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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/crc32.h>
17#include "nilfs.h"
18#include "segment.h"
19#include "alloc.h"
20#include "cpfile.h"
21#include "sufile.h"
22#include "dat.h"
23#include "segbuf.h"
24
25
26static int nilfs_valid_sb(struct nilfs_super_block *sbp);
27
28void nilfs_set_last_segment(struct the_nilfs *nilfs,
29 sector_t start_blocknr, u64 seq, __u64 cno)
30{
31 spin_lock(&nilfs->ns_last_segment_lock);
32 nilfs->ns_last_pseg = start_blocknr;
33 nilfs->ns_last_seq = seq;
34 nilfs->ns_last_cno = cno;
35
36 if (!nilfs_sb_dirty(nilfs)) {
37 if (nilfs->ns_prev_seq == nilfs->ns_last_seq)
38 goto stay_cursor;
39
40 set_nilfs_sb_dirty(nilfs);
41 }
42 nilfs->ns_prev_seq = nilfs->ns_last_seq;
43
44 stay_cursor:
45 spin_unlock(&nilfs->ns_last_segment_lock);
46}
47
48
49
50
51
52
53
54
55struct the_nilfs *alloc_nilfs(struct super_block *sb)
56{
57 struct the_nilfs *nilfs;
58
59 nilfs = kzalloc(sizeof(*nilfs), GFP_KERNEL);
60 if (!nilfs)
61 return NULL;
62
63 nilfs->ns_sb = sb;
64 nilfs->ns_bdev = sb->s_bdev;
65 atomic_set(&nilfs->ns_ndirtyblks, 0);
66 init_rwsem(&nilfs->ns_sem);
67 mutex_init(&nilfs->ns_snapshot_mount_mutex);
68 INIT_LIST_HEAD(&nilfs->ns_dirty_files);
69 INIT_LIST_HEAD(&nilfs->ns_gc_inodes);
70 spin_lock_init(&nilfs->ns_inode_lock);
71 spin_lock_init(&nilfs->ns_next_gen_lock);
72 spin_lock_init(&nilfs->ns_last_segment_lock);
73 nilfs->ns_cptree = RB_ROOT;
74 spin_lock_init(&nilfs->ns_cptree_lock);
75 init_rwsem(&nilfs->ns_segctor_sem);
76 nilfs->ns_sb_update_freq = NILFS_SB_FREQ;
77
78 return nilfs;
79}
80
81
82
83
84
85void destroy_nilfs(struct the_nilfs *nilfs)
86{
87 might_sleep();
88 if (nilfs_init(nilfs)) {
89 nilfs_sysfs_delete_device_group(nilfs);
90 brelse(nilfs->ns_sbh[0]);
91 brelse(nilfs->ns_sbh[1]);
92 }
93 kfree(nilfs);
94}
95
96static int nilfs_load_super_root(struct the_nilfs *nilfs,
97 struct super_block *sb, sector_t sr_block)
98{
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;
105 int err;
106
107 err = nilfs_read_super_root_block(nilfs, sr_block, &bh_sr, 1);
108 if (unlikely(err))
109 return err;
110
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);
116
117 inode_size = nilfs->ns_inode_size;
118
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);
121 if (err)
122 goto failed;
123
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);
126 if (err)
127 goto failed_dat;
128
129 rawi = (void *)bh_sr->b_data + NILFS_SR_SUFILE_OFFSET(inode_size);
130 err = nilfs_sufile_read(sb, segment_usage_size, rawi,
131 &nilfs->ns_sufile);
132 if (err)
133 goto failed_cpfile;
134
135 raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
136 nilfs->ns_nongc_ctime = le64_to_cpu(raw_sr->sr_nongc_ctime);
137
138 failed:
139 brelse(bh_sr);
140 return err;
141
142 failed_cpfile:
143 iput(nilfs->ns_cpfile);
144
145 failed_dat:
146 iput(nilfs->ns_dat);
147 goto failed;
148}
149
150static void nilfs_init_recovery_info(struct nilfs_recovery_info *ri)
151{
152 memset(ri, 0, sizeof(*ri));
153 INIT_LIST_HEAD(&ri->ri_used_segments);
154}
155
156static void nilfs_clear_recovery_info(struct nilfs_recovery_info *ri)
157{
158 nilfs_dispose_segment_list(&ri->ri_used_segments);
159}
160
161
162
163
164
165
166
167
168
169
170
171static int nilfs_store_log_cursor(struct the_nilfs *nilfs,
172 struct nilfs_super_block *sbp)
173{
174 int ret = 0;
175
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);
179
180 nilfs->ns_prev_seq = nilfs->ns_last_seq;
181 nilfs->ns_seg_seq = nilfs->ns_last_seq;
182 nilfs->ns_segnum =
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_err(nilfs->ns_sb,
187 "pointed segment number is out of range: segnum=%llu, nsegments=%lu",
188 (unsigned long long)nilfs->ns_segnum,
189 nilfs->ns_nsegments);
190 ret = -EINVAL;
191 }
192 return ret;
193}
194
195
196
197
198
199
200
201
202
203
204int load_nilfs(struct the_nilfs *nilfs, struct super_block *sb)
205{
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);
210 int err;
211
212 if (!valid_fs) {
213 nilfs_warn(sb, "mounting unchecked fs");
214 if (s_flags & SB_RDONLY) {
215 nilfs_info(sb,
216 "recovery required for readonly filesystem");
217 nilfs_info(sb,
218 "write access will be enabled during recovery");
219 }
220 }
221
222 nilfs_init_recovery_info(&ri);
223
224 err = nilfs_search_super_root(nilfs, &ri);
225 if (unlikely(err)) {
226 struct nilfs_super_block **sbp = nilfs->ns_sbp;
227 int blocksize;
228
229 if (err != -EINVAL)
230 goto scan_error;
231
232 if (!nilfs_valid_sb(sbp[1])) {
233 nilfs_warn(sb,
234 "unable to fall back to spare super block");
235 goto scan_error;
236 }
237 nilfs_info(sb, "trying rollback from an earlier position");
238
239
240
241
242
243 memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
244 nilfs->ns_crc_seed = le32_to_cpu(sbp[0]->s_crc_seed);
245 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime);
246
247
248 blocksize = BLOCK_SIZE << le32_to_cpu(sbp[0]->s_log_block_size);
249 if (blocksize != nilfs->ns_blocksize) {
250 nilfs_warn(sb,
251 "blocksize differs between two super blocks (%d != %d)",
252 blocksize, nilfs->ns_blocksize);
253 goto scan_error;
254 }
255
256 err = nilfs_store_log_cursor(nilfs, sbp[0]);
257 if (err)
258 goto scan_error;
259
260
261 nilfs->ns_mount_state &= ~NILFS_VALID_FS;
262 valid_fs = 0;
263
264 err = nilfs_search_super_root(nilfs, &ri);
265 if (err)
266 goto scan_error;
267 }
268
269 err = nilfs_load_super_root(nilfs, sb, ri.ri_super_root);
270 if (unlikely(err)) {
271 nilfs_err(sb, "error %d while loading super root", err);
272 goto failed;
273 }
274
275 if (valid_fs)
276 goto skip_recovery;
277
278 if (s_flags & SB_RDONLY) {
279 __u64 features;
280
281 if (nilfs_test_opt(nilfs, NORECOVERY)) {
282 nilfs_info(sb,
283 "norecovery option specified, skipping roll-forward recovery");
284 goto skip_recovery;
285 }
286 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
287 ~NILFS_FEATURE_COMPAT_RO_SUPP;
288 if (features) {
289 nilfs_err(sb,
290 "couldn't proceed with recovery because of unsupported optional features (%llx)",
291 (unsigned long long)features);
292 err = -EROFS;
293 goto failed_unload;
294 }
295 if (really_read_only) {
296 nilfs_err(sb,
297 "write access unavailable, cannot proceed");
298 err = -EROFS;
299 goto failed_unload;
300 }
301 sb->s_flags &= ~SB_RDONLY;
302 } else if (nilfs_test_opt(nilfs, NORECOVERY)) {
303 nilfs_err(sb,
304 "recovery cancelled because norecovery option was specified for a read/write mount");
305 err = -EINVAL;
306 goto failed_unload;
307 }
308
309 err = nilfs_salvage_orphan_logs(nilfs, sb, &ri);
310 if (err)
311 goto failed_unload;
312
313 down_write(&nilfs->ns_sem);
314 nilfs->ns_mount_state |= NILFS_VALID_FS;
315 err = nilfs_cleanup_super(sb);
316 up_write(&nilfs->ns_sem);
317
318 if (err) {
319 nilfs_err(sb,
320 "error %d updating super block. recovery unfinished.",
321 err);
322 goto failed_unload;
323 }
324 nilfs_info(sb, "recovery complete");
325
326 skip_recovery:
327 nilfs_clear_recovery_info(&ri);
328 sb->s_flags = s_flags;
329 return 0;
330
331 scan_error:
332 nilfs_err(sb, "error %d while searching super root", err);
333 goto failed;
334
335 failed_unload:
336 iput(nilfs->ns_cpfile);
337 iput(nilfs->ns_sufile);
338 iput(nilfs->ns_dat);
339
340 failed:
341 nilfs_clear_recovery_info(&ri);
342 sb->s_flags = s_flags;
343 return err;
344}
345
346static unsigned long long nilfs_max_size(unsigned int blkbits)
347{
348 unsigned int max_bits;
349 unsigned long long res = MAX_LFS_FILESIZE;
350
351 max_bits = blkbits + NILFS_BMAP_KEY_BIT;
352 if (max_bits < 64)
353 res = min_t(unsigned long long, res, (1ULL << max_bits) - 1);
354 return res;
355}
356
357
358
359
360
361
362unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs)
363{
364 return max_t(unsigned long, NILFS_MIN_NRSVSEGS,
365 DIV_ROUND_UP(nsegs * nilfs->ns_r_segments_percentage,
366 100));
367}
368
369void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs)
370{
371 nilfs->ns_nsegments = nsegs;
372 nilfs->ns_nrsvsegs = nilfs_nrsvsegs(nilfs, nsegs);
373}
374
375static int nilfs_store_disk_layout(struct the_nilfs *nilfs,
376 struct nilfs_super_block *sbp)
377{
378 if (le32_to_cpu(sbp->s_rev_level) < NILFS_MIN_SUPP_REV) {
379 nilfs_err(nilfs->ns_sb,
380 "unsupported revision (superblock rev.=%d.%d, current rev.=%d.%d). Please check the version of mkfs.nilfs(2).",
381 le32_to_cpu(sbp->s_rev_level),
382 le16_to_cpu(sbp->s_minor_rev_level),
383 NILFS_CURRENT_REV, NILFS_MINOR_REV);
384 return -EINVAL;
385 }
386 nilfs->ns_sbsize = le16_to_cpu(sbp->s_bytes);
387 if (nilfs->ns_sbsize > BLOCK_SIZE)
388 return -EINVAL;
389
390 nilfs->ns_inode_size = le16_to_cpu(sbp->s_inode_size);
391 if (nilfs->ns_inode_size > nilfs->ns_blocksize) {
392 nilfs_err(nilfs->ns_sb, "too large inode size: %d bytes",
393 nilfs->ns_inode_size);
394 return -EINVAL;
395 } else if (nilfs->ns_inode_size < NILFS_MIN_INODE_SIZE) {
396 nilfs_err(nilfs->ns_sb, "too small inode size: %d bytes",
397 nilfs->ns_inode_size);
398 return -EINVAL;
399 }
400
401 nilfs->ns_first_ino = le32_to_cpu(sbp->s_first_ino);
402
403 nilfs->ns_blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment);
404 if (nilfs->ns_blocks_per_segment < NILFS_SEG_MIN_BLOCKS) {
405 nilfs_err(nilfs->ns_sb, "too short segment: %lu blocks",
406 nilfs->ns_blocks_per_segment);
407 return -EINVAL;
408 }
409
410 nilfs->ns_first_data_block = le64_to_cpu(sbp->s_first_data_block);
411 nilfs->ns_r_segments_percentage =
412 le32_to_cpu(sbp->s_r_segments_percentage);
413 if (nilfs->ns_r_segments_percentage < 1 ||
414 nilfs->ns_r_segments_percentage > 99) {
415 nilfs_err(nilfs->ns_sb,
416 "invalid reserved segments percentage: %lu",
417 nilfs->ns_r_segments_percentage);
418 return -EINVAL;
419 }
420
421 nilfs_set_nsegments(nilfs, le64_to_cpu(sbp->s_nsegments));
422 nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed);
423 return 0;
424}
425
426static int nilfs_valid_sb(struct nilfs_super_block *sbp)
427{
428 static unsigned char sum[4];
429 const int sumoff = offsetof(struct nilfs_super_block, s_sum);
430 size_t bytes;
431 u32 crc;
432
433 if (!sbp || le16_to_cpu(sbp->s_magic) != NILFS_SUPER_MAGIC)
434 return 0;
435 bytes = le16_to_cpu(sbp->s_bytes);
436 if (bytes < sumoff + 4 || bytes > BLOCK_SIZE)
437 return 0;
438 crc = crc32_le(le32_to_cpu(sbp->s_crc_seed), (unsigned char *)sbp,
439 sumoff);
440 crc = crc32_le(crc, sum, 4);
441 crc = crc32_le(crc, (unsigned char *)sbp + sumoff + 4,
442 bytes - sumoff - 4);
443 return crc == le32_to_cpu(sbp->s_sum);
444}
445
446static int nilfs_sb2_bad_offset(struct nilfs_super_block *sbp, u64 offset)
447{
448 return offset < ((le64_to_cpu(sbp->s_nsegments) *
449 le32_to_cpu(sbp->s_blocks_per_segment)) <<
450 (le32_to_cpu(sbp->s_log_block_size) + 10));
451}
452
453static void nilfs_release_super_block(struct the_nilfs *nilfs)
454{
455 int i;
456
457 for (i = 0; i < 2; i++) {
458 if (nilfs->ns_sbp[i]) {
459 brelse(nilfs->ns_sbh[i]);
460 nilfs->ns_sbh[i] = NULL;
461 nilfs->ns_sbp[i] = NULL;
462 }
463 }
464}
465
466void nilfs_fall_back_super_block(struct the_nilfs *nilfs)
467{
468 brelse(nilfs->ns_sbh[0]);
469 nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
470 nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
471 nilfs->ns_sbh[1] = NULL;
472 nilfs->ns_sbp[1] = NULL;
473}
474
475void nilfs_swap_super_block(struct the_nilfs *nilfs)
476{
477 struct buffer_head *tsbh = nilfs->ns_sbh[0];
478 struct nilfs_super_block *tsbp = nilfs->ns_sbp[0];
479
480 nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
481 nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
482 nilfs->ns_sbh[1] = tsbh;
483 nilfs->ns_sbp[1] = tsbp;
484}
485
486static int nilfs_load_super_block(struct the_nilfs *nilfs,
487 struct super_block *sb, int blocksize,
488 struct nilfs_super_block **sbpp)
489{
490 struct nilfs_super_block **sbp = nilfs->ns_sbp;
491 struct buffer_head **sbh = nilfs->ns_sbh;
492 u64 sb2off = NILFS_SB2_OFFSET_BYTES(nilfs->ns_bdev->bd_inode->i_size);
493 int valid[2], swp = 0;
494
495 sbp[0] = nilfs_read_super_block(sb, NILFS_SB_OFFSET_BYTES, blocksize,
496 &sbh[0]);
497 sbp[1] = nilfs_read_super_block(sb, sb2off, blocksize, &sbh[1]);
498
499 if (!sbp[0]) {
500 if (!sbp[1]) {
501 nilfs_err(sb, "unable to read superblock");
502 return -EIO;
503 }
504 nilfs_warn(sb,
505 "unable to read primary superblock (blocksize = %d)",
506 blocksize);
507 } else if (!sbp[1]) {
508 nilfs_warn(sb,
509 "unable to read secondary superblock (blocksize = %d)",
510 blocksize);
511 }
512
513
514
515
516
517 valid[0] = nilfs_valid_sb(sbp[0]);
518 valid[1] = nilfs_valid_sb(sbp[1]);
519 swp = valid[1] && (!valid[0] ||
520 le64_to_cpu(sbp[1]->s_last_cno) >
521 le64_to_cpu(sbp[0]->s_last_cno));
522
523 if (valid[swp] && nilfs_sb2_bad_offset(sbp[swp], sb2off)) {
524 brelse(sbh[1]);
525 sbh[1] = NULL;
526 sbp[1] = NULL;
527 valid[1] = 0;
528 swp = 0;
529 }
530 if (!valid[swp]) {
531 nilfs_release_super_block(nilfs);
532 nilfs_err(sb, "couldn't find nilfs on the device");
533 return -EINVAL;
534 }
535
536 if (!valid[!swp])
537 nilfs_warn(sb,
538 "broken superblock, retrying with spare superblock (blocksize = %d)",
539 blocksize);
540 if (swp)
541 nilfs_swap_super_block(nilfs);
542
543 nilfs->ns_sbwcount = 0;
544 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime);
545 nilfs->ns_prot_seq = le64_to_cpu(sbp[valid[1] & !swp]->s_last_seq);
546 *sbpp = sbp[0];
547 return 0;
548}
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data)
564{
565 struct nilfs_super_block *sbp;
566 int blocksize;
567 int err;
568
569 down_write(&nilfs->ns_sem);
570
571 blocksize = sb_min_blocksize(sb, NILFS_MIN_BLOCK_SIZE);
572 if (!blocksize) {
573 nilfs_err(sb, "unable to set blocksize");
574 err = -EINVAL;
575 goto out;
576 }
577 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
578 if (err)
579 goto out;
580
581 err = nilfs_store_magic_and_option(sb, sbp, data);
582 if (err)
583 goto failed_sbh;
584
585 err = nilfs_check_feature_compatibility(sb, sbp);
586 if (err)
587 goto failed_sbh;
588
589 blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size);
590 if (blocksize < NILFS_MIN_BLOCK_SIZE ||
591 blocksize > NILFS_MAX_BLOCK_SIZE) {
592 nilfs_err(sb,
593 "couldn't mount because of unsupported filesystem blocksize %d",
594 blocksize);
595 err = -EINVAL;
596 goto failed_sbh;
597 }
598 if (sb->s_blocksize != blocksize) {
599 int hw_blocksize = bdev_logical_block_size(sb->s_bdev);
600
601 if (blocksize < hw_blocksize) {
602 nilfs_err(sb,
603 "blocksize %d too small for device (sector-size = %d)",
604 blocksize, hw_blocksize);
605 err = -EINVAL;
606 goto failed_sbh;
607 }
608 nilfs_release_super_block(nilfs);
609 sb_set_blocksize(sb, blocksize);
610
611 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
612 if (err)
613 goto out;
614
615
616
617
618 }
619 nilfs->ns_blocksize_bits = sb->s_blocksize_bits;
620 nilfs->ns_blocksize = blocksize;
621
622 get_random_bytes(&nilfs->ns_next_generation,
623 sizeof(nilfs->ns_next_generation));
624
625 err = nilfs_store_disk_layout(nilfs, sbp);
626 if (err)
627 goto failed_sbh;
628
629 sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits);
630
631 nilfs->ns_mount_state = le16_to_cpu(sbp->s_state);
632
633 err = nilfs_store_log_cursor(nilfs, sbp);
634 if (err)
635 goto failed_sbh;
636
637 err = nilfs_sysfs_create_device_group(sb);
638 if (err)
639 goto failed_sbh;
640
641 set_nilfs_init(nilfs);
642 err = 0;
643 out:
644 up_write(&nilfs->ns_sem);
645 return err;
646
647 failed_sbh:
648 nilfs_release_super_block(nilfs);
649 goto out;
650}
651
652int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump,
653 size_t nsegs)
654{
655 sector_t seg_start, seg_end;
656 sector_t start = 0, nblocks = 0;
657 unsigned int sects_per_block;
658 __u64 *sn;
659 int ret = 0;
660
661 sects_per_block = (1 << nilfs->ns_blocksize_bits) /
662 bdev_logical_block_size(nilfs->ns_bdev);
663 for (sn = segnump; sn < segnump + nsegs; sn++) {
664 nilfs_get_segment_range(nilfs, *sn, &seg_start, &seg_end);
665
666 if (!nblocks) {
667 start = seg_start;
668 nblocks = seg_end - seg_start + 1;
669 } else if (start + nblocks == seg_start) {
670 nblocks += seg_end - seg_start + 1;
671 } else {
672 ret = blkdev_issue_discard(nilfs->ns_bdev,
673 start * sects_per_block,
674 nblocks * sects_per_block,
675 GFP_NOFS, 0);
676 if (ret < 0)
677 return ret;
678 nblocks = 0;
679 }
680 }
681 if (nblocks)
682 ret = blkdev_issue_discard(nilfs->ns_bdev,
683 start * sects_per_block,
684 nblocks * sects_per_block,
685 GFP_NOFS, 0);
686 return ret;
687}
688
689int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks)
690{
691 unsigned long ncleansegs;
692
693 down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
694 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
695 up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
696 *nblocks = (sector_t)ncleansegs * nilfs->ns_blocks_per_segment;
697 return 0;
698}
699
700int nilfs_near_disk_full(struct the_nilfs *nilfs)
701{
702 unsigned long ncleansegs, nincsegs;
703
704 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
705 nincsegs = atomic_read(&nilfs->ns_ndirtyblks) /
706 nilfs->ns_blocks_per_segment + 1;
707
708 return ncleansegs <= nilfs->ns_nrsvsegs + nincsegs;
709}
710
711struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno)
712{
713 struct rb_node *n;
714 struct nilfs_root *root;
715
716 spin_lock(&nilfs->ns_cptree_lock);
717 n = nilfs->ns_cptree.rb_node;
718 while (n) {
719 root = rb_entry(n, struct nilfs_root, rb_node);
720
721 if (cno < root->cno) {
722 n = n->rb_left;
723 } else if (cno > root->cno) {
724 n = n->rb_right;
725 } else {
726 refcount_inc(&root->count);
727 spin_unlock(&nilfs->ns_cptree_lock);
728 return root;
729 }
730 }
731 spin_unlock(&nilfs->ns_cptree_lock);
732
733 return NULL;
734}
735
736struct nilfs_root *
737nilfs_find_or_create_root(struct the_nilfs *nilfs, __u64 cno)
738{
739 struct rb_node **p, *parent;
740 struct nilfs_root *root, *new;
741 int err;
742
743 root = nilfs_lookup_root(nilfs, cno);
744 if (root)
745 return root;
746
747 new = kzalloc(sizeof(*root), GFP_KERNEL);
748 if (!new)
749 return NULL;
750
751 spin_lock(&nilfs->ns_cptree_lock);
752
753 p = &nilfs->ns_cptree.rb_node;
754 parent = NULL;
755
756 while (*p) {
757 parent = *p;
758 root = rb_entry(parent, struct nilfs_root, rb_node);
759
760 if (cno < root->cno) {
761 p = &(*p)->rb_left;
762 } else if (cno > root->cno) {
763 p = &(*p)->rb_right;
764 } else {
765 refcount_inc(&root->count);
766 spin_unlock(&nilfs->ns_cptree_lock);
767 kfree(new);
768 return root;
769 }
770 }
771
772 new->cno = cno;
773 new->ifile = NULL;
774 new->nilfs = nilfs;
775 refcount_set(&new->count, 1);
776 atomic64_set(&new->inodes_count, 0);
777 atomic64_set(&new->blocks_count, 0);
778
779 rb_link_node(&new->rb_node, parent, p);
780 rb_insert_color(&new->rb_node, &nilfs->ns_cptree);
781
782 spin_unlock(&nilfs->ns_cptree_lock);
783
784 err = nilfs_sysfs_create_snapshot_group(new);
785 if (err) {
786 kfree(new);
787 new = NULL;
788 }
789
790 return new;
791}
792
793void nilfs_put_root(struct nilfs_root *root)
794{
795 struct the_nilfs *nilfs = root->nilfs;
796
797 if (refcount_dec_and_lock(&root->count, &nilfs->ns_cptree_lock)) {
798 rb_erase(&root->rb_node, &nilfs->ns_cptree);
799 spin_unlock(&nilfs->ns_cptree_lock);
800
801 nilfs_sysfs_delete_snapshot_group(root);
802 iput(root->ifile);
803
804 kfree(root);
805 }
806}
807
