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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_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);
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_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");
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_msg(sb, KERN_WARNING,
234 "unable to fall back to spare super block");
235 goto scan_error;
236 }
237 nilfs_msg(sb, KERN_INFO,
238 "trying rollback from an earlier position");
239
240
241
242
243
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);
247
248
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);
254 goto scan_error;
255 }
256
257 err = nilfs_store_log_cursor(nilfs, sbp[0]);
258 if (err)
259 goto scan_error;
260
261
262 nilfs->ns_mount_state &= ~NILFS_VALID_FS;
263 valid_fs = 0;
264
265 err = nilfs_search_super_root(nilfs, &ri);
266 if (err)
267 goto scan_error;
268 }
269
270 err = nilfs_load_super_root(nilfs, sb, ri.ri_super_root);
271 if (unlikely(err)) {
272 nilfs_msg(sb, KERN_ERR, "error %d while loading super root",
273 err);
274 goto failed;
275 }
276
277 if (valid_fs)
278 goto skip_recovery;
279
280 if (s_flags & SB_RDONLY) {
281 __u64 features;
282
283 if (nilfs_test_opt(nilfs, NORECOVERY)) {
284 nilfs_msg(sb, KERN_INFO,
285 "norecovery option specified, skipping roll-forward recovery");
286 goto skip_recovery;
287 }
288 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
289 ~NILFS_FEATURE_COMPAT_RO_SUPP;
290 if (features) {
291 nilfs_msg(sb, KERN_ERR,
292 "couldn't proceed with recovery because of unsupported optional features (%llx)",
293 (unsigned long long)features);
294 err = -EROFS;
295 goto failed_unload;
296 }
297 if (really_read_only) {
298 nilfs_msg(sb, KERN_ERR,
299 "write access unavailable, cannot proceed");
300 err = -EROFS;
301 goto failed_unload;
302 }
303 sb->s_flags &= ~SB_RDONLY;
304 } else if (nilfs_test_opt(nilfs, NORECOVERY)) {
305 nilfs_msg(sb, KERN_ERR,
306 "recovery cancelled because norecovery option was specified for a read/write mount");
307 err = -EINVAL;
308 goto failed_unload;
309 }
310
311 err = nilfs_salvage_orphan_logs(nilfs, sb, &ri);
312 if (err)
313 goto failed_unload;
314
315 down_write(&nilfs->ns_sem);
316 nilfs->ns_mount_state |= NILFS_VALID_FS;
317 err = nilfs_cleanup_super(sb);
318 up_write(&nilfs->ns_sem);
319
320 if (err) {
321 nilfs_msg(sb, KERN_ERR,
322 "error %d updating super block. recovery unfinished.",
323 err);
324 goto failed_unload;
325 }
326 nilfs_msg(sb, KERN_INFO, "recovery complete");
327
328 skip_recovery:
329 nilfs_clear_recovery_info(&ri);
330 sb->s_flags = s_flags;
331 return 0;
332
333 scan_error:
334 nilfs_msg(sb, KERN_ERR, "error %d while searching super root", err);
335 goto failed;
336
337 failed_unload:
338 iput(nilfs->ns_cpfile);
339 iput(nilfs->ns_sufile);
340 iput(nilfs->ns_dat);
341
342 failed:
343 nilfs_clear_recovery_info(&ri);
344 sb->s_flags = s_flags;
345 return err;
346}
347
348static unsigned long long nilfs_max_size(unsigned int blkbits)
349{
350 unsigned int max_bits;
351 unsigned long long res = MAX_LFS_FILESIZE;
352
353 max_bits = blkbits + NILFS_BMAP_KEY_BIT;
354 if (max_bits < 64)
355 res = min_t(unsigned long long, res, (1ULL << max_bits) - 1);
356 return res;
357}
358
359
360
361
362
363
364unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs)
365{
366 return max_t(unsigned long, NILFS_MIN_NRSVSEGS,
367 DIV_ROUND_UP(nsegs * nilfs->ns_r_segments_percentage,
368 100));
369}
370
371void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs)
372{
373 nilfs->ns_nsegments = nsegs;
374 nilfs->ns_nrsvsegs = nilfs_nrsvsegs(nilfs, nsegs);
375}
376
377static int nilfs_store_disk_layout(struct the_nilfs *nilfs,
378 struct nilfs_super_block *sbp)
379{
380 if (le32_to_cpu(sbp->s_rev_level) < NILFS_MIN_SUPP_REV) {
381 nilfs_msg(nilfs->ns_sb, KERN_ERR,
382 "unsupported revision (superblock rev.=%d.%d, current rev.=%d.%d). Please check the version of mkfs.nilfs(2).",
383 le32_to_cpu(sbp->s_rev_level),
384 le16_to_cpu(sbp->s_minor_rev_level),
385 NILFS_CURRENT_REV, NILFS_MINOR_REV);
386 return -EINVAL;
387 }
388 nilfs->ns_sbsize = le16_to_cpu(sbp->s_bytes);
389 if (nilfs->ns_sbsize > BLOCK_SIZE)
390 return -EINVAL;
391
392 nilfs->ns_inode_size = le16_to_cpu(sbp->s_inode_size);
393 if (nilfs->ns_inode_size > nilfs->ns_blocksize) {
394 nilfs_msg(nilfs->ns_sb, KERN_ERR,
395 "too large inode size: %d bytes",
396 nilfs->ns_inode_size);
397 return -EINVAL;
398 } else if (nilfs->ns_inode_size < NILFS_MIN_INODE_SIZE) {
399 nilfs_msg(nilfs->ns_sb, KERN_ERR,
400 "too small inode size: %d bytes",
401 nilfs->ns_inode_size);
402 return -EINVAL;
403 }
404
405 nilfs->ns_first_ino = le32_to_cpu(sbp->s_first_ino);
406
407 nilfs->ns_blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment);
408 if (nilfs->ns_blocks_per_segment < NILFS_SEG_MIN_BLOCKS) {
409 nilfs_msg(nilfs->ns_sb, KERN_ERR,
410 "too short segment: %lu blocks",
411 nilfs->ns_blocks_per_segment);
412 return -EINVAL;
413 }
414
415 nilfs->ns_first_data_block = le64_to_cpu(sbp->s_first_data_block);
416 nilfs->ns_r_segments_percentage =
417 le32_to_cpu(sbp->s_r_segments_percentage);
418 if (nilfs->ns_r_segments_percentage < 1 ||
419 nilfs->ns_r_segments_percentage > 99) {
420 nilfs_msg(nilfs->ns_sb, KERN_ERR,
421 "invalid reserved segments percentage: %lu",
422 nilfs->ns_r_segments_percentage);
423 return -EINVAL;
424 }
425
426 nilfs_set_nsegments(nilfs, le64_to_cpu(sbp->s_nsegments));
427 nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed);
428 return 0;
429}
430
431static int nilfs_valid_sb(struct nilfs_super_block *sbp)
432{
433 static unsigned char sum[4];
434 const int sumoff = offsetof(struct nilfs_super_block, s_sum);
435 size_t bytes;
436 u32 crc;
437
438 if (!sbp || le16_to_cpu(sbp->s_magic) != NILFS_SUPER_MAGIC)
439 return 0;
440 bytes = le16_to_cpu(sbp->s_bytes);
441 if (bytes < sumoff + 4 || bytes > BLOCK_SIZE)
442 return 0;
443 crc = crc32_le(le32_to_cpu(sbp->s_crc_seed), (unsigned char *)sbp,
444 sumoff);
445 crc = crc32_le(crc, sum, 4);
446 crc = crc32_le(crc, (unsigned char *)sbp + sumoff + 4,
447 bytes - sumoff - 4);
448 return crc == le32_to_cpu(sbp->s_sum);
449}
450
451static int nilfs_sb2_bad_offset(struct nilfs_super_block *sbp, u64 offset)
452{
453 return offset < ((le64_to_cpu(sbp->s_nsegments) *
454 le32_to_cpu(sbp->s_blocks_per_segment)) <<
455 (le32_to_cpu(sbp->s_log_block_size) + 10));
456}
457
458static void nilfs_release_super_block(struct the_nilfs *nilfs)
459{
460 int i;
461
462 for (i = 0; i < 2; i++) {
463 if (nilfs->ns_sbp[i]) {
464 brelse(nilfs->ns_sbh[i]);
465 nilfs->ns_sbh[i] = NULL;
466 nilfs->ns_sbp[i] = NULL;
467 }
468 }
469}
470
471void nilfs_fall_back_super_block(struct the_nilfs *nilfs)
472{
473 brelse(nilfs->ns_sbh[0]);
474 nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
475 nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
476 nilfs->ns_sbh[1] = NULL;
477 nilfs->ns_sbp[1] = NULL;
478}
479
480void nilfs_swap_super_block(struct the_nilfs *nilfs)
481{
482 struct buffer_head *tsbh = nilfs->ns_sbh[0];
483 struct nilfs_super_block *tsbp = nilfs->ns_sbp[0];
484
485 nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
486 nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
487 nilfs->ns_sbh[1] = tsbh;
488 nilfs->ns_sbp[1] = tsbp;
489}
490
491static int nilfs_load_super_block(struct the_nilfs *nilfs,
492 struct super_block *sb, int blocksize,
493 struct nilfs_super_block **sbpp)
494{
495 struct nilfs_super_block **sbp = nilfs->ns_sbp;
496 struct buffer_head **sbh = nilfs->ns_sbh;
497 u64 sb2off = NILFS_SB2_OFFSET_BYTES(nilfs->ns_bdev->bd_inode->i_size);
498 int valid[2], swp = 0;
499
500 sbp[0] = nilfs_read_super_block(sb, NILFS_SB_OFFSET_BYTES, blocksize,
501 &sbh[0]);
502 sbp[1] = nilfs_read_super_block(sb, sb2off, blocksize, &sbh[1]);
503
504 if (!sbp[0]) {
505 if (!sbp[1]) {
506 nilfs_msg(sb, KERN_ERR, "unable to read superblock");
507 return -EIO;
508 }
509 nilfs_msg(sb, KERN_WARNING,
510 "unable to read primary superblock (blocksize = %d)",
511 blocksize);
512 } else if (!sbp[1]) {
513 nilfs_msg(sb, KERN_WARNING,
514 "unable to read secondary superblock (blocksize = %d)",
515 blocksize);
516 }
517
518
519
520
521
522 valid[0] = nilfs_valid_sb(sbp[0]);
523 valid[1] = nilfs_valid_sb(sbp[1]);
524 swp = valid[1] && (!valid[0] ||
525 le64_to_cpu(sbp[1]->s_last_cno) >
526 le64_to_cpu(sbp[0]->s_last_cno));
527
528 if (valid[swp] && nilfs_sb2_bad_offset(sbp[swp], sb2off)) {
529 brelse(sbh[1]);
530 sbh[1] = NULL;
531 sbp[1] = NULL;
532 valid[1] = 0;
533 swp = 0;
534 }
535 if (!valid[swp]) {
536 nilfs_release_super_block(nilfs);
537 nilfs_msg(sb, KERN_ERR, "couldn't find nilfs on the device");
538 return -EINVAL;
539 }
540
541 if (!valid[!swp])
542 nilfs_msg(sb, KERN_WARNING,
543 "broken superblock, retrying with spare superblock (blocksize = %d)",
544 blocksize);
545 if (swp)
546 nilfs_swap_super_block(nilfs);
547
548 nilfs->ns_sbwcount = 0;
549 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime);
550 nilfs->ns_prot_seq = le64_to_cpu(sbp[valid[1] & !swp]->s_last_seq);
551 *sbpp = sbp[0];
552 return 0;
553}
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data)
569{
570 struct nilfs_super_block *sbp;
571 int blocksize;
572 int err;
573
574 down_write(&nilfs->ns_sem);
575
576 blocksize = sb_min_blocksize(sb, NILFS_MIN_BLOCK_SIZE);
577 if (!blocksize) {
578 nilfs_msg(sb, KERN_ERR, "unable to set blocksize");
579 err = -EINVAL;
580 goto out;
581 }
582 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
583 if (err)
584 goto out;
585
586 err = nilfs_store_magic_and_option(sb, sbp, data);
587 if (err)
588 goto failed_sbh;
589
590 err = nilfs_check_feature_compatibility(sb, sbp);
591 if (err)
592 goto failed_sbh;
593
594 blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size);
595 if (blocksize < NILFS_MIN_BLOCK_SIZE ||
596 blocksize > NILFS_MAX_BLOCK_SIZE) {
597 nilfs_msg(sb, KERN_ERR,
598 "couldn't mount because of unsupported filesystem blocksize %d",
599 blocksize);
600 err = -EINVAL;
601 goto failed_sbh;
602 }
603 if (sb->s_blocksize != blocksize) {
604 int hw_blocksize = bdev_logical_block_size(sb->s_bdev);
605
606 if (blocksize < hw_blocksize) {
607 nilfs_msg(sb, KERN_ERR,
608 "blocksize %d too small for device (sector-size = %d)",
609 blocksize, hw_blocksize);
610 err = -EINVAL;
611 goto failed_sbh;
612 }
613 nilfs_release_super_block(nilfs);
614 sb_set_blocksize(sb, blocksize);
615
616 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
617 if (err)
618 goto out;
619
620
621
622
623 }
624 nilfs->ns_blocksize_bits = sb->s_blocksize_bits;
625 nilfs->ns_blocksize = blocksize;
626
627 get_random_bytes(&nilfs->ns_next_generation,
628 sizeof(nilfs->ns_next_generation));
629
630 err = nilfs_store_disk_layout(nilfs, sbp);
631 if (err)
632 goto failed_sbh;
633
634 sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits);
635
636 nilfs->ns_mount_state = le16_to_cpu(sbp->s_state);
637
638 err = nilfs_store_log_cursor(nilfs, sbp);
639 if (err)
640 goto failed_sbh;
641
642 err = nilfs_sysfs_create_device_group(sb);
643 if (err)
644 goto failed_sbh;
645
646 set_nilfs_init(nilfs);
647 err = 0;
648 out:
649 up_write(&nilfs->ns_sem);
650 return err;
651
652 failed_sbh:
653 nilfs_release_super_block(nilfs);
654 goto out;
655}
656
657int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump,
658 size_t nsegs)
659{
660 sector_t seg_start, seg_end;
661 sector_t start = 0, nblocks = 0;
662 unsigned int sects_per_block;
663 __u64 *sn;
664 int ret = 0;
665
666 sects_per_block = (1 << nilfs->ns_blocksize_bits) /
667 bdev_logical_block_size(nilfs->ns_bdev);
668 for (sn = segnump; sn < segnump + nsegs; sn++) {
669 nilfs_get_segment_range(nilfs, *sn, &seg_start, &seg_end);
670
671 if (!nblocks) {
672 start = seg_start;
673 nblocks = seg_end - seg_start + 1;
674 } else if (start + nblocks == seg_start) {
675 nblocks += seg_end - seg_start + 1;
676 } else {
677 ret = blkdev_issue_discard(nilfs->ns_bdev,
678 start * sects_per_block,
679 nblocks * sects_per_block,
680 GFP_NOFS, 0);
681 if (ret < 0)
682 return ret;
683 nblocks = 0;
684 }
685 }
686 if (nblocks)
687 ret = blkdev_issue_discard(nilfs->ns_bdev,
688 start * sects_per_block,
689 nblocks * sects_per_block,
690 GFP_NOFS, 0);
691 return ret;
692}
693
694int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks)
695{
696 unsigned long ncleansegs;
697
698 down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
699 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
700 up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
701 *nblocks = (sector_t)ncleansegs * nilfs->ns_blocks_per_segment;
702 return 0;
703}
704
705int nilfs_near_disk_full(struct the_nilfs *nilfs)
706{
707 unsigned long ncleansegs, nincsegs;
708
709 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
710 nincsegs = atomic_read(&nilfs->ns_ndirtyblks) /
711 nilfs->ns_blocks_per_segment + 1;
712
713 return ncleansegs <= nilfs->ns_nrsvsegs + nincsegs;
714}
715
716struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno)
717{
718 struct rb_node *n;
719 struct nilfs_root *root;
720
721 spin_lock(&nilfs->ns_cptree_lock);
722 n = nilfs->ns_cptree.rb_node;
723 while (n) {
724 root = rb_entry(n, struct nilfs_root, rb_node);
725
726 if (cno < root->cno) {
727 n = n->rb_left;
728 } else if (cno > root->cno) {
729 n = n->rb_right;
730 } else {
731 refcount_inc(&root->count);
732 spin_unlock(&nilfs->ns_cptree_lock);
733 return root;
734 }
735 }
736 spin_unlock(&nilfs->ns_cptree_lock);
737
738 return NULL;
739}
740
741struct nilfs_root *
742nilfs_find_or_create_root(struct the_nilfs *nilfs, __u64 cno)
743{
744 struct rb_node **p, *parent;
745 struct nilfs_root *root, *new;
746 int err;
747
748 root = nilfs_lookup_root(nilfs, cno);
749 if (root)
750 return root;
751
752 new = kzalloc(sizeof(*root), GFP_KERNEL);
753 if (!new)
754 return NULL;
755
756 spin_lock(&nilfs->ns_cptree_lock);
757
758 p = &nilfs->ns_cptree.rb_node;
759 parent = NULL;
760
761 while (*p) {
762 parent = *p;
763 root = rb_entry(parent, struct nilfs_root, rb_node);
764
765 if (cno < root->cno) {
766 p = &(*p)->rb_left;
767 } else if (cno > root->cno) {
768 p = &(*p)->rb_right;
769 } else {
770 refcount_inc(&root->count);
771 spin_unlock(&nilfs->ns_cptree_lock);
772 kfree(new);
773 return root;
774 }
775 }
776
777 new->cno = cno;
778 new->ifile = NULL;
779 new->nilfs = nilfs;
780 refcount_set(&new->count, 1);
781 atomic64_set(&new->inodes_count, 0);
782 atomic64_set(&new->blocks_count, 0);
783
784 rb_link_node(&new->rb_node, parent, p);
785 rb_insert_color(&new->rb_node, &nilfs->ns_cptree);
786
787 spin_unlock(&nilfs->ns_cptree_lock);
788
789 err = nilfs_sysfs_create_snapshot_group(new);
790 if (err) {
791 kfree(new);
792 new = NULL;
793 }
794
795 return new;
796}
797
798void nilfs_put_root(struct nilfs_root *root)
799{
800 if (refcount_dec_and_test(&root->count)) {
801 struct the_nilfs *nilfs = root->nilfs;
802
803 nilfs_sysfs_delete_snapshot_group(root);
804
805 spin_lock(&nilfs->ns_cptree_lock);
806 rb_erase(&root->rb_node, &nilfs->ns_cptree);
807 spin_unlock(&nilfs->ns_cptree_lock);
808 iput(root->ifile);
809
810 kfree(root);
811 }
812}
813
