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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
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
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}
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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
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);
222 header = nilfs_cpfile_block_get_header(cpfile, header_bh,
223 kaddr);
224 le64_add_cpu(&header->ch_ncheckpoints, 1);
225 kunmap_atomic(kaddr);
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
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250
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}
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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, nss, 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 nss = 0;
305
306 for (cno = start; cno < end; cno += ncps) {
307 ncps = nilfs_cpfile_checkpoints_in_block(cpfile, cno, end);
308 ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh);
309 if (ret < 0) {
310 if (ret != -ENOENT)
311 break;
312
313 ret = 0;
314 continue;
315 }
316
317 kaddr = kmap_atomic(cp_bh->b_page);
318 cp = nilfs_cpfile_block_get_checkpoint(
319 cpfile, cno, cp_bh, kaddr);
320 nicps = 0;
321 for (i = 0; i < ncps; i++, cp = (void *)cp + cpsz) {
322 if (nilfs_checkpoint_snapshot(cp)) {
323 nss++;
324 } else if (!nilfs_checkpoint_invalid(cp)) {
325 nilfs_checkpoint_set_invalid(cp);
326 nicps++;
327 }
328 }
329 if (nicps > 0) {
330 tnicps += nicps;
331 mark_buffer_dirty(cp_bh);
332 nilfs_mdt_mark_dirty(cpfile);
333 if (!nilfs_cpfile_is_in_first(cpfile, cno)) {
334 count =
335 nilfs_cpfile_block_sub_valid_checkpoints(
336 cpfile, cp_bh, kaddr, nicps);
337 if (count == 0) {
338
339 kunmap_atomic(kaddr);
340 brelse(cp_bh);
341 ret =
342 nilfs_cpfile_delete_checkpoint_block(
343 cpfile, cno);
344 if (ret == 0)
345 continue;
346 printk(KERN_ERR
347 "%s: cannot delete block\n",
348 __func__);
349 break;
350 }
351 }
352 }
353
354 kunmap_atomic(kaddr);
355 brelse(cp_bh);
356 }
357
358 if (tnicps > 0) {
359 kaddr = kmap_atomic(header_bh->b_page);
360 header = nilfs_cpfile_block_get_header(cpfile, header_bh,
361 kaddr);
362 le64_add_cpu(&header->ch_ncheckpoints, -(u64)tnicps);
363 mark_buffer_dirty(header_bh);
364 nilfs_mdt_mark_dirty(cpfile);
365 kunmap_atomic(kaddr);
366 }
367
368 brelse(header_bh);
369 if (nss > 0)
370 ret = -EBUSY;
371
372 out_sem:
373 up_write(&NILFS_MDT(cpfile)->mi_sem);
374 return ret;
375}
376
377static void nilfs_cpfile_checkpoint_to_cpinfo(struct inode *cpfile,
378 struct nilfs_checkpoint *cp,
379 struct nilfs_cpinfo *ci)
380{
381 ci->ci_flags = le32_to_cpu(cp->cp_flags);
382 ci->ci_cno = le64_to_cpu(cp->cp_cno);
383 ci->ci_create = le64_to_cpu(cp->cp_create);
384 ci->ci_nblk_inc = le64_to_cpu(cp->cp_nblk_inc);
385 ci->ci_inodes_count = le64_to_cpu(cp->cp_inodes_count);
386 ci->ci_blocks_count = le64_to_cpu(cp->cp_blocks_count);
387 ci->ci_next = le64_to_cpu(cp->cp_snapshot_list.ssl_next);
388}
389
390static ssize_t nilfs_cpfile_do_get_cpinfo(struct inode *cpfile, __u64 *cnop,
391 void *buf, unsigned cisz, size_t nci)
392{
393 struct nilfs_checkpoint *cp;
394 struct nilfs_cpinfo *ci = buf;
395 struct buffer_head *bh;
396 size_t cpsz = NILFS_MDT(cpfile)->mi_entry_size;
397 __u64 cur_cno = nilfs_mdt_cno(cpfile), cno = *cnop;
398 void *kaddr;
399 int n, ret;
400 int ncps, i;
401
402 if (cno == 0)
403 return -ENOENT;
404 down_read(&NILFS_MDT(cpfile)->mi_sem);
405
406 for (n = 0; cno < cur_cno && n < nci; cno += ncps) {
407 ncps = nilfs_cpfile_checkpoints_in_block(cpfile, cno, cur_cno);
408 ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &bh);
409 if (ret < 0) {
410 if (ret != -ENOENT)
411 goto out;
412 continue;
413 }
414
415 kaddr = kmap_atomic(bh->b_page);
416 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr);
417 for (i = 0; i < ncps && n < nci; i++, cp = (void *)cp + cpsz) {
418 if (!nilfs_checkpoint_invalid(cp)) {
419 nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp,
420 ci);
421 ci = (void *)ci + cisz;
422 n++;
423 }
424 }
425 kunmap_atomic(kaddr);
426 brelse(bh);
427 }
428
429 ret = n;
430 if (n > 0) {
431 ci = (void *)ci - cisz;
432 *cnop = ci->ci_cno + 1;
433 }
434
435 out:
436 up_read(&NILFS_MDT(cpfile)->mi_sem);
437 return ret;
438}
439
440static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 *cnop,
441 void *buf, unsigned cisz, size_t nci)
442{
443 struct buffer_head *bh;
444 struct nilfs_cpfile_header *header;
445 struct nilfs_checkpoint *cp;
446 struct nilfs_cpinfo *ci = buf;
447 __u64 curr = *cnop, next;
448 unsigned long curr_blkoff, next_blkoff;
449 void *kaddr;
450 int n = 0, ret;
451
452 down_read(&NILFS_MDT(cpfile)->mi_sem);
453
454 if (curr == 0) {
455 ret = nilfs_cpfile_get_header_block(cpfile, &bh);
456 if (ret < 0)
457 goto out;
458 kaddr = kmap_atomic(bh->b_page);
459 header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr);
460 curr = le64_to_cpu(header->ch_snapshot_list.ssl_next);
461 kunmap_atomic(kaddr);
462 brelse(bh);
463 if (curr == 0) {
464 ret = 0;
465 goto out;
466 }
467 } else if (unlikely(curr == ~(__u64)0)) {
468 ret = 0;
469 goto out;
470 }
471
472 curr_blkoff = nilfs_cpfile_get_blkoff(cpfile, curr);
473 ret = nilfs_cpfile_get_checkpoint_block(cpfile, curr, 0, &bh);
474 if (unlikely(ret < 0)) {
475 if (ret == -ENOENT)
476 ret = 0;
477 goto out;
478 }
479 kaddr = kmap_atomic(bh->b_page);
480 while (n < nci) {
481 cp = nilfs_cpfile_block_get_checkpoint(cpfile, curr, bh, kaddr);
482 curr = ~(__u64)0;
483 if (unlikely(nilfs_checkpoint_invalid(cp) ||
484 !nilfs_checkpoint_snapshot(cp)))
485 break;
486 nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp, ci);
487 ci = (void *)ci + cisz;
488 n++;
489 next = le64_to_cpu(cp->cp_snapshot_list.ssl_next);
490 if (next == 0)
491 break;
492
493 next_blkoff = nilfs_cpfile_get_blkoff(cpfile, next);
494 if (curr_blkoff != next_blkoff) {
495 kunmap_atomic(kaddr);
496 brelse(bh);
497 ret = nilfs_cpfile_get_checkpoint_block(cpfile, next,
498 0, &bh);
499 if (unlikely(ret < 0)) {
500 WARN_ON(ret == -ENOENT);
501 goto out;
502 }
503 kaddr = kmap_atomic(bh->b_page);
504 }
505 curr = next;
506 curr_blkoff = next_blkoff;
507 }
508 kunmap_atomic(kaddr);
509 brelse(bh);
510 *cnop = curr;
511 ret = n;
512
513 out:
514 up_read(&NILFS_MDT(cpfile)->mi_sem);
515 return ret;
516}
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526ssize_t nilfs_cpfile_get_cpinfo(struct inode *cpfile, __u64 *cnop, int mode,
527 void *buf, unsigned cisz, size_t nci)
528{
529 switch (mode) {
530 case NILFS_CHECKPOINT:
531 return nilfs_cpfile_do_get_cpinfo(cpfile, cnop, buf, cisz, nci);
532 case NILFS_SNAPSHOT:
533 return nilfs_cpfile_do_get_ssinfo(cpfile, cnop, buf, cisz, nci);
534 default:
535 return -EINVAL;
536 }
537}
538
539
540
541
542
543
544int nilfs_cpfile_delete_checkpoint(struct inode *cpfile, __u64 cno)
545{
546 struct nilfs_cpinfo ci;
547 __u64 tcno = cno;
548 ssize_t nci;
549
550 nci = nilfs_cpfile_do_get_cpinfo(cpfile, &tcno, &ci, sizeof(ci), 1);
551 if (nci < 0)
552 return nci;
553 else if (nci == 0 || ci.ci_cno != cno)
554 return -ENOENT;
555 else if (nilfs_cpinfo_snapshot(&ci))
556 return -EBUSY;
557
558 return nilfs_cpfile_delete_checkpoints(cpfile, cno, cno + 1);
559}
560
561static struct nilfs_snapshot_list *
562nilfs_cpfile_block_get_snapshot_list(const struct inode *cpfile,
563 __u64 cno,
564 struct buffer_head *bh,
565 void *kaddr)
566{
567 struct nilfs_cpfile_header *header;
568 struct nilfs_checkpoint *cp;
569 struct nilfs_snapshot_list *list;
570
571 if (cno != 0) {
572 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr);
573 list = &cp->cp_snapshot_list;
574 } else {
575 header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr);
576 list = &header->ch_snapshot_list;
577 }
578 return list;
579}
580
581static int nilfs_cpfile_set_snapshot(struct inode *cpfile, __u64 cno)
582{
583 struct buffer_head *header_bh, *curr_bh, *prev_bh, *cp_bh;
584 struct nilfs_cpfile_header *header;
585 struct nilfs_checkpoint *cp;
586 struct nilfs_snapshot_list *list;
587 __u64 curr, prev;
588 unsigned long curr_blkoff, prev_blkoff;
589 void *kaddr;
590 int ret;
591
592 if (cno == 0)
593 return -ENOENT;
594 down_write(&NILFS_MDT(cpfile)->mi_sem);
595
596 ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh);
597 if (ret < 0)
598 goto out_sem;
599 kaddr = kmap_atomic(cp_bh->b_page);
600 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
601 if (nilfs_checkpoint_invalid(cp)) {
602 ret = -ENOENT;
603 kunmap_atomic(kaddr);
604 goto out_cp;
605 }
606 if (nilfs_checkpoint_snapshot(cp)) {
607 ret = 0;
608 kunmap_atomic(kaddr);
609 goto out_cp;
610 }
611 kunmap_atomic(kaddr);
612
613 ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
614 if (ret < 0)
615 goto out_cp;
616 kaddr = kmap_atomic(header_bh->b_page);
617 header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr);
618 list = &header->ch_snapshot_list;
619 curr_bh = header_bh;
620 get_bh(curr_bh);
621 curr = 0;
622 curr_blkoff = 0;
623 prev = le64_to_cpu(list->ssl_prev);
624 while (prev > cno) {
625 prev_blkoff = nilfs_cpfile_get_blkoff(cpfile, prev);
626 curr = prev;
627 if (curr_blkoff != prev_blkoff) {
628 kunmap_atomic(kaddr);
629 brelse(curr_bh);
630 ret = nilfs_cpfile_get_checkpoint_block(cpfile, curr,
631 0, &curr_bh);
632 if (ret < 0)
633 goto out_header;
634 kaddr = kmap_atomic(curr_bh->b_page);
635 }
636 curr_blkoff = prev_blkoff;
637 cp = nilfs_cpfile_block_get_checkpoint(
638 cpfile, curr, curr_bh, kaddr);
639 list = &cp->cp_snapshot_list;
640 prev = le64_to_cpu(list->ssl_prev);
641 }
642 kunmap_atomic(kaddr);
643
644 if (prev != 0) {
645 ret = nilfs_cpfile_get_checkpoint_block(cpfile, prev, 0,
646 &prev_bh);
647 if (ret < 0)
648 goto out_curr;
649 } else {
650 prev_bh = header_bh;
651 get_bh(prev_bh);
652 }
653
654 kaddr = kmap_atomic(curr_bh->b_page);
655 list = nilfs_cpfile_block_get_snapshot_list(
656 cpfile, curr, curr_bh, kaddr);
657 list->ssl_prev = cpu_to_le64(cno);
658 kunmap_atomic(kaddr);
659
660 kaddr = kmap_atomic(cp_bh->b_page);
661 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
662 cp->cp_snapshot_list.ssl_next = cpu_to_le64(curr);
663 cp->cp_snapshot_list.ssl_prev = cpu_to_le64(prev);
664 nilfs_checkpoint_set_snapshot(cp);
665 kunmap_atomic(kaddr);
666
667 kaddr = kmap_atomic(prev_bh->b_page);
668 list = nilfs_cpfile_block_get_snapshot_list(
669 cpfile, prev, prev_bh, kaddr);
670 list->ssl_next = cpu_to_le64(cno);
671 kunmap_atomic(kaddr);
672
673 kaddr = kmap_atomic(header_bh->b_page);
674 header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr);
675 le64_add_cpu(&header->ch_nsnapshots, 1);
676 kunmap_atomic(kaddr);
677
678 mark_buffer_dirty(prev_bh);
679 mark_buffer_dirty(curr_bh);
680 mark_buffer_dirty(cp_bh);
681 mark_buffer_dirty(header_bh);
682 nilfs_mdt_mark_dirty(cpfile);
683
684 brelse(prev_bh);
685
686 out_curr:
687 brelse(curr_bh);
688
689 out_header:
690 brelse(header_bh);
691
692 out_cp:
693 brelse(cp_bh);
694
695 out_sem:
696 up_write(&NILFS_MDT(cpfile)->mi_sem);
697 return ret;
698}
699
700static int nilfs_cpfile_clear_snapshot(struct inode *cpfile, __u64 cno)
701{
702 struct buffer_head *header_bh, *next_bh, *prev_bh, *cp_bh;
703 struct nilfs_cpfile_header *header;
704 struct nilfs_checkpoint *cp;
705 struct nilfs_snapshot_list *list;
706 __u64 next, prev;
707 void *kaddr;
708 int ret;
709
710 if (cno == 0)
711 return -ENOENT;
712 down_write(&NILFS_MDT(cpfile)->mi_sem);
713
714 ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh);
715 if (ret < 0)
716 goto out_sem;
717 kaddr = kmap_atomic(cp_bh->b_page);
718 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
719 if (nilfs_checkpoint_invalid(cp)) {
720 ret = -ENOENT;
721 kunmap_atomic(kaddr);
722 goto out_cp;
723 }
724 if (!nilfs_checkpoint_snapshot(cp)) {
725 ret = 0;
726 kunmap_atomic(kaddr);
727 goto out_cp;
728 }
729
730 list = &cp->cp_snapshot_list;
731 next = le64_to_cpu(list->ssl_next);
732 prev = le64_to_cpu(list->ssl_prev);
733 kunmap_atomic(kaddr);
734
735 ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
736 if (ret < 0)
737 goto out_cp;
738 if (next != 0) {
739 ret = nilfs_cpfile_get_checkpoint_block(cpfile, next, 0,
740 &next_bh);
741 if (ret < 0)
742 goto out_header;
743 } else {
744 next_bh = header_bh;
745 get_bh(next_bh);
746 }
747 if (prev != 0) {
748 ret = nilfs_cpfile_get_checkpoint_block(cpfile, prev, 0,
749 &prev_bh);
750 if (ret < 0)
751 goto out_next;
752 } else {
753 prev_bh = header_bh;
754 get_bh(prev_bh);
755 }
756
757 kaddr = kmap_atomic(next_bh->b_page);
758 list = nilfs_cpfile_block_get_snapshot_list(
759 cpfile, next, next_bh, kaddr);
760 list->ssl_prev = cpu_to_le64(prev);
761 kunmap_atomic(kaddr);
762
763 kaddr = kmap_atomic(prev_bh->b_page);
764 list = nilfs_cpfile_block_get_snapshot_list(
765 cpfile, prev, prev_bh, kaddr);
766 list->ssl_next = cpu_to_le64(next);
767 kunmap_atomic(kaddr);
768
769 kaddr = kmap_atomic(cp_bh->b_page);
770 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
771 cp->cp_snapshot_list.ssl_next = cpu_to_le64(0);
772 cp->cp_snapshot_list.ssl_prev = cpu_to_le64(0);
773 nilfs_checkpoint_clear_snapshot(cp);
774 kunmap_atomic(kaddr);
775
776 kaddr = kmap_atomic(header_bh->b_page);
777 header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr);
778 le64_add_cpu(&header->ch_nsnapshots, -1);
779 kunmap_atomic(kaddr);
780
781 mark_buffer_dirty(next_bh);
782 mark_buffer_dirty(prev_bh);
783 mark_buffer_dirty(cp_bh);
784 mark_buffer_dirty(header_bh);
785 nilfs_mdt_mark_dirty(cpfile);
786
787 brelse(prev_bh);
788
789 out_next:
790 brelse(next_bh);
791
792 out_header:
793 brelse(header_bh);
794
795 out_cp:
796 brelse(cp_bh);
797
798 out_sem:
799 up_write(&NILFS_MDT(cpfile)->mi_sem);
800 return ret;
801}
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820int nilfs_cpfile_is_snapshot(struct inode *cpfile, __u64 cno)
821{
822 struct buffer_head *bh;
823 struct nilfs_checkpoint *cp;
824 void *kaddr;
825 int ret;
826
827
828
829 if (cno == 0 || cno >= nilfs_mdt_cno(cpfile))
830 return -ENOENT;
831 down_read(&NILFS_MDT(cpfile)->mi_sem);
832
833 ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &bh);
834 if (ret < 0)
835 goto out;
836 kaddr = kmap_atomic(bh->b_page);
837 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr);
838 if (nilfs_checkpoint_invalid(cp))
839 ret = -ENOENT;
840 else
841 ret = nilfs_checkpoint_snapshot(cp);
842 kunmap_atomic(kaddr);
843 brelse(bh);
844
845 out:
846 up_read(&NILFS_MDT(cpfile)->mi_sem);
847 return ret;
848}
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868int nilfs_cpfile_change_cpmode(struct inode *cpfile, __u64 cno, int mode)
869{
870 int ret;
871
872 switch (mode) {
873 case NILFS_CHECKPOINT:
874 if (nilfs_checkpoint_is_mounted(cpfile->i_sb, cno))
875
876
877
878
879
880
881 ret = -EBUSY;
882 else
883 ret = nilfs_cpfile_clear_snapshot(cpfile, cno);
884 return ret;
885 case NILFS_SNAPSHOT:
886 return nilfs_cpfile_set_snapshot(cpfile, cno);
887 default:
888 return -EINVAL;
889 }
890}
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907int nilfs_cpfile_get_stat(struct inode *cpfile, struct nilfs_cpstat *cpstat)
908{
909 struct buffer_head *bh;
910 struct nilfs_cpfile_header *header;
911 void *kaddr;
912 int ret;
913
914 down_read(&NILFS_MDT(cpfile)->mi_sem);
915
916 ret = nilfs_cpfile_get_header_block(cpfile, &bh);
917 if (ret < 0)
918 goto out_sem;
919 kaddr = kmap_atomic(bh->b_page);
920 header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr);
921 cpstat->cs_cno = nilfs_mdt_cno(cpfile);
922 cpstat->cs_ncps = le64_to_cpu(header->ch_ncheckpoints);
923 cpstat->cs_nsss = le64_to_cpu(header->ch_nsnapshots);
924 kunmap_atomic(kaddr);
925 brelse(bh);
926
927 out_sem:
928 up_read(&NILFS_MDT(cpfile)->mi_sem);
929 return ret;
930}
931
932
933
934
935
936
937
938
939int nilfs_cpfile_read(struct super_block *sb, size_t cpsize,
940 struct nilfs_inode *raw_inode, struct inode **inodep)
941{
942 struct inode *cpfile;
943 int err;
944
945 cpfile = nilfs_iget_locked(sb, NULL, NILFS_CPFILE_INO);
946 if (unlikely(!cpfile))
947 return -ENOMEM;
948 if (!(cpfile->i_state & I_NEW))
949 goto out;
950
951 err = nilfs_mdt_init(cpfile, NILFS_MDT_GFP, 0);
952 if (err)
953 goto failed;
954
955 nilfs_mdt_set_entry_size(cpfile, cpsize,
956 sizeof(struct nilfs_cpfile_header));
957
958 err = nilfs_read_inode_common(cpfile, raw_inode);
959 if (err)
960 goto failed;
961
962 unlock_new_inode(cpfile);
963 out:
964 *inodep = cpfile;
965 return 0;
966 failed:
967 iget_failed(cpfile);
968 return err;
969}
970