2 * the_nilfs.c - the_nilfs shared structure.
4 * Copyright (C) 2005-2008 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 Ryusuke Konishi.
20 #include <linux/buffer_head.h>
21 #include <linux/slab.h>
22 #include <linux/blkdev.h>
23 #include <linux/backing-dev.h>
24 #include <linux/random.h>
25 #include <linux/crc32.h>
35 static int nilfs_valid_sb(struct nilfs_super_block
*sbp
);
37 void nilfs_set_last_segment(struct the_nilfs
*nilfs
,
38 sector_t start_blocknr
, u64 seq
, __u64 cno
)
40 spin_lock(&nilfs
->ns_last_segment_lock
);
41 nilfs
->ns_last_pseg
= start_blocknr
;
42 nilfs
->ns_last_seq
= seq
;
43 nilfs
->ns_last_cno
= cno
;
45 if (!nilfs_sb_dirty(nilfs
)) {
46 if (nilfs
->ns_prev_seq
== nilfs
->ns_last_seq
)
49 set_nilfs_sb_dirty(nilfs
);
51 nilfs
->ns_prev_seq
= nilfs
->ns_last_seq
;
54 spin_unlock(&nilfs
->ns_last_segment_lock
);
58 * alloc_nilfs - allocate a nilfs object
59 * @bdev: block device to which the_nilfs is related
61 * Return Value: On success, pointer to the_nilfs is returned.
62 * On error, NULL is returned.
64 struct the_nilfs
*alloc_nilfs(struct block_device
*bdev
)
66 struct the_nilfs
*nilfs
;
68 nilfs
= kzalloc(sizeof(*nilfs
), GFP_KERNEL
);
72 nilfs
->ns_bdev
= bdev
;
73 atomic_set(&nilfs
->ns_ndirtyblks
, 0);
74 init_rwsem(&nilfs
->ns_sem
);
75 mutex_init(&nilfs
->ns_snapshot_mount_mutex
);
76 INIT_LIST_HEAD(&nilfs
->ns_dirty_files
);
77 INIT_LIST_HEAD(&nilfs
->ns_gc_inodes
);
78 spin_lock_init(&nilfs
->ns_inode_lock
);
79 spin_lock_init(&nilfs
->ns_next_gen_lock
);
80 spin_lock_init(&nilfs
->ns_last_segment_lock
);
81 nilfs
->ns_cptree
= RB_ROOT
;
82 spin_lock_init(&nilfs
->ns_cptree_lock
);
83 init_rwsem(&nilfs
->ns_segctor_sem
);
84 nilfs
->ns_sb_update_freq
= NILFS_SB_FREQ
;
90 * destroy_nilfs - destroy nilfs object
91 * @nilfs: nilfs object to be released
93 void destroy_nilfs(struct the_nilfs
*nilfs
)
96 if (nilfs_init(nilfs
)) {
97 nilfs_sysfs_delete_device_group(nilfs
);
98 brelse(nilfs
->ns_sbh
[0]);
99 brelse(nilfs
->ns_sbh
[1]);
104 static int nilfs_load_super_root(struct the_nilfs
*nilfs
,
105 struct super_block
*sb
, sector_t sr_block
)
107 struct buffer_head
*bh_sr
;
108 struct nilfs_super_root
*raw_sr
;
109 struct nilfs_super_block
**sbp
= nilfs
->ns_sbp
;
110 struct nilfs_inode
*rawi
;
111 unsigned int dat_entry_size
, segment_usage_size
, checkpoint_size
;
112 unsigned int inode_size
;
115 err
= nilfs_read_super_root_block(nilfs
, sr_block
, &bh_sr
, 1);
119 down_read(&nilfs
->ns_sem
);
120 dat_entry_size
= le16_to_cpu(sbp
[0]->s_dat_entry_size
);
121 checkpoint_size
= le16_to_cpu(sbp
[0]->s_checkpoint_size
);
122 segment_usage_size
= le16_to_cpu(sbp
[0]->s_segment_usage_size
);
123 up_read(&nilfs
->ns_sem
);
125 inode_size
= nilfs
->ns_inode_size
;
127 rawi
= (void *)bh_sr
->b_data
+ NILFS_SR_DAT_OFFSET(inode_size
);
128 err
= nilfs_dat_read(sb
, dat_entry_size
, rawi
, &nilfs
->ns_dat
);
132 rawi
= (void *)bh_sr
->b_data
+ NILFS_SR_CPFILE_OFFSET(inode_size
);
133 err
= nilfs_cpfile_read(sb
, checkpoint_size
, rawi
, &nilfs
->ns_cpfile
);
137 rawi
= (void *)bh_sr
->b_data
+ NILFS_SR_SUFILE_OFFSET(inode_size
);
138 err
= nilfs_sufile_read(sb
, segment_usage_size
, rawi
,
143 raw_sr
= (struct nilfs_super_root
*)bh_sr
->b_data
;
144 nilfs
->ns_nongc_ctime
= le64_to_cpu(raw_sr
->sr_nongc_ctime
);
151 iput(nilfs
->ns_cpfile
);
158 static void nilfs_init_recovery_info(struct nilfs_recovery_info
*ri
)
160 memset(ri
, 0, sizeof(*ri
));
161 INIT_LIST_HEAD(&ri
->ri_used_segments
);
164 static void nilfs_clear_recovery_info(struct nilfs_recovery_info
*ri
)
166 nilfs_dispose_segment_list(&ri
->ri_used_segments
);
170 * nilfs_store_log_cursor - load log cursor from a super block
171 * @nilfs: nilfs object
172 * @sbp: buffer storing super block to be read
174 * nilfs_store_log_cursor() reads the last position of the log
175 * containing a super root from a given super block, and initializes
176 * relevant information on the nilfs object preparatory for log
177 * scanning and recovery.
179 static int nilfs_store_log_cursor(struct the_nilfs
*nilfs
,
180 struct nilfs_super_block
*sbp
)
184 nilfs
->ns_last_pseg
= le64_to_cpu(sbp
->s_last_pseg
);
185 nilfs
->ns_last_cno
= le64_to_cpu(sbp
->s_last_cno
);
186 nilfs
->ns_last_seq
= le64_to_cpu(sbp
->s_last_seq
);
188 nilfs
->ns_prev_seq
= nilfs
->ns_last_seq
;
189 nilfs
->ns_seg_seq
= nilfs
->ns_last_seq
;
191 nilfs_get_segnum_of_block(nilfs
, nilfs
->ns_last_pseg
);
192 nilfs
->ns_cno
= nilfs
->ns_last_cno
+ 1;
193 if (nilfs
->ns_segnum
>= nilfs
->ns_nsegments
) {
194 printk(KERN_ERR
"NILFS invalid last segment number.\n");
201 * load_nilfs - load and recover the nilfs
202 * @nilfs: the_nilfs structure to be released
203 * @sb: super block isntance used to recover past segment
205 * load_nilfs() searches and load the latest super root,
206 * attaches the last segment, and does recovery if needed.
207 * The caller must call this exclusively for simultaneous mounts.
209 int load_nilfs(struct the_nilfs
*nilfs
, struct super_block
*sb
)
211 struct nilfs_recovery_info ri
;
212 unsigned int s_flags
= sb
->s_flags
;
213 int really_read_only
= bdev_read_only(nilfs
->ns_bdev
);
214 int valid_fs
= nilfs_valid_fs(nilfs
);
218 printk(KERN_WARNING
"NILFS warning: mounting unchecked fs\n");
219 if (s_flags
& MS_RDONLY
) {
220 printk(KERN_INFO
"NILFS: INFO: recovery "
221 "required for readonly filesystem.\n");
222 printk(KERN_INFO
"NILFS: write access will "
223 "be enabled during recovery.\n");
227 nilfs_init_recovery_info(&ri
);
229 err
= nilfs_search_super_root(nilfs
, &ri
);
231 struct nilfs_super_block
**sbp
= nilfs
->ns_sbp
;
237 if (!nilfs_valid_sb(sbp
[1])) {
239 "NILFS warning: unable to fall back to spare"
244 "NILFS: try rollback from an earlier position\n");
247 * restore super block with its spare and reconfigure
248 * relevant states of the nilfs object.
250 memcpy(sbp
[0], sbp
[1], nilfs
->ns_sbsize
);
251 nilfs
->ns_crc_seed
= le32_to_cpu(sbp
[0]->s_crc_seed
);
252 nilfs
->ns_sbwtime
= le64_to_cpu(sbp
[0]->s_wtime
);
254 /* verify consistency between two super blocks */
255 blocksize
= BLOCK_SIZE
<< le32_to_cpu(sbp
[0]->s_log_block_size
);
256 if (blocksize
!= nilfs
->ns_blocksize
) {
258 "NILFS warning: blocksize differs between "
259 "two super blocks (%d != %d)\n",
260 blocksize
, nilfs
->ns_blocksize
);
264 err
= nilfs_store_log_cursor(nilfs
, sbp
[0]);
268 /* drop clean flag to allow roll-forward and recovery */
269 nilfs
->ns_mount_state
&= ~NILFS_VALID_FS
;
272 err
= nilfs_search_super_root(nilfs
, &ri
);
277 err
= nilfs_load_super_root(nilfs
, sb
, ri
.ri_super_root
);
279 printk(KERN_ERR
"NILFS: error loading super root.\n");
286 if (s_flags
& MS_RDONLY
) {
289 if (nilfs_test_opt(nilfs
, NORECOVERY
)) {
290 printk(KERN_INFO
"NILFS: norecovery option specified. "
291 "skipping roll-forward recovery\n");
294 features
= le64_to_cpu(nilfs
->ns_sbp
[0]->s_feature_compat_ro
) &
295 ~NILFS_FEATURE_COMPAT_RO_SUPP
;
297 printk(KERN_ERR
"NILFS: couldn't proceed with "
298 "recovery because of unsupported optional "
300 (unsigned long long)features
);
304 if (really_read_only
) {
305 printk(KERN_ERR
"NILFS: write access "
306 "unavailable, cannot proceed.\n");
310 sb
->s_flags
&= ~MS_RDONLY
;
311 } else if (nilfs_test_opt(nilfs
, NORECOVERY
)) {
312 printk(KERN_ERR
"NILFS: recovery cancelled because norecovery "
313 "option was specified for a read/write mount\n");
318 err
= nilfs_salvage_orphan_logs(nilfs
, sb
, &ri
);
322 down_write(&nilfs
->ns_sem
);
323 nilfs
->ns_mount_state
|= NILFS_VALID_FS
; /* set "clean" flag */
324 err
= nilfs_cleanup_super(sb
);
325 up_write(&nilfs
->ns_sem
);
328 printk(KERN_ERR
"NILFS: failed to update super block. "
329 "recovery unfinished.\n");
332 printk(KERN_INFO
"NILFS: recovery complete.\n");
335 nilfs_clear_recovery_info(&ri
);
336 sb
->s_flags
= s_flags
;
340 printk(KERN_ERR
"NILFS: error searching super root.\n");
344 iput(nilfs
->ns_cpfile
);
345 iput(nilfs
->ns_sufile
);
349 nilfs_clear_recovery_info(&ri
);
350 sb
->s_flags
= s_flags
;
354 static unsigned long long nilfs_max_size(unsigned int blkbits
)
356 unsigned int max_bits
;
357 unsigned long long res
= MAX_LFS_FILESIZE
; /* page cache limit */
359 max_bits
= blkbits
+ NILFS_BMAP_KEY_BIT
; /* bmap size limit */
361 res
= min_t(unsigned long long, res
, (1ULL << max_bits
) - 1);
366 * nilfs_nrsvsegs - calculate the number of reserved segments
367 * @nilfs: nilfs object
368 * @nsegs: total number of segments
370 unsigned long nilfs_nrsvsegs(struct the_nilfs
*nilfs
, unsigned long nsegs
)
372 return max_t(unsigned long, NILFS_MIN_NRSVSEGS
,
373 DIV_ROUND_UP(nsegs
* nilfs
->ns_r_segments_percentage
,
377 void nilfs_set_nsegments(struct the_nilfs
*nilfs
, unsigned long nsegs
)
379 nilfs
->ns_nsegments
= nsegs
;
380 nilfs
->ns_nrsvsegs
= nilfs_nrsvsegs(nilfs
, nsegs
);
383 static int nilfs_store_disk_layout(struct the_nilfs
*nilfs
,
384 struct nilfs_super_block
*sbp
)
386 if (le32_to_cpu(sbp
->s_rev_level
) < NILFS_MIN_SUPP_REV
) {
387 printk(KERN_ERR
"NILFS: unsupported revision "
388 "(superblock rev.=%d.%d, current rev.=%d.%d). "
389 "Please check the version of mkfs.nilfs.\n",
390 le32_to_cpu(sbp
->s_rev_level
),
391 le16_to_cpu(sbp
->s_minor_rev_level
),
392 NILFS_CURRENT_REV
, NILFS_MINOR_REV
);
395 nilfs
->ns_sbsize
= le16_to_cpu(sbp
->s_bytes
);
396 if (nilfs
->ns_sbsize
> BLOCK_SIZE
)
399 nilfs
->ns_inode_size
= le16_to_cpu(sbp
->s_inode_size
);
400 if (nilfs
->ns_inode_size
> nilfs
->ns_blocksize
) {
401 printk(KERN_ERR
"NILFS: too large inode size: %d bytes.\n",
402 nilfs
->ns_inode_size
);
404 } else if (nilfs
->ns_inode_size
< NILFS_MIN_INODE_SIZE
) {
405 printk(KERN_ERR
"NILFS: too small inode size: %d bytes.\n",
406 nilfs
->ns_inode_size
);
410 nilfs
->ns_first_ino
= le32_to_cpu(sbp
->s_first_ino
);
412 nilfs
->ns_blocks_per_segment
= le32_to_cpu(sbp
->s_blocks_per_segment
);
413 if (nilfs
->ns_blocks_per_segment
< NILFS_SEG_MIN_BLOCKS
) {
414 printk(KERN_ERR
"NILFS: too short segment.\n");
418 nilfs
->ns_first_data_block
= le64_to_cpu(sbp
->s_first_data_block
);
419 nilfs
->ns_r_segments_percentage
=
420 le32_to_cpu(sbp
->s_r_segments_percentage
);
421 if (nilfs
->ns_r_segments_percentage
< 1 ||
422 nilfs
->ns_r_segments_percentage
> 99) {
423 printk(KERN_ERR
"NILFS: invalid reserved segments percentage.\n");
427 nilfs_set_nsegments(nilfs
, le64_to_cpu(sbp
->s_nsegments
));
428 nilfs
->ns_crc_seed
= le32_to_cpu(sbp
->s_crc_seed
);
432 static int nilfs_valid_sb(struct nilfs_super_block
*sbp
)
434 static unsigned char sum
[4];
435 const int sumoff
= offsetof(struct nilfs_super_block
, s_sum
);
439 if (!sbp
|| le16_to_cpu(sbp
->s_magic
) != NILFS_SUPER_MAGIC
)
441 bytes
= le16_to_cpu(sbp
->s_bytes
);
442 if (bytes
< sumoff
+ 4 || bytes
> BLOCK_SIZE
)
444 crc
= crc32_le(le32_to_cpu(sbp
->s_crc_seed
), (unsigned char *)sbp
,
446 crc
= crc32_le(crc
, sum
, 4);
447 crc
= crc32_le(crc
, (unsigned char *)sbp
+ sumoff
+ 4,
449 return crc
== le32_to_cpu(sbp
->s_sum
);
452 static int nilfs_sb2_bad_offset(struct nilfs_super_block
*sbp
, u64 offset
)
454 return offset
< ((le64_to_cpu(sbp
->s_nsegments
) *
455 le32_to_cpu(sbp
->s_blocks_per_segment
)) <<
456 (le32_to_cpu(sbp
->s_log_block_size
) + 10));
459 static void nilfs_release_super_block(struct the_nilfs
*nilfs
)
463 for (i
= 0; i
< 2; i
++) {
464 if (nilfs
->ns_sbp
[i
]) {
465 brelse(nilfs
->ns_sbh
[i
]);
466 nilfs
->ns_sbh
[i
] = NULL
;
467 nilfs
->ns_sbp
[i
] = NULL
;
472 void nilfs_fall_back_super_block(struct the_nilfs
*nilfs
)
474 brelse(nilfs
->ns_sbh
[0]);
475 nilfs
->ns_sbh
[0] = nilfs
->ns_sbh
[1];
476 nilfs
->ns_sbp
[0] = nilfs
->ns_sbp
[1];
477 nilfs
->ns_sbh
[1] = NULL
;
478 nilfs
->ns_sbp
[1] = NULL
;
481 void nilfs_swap_super_block(struct the_nilfs
*nilfs
)
483 struct buffer_head
*tsbh
= nilfs
->ns_sbh
[0];
484 struct nilfs_super_block
*tsbp
= nilfs
->ns_sbp
[0];
486 nilfs
->ns_sbh
[0] = nilfs
->ns_sbh
[1];
487 nilfs
->ns_sbp
[0] = nilfs
->ns_sbp
[1];
488 nilfs
->ns_sbh
[1] = tsbh
;
489 nilfs
->ns_sbp
[1] = tsbp
;
492 static int nilfs_load_super_block(struct the_nilfs
*nilfs
,
493 struct super_block
*sb
, int blocksize
,
494 struct nilfs_super_block
**sbpp
)
496 struct nilfs_super_block
**sbp
= nilfs
->ns_sbp
;
497 struct buffer_head
**sbh
= nilfs
->ns_sbh
;
498 u64 sb2off
= NILFS_SB2_OFFSET_BYTES(nilfs
->ns_bdev
->bd_inode
->i_size
);
499 int valid
[2], swp
= 0;
501 sbp
[0] = nilfs_read_super_block(sb
, NILFS_SB_OFFSET_BYTES
, blocksize
,
503 sbp
[1] = nilfs_read_super_block(sb
, sb2off
, blocksize
, &sbh
[1]);
507 printk(KERN_ERR
"NILFS: unable to read superblock\n");
511 "NILFS warning: unable to read primary superblock "
512 "(blocksize = %d)\n", blocksize
);
513 } else if (!sbp
[1]) {
515 "NILFS warning: unable to read secondary superblock "
516 "(blocksize = %d)\n", blocksize
);
520 * Compare two super blocks and set 1 in swp if the secondary
521 * super block is valid and newer. Otherwise, set 0 in swp.
523 valid
[0] = nilfs_valid_sb(sbp
[0]);
524 valid
[1] = nilfs_valid_sb(sbp
[1]);
525 swp
= valid
[1] && (!valid
[0] ||
526 le64_to_cpu(sbp
[1]->s_last_cno
) >
527 le64_to_cpu(sbp
[0]->s_last_cno
));
529 if (valid
[swp
] && nilfs_sb2_bad_offset(sbp
[swp
], sb2off
)) {
537 nilfs_release_super_block(nilfs
);
538 printk(KERN_ERR
"NILFS: Can't find nilfs on dev %s.\n",
544 printk(KERN_WARNING
"NILFS warning: broken superblock. "
545 "using spare superblock (blocksize = %d).\n", blocksize
);
547 nilfs_swap_super_block(nilfs
);
549 nilfs
->ns_sbwcount
= 0;
550 nilfs
->ns_sbwtime
= le64_to_cpu(sbp
[0]->s_wtime
);
551 nilfs
->ns_prot_seq
= le64_to_cpu(sbp
[valid
[1] & !swp
]->s_last_seq
);
557 * init_nilfs - initialize a NILFS instance.
558 * @nilfs: the_nilfs structure
560 * @data: mount options
562 * init_nilfs() performs common initialization per block device (e.g.
563 * reading the super block, getting disk layout information, initializing
564 * shared fields in the_nilfs).
566 * Return Value: On success, 0 is returned. On error, a negative error
569 int init_nilfs(struct the_nilfs
*nilfs
, struct super_block
*sb
, char *data
)
571 struct nilfs_super_block
*sbp
;
575 down_write(&nilfs
->ns_sem
);
577 blocksize
= sb_min_blocksize(sb
, NILFS_MIN_BLOCK_SIZE
);
579 printk(KERN_ERR
"NILFS: unable to set blocksize\n");
583 err
= nilfs_load_super_block(nilfs
, sb
, blocksize
, &sbp
);
587 err
= nilfs_store_magic_and_option(sb
, sbp
, data
);
591 err
= nilfs_check_feature_compatibility(sb
, sbp
);
595 blocksize
= BLOCK_SIZE
<< le32_to_cpu(sbp
->s_log_block_size
);
596 if (blocksize
< NILFS_MIN_BLOCK_SIZE
||
597 blocksize
> NILFS_MAX_BLOCK_SIZE
) {
598 printk(KERN_ERR
"NILFS: couldn't mount because of unsupported "
599 "filesystem blocksize %d\n", blocksize
);
603 if (sb
->s_blocksize
!= blocksize
) {
604 int hw_blocksize
= bdev_logical_block_size(sb
->s_bdev
);
606 if (blocksize
< hw_blocksize
) {
608 "NILFS: blocksize %d too small for device "
609 "(sector-size = %d).\n",
610 blocksize
, hw_blocksize
);
614 nilfs_release_super_block(nilfs
);
615 sb_set_blocksize(sb
, blocksize
);
617 err
= nilfs_load_super_block(nilfs
, sb
, blocksize
, &sbp
);
621 * Not to failed_sbh; sbh is released automatically
622 * when reloading fails.
625 nilfs
->ns_blocksize_bits
= sb
->s_blocksize_bits
;
626 nilfs
->ns_blocksize
= blocksize
;
628 get_random_bytes(&nilfs
->ns_next_generation
,
629 sizeof(nilfs
->ns_next_generation
));
631 err
= nilfs_store_disk_layout(nilfs
, sbp
);
635 sb
->s_maxbytes
= nilfs_max_size(sb
->s_blocksize_bits
);
637 nilfs
->ns_mount_state
= le16_to_cpu(sbp
->s_state
);
639 err
= nilfs_store_log_cursor(nilfs
, sbp
);
643 err
= nilfs_sysfs_create_device_group(sb
);
647 set_nilfs_init(nilfs
);
650 up_write(&nilfs
->ns_sem
);
654 nilfs_release_super_block(nilfs
);
658 int nilfs_discard_segments(struct the_nilfs
*nilfs
, __u64
*segnump
,
661 sector_t seg_start
, seg_end
;
662 sector_t start
= 0, nblocks
= 0;
663 unsigned int sects_per_block
;
667 sects_per_block
= (1 << nilfs
->ns_blocksize_bits
) /
668 bdev_logical_block_size(nilfs
->ns_bdev
);
669 for (sn
= segnump
; sn
< segnump
+ nsegs
; sn
++) {
670 nilfs_get_segment_range(nilfs
, *sn
, &seg_start
, &seg_end
);
674 nblocks
= seg_end
- seg_start
+ 1;
675 } else if (start
+ nblocks
== seg_start
) {
676 nblocks
+= seg_end
- seg_start
+ 1;
678 ret
= blkdev_issue_discard(nilfs
->ns_bdev
,
679 start
* sects_per_block
,
680 nblocks
* sects_per_block
,
688 ret
= blkdev_issue_discard(nilfs
->ns_bdev
,
689 start
* sects_per_block
,
690 nblocks
* sects_per_block
,
695 int nilfs_count_free_blocks(struct the_nilfs
*nilfs
, sector_t
*nblocks
)
697 unsigned long ncleansegs
;
699 down_read(&NILFS_MDT(nilfs
->ns_dat
)->mi_sem
);
700 ncleansegs
= nilfs_sufile_get_ncleansegs(nilfs
->ns_sufile
);
701 up_read(&NILFS_MDT(nilfs
->ns_dat
)->mi_sem
);
702 *nblocks
= (sector_t
)ncleansegs
* nilfs
->ns_blocks_per_segment
;
706 int nilfs_near_disk_full(struct the_nilfs
*nilfs
)
708 unsigned long ncleansegs
, nincsegs
;
710 ncleansegs
= nilfs_sufile_get_ncleansegs(nilfs
->ns_sufile
);
711 nincsegs
= atomic_read(&nilfs
->ns_ndirtyblks
) /
712 nilfs
->ns_blocks_per_segment
+ 1;
714 return ncleansegs
<= nilfs
->ns_nrsvsegs
+ nincsegs
;
717 struct nilfs_root
*nilfs_lookup_root(struct the_nilfs
*nilfs
, __u64 cno
)
720 struct nilfs_root
*root
;
722 spin_lock(&nilfs
->ns_cptree_lock
);
723 n
= nilfs
->ns_cptree
.rb_node
;
725 root
= rb_entry(n
, struct nilfs_root
, rb_node
);
727 if (cno
< root
->cno
) {
729 } else if (cno
> root
->cno
) {
732 atomic_inc(&root
->count
);
733 spin_unlock(&nilfs
->ns_cptree_lock
);
737 spin_unlock(&nilfs
->ns_cptree_lock
);
743 nilfs_find_or_create_root(struct the_nilfs
*nilfs
, __u64 cno
)
745 struct rb_node
**p
, *parent
;
746 struct nilfs_root
*root
, *new;
749 root
= nilfs_lookup_root(nilfs
, cno
);
753 new = kzalloc(sizeof(*root
), GFP_KERNEL
);
757 spin_lock(&nilfs
->ns_cptree_lock
);
759 p
= &nilfs
->ns_cptree
.rb_node
;
764 root
= rb_entry(parent
, struct nilfs_root
, rb_node
);
766 if (cno
< root
->cno
) {
768 } else if (cno
> root
->cno
) {
771 atomic_inc(&root
->count
);
772 spin_unlock(&nilfs
->ns_cptree_lock
);
781 atomic_set(&new->count
, 1);
782 atomic64_set(&new->inodes_count
, 0);
783 atomic64_set(&new->blocks_count
, 0);
785 rb_link_node(&new->rb_node
, parent
, p
);
786 rb_insert_color(&new->rb_node
, &nilfs
->ns_cptree
);
788 spin_unlock(&nilfs
->ns_cptree_lock
);
790 err
= nilfs_sysfs_create_snapshot_group(new);
799 void nilfs_put_root(struct nilfs_root
*root
)
801 if (atomic_dec_and_test(&root
->count
)) {
802 struct the_nilfs
*nilfs
= root
->nilfs
;
804 nilfs_sysfs_delete_snapshot_group(root
);
806 spin_lock(&nilfs
->ns_cptree_lock
);
807 rb_erase(&root
->rb_node
, &nilfs
->ns_cptree
);
808 spin_unlock(&nilfs
->ns_cptree_lock
);