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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 * Written by Koji Sato.
17 */
18
19#include <linux/kernel.h>
20#include <linux/fs.h>
21#include <linux/string.h>
22#include <linux/buffer_head.h>
23#include <linux/errno.h>
24#include "mdt.h"
25#include "cpfile.h"
26
27
28static inline unsigned long
29nilfs_cpfile_checkpoints_per_block(const struct inode *cpfile)
30{
31 return NILFS_MDT(cpfile)->mi_entries_per_block;
32}
33
34/* block number from the beginning of the file */
35static unsigned long
36nilfs_cpfile_get_blkoff(const struct inode *cpfile, __u64 cno)
37{
38 __u64 tcno = cno + NILFS_MDT(cpfile)->mi_first_entry_offset - 1;
39
40 do_div(tcno, nilfs_cpfile_checkpoints_per_block(cpfile));
41 return (unsigned long)tcno;
42}
43
44/* offset in block */
45static unsigned long
46nilfs_cpfile_get_offset(const struct inode *cpfile, __u64 cno)
47{
48 __u64 tcno = cno + NILFS_MDT(cpfile)->mi_first_entry_offset - 1;
49
50 return do_div(tcno, nilfs_cpfile_checkpoints_per_block(cpfile));
51}
52
53static __u64 nilfs_cpfile_first_checkpoint_in_block(const struct inode *cpfile,
54 unsigned long blkoff)
55{
56 return (__u64)nilfs_cpfile_checkpoints_per_block(cpfile) * blkoff
57 + 1 - NILFS_MDT(cpfile)->mi_first_entry_offset;
58}
59
60static unsigned long
61nilfs_cpfile_checkpoints_in_block(const struct inode *cpfile,
62 __u64 curr,
63 __u64 max)
64{
65 return min_t(__u64,
66 nilfs_cpfile_checkpoints_per_block(cpfile) -
67 nilfs_cpfile_get_offset(cpfile, curr),
68 max - curr);
69}
70
71static inline int nilfs_cpfile_is_in_first(const struct inode *cpfile,
72 __u64 cno)
73{
74 return nilfs_cpfile_get_blkoff(cpfile, cno) == 0;
75}
76
77static unsigned int
78nilfs_cpfile_block_add_valid_checkpoints(const struct inode *cpfile,
79 struct buffer_head *bh,
80 void *kaddr,
81 unsigned int n)
82{
83 struct nilfs_checkpoint *cp = kaddr + bh_offset(bh);
84 unsigned int count;
85
86 count = le32_to_cpu(cp->cp_checkpoints_count) + n;
87 cp->cp_checkpoints_count = cpu_to_le32(count);
88 return count;
89}
90
91static unsigned int
92nilfs_cpfile_block_sub_valid_checkpoints(const struct inode *cpfile,
93 struct buffer_head *bh,
94 void *kaddr,
95 unsigned int n)
96{
97 struct nilfs_checkpoint *cp = kaddr + bh_offset(bh);
98 unsigned int count;
99
100 WARN_ON(le32_to_cpu(cp->cp_checkpoints_count) < n);
101 count = le32_to_cpu(cp->cp_checkpoints_count) - n;
102 cp->cp_checkpoints_count = cpu_to_le32(count);
103 return count;
104}
105
106static inline struct nilfs_cpfile_header *
107nilfs_cpfile_block_get_header(const struct inode *cpfile,
108 struct buffer_head *bh,
109 void *kaddr)
110{
111 return kaddr + bh_offset(bh);
112}
113
114static struct nilfs_checkpoint *
115nilfs_cpfile_block_get_checkpoint(const struct inode *cpfile, __u64 cno,
116 struct buffer_head *bh,
117 void *kaddr)
118{
119 return kaddr + bh_offset(bh) + nilfs_cpfile_get_offset(cpfile, cno) *
120 NILFS_MDT(cpfile)->mi_entry_size;
121}
122
123static void nilfs_cpfile_block_init(struct inode *cpfile,
124 struct buffer_head *bh,
125 void *kaddr)
126{
127 struct nilfs_checkpoint *cp = kaddr + bh_offset(bh);
128 size_t cpsz = NILFS_MDT(cpfile)->mi_entry_size;
129 int n = nilfs_cpfile_checkpoints_per_block(cpfile);
130
131 while (n-- > 0) {
132 nilfs_checkpoint_set_invalid(cp);
133 cp = (void *)cp + cpsz;
134 }
135}
136
137static inline int nilfs_cpfile_get_header_block(struct inode *cpfile,
138 struct buffer_head **bhp)
139{
140 return nilfs_mdt_get_block(cpfile, 0, 0, NULL, bhp);
141}
142
143static inline int nilfs_cpfile_get_checkpoint_block(struct inode *cpfile,
144 __u64 cno,
145 int create,
146 struct buffer_head **bhp)
147{
148 return nilfs_mdt_get_block(cpfile,
149 nilfs_cpfile_get_blkoff(cpfile, cno),
150 create, nilfs_cpfile_block_init, bhp);
151}
152
153/**
154 * nilfs_cpfile_find_checkpoint_block - find and get a buffer on cpfile
155 * @cpfile: inode of cpfile
156 * @start_cno: start checkpoint number (inclusive)
157 * @end_cno: end checkpoint number (inclusive)
158 * @cnop: place to store the next checkpoint number
159 * @bhp: place to store a pointer to buffer_head struct
160 *
161 * Return Value: On success, it returns 0. On error, the following negative
162 * error code is returned.
163 *
164 * %-ENOMEM - Insufficient memory available.
165 *
166 * %-EIO - I/O error
167 *
168 * %-ENOENT - no block exists in the range.
169 */
170static int nilfs_cpfile_find_checkpoint_block(struct inode *cpfile,
171 __u64 start_cno, __u64 end_cno,
172 __u64 *cnop,
173 struct buffer_head **bhp)
174{
175 unsigned long start, end, blkoff;
176 int ret;
177
178 if (unlikely(start_cno > end_cno))
179 return -ENOENT;
180
181 start = nilfs_cpfile_get_blkoff(cpfile, start_cno);
182 end = nilfs_cpfile_get_blkoff(cpfile, end_cno);
183
184 ret = nilfs_mdt_find_block(cpfile, start, end, &blkoff, bhp);
185 if (!ret)
186 *cnop = (blkoff == start) ? start_cno :
187 nilfs_cpfile_first_checkpoint_in_block(cpfile, blkoff);
188 return ret;
189}
190
191static inline int nilfs_cpfile_delete_checkpoint_block(struct inode *cpfile,
192 __u64 cno)
193{
194 return nilfs_mdt_delete_block(cpfile,
195 nilfs_cpfile_get_blkoff(cpfile, cno));
196}
197
198/**
199 * nilfs_cpfile_get_checkpoint - get a checkpoint
200 * @cpfile: inode of checkpoint file
201 * @cno: checkpoint number
202 * @create: create flag
203 * @cpp: pointer to a checkpoint
204 * @bhp: pointer to a buffer head
205 *
206 * Description: nilfs_cpfile_get_checkpoint() acquires the checkpoint
207 * specified by @cno. A new checkpoint will be created if @cno is the current
208 * checkpoint number and @create is nonzero.
209 *
210 * Return Value: On success, 0 is returned, and the checkpoint and the
211 * buffer head of the buffer on which the checkpoint is located are stored in
212 * the place pointed by @cpp and @bhp, respectively. On error, one of the
213 * following negative error codes is returned.
214 *
215 * %-EIO - I/O error.
216 *
217 * %-ENOMEM - Insufficient amount of memory available.
218 *
219 * %-ENOENT - No such checkpoint.
220 *
221 * %-EINVAL - invalid checkpoint.
222 */
223int nilfs_cpfile_get_checkpoint(struct inode *cpfile,
224 __u64 cno,
225 int create,
226 struct nilfs_checkpoint **cpp,
227 struct buffer_head **bhp)
228{
229 struct buffer_head *header_bh, *cp_bh;
230 struct nilfs_cpfile_header *header;
231 struct nilfs_checkpoint *cp;
232 void *kaddr;
233 int ret;
234
235 if (unlikely(cno < 1 || cno > nilfs_mdt_cno(cpfile) ||
236 (cno < nilfs_mdt_cno(cpfile) && create)))
237 return -EINVAL;
238
239 down_write(&NILFS_MDT(cpfile)->mi_sem);
240
241 ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
242 if (ret < 0)
243 goto out_sem;
244 ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, create, &cp_bh);
245 if (ret < 0)
246 goto out_header;
247 kaddr = kmap(cp_bh->b_page);
248 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
249 if (nilfs_checkpoint_invalid(cp)) {
250 if (!create) {
251 kunmap(cp_bh->b_page);
252 brelse(cp_bh);
253 ret = -ENOENT;
254 goto out_header;
255 }
256 /* a newly-created checkpoint */
257 nilfs_checkpoint_clear_invalid(cp);
258 if (!nilfs_cpfile_is_in_first(cpfile, cno))
259 nilfs_cpfile_block_add_valid_checkpoints(cpfile, cp_bh,
260 kaddr, 1);
261 mark_buffer_dirty(cp_bh);
262
263 kaddr = kmap_atomic(header_bh->b_page);
264 header = nilfs_cpfile_block_get_header(cpfile, header_bh,
265 kaddr);
266 le64_add_cpu(&header->ch_ncheckpoints, 1);
267 kunmap_atomic(kaddr);
268 mark_buffer_dirty(header_bh);
269 nilfs_mdt_mark_dirty(cpfile);
270 }
271
272 if (cpp != NULL)
273 *cpp = cp;
274 *bhp = cp_bh;
275
276 out_header:
277 brelse(header_bh);
278
279 out_sem:
280 up_write(&NILFS_MDT(cpfile)->mi_sem);
281 return ret;
282}
283
284/**
285 * nilfs_cpfile_put_checkpoint - put a checkpoint
286 * @cpfile: inode of checkpoint file
287 * @cno: checkpoint number
288 * @bh: buffer head
289 *
290 * Description: nilfs_cpfile_put_checkpoint() releases the checkpoint
291 * specified by @cno. @bh must be the buffer head which has been returned by
292 * a previous call to nilfs_cpfile_get_checkpoint() with @cno.
293 */
294void nilfs_cpfile_put_checkpoint(struct inode *cpfile, __u64 cno,
295 struct buffer_head *bh)
296{
297 kunmap(bh->b_page);
298 brelse(bh);
299}
300
301/**
302 * nilfs_cpfile_delete_checkpoints - delete checkpoints
303 * @cpfile: inode of checkpoint file
304 * @start: start checkpoint number
305 * @end: end checkpoint numer
306 *
307 * Description: nilfs_cpfile_delete_checkpoints() deletes the checkpoints in
308 * the period from @start to @end, excluding @end itself. The checkpoints
309 * which have been already deleted are ignored.
310 *
311 * Return Value: On success, 0 is returned. On error, one of the following
312 * negative error codes is returned.
313 *
314 * %-EIO - I/O error.
315 *
316 * %-ENOMEM - Insufficient amount of memory available.
317 *
318 * %-EINVAL - invalid checkpoints.
319 */
320int nilfs_cpfile_delete_checkpoints(struct inode *cpfile,
321 __u64 start,
322 __u64 end)
323{
324 struct buffer_head *header_bh, *cp_bh;
325 struct nilfs_cpfile_header *header;
326 struct nilfs_checkpoint *cp;
327 size_t cpsz = NILFS_MDT(cpfile)->mi_entry_size;
328 __u64 cno;
329 void *kaddr;
330 unsigned long tnicps;
331 int ret, ncps, nicps, nss, count, i;
332
333 if (unlikely(start == 0 || start > end)) {
334 nilfs_msg(cpfile->i_sb, KERN_ERR,
335 "cannot delete checkpoints: invalid range [%llu, %llu)",
336 (unsigned long long)start, (unsigned long long)end);
337 return -EINVAL;
338 }
339
340 down_write(&NILFS_MDT(cpfile)->mi_sem);
341
342 ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
343 if (ret < 0)
344 goto out_sem;
345 tnicps = 0;
346 nss = 0;
347
348 for (cno = start; cno < end; cno += ncps) {
349 ncps = nilfs_cpfile_checkpoints_in_block(cpfile, cno, end);
350 ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh);
351 if (ret < 0) {
352 if (ret != -ENOENT)
353 break;
354 /* skip hole */
355 ret = 0;
356 continue;
357 }
358
359 kaddr = kmap_atomic(cp_bh->b_page);
360 cp = nilfs_cpfile_block_get_checkpoint(
361 cpfile, cno, cp_bh, kaddr);
362 nicps = 0;
363 for (i = 0; i < ncps; i++, cp = (void *)cp + cpsz) {
364 if (nilfs_checkpoint_snapshot(cp)) {
365 nss++;
366 } else if (!nilfs_checkpoint_invalid(cp)) {
367 nilfs_checkpoint_set_invalid(cp);
368 nicps++;
369 }
370 }
371 if (nicps > 0) {
372 tnicps += nicps;
373 mark_buffer_dirty(cp_bh);
374 nilfs_mdt_mark_dirty(cpfile);
375 if (!nilfs_cpfile_is_in_first(cpfile, cno)) {
376 count =
377 nilfs_cpfile_block_sub_valid_checkpoints(
378 cpfile, cp_bh, kaddr, nicps);
379 if (count == 0) {
380 /* make hole */
381 kunmap_atomic(kaddr);
382 brelse(cp_bh);
383 ret =
384 nilfs_cpfile_delete_checkpoint_block(
385 cpfile, cno);
386 if (ret == 0)
387 continue;
388 nilfs_msg(cpfile->i_sb, KERN_ERR,
389 "error %d deleting checkpoint block",
390 ret);
391 break;
392 }
393 }
394 }
395
396 kunmap_atomic(kaddr);
397 brelse(cp_bh);
398 }
399
400 if (tnicps > 0) {
401 kaddr = kmap_atomic(header_bh->b_page);
402 header = nilfs_cpfile_block_get_header(cpfile, header_bh,
403 kaddr);
404 le64_add_cpu(&header->ch_ncheckpoints, -(u64)tnicps);
405 mark_buffer_dirty(header_bh);
406 nilfs_mdt_mark_dirty(cpfile);
407 kunmap_atomic(kaddr);
408 }
409
410 brelse(header_bh);
411 if (nss > 0)
412 ret = -EBUSY;
413
414 out_sem:
415 up_write(&NILFS_MDT(cpfile)->mi_sem);
416 return ret;
417}
418
419static void nilfs_cpfile_checkpoint_to_cpinfo(struct inode *cpfile,
420 struct nilfs_checkpoint *cp,
421 struct nilfs_cpinfo *ci)
422{
423 ci->ci_flags = le32_to_cpu(cp->cp_flags);
424 ci->ci_cno = le64_to_cpu(cp->cp_cno);
425 ci->ci_create = le64_to_cpu(cp->cp_create);
426 ci->ci_nblk_inc = le64_to_cpu(cp->cp_nblk_inc);
427 ci->ci_inodes_count = le64_to_cpu(cp->cp_inodes_count);
428 ci->ci_blocks_count = le64_to_cpu(cp->cp_blocks_count);
429 ci->ci_next = le64_to_cpu(cp->cp_snapshot_list.ssl_next);
430}
431
432static ssize_t nilfs_cpfile_do_get_cpinfo(struct inode *cpfile, __u64 *cnop,
433 void *buf, unsigned int cisz,
434 size_t nci)
435{
436 struct nilfs_checkpoint *cp;
437 struct nilfs_cpinfo *ci = buf;
438 struct buffer_head *bh;
439 size_t cpsz = NILFS_MDT(cpfile)->mi_entry_size;
440 __u64 cur_cno = nilfs_mdt_cno(cpfile), cno = *cnop;
441 void *kaddr;
442 int n, ret;
443 int ncps, i;
444
445 if (cno == 0)
446 return -ENOENT; /* checkpoint number 0 is invalid */
447 down_read(&NILFS_MDT(cpfile)->mi_sem);
448
449 for (n = 0; n < nci; cno += ncps) {
450 ret = nilfs_cpfile_find_checkpoint_block(
451 cpfile, cno, cur_cno - 1, &cno, &bh);
452 if (ret < 0) {
453 if (likely(ret == -ENOENT))
454 break;
455 goto out;
456 }
457 ncps = nilfs_cpfile_checkpoints_in_block(cpfile, cno, cur_cno);
458
459 kaddr = kmap_atomic(bh->b_page);
460 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr);
461 for (i = 0; i < ncps && n < nci; i++, cp = (void *)cp + cpsz) {
462 if (!nilfs_checkpoint_invalid(cp)) {
463 nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp,
464 ci);
465 ci = (void *)ci + cisz;
466 n++;
467 }
468 }
469 kunmap_atomic(kaddr);
470 brelse(bh);
471 }
472
473 ret = n;
474 if (n > 0) {
475 ci = (void *)ci - cisz;
476 *cnop = ci->ci_cno + 1;
477 }
478
479 out:
480 up_read(&NILFS_MDT(cpfile)->mi_sem);
481 return ret;
482}
483
484static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 *cnop,
485 void *buf, unsigned int cisz,
486 size_t nci)
487{
488 struct buffer_head *bh;
489 struct nilfs_cpfile_header *header;
490 struct nilfs_checkpoint *cp;
491 struct nilfs_cpinfo *ci = buf;
492 __u64 curr = *cnop, next;
493 unsigned long curr_blkoff, next_blkoff;
494 void *kaddr;
495 int n = 0, ret;
496
497 down_read(&NILFS_MDT(cpfile)->mi_sem);
498
499 if (curr == 0) {
500 ret = nilfs_cpfile_get_header_block(cpfile, &bh);
501 if (ret < 0)
502 goto out;
503 kaddr = kmap_atomic(bh->b_page);
504 header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr);
505 curr = le64_to_cpu(header->ch_snapshot_list.ssl_next);
506 kunmap_atomic(kaddr);
507 brelse(bh);
508 if (curr == 0) {
509 ret = 0;
510 goto out;
511 }
512 } else if (unlikely(curr == ~(__u64)0)) {
513 ret = 0;
514 goto out;
515 }
516
517 curr_blkoff = nilfs_cpfile_get_blkoff(cpfile, curr);
518 ret = nilfs_cpfile_get_checkpoint_block(cpfile, curr, 0, &bh);
519 if (unlikely(ret < 0)) {
520 if (ret == -ENOENT)
521 ret = 0; /* No snapshots (started from a hole block) */
522 goto out;
523 }
524 kaddr = kmap_atomic(bh->b_page);
525 while (n < nci) {
526 cp = nilfs_cpfile_block_get_checkpoint(cpfile, curr, bh, kaddr);
527 curr = ~(__u64)0; /* Terminator */
528 if (unlikely(nilfs_checkpoint_invalid(cp) ||
529 !nilfs_checkpoint_snapshot(cp)))
530 break;
531 nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp, ci);
532 ci = (void *)ci + cisz;
533 n++;
534 next = le64_to_cpu(cp->cp_snapshot_list.ssl_next);
535 if (next == 0)
536 break; /* reach end of the snapshot list */
537
538 next_blkoff = nilfs_cpfile_get_blkoff(cpfile, next);
539 if (curr_blkoff != next_blkoff) {
540 kunmap_atomic(kaddr);
541 brelse(bh);
542 ret = nilfs_cpfile_get_checkpoint_block(cpfile, next,
543 0, &bh);
544 if (unlikely(ret < 0)) {
545 WARN_ON(ret == -ENOENT);
546 goto out;
547 }
548 kaddr = kmap_atomic(bh->b_page);
549 }
550 curr = next;
551 curr_blkoff = next_blkoff;
552 }
553 kunmap_atomic(kaddr);
554 brelse(bh);
555 *cnop = curr;
556 ret = n;
557
558 out:
559 up_read(&NILFS_MDT(cpfile)->mi_sem);
560 return ret;
561}
562
563/**
564 * nilfs_cpfile_get_cpinfo -
565 * @cpfile:
566 * @cno:
567 * @ci:
568 * @nci:
569 */
570
571ssize_t nilfs_cpfile_get_cpinfo(struct inode *cpfile, __u64 *cnop, int mode,
572 void *buf, unsigned int cisz, size_t nci)
573{
574 switch (mode) {
575 case NILFS_CHECKPOINT:
576 return nilfs_cpfile_do_get_cpinfo(cpfile, cnop, buf, cisz, nci);
577 case NILFS_SNAPSHOT:
578 return nilfs_cpfile_do_get_ssinfo(cpfile, cnop, buf, cisz, nci);
579 default:
580 return -EINVAL;
581 }
582}
583
584/**
585 * nilfs_cpfile_delete_checkpoint -
586 * @cpfile:
587 * @cno:
588 */
589int nilfs_cpfile_delete_checkpoint(struct inode *cpfile, __u64 cno)
590{
591 struct nilfs_cpinfo ci;
592 __u64 tcno = cno;
593 ssize_t nci;
594
595 nci = nilfs_cpfile_do_get_cpinfo(cpfile, &tcno, &ci, sizeof(ci), 1);
596 if (nci < 0)
597 return nci;
598 else if (nci == 0 || ci.ci_cno != cno)
599 return -ENOENT;
600 else if (nilfs_cpinfo_snapshot(&ci))
601 return -EBUSY;
602
603 return nilfs_cpfile_delete_checkpoints(cpfile, cno, cno + 1);
604}
605
606static struct nilfs_snapshot_list *
607nilfs_cpfile_block_get_snapshot_list(const struct inode *cpfile,
608 __u64 cno,
609 struct buffer_head *bh,
610 void *kaddr)
611{
612 struct nilfs_cpfile_header *header;
613 struct nilfs_checkpoint *cp;
614 struct nilfs_snapshot_list *list;
615
616 if (cno != 0) {
617 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr);
618 list = &cp->cp_snapshot_list;
619 } else {
620 header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr);
621 list = &header->ch_snapshot_list;
622 }
623 return list;
624}
625
626static int nilfs_cpfile_set_snapshot(struct inode *cpfile, __u64 cno)
627{
628 struct buffer_head *header_bh, *curr_bh, *prev_bh, *cp_bh;
629 struct nilfs_cpfile_header *header;
630 struct nilfs_checkpoint *cp;
631 struct nilfs_snapshot_list *list;
632 __u64 curr, prev;
633 unsigned long curr_blkoff, prev_blkoff;
634 void *kaddr;
635 int ret;
636
637 if (cno == 0)
638 return -ENOENT; /* checkpoint number 0 is invalid */
639 down_write(&NILFS_MDT(cpfile)->mi_sem);
640
641 ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh);
642 if (ret < 0)
643 goto out_sem;
644 kaddr = kmap_atomic(cp_bh->b_page);
645 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
646 if (nilfs_checkpoint_invalid(cp)) {
647 ret = -ENOENT;
648 kunmap_atomic(kaddr);
649 goto out_cp;
650 }
651 if (nilfs_checkpoint_snapshot(cp)) {
652 ret = 0;
653 kunmap_atomic(kaddr);
654 goto out_cp;
655 }
656 kunmap_atomic(kaddr);
657
658 ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
659 if (ret < 0)
660 goto out_cp;
661 kaddr = kmap_atomic(header_bh->b_page);
662 header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr);
663 list = &header->ch_snapshot_list;
664 curr_bh = header_bh;
665 get_bh(curr_bh);
666 curr = 0;
667 curr_blkoff = 0;
668 prev = le64_to_cpu(list->ssl_prev);
669 while (prev > cno) {
670 prev_blkoff = nilfs_cpfile_get_blkoff(cpfile, prev);
671 curr = prev;
672 if (curr_blkoff != prev_blkoff) {
673 kunmap_atomic(kaddr);
674 brelse(curr_bh);
675 ret = nilfs_cpfile_get_checkpoint_block(cpfile, curr,
676 0, &curr_bh);
677 if (ret < 0)
678 goto out_header;
679 kaddr = kmap_atomic(curr_bh->b_page);
680 }
681 curr_blkoff = prev_blkoff;
682 cp = nilfs_cpfile_block_get_checkpoint(
683 cpfile, curr, curr_bh, kaddr);
684 list = &cp->cp_snapshot_list;
685 prev = le64_to_cpu(list->ssl_prev);
686 }
687 kunmap_atomic(kaddr);
688
689 if (prev != 0) {
690 ret = nilfs_cpfile_get_checkpoint_block(cpfile, prev, 0,
691 &prev_bh);
692 if (ret < 0)
693 goto out_curr;
694 } else {
695 prev_bh = header_bh;
696 get_bh(prev_bh);
697 }
698
699 kaddr = kmap_atomic(curr_bh->b_page);
700 list = nilfs_cpfile_block_get_snapshot_list(
701 cpfile, curr, curr_bh, kaddr);
702 list->ssl_prev = cpu_to_le64(cno);
703 kunmap_atomic(kaddr);
704
705 kaddr = kmap_atomic(cp_bh->b_page);
706 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
707 cp->cp_snapshot_list.ssl_next = cpu_to_le64(curr);
708 cp->cp_snapshot_list.ssl_prev = cpu_to_le64(prev);
709 nilfs_checkpoint_set_snapshot(cp);
710 kunmap_atomic(kaddr);
711
712 kaddr = kmap_atomic(prev_bh->b_page);
713 list = nilfs_cpfile_block_get_snapshot_list(
714 cpfile, prev, prev_bh, kaddr);
715 list->ssl_next = cpu_to_le64(cno);
716 kunmap_atomic(kaddr);
717
718 kaddr = kmap_atomic(header_bh->b_page);
719 header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr);
720 le64_add_cpu(&header->ch_nsnapshots, 1);
721 kunmap_atomic(kaddr);
722
723 mark_buffer_dirty(prev_bh);
724 mark_buffer_dirty(curr_bh);
725 mark_buffer_dirty(cp_bh);
726 mark_buffer_dirty(header_bh);
727 nilfs_mdt_mark_dirty(cpfile);
728
729 brelse(prev_bh);
730
731 out_curr:
732 brelse(curr_bh);
733
734 out_header:
735 brelse(header_bh);
736
737 out_cp:
738 brelse(cp_bh);
739
740 out_sem:
741 up_write(&NILFS_MDT(cpfile)->mi_sem);
742 return ret;
743}
744
745static int nilfs_cpfile_clear_snapshot(struct inode *cpfile, __u64 cno)
746{
747 struct buffer_head *header_bh, *next_bh, *prev_bh, *cp_bh;
748 struct nilfs_cpfile_header *header;
749 struct nilfs_checkpoint *cp;
750 struct nilfs_snapshot_list *list;
751 __u64 next, prev;
752 void *kaddr;
753 int ret;
754
755 if (cno == 0)
756 return -ENOENT; /* checkpoint number 0 is invalid */
757 down_write(&NILFS_MDT(cpfile)->mi_sem);
758
759 ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh);
760 if (ret < 0)
761 goto out_sem;
762 kaddr = kmap_atomic(cp_bh->b_page);
763 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
764 if (nilfs_checkpoint_invalid(cp)) {
765 ret = -ENOENT;
766 kunmap_atomic(kaddr);
767 goto out_cp;
768 }
769 if (!nilfs_checkpoint_snapshot(cp)) {
770 ret = 0;
771 kunmap_atomic(kaddr);
772 goto out_cp;
773 }
774
775 list = &cp->cp_snapshot_list;
776 next = le64_to_cpu(list->ssl_next);
777 prev = le64_to_cpu(list->ssl_prev);
778 kunmap_atomic(kaddr);
779
780 ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
781 if (ret < 0)
782 goto out_cp;
783 if (next != 0) {
784 ret = nilfs_cpfile_get_checkpoint_block(cpfile, next, 0,
785 &next_bh);
786 if (ret < 0)
787 goto out_header;
788 } else {
789 next_bh = header_bh;
790 get_bh(next_bh);
791 }
792 if (prev != 0) {
793 ret = nilfs_cpfile_get_checkpoint_block(cpfile, prev, 0,
794 &prev_bh);
795 if (ret < 0)
796 goto out_next;
797 } else {
798 prev_bh = header_bh;
799 get_bh(prev_bh);
800 }
801
802 kaddr = kmap_atomic(next_bh->b_page);
803 list = nilfs_cpfile_block_get_snapshot_list(
804 cpfile, next, next_bh, kaddr);
805 list->ssl_prev = cpu_to_le64(prev);
806 kunmap_atomic(kaddr);
807
808 kaddr = kmap_atomic(prev_bh->b_page);
809 list = nilfs_cpfile_block_get_snapshot_list(
810 cpfile, prev, prev_bh, kaddr);
811 list->ssl_next = cpu_to_le64(next);
812 kunmap_atomic(kaddr);
813
814 kaddr = kmap_atomic(cp_bh->b_page);
815 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
816 cp->cp_snapshot_list.ssl_next = cpu_to_le64(0);
817 cp->cp_snapshot_list.ssl_prev = cpu_to_le64(0);
818 nilfs_checkpoint_clear_snapshot(cp);
819 kunmap_atomic(kaddr);
820
821 kaddr = kmap_atomic(header_bh->b_page);
822 header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr);
823 le64_add_cpu(&header->ch_nsnapshots, -1);
824 kunmap_atomic(kaddr);
825
826 mark_buffer_dirty(next_bh);
827 mark_buffer_dirty(prev_bh);
828 mark_buffer_dirty(cp_bh);
829 mark_buffer_dirty(header_bh);
830 nilfs_mdt_mark_dirty(cpfile);
831
832 brelse(prev_bh);
833
834 out_next:
835 brelse(next_bh);
836
837 out_header:
838 brelse(header_bh);
839
840 out_cp:
841 brelse(cp_bh);
842
843 out_sem:
844 up_write(&NILFS_MDT(cpfile)->mi_sem);
845 return ret;
846}
847
848/**
849 * nilfs_cpfile_is_snapshot -
850 * @cpfile: inode of checkpoint file
851 * @cno: checkpoint number
852 *
853 * Description:
854 *
855 * Return Value: On success, 1 is returned if the checkpoint specified by
856 * @cno is a snapshot, or 0 if not. On error, one of the following negative
857 * 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 */
865int nilfs_cpfile_is_snapshot(struct inode *cpfile, __u64 cno)
866{
867 struct buffer_head *bh;
868 struct nilfs_checkpoint *cp;
869 void *kaddr;
870 int ret;
871
872 /*
873 * CP number is invalid if it's zero or larger than the
874 * largest existing one.
875 */
876 if (cno == 0 || cno >= nilfs_mdt_cno(cpfile))
877 return -ENOENT;
878 down_read(&NILFS_MDT(cpfile)->mi_sem);
879
880 ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &bh);
881 if (ret < 0)
882 goto out;
883 kaddr = kmap_atomic(bh->b_page);
884 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr);
885 if (nilfs_checkpoint_invalid(cp))
886 ret = -ENOENT;
887 else
888 ret = nilfs_checkpoint_snapshot(cp);
889 kunmap_atomic(kaddr);
890 brelse(bh);
891
892 out:
893 up_read(&NILFS_MDT(cpfile)->mi_sem);
894 return ret;
895}
896
897/**
898 * nilfs_cpfile_change_cpmode - change checkpoint mode
899 * @cpfile: inode of checkpoint file
900 * @cno: checkpoint number
901 * @status: mode of checkpoint
902 *
903 * Description: nilfs_change_cpmode() changes the mode of the checkpoint
904 * specified by @cno. The mode @mode is NILFS_CHECKPOINT or NILFS_SNAPSHOT.
905 *
906 * Return Value: On success, 0 is returned. 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 * %-ENOENT - No such checkpoint.
914 */
915int nilfs_cpfile_change_cpmode(struct inode *cpfile, __u64 cno, int mode)
916{
917 int ret;
918
919 switch (mode) {
920 case NILFS_CHECKPOINT:
921 if (nilfs_checkpoint_is_mounted(cpfile->i_sb, cno))
922 /*
923 * Current implementation does not have to protect
924 * plain read-only mounts since they are exclusive
925 * with a read/write mount and are protected from the
926 * cleaner.
927 */
928 ret = -EBUSY;
929 else
930 ret = nilfs_cpfile_clear_snapshot(cpfile, cno);
931 return ret;
932 case NILFS_SNAPSHOT:
933 return nilfs_cpfile_set_snapshot(cpfile, cno);
934 default:
935 return -EINVAL;
936 }
937}
938
939/**
940 * nilfs_cpfile_get_stat - get checkpoint statistics
941 * @cpfile: inode of checkpoint file
942 * @stat: pointer to a structure of checkpoint statistics
943 *
944 * Description: nilfs_cpfile_get_stat() returns information about checkpoints.
945 *
946 * Return Value: On success, 0 is returned, and checkpoints information is
947 * stored in the place pointed by @stat. On error, one of the following
948 * negative error codes is returned.
949 *
950 * %-EIO - I/O error.
951 *
952 * %-ENOMEM - Insufficient amount of memory available.
953 */
954int nilfs_cpfile_get_stat(struct inode *cpfile, struct nilfs_cpstat *cpstat)
955{
956 struct buffer_head *bh;
957 struct nilfs_cpfile_header *header;
958 void *kaddr;
959 int ret;
960
961 down_read(&NILFS_MDT(cpfile)->mi_sem);
962
963 ret = nilfs_cpfile_get_header_block(cpfile, &bh);
964 if (ret < 0)
965 goto out_sem;
966 kaddr = kmap_atomic(bh->b_page);
967 header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr);
968 cpstat->cs_cno = nilfs_mdt_cno(cpfile);
969 cpstat->cs_ncps = le64_to_cpu(header->ch_ncheckpoints);
970 cpstat->cs_nsss = le64_to_cpu(header->ch_nsnapshots);
971 kunmap_atomic(kaddr);
972 brelse(bh);
973
974 out_sem:
975 up_read(&NILFS_MDT(cpfile)->mi_sem);
976 return ret;
977}
978
979/**
980 * nilfs_cpfile_read - read or get cpfile inode
981 * @sb: super block instance
982 * @cpsize: size of a checkpoint entry
983 * @raw_inode: on-disk cpfile inode
984 * @inodep: buffer to store the inode
985 */
986int nilfs_cpfile_read(struct super_block *sb, size_t cpsize,
987 struct nilfs_inode *raw_inode, struct inode **inodep)
988{
989 struct inode *cpfile;
990 int err;
991
992 if (cpsize > sb->s_blocksize) {
993 nilfs_msg(sb, KERN_ERR,
994 "too large checkpoint size: %zu bytes", cpsize);
995 return -EINVAL;
996 } else if (cpsize < NILFS_MIN_CHECKPOINT_SIZE) {
997 nilfs_msg(sb, KERN_ERR,
998 "too small checkpoint size: %zu bytes", cpsize);
999 return -EINVAL;
1000 }
1001
1002 cpfile = nilfs_iget_locked(sb, NULL, NILFS_CPFILE_INO);
1003 if (unlikely(!cpfile))
1004 return -ENOMEM;
1005 if (!(cpfile->i_state & I_NEW))
1006 goto out;
1007
1008 err = nilfs_mdt_init(cpfile, NILFS_MDT_GFP, 0);
1009 if (err)
1010 goto failed;
1011
1012 nilfs_mdt_set_entry_size(cpfile, cpsize,
1013 sizeof(struct nilfs_cpfile_header));
1014
1015 err = nilfs_read_inode_common(cpfile, raw_inode);
1016 if (err)
1017 goto failed;
1018
1019 unlock_new_inode(cpfile);
1020 out:
1021 *inodep = cpfile;
1022 return 0;
1023 failed:
1024 iget_failed(cpfile);
1025 return err;
1026}
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
33static inline unsigned long
34nilfs_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 */
40static unsigned long
41nilfs_cpfile_get_blkoff(const struct inode *cpfile, __u64 cno)
42{
43 __u64 tcno = cno + NILFS_MDT(cpfile)->mi_first_entry_offset - 1;
44 do_div(tcno, nilfs_cpfile_checkpoints_per_block(cpfile));
45 return (unsigned long)tcno;
46}
47
48/* offset in block */
49static unsigned long
50nilfs_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
56static unsigned long
57nilfs_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
67static 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
73static unsigned int
74nilfs_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
87static unsigned int
88nilfs_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
96 WARN_ON(le32_to_cpu(cp->cp_checkpoints_count) < n);
97 count = le32_to_cpu(cp->cp_checkpoints_count) - n;
98 cp->cp_checkpoints_count = cpu_to_le32(count);
99 return count;
100}
101
102static inline struct nilfs_cpfile_header *
103nilfs_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
110static struct nilfs_checkpoint *
111nilfs_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
119static 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
133static 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
139static 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
149static 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.
178 *
179 * %-EINVAL - invalid checkpoint.
180 */
181int 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
193 if (unlikely(cno < 1 || cno > nilfs_mdt_cno(cpfile) ||
194 (cno < nilfs_mdt_cno(cpfile) && create)))
195 return -EINVAL;
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 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 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 */
252void 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 */
278int 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 (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;
296 }
297
298 down_write(&NILFS_MDT(cpfile)->mi_sem);
299
300 ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
301 if (ret < 0)
302 goto out_sem;
303 tnicps = 0;
304
305 for (cno = start; cno < end; cno += ncps) {
306 ncps = nilfs_cpfile_checkpoints_in_block(cpfile, cno, end);
307 ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh);
308 if (ret < 0) {
309 if (ret != -ENOENT)
310 break;
311 /* skip hole */
312 ret = 0;
313 continue;
314 }
315
316 kaddr = kmap_atomic(cp_bh->b_page, KM_USER0);
317 cp = nilfs_cpfile_block_get_checkpoint(
318 cpfile, cno, cp_bh, kaddr);
319 nicps = 0;
320 for (i = 0; i < ncps; i++, cp = (void *)cp + cpsz) {
321 WARN_ON(nilfs_checkpoint_snapshot(cp));
322 if (!nilfs_checkpoint_invalid(cp)) {
323 nilfs_checkpoint_set_invalid(cp);
324 nicps++;
325 }
326 }
327 if (nicps > 0) {
328 tnicps += nicps;
329 mark_buffer_dirty(cp_bh);
330 nilfs_mdt_mark_dirty(cpfile);
331 if (!nilfs_cpfile_is_in_first(cpfile, cno)) {
332 count =
333 nilfs_cpfile_block_sub_valid_checkpoints(
334 cpfile, cp_bh, kaddr, nicps);
335 if (count == 0) {
336 /* make hole */
337 kunmap_atomic(kaddr, KM_USER0);
338 brelse(cp_bh);
339 ret =
340 nilfs_cpfile_delete_checkpoint_block(
341 cpfile, cno);
342 if (ret == 0)
343 continue;
344 printk(KERN_ERR
345 "%s: cannot delete block\n",
346 __func__);
347 break;
348 }
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);
360 le64_add_cpu(&header->ch_ncheckpoints, -(u64)tnicps);
361 mark_buffer_dirty(header_bh);
362 nilfs_mdt_mark_dirty(cpfile);
363 kunmap_atomic(kaddr, KM_USER0);
364 }
365
366 brelse(header_bh);
367
368 out_sem:
369 up_write(&NILFS_MDT(cpfile)->mi_sem);
370 return ret;
371}
372
373static 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
386static ssize_t nilfs_cpfile_do_get_cpinfo(struct inode *cpfile, __u64 *cnop,
387 void *buf, unsigned cisz, size_t nci)
388{
389 struct nilfs_checkpoint *cp;
390 struct nilfs_cpinfo *ci = buf;
391 struct buffer_head *bh;
392 size_t cpsz = NILFS_MDT(cpfile)->mi_entry_size;
393 __u64 cur_cno = nilfs_mdt_cno(cpfile), cno = *cnop;
394 void *kaddr;
395 int n, ret;
396 int ncps, i;
397
398 if (cno == 0)
399 return -ENOENT; /* checkpoint number 0 is invalid */
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) {
414 if (!nilfs_checkpoint_invalid(cp)) {
415 nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp,
416 ci);
417 ci = (void *)ci + cisz;
418 n++;
419 }
420 }
421 kunmap_atomic(kaddr, KM_USER0);
422 brelse(bh);
423 }
424
425 ret = n;
426 if (n > 0) {
427 ci = (void *)ci - cisz;
428 *cnop = ci->ci_cno + 1;
429 }
430
431 out:
432 up_read(&NILFS_MDT(cpfile)->mi_sem);
433 return ret;
434}
435
436static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 *cnop,
437 void *buf, unsigned cisz, size_t nci)
438{
439 struct buffer_head *bh;
440 struct nilfs_cpfile_header *header;
441 struct nilfs_checkpoint *cp;
442 struct nilfs_cpinfo *ci = buf;
443 __u64 curr = *cnop, next;
444 unsigned long curr_blkoff, next_blkoff;
445 void *kaddr;
446 int n = 0, ret;
447
448 down_read(&NILFS_MDT(cpfile)->mi_sem);
449
450 if (curr == 0) {
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 }
463 } else if (unlikely(curr == ~(__u64)0)) {
464 ret = 0;
465 goto out;
466 }
467
468 curr_blkoff = nilfs_cpfile_get_blkoff(cpfile, curr);
469 ret = nilfs_cpfile_get_checkpoint_block(cpfile, curr, 0, &bh);
470 if (unlikely(ret < 0)) {
471 if (ret == -ENOENT)
472 ret = 0; /* No snapshots (started from a hole block) */
473 goto out;
474 }
475 kaddr = kmap_atomic(bh->b_page, KM_USER0);
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)))
481 break;
482 nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp, ci);
483 ci = (void *)ci + cisz;
484 n++;
485 next = le64_to_cpu(cp->cp_snapshot_list.ssl_next);
486 if (next == 0)
487 break; /* reach end of the snapshot list */
488
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);
495 if (unlikely(ret < 0)) {
496 WARN_ON(ret == -ENOENT);
497 goto out;
498 }
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);
506 *cnop = curr;
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 */
521
522ssize_t nilfs_cpfile_get_cpinfo(struct inode *cpfile, __u64 *cnop, int mode,
523 void *buf, unsigned cisz, size_t nci)
524{
525 switch (mode) {
526 case NILFS_CHECKPOINT:
527 return nilfs_cpfile_do_get_cpinfo(cpfile, cnop, buf, cisz, nci);
528 case NILFS_SNAPSHOT:
529 return nilfs_cpfile_do_get_ssinfo(cpfile, cnop, buf, cisz, nci);
530 default:
531 return -EINVAL;
532 }
533}
534
535/**
536 * nilfs_cpfile_delete_checkpoint -
537 * @cpfile:
538 * @cno:
539 */
540int nilfs_cpfile_delete_checkpoint(struct inode *cpfile, __u64 cno)
541{
542 struct nilfs_cpinfo ci;
543 __u64 tcno = cno;
544 ssize_t nci;
545
546 nci = nilfs_cpfile_do_get_cpinfo(cpfile, &tcno, &ci, sizeof(ci), 1);
547 if (nci < 0)
548 return nci;
549 else if (nci == 0 || ci.ci_cno != cno)
550 return -ENOENT;
551 else if (nilfs_cpinfo_snapshot(&ci))
552 return -EBUSY;
553
554 return nilfs_cpfile_delete_checkpoints(cpfile, cno, cno + 1);
555}
556
557static struct nilfs_snapshot_list *
558nilfs_cpfile_block_get_snapshot_list(const struct inode *cpfile,
559 __u64 cno,
560 struct buffer_head *bh,
561 void *kaddr)
562{
563 struct nilfs_cpfile_header *header;
564 struct nilfs_checkpoint *cp;
565 struct nilfs_snapshot_list *list;
566
567 if (cno != 0) {
568 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr);
569 list = &cp->cp_snapshot_list;
570 } else {
571 header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr);
572 list = &header->ch_snapshot_list;
573 }
574 return list;
575}
576
577static int nilfs_cpfile_set_snapshot(struct inode *cpfile, __u64 cno)
578{
579 struct buffer_head *header_bh, *curr_bh, *prev_bh, *cp_bh;
580 struct nilfs_cpfile_header *header;
581 struct nilfs_checkpoint *cp;
582 struct nilfs_snapshot_list *list;
583 __u64 curr, prev;
584 unsigned long curr_blkoff, prev_blkoff;
585 void *kaddr;
586 int ret;
587
588 if (cno == 0)
589 return -ENOENT; /* checkpoint number 0 is invalid */
590 down_write(&NILFS_MDT(cpfile)->mi_sem);
591
592 ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh);
593 if (ret < 0)
594 goto out_sem;
595 kaddr = kmap_atomic(cp_bh->b_page, KM_USER0);
596 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
597 if (nilfs_checkpoint_invalid(cp)) {
598 ret = -ENOENT;
599 kunmap_atomic(kaddr, KM_USER0);
600 goto out_cp;
601 }
602 if (nilfs_checkpoint_snapshot(cp)) {
603 ret = 0;
604 kunmap_atomic(kaddr, KM_USER0);
605 goto out_cp;
606 }
607 kunmap_atomic(kaddr, KM_USER0);
608
609 ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
610 if (ret < 0)
611 goto out_cp;
612 kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
613 header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr);
614 list = &header->ch_snapshot_list;
615 curr_bh = header_bh;
616 get_bh(curr_bh);
617 curr = 0;
618 curr_blkoff = 0;
619 prev = le64_to_cpu(list->ssl_prev);
620 while (prev > cno) {
621 prev_blkoff = nilfs_cpfile_get_blkoff(cpfile, prev);
622 curr = prev;
623 if (curr_blkoff != prev_blkoff) {
624 kunmap_atomic(kaddr, KM_USER0);
625 brelse(curr_bh);
626 ret = nilfs_cpfile_get_checkpoint_block(cpfile, curr,
627 0, &curr_bh);
628 if (ret < 0)
629 goto out_header;
630 kaddr = kmap_atomic(curr_bh->b_page, KM_USER0);
631 }
632 curr_blkoff = prev_blkoff;
633 cp = nilfs_cpfile_block_get_checkpoint(
634 cpfile, curr, curr_bh, kaddr);
635 list = &cp->cp_snapshot_list;
636 prev = le64_to_cpu(list->ssl_prev);
637 }
638 kunmap_atomic(kaddr, KM_USER0);
639
640 if (prev != 0) {
641 ret = nilfs_cpfile_get_checkpoint_block(cpfile, prev, 0,
642 &prev_bh);
643 if (ret < 0)
644 goto out_curr;
645 } else {
646 prev_bh = header_bh;
647 get_bh(prev_bh);
648 }
649
650 kaddr = kmap_atomic(curr_bh->b_page, KM_USER0);
651 list = nilfs_cpfile_block_get_snapshot_list(
652 cpfile, curr, curr_bh, kaddr);
653 list->ssl_prev = cpu_to_le64(cno);
654 kunmap_atomic(kaddr, KM_USER0);
655
656 kaddr = kmap_atomic(cp_bh->b_page, KM_USER0);
657 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
658 cp->cp_snapshot_list.ssl_next = cpu_to_le64(curr);
659 cp->cp_snapshot_list.ssl_prev = cpu_to_le64(prev);
660 nilfs_checkpoint_set_snapshot(cp);
661 kunmap_atomic(kaddr, KM_USER0);
662
663 kaddr = kmap_atomic(prev_bh->b_page, KM_USER0);
664 list = nilfs_cpfile_block_get_snapshot_list(
665 cpfile, prev, prev_bh, kaddr);
666 list->ssl_next = cpu_to_le64(cno);
667 kunmap_atomic(kaddr, KM_USER0);
668
669 kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
670 header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr);
671 le64_add_cpu(&header->ch_nsnapshots, 1);
672 kunmap_atomic(kaddr, KM_USER0);
673
674 mark_buffer_dirty(prev_bh);
675 mark_buffer_dirty(curr_bh);
676 mark_buffer_dirty(cp_bh);
677 mark_buffer_dirty(header_bh);
678 nilfs_mdt_mark_dirty(cpfile);
679
680 brelse(prev_bh);
681
682 out_curr:
683 brelse(curr_bh);
684
685 out_header:
686 brelse(header_bh);
687
688 out_cp:
689 brelse(cp_bh);
690
691 out_sem:
692 up_write(&NILFS_MDT(cpfile)->mi_sem);
693 return ret;
694}
695
696static int nilfs_cpfile_clear_snapshot(struct inode *cpfile, __u64 cno)
697{
698 struct buffer_head *header_bh, *next_bh, *prev_bh, *cp_bh;
699 struct nilfs_cpfile_header *header;
700 struct nilfs_checkpoint *cp;
701 struct nilfs_snapshot_list *list;
702 __u64 next, prev;
703 void *kaddr;
704 int ret;
705
706 if (cno == 0)
707 return -ENOENT; /* checkpoint number 0 is invalid */
708 down_write(&NILFS_MDT(cpfile)->mi_sem);
709
710 ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh);
711 if (ret < 0)
712 goto out_sem;
713 kaddr = kmap_atomic(cp_bh->b_page, KM_USER0);
714 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
715 if (nilfs_checkpoint_invalid(cp)) {
716 ret = -ENOENT;
717 kunmap_atomic(kaddr, KM_USER0);
718 goto out_cp;
719 }
720 if (!nilfs_checkpoint_snapshot(cp)) {
721 ret = 0;
722 kunmap_atomic(kaddr, KM_USER0);
723 goto out_cp;
724 }
725
726 list = &cp->cp_snapshot_list;
727 next = le64_to_cpu(list->ssl_next);
728 prev = le64_to_cpu(list->ssl_prev);
729 kunmap_atomic(kaddr, KM_USER0);
730
731 ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
732 if (ret < 0)
733 goto out_cp;
734 if (next != 0) {
735 ret = nilfs_cpfile_get_checkpoint_block(cpfile, next, 0,
736 &next_bh);
737 if (ret < 0)
738 goto out_header;
739 } else {
740 next_bh = header_bh;
741 get_bh(next_bh);
742 }
743 if (prev != 0) {
744 ret = nilfs_cpfile_get_checkpoint_block(cpfile, prev, 0,
745 &prev_bh);
746 if (ret < 0)
747 goto out_next;
748 } else {
749 prev_bh = header_bh;
750 get_bh(prev_bh);
751 }
752
753 kaddr = kmap_atomic(next_bh->b_page, KM_USER0);
754 list = nilfs_cpfile_block_get_snapshot_list(
755 cpfile, next, next_bh, kaddr);
756 list->ssl_prev = cpu_to_le64(prev);
757 kunmap_atomic(kaddr, KM_USER0);
758
759 kaddr = kmap_atomic(prev_bh->b_page, KM_USER0);
760 list = nilfs_cpfile_block_get_snapshot_list(
761 cpfile, prev, prev_bh, kaddr);
762 list->ssl_next = cpu_to_le64(next);
763 kunmap_atomic(kaddr, KM_USER0);
764
765 kaddr = kmap_atomic(cp_bh->b_page, KM_USER0);
766 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
767 cp->cp_snapshot_list.ssl_next = cpu_to_le64(0);
768 cp->cp_snapshot_list.ssl_prev = cpu_to_le64(0);
769 nilfs_checkpoint_clear_snapshot(cp);
770 kunmap_atomic(kaddr, KM_USER0);
771
772 kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
773 header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr);
774 le64_add_cpu(&header->ch_nsnapshots, -1);
775 kunmap_atomic(kaddr, KM_USER0);
776
777 mark_buffer_dirty(next_bh);
778 mark_buffer_dirty(prev_bh);
779 mark_buffer_dirty(cp_bh);
780 mark_buffer_dirty(header_bh);
781 nilfs_mdt_mark_dirty(cpfile);
782
783 brelse(prev_bh);
784
785 out_next:
786 brelse(next_bh);
787
788 out_header:
789 brelse(header_bh);
790
791 out_cp:
792 brelse(cp_bh);
793
794 out_sem:
795 up_write(&NILFS_MDT(cpfile)->mi_sem);
796 return ret;
797}
798
799/**
800 * nilfs_cpfile_is_snapshot -
801 * @cpfile: inode of checkpoint file
802 * @cno: checkpoint number
803 *
804 * Description:
805 *
806 * Return Value: On success, 1 is returned if the checkpoint specified by
807 * @cno is a snapshot, or 0 if not. On error, one of the following negative
808 * error codes is returned.
809 *
810 * %-EIO - I/O error.
811 *
812 * %-ENOMEM - Insufficient amount of memory available.
813 *
814 * %-ENOENT - No such checkpoint.
815 */
816int nilfs_cpfile_is_snapshot(struct inode *cpfile, __u64 cno)
817{
818 struct buffer_head *bh;
819 struct nilfs_checkpoint *cp;
820 void *kaddr;
821 int ret;
822
823 /* CP number is invalid if it's zero or larger than the
824 largest exist one.*/
825 if (cno == 0 || cno >= nilfs_mdt_cno(cpfile))
826 return -ENOENT;
827 down_read(&NILFS_MDT(cpfile)->mi_sem);
828
829 ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &bh);
830 if (ret < 0)
831 goto out;
832 kaddr = kmap_atomic(bh->b_page, KM_USER0);
833 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr);
834 if (nilfs_checkpoint_invalid(cp))
835 ret = -ENOENT;
836 else
837 ret = nilfs_checkpoint_snapshot(cp);
838 kunmap_atomic(kaddr, KM_USER0);
839 brelse(bh);
840
841 out:
842 up_read(&NILFS_MDT(cpfile)->mi_sem);
843 return ret;
844}
845
846/**
847 * nilfs_cpfile_change_cpmode - change checkpoint mode
848 * @cpfile: inode of checkpoint file
849 * @cno: checkpoint number
850 * @status: mode of checkpoint
851 *
852 * Description: nilfs_change_cpmode() changes the mode of the checkpoint
853 * specified by @cno. The mode @mode is NILFS_CHECKPOINT or NILFS_SNAPSHOT.
854 *
855 * Return Value: On success, 0 is returned. On error, one of the following
856 * negative error codes is returned.
857 *
858 * %-EIO - I/O error.
859 *
860 * %-ENOMEM - Insufficient amount of memory available.
861 *
862 * %-ENOENT - No such checkpoint.
863 */
864int nilfs_cpfile_change_cpmode(struct inode *cpfile, __u64 cno, int mode)
865{
866 int ret;
867
868 switch (mode) {
869 case NILFS_CHECKPOINT:
870 if (nilfs_checkpoint_is_mounted(cpfile->i_sb, cno))
871 /*
872 * Current implementation does not have to protect
873 * plain read-only mounts since they are exclusive
874 * with a read/write mount and are protected from the
875 * cleaner.
876 */
877 ret = -EBUSY;
878 else
879 ret = nilfs_cpfile_clear_snapshot(cpfile, cno);
880 return ret;
881 case NILFS_SNAPSHOT:
882 return nilfs_cpfile_set_snapshot(cpfile, cno);
883 default:
884 return -EINVAL;
885 }
886}
887
888/**
889 * nilfs_cpfile_get_stat - get checkpoint statistics
890 * @cpfile: inode of checkpoint file
891 * @stat: pointer to a structure of checkpoint statistics
892 *
893 * Description: nilfs_cpfile_get_stat() returns information about checkpoints.
894 *
895 * Return Value: On success, 0 is returned, and checkpoints information is
896 * stored in the place pointed by @stat. On error, one of the following
897 * negative error codes is returned.
898 *
899 * %-EIO - I/O error.
900 *
901 * %-ENOMEM - Insufficient amount of memory available.
902 */
903int nilfs_cpfile_get_stat(struct inode *cpfile, struct nilfs_cpstat *cpstat)
904{
905 struct buffer_head *bh;
906 struct nilfs_cpfile_header *header;
907 void *kaddr;
908 int ret;
909
910 down_read(&NILFS_MDT(cpfile)->mi_sem);
911
912 ret = nilfs_cpfile_get_header_block(cpfile, &bh);
913 if (ret < 0)
914 goto out_sem;
915 kaddr = kmap_atomic(bh->b_page, KM_USER0);
916 header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr);
917 cpstat->cs_cno = nilfs_mdt_cno(cpfile);
918 cpstat->cs_ncps = le64_to_cpu(header->ch_ncheckpoints);
919 cpstat->cs_nsss = le64_to_cpu(header->ch_nsnapshots);
920 kunmap_atomic(kaddr, KM_USER0);
921 brelse(bh);
922
923 out_sem:
924 up_read(&NILFS_MDT(cpfile)->mi_sem);
925 return ret;
926}
927
928/**
929 * nilfs_cpfile_read - read or get cpfile inode
930 * @sb: super block instance
931 * @cpsize: size of a checkpoint entry
932 * @raw_inode: on-disk cpfile inode
933 * @inodep: buffer to store the inode
934 */
935int nilfs_cpfile_read(struct super_block *sb, size_t cpsize,
936 struct nilfs_inode *raw_inode, struct inode **inodep)
937{
938 struct inode *cpfile;
939 int err;
940
941 cpfile = nilfs_iget_locked(sb, NULL, NILFS_CPFILE_INO);
942 if (unlikely(!cpfile))
943 return -ENOMEM;
944 if (!(cpfile->i_state & I_NEW))
945 goto out;
946
947 err = nilfs_mdt_init(cpfile, NILFS_MDT_GFP, 0);
948 if (err)
949 goto failed;
950
951 nilfs_mdt_set_entry_size(cpfile, cpsize,
952 sizeof(struct nilfs_cpfile_header));
953
954 err = nilfs_read_inode_common(cpfile, raw_inode);
955 if (err)
956 goto failed;
957
958 unlock_new_inode(cpfile);
959 out:
960 *inodep = cpfile;
961 return 0;
962 failed:
963 iget_failed(cpfile);
964 return err;
965}