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,
379 * nilfs_max_segment_count - calculate the maximum number of segments
380 * @nilfs: nilfs object
382 static u64 nilfs_max_segment_count(struct the_nilfs *nilfs)
384 u64 max_count = U64_MAX;
386 do_div(max_count, nilfs->ns_blocks_per_segment);
387 return min_t(u64, max_count, ULONG_MAX);
390 void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs)
392 nilfs->ns_nsegments = nsegs;
393 nilfs->ns_nrsvsegs = nilfs_nrsvsegs(nilfs, nsegs);
396 static int nilfs_store_disk_layout(struct the_nilfs *nilfs,
397 struct nilfs_super_block *sbp)
399 u64 nsegments, nblocks;
401 if (le32_to_cpu(sbp->s_rev_level) < NILFS_MIN_SUPP_REV) {
402 nilfs_msg(nilfs->ns_sb, KERN_ERR,
403 "unsupported revision (superblock rev.=%d.%d, current rev.=%d.%d). Please check the version of mkfs.nilfs(2).",
404 le32_to_cpu(sbp->s_rev_level),
405 le16_to_cpu(sbp->s_minor_rev_level),
406 NILFS_CURRENT_REV, NILFS_MINOR_REV);
409 nilfs->ns_sbsize = le16_to_cpu(sbp->s_bytes);
410 if (nilfs->ns_sbsize > BLOCK_SIZE)
413 nilfs->ns_inode_size = le16_to_cpu(sbp->s_inode_size);
414 if (nilfs->ns_inode_size > nilfs->ns_blocksize) {
415 nilfs_msg(nilfs->ns_sb, KERN_ERR,
416 "too large inode size: %d bytes",
417 nilfs->ns_inode_size);
419 } else if (nilfs->ns_inode_size < NILFS_MIN_INODE_SIZE) {
420 nilfs_msg(nilfs->ns_sb, KERN_ERR,
421 "too small inode size: %d bytes",
422 nilfs->ns_inode_size);
426 nilfs->ns_first_ino = le32_to_cpu(sbp->s_first_ino);
428 nilfs->ns_blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment);
429 if (nilfs->ns_blocks_per_segment < NILFS_SEG_MIN_BLOCKS) {
430 nilfs_msg(nilfs->ns_sb, KERN_ERR,
431 "too short segment: %lu blocks",
432 nilfs->ns_blocks_per_segment);
436 nilfs->ns_first_data_block = le64_to_cpu(sbp->s_first_data_block);
437 nilfs->ns_r_segments_percentage =
438 le32_to_cpu(sbp->s_r_segments_percentage);
439 if (nilfs->ns_r_segments_percentage < 1 ||
440 nilfs->ns_r_segments_percentage > 99) {
441 nilfs_msg(nilfs->ns_sb, KERN_ERR,
442 "invalid reserved segments percentage: %lu",
443 nilfs->ns_r_segments_percentage);
447 nsegments = le64_to_cpu(sbp->s_nsegments);
448 if (nsegments > nilfs_max_segment_count(nilfs)) {
449 nilfs_msg(nilfs->ns_sb, KERN_ERR,
450 "segment count %llu exceeds upper limit (%llu segments)",
451 (unsigned long long)nsegments,
452 (unsigned long long)nilfs_max_segment_count(nilfs));
456 nblocks = (u64)i_size_read(nilfs->ns_sb->s_bdev->bd_inode) >>
457 nilfs->ns_sb->s_blocksize_bits;
459 u64 min_block_count = nsegments * nilfs->ns_blocks_per_segment;
461 * To avoid failing to mount early device images without a
462 * second superblock, exclude that block count from the
463 * "min_block_count" calculation.
466 if (nblocks < min_block_count) {
467 nilfs_msg(nilfs->ns_sb, KERN_ERR,
468 "total number of segment blocks %llu exceeds device size (%llu blocks)",
469 (unsigned long long)min_block_count,
470 (unsigned long long)nblocks);
475 nilfs_set_nsegments(nilfs, nsegments);
476 nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed);
480 static int nilfs_valid_sb(struct nilfs_super_block *sbp)
482 static unsigned char sum[4];
483 const int sumoff = offsetof(struct nilfs_super_block, s_sum);
487 if (!sbp || le16_to_cpu(sbp->s_magic) != NILFS_SUPER_MAGIC)
489 bytes = le16_to_cpu(sbp->s_bytes);
490 if (bytes < sumoff + 4 || bytes > BLOCK_SIZE)
492 crc = crc32_le(le32_to_cpu(sbp->s_crc_seed), (unsigned char *)sbp,
494 crc = crc32_le(crc, sum, 4);
495 crc = crc32_le(crc, (unsigned char *)sbp + sumoff + 4,
497 return crc == le32_to_cpu(sbp->s_sum);
501 * nilfs_sb2_bad_offset - check the location of the second superblock
502 * @sbp: superblock raw data buffer
503 * @offset: byte offset of second superblock calculated from device size
505 * nilfs_sb2_bad_offset() checks if the position on the second
506 * superblock is valid or not based on the filesystem parameters
507 * stored in @sbp. If @offset points to a location within the segment
508 * area, or if the parameters themselves are not normal, it is
509 * determined to be invalid.
511 * Return Value: true if invalid, false if valid.
513 static bool nilfs_sb2_bad_offset(struct nilfs_super_block *sbp, u64 offset)
515 unsigned int shift_bits = le32_to_cpu(sbp->s_log_block_size);
516 u32 blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment);
517 u64 nsegments = le64_to_cpu(sbp->s_nsegments);
520 if (blocks_per_segment < NILFS_SEG_MIN_BLOCKS ||
521 shift_bits > ilog2(NILFS_MAX_BLOCK_SIZE) - BLOCK_SIZE_BITS)
524 index = offset >> (shift_bits + BLOCK_SIZE_BITS);
525 do_div(index, blocks_per_segment);
526 return index < nsegments;
529 static void nilfs_release_super_block(struct the_nilfs *nilfs)
533 for (i = 0; i < 2; i++) {
534 if (nilfs->ns_sbp[i]) {
535 brelse(nilfs->ns_sbh[i]);
536 nilfs->ns_sbh[i] = NULL;
537 nilfs->ns_sbp[i] = NULL;
542 void nilfs_fall_back_super_block(struct the_nilfs *nilfs)
544 brelse(nilfs->ns_sbh[0]);
545 nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
546 nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
547 nilfs->ns_sbh[1] = NULL;
548 nilfs->ns_sbp[1] = NULL;
551 void nilfs_swap_super_block(struct the_nilfs *nilfs)
553 struct buffer_head *tsbh = nilfs->ns_sbh[0];
554 struct nilfs_super_block *tsbp = nilfs->ns_sbp[0];
556 nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
557 nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
558 nilfs->ns_sbh[1] = tsbh;
559 nilfs->ns_sbp[1] = tsbp;
562 static int nilfs_load_super_block(struct the_nilfs *nilfs,
563 struct super_block *sb, int blocksize,
564 struct nilfs_super_block **sbpp)
566 struct nilfs_super_block **sbp = nilfs->ns_sbp;
567 struct buffer_head **sbh = nilfs->ns_sbh;
568 u64 sb2off, devsize = nilfs->ns_bdev->bd_inode->i_size;
569 int valid[2], swp = 0;
571 if (devsize < NILFS_SEG_MIN_BLOCKS * NILFS_MIN_BLOCK_SIZE + 4096) {
572 nilfs_msg(sb, KERN_ERR, "device size too small");
575 sb2off = NILFS_SB2_OFFSET_BYTES(devsize);
577 sbp[0] = nilfs_read_super_block(sb, NILFS_SB_OFFSET_BYTES, blocksize,
579 sbp[1] = nilfs_read_super_block(sb, sb2off, blocksize, &sbh[1]);
583 nilfs_msg(sb, KERN_ERR, "unable to read superblock");
586 nilfs_msg(sb, KERN_WARNING,
587 "unable to read primary superblock (blocksize = %d)",
589 } else if (!sbp[1]) {
590 nilfs_msg(sb, KERN_WARNING,
591 "unable to read secondary superblock (blocksize = %d)",
596 * Compare two super blocks and set 1 in swp if the secondary
597 * super block is valid and newer. Otherwise, set 0 in swp.
599 valid[0] = nilfs_valid_sb(sbp[0]);
600 valid[1] = nilfs_valid_sb(sbp[1]);
601 swp = valid[1] && (!valid[0] ||
602 le64_to_cpu(sbp[1]->s_last_cno) >
603 le64_to_cpu(sbp[0]->s_last_cno));
605 if (valid[swp] && nilfs_sb2_bad_offset(sbp[swp], sb2off)) {
613 nilfs_release_super_block(nilfs);
614 nilfs_msg(sb, KERN_ERR, "couldn't find nilfs on the device");
619 nilfs_msg(sb, KERN_WARNING,
620 "broken superblock, retrying with spare superblock (blocksize = %d)",
623 nilfs_swap_super_block(nilfs);
625 nilfs->ns_sbwcount = 0;
626 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime);
627 nilfs->ns_prot_seq = le64_to_cpu(sbp[valid[1] & !swp]->s_last_seq);
633 * init_nilfs - initialize a NILFS instance.
634 * @nilfs: the_nilfs structure
636 * @data: mount options
638 * init_nilfs() performs common initialization per block device (e.g.
639 * reading the super block, getting disk layout information, initializing
640 * shared fields in the_nilfs).
642 * Return Value: On success, 0 is returned. On error, a negative error
645 int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data)
647 struct nilfs_super_block *sbp;
651 down_write(&nilfs->ns_sem);
653 blocksize = sb_min_blocksize(sb, NILFS_MIN_BLOCK_SIZE);
655 nilfs_msg(sb, KERN_ERR, "unable to set blocksize");
659 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
663 err = nilfs_store_magic_and_option(sb, sbp, data);
667 err = nilfs_check_feature_compatibility(sb, sbp);
671 blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size);
672 if (blocksize < NILFS_MIN_BLOCK_SIZE ||
673 blocksize > NILFS_MAX_BLOCK_SIZE) {
674 nilfs_msg(sb, KERN_ERR,
675 "couldn't mount because of unsupported filesystem blocksize %d",
680 if (sb->s_blocksize != blocksize) {
681 int hw_blocksize = bdev_logical_block_size(sb->s_bdev);
683 if (blocksize < hw_blocksize) {
684 nilfs_msg(sb, KERN_ERR,
685 "blocksize %d too small for device (sector-size = %d)",
686 blocksize, hw_blocksize);
690 nilfs_release_super_block(nilfs);
691 sb_set_blocksize(sb, blocksize);
693 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
697 * Not to failed_sbh; sbh is released automatically
698 * when reloading fails.
701 nilfs->ns_blocksize_bits = sb->s_blocksize_bits;
702 nilfs->ns_blocksize = blocksize;
704 get_random_bytes(&nilfs->ns_next_generation,
705 sizeof(nilfs->ns_next_generation));
707 err = nilfs_store_disk_layout(nilfs, sbp);
711 sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits);
713 nilfs->ns_mount_state = le16_to_cpu(sbp->s_state);
715 err = nilfs_store_log_cursor(nilfs, sbp);
719 set_nilfs_init(nilfs);
722 up_write(&nilfs->ns_sem);
726 nilfs_release_super_block(nilfs);
730 int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump,
733 sector_t seg_start, seg_end;
734 sector_t start = 0, nblocks = 0;
735 unsigned int sects_per_block;
739 sects_per_block = (1 << nilfs->ns_blocksize_bits) /
740 bdev_logical_block_size(nilfs->ns_bdev);
741 for (sn = segnump; sn < segnump + nsegs; sn++) {
742 nilfs_get_segment_range(nilfs, *sn, &seg_start, &seg_end);
746 nblocks = seg_end - seg_start + 1;
747 } else if (start + nblocks == seg_start) {
748 nblocks += seg_end - seg_start + 1;
750 ret = blkdev_issue_discard(nilfs->ns_bdev,
751 start * sects_per_block,
752 nblocks * sects_per_block,
760 ret = blkdev_issue_discard(nilfs->ns_bdev,
761 start * sects_per_block,
762 nblocks * sects_per_block,
767 int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks)
769 unsigned long ncleansegs;
771 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
772 *nblocks = (sector_t)ncleansegs * nilfs->ns_blocks_per_segment;
776 int nilfs_near_disk_full(struct the_nilfs *nilfs)
778 unsigned long ncleansegs, nincsegs;
780 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
781 nincsegs = atomic_read(&nilfs->ns_ndirtyblks) /
782 nilfs->ns_blocks_per_segment + 1;
784 return ncleansegs <= nilfs->ns_nrsvsegs + nincsegs;
787 struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno)
790 struct nilfs_root *root;
792 spin_lock(&nilfs->ns_cptree_lock);
793 n = nilfs->ns_cptree.rb_node;
795 root = rb_entry(n, struct nilfs_root, rb_node);
797 if (cno < root->cno) {
799 } else if (cno > root->cno) {
802 refcount_inc(&root->count);
803 spin_unlock(&nilfs->ns_cptree_lock);
807 spin_unlock(&nilfs->ns_cptree_lock);
813 nilfs_find_or_create_root(struct the_nilfs *nilfs, __u64 cno)
815 struct rb_node **p, *parent;
816 struct nilfs_root *root, *new;
819 root = nilfs_lookup_root(nilfs, cno);
823 new = kzalloc(sizeof(*root), GFP_KERNEL);
827 spin_lock(&nilfs->ns_cptree_lock);
829 p = &nilfs->ns_cptree.rb_node;
834 root = rb_entry(parent, struct nilfs_root, rb_node);
836 if (cno < root->cno) {
838 } else if (cno > root->cno) {
841 refcount_inc(&root->count);
842 spin_unlock(&nilfs->ns_cptree_lock);
851 refcount_set(&new->count, 1);
852 atomic64_set(&new->inodes_count, 0);
853 atomic64_set(&new->blocks_count, 0);
855 rb_link_node(&new->rb_node, parent, p);
856 rb_insert_color(&new->rb_node, &nilfs->ns_cptree);
858 spin_unlock(&nilfs->ns_cptree_lock);
860 err = nilfs_sysfs_create_snapshot_group(new);
869 void nilfs_put_root(struct nilfs_root *root)
871 struct the_nilfs *nilfs = root->nilfs;
873 if (refcount_dec_and_lock(&root->count, &nilfs->ns_cptree_lock)) {
874 rb_erase(&root->rb_node, &nilfs->ns_cptree);
875 spin_unlock(&nilfs->ns_cptree_lock);
877 nilfs_sysfs_delete_snapshot_group(root);