2 * cpfile.c - NILFS checkpoint file.
4 * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
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.
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.
16 * Written by Koji Sato.
19 #include <linux/kernel.h>
21 #include <linux/string.h>
22 #include <linux/buffer_head.h>
23 #include <linux/errno.h>
24 #include <linux/nilfs2_fs.h>
29 static inline unsigned long
30 nilfs_cpfile_checkpoints_per_block(const struct inode
*cpfile
)
32 return NILFS_MDT(cpfile
)->mi_entries_per_block
;
35 /* block number from the beginning of the file */
37 nilfs_cpfile_get_blkoff(const struct inode
*cpfile
, __u64 cno
)
39 __u64 tcno
= cno
+ NILFS_MDT(cpfile
)->mi_first_entry_offset
- 1;
40 do_div(tcno
, nilfs_cpfile_checkpoints_per_block(cpfile
));
41 return (unsigned long)tcno
;
46 nilfs_cpfile_get_offset(const struct inode
*cpfile
, __u64 cno
)
48 __u64 tcno
= cno
+ NILFS_MDT(cpfile
)->mi_first_entry_offset
- 1;
49 return do_div(tcno
, nilfs_cpfile_checkpoints_per_block(cpfile
));
52 static __u64
nilfs_cpfile_first_checkpoint_in_block(const struct inode
*cpfile
,
55 return (__u64
)nilfs_cpfile_checkpoints_per_block(cpfile
) * blkoff
56 + 1 - NILFS_MDT(cpfile
)->mi_first_entry_offset
;
60 nilfs_cpfile_checkpoints_in_block(const struct inode
*cpfile
,
65 nilfs_cpfile_checkpoints_per_block(cpfile
) -
66 nilfs_cpfile_get_offset(cpfile
, curr
),
70 static inline int nilfs_cpfile_is_in_first(const struct inode
*cpfile
,
73 return nilfs_cpfile_get_blkoff(cpfile
, cno
) == 0;
77 nilfs_cpfile_block_add_valid_checkpoints(const struct inode
*cpfile
,
78 struct buffer_head
*bh
,
82 struct nilfs_checkpoint
*cp
= kaddr
+ bh_offset(bh
);
85 count
= le32_to_cpu(cp
->cp_checkpoints_count
) + n
;
86 cp
->cp_checkpoints_count
= cpu_to_le32(count
);
91 nilfs_cpfile_block_sub_valid_checkpoints(const struct inode
*cpfile
,
92 struct buffer_head
*bh
,
96 struct nilfs_checkpoint
*cp
= kaddr
+ bh_offset(bh
);
99 WARN_ON(le32_to_cpu(cp
->cp_checkpoints_count
) < n
);
100 count
= le32_to_cpu(cp
->cp_checkpoints_count
) - n
;
101 cp
->cp_checkpoints_count
= cpu_to_le32(count
);
105 static inline struct nilfs_cpfile_header
*
106 nilfs_cpfile_block_get_header(const struct inode
*cpfile
,
107 struct buffer_head
*bh
,
110 return kaddr
+ bh_offset(bh
);
113 static struct nilfs_checkpoint
*
114 nilfs_cpfile_block_get_checkpoint(const struct inode
*cpfile
, __u64 cno
,
115 struct buffer_head
*bh
,
118 return kaddr
+ bh_offset(bh
) + nilfs_cpfile_get_offset(cpfile
, cno
) *
119 NILFS_MDT(cpfile
)->mi_entry_size
;
122 static void nilfs_cpfile_block_init(struct inode
*cpfile
,
123 struct buffer_head
*bh
,
126 struct nilfs_checkpoint
*cp
= kaddr
+ bh_offset(bh
);
127 size_t cpsz
= NILFS_MDT(cpfile
)->mi_entry_size
;
128 int n
= nilfs_cpfile_checkpoints_per_block(cpfile
);
131 nilfs_checkpoint_set_invalid(cp
);
132 cp
= (void *)cp
+ cpsz
;
136 static inline int nilfs_cpfile_get_header_block(struct inode
*cpfile
,
137 struct buffer_head
**bhp
)
139 return nilfs_mdt_get_block(cpfile
, 0, 0, NULL
, bhp
);
142 static inline int nilfs_cpfile_get_checkpoint_block(struct inode
*cpfile
,
145 struct buffer_head
**bhp
)
147 return nilfs_mdt_get_block(cpfile
,
148 nilfs_cpfile_get_blkoff(cpfile
, cno
),
149 create
, nilfs_cpfile_block_init
, bhp
);
153 * nilfs_cpfile_find_checkpoint_block - find and get a buffer on cpfile
154 * @cpfile: inode of cpfile
155 * @start_cno: start checkpoint number (inclusive)
156 * @end_cno: end checkpoint number (inclusive)
157 * @cnop: place to store the next checkpoint number
158 * @bhp: place to store a pointer to buffer_head struct
160 * Return Value: On success, it returns 0. On error, the following negative
161 * error code is returned.
163 * %-ENOMEM - Insufficient memory available.
167 * %-ENOENT - no block exists in the range.
169 static int nilfs_cpfile_find_checkpoint_block(struct inode
*cpfile
,
170 __u64 start_cno
, __u64 end_cno
,
172 struct buffer_head
**bhp
)
174 unsigned long start
, end
, blkoff
;
177 if (unlikely(start_cno
> end_cno
))
180 start
= nilfs_cpfile_get_blkoff(cpfile
, start_cno
);
181 end
= nilfs_cpfile_get_blkoff(cpfile
, end_cno
);
183 ret
= nilfs_mdt_find_block(cpfile
, start
, end
, &blkoff
, bhp
);
185 *cnop
= (blkoff
== start
) ? start_cno
:
186 nilfs_cpfile_first_checkpoint_in_block(cpfile
, blkoff
);
190 static inline int nilfs_cpfile_delete_checkpoint_block(struct inode
*cpfile
,
193 return nilfs_mdt_delete_block(cpfile
,
194 nilfs_cpfile_get_blkoff(cpfile
, cno
));
198 * nilfs_cpfile_get_checkpoint - get a checkpoint
199 * @cpfile: inode of checkpoint file
200 * @cno: checkpoint number
201 * @create: create flag
202 * @cpp: pointer to a checkpoint
203 * @bhp: pointer to a buffer head
205 * Description: nilfs_cpfile_get_checkpoint() acquires the checkpoint
206 * specified by @cno. A new checkpoint will be created if @cno is the current
207 * checkpoint number and @create is nonzero.
209 * Return Value: On success, 0 is returned, and the checkpoint and the
210 * buffer head of the buffer on which the checkpoint is located are stored in
211 * the place pointed by @cpp and @bhp, respectively. On error, one of the
212 * following negative error codes is returned.
216 * %-ENOMEM - Insufficient amount of memory available.
218 * %-ENOENT - No such checkpoint.
220 * %-EINVAL - invalid checkpoint.
222 int nilfs_cpfile_get_checkpoint(struct inode
*cpfile
,
225 struct nilfs_checkpoint
**cpp
,
226 struct buffer_head
**bhp
)
228 struct buffer_head
*header_bh
, *cp_bh
;
229 struct nilfs_cpfile_header
*header
;
230 struct nilfs_checkpoint
*cp
;
234 if (unlikely(cno
< 1 || cno
> nilfs_mdt_cno(cpfile
) ||
235 (cno
< nilfs_mdt_cno(cpfile
) && create
)))
238 down_write(&NILFS_MDT(cpfile
)->mi_sem
);
240 ret
= nilfs_cpfile_get_header_block(cpfile
, &header_bh
);
243 ret
= nilfs_cpfile_get_checkpoint_block(cpfile
, cno
, create
, &cp_bh
);
246 kaddr
= kmap(cp_bh
->b_page
);
247 cp
= nilfs_cpfile_block_get_checkpoint(cpfile
, cno
, cp_bh
, kaddr
);
248 if (nilfs_checkpoint_invalid(cp
)) {
250 kunmap(cp_bh
->b_page
);
255 /* a newly-created checkpoint */
256 nilfs_checkpoint_clear_invalid(cp
);
257 if (!nilfs_cpfile_is_in_first(cpfile
, cno
))
258 nilfs_cpfile_block_add_valid_checkpoints(cpfile
, cp_bh
,
260 mark_buffer_dirty(cp_bh
);
262 kaddr
= kmap_atomic(header_bh
->b_page
);
263 header
= nilfs_cpfile_block_get_header(cpfile
, header_bh
,
265 le64_add_cpu(&header
->ch_ncheckpoints
, 1);
266 kunmap_atomic(kaddr
);
267 mark_buffer_dirty(header_bh
);
268 nilfs_mdt_mark_dirty(cpfile
);
279 up_write(&NILFS_MDT(cpfile
)->mi_sem
);
284 * nilfs_cpfile_put_checkpoint - put a checkpoint
285 * @cpfile: inode of checkpoint file
286 * @cno: checkpoint number
289 * Description: nilfs_cpfile_put_checkpoint() releases the checkpoint
290 * specified by @cno. @bh must be the buffer head which has been returned by
291 * a previous call to nilfs_cpfile_get_checkpoint() with @cno.
293 void nilfs_cpfile_put_checkpoint(struct inode
*cpfile
, __u64 cno
,
294 struct buffer_head
*bh
)
301 * nilfs_cpfile_delete_checkpoints - delete checkpoints
302 * @cpfile: inode of checkpoint file
303 * @start: start checkpoint number
304 * @end: end checkpoint numer
306 * Description: nilfs_cpfile_delete_checkpoints() deletes the checkpoints in
307 * the period from @start to @end, excluding @end itself. The checkpoints
308 * which have been already deleted are ignored.
310 * Return Value: On success, 0 is returned. On error, one of the following
311 * negative error codes is returned.
315 * %-ENOMEM - Insufficient amount of memory available.
317 * %-EINVAL - invalid checkpoints.
319 int nilfs_cpfile_delete_checkpoints(struct inode
*cpfile
,
323 struct buffer_head
*header_bh
, *cp_bh
;
324 struct nilfs_cpfile_header
*header
;
325 struct nilfs_checkpoint
*cp
;
326 size_t cpsz
= NILFS_MDT(cpfile
)->mi_entry_size
;
329 unsigned long tnicps
;
330 int ret
, ncps
, nicps
, nss
, count
, i
;
332 if (unlikely(start
== 0 || start
> end
)) {
333 printk(KERN_ERR
"%s: invalid range of checkpoint numbers: "
334 "[%llu, %llu)\n", __func__
,
335 (unsigned long long)start
, (unsigned long long)end
);
339 down_write(&NILFS_MDT(cpfile
)->mi_sem
);
341 ret
= nilfs_cpfile_get_header_block(cpfile
, &header_bh
);
347 for (cno
= start
; cno
< end
; cno
+= ncps
) {
348 ncps
= nilfs_cpfile_checkpoints_in_block(cpfile
, cno
, end
);
349 ret
= nilfs_cpfile_get_checkpoint_block(cpfile
, cno
, 0, &cp_bh
);
358 kaddr
= kmap_atomic(cp_bh
->b_page
);
359 cp
= nilfs_cpfile_block_get_checkpoint(
360 cpfile
, cno
, cp_bh
, kaddr
);
362 for (i
= 0; i
< ncps
; i
++, cp
= (void *)cp
+ cpsz
) {
363 if (nilfs_checkpoint_snapshot(cp
)) {
365 } else if (!nilfs_checkpoint_invalid(cp
)) {
366 nilfs_checkpoint_set_invalid(cp
);
372 mark_buffer_dirty(cp_bh
);
373 nilfs_mdt_mark_dirty(cpfile
);
374 if (!nilfs_cpfile_is_in_first(cpfile
, cno
)) {
376 nilfs_cpfile_block_sub_valid_checkpoints(
377 cpfile
, cp_bh
, kaddr
, nicps
);
380 kunmap_atomic(kaddr
);
383 nilfs_cpfile_delete_checkpoint_block(
388 "%s: cannot delete block\n",
395 kunmap_atomic(kaddr
);
400 kaddr
= kmap_atomic(header_bh
->b_page
);
401 header
= nilfs_cpfile_block_get_header(cpfile
, header_bh
,
403 le64_add_cpu(&header
->ch_ncheckpoints
, -(u64
)tnicps
);
404 mark_buffer_dirty(header_bh
);
405 nilfs_mdt_mark_dirty(cpfile
);
406 kunmap_atomic(kaddr
);
414 up_write(&NILFS_MDT(cpfile
)->mi_sem
);
418 static void nilfs_cpfile_checkpoint_to_cpinfo(struct inode
*cpfile
,
419 struct nilfs_checkpoint
*cp
,
420 struct nilfs_cpinfo
*ci
)
422 ci
->ci_flags
= le32_to_cpu(cp
->cp_flags
);
423 ci
->ci_cno
= le64_to_cpu(cp
->cp_cno
);
424 ci
->ci_create
= le64_to_cpu(cp
->cp_create
);
425 ci
->ci_nblk_inc
= le64_to_cpu(cp
->cp_nblk_inc
);
426 ci
->ci_inodes_count
= le64_to_cpu(cp
->cp_inodes_count
);
427 ci
->ci_blocks_count
= le64_to_cpu(cp
->cp_blocks_count
);
428 ci
->ci_next
= le64_to_cpu(cp
->cp_snapshot_list
.ssl_next
);
431 static ssize_t
nilfs_cpfile_do_get_cpinfo(struct inode
*cpfile
, __u64
*cnop
,
432 void *buf
, unsigned cisz
, size_t nci
)
434 struct nilfs_checkpoint
*cp
;
435 struct nilfs_cpinfo
*ci
= buf
;
436 struct buffer_head
*bh
;
437 size_t cpsz
= NILFS_MDT(cpfile
)->mi_entry_size
;
438 __u64 cur_cno
= nilfs_mdt_cno(cpfile
), cno
= *cnop
;
444 return -ENOENT
; /* checkpoint number 0 is invalid */
445 down_read(&NILFS_MDT(cpfile
)->mi_sem
);
447 for (n
= 0; n
< nci
; cno
+= ncps
) {
448 ret
= nilfs_cpfile_find_checkpoint_block(
449 cpfile
, cno
, cur_cno
- 1, &cno
, &bh
);
451 if (likely(ret
== -ENOENT
))
455 ncps
= nilfs_cpfile_checkpoints_in_block(cpfile
, cno
, cur_cno
);
457 kaddr
= kmap_atomic(bh
->b_page
);
458 cp
= nilfs_cpfile_block_get_checkpoint(cpfile
, cno
, bh
, kaddr
);
459 for (i
= 0; i
< ncps
&& n
< nci
; i
++, cp
= (void *)cp
+ cpsz
) {
460 if (!nilfs_checkpoint_invalid(cp
)) {
461 nilfs_cpfile_checkpoint_to_cpinfo(cpfile
, cp
,
463 ci
= (void *)ci
+ cisz
;
467 kunmap_atomic(kaddr
);
473 ci
= (void *)ci
- cisz
;
474 *cnop
= ci
->ci_cno
+ 1;
478 up_read(&NILFS_MDT(cpfile
)->mi_sem
);
482 static ssize_t
nilfs_cpfile_do_get_ssinfo(struct inode
*cpfile
, __u64
*cnop
,
483 void *buf
, unsigned cisz
, size_t nci
)
485 struct buffer_head
*bh
;
486 struct nilfs_cpfile_header
*header
;
487 struct nilfs_checkpoint
*cp
;
488 struct nilfs_cpinfo
*ci
= buf
;
489 __u64 curr
= *cnop
, next
;
490 unsigned long curr_blkoff
, next_blkoff
;
494 down_read(&NILFS_MDT(cpfile
)->mi_sem
);
497 ret
= nilfs_cpfile_get_header_block(cpfile
, &bh
);
500 kaddr
= kmap_atomic(bh
->b_page
);
501 header
= nilfs_cpfile_block_get_header(cpfile
, bh
, kaddr
);
502 curr
= le64_to_cpu(header
->ch_snapshot_list
.ssl_next
);
503 kunmap_atomic(kaddr
);
509 } else if (unlikely(curr
== ~(__u64
)0)) {
514 curr_blkoff
= nilfs_cpfile_get_blkoff(cpfile
, curr
);
515 ret
= nilfs_cpfile_get_checkpoint_block(cpfile
, curr
, 0, &bh
);
516 if (unlikely(ret
< 0)) {
518 ret
= 0; /* No snapshots (started from a hole block) */
521 kaddr
= kmap_atomic(bh
->b_page
);
523 cp
= nilfs_cpfile_block_get_checkpoint(cpfile
, curr
, bh
, kaddr
);
524 curr
= ~(__u64
)0; /* Terminator */
525 if (unlikely(nilfs_checkpoint_invalid(cp
) ||
526 !nilfs_checkpoint_snapshot(cp
)))
528 nilfs_cpfile_checkpoint_to_cpinfo(cpfile
, cp
, ci
);
529 ci
= (void *)ci
+ cisz
;
531 next
= le64_to_cpu(cp
->cp_snapshot_list
.ssl_next
);
533 break; /* reach end of the snapshot list */
535 next_blkoff
= nilfs_cpfile_get_blkoff(cpfile
, next
);
536 if (curr_blkoff
!= next_blkoff
) {
537 kunmap_atomic(kaddr
);
539 ret
= nilfs_cpfile_get_checkpoint_block(cpfile
, next
,
541 if (unlikely(ret
< 0)) {
542 WARN_ON(ret
== -ENOENT
);
545 kaddr
= kmap_atomic(bh
->b_page
);
548 curr_blkoff
= next_blkoff
;
550 kunmap_atomic(kaddr
);
556 up_read(&NILFS_MDT(cpfile
)->mi_sem
);
561 * nilfs_cpfile_get_cpinfo -
568 ssize_t
nilfs_cpfile_get_cpinfo(struct inode
*cpfile
, __u64
*cnop
, int mode
,
569 void *buf
, unsigned cisz
, size_t nci
)
572 case NILFS_CHECKPOINT
:
573 return nilfs_cpfile_do_get_cpinfo(cpfile
, cnop
, buf
, cisz
, nci
);
575 return nilfs_cpfile_do_get_ssinfo(cpfile
, cnop
, buf
, cisz
, nci
);
582 * nilfs_cpfile_delete_checkpoint -
586 int nilfs_cpfile_delete_checkpoint(struct inode
*cpfile
, __u64 cno
)
588 struct nilfs_cpinfo ci
;
592 nci
= nilfs_cpfile_do_get_cpinfo(cpfile
, &tcno
, &ci
, sizeof(ci
), 1);
595 else if (nci
== 0 || ci
.ci_cno
!= cno
)
597 else if (nilfs_cpinfo_snapshot(&ci
))
600 return nilfs_cpfile_delete_checkpoints(cpfile
, cno
, cno
+ 1);
603 static struct nilfs_snapshot_list
*
604 nilfs_cpfile_block_get_snapshot_list(const struct inode
*cpfile
,
606 struct buffer_head
*bh
,
609 struct nilfs_cpfile_header
*header
;
610 struct nilfs_checkpoint
*cp
;
611 struct nilfs_snapshot_list
*list
;
614 cp
= nilfs_cpfile_block_get_checkpoint(cpfile
, cno
, bh
, kaddr
);
615 list
= &cp
->cp_snapshot_list
;
617 header
= nilfs_cpfile_block_get_header(cpfile
, bh
, kaddr
);
618 list
= &header
->ch_snapshot_list
;
623 static int nilfs_cpfile_set_snapshot(struct inode
*cpfile
, __u64 cno
)
625 struct buffer_head
*header_bh
, *curr_bh
, *prev_bh
, *cp_bh
;
626 struct nilfs_cpfile_header
*header
;
627 struct nilfs_checkpoint
*cp
;
628 struct nilfs_snapshot_list
*list
;
630 unsigned long curr_blkoff
, prev_blkoff
;
635 return -ENOENT
; /* checkpoint number 0 is invalid */
636 down_write(&NILFS_MDT(cpfile
)->mi_sem
);
638 ret
= nilfs_cpfile_get_checkpoint_block(cpfile
, cno
, 0, &cp_bh
);
641 kaddr
= kmap_atomic(cp_bh
->b_page
);
642 cp
= nilfs_cpfile_block_get_checkpoint(cpfile
, cno
, cp_bh
, kaddr
);
643 if (nilfs_checkpoint_invalid(cp
)) {
645 kunmap_atomic(kaddr
);
648 if (nilfs_checkpoint_snapshot(cp
)) {
650 kunmap_atomic(kaddr
);
653 kunmap_atomic(kaddr
);
655 ret
= nilfs_cpfile_get_header_block(cpfile
, &header_bh
);
658 kaddr
= kmap_atomic(header_bh
->b_page
);
659 header
= nilfs_cpfile_block_get_header(cpfile
, header_bh
, kaddr
);
660 list
= &header
->ch_snapshot_list
;
665 prev
= le64_to_cpu(list
->ssl_prev
);
667 prev_blkoff
= nilfs_cpfile_get_blkoff(cpfile
, prev
);
669 if (curr_blkoff
!= prev_blkoff
) {
670 kunmap_atomic(kaddr
);
672 ret
= nilfs_cpfile_get_checkpoint_block(cpfile
, curr
,
676 kaddr
= kmap_atomic(curr_bh
->b_page
);
678 curr_blkoff
= prev_blkoff
;
679 cp
= nilfs_cpfile_block_get_checkpoint(
680 cpfile
, curr
, curr_bh
, kaddr
);
681 list
= &cp
->cp_snapshot_list
;
682 prev
= le64_to_cpu(list
->ssl_prev
);
684 kunmap_atomic(kaddr
);
687 ret
= nilfs_cpfile_get_checkpoint_block(cpfile
, prev
, 0,
696 kaddr
= kmap_atomic(curr_bh
->b_page
);
697 list
= nilfs_cpfile_block_get_snapshot_list(
698 cpfile
, curr
, curr_bh
, kaddr
);
699 list
->ssl_prev
= cpu_to_le64(cno
);
700 kunmap_atomic(kaddr
);
702 kaddr
= kmap_atomic(cp_bh
->b_page
);
703 cp
= nilfs_cpfile_block_get_checkpoint(cpfile
, cno
, cp_bh
, kaddr
);
704 cp
->cp_snapshot_list
.ssl_next
= cpu_to_le64(curr
);
705 cp
->cp_snapshot_list
.ssl_prev
= cpu_to_le64(prev
);
706 nilfs_checkpoint_set_snapshot(cp
);
707 kunmap_atomic(kaddr
);
709 kaddr
= kmap_atomic(prev_bh
->b_page
);
710 list
= nilfs_cpfile_block_get_snapshot_list(
711 cpfile
, prev
, prev_bh
, kaddr
);
712 list
->ssl_next
= cpu_to_le64(cno
);
713 kunmap_atomic(kaddr
);
715 kaddr
= kmap_atomic(header_bh
->b_page
);
716 header
= nilfs_cpfile_block_get_header(cpfile
, header_bh
, kaddr
);
717 le64_add_cpu(&header
->ch_nsnapshots
, 1);
718 kunmap_atomic(kaddr
);
720 mark_buffer_dirty(prev_bh
);
721 mark_buffer_dirty(curr_bh
);
722 mark_buffer_dirty(cp_bh
);
723 mark_buffer_dirty(header_bh
);
724 nilfs_mdt_mark_dirty(cpfile
);
738 up_write(&NILFS_MDT(cpfile
)->mi_sem
);
742 static int nilfs_cpfile_clear_snapshot(struct inode
*cpfile
, __u64 cno
)
744 struct buffer_head
*header_bh
, *next_bh
, *prev_bh
, *cp_bh
;
745 struct nilfs_cpfile_header
*header
;
746 struct nilfs_checkpoint
*cp
;
747 struct nilfs_snapshot_list
*list
;
753 return -ENOENT
; /* checkpoint number 0 is invalid */
754 down_write(&NILFS_MDT(cpfile
)->mi_sem
);
756 ret
= nilfs_cpfile_get_checkpoint_block(cpfile
, cno
, 0, &cp_bh
);
759 kaddr
= kmap_atomic(cp_bh
->b_page
);
760 cp
= nilfs_cpfile_block_get_checkpoint(cpfile
, cno
, cp_bh
, kaddr
);
761 if (nilfs_checkpoint_invalid(cp
)) {
763 kunmap_atomic(kaddr
);
766 if (!nilfs_checkpoint_snapshot(cp
)) {
768 kunmap_atomic(kaddr
);
772 list
= &cp
->cp_snapshot_list
;
773 next
= le64_to_cpu(list
->ssl_next
);
774 prev
= le64_to_cpu(list
->ssl_prev
);
775 kunmap_atomic(kaddr
);
777 ret
= nilfs_cpfile_get_header_block(cpfile
, &header_bh
);
781 ret
= nilfs_cpfile_get_checkpoint_block(cpfile
, next
, 0,
790 ret
= nilfs_cpfile_get_checkpoint_block(cpfile
, prev
, 0,
799 kaddr
= kmap_atomic(next_bh
->b_page
);
800 list
= nilfs_cpfile_block_get_snapshot_list(
801 cpfile
, next
, next_bh
, kaddr
);
802 list
->ssl_prev
= cpu_to_le64(prev
);
803 kunmap_atomic(kaddr
);
805 kaddr
= kmap_atomic(prev_bh
->b_page
);
806 list
= nilfs_cpfile_block_get_snapshot_list(
807 cpfile
, prev
, prev_bh
, kaddr
);
808 list
->ssl_next
= cpu_to_le64(next
);
809 kunmap_atomic(kaddr
);
811 kaddr
= kmap_atomic(cp_bh
->b_page
);
812 cp
= nilfs_cpfile_block_get_checkpoint(cpfile
, cno
, cp_bh
, kaddr
);
813 cp
->cp_snapshot_list
.ssl_next
= cpu_to_le64(0);
814 cp
->cp_snapshot_list
.ssl_prev
= cpu_to_le64(0);
815 nilfs_checkpoint_clear_snapshot(cp
);
816 kunmap_atomic(kaddr
);
818 kaddr
= kmap_atomic(header_bh
->b_page
);
819 header
= nilfs_cpfile_block_get_header(cpfile
, header_bh
, kaddr
);
820 le64_add_cpu(&header
->ch_nsnapshots
, -1);
821 kunmap_atomic(kaddr
);
823 mark_buffer_dirty(next_bh
);
824 mark_buffer_dirty(prev_bh
);
825 mark_buffer_dirty(cp_bh
);
826 mark_buffer_dirty(header_bh
);
827 nilfs_mdt_mark_dirty(cpfile
);
841 up_write(&NILFS_MDT(cpfile
)->mi_sem
);
846 * nilfs_cpfile_is_snapshot -
847 * @cpfile: inode of checkpoint file
848 * @cno: checkpoint number
852 * Return Value: On success, 1 is returned if the checkpoint specified by
853 * @cno is a snapshot, or 0 if not. On error, one of the following negative
854 * error codes is returned.
858 * %-ENOMEM - Insufficient amount of memory available.
860 * %-ENOENT - No such checkpoint.
862 int nilfs_cpfile_is_snapshot(struct inode
*cpfile
, __u64 cno
)
864 struct buffer_head
*bh
;
865 struct nilfs_checkpoint
*cp
;
869 /* CP number is invalid if it's zero or larger than the
871 if (cno
== 0 || cno
>= nilfs_mdt_cno(cpfile
))
873 down_read(&NILFS_MDT(cpfile
)->mi_sem
);
875 ret
= nilfs_cpfile_get_checkpoint_block(cpfile
, cno
, 0, &bh
);
878 kaddr
= kmap_atomic(bh
->b_page
);
879 cp
= nilfs_cpfile_block_get_checkpoint(cpfile
, cno
, bh
, kaddr
);
880 if (nilfs_checkpoint_invalid(cp
))
883 ret
= nilfs_checkpoint_snapshot(cp
);
884 kunmap_atomic(kaddr
);
888 up_read(&NILFS_MDT(cpfile
)->mi_sem
);
893 * nilfs_cpfile_change_cpmode - change checkpoint mode
894 * @cpfile: inode of checkpoint file
895 * @cno: checkpoint number
896 * @status: mode of checkpoint
898 * Description: nilfs_change_cpmode() changes the mode of the checkpoint
899 * specified by @cno. The mode @mode is NILFS_CHECKPOINT or NILFS_SNAPSHOT.
901 * Return Value: On success, 0 is returned. On error, one of the following
902 * negative error codes is returned.
906 * %-ENOMEM - Insufficient amount of memory available.
908 * %-ENOENT - No such checkpoint.
910 int nilfs_cpfile_change_cpmode(struct inode
*cpfile
, __u64 cno
, int mode
)
915 case NILFS_CHECKPOINT
:
916 if (nilfs_checkpoint_is_mounted(cpfile
->i_sb
, cno
))
918 * Current implementation does not have to protect
919 * plain read-only mounts since they are exclusive
920 * with a read/write mount and are protected from the
925 ret
= nilfs_cpfile_clear_snapshot(cpfile
, cno
);
928 return nilfs_cpfile_set_snapshot(cpfile
, cno
);
935 * nilfs_cpfile_get_stat - get checkpoint statistics
936 * @cpfile: inode of checkpoint file
937 * @stat: pointer to a structure of checkpoint statistics
939 * Description: nilfs_cpfile_get_stat() returns information about checkpoints.
941 * Return Value: On success, 0 is returned, and checkpoints information is
942 * stored in the place pointed by @stat. On error, one of the following
943 * negative error codes is returned.
947 * %-ENOMEM - Insufficient amount of memory available.
949 int nilfs_cpfile_get_stat(struct inode
*cpfile
, struct nilfs_cpstat
*cpstat
)
951 struct buffer_head
*bh
;
952 struct nilfs_cpfile_header
*header
;
956 down_read(&NILFS_MDT(cpfile
)->mi_sem
);
958 ret
= nilfs_cpfile_get_header_block(cpfile
, &bh
);
961 kaddr
= kmap_atomic(bh
->b_page
);
962 header
= nilfs_cpfile_block_get_header(cpfile
, bh
, kaddr
);
963 cpstat
->cs_cno
= nilfs_mdt_cno(cpfile
);
964 cpstat
->cs_ncps
= le64_to_cpu(header
->ch_ncheckpoints
);
965 cpstat
->cs_nsss
= le64_to_cpu(header
->ch_nsnapshots
);
966 kunmap_atomic(kaddr
);
970 up_read(&NILFS_MDT(cpfile
)->mi_sem
);
975 * nilfs_cpfile_read - read or get cpfile inode
976 * @sb: super block instance
977 * @cpsize: size of a checkpoint entry
978 * @raw_inode: on-disk cpfile inode
979 * @inodep: buffer to store the inode
981 int nilfs_cpfile_read(struct super_block
*sb
, size_t cpsize
,
982 struct nilfs_inode
*raw_inode
, struct inode
**inodep
)
984 struct inode
*cpfile
;
987 if (cpsize
> sb
->s_blocksize
) {
989 "NILFS: too large checkpoint size: %zu bytes.\n",
992 } else if (cpsize
< NILFS_MIN_CHECKPOINT_SIZE
) {
994 "NILFS: too small checkpoint size: %zu bytes.\n",
999 cpfile
= nilfs_iget_locked(sb
, NULL
, NILFS_CPFILE_INO
);
1000 if (unlikely(!cpfile
))
1002 if (!(cpfile
->i_state
& I_NEW
))
1005 err
= nilfs_mdt_init(cpfile
, NILFS_MDT_GFP
, 0);
1009 nilfs_mdt_set_entry_size(cpfile
, cpsize
,
1010 sizeof(struct nilfs_cpfile_header
));
1012 err
= nilfs_read_inode_common(cpfile
, raw_inode
);
1016 unlock_new_inode(cpfile
);
1021 iget_failed(cpfile
);