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CommitLineData
29619809
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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 *
4b420ab4 16 * Written by Koji Sato.
29619809
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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>
29619809
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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{
1f5abe7e 38 __u64 tcno = cno + NILFS_MDT(cpfile)->mi_first_entry_offset - 1;
4ad364ca 39
29619809
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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;
4ad364ca 49
29619809
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50 return do_div(tcno, nilfs_cpfile_checkpoints_per_block(cpfile));
51}
52
53a2c3bd
RK
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
29619809
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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
1f5abe7e 100 WARN_ON(le32_to_cpu(cp->cp_checkpoints_count) < n);
29619809
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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
53a2c3bd
RK
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
29619809
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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.
1f5abe7e
RK
220 *
221 * %-EINVAL - invalid checkpoint.
29619809
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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
1f5abe7e
RK
235 if (unlikely(cno < 1 || cno > nilfs_mdt_cno(cpfile) ||
236 (cno < nilfs_mdt_cno(cpfile) && create)))
237 return -EINVAL;
29619809
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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);
5fc7b141 261 mark_buffer_dirty(cp_bh);
29619809 262
7b9c0976 263 kaddr = kmap_atomic(header_bh->b_page);
29619809
KS
264 header = nilfs_cpfile_block_get_header(cpfile, header_bh,
265 kaddr);
266 le64_add_cpu(&header->ch_ncheckpoints, 1);
7b9c0976 267 kunmap_atomic(kaddr);
5fc7b141 268 mark_buffer_dirty(header_bh);
29619809
KS
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;
fe0627e7 331 int ret, ncps, nicps, nss, count, i;
29619809 332
1f5abe7e 333 if (unlikely(start == 0 || start > end)) {
feee880f
RK
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);
1f5abe7e 337 return -EINVAL;
29619809
KS
338 }
339
29619809
KS
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;
fe0627e7 346 nss = 0;
29619809
KS
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)
d9a0a345 353 break;
29619809
KS
354 /* skip hole */
355 ret = 0;
356 continue;
357 }
358
7b9c0976 359 kaddr = kmap_atomic(cp_bh->b_page);
29619809
KS
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) {
fe0627e7
RK
364 if (nilfs_checkpoint_snapshot(cp)) {
365 nss++;
366 } else if (!nilfs_checkpoint_invalid(cp)) {
29619809
KS
367 nilfs_checkpoint_set_invalid(cp);
368 nicps++;
369 }
370 }
371 if (nicps > 0) {
372 tnicps += nicps;
5fc7b141 373 mark_buffer_dirty(cp_bh);
29619809 374 nilfs_mdt_mark_dirty(cpfile);
5ee58148
JS
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 */
7b9c0976 381 kunmap_atomic(kaddr);
5ee58148
JS
382 brelse(cp_bh);
383 ret =
384 nilfs_cpfile_delete_checkpoint_block(
385 cpfile, cno);
386 if (ret == 0)
387 continue;
feee880f
RK
388 nilfs_msg(cpfile->i_sb, KERN_ERR,
389 "error %d deleting checkpoint block",
390 ret);
5ee58148
JS
391 break;
392 }
29619809
KS
393 }
394 }
395
7b9c0976 396 kunmap_atomic(kaddr);
29619809
KS
397 brelse(cp_bh);
398 }
399
400 if (tnicps > 0) {
7b9c0976 401 kaddr = kmap_atomic(header_bh->b_page);
29619809
KS
402 header = nilfs_cpfile_block_get_header(cpfile, header_bh,
403 kaddr);
6c98cd4e 404 le64_add_cpu(&header->ch_ncheckpoints, -(u64)tnicps);
5fc7b141 405 mark_buffer_dirty(header_bh);
29619809 406 nilfs_mdt_mark_dirty(cpfile);
7b9c0976 407 kunmap_atomic(kaddr);
29619809 408 }
62013ab5 409
29619809 410 brelse(header_bh);
fe0627e7
RK
411 if (nss > 0)
412 ret = -EBUSY;
29619809
KS
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
76068c4f 432static ssize_t nilfs_cpfile_do_get_cpinfo(struct inode *cpfile, __u64 *cnop,
0c6c44cb
RK
433 void *buf, unsigned int cisz,
434 size_t nci)
29619809
KS
435{
436 struct nilfs_checkpoint *cp;
003ff182 437 struct nilfs_cpinfo *ci = buf;
29619809
KS
438 struct buffer_head *bh;
439 size_t cpsz = NILFS_MDT(cpfile)->mi_entry_size;
76068c4f 440 __u64 cur_cno = nilfs_mdt_cno(cpfile), cno = *cnop;
29619809
KS
441 void *kaddr;
442 int n, ret;
443 int ncps, i;
444
1f5abe7e
RK
445 if (cno == 0)
446 return -ENOENT; /* checkpoint number 0 is invalid */
29619809
KS
447 down_read(&NILFS_MDT(cpfile)->mi_sem);
448
53a2c3bd
RK
449 for (n = 0; n < nci; cno += ncps) {
450 ret = nilfs_cpfile_find_checkpoint_block(
451 cpfile, cno, cur_cno - 1, &cno, &bh);
29619809 452 if (ret < 0) {
53a2c3bd
RK
453 if (likely(ret == -ENOENT))
454 break;
455 goto out;
29619809 456 }
53a2c3bd 457 ncps = nilfs_cpfile_checkpoints_in_block(cpfile, cno, cur_cno);
29619809 458
7b9c0976 459 kaddr = kmap_atomic(bh->b_page);
29619809
KS
460 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr);
461 for (i = 0; i < ncps && n < nci; i++, cp = (void *)cp + cpsz) {
003ff182
RK
462 if (!nilfs_checkpoint_invalid(cp)) {
463 nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp,
464 ci);
465 ci = (void *)ci + cisz;
466 n++;
467 }
29619809 468 }
7b9c0976 469 kunmap_atomic(kaddr);
29619809
KS
470 brelse(bh);
471 }
472
473 ret = n;
003ff182
RK
474 if (n > 0) {
475 ci = (void *)ci - cisz;
476 *cnop = ci->ci_cno + 1;
477 }
29619809
KS
478
479 out:
480 up_read(&NILFS_MDT(cpfile)->mi_sem);
481 return ret;
482}
483
b028fcfc 484static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 *cnop,
0c6c44cb
RK
485 void *buf, unsigned int cisz,
486 size_t nci)
29619809
KS
487{
488 struct buffer_head *bh;
489 struct nilfs_cpfile_header *header;
490 struct nilfs_checkpoint *cp;
003ff182 491 struct nilfs_cpinfo *ci = buf;
b028fcfc 492 __u64 curr = *cnop, next;
29619809
KS
493 unsigned long curr_blkoff, next_blkoff;
494 void *kaddr;
7fa10d20 495 int n = 0, ret;
29619809
KS
496
497 down_read(&NILFS_MDT(cpfile)->mi_sem);
498
b028fcfc 499 if (curr == 0) {
29619809
KS
500 ret = nilfs_cpfile_get_header_block(cpfile, &bh);
501 if (ret < 0)
502 goto out;
7b9c0976 503 kaddr = kmap_atomic(bh->b_page);
29619809
KS
504 header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr);
505 curr = le64_to_cpu(header->ch_snapshot_list.ssl_next);
7b9c0976 506 kunmap_atomic(kaddr);
29619809
KS
507 brelse(bh);
508 if (curr == 0) {
509 ret = 0;
510 goto out;
511 }
b028fcfc
RK
512 } else if (unlikely(curr == ~(__u64)0)) {
513 ret = 0;
514 goto out;
515 }
516
29619809
KS
517 curr_blkoff = nilfs_cpfile_get_blkoff(cpfile, curr);
518 ret = nilfs_cpfile_get_checkpoint_block(cpfile, curr, 0, &bh);
7fa10d20
RK
519 if (unlikely(ret < 0)) {
520 if (ret == -ENOENT)
521 ret = 0; /* No snapshots (started from a hole block) */
29619809 522 goto out;
7fa10d20 523 }
7b9c0976 524 kaddr = kmap_atomic(bh->b_page);
7fa10d20
RK
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)))
29619809 530 break;
003ff182
RK
531 nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp, ci);
532 ci = (void *)ci + cisz;
533 n++;
7fa10d20
RK
534 next = le64_to_cpu(cp->cp_snapshot_list.ssl_next);
535 if (next == 0)
536 break; /* reach end of the snapshot list */
537
29619809
KS
538 next_blkoff = nilfs_cpfile_get_blkoff(cpfile, next);
539 if (curr_blkoff != next_blkoff) {
7b9c0976 540 kunmap_atomic(kaddr);
29619809
KS
541 brelse(bh);
542 ret = nilfs_cpfile_get_checkpoint_block(cpfile, next,
543 0, &bh);
7fa10d20
RK
544 if (unlikely(ret < 0)) {
545 WARN_ON(ret == -ENOENT);
29619809 546 goto out;
7fa10d20 547 }
7b9c0976 548 kaddr = kmap_atomic(bh->b_page);
29619809
KS
549 }
550 curr = next;
551 curr_blkoff = next_blkoff;
552 }
7b9c0976 553 kunmap_atomic(kaddr);
29619809 554 brelse(bh);
b028fcfc 555 *cnop = curr;
29619809
KS
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 */
b028fcfc
RK
570
571ssize_t nilfs_cpfile_get_cpinfo(struct inode *cpfile, __u64 *cnop, int mode,
0c6c44cb 572 void *buf, unsigned int cisz, size_t nci)
29619809
KS
573{
574 switch (mode) {
575 case NILFS_CHECKPOINT:
003ff182 576 return nilfs_cpfile_do_get_cpinfo(cpfile, cnop, buf, cisz, nci);
29619809 577 case NILFS_SNAPSHOT:
003ff182 578 return nilfs_cpfile_do_get_ssinfo(cpfile, cnop, buf, cisz, nci);
29619809
KS
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;
76068c4f 592 __u64 tcno = cno;
29619809 593 ssize_t nci;
29619809 594
003ff182 595 nci = nilfs_cpfile_do_get_cpinfo(cpfile, &tcno, &ci, sizeof(ci), 1);
29619809
KS
596 if (nci < 0)
597 return nci;
598 else if (nci == 0 || ci.ci_cno != cno)
599 return -ENOENT;
30c25be7
RK
600 else if (nilfs_cpinfo_snapshot(&ci))
601 return -EBUSY;
29619809
KS
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
1f5abe7e
RK
637 if (cno == 0)
638 return -ENOENT; /* checkpoint number 0 is invalid */
29619809
KS
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;
7b9c0976 644 kaddr = kmap_atomic(cp_bh->b_page);
29619809
KS
645 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
646 if (nilfs_checkpoint_invalid(cp)) {
647 ret = -ENOENT;
7b9c0976 648 kunmap_atomic(kaddr);
29619809
KS
649 goto out_cp;
650 }
651 if (nilfs_checkpoint_snapshot(cp)) {
652 ret = 0;
7b9c0976 653 kunmap_atomic(kaddr);
29619809
KS
654 goto out_cp;
655 }
7b9c0976 656 kunmap_atomic(kaddr);
29619809
KS
657
658 ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
659 if (ret < 0)
660 goto out_cp;
7b9c0976 661 kaddr = kmap_atomic(header_bh->b_page);
29619809
KS
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) {
7b9c0976 673 kunmap_atomic(kaddr);
29619809
KS
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;
7b9c0976 679 kaddr = kmap_atomic(curr_bh->b_page);
29619809
KS
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 }
7b9c0976 687 kunmap_atomic(kaddr);
29619809
KS
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
7b9c0976 699 kaddr = kmap_atomic(curr_bh->b_page);
29619809
KS
700 list = nilfs_cpfile_block_get_snapshot_list(
701 cpfile, curr, curr_bh, kaddr);
702 list->ssl_prev = cpu_to_le64(cno);
7b9c0976 703 kunmap_atomic(kaddr);
29619809 704
7b9c0976 705 kaddr = kmap_atomic(cp_bh->b_page);
29619809
KS
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);
7b9c0976 710 kunmap_atomic(kaddr);
29619809 711
7b9c0976 712 kaddr = kmap_atomic(prev_bh->b_page);
29619809
KS
713 list = nilfs_cpfile_block_get_snapshot_list(
714 cpfile, prev, prev_bh, kaddr);
715 list->ssl_next = cpu_to_le64(cno);
7b9c0976 716 kunmap_atomic(kaddr);
29619809 717
7b9c0976 718 kaddr = kmap_atomic(header_bh->b_page);
29619809
KS
719 header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr);
720 le64_add_cpu(&header->ch_nsnapshots, 1);
7b9c0976 721 kunmap_atomic(kaddr);
29619809 722
5fc7b141
RK
723 mark_buffer_dirty(prev_bh);
724 mark_buffer_dirty(curr_bh);
725 mark_buffer_dirty(cp_bh);
726 mark_buffer_dirty(header_bh);
29619809
KS
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
1f5abe7e
RK
755 if (cno == 0)
756 return -ENOENT; /* checkpoint number 0 is invalid */
29619809
KS
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;
7b9c0976 762 kaddr = kmap_atomic(cp_bh->b_page);
29619809
KS
763 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
764 if (nilfs_checkpoint_invalid(cp)) {
765 ret = -ENOENT;
7b9c0976 766 kunmap_atomic(kaddr);
29619809
KS
767 goto out_cp;
768 }
769 if (!nilfs_checkpoint_snapshot(cp)) {
770 ret = 0;
7b9c0976 771 kunmap_atomic(kaddr);
29619809
KS
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);
7b9c0976 778 kunmap_atomic(kaddr);
29619809
KS
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
7b9c0976 802 kaddr = kmap_atomic(next_bh->b_page);
29619809
KS
803 list = nilfs_cpfile_block_get_snapshot_list(
804 cpfile, next, next_bh, kaddr);
805 list->ssl_prev = cpu_to_le64(prev);
7b9c0976 806 kunmap_atomic(kaddr);
29619809 807
7b9c0976 808 kaddr = kmap_atomic(prev_bh->b_page);
29619809
KS
809 list = nilfs_cpfile_block_get_snapshot_list(
810 cpfile, prev, prev_bh, kaddr);
811 list->ssl_next = cpu_to_le64(next);
7b9c0976 812 kunmap_atomic(kaddr);
29619809 813
7b9c0976 814 kaddr = kmap_atomic(cp_bh->b_page);
29619809
KS
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);
7b9c0976 819 kunmap_atomic(kaddr);
29619809 820
7b9c0976 821 kaddr = kmap_atomic(header_bh->b_page);
29619809
KS
822 header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr);
823 le64_add_cpu(&header->ch_nsnapshots, -1);
7b9c0976 824 kunmap_atomic(kaddr);
29619809 825
5fc7b141
RK
826 mark_buffer_dirty(next_bh);
827 mark_buffer_dirty(prev_bh);
828 mark_buffer_dirty(cp_bh);
829 mark_buffer_dirty(header_bh);
29619809
KS
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
076a378b
RK
872 /*
873 * CP number is invalid if it's zero or larger than the
874 * largest existing one.
875 */
43be0ec0
ZY
876 if (cno == 0 || cno >= nilfs_mdt_cno(cpfile))
877 return -ENOENT;
29619809
KS
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;
7b9c0976 883 kaddr = kmap_atomic(bh->b_page);
29619809 884 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr);
43be0ec0
ZY
885 if (nilfs_checkpoint_invalid(cp))
886 ret = -ENOENT;
887 else
888 ret = nilfs_checkpoint_snapshot(cp);
7b9c0976 889 kunmap_atomic(kaddr);
29619809
KS
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{
29619809
KS
917 int ret;
918
29619809
KS
919 switch (mode) {
920 case NILFS_CHECKPOINT:
032dbb3b
RK
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 */
29619809 928 ret = -EBUSY;
032dbb3b 929 else
29619809 930 ret = nilfs_cpfile_clear_snapshot(cpfile, cno);
29619809
KS
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;
7b9c0976 966 kaddr = kmap_atomic(bh->b_page);
29619809
KS
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);
7b9c0976 971 kunmap_atomic(kaddr);
29619809
KS
972 brelse(bh);
973
974 out_sem:
975 up_read(&NILFS_MDT(cpfile)->mi_sem);
976 return ret;
977}
79739565 978
8707df38 979/**
f1e89c86
RK
980 * nilfs_cpfile_read - read or get cpfile inode
981 * @sb: super block instance
79739565 982 * @cpsize: size of a checkpoint entry
f1e89c86
RK
983 * @raw_inode: on-disk cpfile inode
984 * @inodep: buffer to store the inode
79739565 985 */
f1e89c86
RK
986int nilfs_cpfile_read(struct super_block *sb, size_t cpsize,
987 struct nilfs_inode *raw_inode, struct inode **inodep)
79739565
RK
988{
989 struct inode *cpfile;
f1e89c86 990 int err;
79739565 991
0ec060d1 992 if (cpsize > sb->s_blocksize) {
feee880f
RK
993 nilfs_msg(sb, KERN_ERR,
994 "too large checkpoint size: %zu bytes", cpsize);
0ec060d1
RK
995 return -EINVAL;
996 } else if (cpsize < NILFS_MIN_CHECKPOINT_SIZE) {
feee880f
RK
997 nilfs_msg(sb, KERN_ERR,
998 "too small checkpoint size: %zu bytes", cpsize);
0ec060d1
RK
999 return -EINVAL;
1000 }
1001
f1e89c86
RK
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;
79739565 1026}