blob: 8a3d3b65af3f4cee510486f33556ed8bf950d134 [file] [log] [blame]
Koji Sato29619802009-04-06 19:01:31 -07001/*
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 *
Ryusuke Konishi4b420ab2016-05-23 16:23:09 -070016 * Written by Koji Sato.
Koji Sato29619802009-04-06 19:01:31 -070017 */
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 <linux/nilfs2_fs.h>
25#include "mdt.h"
26#include "cpfile.h"
27
28
29static inline unsigned long
30nilfs_cpfile_checkpoints_per_block(const struct inode *cpfile)
31{
32 return NILFS_MDT(cpfile)->mi_entries_per_block;
33}
34
35/* block number from the beginning of the file */
36static unsigned long
37nilfs_cpfile_get_blkoff(const struct inode *cpfile, __u64 cno)
38{
Ryusuke Konishi1f5abe72009-04-06 19:01:55 -070039 __u64 tcno = cno + NILFS_MDT(cpfile)->mi_first_entry_offset - 1;
Ryusuke Konishi4ad364c2016-05-23 16:23:25 -070040
Koji Sato29619802009-04-06 19:01:31 -070041 do_div(tcno, nilfs_cpfile_checkpoints_per_block(cpfile));
42 return (unsigned long)tcno;
43}
44
45/* offset in block */
46static unsigned long
47nilfs_cpfile_get_offset(const struct inode *cpfile, __u64 cno)
48{
49 __u64 tcno = cno + NILFS_MDT(cpfile)->mi_first_entry_offset - 1;
Ryusuke Konishi4ad364c2016-05-23 16:23:25 -070050
Koji Sato29619802009-04-06 19:01:31 -070051 return do_div(tcno, nilfs_cpfile_checkpoints_per_block(cpfile));
52}
53
Ryusuke Konishi53a2c3b2015-04-16 12:46:42 -070054static __u64 nilfs_cpfile_first_checkpoint_in_block(const struct inode *cpfile,
55 unsigned long blkoff)
56{
57 return (__u64)nilfs_cpfile_checkpoints_per_block(cpfile) * blkoff
58 + 1 - NILFS_MDT(cpfile)->mi_first_entry_offset;
59}
60
Koji Sato29619802009-04-06 19:01:31 -070061static unsigned long
62nilfs_cpfile_checkpoints_in_block(const struct inode *cpfile,
63 __u64 curr,
64 __u64 max)
65{
66 return min_t(__u64,
67 nilfs_cpfile_checkpoints_per_block(cpfile) -
68 nilfs_cpfile_get_offset(cpfile, curr),
69 max - curr);
70}
71
72static inline int nilfs_cpfile_is_in_first(const struct inode *cpfile,
73 __u64 cno)
74{
75 return nilfs_cpfile_get_blkoff(cpfile, cno) == 0;
76}
77
78static unsigned int
79nilfs_cpfile_block_add_valid_checkpoints(const struct inode *cpfile,
80 struct buffer_head *bh,
81 void *kaddr,
82 unsigned int n)
83{
84 struct nilfs_checkpoint *cp = kaddr + bh_offset(bh);
85 unsigned int count;
86
87 count = le32_to_cpu(cp->cp_checkpoints_count) + n;
88 cp->cp_checkpoints_count = cpu_to_le32(count);
89 return count;
90}
91
92static unsigned int
93nilfs_cpfile_block_sub_valid_checkpoints(const struct inode *cpfile,
94 struct buffer_head *bh,
95 void *kaddr,
96 unsigned int n)
97{
98 struct nilfs_checkpoint *cp = kaddr + bh_offset(bh);
99 unsigned int count;
100
Ryusuke Konishi1f5abe72009-04-06 19:01:55 -0700101 WARN_ON(le32_to_cpu(cp->cp_checkpoints_count) < n);
Koji Sato29619802009-04-06 19:01:31 -0700102 count = le32_to_cpu(cp->cp_checkpoints_count) - n;
103 cp->cp_checkpoints_count = cpu_to_le32(count);
104 return count;
105}
106
107static inline struct nilfs_cpfile_header *
108nilfs_cpfile_block_get_header(const struct inode *cpfile,
109 struct buffer_head *bh,
110 void *kaddr)
111{
112 return kaddr + bh_offset(bh);
113}
114
115static struct nilfs_checkpoint *
116nilfs_cpfile_block_get_checkpoint(const struct inode *cpfile, __u64 cno,
117 struct buffer_head *bh,
118 void *kaddr)
119{
120 return kaddr + bh_offset(bh) + nilfs_cpfile_get_offset(cpfile, cno) *
121 NILFS_MDT(cpfile)->mi_entry_size;
122}
123
124static void nilfs_cpfile_block_init(struct inode *cpfile,
125 struct buffer_head *bh,
126 void *kaddr)
127{
128 struct nilfs_checkpoint *cp = kaddr + bh_offset(bh);
129 size_t cpsz = NILFS_MDT(cpfile)->mi_entry_size;
130 int n = nilfs_cpfile_checkpoints_per_block(cpfile);
131
132 while (n-- > 0) {
133 nilfs_checkpoint_set_invalid(cp);
134 cp = (void *)cp + cpsz;
135 }
136}
137
138static inline int nilfs_cpfile_get_header_block(struct inode *cpfile,
139 struct buffer_head **bhp)
140{
141 return nilfs_mdt_get_block(cpfile, 0, 0, NULL, bhp);
142}
143
144static inline int nilfs_cpfile_get_checkpoint_block(struct inode *cpfile,
145 __u64 cno,
146 int create,
147 struct buffer_head **bhp)
148{
149 return nilfs_mdt_get_block(cpfile,
150 nilfs_cpfile_get_blkoff(cpfile, cno),
151 create, nilfs_cpfile_block_init, bhp);
152}
153
Ryusuke Konishi53a2c3b2015-04-16 12:46:42 -0700154/**
155 * nilfs_cpfile_find_checkpoint_block - find and get a buffer on cpfile
156 * @cpfile: inode of cpfile
157 * @start_cno: start checkpoint number (inclusive)
158 * @end_cno: end checkpoint number (inclusive)
159 * @cnop: place to store the next checkpoint number
160 * @bhp: place to store a pointer to buffer_head struct
161 *
162 * Return Value: On success, it returns 0. On error, the following negative
163 * error code is returned.
164 *
165 * %-ENOMEM - Insufficient memory available.
166 *
167 * %-EIO - I/O error
168 *
169 * %-ENOENT - no block exists in the range.
170 */
171static int nilfs_cpfile_find_checkpoint_block(struct inode *cpfile,
172 __u64 start_cno, __u64 end_cno,
173 __u64 *cnop,
174 struct buffer_head **bhp)
175{
176 unsigned long start, end, blkoff;
177 int ret;
178
179 if (unlikely(start_cno > end_cno))
180 return -ENOENT;
181
182 start = nilfs_cpfile_get_blkoff(cpfile, start_cno);
183 end = nilfs_cpfile_get_blkoff(cpfile, end_cno);
184
185 ret = nilfs_mdt_find_block(cpfile, start, end, &blkoff, bhp);
186 if (!ret)
187 *cnop = (blkoff == start) ? start_cno :
188 nilfs_cpfile_first_checkpoint_in_block(cpfile, blkoff);
189 return ret;
190}
191
Koji Sato29619802009-04-06 19:01:31 -0700192static inline int nilfs_cpfile_delete_checkpoint_block(struct inode *cpfile,
193 __u64 cno)
194{
195 return nilfs_mdt_delete_block(cpfile,
196 nilfs_cpfile_get_blkoff(cpfile, cno));
197}
198
199/**
200 * nilfs_cpfile_get_checkpoint - get a checkpoint
201 * @cpfile: inode of checkpoint file
202 * @cno: checkpoint number
203 * @create: create flag
204 * @cpp: pointer to a checkpoint
205 * @bhp: pointer to a buffer head
206 *
207 * Description: nilfs_cpfile_get_checkpoint() acquires the checkpoint
208 * specified by @cno. A new checkpoint will be created if @cno is the current
209 * checkpoint number and @create is nonzero.
210 *
211 * Return Value: On success, 0 is returned, and the checkpoint and the
212 * buffer head of the buffer on which the checkpoint is located are stored in
213 * the place pointed by @cpp and @bhp, respectively. On error, one of the
214 * following negative error codes is returned.
215 *
216 * %-EIO - I/O error.
217 *
218 * %-ENOMEM - Insufficient amount of memory available.
219 *
220 * %-ENOENT - No such checkpoint.
Ryusuke Konishi1f5abe72009-04-06 19:01:55 -0700221 *
222 * %-EINVAL - invalid checkpoint.
Koji Sato29619802009-04-06 19:01:31 -0700223 */
224int nilfs_cpfile_get_checkpoint(struct inode *cpfile,
225 __u64 cno,
226 int create,
227 struct nilfs_checkpoint **cpp,
228 struct buffer_head **bhp)
229{
230 struct buffer_head *header_bh, *cp_bh;
231 struct nilfs_cpfile_header *header;
232 struct nilfs_checkpoint *cp;
233 void *kaddr;
234 int ret;
235
Ryusuke Konishi1f5abe72009-04-06 19:01:55 -0700236 if (unlikely(cno < 1 || cno > nilfs_mdt_cno(cpfile) ||
237 (cno < nilfs_mdt_cno(cpfile) && create)))
238 return -EINVAL;
Koji Sato29619802009-04-06 19:01:31 -0700239
240 down_write(&NILFS_MDT(cpfile)->mi_sem);
241
242 ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
243 if (ret < 0)
244 goto out_sem;
245 ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, create, &cp_bh);
246 if (ret < 0)
247 goto out_header;
248 kaddr = kmap(cp_bh->b_page);
249 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
250 if (nilfs_checkpoint_invalid(cp)) {
251 if (!create) {
252 kunmap(cp_bh->b_page);
253 brelse(cp_bh);
254 ret = -ENOENT;
255 goto out_header;
256 }
257 /* a newly-created checkpoint */
258 nilfs_checkpoint_clear_invalid(cp);
259 if (!nilfs_cpfile_is_in_first(cpfile, cno))
260 nilfs_cpfile_block_add_valid_checkpoints(cpfile, cp_bh,
261 kaddr, 1);
Ryusuke Konishi5fc7b142011-05-05 12:56:51 +0900262 mark_buffer_dirty(cp_bh);
Koji Sato29619802009-04-06 19:01:31 -0700263
Cong Wang7b9c0972011-11-25 23:14:33 +0800264 kaddr = kmap_atomic(header_bh->b_page);
Koji Sato29619802009-04-06 19:01:31 -0700265 header = nilfs_cpfile_block_get_header(cpfile, header_bh,
266 kaddr);
267 le64_add_cpu(&header->ch_ncheckpoints, 1);
Cong Wang7b9c0972011-11-25 23:14:33 +0800268 kunmap_atomic(kaddr);
Ryusuke Konishi5fc7b142011-05-05 12:56:51 +0900269 mark_buffer_dirty(header_bh);
Koji Sato29619802009-04-06 19:01:31 -0700270 nilfs_mdt_mark_dirty(cpfile);
271 }
272
273 if (cpp != NULL)
274 *cpp = cp;
275 *bhp = cp_bh;
276
277 out_header:
278 brelse(header_bh);
279
280 out_sem:
281 up_write(&NILFS_MDT(cpfile)->mi_sem);
282 return ret;
283}
284
285/**
286 * nilfs_cpfile_put_checkpoint - put a checkpoint
287 * @cpfile: inode of checkpoint file
288 * @cno: checkpoint number
289 * @bh: buffer head
290 *
291 * Description: nilfs_cpfile_put_checkpoint() releases the checkpoint
292 * specified by @cno. @bh must be the buffer head which has been returned by
293 * a previous call to nilfs_cpfile_get_checkpoint() with @cno.
294 */
295void nilfs_cpfile_put_checkpoint(struct inode *cpfile, __u64 cno,
296 struct buffer_head *bh)
297{
298 kunmap(bh->b_page);
299 brelse(bh);
300}
301
302/**
303 * nilfs_cpfile_delete_checkpoints - delete checkpoints
304 * @cpfile: inode of checkpoint file
305 * @start: start checkpoint number
306 * @end: end checkpoint numer
307 *
308 * Description: nilfs_cpfile_delete_checkpoints() deletes the checkpoints in
309 * the period from @start to @end, excluding @end itself. The checkpoints
310 * which have been already deleted are ignored.
311 *
312 * Return Value: On success, 0 is returned. On error, one of the following
313 * negative error codes is returned.
314 *
315 * %-EIO - I/O error.
316 *
317 * %-ENOMEM - Insufficient amount of memory available.
318 *
319 * %-EINVAL - invalid checkpoints.
320 */
321int nilfs_cpfile_delete_checkpoints(struct inode *cpfile,
322 __u64 start,
323 __u64 end)
324{
325 struct buffer_head *header_bh, *cp_bh;
326 struct nilfs_cpfile_header *header;
327 struct nilfs_checkpoint *cp;
328 size_t cpsz = NILFS_MDT(cpfile)->mi_entry_size;
329 __u64 cno;
330 void *kaddr;
331 unsigned long tnicps;
Ryusuke Konishife0627e2012-07-30 14:42:05 -0700332 int ret, ncps, nicps, nss, count, i;
Koji Sato29619802009-04-06 19:01:31 -0700333
Ryusuke Konishi1f5abe72009-04-06 19:01:55 -0700334 if (unlikely(start == 0 || start > end)) {
335 printk(KERN_ERR "%s: invalid range of checkpoint numbers: "
336 "[%llu, %llu)\n", __func__,
337 (unsigned long long)start, (unsigned long long)end);
338 return -EINVAL;
Koji Sato29619802009-04-06 19:01:31 -0700339 }
340
Koji Sato29619802009-04-06 19:01:31 -0700341 down_write(&NILFS_MDT(cpfile)->mi_sem);
342
343 ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
344 if (ret < 0)
345 goto out_sem;
346 tnicps = 0;
Ryusuke Konishife0627e2012-07-30 14:42:05 -0700347 nss = 0;
Koji Sato29619802009-04-06 19:01:31 -0700348
349 for (cno = start; cno < end; cno += ncps) {
350 ncps = nilfs_cpfile_checkpoints_in_block(cpfile, cno, end);
351 ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh);
352 if (ret < 0) {
353 if (ret != -ENOENT)
Jiro SEKIBAd9a0a342009-07-04 23:00:53 +0900354 break;
Koji Sato29619802009-04-06 19:01:31 -0700355 /* skip hole */
356 ret = 0;
357 continue;
358 }
359
Cong Wang7b9c0972011-11-25 23:14:33 +0800360 kaddr = kmap_atomic(cp_bh->b_page);
Koji Sato29619802009-04-06 19:01:31 -0700361 cp = nilfs_cpfile_block_get_checkpoint(
362 cpfile, cno, cp_bh, kaddr);
363 nicps = 0;
364 for (i = 0; i < ncps; i++, cp = (void *)cp + cpsz) {
Ryusuke Konishife0627e2012-07-30 14:42:05 -0700365 if (nilfs_checkpoint_snapshot(cp)) {
366 nss++;
367 } else if (!nilfs_checkpoint_invalid(cp)) {
Koji Sato29619802009-04-06 19:01:31 -0700368 nilfs_checkpoint_set_invalid(cp);
369 nicps++;
370 }
371 }
372 if (nicps > 0) {
373 tnicps += nicps;
Ryusuke Konishi5fc7b142011-05-05 12:56:51 +0900374 mark_buffer_dirty(cp_bh);
Koji Sato29619802009-04-06 19:01:31 -0700375 nilfs_mdt_mark_dirty(cpfile);
Jiro SEKIBA5ee58142009-12-06 15:43:56 +0900376 if (!nilfs_cpfile_is_in_first(cpfile, cno)) {
377 count =
378 nilfs_cpfile_block_sub_valid_checkpoints(
379 cpfile, cp_bh, kaddr, nicps);
380 if (count == 0) {
381 /* make hole */
Cong Wang7b9c0972011-11-25 23:14:33 +0800382 kunmap_atomic(kaddr);
Jiro SEKIBA5ee58142009-12-06 15:43:56 +0900383 brelse(cp_bh);
384 ret =
385 nilfs_cpfile_delete_checkpoint_block(
386 cpfile, cno);
387 if (ret == 0)
388 continue;
389 printk(KERN_ERR
390 "%s: cannot delete block\n",
391 __func__);
392 break;
393 }
Koji Sato29619802009-04-06 19:01:31 -0700394 }
395 }
396
Cong Wang7b9c0972011-11-25 23:14:33 +0800397 kunmap_atomic(kaddr);
Koji Sato29619802009-04-06 19:01:31 -0700398 brelse(cp_bh);
399 }
400
401 if (tnicps > 0) {
Cong Wang7b9c0972011-11-25 23:14:33 +0800402 kaddr = kmap_atomic(header_bh->b_page);
Koji Sato29619802009-04-06 19:01:31 -0700403 header = nilfs_cpfile_block_get_header(cpfile, header_bh,
404 kaddr);
Koji Sato6c98cd42009-04-06 19:01:32 -0700405 le64_add_cpu(&header->ch_ncheckpoints, -(u64)tnicps);
Ryusuke Konishi5fc7b142011-05-05 12:56:51 +0900406 mark_buffer_dirty(header_bh);
Koji Sato29619802009-04-06 19:01:31 -0700407 nilfs_mdt_mark_dirty(cpfile);
Cong Wang7b9c0972011-11-25 23:14:33 +0800408 kunmap_atomic(kaddr);
Koji Sato29619802009-04-06 19:01:31 -0700409 }
Ryusuke Konishi62013ab2009-05-30 21:50:58 +0900410
Koji Sato29619802009-04-06 19:01:31 -0700411 brelse(header_bh);
Ryusuke Konishife0627e2012-07-30 14:42:05 -0700412 if (nss > 0)
413 ret = -EBUSY;
Koji Sato29619802009-04-06 19:01:31 -0700414
415 out_sem:
416 up_write(&NILFS_MDT(cpfile)->mi_sem);
417 return ret;
418}
419
420static void nilfs_cpfile_checkpoint_to_cpinfo(struct inode *cpfile,
421 struct nilfs_checkpoint *cp,
422 struct nilfs_cpinfo *ci)
423{
424 ci->ci_flags = le32_to_cpu(cp->cp_flags);
425 ci->ci_cno = le64_to_cpu(cp->cp_cno);
426 ci->ci_create = le64_to_cpu(cp->cp_create);
427 ci->ci_nblk_inc = le64_to_cpu(cp->cp_nblk_inc);
428 ci->ci_inodes_count = le64_to_cpu(cp->cp_inodes_count);
429 ci->ci_blocks_count = le64_to_cpu(cp->cp_blocks_count);
430 ci->ci_next = le64_to_cpu(cp->cp_snapshot_list.ssl_next);
431}
432
Ryusuke Konishi76068c42009-04-06 19:01:50 -0700433static ssize_t nilfs_cpfile_do_get_cpinfo(struct inode *cpfile, __u64 *cnop,
Ryusuke Konishi0c6c44c2016-05-23 16:23:39 -0700434 void *buf, unsigned int cisz,
435 size_t nci)
Koji Sato29619802009-04-06 19:01:31 -0700436{
437 struct nilfs_checkpoint *cp;
Ryusuke Konishi003ff182009-05-12 03:58:47 +0900438 struct nilfs_cpinfo *ci = buf;
Koji Sato29619802009-04-06 19:01:31 -0700439 struct buffer_head *bh;
440 size_t cpsz = NILFS_MDT(cpfile)->mi_entry_size;
Ryusuke Konishi76068c42009-04-06 19:01:50 -0700441 __u64 cur_cno = nilfs_mdt_cno(cpfile), cno = *cnop;
Koji Sato29619802009-04-06 19:01:31 -0700442 void *kaddr;
443 int n, ret;
444 int ncps, i;
445
Ryusuke Konishi1f5abe72009-04-06 19:01:55 -0700446 if (cno == 0)
447 return -ENOENT; /* checkpoint number 0 is invalid */
Koji Sato29619802009-04-06 19:01:31 -0700448 down_read(&NILFS_MDT(cpfile)->mi_sem);
449
Ryusuke Konishi53a2c3b2015-04-16 12:46:42 -0700450 for (n = 0; n < nci; cno += ncps) {
451 ret = nilfs_cpfile_find_checkpoint_block(
452 cpfile, cno, cur_cno - 1, &cno, &bh);
Koji Sato29619802009-04-06 19:01:31 -0700453 if (ret < 0) {
Ryusuke Konishi53a2c3b2015-04-16 12:46:42 -0700454 if (likely(ret == -ENOENT))
455 break;
456 goto out;
Koji Sato29619802009-04-06 19:01:31 -0700457 }
Ryusuke Konishi53a2c3b2015-04-16 12:46:42 -0700458 ncps = nilfs_cpfile_checkpoints_in_block(cpfile, cno, cur_cno);
Koji Sato29619802009-04-06 19:01:31 -0700459
Cong Wang7b9c0972011-11-25 23:14:33 +0800460 kaddr = kmap_atomic(bh->b_page);
Koji Sato29619802009-04-06 19:01:31 -0700461 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr);
462 for (i = 0; i < ncps && n < nci; i++, cp = (void *)cp + cpsz) {
Ryusuke Konishi003ff182009-05-12 03:58:47 +0900463 if (!nilfs_checkpoint_invalid(cp)) {
464 nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp,
465 ci);
466 ci = (void *)ci + cisz;
467 n++;
468 }
Koji Sato29619802009-04-06 19:01:31 -0700469 }
Cong Wang7b9c0972011-11-25 23:14:33 +0800470 kunmap_atomic(kaddr);
Koji Sato29619802009-04-06 19:01:31 -0700471 brelse(bh);
472 }
473
474 ret = n;
Ryusuke Konishi003ff182009-05-12 03:58:47 +0900475 if (n > 0) {
476 ci = (void *)ci - cisz;
477 *cnop = ci->ci_cno + 1;
478 }
Koji Sato29619802009-04-06 19:01:31 -0700479
480 out:
481 up_read(&NILFS_MDT(cpfile)->mi_sem);
482 return ret;
483}
484
Ryusuke Konishib028fcf2009-04-06 19:01:47 -0700485static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 *cnop,
Ryusuke Konishi0c6c44c2016-05-23 16:23:39 -0700486 void *buf, unsigned int cisz,
487 size_t nci)
Koji Sato29619802009-04-06 19:01:31 -0700488{
489 struct buffer_head *bh;
490 struct nilfs_cpfile_header *header;
491 struct nilfs_checkpoint *cp;
Ryusuke Konishi003ff182009-05-12 03:58:47 +0900492 struct nilfs_cpinfo *ci = buf;
Ryusuke Konishib028fcf2009-04-06 19:01:47 -0700493 __u64 curr = *cnop, next;
Koji Sato29619802009-04-06 19:01:31 -0700494 unsigned long curr_blkoff, next_blkoff;
495 void *kaddr;
Ryusuke Konishi7fa10d22009-04-06 19:01:48 -0700496 int n = 0, ret;
Koji Sato29619802009-04-06 19:01:31 -0700497
498 down_read(&NILFS_MDT(cpfile)->mi_sem);
499
Ryusuke Konishib028fcf2009-04-06 19:01:47 -0700500 if (curr == 0) {
Koji Sato29619802009-04-06 19:01:31 -0700501 ret = nilfs_cpfile_get_header_block(cpfile, &bh);
502 if (ret < 0)
503 goto out;
Cong Wang7b9c0972011-11-25 23:14:33 +0800504 kaddr = kmap_atomic(bh->b_page);
Koji Sato29619802009-04-06 19:01:31 -0700505 header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr);
506 curr = le64_to_cpu(header->ch_snapshot_list.ssl_next);
Cong Wang7b9c0972011-11-25 23:14:33 +0800507 kunmap_atomic(kaddr);
Koji Sato29619802009-04-06 19:01:31 -0700508 brelse(bh);
509 if (curr == 0) {
510 ret = 0;
511 goto out;
512 }
Ryusuke Konishib028fcf2009-04-06 19:01:47 -0700513 } else if (unlikely(curr == ~(__u64)0)) {
514 ret = 0;
515 goto out;
516 }
517
Koji Sato29619802009-04-06 19:01:31 -0700518 curr_blkoff = nilfs_cpfile_get_blkoff(cpfile, curr);
519 ret = nilfs_cpfile_get_checkpoint_block(cpfile, curr, 0, &bh);
Ryusuke Konishi7fa10d22009-04-06 19:01:48 -0700520 if (unlikely(ret < 0)) {
521 if (ret == -ENOENT)
522 ret = 0; /* No snapshots (started from a hole block) */
Koji Sato29619802009-04-06 19:01:31 -0700523 goto out;
Ryusuke Konishi7fa10d22009-04-06 19:01:48 -0700524 }
Cong Wang7b9c0972011-11-25 23:14:33 +0800525 kaddr = kmap_atomic(bh->b_page);
Ryusuke Konishi7fa10d22009-04-06 19:01:48 -0700526 while (n < nci) {
527 cp = nilfs_cpfile_block_get_checkpoint(cpfile, curr, bh, kaddr);
528 curr = ~(__u64)0; /* Terminator */
529 if (unlikely(nilfs_checkpoint_invalid(cp) ||
530 !nilfs_checkpoint_snapshot(cp)))
Koji Sato29619802009-04-06 19:01:31 -0700531 break;
Ryusuke Konishi003ff182009-05-12 03:58:47 +0900532 nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp, ci);
533 ci = (void *)ci + cisz;
534 n++;
Ryusuke Konishi7fa10d22009-04-06 19:01:48 -0700535 next = le64_to_cpu(cp->cp_snapshot_list.ssl_next);
536 if (next == 0)
537 break; /* reach end of the snapshot list */
538
Koji Sato29619802009-04-06 19:01:31 -0700539 next_blkoff = nilfs_cpfile_get_blkoff(cpfile, next);
540 if (curr_blkoff != next_blkoff) {
Cong Wang7b9c0972011-11-25 23:14:33 +0800541 kunmap_atomic(kaddr);
Koji Sato29619802009-04-06 19:01:31 -0700542 brelse(bh);
543 ret = nilfs_cpfile_get_checkpoint_block(cpfile, next,
544 0, &bh);
Ryusuke Konishi7fa10d22009-04-06 19:01:48 -0700545 if (unlikely(ret < 0)) {
546 WARN_ON(ret == -ENOENT);
Koji Sato29619802009-04-06 19:01:31 -0700547 goto out;
Ryusuke Konishi7fa10d22009-04-06 19:01:48 -0700548 }
Cong Wang7b9c0972011-11-25 23:14:33 +0800549 kaddr = kmap_atomic(bh->b_page);
Koji Sato29619802009-04-06 19:01:31 -0700550 }
551 curr = next;
552 curr_blkoff = next_blkoff;
553 }
Cong Wang7b9c0972011-11-25 23:14:33 +0800554 kunmap_atomic(kaddr);
Koji Sato29619802009-04-06 19:01:31 -0700555 brelse(bh);
Ryusuke Konishib028fcf2009-04-06 19:01:47 -0700556 *cnop = curr;
Koji Sato29619802009-04-06 19:01:31 -0700557 ret = n;
558
559 out:
560 up_read(&NILFS_MDT(cpfile)->mi_sem);
561 return ret;
562}
563
564/**
565 * nilfs_cpfile_get_cpinfo -
566 * @cpfile:
567 * @cno:
568 * @ci:
569 * @nci:
570 */
Ryusuke Konishib028fcf2009-04-06 19:01:47 -0700571
572ssize_t nilfs_cpfile_get_cpinfo(struct inode *cpfile, __u64 *cnop, int mode,
Ryusuke Konishi0c6c44c2016-05-23 16:23:39 -0700573 void *buf, unsigned int cisz, size_t nci)
Koji Sato29619802009-04-06 19:01:31 -0700574{
575 switch (mode) {
576 case NILFS_CHECKPOINT:
Ryusuke Konishi003ff182009-05-12 03:58:47 +0900577 return nilfs_cpfile_do_get_cpinfo(cpfile, cnop, buf, cisz, nci);
Koji Sato29619802009-04-06 19:01:31 -0700578 case NILFS_SNAPSHOT:
Ryusuke Konishi003ff182009-05-12 03:58:47 +0900579 return nilfs_cpfile_do_get_ssinfo(cpfile, cnop, buf, cisz, nci);
Koji Sato29619802009-04-06 19:01:31 -0700580 default:
581 return -EINVAL;
582 }
583}
584
585/**
586 * nilfs_cpfile_delete_checkpoint -
587 * @cpfile:
588 * @cno:
589 */
590int nilfs_cpfile_delete_checkpoint(struct inode *cpfile, __u64 cno)
591{
592 struct nilfs_cpinfo ci;
Ryusuke Konishi76068c42009-04-06 19:01:50 -0700593 __u64 tcno = cno;
Koji Sato29619802009-04-06 19:01:31 -0700594 ssize_t nci;
Koji Sato29619802009-04-06 19:01:31 -0700595
Ryusuke Konishi003ff182009-05-12 03:58:47 +0900596 nci = nilfs_cpfile_do_get_cpinfo(cpfile, &tcno, &ci, sizeof(ci), 1);
Koji Sato29619802009-04-06 19:01:31 -0700597 if (nci < 0)
598 return nci;
599 else if (nci == 0 || ci.ci_cno != cno)
600 return -ENOENT;
Ryusuke Konishi30c25be2009-05-30 19:08:09 +0900601 else if (nilfs_cpinfo_snapshot(&ci))
602 return -EBUSY;
Koji Sato29619802009-04-06 19:01:31 -0700603
604 return nilfs_cpfile_delete_checkpoints(cpfile, cno, cno + 1);
605}
606
607static struct nilfs_snapshot_list *
608nilfs_cpfile_block_get_snapshot_list(const struct inode *cpfile,
609 __u64 cno,
610 struct buffer_head *bh,
611 void *kaddr)
612{
613 struct nilfs_cpfile_header *header;
614 struct nilfs_checkpoint *cp;
615 struct nilfs_snapshot_list *list;
616
617 if (cno != 0) {
618 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr);
619 list = &cp->cp_snapshot_list;
620 } else {
621 header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr);
622 list = &header->ch_snapshot_list;
623 }
624 return list;
625}
626
627static int nilfs_cpfile_set_snapshot(struct inode *cpfile, __u64 cno)
628{
629 struct buffer_head *header_bh, *curr_bh, *prev_bh, *cp_bh;
630 struct nilfs_cpfile_header *header;
631 struct nilfs_checkpoint *cp;
632 struct nilfs_snapshot_list *list;
633 __u64 curr, prev;
634 unsigned long curr_blkoff, prev_blkoff;
635 void *kaddr;
636 int ret;
637
Ryusuke Konishi1f5abe72009-04-06 19:01:55 -0700638 if (cno == 0)
639 return -ENOENT; /* checkpoint number 0 is invalid */
Koji Sato29619802009-04-06 19:01:31 -0700640 down_write(&NILFS_MDT(cpfile)->mi_sem);
641
642 ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh);
643 if (ret < 0)
644 goto out_sem;
Cong Wang7b9c0972011-11-25 23:14:33 +0800645 kaddr = kmap_atomic(cp_bh->b_page);
Koji Sato29619802009-04-06 19:01:31 -0700646 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
647 if (nilfs_checkpoint_invalid(cp)) {
648 ret = -ENOENT;
Cong Wang7b9c0972011-11-25 23:14:33 +0800649 kunmap_atomic(kaddr);
Koji Sato29619802009-04-06 19:01:31 -0700650 goto out_cp;
651 }
652 if (nilfs_checkpoint_snapshot(cp)) {
653 ret = 0;
Cong Wang7b9c0972011-11-25 23:14:33 +0800654 kunmap_atomic(kaddr);
Koji Sato29619802009-04-06 19:01:31 -0700655 goto out_cp;
656 }
Cong Wang7b9c0972011-11-25 23:14:33 +0800657 kunmap_atomic(kaddr);
Koji Sato29619802009-04-06 19:01:31 -0700658
659 ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
660 if (ret < 0)
661 goto out_cp;
Cong Wang7b9c0972011-11-25 23:14:33 +0800662 kaddr = kmap_atomic(header_bh->b_page);
Koji Sato29619802009-04-06 19:01:31 -0700663 header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr);
664 list = &header->ch_snapshot_list;
665 curr_bh = header_bh;
666 get_bh(curr_bh);
667 curr = 0;
668 curr_blkoff = 0;
669 prev = le64_to_cpu(list->ssl_prev);
670 while (prev > cno) {
671 prev_blkoff = nilfs_cpfile_get_blkoff(cpfile, prev);
672 curr = prev;
673 if (curr_blkoff != prev_blkoff) {
Cong Wang7b9c0972011-11-25 23:14:33 +0800674 kunmap_atomic(kaddr);
Koji Sato29619802009-04-06 19:01:31 -0700675 brelse(curr_bh);
676 ret = nilfs_cpfile_get_checkpoint_block(cpfile, curr,
677 0, &curr_bh);
678 if (ret < 0)
679 goto out_header;
Cong Wang7b9c0972011-11-25 23:14:33 +0800680 kaddr = kmap_atomic(curr_bh->b_page);
Koji Sato29619802009-04-06 19:01:31 -0700681 }
682 curr_blkoff = prev_blkoff;
683 cp = nilfs_cpfile_block_get_checkpoint(
684 cpfile, curr, curr_bh, kaddr);
685 list = &cp->cp_snapshot_list;
686 prev = le64_to_cpu(list->ssl_prev);
687 }
Cong Wang7b9c0972011-11-25 23:14:33 +0800688 kunmap_atomic(kaddr);
Koji Sato29619802009-04-06 19:01:31 -0700689
690 if (prev != 0) {
691 ret = nilfs_cpfile_get_checkpoint_block(cpfile, prev, 0,
692 &prev_bh);
693 if (ret < 0)
694 goto out_curr;
695 } else {
696 prev_bh = header_bh;
697 get_bh(prev_bh);
698 }
699
Cong Wang7b9c0972011-11-25 23:14:33 +0800700 kaddr = kmap_atomic(curr_bh->b_page);
Koji Sato29619802009-04-06 19:01:31 -0700701 list = nilfs_cpfile_block_get_snapshot_list(
702 cpfile, curr, curr_bh, kaddr);
703 list->ssl_prev = cpu_to_le64(cno);
Cong Wang7b9c0972011-11-25 23:14:33 +0800704 kunmap_atomic(kaddr);
Koji Sato29619802009-04-06 19:01:31 -0700705
Cong Wang7b9c0972011-11-25 23:14:33 +0800706 kaddr = kmap_atomic(cp_bh->b_page);
Koji Sato29619802009-04-06 19:01:31 -0700707 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
708 cp->cp_snapshot_list.ssl_next = cpu_to_le64(curr);
709 cp->cp_snapshot_list.ssl_prev = cpu_to_le64(prev);
710 nilfs_checkpoint_set_snapshot(cp);
Cong Wang7b9c0972011-11-25 23:14:33 +0800711 kunmap_atomic(kaddr);
Koji Sato29619802009-04-06 19:01:31 -0700712
Cong Wang7b9c0972011-11-25 23:14:33 +0800713 kaddr = kmap_atomic(prev_bh->b_page);
Koji Sato29619802009-04-06 19:01:31 -0700714 list = nilfs_cpfile_block_get_snapshot_list(
715 cpfile, prev, prev_bh, kaddr);
716 list->ssl_next = cpu_to_le64(cno);
Cong Wang7b9c0972011-11-25 23:14:33 +0800717 kunmap_atomic(kaddr);
Koji Sato29619802009-04-06 19:01:31 -0700718
Cong Wang7b9c0972011-11-25 23:14:33 +0800719 kaddr = kmap_atomic(header_bh->b_page);
Koji Sato29619802009-04-06 19:01:31 -0700720 header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr);
721 le64_add_cpu(&header->ch_nsnapshots, 1);
Cong Wang7b9c0972011-11-25 23:14:33 +0800722 kunmap_atomic(kaddr);
Koji Sato29619802009-04-06 19:01:31 -0700723
Ryusuke Konishi5fc7b142011-05-05 12:56:51 +0900724 mark_buffer_dirty(prev_bh);
725 mark_buffer_dirty(curr_bh);
726 mark_buffer_dirty(cp_bh);
727 mark_buffer_dirty(header_bh);
Koji Sato29619802009-04-06 19:01:31 -0700728 nilfs_mdt_mark_dirty(cpfile);
729
730 brelse(prev_bh);
731
732 out_curr:
733 brelse(curr_bh);
734
735 out_header:
736 brelse(header_bh);
737
738 out_cp:
739 brelse(cp_bh);
740
741 out_sem:
742 up_write(&NILFS_MDT(cpfile)->mi_sem);
743 return ret;
744}
745
746static int nilfs_cpfile_clear_snapshot(struct inode *cpfile, __u64 cno)
747{
748 struct buffer_head *header_bh, *next_bh, *prev_bh, *cp_bh;
749 struct nilfs_cpfile_header *header;
750 struct nilfs_checkpoint *cp;
751 struct nilfs_snapshot_list *list;
752 __u64 next, prev;
753 void *kaddr;
754 int ret;
755
Ryusuke Konishi1f5abe72009-04-06 19:01:55 -0700756 if (cno == 0)
757 return -ENOENT; /* checkpoint number 0 is invalid */
Koji Sato29619802009-04-06 19:01:31 -0700758 down_write(&NILFS_MDT(cpfile)->mi_sem);
759
760 ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh);
761 if (ret < 0)
762 goto out_sem;
Cong Wang7b9c0972011-11-25 23:14:33 +0800763 kaddr = kmap_atomic(cp_bh->b_page);
Koji Sato29619802009-04-06 19:01:31 -0700764 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
765 if (nilfs_checkpoint_invalid(cp)) {
766 ret = -ENOENT;
Cong Wang7b9c0972011-11-25 23:14:33 +0800767 kunmap_atomic(kaddr);
Koji Sato29619802009-04-06 19:01:31 -0700768 goto out_cp;
769 }
770 if (!nilfs_checkpoint_snapshot(cp)) {
771 ret = 0;
Cong Wang7b9c0972011-11-25 23:14:33 +0800772 kunmap_atomic(kaddr);
Koji Sato29619802009-04-06 19:01:31 -0700773 goto out_cp;
774 }
775
776 list = &cp->cp_snapshot_list;
777 next = le64_to_cpu(list->ssl_next);
778 prev = le64_to_cpu(list->ssl_prev);
Cong Wang7b9c0972011-11-25 23:14:33 +0800779 kunmap_atomic(kaddr);
Koji Sato29619802009-04-06 19:01:31 -0700780
781 ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
782 if (ret < 0)
783 goto out_cp;
784 if (next != 0) {
785 ret = nilfs_cpfile_get_checkpoint_block(cpfile, next, 0,
786 &next_bh);
787 if (ret < 0)
788 goto out_header;
789 } else {
790 next_bh = header_bh;
791 get_bh(next_bh);
792 }
793 if (prev != 0) {
794 ret = nilfs_cpfile_get_checkpoint_block(cpfile, prev, 0,
795 &prev_bh);
796 if (ret < 0)
797 goto out_next;
798 } else {
799 prev_bh = header_bh;
800 get_bh(prev_bh);
801 }
802
Cong Wang7b9c0972011-11-25 23:14:33 +0800803 kaddr = kmap_atomic(next_bh->b_page);
Koji Sato29619802009-04-06 19:01:31 -0700804 list = nilfs_cpfile_block_get_snapshot_list(
805 cpfile, next, next_bh, kaddr);
806 list->ssl_prev = cpu_to_le64(prev);
Cong Wang7b9c0972011-11-25 23:14:33 +0800807 kunmap_atomic(kaddr);
Koji Sato29619802009-04-06 19:01:31 -0700808
Cong Wang7b9c0972011-11-25 23:14:33 +0800809 kaddr = kmap_atomic(prev_bh->b_page);
Koji Sato29619802009-04-06 19:01:31 -0700810 list = nilfs_cpfile_block_get_snapshot_list(
811 cpfile, prev, prev_bh, kaddr);
812 list->ssl_next = cpu_to_le64(next);
Cong Wang7b9c0972011-11-25 23:14:33 +0800813 kunmap_atomic(kaddr);
Koji Sato29619802009-04-06 19:01:31 -0700814
Cong Wang7b9c0972011-11-25 23:14:33 +0800815 kaddr = kmap_atomic(cp_bh->b_page);
Koji Sato29619802009-04-06 19:01:31 -0700816 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
817 cp->cp_snapshot_list.ssl_next = cpu_to_le64(0);
818 cp->cp_snapshot_list.ssl_prev = cpu_to_le64(0);
819 nilfs_checkpoint_clear_snapshot(cp);
Cong Wang7b9c0972011-11-25 23:14:33 +0800820 kunmap_atomic(kaddr);
Koji Sato29619802009-04-06 19:01:31 -0700821
Cong Wang7b9c0972011-11-25 23:14:33 +0800822 kaddr = kmap_atomic(header_bh->b_page);
Koji Sato29619802009-04-06 19:01:31 -0700823 header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr);
824 le64_add_cpu(&header->ch_nsnapshots, -1);
Cong Wang7b9c0972011-11-25 23:14:33 +0800825 kunmap_atomic(kaddr);
Koji Sato29619802009-04-06 19:01:31 -0700826
Ryusuke Konishi5fc7b142011-05-05 12:56:51 +0900827 mark_buffer_dirty(next_bh);
828 mark_buffer_dirty(prev_bh);
829 mark_buffer_dirty(cp_bh);
830 mark_buffer_dirty(header_bh);
Koji Sato29619802009-04-06 19:01:31 -0700831 nilfs_mdt_mark_dirty(cpfile);
832
833 brelse(prev_bh);
834
835 out_next:
836 brelse(next_bh);
837
838 out_header:
839 brelse(header_bh);
840
841 out_cp:
842 brelse(cp_bh);
843
844 out_sem:
845 up_write(&NILFS_MDT(cpfile)->mi_sem);
846 return ret;
847}
848
849/**
850 * nilfs_cpfile_is_snapshot -
851 * @cpfile: inode of checkpoint file
852 * @cno: checkpoint number
853 *
854 * Description:
855 *
856 * Return Value: On success, 1 is returned if the checkpoint specified by
857 * @cno is a snapshot, or 0 if not. On error, one of the following negative
858 * error codes is returned.
859 *
860 * %-EIO - I/O error.
861 *
862 * %-ENOMEM - Insufficient amount of memory available.
863 *
864 * %-ENOENT - No such checkpoint.
865 */
866int nilfs_cpfile_is_snapshot(struct inode *cpfile, __u64 cno)
867{
868 struct buffer_head *bh;
869 struct nilfs_checkpoint *cp;
870 void *kaddr;
871 int ret;
872
Ryusuke Konishi076a3782016-05-23 16:23:48 -0700873 /*
874 * CP number is invalid if it's zero or larger than the
875 * largest existing one.
876 */
Zhu Yanhai43be0ec2009-08-12 14:17:59 +0800877 if (cno == 0 || cno >= nilfs_mdt_cno(cpfile))
878 return -ENOENT;
Koji Sato29619802009-04-06 19:01:31 -0700879 down_read(&NILFS_MDT(cpfile)->mi_sem);
880
881 ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &bh);
882 if (ret < 0)
883 goto out;
Cong Wang7b9c0972011-11-25 23:14:33 +0800884 kaddr = kmap_atomic(bh->b_page);
Koji Sato29619802009-04-06 19:01:31 -0700885 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr);
Zhu Yanhai43be0ec2009-08-12 14:17:59 +0800886 if (nilfs_checkpoint_invalid(cp))
887 ret = -ENOENT;
888 else
889 ret = nilfs_checkpoint_snapshot(cp);
Cong Wang7b9c0972011-11-25 23:14:33 +0800890 kunmap_atomic(kaddr);
Koji Sato29619802009-04-06 19:01:31 -0700891 brelse(bh);
892
893 out:
894 up_read(&NILFS_MDT(cpfile)->mi_sem);
895 return ret;
896}
897
898/**
899 * nilfs_cpfile_change_cpmode - change checkpoint mode
900 * @cpfile: inode of checkpoint file
901 * @cno: checkpoint number
902 * @status: mode of checkpoint
903 *
904 * Description: nilfs_change_cpmode() changes the mode of the checkpoint
905 * specified by @cno. The mode @mode is NILFS_CHECKPOINT or NILFS_SNAPSHOT.
906 *
907 * Return Value: On success, 0 is returned. On error, one of the following
908 * negative error codes is returned.
909 *
910 * %-EIO - I/O error.
911 *
912 * %-ENOMEM - Insufficient amount of memory available.
913 *
914 * %-ENOENT - No such checkpoint.
915 */
916int nilfs_cpfile_change_cpmode(struct inode *cpfile, __u64 cno, int mode)
917{
Koji Sato29619802009-04-06 19:01:31 -0700918 int ret;
919
Koji Sato29619802009-04-06 19:01:31 -0700920 switch (mode) {
921 case NILFS_CHECKPOINT:
Ryusuke Konishi032dbb32010-09-13 11:16:34 +0900922 if (nilfs_checkpoint_is_mounted(cpfile->i_sb, cno))
923 /*
924 * Current implementation does not have to protect
925 * plain read-only mounts since they are exclusive
926 * with a read/write mount and are protected from the
927 * cleaner.
928 */
Koji Sato29619802009-04-06 19:01:31 -0700929 ret = -EBUSY;
Ryusuke Konishi032dbb32010-09-13 11:16:34 +0900930 else
Koji Sato29619802009-04-06 19:01:31 -0700931 ret = nilfs_cpfile_clear_snapshot(cpfile, cno);
Koji Sato29619802009-04-06 19:01:31 -0700932 return ret;
933 case NILFS_SNAPSHOT:
934 return nilfs_cpfile_set_snapshot(cpfile, cno);
935 default:
936 return -EINVAL;
937 }
938}
939
940/**
941 * nilfs_cpfile_get_stat - get checkpoint statistics
942 * @cpfile: inode of checkpoint file
943 * @stat: pointer to a structure of checkpoint statistics
944 *
945 * Description: nilfs_cpfile_get_stat() returns information about checkpoints.
946 *
947 * Return Value: On success, 0 is returned, and checkpoints information is
948 * stored in the place pointed by @stat. On error, one of the following
949 * negative error codes is returned.
950 *
951 * %-EIO - I/O error.
952 *
953 * %-ENOMEM - Insufficient amount of memory available.
954 */
955int nilfs_cpfile_get_stat(struct inode *cpfile, struct nilfs_cpstat *cpstat)
956{
957 struct buffer_head *bh;
958 struct nilfs_cpfile_header *header;
959 void *kaddr;
960 int ret;
961
962 down_read(&NILFS_MDT(cpfile)->mi_sem);
963
964 ret = nilfs_cpfile_get_header_block(cpfile, &bh);
965 if (ret < 0)
966 goto out_sem;
Cong Wang7b9c0972011-11-25 23:14:33 +0800967 kaddr = kmap_atomic(bh->b_page);
Koji Sato29619802009-04-06 19:01:31 -0700968 header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr);
969 cpstat->cs_cno = nilfs_mdt_cno(cpfile);
970 cpstat->cs_ncps = le64_to_cpu(header->ch_ncheckpoints);
971 cpstat->cs_nsss = le64_to_cpu(header->ch_nsnapshots);
Cong Wang7b9c0972011-11-25 23:14:33 +0800972 kunmap_atomic(kaddr);
Koji Sato29619802009-04-06 19:01:31 -0700973 brelse(bh);
974
975 out_sem:
976 up_read(&NILFS_MDT(cpfile)->mi_sem);
977 return ret;
978}
Ryusuke Konishi79739562009-11-12 23:56:43 +0900979
980/**
Ryusuke Konishif1e89c82010-09-05 12:20:59 +0900981 * nilfs_cpfile_read - read or get cpfile inode
982 * @sb: super block instance
Ryusuke Konishi79739562009-11-12 23:56:43 +0900983 * @cpsize: size of a checkpoint entry
Ryusuke Konishif1e89c82010-09-05 12:20:59 +0900984 * @raw_inode: on-disk cpfile inode
985 * @inodep: buffer to store the inode
Ryusuke Konishi79739562009-11-12 23:56:43 +0900986 */
Ryusuke Konishif1e89c82010-09-05 12:20:59 +0900987int nilfs_cpfile_read(struct super_block *sb, size_t cpsize,
988 struct nilfs_inode *raw_inode, struct inode **inodep)
Ryusuke Konishi79739562009-11-12 23:56:43 +0900989{
990 struct inode *cpfile;
Ryusuke Konishif1e89c82010-09-05 12:20:59 +0900991 int err;
Ryusuke Konishi79739562009-11-12 23:56:43 +0900992
Ryusuke Konishi0ec060d2014-04-03 14:50:31 -0700993 if (cpsize > sb->s_blocksize) {
994 printk(KERN_ERR
995 "NILFS: too large checkpoint size: %zu bytes.\n",
996 cpsize);
997 return -EINVAL;
998 } else if (cpsize < NILFS_MIN_CHECKPOINT_SIZE) {
999 printk(KERN_ERR
1000 "NILFS: too small checkpoint size: %zu bytes.\n",
1001 cpsize);
1002 return -EINVAL;
1003 }
1004
Ryusuke Konishif1e89c82010-09-05 12:20:59 +09001005 cpfile = nilfs_iget_locked(sb, NULL, NILFS_CPFILE_INO);
1006 if (unlikely(!cpfile))
1007 return -ENOMEM;
1008 if (!(cpfile->i_state & I_NEW))
1009 goto out;
1010
1011 err = nilfs_mdt_init(cpfile, NILFS_MDT_GFP, 0);
1012 if (err)
1013 goto failed;
1014
1015 nilfs_mdt_set_entry_size(cpfile, cpsize,
1016 sizeof(struct nilfs_cpfile_header));
1017
1018 err = nilfs_read_inode_common(cpfile, raw_inode);
1019 if (err)
1020 goto failed;
1021
1022 unlock_new_inode(cpfile);
1023 out:
1024 *inodep = cpfile;
1025 return 0;
1026 failed:
1027 iget_failed(cpfile);
1028 return err;
Ryusuke Konishi79739562009-11-12 23:56:43 +09001029}