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 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 * Written by Koji Sato <koji@osrg.net>.
23 #include <linux/kernel.h>
25 #include <linux/string.h>
26 #include <linux/buffer_head.h>
27 #include <linux/errno.h>
28 #include <linux/nilfs2_fs.h>
33 static inline unsigned long
34 nilfs_cpfile_checkpoints_per_block(const struct inode *cpfile)
36 return NILFS_MDT(cpfile)->mi_entries_per_block;
39 /* block number from the beginning of the file */
41 nilfs_cpfile_get_blkoff(const struct inode *cpfile, __u64 cno)
43 __u64 tcno = cno + NILFS_MDT(cpfile)->mi_first_entry_offset - 1;
44 do_div(tcno, nilfs_cpfile_checkpoints_per_block(cpfile));
45 return (unsigned long)tcno;
50 nilfs_cpfile_get_offset(const struct inode *cpfile, __u64 cno)
52 __u64 tcno = cno + NILFS_MDT(cpfile)->mi_first_entry_offset - 1;
53 return do_div(tcno, nilfs_cpfile_checkpoints_per_block(cpfile));
56 static __u64 nilfs_cpfile_first_checkpoint_in_block(const struct inode *cpfile,
59 return (__u64)nilfs_cpfile_checkpoints_per_block(cpfile) * blkoff
60 + 1 - NILFS_MDT(cpfile)->mi_first_entry_offset;
64 nilfs_cpfile_checkpoints_in_block(const struct inode *cpfile,
69 nilfs_cpfile_checkpoints_per_block(cpfile) -
70 nilfs_cpfile_get_offset(cpfile, curr),
74 static inline int nilfs_cpfile_is_in_first(const struct inode *cpfile,
77 return nilfs_cpfile_get_blkoff(cpfile, cno) == 0;
81 nilfs_cpfile_block_add_valid_checkpoints(const struct inode *cpfile,
82 struct buffer_head *bh,
86 struct nilfs_checkpoint *cp = kaddr + bh_offset(bh);
89 count = le32_to_cpu(cp->cp_checkpoints_count) + n;
90 cp->cp_checkpoints_count = cpu_to_le32(count);
95 nilfs_cpfile_block_sub_valid_checkpoints(const struct inode *cpfile,
96 struct buffer_head *bh,
100 struct nilfs_checkpoint *cp = kaddr + bh_offset(bh);
103 WARN_ON(le32_to_cpu(cp->cp_checkpoints_count) < n);
104 count = le32_to_cpu(cp->cp_checkpoints_count) - n;
105 cp->cp_checkpoints_count = cpu_to_le32(count);
109 static inline struct nilfs_cpfile_header *
110 nilfs_cpfile_block_get_header(const struct inode *cpfile,
111 struct buffer_head *bh,
114 return kaddr + bh_offset(bh);
117 static struct nilfs_checkpoint *
118 nilfs_cpfile_block_get_checkpoint(const struct inode *cpfile, __u64 cno,
119 struct buffer_head *bh,
122 return kaddr + bh_offset(bh) + nilfs_cpfile_get_offset(cpfile, cno) *
123 NILFS_MDT(cpfile)->mi_entry_size;
126 static void nilfs_cpfile_block_init(struct inode *cpfile,
127 struct buffer_head *bh,
130 struct nilfs_checkpoint *cp = kaddr + bh_offset(bh);
131 size_t cpsz = NILFS_MDT(cpfile)->mi_entry_size;
132 int n = nilfs_cpfile_checkpoints_per_block(cpfile);
135 nilfs_checkpoint_set_invalid(cp);
136 cp = (void *)cp + cpsz;
140 static inline int nilfs_cpfile_get_header_block(struct inode *cpfile,
141 struct buffer_head **bhp)
143 return nilfs_mdt_get_block(cpfile, 0, 0, NULL, bhp);
146 static inline int nilfs_cpfile_get_checkpoint_block(struct inode *cpfile,
149 struct buffer_head **bhp)
151 return nilfs_mdt_get_block(cpfile,
152 nilfs_cpfile_get_blkoff(cpfile, cno),
153 create, nilfs_cpfile_block_init, bhp);
157 * nilfs_cpfile_find_checkpoint_block - find and get a buffer on cpfile
158 * @cpfile: inode of cpfile
159 * @start_cno: start checkpoint number (inclusive)
160 * @end_cno: end checkpoint number (inclusive)
161 * @cnop: place to store the next checkpoint number
162 * @bhp: place to store a pointer to buffer_head struct
164 * Return Value: On success, it returns 0. On error, the following negative
165 * error code is returned.
167 * %-ENOMEM - Insufficient memory available.
171 * %-ENOENT - no block exists in the range.
173 static int nilfs_cpfile_find_checkpoint_block(struct inode *cpfile,
174 __u64 start_cno, __u64 end_cno,
176 struct buffer_head **bhp)
178 unsigned long start, end, blkoff;
181 if (unlikely(start_cno > end_cno))
184 start = nilfs_cpfile_get_blkoff(cpfile, start_cno);
185 end = nilfs_cpfile_get_blkoff(cpfile, end_cno);
187 ret = nilfs_mdt_find_block(cpfile, start, end, &blkoff, bhp);
189 *cnop = (blkoff == start) ? start_cno :
190 nilfs_cpfile_first_checkpoint_in_block(cpfile, blkoff);
194 static inline int nilfs_cpfile_delete_checkpoint_block(struct inode *cpfile,
197 return nilfs_mdt_delete_block(cpfile,
198 nilfs_cpfile_get_blkoff(cpfile, cno));
202 * nilfs_cpfile_get_checkpoint - get a checkpoint
203 * @cpfile: inode of checkpoint file
204 * @cno: checkpoint number
205 * @create: create flag
206 * @cpp: pointer to a checkpoint
207 * @bhp: pointer to a buffer head
209 * Description: nilfs_cpfile_get_checkpoint() acquires the checkpoint
210 * specified by @cno. A new checkpoint will be created if @cno is the current
211 * checkpoint number and @create is nonzero.
213 * Return Value: On success, 0 is returned, and the checkpoint and the
214 * buffer head of the buffer on which the checkpoint is located are stored in
215 * the place pointed by @cpp and @bhp, respectively. On error, one of the
216 * following negative error codes is returned.
220 * %-ENOMEM - Insufficient amount of memory available.
222 * %-ENOENT - No such checkpoint.
224 * %-EINVAL - invalid checkpoint.
226 int nilfs_cpfile_get_checkpoint(struct inode *cpfile,
229 struct nilfs_checkpoint **cpp,
230 struct buffer_head **bhp)
232 struct buffer_head *header_bh, *cp_bh;
233 struct nilfs_cpfile_header *header;
234 struct nilfs_checkpoint *cp;
238 if (unlikely(cno < 1 || cno > nilfs_mdt_cno(cpfile) ||
239 (cno < nilfs_mdt_cno(cpfile) && create)))
242 down_write(&NILFS_MDT(cpfile)->mi_sem);
244 ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
247 ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, create, &cp_bh);
250 kaddr = kmap(cp_bh->b_page);
251 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
252 if (nilfs_checkpoint_invalid(cp)) {
254 kunmap(cp_bh->b_page);
259 /* a newly-created checkpoint */
260 nilfs_checkpoint_clear_invalid(cp);
261 if (!nilfs_cpfile_is_in_first(cpfile, cno))
262 nilfs_cpfile_block_add_valid_checkpoints(cpfile, cp_bh,
264 mark_buffer_dirty(cp_bh);
266 kaddr = kmap_atomic(header_bh->b_page);
267 header = nilfs_cpfile_block_get_header(cpfile, header_bh,
269 le64_add_cpu(&header->ch_ncheckpoints, 1);
270 kunmap_atomic(kaddr);
271 mark_buffer_dirty(header_bh);
272 nilfs_mdt_mark_dirty(cpfile);
283 up_write(&NILFS_MDT(cpfile)->mi_sem);
288 * nilfs_cpfile_put_checkpoint - put a checkpoint
289 * @cpfile: inode of checkpoint file
290 * @cno: checkpoint number
293 * Description: nilfs_cpfile_put_checkpoint() releases the checkpoint
294 * specified by @cno. @bh must be the buffer head which has been returned by
295 * a previous call to nilfs_cpfile_get_checkpoint() with @cno.
297 void nilfs_cpfile_put_checkpoint(struct inode *cpfile, __u64 cno,
298 struct buffer_head *bh)
305 * nilfs_cpfile_delete_checkpoints - delete checkpoints
306 * @cpfile: inode of checkpoint file
307 * @start: start checkpoint number
308 * @end: end checkpoint numer
310 * Description: nilfs_cpfile_delete_checkpoints() deletes the checkpoints in
311 * the period from @start to @end, excluding @end itself. The checkpoints
312 * which have been already deleted are ignored.
314 * Return Value: On success, 0 is returned. On error, one of the following
315 * negative error codes is returned.
319 * %-ENOMEM - Insufficient amount of memory available.
321 * %-EINVAL - invalid checkpoints.
323 int nilfs_cpfile_delete_checkpoints(struct inode *cpfile,
327 struct buffer_head *header_bh, *cp_bh;
328 struct nilfs_cpfile_header *header;
329 struct nilfs_checkpoint *cp;
330 size_t cpsz = NILFS_MDT(cpfile)->mi_entry_size;
333 unsigned long tnicps;
334 int ret, ncps, nicps, nss, count, i;
336 if (unlikely(start == 0 || start > end)) {
337 printk(KERN_ERR "%s: invalid range of checkpoint numbers: "
338 "[%llu, %llu)\n", __func__,
339 (unsigned long long)start, (unsigned long long)end);
343 down_write(&NILFS_MDT(cpfile)->mi_sem);
345 ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
351 for (cno = start; cno < end; cno += ncps) {
352 ncps = nilfs_cpfile_checkpoints_in_block(cpfile, cno, end);
353 ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh);
362 kaddr = kmap_atomic(cp_bh->b_page);
363 cp = nilfs_cpfile_block_get_checkpoint(
364 cpfile, cno, cp_bh, kaddr);
366 for (i = 0; i < ncps; i++, cp = (void *)cp + cpsz) {
367 if (nilfs_checkpoint_snapshot(cp)) {
369 } else if (!nilfs_checkpoint_invalid(cp)) {
370 nilfs_checkpoint_set_invalid(cp);
376 mark_buffer_dirty(cp_bh);
377 nilfs_mdt_mark_dirty(cpfile);
378 if (!nilfs_cpfile_is_in_first(cpfile, cno)) {
380 nilfs_cpfile_block_sub_valid_checkpoints(
381 cpfile, cp_bh, kaddr, nicps);
384 kunmap_atomic(kaddr);
387 nilfs_cpfile_delete_checkpoint_block(
392 "%s: cannot delete block\n",
399 kunmap_atomic(kaddr);
404 kaddr = kmap_atomic(header_bh->b_page);
405 header = nilfs_cpfile_block_get_header(cpfile, header_bh,
407 le64_add_cpu(&header->ch_ncheckpoints, -(u64)tnicps);
408 mark_buffer_dirty(header_bh);
409 nilfs_mdt_mark_dirty(cpfile);
410 kunmap_atomic(kaddr);
418 up_write(&NILFS_MDT(cpfile)->mi_sem);
422 static void nilfs_cpfile_checkpoint_to_cpinfo(struct inode *cpfile,
423 struct nilfs_checkpoint *cp,
424 struct nilfs_cpinfo *ci)
426 ci->ci_flags = le32_to_cpu(cp->cp_flags);
427 ci->ci_cno = le64_to_cpu(cp->cp_cno);
428 ci->ci_create = le64_to_cpu(cp->cp_create);
429 ci->ci_nblk_inc = le64_to_cpu(cp->cp_nblk_inc);
430 ci->ci_inodes_count = le64_to_cpu(cp->cp_inodes_count);
431 ci->ci_blocks_count = le64_to_cpu(cp->cp_blocks_count);
432 ci->ci_next = le64_to_cpu(cp->cp_snapshot_list.ssl_next);
435 static ssize_t nilfs_cpfile_do_get_cpinfo(struct inode *cpfile, __u64 *cnop,
436 void *buf, unsigned cisz, size_t nci)
438 struct nilfs_checkpoint *cp;
439 struct nilfs_cpinfo *ci = buf;
440 struct buffer_head *bh;
441 size_t cpsz = NILFS_MDT(cpfile)->mi_entry_size;
442 __u64 cur_cno = nilfs_mdt_cno(cpfile), cno = *cnop;
448 return -ENOENT; /* checkpoint number 0 is invalid */
449 down_read(&NILFS_MDT(cpfile)->mi_sem);
451 for (n = 0; n < nci; cno += ncps) {
452 ret = nilfs_cpfile_find_checkpoint_block(
453 cpfile, cno, cur_cno - 1, &cno, &bh);
455 if (likely(ret == -ENOENT))
459 ncps = nilfs_cpfile_checkpoints_in_block(cpfile, cno, cur_cno);
461 kaddr = kmap_atomic(bh->b_page);
462 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr);
463 for (i = 0; i < ncps && n < nci; i++, cp = (void *)cp + cpsz) {
464 if (!nilfs_checkpoint_invalid(cp)) {
465 nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp,
467 ci = (void *)ci + cisz;
471 kunmap_atomic(kaddr);
477 ci = (void *)ci - cisz;
478 *cnop = ci->ci_cno + 1;
482 up_read(&NILFS_MDT(cpfile)->mi_sem);
486 static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 *cnop,
487 void *buf, unsigned cisz, size_t nci)
489 struct buffer_head *bh;
490 struct nilfs_cpfile_header *header;
491 struct nilfs_checkpoint *cp;
492 struct nilfs_cpinfo *ci = buf;
493 __u64 curr = *cnop, next;
494 unsigned long curr_blkoff, next_blkoff;
498 down_read(&NILFS_MDT(cpfile)->mi_sem);
501 ret = nilfs_cpfile_get_header_block(cpfile, &bh);
504 kaddr = kmap_atomic(bh->b_page);
505 header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr);
506 curr = le64_to_cpu(header->ch_snapshot_list.ssl_next);
507 kunmap_atomic(kaddr);
513 } else if (unlikely(curr == ~(__u64)0)) {
518 curr_blkoff = nilfs_cpfile_get_blkoff(cpfile, curr);
519 ret = nilfs_cpfile_get_checkpoint_block(cpfile, curr, 0, &bh);
520 if (unlikely(ret < 0)) {
522 ret = 0; /* No snapshots (started from a hole block) */
525 kaddr = kmap_atomic(bh->b_page);
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)))
532 nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp, ci);
533 ci = (void *)ci + cisz;
535 next = le64_to_cpu(cp->cp_snapshot_list.ssl_next);
537 break; /* reach end of the snapshot list */
539 next_blkoff = nilfs_cpfile_get_blkoff(cpfile, next);
540 if (curr_blkoff != next_blkoff) {
541 kunmap_atomic(kaddr);
543 ret = nilfs_cpfile_get_checkpoint_block(cpfile, next,
545 if (unlikely(ret < 0)) {
546 WARN_ON(ret == -ENOENT);
549 kaddr = kmap_atomic(bh->b_page);
552 curr_blkoff = next_blkoff;
554 kunmap_atomic(kaddr);
560 up_read(&NILFS_MDT(cpfile)->mi_sem);
565 * nilfs_cpfile_get_cpinfo -
572 ssize_t nilfs_cpfile_get_cpinfo(struct inode *cpfile, __u64 *cnop, int mode,
573 void *buf, unsigned cisz, size_t nci)
576 case NILFS_CHECKPOINT:
577 return nilfs_cpfile_do_get_cpinfo(cpfile, cnop, buf, cisz, nci);
579 return nilfs_cpfile_do_get_ssinfo(cpfile, cnop, buf, cisz, nci);
586 * nilfs_cpfile_delete_checkpoint -
590 int nilfs_cpfile_delete_checkpoint(struct inode *cpfile, __u64 cno)
592 struct nilfs_cpinfo ci;
596 nci = nilfs_cpfile_do_get_cpinfo(cpfile, &tcno, &ci, sizeof(ci), 1);
599 else if (nci == 0 || ci.ci_cno != cno)
601 else if (nilfs_cpinfo_snapshot(&ci))
604 return nilfs_cpfile_delete_checkpoints(cpfile, cno, cno + 1);
607 static struct nilfs_snapshot_list *
608 nilfs_cpfile_block_get_snapshot_list(const struct inode *cpfile,
610 struct buffer_head *bh,
613 struct nilfs_cpfile_header *header;
614 struct nilfs_checkpoint *cp;
615 struct nilfs_snapshot_list *list;
618 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr);
619 list = &cp->cp_snapshot_list;
621 header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr);
622 list = &header->ch_snapshot_list;
627 static int nilfs_cpfile_set_snapshot(struct inode *cpfile, __u64 cno)
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;
634 unsigned long curr_blkoff, prev_blkoff;
639 return -ENOENT; /* checkpoint number 0 is invalid */
640 down_write(&NILFS_MDT(cpfile)->mi_sem);
642 ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh);
645 kaddr = kmap_atomic(cp_bh->b_page);
646 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
647 if (nilfs_checkpoint_invalid(cp)) {
649 kunmap_atomic(kaddr);
652 if (nilfs_checkpoint_snapshot(cp)) {
654 kunmap_atomic(kaddr);
657 kunmap_atomic(kaddr);
659 ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
662 kaddr = kmap_atomic(header_bh->b_page);
663 header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr);
664 list = &header->ch_snapshot_list;
669 prev = le64_to_cpu(list->ssl_prev);
671 prev_blkoff = nilfs_cpfile_get_blkoff(cpfile, prev);
673 if (curr_blkoff != prev_blkoff) {
674 kunmap_atomic(kaddr);
676 ret = nilfs_cpfile_get_checkpoint_block(cpfile, curr,
680 kaddr = kmap_atomic(curr_bh->b_page);
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);
688 kunmap_atomic(kaddr);
691 ret = nilfs_cpfile_get_checkpoint_block(cpfile, prev, 0,
700 kaddr = kmap_atomic(curr_bh->b_page);
701 list = nilfs_cpfile_block_get_snapshot_list(
702 cpfile, curr, curr_bh, kaddr);
703 list->ssl_prev = cpu_to_le64(cno);
704 kunmap_atomic(kaddr);
706 kaddr = kmap_atomic(cp_bh->b_page);
707 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);
711 kunmap_atomic(kaddr);
713 kaddr = kmap_atomic(prev_bh->b_page);
714 list = nilfs_cpfile_block_get_snapshot_list(
715 cpfile, prev, prev_bh, kaddr);
716 list->ssl_next = cpu_to_le64(cno);
717 kunmap_atomic(kaddr);
719 kaddr = kmap_atomic(header_bh->b_page);
720 header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr);
721 le64_add_cpu(&header->ch_nsnapshots, 1);
722 kunmap_atomic(kaddr);
724 mark_buffer_dirty(prev_bh);
725 mark_buffer_dirty(curr_bh);
726 mark_buffer_dirty(cp_bh);
727 mark_buffer_dirty(header_bh);
728 nilfs_mdt_mark_dirty(cpfile);
742 up_write(&NILFS_MDT(cpfile)->mi_sem);
746 static int nilfs_cpfile_clear_snapshot(struct inode *cpfile, __u64 cno)
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;
757 return -ENOENT; /* checkpoint number 0 is invalid */
758 down_write(&NILFS_MDT(cpfile)->mi_sem);
760 ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh);
763 kaddr = kmap_atomic(cp_bh->b_page);
764 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
765 if (nilfs_checkpoint_invalid(cp)) {
767 kunmap_atomic(kaddr);
770 if (!nilfs_checkpoint_snapshot(cp)) {
772 kunmap_atomic(kaddr);
776 list = &cp->cp_snapshot_list;
777 next = le64_to_cpu(list->ssl_next);
778 prev = le64_to_cpu(list->ssl_prev);
779 kunmap_atomic(kaddr);
781 ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
785 ret = nilfs_cpfile_get_checkpoint_block(cpfile, next, 0,
794 ret = nilfs_cpfile_get_checkpoint_block(cpfile, prev, 0,
803 kaddr = kmap_atomic(next_bh->b_page);
804 list = nilfs_cpfile_block_get_snapshot_list(
805 cpfile, next, next_bh, kaddr);
806 list->ssl_prev = cpu_to_le64(prev);
807 kunmap_atomic(kaddr);
809 kaddr = kmap_atomic(prev_bh->b_page);
810 list = nilfs_cpfile_block_get_snapshot_list(
811 cpfile, prev, prev_bh, kaddr);
812 list->ssl_next = cpu_to_le64(next);
813 kunmap_atomic(kaddr);
815 kaddr = kmap_atomic(cp_bh->b_page);
816 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);
820 kunmap_atomic(kaddr);
822 kaddr = kmap_atomic(header_bh->b_page);
823 header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr);
824 le64_add_cpu(&header->ch_nsnapshots, -1);
825 kunmap_atomic(kaddr);
827 mark_buffer_dirty(next_bh);
828 mark_buffer_dirty(prev_bh);
829 mark_buffer_dirty(cp_bh);
830 mark_buffer_dirty(header_bh);
831 nilfs_mdt_mark_dirty(cpfile);
845 up_write(&NILFS_MDT(cpfile)->mi_sem);
850 * nilfs_cpfile_is_snapshot -
851 * @cpfile: inode of checkpoint file
852 * @cno: checkpoint number
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.
862 * %-ENOMEM - Insufficient amount of memory available.
864 * %-ENOENT - No such checkpoint.
866 int nilfs_cpfile_is_snapshot(struct inode *cpfile, __u64 cno)
868 struct buffer_head *bh;
869 struct nilfs_checkpoint *cp;
873 /* CP number is invalid if it's zero or larger than the
875 if (cno == 0 || cno >= nilfs_mdt_cno(cpfile))
877 down_read(&NILFS_MDT(cpfile)->mi_sem);
879 ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &bh);
882 kaddr = kmap_atomic(bh->b_page);
883 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr);
884 if (nilfs_checkpoint_invalid(cp))
887 ret = nilfs_checkpoint_snapshot(cp);
888 kunmap_atomic(kaddr);
892 up_read(&NILFS_MDT(cpfile)->mi_sem);
897 * nilfs_cpfile_change_cpmode - change checkpoint mode
898 * @cpfile: inode of checkpoint file
899 * @cno: checkpoint number
900 * @status: mode of checkpoint
902 * Description: nilfs_change_cpmode() changes the mode of the checkpoint
903 * specified by @cno. The mode @mode is NILFS_CHECKPOINT or NILFS_SNAPSHOT.
905 * Return Value: On success, 0 is returned. On error, one of the following
906 * negative error codes is returned.
910 * %-ENOMEM - Insufficient amount of memory available.
912 * %-ENOENT - No such checkpoint.
914 int nilfs_cpfile_change_cpmode(struct inode *cpfile, __u64 cno, int mode)
919 case NILFS_CHECKPOINT:
920 if (nilfs_checkpoint_is_mounted(cpfile->i_sb, cno))
922 * Current implementation does not have to protect
923 * plain read-only mounts since they are exclusive
924 * with a read/write mount and are protected from the
929 ret = nilfs_cpfile_clear_snapshot(cpfile, cno);
932 return nilfs_cpfile_set_snapshot(cpfile, cno);
939 * nilfs_cpfile_get_stat - get checkpoint statistics
940 * @cpfile: inode of checkpoint file
941 * @stat: pointer to a structure of checkpoint statistics
943 * Description: nilfs_cpfile_get_stat() returns information about checkpoints.
945 * Return Value: On success, 0 is returned, and checkpoints information is
946 * stored in the place pointed by @stat. On error, one of the following
947 * negative error codes is returned.
951 * %-ENOMEM - Insufficient amount of memory available.
953 int nilfs_cpfile_get_stat(struct inode *cpfile, struct nilfs_cpstat *cpstat)
955 struct buffer_head *bh;
956 struct nilfs_cpfile_header *header;
960 down_read(&NILFS_MDT(cpfile)->mi_sem);
962 ret = nilfs_cpfile_get_header_block(cpfile, &bh);
965 kaddr = kmap_atomic(bh->b_page);
966 header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr);
967 cpstat->cs_cno = nilfs_mdt_cno(cpfile);
968 cpstat->cs_ncps = le64_to_cpu(header->ch_ncheckpoints);
969 cpstat->cs_nsss = le64_to_cpu(header->ch_nsnapshots);
970 kunmap_atomic(kaddr);
974 up_read(&NILFS_MDT(cpfile)->mi_sem);
979 * nilfs_cpfile_read - read or get cpfile inode
980 * @sb: super block instance
981 * @cpsize: size of a checkpoint entry
982 * @raw_inode: on-disk cpfile inode
983 * @inodep: buffer to store the inode
985 int nilfs_cpfile_read(struct super_block *sb, size_t cpsize,
986 struct nilfs_inode *raw_inode, struct inode **inodep)
988 struct inode *cpfile;
991 if (cpsize > sb->s_blocksize) {
993 "NILFS: too large checkpoint size: %zu bytes.\n",
996 } else if (cpsize < NILFS_MIN_CHECKPOINT_SIZE) {
998 "NILFS: too small checkpoint size: %zu bytes.\n",
1003 cpfile = nilfs_iget_locked(sb, NULL, NILFS_CPFILE_INO);
1004 if (unlikely(!cpfile))
1006 if (!(cpfile->i_state & I_NEW))
1009 err = nilfs_mdt_init(cpfile, NILFS_MDT_GFP, 0);
1013 nilfs_mdt_set_entry_size(cpfile, cpsize,
1014 sizeof(struct nilfs_cpfile_header));
1016 err = nilfs_read_inode_common(cpfile, raw_inode);
1020 unlock_new_inode(cpfile);
1025 iget_failed(cpfile);