: curr_bh); |
847 | mark_buffer_dirty(bh: cp_bh); |
848 | mark_buffer_dirty(bh: header_bh); |
849 | nilfs_mdt_mark_dirty(inode: cpfile); |
850 | |
851 | brelse(bh: prev_bh); |
852 | |
853 | out_curr: |
854 | brelse(bh: curr_bh); |
855 | |
856 | : |
857 | brelse(bh: header_bh); |
858 | |
859 | out_cp: |
860 | brelse(bh: cp_bh); |
861 | |
862 | out_sem: |
863 | up_write(sem: &NILFS_MDT(inode: cpfile)->mi_sem); |
864 | return ret; |
865 | } |
866 | |
867 | static int nilfs_cpfile_clear_snapshot(struct inode *cpfile, __u64 cno) |
868 | { |
869 | struct buffer_head *, *next_bh, *prev_bh, *cp_bh; |
870 | struct nilfs_cpfile_header *; |
871 | struct nilfs_checkpoint *cp; |
872 | struct nilfs_snapshot_list *list; |
873 | __u64 next, prev; |
874 | void *kaddr; |
875 | int ret; |
876 | |
877 | if (cno == 0) |
878 | return -ENOENT; /* checkpoint number 0 is invalid */ |
879 | down_write(sem: &NILFS_MDT(inode: cpfile)->mi_sem); |
880 | |
881 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, create: 0, bhp: &cp_bh); |
882 | if (ret < 0) |
883 | goto out_sem; |
884 | kaddr = kmap_local_page(page: cp_bh->b_page); |
885 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh: cp_bh, kaddr); |
886 | if (nilfs_checkpoint_invalid(cp)) { |
887 | ret = -ENOENT; |
888 | kunmap_local(kaddr); |
889 | goto out_cp; |
890 | } |
891 | if (!nilfs_checkpoint_snapshot(cp)) { |
892 | ret = 0; |
893 | kunmap_local(kaddr); |
894 | goto out_cp; |
895 | } |
896 | |
897 | list = &cp->cp_snapshot_list; |
898 | next = le64_to_cpu(list->ssl_next); |
899 | prev = le64_to_cpu(list->ssl_prev); |
900 | kunmap_local(kaddr); |
901 | |
902 | ret = nilfs_cpfile_get_header_block(cpfile, bhp: &header_bh); |
903 | if (ret < 0) |
904 | goto out_cp; |
905 | if (next != 0) { |
906 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno: next, create: 0, |
907 | bhp: &next_bh); |
908 | if (ret < 0) |
909 | goto out_header; |
910 | } else { |
911 | next_bh = header_bh; |
912 | get_bh(bh: next_bh); |
913 | } |
914 | if (prev != 0) { |
915 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno: prev, create: 0, |
916 | bhp: &prev_bh); |
917 | if (ret < 0) |
918 | goto out_next; |
919 | } else { |
920 | prev_bh = header_bh; |
921 | get_bh(bh: prev_bh); |
922 | } |
923 | |
924 | kaddr = kmap_local_page(page: next_bh->b_page); |
925 | list = nilfs_cpfile_block_get_snapshot_list( |
926 | cpfile, cno: next, bh: next_bh, kaddr); |
927 | list->ssl_prev = cpu_to_le64(prev); |
928 | kunmap_local(kaddr); |
929 | |
930 | kaddr = kmap_local_page(page: prev_bh->b_page); |
931 | list = nilfs_cpfile_block_get_snapshot_list( |
932 | cpfile, cno: prev, bh: prev_bh, kaddr); |
933 | list->ssl_next = cpu_to_le64(next); |
934 | kunmap_local(kaddr); |
935 | |
936 | kaddr = kmap_local_page(page: cp_bh->b_page); |
937 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh: cp_bh, kaddr); |
938 | cp->cp_snapshot_list.ssl_next = cpu_to_le64(0); |
939 | cp->cp_snapshot_list.ssl_prev = cpu_to_le64(0); |
940 | nilfs_checkpoint_clear_snapshot(cp); |
941 | kunmap_local(kaddr); |
942 | |
943 | kaddr = kmap_local_page(page: header_bh->b_page); |
944 | header = nilfs_cpfile_block_get_header(cpfile, bh: header_bh, kaddr); |
945 | le64_add_cpu(var: &header->ch_nsnapshots, val: -1); |
946 | kunmap_local(kaddr); |
947 | |
948 | mark_buffer_dirty(bh: next_bh); |
949 | mark_buffer_dirty(bh: prev_bh); |
950 | mark_buffer_dirty(bh: cp_bh); |
951 | mark_buffer_dirty(bh: header_bh); |
952 | nilfs_mdt_mark_dirty(inode: cpfile); |
953 | |
954 | brelse(bh: prev_bh); |
955 | |
956 | out_next: |
957 | brelse(bh: next_bh); |
958 | |
959 | : |
960 | brelse(bh: header_bh); |
961 | |
962 | out_cp: |
963 | brelse(bh: cp_bh); |
964 | |
965 | out_sem: |
966 | up_write(sem: &NILFS_MDT(inode: cpfile)->mi_sem); |
967 | return ret; |
968 | } |
969 | |
970 | /** |
971 | * nilfs_cpfile_is_snapshot - |
972 | * @cpfile: inode of checkpoint file |
973 | * @cno: checkpoint number |
974 | * |
975 | * Description: |
976 | * |
977 | * Return Value: On success, 1 is returned if the checkpoint specified by |
978 | * @cno is a snapshot, or 0 if not. On error, one of the following negative |
979 | * error codes is returned. |
980 | * |
981 | * %-EIO - I/O error. |
982 | * |
983 | * %-ENOMEM - Insufficient amount of memory available. |
984 | * |
985 | * %-ENOENT - No such checkpoint. |
986 | */ |
987 | int nilfs_cpfile_is_snapshot(struct inode *cpfile, __u64 cno) |
988 | { |
989 | struct buffer_head *bh; |
990 | struct nilfs_checkpoint *cp; |
991 | void *kaddr; |
992 | int ret; |
993 | |
994 | /* |
995 | * CP number is invalid if it's zero or larger than the |
996 | * largest existing one. |
997 | */ |
998 | if (cno == 0 || cno >= nilfs_mdt_cno(inode: cpfile)) |
999 | return -ENOENT; |
1000 | down_read(sem: &NILFS_MDT(inode: cpfile)->mi_sem); |
1001 | |
1002 | ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, create: 0, bhp: &bh); |
1003 | if (ret < 0) |
1004 | goto out; |
1005 | kaddr = kmap_local_page(page: bh->b_page); |
1006 | cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr); |
1007 | if (nilfs_checkpoint_invalid(cp)) |
1008 | ret = -ENOENT; |
1009 | else |
1010 | ret = nilfs_checkpoint_snapshot(cp); |
1011 | kunmap_local(kaddr); |
1012 | brelse(bh); |
1013 | |
1014 | out: |
1015 | up_read(sem: &NILFS_MDT(inode: cpfile)->mi_sem); |
1016 | return ret; |
1017 | } |
1018 | |
1019 | /** |
1020 | * nilfs_cpfile_change_cpmode - change checkpoint mode |
1021 | * @cpfile: inode of checkpoint file |
1022 | * @cno: checkpoint number |
1023 | * @mode: mode of checkpoint |
1024 | * |
1025 | * Description: nilfs_change_cpmode() changes the mode of the checkpoint |
1026 | * specified by @cno. The mode @mode is NILFS_CHECKPOINT or NILFS_SNAPSHOT. |
1027 | * |
1028 | * Return Value: On success, 0 is returned. On error, one of the following |
1029 | * negative error codes is returned. |
1030 | * |
1031 | * %-EIO - I/O error. |
1032 | * |
1033 | * %-ENOMEM - Insufficient amount of memory available. |
1034 | * |
1035 | * %-ENOENT - No such checkpoint. |
1036 | */ |
1037 | int nilfs_cpfile_change_cpmode(struct inode *cpfile, __u64 cno, int mode) |
1038 | { |
1039 | int ret; |
1040 | |
1041 | switch (mode) { |
1042 | case NILFS_CHECKPOINT: |
1043 | if (nilfs_checkpoint_is_mounted(sb: cpfile->i_sb, cno)) |
1044 | /* |
1045 | * Current implementation does not have to protect |
1046 | * plain read-only mounts since they are exclusive |
1047 | * with a read/write mount and are protected from the |
1048 | * cleaner. |
1049 | */ |
1050 | ret = -EBUSY; |
1051 | else |
1052 | ret = nilfs_cpfile_clear_snapshot(cpfile, cno); |
1053 | return ret; |
1054 | case NILFS_SNAPSHOT: |
1055 | return nilfs_cpfile_set_snapshot(cpfile, cno); |
1056 | default: |
1057 | return -EINVAL; |
1058 | } |
1059 | } |
1060 | |
1061 | /** |
1062 | * nilfs_cpfile_get_stat - get checkpoint statistics |
1063 | * @cpfile: inode of checkpoint file |
1064 | * @cpstat: pointer to a structure of checkpoint statistics |
1065 | * |
1066 | * Description: nilfs_cpfile_get_stat() returns information about checkpoints. |
1067 | * |
1068 | * Return Value: On success, 0 is returned, and checkpoints information is |
1069 | * stored in the place pointed by @cpstat. On error, one of the following |
1070 | * negative error codes is returned. |
1071 | * |
1072 | * %-EIO - I/O error. |
1073 | * |
1074 | * %-ENOMEM - Insufficient amount of memory available. |
1075 | */ |
1076 | int nilfs_cpfile_get_stat(struct inode *cpfile, struct nilfs_cpstat *cpstat) |
1077 | { |
1078 | struct buffer_head *bh; |
1079 | struct nilfs_cpfile_header *; |
1080 | void *kaddr; |
1081 | int ret; |
1082 | |
1083 | down_read(sem: &NILFS_MDT(inode: cpfile)->mi_sem); |
1084 | |
1085 | ret = nilfs_cpfile_get_header_block(cpfile, bhp: &bh); |
1086 | if (ret < 0) |
1087 | goto out_sem; |
1088 | kaddr = kmap_local_page(page: bh->b_page); |
1089 | header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr); |
1090 | cpstat->cs_cno = nilfs_mdt_cno(inode: cpfile); |
1091 | cpstat->cs_ncps = le64_to_cpu(header->ch_ncheckpoints); |
1092 | cpstat->cs_nsss = le64_to_cpu(header->ch_nsnapshots); |
1093 | kunmap_local(kaddr); |
1094 | brelse(bh); |
1095 | |
1096 | out_sem: |
1097 | up_read(sem: &NILFS_MDT(inode: cpfile)->mi_sem); |
1098 | return ret; |
1099 | } |
1100 | |
1101 | /** |
1102 | * nilfs_cpfile_read - read or get cpfile inode |
1103 | * @sb: super block instance |
1104 | * @cpsize: size of a checkpoint entry |
1105 | * @raw_inode: on-disk cpfile inode |
1106 | * @inodep: buffer to store the inode |
1107 | */ |
1108 | int nilfs_cpfile_read(struct super_block *sb, size_t cpsize, |
1109 | struct nilfs_inode *raw_inode, struct inode **inodep) |
1110 | { |
1111 | struct inode *cpfile; |
1112 | int err; |
1113 | |
1114 | if (cpsize > sb->s_blocksize) { |
1115 | nilfs_err(sb, "too large checkpoint size: %zu bytes" , cpsize); |
1116 | return -EINVAL; |
1117 | } else if (cpsize < NILFS_MIN_CHECKPOINT_SIZE) { |
1118 | nilfs_err(sb, "too small checkpoint size: %zu bytes" , cpsize); |
1119 | return -EINVAL; |
1120 | } |
1121 | |
1122 | cpfile = nilfs_iget_locked(sb, NULL, NILFS_CPFILE_INO); |
1123 | if (unlikely(!cpfile)) |
1124 | return -ENOMEM; |
1125 | if (!(cpfile->i_state & I_NEW)) |
1126 | goto out; |
1127 | |
1128 | err = nilfs_mdt_init(inode: cpfile, NILFS_MDT_GFP, objsz: 0); |
1129 | if (err) |
1130 | goto failed; |
1131 | |
1132 | nilfs_mdt_set_entry_size(cpfile, cpsize, |
1133 | sizeof(struct nilfs_cpfile_header)); |
1134 | |
1135 | err = nilfs_read_inode_common(cpfile, raw_inode); |
1136 | if (err) |
1137 | goto failed; |
1138 | |
1139 | unlock_new_inode(cpfile); |
1140 | out: |
1141 | *inodep = cpfile; |
1142 | return 0; |
1143 | failed: |
1144 | iget_failed(cpfile); |
1145 | return err; |
1146 | } |
1147 | |