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1/*
2 * the_nilfs.c - the_nilfs shared structure.
3 *
4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
5 *
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.
10 *
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.
15 *
16 * Written by Ryusuke Konishi.
17 *
18 */
19
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>
26#include "nilfs.h"
27#include "segment.h"
28#include "alloc.h"
29#include "cpfile.h"
30#include "sufile.h"
31#include "dat.h"
32#include "segbuf.h"
33
34
35static int nilfs_valid_sb(struct nilfs_super_block *sbp);
36
37void nilfs_set_last_segment(struct the_nilfs *nilfs,
38 sector_t start_blocknr, u64 seq, __u64 cno)
39{
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;
44
45 if (!nilfs_sb_dirty(nilfs)) {
46 if (nilfs->ns_prev_seq == nilfs->ns_last_seq)
47 goto stay_cursor;
48
49 set_nilfs_sb_dirty(nilfs);
50 }
51 nilfs->ns_prev_seq = nilfs->ns_last_seq;
52
53 stay_cursor:
54 spin_unlock(&nilfs->ns_last_segment_lock);
55}
56
57/**
58 * alloc_nilfs - allocate a nilfs object
59 * @sb: super block instance
60 *
61 * Return Value: On success, pointer to the_nilfs is returned.
62 * On error, NULL is returned.
63 */
64struct the_nilfs *alloc_nilfs(struct super_block *sb)
65{
66 struct the_nilfs *nilfs;
67
68 nilfs = kzalloc(sizeof(*nilfs), GFP_KERNEL);
69 if (!nilfs)
70 return NULL;
71
72 nilfs->ns_sb = sb;
73 nilfs->ns_bdev = sb->s_bdev;
74 atomic_set(&nilfs->ns_ndirtyblks, 0);
75 init_rwsem(&nilfs->ns_sem);
76 mutex_init(&nilfs->ns_snapshot_mount_mutex);
77 INIT_LIST_HEAD(&nilfs->ns_dirty_files);
78 INIT_LIST_HEAD(&nilfs->ns_gc_inodes);
79 spin_lock_init(&nilfs->ns_inode_lock);
80 spin_lock_init(&nilfs->ns_next_gen_lock);
81 spin_lock_init(&nilfs->ns_last_segment_lock);
82 nilfs->ns_cptree = RB_ROOT;
83 spin_lock_init(&nilfs->ns_cptree_lock);
84 init_rwsem(&nilfs->ns_segctor_sem);
85 nilfs->ns_sb_update_freq = NILFS_SB_FREQ;
86
87 return nilfs;
88}
89
90/**
91 * destroy_nilfs - destroy nilfs object
92 * @nilfs: nilfs object to be released
93 */
94void destroy_nilfs(struct the_nilfs *nilfs)
95{
96 might_sleep();
97 if (nilfs_init(nilfs)) {
98 nilfs_sysfs_delete_device_group(nilfs);
99 brelse(nilfs->ns_sbh[0]);
100 brelse(nilfs->ns_sbh[1]);
101 }
102 kfree(nilfs);
103}
104
105static int nilfs_load_super_root(struct the_nilfs *nilfs,
106 struct super_block *sb, sector_t sr_block)
107{
108 struct buffer_head *bh_sr;
109 struct nilfs_super_root *raw_sr;
110 struct nilfs_super_block **sbp = nilfs->ns_sbp;
111 struct nilfs_inode *rawi;
112 unsigned int dat_entry_size, segment_usage_size, checkpoint_size;
113 unsigned int inode_size;
114 int err;
115
116 err = nilfs_read_super_root_block(nilfs, sr_block, &bh_sr, 1);
117 if (unlikely(err))
118 return err;
119
120 down_read(&nilfs->ns_sem);
121 dat_entry_size = le16_to_cpu(sbp[0]->s_dat_entry_size);
122 checkpoint_size = le16_to_cpu(sbp[0]->s_checkpoint_size);
123 segment_usage_size = le16_to_cpu(sbp[0]->s_segment_usage_size);
124 up_read(&nilfs->ns_sem);
125
126 inode_size = nilfs->ns_inode_size;
127
128 rawi = (void *)bh_sr->b_data + NILFS_SR_DAT_OFFSET(inode_size);
129 err = nilfs_dat_read(sb, dat_entry_size, rawi, &nilfs->ns_dat);
130 if (err)
131 goto failed;
132
133 rawi = (void *)bh_sr->b_data + NILFS_SR_CPFILE_OFFSET(inode_size);
134 err = nilfs_cpfile_read(sb, checkpoint_size, rawi, &nilfs->ns_cpfile);
135 if (err)
136 goto failed_dat;
137
138 rawi = (void *)bh_sr->b_data + NILFS_SR_SUFILE_OFFSET(inode_size);
139 err = nilfs_sufile_read(sb, segment_usage_size, rawi,
140 &nilfs->ns_sufile);
141 if (err)
142 goto failed_cpfile;
143
144 raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
145 nilfs->ns_nongc_ctime = le64_to_cpu(raw_sr->sr_nongc_ctime);
146
147 failed:
148 brelse(bh_sr);
149 return err;
150
151 failed_cpfile:
152 iput(nilfs->ns_cpfile);
153
154 failed_dat:
155 iput(nilfs->ns_dat);
156 goto failed;
157}
158
159static void nilfs_init_recovery_info(struct nilfs_recovery_info *ri)
160{
161 memset(ri, 0, sizeof(*ri));
162 INIT_LIST_HEAD(&ri->ri_used_segments);
163}
164
165static void nilfs_clear_recovery_info(struct nilfs_recovery_info *ri)
166{
167 nilfs_dispose_segment_list(&ri->ri_used_segments);
168}
169
170/**
171 * nilfs_store_log_cursor - load log cursor from a super block
172 * @nilfs: nilfs object
173 * @sbp: buffer storing super block to be read
174 *
175 * nilfs_store_log_cursor() reads the last position of the log
176 * containing a super root from a given super block, and initializes
177 * relevant information on the nilfs object preparatory for log
178 * scanning and recovery.
179 */
180static int nilfs_store_log_cursor(struct the_nilfs *nilfs,
181 struct nilfs_super_block *sbp)
182{
183 int ret = 0;
184
185 nilfs->ns_last_pseg = le64_to_cpu(sbp->s_last_pseg);
186 nilfs->ns_last_cno = le64_to_cpu(sbp->s_last_cno);
187 nilfs->ns_last_seq = le64_to_cpu(sbp->s_last_seq);
188
189 nilfs->ns_prev_seq = nilfs->ns_last_seq;
190 nilfs->ns_seg_seq = nilfs->ns_last_seq;
191 nilfs->ns_segnum =
192 nilfs_get_segnum_of_block(nilfs, nilfs->ns_last_pseg);
193 nilfs->ns_cno = nilfs->ns_last_cno + 1;
194 if (nilfs->ns_segnum >= nilfs->ns_nsegments) {
195 nilfs_msg(nilfs->ns_sb, KERN_ERR,
196 "pointed segment number is out of range: segnum=%llu, nsegments=%lu",
197 (unsigned long long)nilfs->ns_segnum,
198 nilfs->ns_nsegments);
199 ret = -EINVAL;
200 }
201 return ret;
202}
203
204/**
205 * load_nilfs - load and recover the nilfs
206 * @nilfs: the_nilfs structure to be released
207 * @sb: super block isntance used to recover past segment
208 *
209 * load_nilfs() searches and load the latest super root,
210 * attaches the last segment, and does recovery if needed.
211 * The caller must call this exclusively for simultaneous mounts.
212 */
213int load_nilfs(struct the_nilfs *nilfs, struct super_block *sb)
214{
215 struct nilfs_recovery_info ri;
216 unsigned int s_flags = sb->s_flags;
217 int really_read_only = bdev_read_only(nilfs->ns_bdev);
218 int valid_fs = nilfs_valid_fs(nilfs);
219 int err;
220
221 if (!valid_fs) {
222 nilfs_msg(sb, KERN_WARNING, "mounting unchecked fs");
223 if (s_flags & SB_RDONLY) {
224 nilfs_msg(sb, KERN_INFO,
225 "recovery required for readonly filesystem");
226 nilfs_msg(sb, KERN_INFO,
227 "write access will be enabled during recovery");
228 }
229 }
230
231 nilfs_init_recovery_info(&ri);
232
233 err = nilfs_search_super_root(nilfs, &ri);
234 if (unlikely(err)) {
235 struct nilfs_super_block **sbp = nilfs->ns_sbp;
236 int blocksize;
237
238 if (err != -EINVAL)
239 goto scan_error;
240
241 if (!nilfs_valid_sb(sbp[1])) {
242 nilfs_msg(sb, KERN_WARNING,
243 "unable to fall back to spare super block");
244 goto scan_error;
245 }
246 nilfs_msg(sb, KERN_INFO,
247 "trying rollback from an earlier position");
248
249 /*
250 * restore super block with its spare and reconfigure
251 * relevant states of the nilfs object.
252 */
253 memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
254 nilfs->ns_crc_seed = le32_to_cpu(sbp[0]->s_crc_seed);
255 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime);
256
257 /* verify consistency between two super blocks */
258 blocksize = BLOCK_SIZE << le32_to_cpu(sbp[0]->s_log_block_size);
259 if (blocksize != nilfs->ns_blocksize) {
260 nilfs_msg(sb, KERN_WARNING,
261 "blocksize differs between two super blocks (%d != %d)",
262 blocksize, nilfs->ns_blocksize);
263 goto scan_error;
264 }
265
266 err = nilfs_store_log_cursor(nilfs, sbp[0]);
267 if (err)
268 goto scan_error;
269
270 /* drop clean flag to allow roll-forward and recovery */
271 nilfs->ns_mount_state &= ~NILFS_VALID_FS;
272 valid_fs = 0;
273
274 err = nilfs_search_super_root(nilfs, &ri);
275 if (err)
276 goto scan_error;
277 }
278
279 err = nilfs_load_super_root(nilfs, sb, ri.ri_super_root);
280 if (unlikely(err)) {
281 nilfs_msg(sb, KERN_ERR, "error %d while loading super root",
282 err);
283 goto failed;
284 }
285
286 if (valid_fs)
287 goto skip_recovery;
288
289 if (s_flags & SB_RDONLY) {
290 __u64 features;
291
292 if (nilfs_test_opt(nilfs, NORECOVERY)) {
293 nilfs_msg(sb, KERN_INFO,
294 "norecovery option specified, skipping roll-forward recovery");
295 goto skip_recovery;
296 }
297 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
298 ~NILFS_FEATURE_COMPAT_RO_SUPP;
299 if (features) {
300 nilfs_msg(sb, KERN_ERR,
301 "couldn't proceed with recovery because of unsupported optional features (%llx)",
302 (unsigned long long)features);
303 err = -EROFS;
304 goto failed_unload;
305 }
306 if (really_read_only) {
307 nilfs_msg(sb, KERN_ERR,
308 "write access unavailable, cannot proceed");
309 err = -EROFS;
310 goto failed_unload;
311 }
312 sb->s_flags &= ~SB_RDONLY;
313 } else if (nilfs_test_opt(nilfs, NORECOVERY)) {
314 nilfs_msg(sb, KERN_ERR,
315 "recovery cancelled because norecovery option was specified for a read/write mount");
316 err = -EINVAL;
317 goto failed_unload;
318 }
319
320 err = nilfs_salvage_orphan_logs(nilfs, sb, &ri);
321 if (err)
322 goto failed_unload;
323
324 down_write(&nilfs->ns_sem);
325 nilfs->ns_mount_state |= NILFS_VALID_FS; /* set "clean" flag */
326 err = nilfs_cleanup_super(sb);
327 up_write(&nilfs->ns_sem);
328
329 if (err) {
330 nilfs_msg(sb, KERN_ERR,
331 "error %d updating super block. recovery unfinished.",
332 err);
333 goto failed_unload;
334 }
335 nilfs_msg(sb, KERN_INFO, "recovery complete");
336
337 skip_recovery:
338 nilfs_clear_recovery_info(&ri);
339 sb->s_flags = s_flags;
340 return 0;
341
342 scan_error:
343 nilfs_msg(sb, KERN_ERR, "error %d while searching super root", err);
344 goto failed;
345
346 failed_unload:
347 iput(nilfs->ns_cpfile);
348 iput(nilfs->ns_sufile);
349 iput(nilfs->ns_dat);
350
351 failed:
352 nilfs_clear_recovery_info(&ri);
353 sb->s_flags = s_flags;
354 return err;
355}
356
357static unsigned long long nilfs_max_size(unsigned int blkbits)
358{
359 unsigned int max_bits;
360 unsigned long long res = MAX_LFS_FILESIZE; /* page cache limit */
361
362 max_bits = blkbits + NILFS_BMAP_KEY_BIT; /* bmap size limit */
363 if (max_bits < 64)
364 res = min_t(unsigned long long, res, (1ULL << max_bits) - 1);
365 return res;
366}
367
368/**
369 * nilfs_nrsvsegs - calculate the number of reserved segments
370 * @nilfs: nilfs object
371 * @nsegs: total number of segments
372 */
373unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs)
374{
375 return max_t(unsigned long, NILFS_MIN_NRSVSEGS,
376 DIV_ROUND_UP(nsegs * nilfs->ns_r_segments_percentage,
377 100));
378}
379
380void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs)
381{
382 nilfs->ns_nsegments = nsegs;
383 nilfs->ns_nrsvsegs = nilfs_nrsvsegs(nilfs, nsegs);
384}
385
386static int nilfs_store_disk_layout(struct the_nilfs *nilfs,
387 struct nilfs_super_block *sbp)
388{
389 if (le32_to_cpu(sbp->s_rev_level) < NILFS_MIN_SUPP_REV) {
390 nilfs_msg(nilfs->ns_sb, KERN_ERR,
391 "unsupported revision (superblock rev.=%d.%d, current rev.=%d.%d). Please check the version of mkfs.nilfs(2).",
392 le32_to_cpu(sbp->s_rev_level),
393 le16_to_cpu(sbp->s_minor_rev_level),
394 NILFS_CURRENT_REV, NILFS_MINOR_REV);
395 return -EINVAL;
396 }
397 nilfs->ns_sbsize = le16_to_cpu(sbp->s_bytes);
398 if (nilfs->ns_sbsize > BLOCK_SIZE)
399 return -EINVAL;
400
401 nilfs->ns_inode_size = le16_to_cpu(sbp->s_inode_size);
402 if (nilfs->ns_inode_size > nilfs->ns_blocksize) {
403 nilfs_msg(nilfs->ns_sb, KERN_ERR,
404 "too large inode size: %d bytes",
405 nilfs->ns_inode_size);
406 return -EINVAL;
407 } else if (nilfs->ns_inode_size < NILFS_MIN_INODE_SIZE) {
408 nilfs_msg(nilfs->ns_sb, KERN_ERR,
409 "too small inode size: %d bytes",
410 nilfs->ns_inode_size);
411 return -EINVAL;
412 }
413
414 nilfs->ns_first_ino = le32_to_cpu(sbp->s_first_ino);
415
416 nilfs->ns_blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment);
417 if (nilfs->ns_blocks_per_segment < NILFS_SEG_MIN_BLOCKS) {
418 nilfs_msg(nilfs->ns_sb, KERN_ERR,
419 "too short segment: %lu blocks",
420 nilfs->ns_blocks_per_segment);
421 return -EINVAL;
422 }
423
424 nilfs->ns_first_data_block = le64_to_cpu(sbp->s_first_data_block);
425 nilfs->ns_r_segments_percentage =
426 le32_to_cpu(sbp->s_r_segments_percentage);
427 if (nilfs->ns_r_segments_percentage < 1 ||
428 nilfs->ns_r_segments_percentage > 99) {
429 nilfs_msg(nilfs->ns_sb, KERN_ERR,
430 "invalid reserved segments percentage: %lu",
431 nilfs->ns_r_segments_percentage);
432 return -EINVAL;
433 }
434
435 nilfs_set_nsegments(nilfs, le64_to_cpu(sbp->s_nsegments));
436 nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed);
437 return 0;
438}
439
440static int nilfs_valid_sb(struct nilfs_super_block *sbp)
441{
442 static unsigned char sum[4];
443 const int sumoff = offsetof(struct nilfs_super_block, s_sum);
444 size_t bytes;
445 u32 crc;
446
447 if (!sbp || le16_to_cpu(sbp->s_magic) != NILFS_SUPER_MAGIC)
448 return 0;
449 bytes = le16_to_cpu(sbp->s_bytes);
450 if (bytes < sumoff + 4 || bytes > BLOCK_SIZE)
451 return 0;
452 crc = crc32_le(le32_to_cpu(sbp->s_crc_seed), (unsigned char *)sbp,
453 sumoff);
454 crc = crc32_le(crc, sum, 4);
455 crc = crc32_le(crc, (unsigned char *)sbp + sumoff + 4,
456 bytes - sumoff - 4);
457 return crc == le32_to_cpu(sbp->s_sum);
458}
459
460static int nilfs_sb2_bad_offset(struct nilfs_super_block *sbp, u64 offset)
461{
462 return offset < ((le64_to_cpu(sbp->s_nsegments) *
463 le32_to_cpu(sbp->s_blocks_per_segment)) <<
464 (le32_to_cpu(sbp->s_log_block_size) + 10));
465}
466
467static void nilfs_release_super_block(struct the_nilfs *nilfs)
468{
469 int i;
470
471 for (i = 0; i < 2; i++) {
472 if (nilfs->ns_sbp[i]) {
473 brelse(nilfs->ns_sbh[i]);
474 nilfs->ns_sbh[i] = NULL;
475 nilfs->ns_sbp[i] = NULL;
476 }
477 }
478}
479
480void nilfs_fall_back_super_block(struct the_nilfs *nilfs)
481{
482 brelse(nilfs->ns_sbh[0]);
483 nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
484 nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
485 nilfs->ns_sbh[1] = NULL;
486 nilfs->ns_sbp[1] = NULL;
487}
488
489void nilfs_swap_super_block(struct the_nilfs *nilfs)
490{
491 struct buffer_head *tsbh = nilfs->ns_sbh[0];
492 struct nilfs_super_block *tsbp = nilfs->ns_sbp[0];
493
494 nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
495 nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
496 nilfs->ns_sbh[1] = tsbh;
497 nilfs->ns_sbp[1] = tsbp;
498}
499
500static int nilfs_load_super_block(struct the_nilfs *nilfs,
501 struct super_block *sb, int blocksize,
502 struct nilfs_super_block **sbpp)
503{
504 struct nilfs_super_block **sbp = nilfs->ns_sbp;
505 struct buffer_head **sbh = nilfs->ns_sbh;
506 u64 sb2off = NILFS_SB2_OFFSET_BYTES(nilfs->ns_bdev->bd_inode->i_size);
507 int valid[2], swp = 0;
508
509 sbp[0] = nilfs_read_super_block(sb, NILFS_SB_OFFSET_BYTES, blocksize,
510 &sbh[0]);
511 sbp[1] = nilfs_read_super_block(sb, sb2off, blocksize, &sbh[1]);
512
513 if (!sbp[0]) {
514 if (!sbp[1]) {
515 nilfs_msg(sb, KERN_ERR, "unable to read superblock");
516 return -EIO;
517 }
518 nilfs_msg(sb, KERN_WARNING,
519 "unable to read primary superblock (blocksize = %d)",
520 blocksize);
521 } else if (!sbp[1]) {
522 nilfs_msg(sb, KERN_WARNING,
523 "unable to read secondary superblock (blocksize = %d)",
524 blocksize);
525 }
526
527 /*
528 * Compare two super blocks and set 1 in swp if the secondary
529 * super block is valid and newer. Otherwise, set 0 in swp.
530 */
531 valid[0] = nilfs_valid_sb(sbp[0]);
532 valid[1] = nilfs_valid_sb(sbp[1]);
533 swp = valid[1] && (!valid[0] ||
534 le64_to_cpu(sbp[1]->s_last_cno) >
535 le64_to_cpu(sbp[0]->s_last_cno));
536
537 if (valid[swp] && nilfs_sb2_bad_offset(sbp[swp], sb2off)) {
538 brelse(sbh[1]);
539 sbh[1] = NULL;
540 sbp[1] = NULL;
541 valid[1] = 0;
542 swp = 0;
543 }
544 if (!valid[swp]) {
545 nilfs_release_super_block(nilfs);
546 nilfs_msg(sb, KERN_ERR, "couldn't find nilfs on the device");
547 return -EINVAL;
548 }
549
550 if (!valid[!swp])
551 nilfs_msg(sb, KERN_WARNING,
552 "broken superblock, retrying with spare superblock (blocksize = %d)",
553 blocksize);
554 if (swp)
555 nilfs_swap_super_block(nilfs);
556
557 nilfs->ns_sbwcount = 0;
558 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime);
559 nilfs->ns_prot_seq = le64_to_cpu(sbp[valid[1] & !swp]->s_last_seq);
560 *sbpp = sbp[0];
561 return 0;
562}
563
564/**
565 * init_nilfs - initialize a NILFS instance.
566 * @nilfs: the_nilfs structure
567 * @sb: super block
568 * @data: mount options
569 *
570 * init_nilfs() performs common initialization per block device (e.g.
571 * reading the super block, getting disk layout information, initializing
572 * shared fields in the_nilfs).
573 *
574 * Return Value: On success, 0 is returned. On error, a negative error
575 * code is returned.
576 */
577int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data)
578{
579 struct nilfs_super_block *sbp;
580 int blocksize;
581 int err;
582
583 down_write(&nilfs->ns_sem);
584
585 blocksize = sb_min_blocksize(sb, NILFS_MIN_BLOCK_SIZE);
586 if (!blocksize) {
587 nilfs_msg(sb, KERN_ERR, "unable to set blocksize");
588 err = -EINVAL;
589 goto out;
590 }
591 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
592 if (err)
593 goto out;
594
595 err = nilfs_store_magic_and_option(sb, sbp, data);
596 if (err)
597 goto failed_sbh;
598
599 err = nilfs_check_feature_compatibility(sb, sbp);
600 if (err)
601 goto failed_sbh;
602
603 blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size);
604 if (blocksize < NILFS_MIN_BLOCK_SIZE ||
605 blocksize > NILFS_MAX_BLOCK_SIZE) {
606 nilfs_msg(sb, KERN_ERR,
607 "couldn't mount because of unsupported filesystem blocksize %d",
608 blocksize);
609 err = -EINVAL;
610 goto failed_sbh;
611 }
612 if (sb->s_blocksize != blocksize) {
613 int hw_blocksize = bdev_logical_block_size(sb->s_bdev);
614
615 if (blocksize < hw_blocksize) {
616 nilfs_msg(sb, KERN_ERR,
617 "blocksize %d too small for device (sector-size = %d)",
618 blocksize, hw_blocksize);
619 err = -EINVAL;
620 goto failed_sbh;
621 }
622 nilfs_release_super_block(nilfs);
623 sb_set_blocksize(sb, blocksize);
624
625 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
626 if (err)
627 goto out;
628 /*
629 * Not to failed_sbh; sbh is released automatically
630 * when reloading fails.
631 */
632 }
633 nilfs->ns_blocksize_bits = sb->s_blocksize_bits;
634 nilfs->ns_blocksize = blocksize;
635
636 get_random_bytes(&nilfs->ns_next_generation,
637 sizeof(nilfs->ns_next_generation));
638
639 err = nilfs_store_disk_layout(nilfs, sbp);
640 if (err)
641 goto failed_sbh;
642
643 sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits);
644
645 nilfs->ns_mount_state = le16_to_cpu(sbp->s_state);
646
647 err = nilfs_store_log_cursor(nilfs, sbp);
648 if (err)
649 goto failed_sbh;
650
651 err = nilfs_sysfs_create_device_group(sb);
652 if (err)
653 goto failed_sbh;
654
655 set_nilfs_init(nilfs);
656 err = 0;
657 out:
658 up_write(&nilfs->ns_sem);
659 return err;
660
661 failed_sbh:
662 nilfs_release_super_block(nilfs);
663 goto out;
664}
665
666int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump,
667 size_t nsegs)
668{
669 sector_t seg_start, seg_end;
670 sector_t start = 0, nblocks = 0;
671 unsigned int sects_per_block;
672 __u64 *sn;
673 int ret = 0;
674
675 sects_per_block = (1 << nilfs->ns_blocksize_bits) /
676 bdev_logical_block_size(nilfs->ns_bdev);
677 for (sn = segnump; sn < segnump + nsegs; sn++) {
678 nilfs_get_segment_range(nilfs, *sn, &seg_start, &seg_end);
679
680 if (!nblocks) {
681 start = seg_start;
682 nblocks = seg_end - seg_start + 1;
683 } else if (start + nblocks == seg_start) {
684 nblocks += seg_end - seg_start + 1;
685 } else {
686 ret = blkdev_issue_discard(nilfs->ns_bdev,
687 start * sects_per_block,
688 nblocks * sects_per_block,
689 GFP_NOFS, 0);
690 if (ret < 0)
691 return ret;
692 nblocks = 0;
693 }
694 }
695 if (nblocks)
696 ret = blkdev_issue_discard(nilfs->ns_bdev,
697 start * sects_per_block,
698 nblocks * sects_per_block,
699 GFP_NOFS, 0);
700 return ret;
701}
702
703int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks)
704{
705 unsigned long ncleansegs;
706
707 down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
708 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
709 up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
710 *nblocks = (sector_t)ncleansegs * nilfs->ns_blocks_per_segment;
711 return 0;
712}
713
714int nilfs_near_disk_full(struct the_nilfs *nilfs)
715{
716 unsigned long ncleansegs, nincsegs;
717
718 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
719 nincsegs = atomic_read(&nilfs->ns_ndirtyblks) /
720 nilfs->ns_blocks_per_segment + 1;
721
722 return ncleansegs <= nilfs->ns_nrsvsegs + nincsegs;
723}
724
725struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno)
726{
727 struct rb_node *n;
728 struct nilfs_root *root;
729
730 spin_lock(&nilfs->ns_cptree_lock);
731 n = nilfs->ns_cptree.rb_node;
732 while (n) {
733 root = rb_entry(n, struct nilfs_root, rb_node);
734
735 if (cno < root->cno) {
736 n = n->rb_left;
737 } else if (cno > root->cno) {
738 n = n->rb_right;
739 } else {
740 refcount_inc(&root->count);
741 spin_unlock(&nilfs->ns_cptree_lock);
742 return root;
743 }
744 }
745 spin_unlock(&nilfs->ns_cptree_lock);
746
747 return NULL;
748}
749
750struct nilfs_root *
751nilfs_find_or_create_root(struct the_nilfs *nilfs, __u64 cno)
752{
753 struct rb_node **p, *parent;
754 struct nilfs_root *root, *new;
755 int err;
756
757 root = nilfs_lookup_root(nilfs, cno);
758 if (root)
759 return root;
760
761 new = kzalloc(sizeof(*root), GFP_KERNEL);
762 if (!new)
763 return NULL;
764
765 spin_lock(&nilfs->ns_cptree_lock);
766
767 p = &nilfs->ns_cptree.rb_node;
768 parent = NULL;
769
770 while (*p) {
771 parent = *p;
772 root = rb_entry(parent, struct nilfs_root, rb_node);
773
774 if (cno < root->cno) {
775 p = &(*p)->rb_left;
776 } else if (cno > root->cno) {
777 p = &(*p)->rb_right;
778 } else {
779 refcount_inc(&root->count);
780 spin_unlock(&nilfs->ns_cptree_lock);
781 kfree(new);
782 return root;
783 }
784 }
785
786 new->cno = cno;
787 new->ifile = NULL;
788 new->nilfs = nilfs;
789 refcount_set(&new->count, 1);
790 atomic64_set(&new->inodes_count, 0);
791 atomic64_set(&new->blocks_count, 0);
792
793 rb_link_node(&new->rb_node, parent, p);
794 rb_insert_color(&new->rb_node, &nilfs->ns_cptree);
795
796 spin_unlock(&nilfs->ns_cptree_lock);
797
798 err = nilfs_sysfs_create_snapshot_group(new);
799 if (err) {
800 kfree(new);
801 new = NULL;
802 }
803
804 return new;
805}
806
807void nilfs_put_root(struct nilfs_root *root)
808{
809 if (refcount_dec_and_test(&root->count)) {
810 struct the_nilfs *nilfs = root->nilfs;
811
812 nilfs_sysfs_delete_snapshot_group(root);
813
814 spin_lock(&nilfs->ns_cptree_lock);
815 rb_erase(&root->rb_node, &nilfs->ns_cptree);
816 spin_unlock(&nilfs->ns_cptree_lock);
817 iput(root->ifile);
818
819 kfree(root);
820 }
821}
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * the_nilfs shared structure.
4 *
5 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
6 *
7 * Written by Ryusuke Konishi.
8 *
9 */
10
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>
18#include "nilfs.h"
19#include "segment.h"
20#include "alloc.h"
21#include "cpfile.h"
22#include "sufile.h"
23#include "dat.h"
24#include "segbuf.h"
25
26
27static int nilfs_valid_sb(struct nilfs_super_block *sbp);
28
29void nilfs_set_last_segment(struct the_nilfs *nilfs,
30 sector_t start_blocknr, u64 seq, __u64 cno)
31{
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;
36
37 if (!nilfs_sb_dirty(nilfs)) {
38 if (nilfs->ns_prev_seq == nilfs->ns_last_seq)
39 goto stay_cursor;
40
41 set_nilfs_sb_dirty(nilfs);
42 }
43 nilfs->ns_prev_seq = nilfs->ns_last_seq;
44
45 stay_cursor:
46 spin_unlock(&nilfs->ns_last_segment_lock);
47}
48
49/**
50 * alloc_nilfs - allocate a nilfs object
51 * @sb: super block instance
52 *
53 * Return Value: On success, pointer to the_nilfs is returned.
54 * On error, NULL is returned.
55 */
56struct the_nilfs *alloc_nilfs(struct super_block *sb)
57{
58 struct the_nilfs *nilfs;
59
60 nilfs = kzalloc(sizeof(*nilfs), GFP_KERNEL);
61 if (!nilfs)
62 return NULL;
63
64 nilfs->ns_sb = sb;
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;
78
79 return nilfs;
80}
81
82/**
83 * destroy_nilfs - destroy nilfs object
84 * @nilfs: nilfs object to be released
85 */
86void destroy_nilfs(struct the_nilfs *nilfs)
87{
88 might_sleep();
89 if (nilfs_init(nilfs)) {
90 nilfs_sysfs_delete_device_group(nilfs);
91 brelse(nilfs->ns_sbh[0]);
92 brelse(nilfs->ns_sbh[1]);
93 }
94 kfree(nilfs);
95}
96
97static int nilfs_load_super_root(struct the_nilfs *nilfs,
98 struct super_block *sb, sector_t sr_block)
99{
100 struct buffer_head *bh_sr;
101 struct nilfs_super_root *raw_sr;
102 struct nilfs_super_block **sbp = nilfs->ns_sbp;
103 struct nilfs_inode *rawi;
104 unsigned int dat_entry_size, segment_usage_size, checkpoint_size;
105 unsigned int inode_size;
106 int err;
107
108 err = nilfs_read_super_root_block(nilfs, sr_block, &bh_sr, 1);
109 if (unlikely(err))
110 return err;
111
112 down_read(&nilfs->ns_sem);
113 dat_entry_size = le16_to_cpu(sbp[0]->s_dat_entry_size);
114 checkpoint_size = le16_to_cpu(sbp[0]->s_checkpoint_size);
115 segment_usage_size = le16_to_cpu(sbp[0]->s_segment_usage_size);
116 up_read(&nilfs->ns_sem);
117
118 inode_size = nilfs->ns_inode_size;
119
120 rawi = (void *)bh_sr->b_data + NILFS_SR_DAT_OFFSET(inode_size);
121 err = nilfs_dat_read(sb, dat_entry_size, rawi, &nilfs->ns_dat);
122 if (err)
123 goto failed;
124
125 rawi = (void *)bh_sr->b_data + NILFS_SR_CPFILE_OFFSET(inode_size);
126 err = nilfs_cpfile_read(sb, checkpoint_size, rawi, &nilfs->ns_cpfile);
127 if (err)
128 goto failed_dat;
129
130 rawi = (void *)bh_sr->b_data + NILFS_SR_SUFILE_OFFSET(inode_size);
131 err = nilfs_sufile_read(sb, segment_usage_size, rawi,
132 &nilfs->ns_sufile);
133 if (err)
134 goto failed_cpfile;
135
136 raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
137 nilfs->ns_nongc_ctime = le64_to_cpu(raw_sr->sr_nongc_ctime);
138
139 failed:
140 brelse(bh_sr);
141 return err;
142
143 failed_cpfile:
144 iput(nilfs->ns_cpfile);
145
146 failed_dat:
147 iput(nilfs->ns_dat);
148 goto failed;
149}
150
151static void nilfs_init_recovery_info(struct nilfs_recovery_info *ri)
152{
153 memset(ri, 0, sizeof(*ri));
154 INIT_LIST_HEAD(&ri->ri_used_segments);
155}
156
157static void nilfs_clear_recovery_info(struct nilfs_recovery_info *ri)
158{
159 nilfs_dispose_segment_list(&ri->ri_used_segments);
160}
161
162/**
163 * nilfs_store_log_cursor - load log cursor from a super block
164 * @nilfs: nilfs object
165 * @sbp: buffer storing super block to be read
166 *
167 * nilfs_store_log_cursor() reads the last position of the log
168 * containing a super root from a given super block, and initializes
169 * relevant information on the nilfs object preparatory for log
170 * scanning and recovery.
171 */
172static int nilfs_store_log_cursor(struct the_nilfs *nilfs,
173 struct nilfs_super_block *sbp)
174{
175 int ret = 0;
176
177 nilfs->ns_last_pseg = le64_to_cpu(sbp->s_last_pseg);
178 nilfs->ns_last_cno = le64_to_cpu(sbp->s_last_cno);
179 nilfs->ns_last_seq = le64_to_cpu(sbp->s_last_seq);
180
181 nilfs->ns_prev_seq = nilfs->ns_last_seq;
182 nilfs->ns_seg_seq = nilfs->ns_last_seq;
183 nilfs->ns_segnum =
184 nilfs_get_segnum_of_block(nilfs, nilfs->ns_last_pseg);
185 nilfs->ns_cno = nilfs->ns_last_cno + 1;
186 if (nilfs->ns_segnum >= nilfs->ns_nsegments) {
187 nilfs_err(nilfs->ns_sb,
188 "pointed segment number is out of range: segnum=%llu, nsegments=%lu",
189 (unsigned long long)nilfs->ns_segnum,
190 nilfs->ns_nsegments);
191 ret = -EINVAL;
192 }
193 return ret;
194}
195
196/**
197 * nilfs_get_blocksize - get block size from raw superblock data
198 * @sb: super block instance
199 * @sbp: superblock raw data buffer
200 * @blocksize: place to store block size
201 *
202 * nilfs_get_blocksize() calculates the block size from the block size
203 * exponent information written in @sbp and stores it in @blocksize,
204 * or aborts with an error message if it's too large.
205 *
206 * Return Value: On success, 0 is returned. If the block size is too
207 * large, -EINVAL is returned.
208 */
209static int nilfs_get_blocksize(struct super_block *sb,
210 struct nilfs_super_block *sbp, int *blocksize)
211{
212 unsigned int shift_bits = le32_to_cpu(sbp->s_log_block_size);
213
214 if (unlikely(shift_bits >
215 ilog2(NILFS_MAX_BLOCK_SIZE) - BLOCK_SIZE_BITS)) {
216 nilfs_err(sb, "too large filesystem blocksize: 2 ^ %u KiB",
217 shift_bits);
218 return -EINVAL;
219 }
220 *blocksize = BLOCK_SIZE << shift_bits;
221 return 0;
222}
223
224/**
225 * load_nilfs - load and recover the nilfs
226 * @nilfs: the_nilfs structure to be released
227 * @sb: super block instance used to recover past segment
228 *
229 * load_nilfs() searches and load the latest super root,
230 * attaches the last segment, and does recovery if needed.
231 * The caller must call this exclusively for simultaneous mounts.
232 */
233int load_nilfs(struct the_nilfs *nilfs, struct super_block *sb)
234{
235 struct nilfs_recovery_info ri;
236 unsigned int s_flags = sb->s_flags;
237 int really_read_only = bdev_read_only(nilfs->ns_bdev);
238 int valid_fs = nilfs_valid_fs(nilfs);
239 int err;
240
241 if (!valid_fs) {
242 nilfs_warn(sb, "mounting unchecked fs");
243 if (s_flags & SB_RDONLY) {
244 nilfs_info(sb,
245 "recovery required for readonly filesystem");
246 nilfs_info(sb,
247 "write access will be enabled during recovery");
248 }
249 }
250
251 nilfs_init_recovery_info(&ri);
252
253 err = nilfs_search_super_root(nilfs, &ri);
254 if (unlikely(err)) {
255 struct nilfs_super_block **sbp = nilfs->ns_sbp;
256 int blocksize;
257
258 if (err != -EINVAL)
259 goto scan_error;
260
261 if (!nilfs_valid_sb(sbp[1])) {
262 nilfs_warn(sb,
263 "unable to fall back to spare super block");
264 goto scan_error;
265 }
266 nilfs_info(sb, "trying rollback from an earlier position");
267
268 /*
269 * restore super block with its spare and reconfigure
270 * relevant states of the nilfs object.
271 */
272 memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
273 nilfs->ns_crc_seed = le32_to_cpu(sbp[0]->s_crc_seed);
274 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime);
275
276 /* verify consistency between two super blocks */
277 err = nilfs_get_blocksize(sb, sbp[0], &blocksize);
278 if (err)
279 goto scan_error;
280
281 if (blocksize != nilfs->ns_blocksize) {
282 nilfs_warn(sb,
283 "blocksize differs between two super blocks (%d != %d)",
284 blocksize, nilfs->ns_blocksize);
285 err = -EINVAL;
286 goto scan_error;
287 }
288
289 err = nilfs_store_log_cursor(nilfs, sbp[0]);
290 if (err)
291 goto scan_error;
292
293 /* drop clean flag to allow roll-forward and recovery */
294 nilfs->ns_mount_state &= ~NILFS_VALID_FS;
295 valid_fs = 0;
296
297 err = nilfs_search_super_root(nilfs, &ri);
298 if (err)
299 goto scan_error;
300 }
301
302 err = nilfs_load_super_root(nilfs, sb, ri.ri_super_root);
303 if (unlikely(err)) {
304 nilfs_err(sb, "error %d while loading super root", err);
305 goto failed;
306 }
307
308 if (valid_fs)
309 goto skip_recovery;
310
311 if (s_flags & SB_RDONLY) {
312 __u64 features;
313
314 if (nilfs_test_opt(nilfs, NORECOVERY)) {
315 nilfs_info(sb,
316 "norecovery option specified, skipping roll-forward recovery");
317 goto skip_recovery;
318 }
319 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
320 ~NILFS_FEATURE_COMPAT_RO_SUPP;
321 if (features) {
322 nilfs_err(sb,
323 "couldn't proceed with recovery because of unsupported optional features (%llx)",
324 (unsigned long long)features);
325 err = -EROFS;
326 goto failed_unload;
327 }
328 if (really_read_only) {
329 nilfs_err(sb,
330 "write access unavailable, cannot proceed");
331 err = -EROFS;
332 goto failed_unload;
333 }
334 sb->s_flags &= ~SB_RDONLY;
335 } else if (nilfs_test_opt(nilfs, NORECOVERY)) {
336 nilfs_err(sb,
337 "recovery cancelled because norecovery option was specified for a read/write mount");
338 err = -EINVAL;
339 goto failed_unload;
340 }
341
342 err = nilfs_salvage_orphan_logs(nilfs, sb, &ri);
343 if (err)
344 goto failed_unload;
345
346 down_write(&nilfs->ns_sem);
347 nilfs->ns_mount_state |= NILFS_VALID_FS; /* set "clean" flag */
348 err = nilfs_cleanup_super(sb);
349 up_write(&nilfs->ns_sem);
350
351 if (err) {
352 nilfs_err(sb,
353 "error %d updating super block. recovery unfinished.",
354 err);
355 goto failed_unload;
356 }
357 nilfs_info(sb, "recovery complete");
358
359 skip_recovery:
360 nilfs_clear_recovery_info(&ri);
361 sb->s_flags = s_flags;
362 return 0;
363
364 scan_error:
365 nilfs_err(sb, "error %d while searching super root", err);
366 goto failed;
367
368 failed_unload:
369 iput(nilfs->ns_cpfile);
370 iput(nilfs->ns_sufile);
371 iput(nilfs->ns_dat);
372
373 failed:
374 nilfs_clear_recovery_info(&ri);
375 sb->s_flags = s_flags;
376 return err;
377}
378
379static unsigned long long nilfs_max_size(unsigned int blkbits)
380{
381 unsigned int max_bits;
382 unsigned long long res = MAX_LFS_FILESIZE; /* page cache limit */
383
384 max_bits = blkbits + NILFS_BMAP_KEY_BIT; /* bmap size limit */
385 if (max_bits < 64)
386 res = min_t(unsigned long long, res, (1ULL << max_bits) - 1);
387 return res;
388}
389
390/**
391 * nilfs_nrsvsegs - calculate the number of reserved segments
392 * @nilfs: nilfs object
393 * @nsegs: total number of segments
394 */
395unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs)
396{
397 return max_t(unsigned long, NILFS_MIN_NRSVSEGS,
398 DIV_ROUND_UP(nsegs * nilfs->ns_r_segments_percentage,
399 100));
400}
401
402void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs)
403{
404 nilfs->ns_nsegments = nsegs;
405 nilfs->ns_nrsvsegs = nilfs_nrsvsegs(nilfs, nsegs);
406}
407
408static int nilfs_store_disk_layout(struct the_nilfs *nilfs,
409 struct nilfs_super_block *sbp)
410{
411 if (le32_to_cpu(sbp->s_rev_level) < NILFS_MIN_SUPP_REV) {
412 nilfs_err(nilfs->ns_sb,
413 "unsupported revision (superblock rev.=%d.%d, current rev.=%d.%d). Please check the version of mkfs.nilfs(2).",
414 le32_to_cpu(sbp->s_rev_level),
415 le16_to_cpu(sbp->s_minor_rev_level),
416 NILFS_CURRENT_REV, NILFS_MINOR_REV);
417 return -EINVAL;
418 }
419 nilfs->ns_sbsize = le16_to_cpu(sbp->s_bytes);
420 if (nilfs->ns_sbsize > BLOCK_SIZE)
421 return -EINVAL;
422
423 nilfs->ns_inode_size = le16_to_cpu(sbp->s_inode_size);
424 if (nilfs->ns_inode_size > nilfs->ns_blocksize) {
425 nilfs_err(nilfs->ns_sb, "too large inode size: %d bytes",
426 nilfs->ns_inode_size);
427 return -EINVAL;
428 } else if (nilfs->ns_inode_size < NILFS_MIN_INODE_SIZE) {
429 nilfs_err(nilfs->ns_sb, "too small inode size: %d bytes",
430 nilfs->ns_inode_size);
431 return -EINVAL;
432 }
433
434 nilfs->ns_first_ino = le32_to_cpu(sbp->s_first_ino);
435
436 nilfs->ns_blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment);
437 if (nilfs->ns_blocks_per_segment < NILFS_SEG_MIN_BLOCKS) {
438 nilfs_err(nilfs->ns_sb, "too short segment: %lu blocks",
439 nilfs->ns_blocks_per_segment);
440 return -EINVAL;
441 }
442
443 nilfs->ns_first_data_block = le64_to_cpu(sbp->s_first_data_block);
444 nilfs->ns_r_segments_percentage =
445 le32_to_cpu(sbp->s_r_segments_percentage);
446 if (nilfs->ns_r_segments_percentage < 1 ||
447 nilfs->ns_r_segments_percentage > 99) {
448 nilfs_err(nilfs->ns_sb,
449 "invalid reserved segments percentage: %lu",
450 nilfs->ns_r_segments_percentage);
451 return -EINVAL;
452 }
453
454 nilfs_set_nsegments(nilfs, le64_to_cpu(sbp->s_nsegments));
455 nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed);
456 return 0;
457}
458
459static int nilfs_valid_sb(struct nilfs_super_block *sbp)
460{
461 static unsigned char sum[4];
462 const int sumoff = offsetof(struct nilfs_super_block, s_sum);
463 size_t bytes;
464 u32 crc;
465
466 if (!sbp || le16_to_cpu(sbp->s_magic) != NILFS_SUPER_MAGIC)
467 return 0;
468 bytes = le16_to_cpu(sbp->s_bytes);
469 if (bytes < sumoff + 4 || bytes > BLOCK_SIZE)
470 return 0;
471 crc = crc32_le(le32_to_cpu(sbp->s_crc_seed), (unsigned char *)sbp,
472 sumoff);
473 crc = crc32_le(crc, sum, 4);
474 crc = crc32_le(crc, (unsigned char *)sbp + sumoff + 4,
475 bytes - sumoff - 4);
476 return crc == le32_to_cpu(sbp->s_sum);
477}
478
479/**
480 * nilfs_sb2_bad_offset - check the location of the second superblock
481 * @sbp: superblock raw data buffer
482 * @offset: byte offset of second superblock calculated from device size
483 *
484 * nilfs_sb2_bad_offset() checks if the position on the second
485 * superblock is valid or not based on the filesystem parameters
486 * stored in @sbp. If @offset points to a location within the segment
487 * area, or if the parameters themselves are not normal, it is
488 * determined to be invalid.
489 *
490 * Return Value: true if invalid, false if valid.
491 */
492static bool nilfs_sb2_bad_offset(struct nilfs_super_block *sbp, u64 offset)
493{
494 unsigned int shift_bits = le32_to_cpu(sbp->s_log_block_size);
495 u32 blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment);
496 u64 nsegments = le64_to_cpu(sbp->s_nsegments);
497 u64 index;
498
499 if (blocks_per_segment < NILFS_SEG_MIN_BLOCKS ||
500 shift_bits > ilog2(NILFS_MAX_BLOCK_SIZE) - BLOCK_SIZE_BITS)
501 return true;
502
503 index = offset >> (shift_bits + BLOCK_SIZE_BITS);
504 do_div(index, blocks_per_segment);
505 return index < nsegments;
506}
507
508static void nilfs_release_super_block(struct the_nilfs *nilfs)
509{
510 int i;
511
512 for (i = 0; i < 2; i++) {
513 if (nilfs->ns_sbp[i]) {
514 brelse(nilfs->ns_sbh[i]);
515 nilfs->ns_sbh[i] = NULL;
516 nilfs->ns_sbp[i] = NULL;
517 }
518 }
519}
520
521void nilfs_fall_back_super_block(struct the_nilfs *nilfs)
522{
523 brelse(nilfs->ns_sbh[0]);
524 nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
525 nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
526 nilfs->ns_sbh[1] = NULL;
527 nilfs->ns_sbp[1] = NULL;
528}
529
530void nilfs_swap_super_block(struct the_nilfs *nilfs)
531{
532 struct buffer_head *tsbh = nilfs->ns_sbh[0];
533 struct nilfs_super_block *tsbp = nilfs->ns_sbp[0];
534
535 nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
536 nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
537 nilfs->ns_sbh[1] = tsbh;
538 nilfs->ns_sbp[1] = tsbp;
539}
540
541static int nilfs_load_super_block(struct the_nilfs *nilfs,
542 struct super_block *sb, int blocksize,
543 struct nilfs_super_block **sbpp)
544{
545 struct nilfs_super_block **sbp = nilfs->ns_sbp;
546 struct buffer_head **sbh = nilfs->ns_sbh;
547 u64 sb2off, devsize = bdev_nr_bytes(nilfs->ns_bdev);
548 int valid[2], swp = 0;
549
550 if (devsize < NILFS_SEG_MIN_BLOCKS * NILFS_MIN_BLOCK_SIZE + 4096) {
551 nilfs_err(sb, "device size too small");
552 return -EINVAL;
553 }
554 sb2off = NILFS_SB2_OFFSET_BYTES(devsize);
555
556 sbp[0] = nilfs_read_super_block(sb, NILFS_SB_OFFSET_BYTES, blocksize,
557 &sbh[0]);
558 sbp[1] = nilfs_read_super_block(sb, sb2off, blocksize, &sbh[1]);
559
560 if (!sbp[0]) {
561 if (!sbp[1]) {
562 nilfs_err(sb, "unable to read superblock");
563 return -EIO;
564 }
565 nilfs_warn(sb,
566 "unable to read primary superblock (blocksize = %d)",
567 blocksize);
568 } else if (!sbp[1]) {
569 nilfs_warn(sb,
570 "unable to read secondary superblock (blocksize = %d)",
571 blocksize);
572 }
573
574 /*
575 * Compare two super blocks and set 1 in swp if the secondary
576 * super block is valid and newer. Otherwise, set 0 in swp.
577 */
578 valid[0] = nilfs_valid_sb(sbp[0]);
579 valid[1] = nilfs_valid_sb(sbp[1]);
580 swp = valid[1] && (!valid[0] ||
581 le64_to_cpu(sbp[1]->s_last_cno) >
582 le64_to_cpu(sbp[0]->s_last_cno));
583
584 if (valid[swp] && nilfs_sb2_bad_offset(sbp[swp], sb2off)) {
585 brelse(sbh[1]);
586 sbh[1] = NULL;
587 sbp[1] = NULL;
588 valid[1] = 0;
589 swp = 0;
590 }
591 if (!valid[swp]) {
592 nilfs_release_super_block(nilfs);
593 nilfs_err(sb, "couldn't find nilfs on the device");
594 return -EINVAL;
595 }
596
597 if (!valid[!swp])
598 nilfs_warn(sb,
599 "broken superblock, retrying with spare superblock (blocksize = %d)",
600 blocksize);
601 if (swp)
602 nilfs_swap_super_block(nilfs);
603
604 nilfs->ns_sbwcount = 0;
605 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime);
606 nilfs->ns_prot_seq = le64_to_cpu(sbp[valid[1] & !swp]->s_last_seq);
607 *sbpp = sbp[0];
608 return 0;
609}
610
611/**
612 * init_nilfs - initialize a NILFS instance.
613 * @nilfs: the_nilfs structure
614 * @sb: super block
615 * @data: mount options
616 *
617 * init_nilfs() performs common initialization per block device (e.g.
618 * reading the super block, getting disk layout information, initializing
619 * shared fields in the_nilfs).
620 *
621 * Return Value: On success, 0 is returned. On error, a negative error
622 * code is returned.
623 */
624int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data)
625{
626 struct nilfs_super_block *sbp;
627 int blocksize;
628 int err;
629
630 down_write(&nilfs->ns_sem);
631
632 blocksize = sb_min_blocksize(sb, NILFS_MIN_BLOCK_SIZE);
633 if (!blocksize) {
634 nilfs_err(sb, "unable to set blocksize");
635 err = -EINVAL;
636 goto out;
637 }
638 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
639 if (err)
640 goto out;
641
642 err = nilfs_store_magic_and_option(sb, sbp, data);
643 if (err)
644 goto failed_sbh;
645
646 err = nilfs_check_feature_compatibility(sb, sbp);
647 if (err)
648 goto failed_sbh;
649
650 err = nilfs_get_blocksize(sb, sbp, &blocksize);
651 if (err)
652 goto failed_sbh;
653
654 if (blocksize < NILFS_MIN_BLOCK_SIZE) {
655 nilfs_err(sb,
656 "couldn't mount because of unsupported filesystem blocksize %d",
657 blocksize);
658 err = -EINVAL;
659 goto failed_sbh;
660 }
661 if (sb->s_blocksize != blocksize) {
662 int hw_blocksize = bdev_logical_block_size(sb->s_bdev);
663
664 if (blocksize < hw_blocksize) {
665 nilfs_err(sb,
666 "blocksize %d too small for device (sector-size = %d)",
667 blocksize, hw_blocksize);
668 err = -EINVAL;
669 goto failed_sbh;
670 }
671 nilfs_release_super_block(nilfs);
672 sb_set_blocksize(sb, blocksize);
673
674 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
675 if (err)
676 goto out;
677 /*
678 * Not to failed_sbh; sbh is released automatically
679 * when reloading fails.
680 */
681 }
682 nilfs->ns_blocksize_bits = sb->s_blocksize_bits;
683 nilfs->ns_blocksize = blocksize;
684
685 get_random_bytes(&nilfs->ns_next_generation,
686 sizeof(nilfs->ns_next_generation));
687
688 err = nilfs_store_disk_layout(nilfs, sbp);
689 if (err)
690 goto failed_sbh;
691
692 sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits);
693
694 nilfs->ns_mount_state = le16_to_cpu(sbp->s_state);
695
696 err = nilfs_store_log_cursor(nilfs, sbp);
697 if (err)
698 goto failed_sbh;
699
700 err = nilfs_sysfs_create_device_group(sb);
701 if (err)
702 goto failed_sbh;
703
704 set_nilfs_init(nilfs);
705 err = 0;
706 out:
707 up_write(&nilfs->ns_sem);
708 return err;
709
710 failed_sbh:
711 nilfs_release_super_block(nilfs);
712 goto out;
713}
714
715int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump,
716 size_t nsegs)
717{
718 sector_t seg_start, seg_end;
719 sector_t start = 0, nblocks = 0;
720 unsigned int sects_per_block;
721 __u64 *sn;
722 int ret = 0;
723
724 sects_per_block = (1 << nilfs->ns_blocksize_bits) /
725 bdev_logical_block_size(nilfs->ns_bdev);
726 for (sn = segnump; sn < segnump + nsegs; sn++) {
727 nilfs_get_segment_range(nilfs, *sn, &seg_start, &seg_end);
728
729 if (!nblocks) {
730 start = seg_start;
731 nblocks = seg_end - seg_start + 1;
732 } else if (start + nblocks == seg_start) {
733 nblocks += seg_end - seg_start + 1;
734 } else {
735 ret = blkdev_issue_discard(nilfs->ns_bdev,
736 start * sects_per_block,
737 nblocks * sects_per_block,
738 GFP_NOFS);
739 if (ret < 0)
740 return ret;
741 nblocks = 0;
742 }
743 }
744 if (nblocks)
745 ret = blkdev_issue_discard(nilfs->ns_bdev,
746 start * sects_per_block,
747 nblocks * sects_per_block,
748 GFP_NOFS);
749 return ret;
750}
751
752int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks)
753{
754 unsigned long ncleansegs;
755
756 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
757 *nblocks = (sector_t)ncleansegs * nilfs->ns_blocks_per_segment;
758 return 0;
759}
760
761int nilfs_near_disk_full(struct the_nilfs *nilfs)
762{
763 unsigned long ncleansegs, nincsegs;
764
765 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
766 nincsegs = atomic_read(&nilfs->ns_ndirtyblks) /
767 nilfs->ns_blocks_per_segment + 1;
768
769 return ncleansegs <= nilfs->ns_nrsvsegs + nincsegs;
770}
771
772struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno)
773{
774 struct rb_node *n;
775 struct nilfs_root *root;
776
777 spin_lock(&nilfs->ns_cptree_lock);
778 n = nilfs->ns_cptree.rb_node;
779 while (n) {
780 root = rb_entry(n, struct nilfs_root, rb_node);
781
782 if (cno < root->cno) {
783 n = n->rb_left;
784 } else if (cno > root->cno) {
785 n = n->rb_right;
786 } else {
787 refcount_inc(&root->count);
788 spin_unlock(&nilfs->ns_cptree_lock);
789 return root;
790 }
791 }
792 spin_unlock(&nilfs->ns_cptree_lock);
793
794 return NULL;
795}
796
797struct nilfs_root *
798nilfs_find_or_create_root(struct the_nilfs *nilfs, __u64 cno)
799{
800 struct rb_node **p, *parent;
801 struct nilfs_root *root, *new;
802 int err;
803
804 root = nilfs_lookup_root(nilfs, cno);
805 if (root)
806 return root;
807
808 new = kzalloc(sizeof(*root), GFP_KERNEL);
809 if (!new)
810 return NULL;
811
812 spin_lock(&nilfs->ns_cptree_lock);
813
814 p = &nilfs->ns_cptree.rb_node;
815 parent = NULL;
816
817 while (*p) {
818 parent = *p;
819 root = rb_entry(parent, struct nilfs_root, rb_node);
820
821 if (cno < root->cno) {
822 p = &(*p)->rb_left;
823 } else if (cno > root->cno) {
824 p = &(*p)->rb_right;
825 } else {
826 refcount_inc(&root->count);
827 spin_unlock(&nilfs->ns_cptree_lock);
828 kfree(new);
829 return root;
830 }
831 }
832
833 new->cno = cno;
834 new->ifile = NULL;
835 new->nilfs = nilfs;
836 refcount_set(&new->count, 1);
837 atomic64_set(&new->inodes_count, 0);
838 atomic64_set(&new->blocks_count, 0);
839
840 rb_link_node(&new->rb_node, parent, p);
841 rb_insert_color(&new->rb_node, &nilfs->ns_cptree);
842
843 spin_unlock(&nilfs->ns_cptree_lock);
844
845 err = nilfs_sysfs_create_snapshot_group(new);
846 if (err) {
847 kfree(new);
848 new = NULL;
849 }
850
851 return new;
852}
853
854void nilfs_put_root(struct nilfs_root *root)
855{
856 struct the_nilfs *nilfs = root->nilfs;
857
858 if (refcount_dec_and_lock(&root->count, &nilfs->ns_cptree_lock)) {
859 rb_erase(&root->rb_node, &nilfs->ns_cptree);
860 spin_unlock(&nilfs->ns_cptree_lock);
861
862 nilfs_sysfs_delete_snapshot_group(root);
863 iput(root->ifile);
864
865 kfree(root);
866 }
867}