1 // SPDX-License-Identifier: GPL-2.0+
3 * the_nilfs.c - the_nilfs shared structure.
5 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
7 * Written by Ryusuke Konishi.
11 #include <linux/buffer_head.h>
12 #include <linux/slab.h>
13 #include <linux/blkdev.h>
14 #include <linux/backing-dev.h>
15 #include <linux/random.h>
16 #include <linux/log2.h>
17 #include <linux/crc32.h>
27 static int nilfs_valid_sb(struct nilfs_super_block *sbp);
29 void nilfs_set_last_segment(struct the_nilfs *nilfs,
30 sector_t start_blocknr, u64 seq, __u64 cno)
32 spin_lock(&nilfs->ns_last_segment_lock);
33 nilfs->ns_last_pseg = start_blocknr;
34 nilfs->ns_last_seq = seq;
35 nilfs->ns_last_cno = cno;
37 if (!nilfs_sb_dirty(nilfs)) {
38 if (nilfs->ns_prev_seq == nilfs->ns_last_seq)
41 set_nilfs_sb_dirty(nilfs);
43 nilfs->ns_prev_seq = nilfs->ns_last_seq;
46 spin_unlock(&nilfs->ns_last_segment_lock);
50 * alloc_nilfs - allocate a nilfs object
51 * @sb: super block instance
53 * Return Value: On success, pointer to the_nilfs is returned.
54 * On error, NULL is returned.
56 struct the_nilfs *alloc_nilfs(struct super_block *sb)
58 struct the_nilfs *nilfs;
60 nilfs = kzalloc(sizeof(*nilfs), GFP_KERNEL);
65 nilfs->ns_bdev = sb->s_bdev;
66 atomic_set(&nilfs->ns_ndirtyblks, 0);
67 init_rwsem(&nilfs->ns_sem);
68 mutex_init(&nilfs->ns_snapshot_mount_mutex);
69 INIT_LIST_HEAD(&nilfs->ns_dirty_files);
70 INIT_LIST_HEAD(&nilfs->ns_gc_inodes);
71 spin_lock_init(&nilfs->ns_inode_lock);
72 spin_lock_init(&nilfs->ns_next_gen_lock);
73 spin_lock_init(&nilfs->ns_last_segment_lock);
74 nilfs->ns_cptree = RB_ROOT;
75 spin_lock_init(&nilfs->ns_cptree_lock);
76 init_rwsem(&nilfs->ns_segctor_sem);
77 nilfs->ns_sb_update_freq = NILFS_SB_FREQ;
83 * destroy_nilfs - destroy nilfs object
84 * @nilfs: nilfs object to be released
86 void destroy_nilfs(struct the_nilfs *nilfs)
89 if (nilfs_init(nilfs)) {
90 brelse(nilfs->ns_sbh[0]);
91 brelse(nilfs->ns_sbh[1]);
96 static int nilfs_load_super_root(struct the_nilfs *nilfs,
97 struct super_block *sb, sector_t sr_block)
99 struct buffer_head *bh_sr;
100 struct nilfs_super_root *raw_sr;
101 struct nilfs_super_block **sbp = nilfs->ns_sbp;
102 struct nilfs_inode *rawi;
103 unsigned int dat_entry_size, segment_usage_size, checkpoint_size;
104 unsigned int inode_size;
107 err = nilfs_read_super_root_block(nilfs, sr_block, &bh_sr, 1);
111 down_read(&nilfs->ns_sem);
112 dat_entry_size = le16_to_cpu(sbp[0]->s_dat_entry_size);
113 checkpoint_size = le16_to_cpu(sbp[0]->s_checkpoint_size);
114 segment_usage_size = le16_to_cpu(sbp[0]->s_segment_usage_size);
115 up_read(&nilfs->ns_sem);
117 inode_size = nilfs->ns_inode_size;
119 rawi = (void *)bh_sr->b_data + NILFS_SR_DAT_OFFSET(inode_size);
120 err = nilfs_dat_read(sb, dat_entry_size, rawi, &nilfs->ns_dat);
124 rawi = (void *)bh_sr->b_data + NILFS_SR_CPFILE_OFFSET(inode_size);
125 err = nilfs_cpfile_read(sb, checkpoint_size, rawi, &nilfs->ns_cpfile);
129 rawi = (void *)bh_sr->b_data + NILFS_SR_SUFILE_OFFSET(inode_size);
130 err = nilfs_sufile_read(sb, segment_usage_size, rawi,
135 raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
136 nilfs->ns_nongc_ctime = le64_to_cpu(raw_sr->sr_nongc_ctime);
143 iput(nilfs->ns_cpfile);
150 static void nilfs_init_recovery_info(struct nilfs_recovery_info *ri)
152 memset(ri, 0, sizeof(*ri));
153 INIT_LIST_HEAD(&ri->ri_used_segments);
156 static void nilfs_clear_recovery_info(struct nilfs_recovery_info *ri)
158 nilfs_dispose_segment_list(&ri->ri_used_segments);
162 * nilfs_store_log_cursor - load log cursor from a super block
163 * @nilfs: nilfs object
164 * @sbp: buffer storing super block to be read
166 * nilfs_store_log_cursor() reads the last position of the log
167 * containing a super root from a given super block, and initializes
168 * relevant information on the nilfs object preparatory for log
169 * scanning and recovery.
171 static int nilfs_store_log_cursor(struct the_nilfs *nilfs,
172 struct nilfs_super_block *sbp)
176 nilfs->ns_last_pseg = le64_to_cpu(sbp->s_last_pseg);
177 nilfs->ns_last_cno = le64_to_cpu(sbp->s_last_cno);
178 nilfs->ns_last_seq = le64_to_cpu(sbp->s_last_seq);
180 nilfs->ns_prev_seq = nilfs->ns_last_seq;
181 nilfs->ns_seg_seq = nilfs->ns_last_seq;
183 nilfs_get_segnum_of_block(nilfs, nilfs->ns_last_pseg);
184 nilfs->ns_cno = nilfs->ns_last_cno + 1;
185 if (nilfs->ns_segnum >= nilfs->ns_nsegments) {
186 nilfs_msg(nilfs->ns_sb, KERN_ERR,
187 "pointed segment number is out of range: segnum=%llu, nsegments=%lu",
188 (unsigned long long)nilfs->ns_segnum,
189 nilfs->ns_nsegments);
196 * load_nilfs - load and recover the nilfs
197 * @nilfs: the_nilfs structure to be released
198 * @sb: super block isntance used to recover past segment
200 * load_nilfs() searches and load the latest super root,
201 * attaches the last segment, and does recovery if needed.
202 * The caller must call this exclusively for simultaneous mounts.
204 int load_nilfs(struct the_nilfs *nilfs, struct super_block *sb)
206 struct nilfs_recovery_info ri;
207 unsigned int s_flags = sb->s_flags;
208 int really_read_only = bdev_read_only(nilfs->ns_bdev);
209 int valid_fs = nilfs_valid_fs(nilfs);
213 nilfs_msg(sb, KERN_WARNING, "mounting unchecked fs");
214 if (s_flags & SB_RDONLY) {
215 nilfs_msg(sb, KERN_INFO,
216 "recovery required for readonly filesystem");
217 nilfs_msg(sb, KERN_INFO,
218 "write access will be enabled during recovery");
222 nilfs_init_recovery_info(&ri);
224 err = nilfs_search_super_root(nilfs, &ri);
226 struct nilfs_super_block **sbp = nilfs->ns_sbp;
232 if (!nilfs_valid_sb(sbp[1])) {
233 nilfs_msg(sb, KERN_WARNING,
234 "unable to fall back to spare super block");
237 nilfs_msg(sb, KERN_INFO,
238 "trying rollback from an earlier position");
241 * restore super block with its spare and reconfigure
242 * relevant states of the nilfs object.
244 memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
245 nilfs->ns_crc_seed = le32_to_cpu(sbp[0]->s_crc_seed);
246 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime);
248 /* verify consistency between two super blocks */
249 blocksize = BLOCK_SIZE << le32_to_cpu(sbp[0]->s_log_block_size);
250 if (blocksize != nilfs->ns_blocksize) {
251 nilfs_msg(sb, KERN_WARNING,
252 "blocksize differs between two super blocks (%d != %d)",
253 blocksize, nilfs->ns_blocksize);
257 err = nilfs_store_log_cursor(nilfs, sbp[0]);
261 /* drop clean flag to allow roll-forward and recovery */
262 nilfs->ns_mount_state &= ~NILFS_VALID_FS;
265 err = nilfs_search_super_root(nilfs, &ri);
270 err = nilfs_load_super_root(nilfs, sb, ri.ri_super_root);
272 nilfs_msg(sb, KERN_ERR, "error %d while loading super root",
277 err = nilfs_sysfs_create_device_group(sb);
284 if (s_flags & SB_RDONLY) {
287 if (nilfs_test_opt(nilfs, NORECOVERY)) {
288 nilfs_msg(sb, KERN_INFO,
289 "norecovery option specified, skipping roll-forward recovery");
292 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
293 ~NILFS_FEATURE_COMPAT_RO_SUPP;
295 nilfs_msg(sb, KERN_ERR,
296 "couldn't proceed with recovery because of unsupported optional features (%llx)",
297 (unsigned long long)features);
301 if (really_read_only) {
302 nilfs_msg(sb, KERN_ERR,
303 "write access unavailable, cannot proceed");
307 sb->s_flags &= ~SB_RDONLY;
308 } else if (nilfs_test_opt(nilfs, NORECOVERY)) {
309 nilfs_msg(sb, KERN_ERR,
310 "recovery cancelled because norecovery option was specified for a read/write mount");
315 err = nilfs_salvage_orphan_logs(nilfs, sb, &ri);
319 down_write(&nilfs->ns_sem);
320 nilfs->ns_mount_state |= NILFS_VALID_FS; /* set "clean" flag */
321 err = nilfs_cleanup_super(sb);
322 up_write(&nilfs->ns_sem);
325 nilfs_msg(sb, KERN_ERR,
326 "error %d updating super block. recovery unfinished.",
330 nilfs_msg(sb, KERN_INFO, "recovery complete");
333 nilfs_clear_recovery_info(&ri);
334 sb->s_flags = s_flags;
338 nilfs_msg(sb, KERN_ERR, "error %d while searching super root", err);
342 nilfs_sysfs_delete_device_group(nilfs);
345 iput(nilfs->ns_cpfile);
346 iput(nilfs->ns_sufile);
350 nilfs_clear_recovery_info(&ri);
351 sb->s_flags = s_flags;
355 static unsigned long long nilfs_max_size(unsigned int blkbits)
357 unsigned int max_bits;
358 unsigned long long res = MAX_LFS_FILESIZE; /* page cache limit */
360 max_bits = blkbits + NILFS_BMAP_KEY_BIT; /* bmap size limit */
362 res = min_t(unsigned long long, res, (1ULL << max_bits) - 1);
367 * nilfs_nrsvsegs - calculate the number of reserved segments
368 * @nilfs: nilfs object
369 * @nsegs: total number of segments
371 unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs)
373 return max_t(unsigned long, NILFS_MIN_NRSVSEGS,
374 DIV_ROUND_UP(nsegs * nilfs->ns_r_segments_percentage,
378 void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs)
380 nilfs->ns_nsegments = nsegs;
381 nilfs->ns_nrsvsegs = nilfs_nrsvsegs(nilfs, nsegs);
384 static int nilfs_store_disk_layout(struct the_nilfs *nilfs,
385 struct nilfs_super_block *sbp)
387 if (le32_to_cpu(sbp->s_rev_level) < NILFS_MIN_SUPP_REV) {
388 nilfs_msg(nilfs->ns_sb, KERN_ERR,
389 "unsupported revision (superblock rev.=%d.%d, current rev.=%d.%d). Please check the version of mkfs.nilfs(2).",
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 nilfs_msg(nilfs->ns_sb, KERN_ERR,
402 "too large inode size: %d bytes",
403 nilfs->ns_inode_size);
405 } else if (nilfs->ns_inode_size < NILFS_MIN_INODE_SIZE) {
406 nilfs_msg(nilfs->ns_sb, KERN_ERR,
407 "too small inode size: %d bytes",
408 nilfs->ns_inode_size);
412 nilfs->ns_first_ino = le32_to_cpu(sbp->s_first_ino);
414 nilfs->ns_blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment);
415 if (nilfs->ns_blocks_per_segment < NILFS_SEG_MIN_BLOCKS) {
416 nilfs_msg(nilfs->ns_sb, KERN_ERR,
417 "too short segment: %lu blocks",
418 nilfs->ns_blocks_per_segment);
422 nilfs->ns_first_data_block = le64_to_cpu(sbp->s_first_data_block);
423 nilfs->ns_r_segments_percentage =
424 le32_to_cpu(sbp->s_r_segments_percentage);
425 if (nilfs->ns_r_segments_percentage < 1 ||
426 nilfs->ns_r_segments_percentage > 99) {
427 nilfs_msg(nilfs->ns_sb, KERN_ERR,
428 "invalid reserved segments percentage: %lu",
429 nilfs->ns_r_segments_percentage);
433 nilfs_set_nsegments(nilfs, le64_to_cpu(sbp->s_nsegments));
434 nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed);
438 static int nilfs_valid_sb(struct nilfs_super_block *sbp)
440 static unsigned char sum[4];
441 const int sumoff = offsetof(struct nilfs_super_block, s_sum);
445 if (!sbp || le16_to_cpu(sbp->s_magic) != NILFS_SUPER_MAGIC)
447 bytes = le16_to_cpu(sbp->s_bytes);
448 if (bytes < sumoff + 4 || bytes > BLOCK_SIZE)
450 crc = crc32_le(le32_to_cpu(sbp->s_crc_seed), (unsigned char *)sbp,
452 crc = crc32_le(crc, sum, 4);
453 crc = crc32_le(crc, (unsigned char *)sbp + sumoff + 4,
455 return crc == le32_to_cpu(sbp->s_sum);
459 * nilfs_sb2_bad_offset - check the location of the second superblock
460 * @sbp: superblock raw data buffer
461 * @offset: byte offset of second superblock calculated from device size
463 * nilfs_sb2_bad_offset() checks if the position on the second
464 * superblock is valid or not based on the filesystem parameters
465 * stored in @sbp. If @offset points to a location within the segment
466 * area, or if the parameters themselves are not normal, it is
467 * determined to be invalid.
469 * Return Value: true if invalid, false if valid.
471 static bool nilfs_sb2_bad_offset(struct nilfs_super_block *sbp, u64 offset)
473 unsigned int shift_bits = le32_to_cpu(sbp->s_log_block_size);
474 u32 blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment);
475 u64 nsegments = le64_to_cpu(sbp->s_nsegments);
478 if (blocks_per_segment < NILFS_SEG_MIN_BLOCKS ||
479 shift_bits > ilog2(NILFS_MAX_BLOCK_SIZE) - BLOCK_SIZE_BITS)
482 index = offset >> (shift_bits + BLOCK_SIZE_BITS);
483 do_div(index, blocks_per_segment);
484 return index < nsegments;
487 static void nilfs_release_super_block(struct the_nilfs *nilfs)
491 for (i = 0; i < 2; i++) {
492 if (nilfs->ns_sbp[i]) {
493 brelse(nilfs->ns_sbh[i]);
494 nilfs->ns_sbh[i] = NULL;
495 nilfs->ns_sbp[i] = NULL;
500 void nilfs_fall_back_super_block(struct the_nilfs *nilfs)
502 brelse(nilfs->ns_sbh[0]);
503 nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
504 nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
505 nilfs->ns_sbh[1] = NULL;
506 nilfs->ns_sbp[1] = NULL;
509 void nilfs_swap_super_block(struct the_nilfs *nilfs)
511 struct buffer_head *tsbh = nilfs->ns_sbh[0];
512 struct nilfs_super_block *tsbp = nilfs->ns_sbp[0];
514 nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
515 nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
516 nilfs->ns_sbh[1] = tsbh;
517 nilfs->ns_sbp[1] = tsbp;
520 static int nilfs_load_super_block(struct the_nilfs *nilfs,
521 struct super_block *sb, int blocksize,
522 struct nilfs_super_block **sbpp)
524 struct nilfs_super_block **sbp = nilfs->ns_sbp;
525 struct buffer_head **sbh = nilfs->ns_sbh;
526 u64 sb2off, devsize = nilfs->ns_bdev->bd_inode->i_size;
527 int valid[2], swp = 0;
529 if (devsize < NILFS_SEG_MIN_BLOCKS * NILFS_MIN_BLOCK_SIZE + 4096) {
530 nilfs_msg(sb, KERN_ERR, "device size too small");
533 sb2off = NILFS_SB2_OFFSET_BYTES(devsize);
535 sbp[0] = nilfs_read_super_block(sb, NILFS_SB_OFFSET_BYTES, blocksize,
537 sbp[1] = nilfs_read_super_block(sb, sb2off, blocksize, &sbh[1]);
541 nilfs_msg(sb, KERN_ERR, "unable to read superblock");
544 nilfs_msg(sb, KERN_WARNING,
545 "unable to read primary superblock (blocksize = %d)",
547 } else if (!sbp[1]) {
548 nilfs_msg(sb, KERN_WARNING,
549 "unable to read secondary superblock (blocksize = %d)",
554 * Compare two super blocks and set 1 in swp if the secondary
555 * super block is valid and newer. Otherwise, set 0 in swp.
557 valid[0] = nilfs_valid_sb(sbp[0]);
558 valid[1] = nilfs_valid_sb(sbp[1]);
559 swp = valid[1] && (!valid[0] ||
560 le64_to_cpu(sbp[1]->s_last_cno) >
561 le64_to_cpu(sbp[0]->s_last_cno));
563 if (valid[swp] && nilfs_sb2_bad_offset(sbp[swp], sb2off)) {
571 nilfs_release_super_block(nilfs);
572 nilfs_msg(sb, KERN_ERR, "couldn't find nilfs on the device");
577 nilfs_msg(sb, KERN_WARNING,
578 "broken superblock, retrying with spare superblock (blocksize = %d)",
581 nilfs_swap_super_block(nilfs);
583 nilfs->ns_sbwcount = 0;
584 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime);
585 nilfs->ns_prot_seq = le64_to_cpu(sbp[valid[1] & !swp]->s_last_seq);
591 * init_nilfs - initialize a NILFS instance.
592 * @nilfs: the_nilfs structure
594 * @data: mount options
596 * init_nilfs() performs common initialization per block device (e.g.
597 * reading the super block, getting disk layout information, initializing
598 * shared fields in the_nilfs).
600 * Return Value: On success, 0 is returned. On error, a negative error
603 int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data)
605 struct nilfs_super_block *sbp;
609 down_write(&nilfs->ns_sem);
611 blocksize = sb_min_blocksize(sb, NILFS_MIN_BLOCK_SIZE);
613 nilfs_msg(sb, KERN_ERR, "unable to set blocksize");
617 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
621 err = nilfs_store_magic_and_option(sb, sbp, data);
625 err = nilfs_check_feature_compatibility(sb, sbp);
629 blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size);
630 if (blocksize < NILFS_MIN_BLOCK_SIZE ||
631 blocksize > NILFS_MAX_BLOCK_SIZE) {
632 nilfs_msg(sb, KERN_ERR,
633 "couldn't mount because of unsupported filesystem blocksize %d",
638 if (sb->s_blocksize != blocksize) {
639 int hw_blocksize = bdev_logical_block_size(sb->s_bdev);
641 if (blocksize < hw_blocksize) {
642 nilfs_msg(sb, KERN_ERR,
643 "blocksize %d too small for device (sector-size = %d)",
644 blocksize, hw_blocksize);
648 nilfs_release_super_block(nilfs);
649 sb_set_blocksize(sb, blocksize);
651 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
655 * Not to failed_sbh; sbh is released automatically
656 * when reloading fails.
659 nilfs->ns_blocksize_bits = sb->s_blocksize_bits;
660 nilfs->ns_blocksize = blocksize;
662 get_random_bytes(&nilfs->ns_next_generation,
663 sizeof(nilfs->ns_next_generation));
665 err = nilfs_store_disk_layout(nilfs, sbp);
669 sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits);
671 nilfs->ns_mount_state = le16_to_cpu(sbp->s_state);
673 err = nilfs_store_log_cursor(nilfs, sbp);
677 set_nilfs_init(nilfs);
680 up_write(&nilfs->ns_sem);
684 nilfs_release_super_block(nilfs);
688 int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump,
691 sector_t seg_start, seg_end;
692 sector_t start = 0, nblocks = 0;
693 unsigned int sects_per_block;
697 sects_per_block = (1 << nilfs->ns_blocksize_bits) /
698 bdev_logical_block_size(nilfs->ns_bdev);
699 for (sn = segnump; sn < segnump + nsegs; sn++) {
700 nilfs_get_segment_range(nilfs, *sn, &seg_start, &seg_end);
704 nblocks = seg_end - seg_start + 1;
705 } else if (start + nblocks == seg_start) {
706 nblocks += seg_end - seg_start + 1;
708 ret = blkdev_issue_discard(nilfs->ns_bdev,
709 start * sects_per_block,
710 nblocks * sects_per_block,
718 ret = blkdev_issue_discard(nilfs->ns_bdev,
719 start * sects_per_block,
720 nblocks * sects_per_block,
725 int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks)
727 unsigned long ncleansegs;
729 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
730 *nblocks = (sector_t)ncleansegs * nilfs->ns_blocks_per_segment;
734 int nilfs_near_disk_full(struct the_nilfs *nilfs)
736 unsigned long ncleansegs, nincsegs;
738 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
739 nincsegs = atomic_read(&nilfs->ns_ndirtyblks) /
740 nilfs->ns_blocks_per_segment + 1;
742 return ncleansegs <= nilfs->ns_nrsvsegs + nincsegs;
745 struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno)
748 struct nilfs_root *root;
750 spin_lock(&nilfs->ns_cptree_lock);
751 n = nilfs->ns_cptree.rb_node;
753 root = rb_entry(n, struct nilfs_root, rb_node);
755 if (cno < root->cno) {
757 } else if (cno > root->cno) {
760 refcount_inc(&root->count);
761 spin_unlock(&nilfs->ns_cptree_lock);
765 spin_unlock(&nilfs->ns_cptree_lock);
771 nilfs_find_or_create_root(struct the_nilfs *nilfs, __u64 cno)
773 struct rb_node **p, *parent;
774 struct nilfs_root *root, *new;
777 root = nilfs_lookup_root(nilfs, cno);
781 new = kzalloc(sizeof(*root), GFP_KERNEL);
785 spin_lock(&nilfs->ns_cptree_lock);
787 p = &nilfs->ns_cptree.rb_node;
792 root = rb_entry(parent, struct nilfs_root, rb_node);
794 if (cno < root->cno) {
796 } else if (cno > root->cno) {
799 refcount_inc(&root->count);
800 spin_unlock(&nilfs->ns_cptree_lock);
809 refcount_set(&new->count, 1);
810 atomic64_set(&new->inodes_count, 0);
811 atomic64_set(&new->blocks_count, 0);
813 rb_link_node(&new->rb_node, parent, p);
814 rb_insert_color(&new->rb_node, &nilfs->ns_cptree);
816 spin_unlock(&nilfs->ns_cptree_lock);
818 err = nilfs_sysfs_create_snapshot_group(new);
827 void nilfs_put_root(struct nilfs_root *root)
829 struct the_nilfs *nilfs = root->nilfs;
831 if (refcount_dec_and_lock(&root->count, &nilfs->ns_cptree_lock)) {
832 rb_erase(&root->rb_node, &nilfs->ns_cptree);
833 spin_unlock(&nilfs->ns_cptree_lock);
835 nilfs_sysfs_delete_snapshot_group(root);