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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * the_nilfs.c - 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/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 * alloc_nilfs - allocate a nilfs object
50 * @sb: super block instance
51 *
52 * Return Value: On success, pointer to the_nilfs is returned.
53 * On error, NULL is returned.
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 * destroy_nilfs - destroy nilfs object
83 * @nilfs: nilfs object to be released
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 * nilfs_store_log_cursor - load log cursor from a super block
163 * @nilfs: nilfs object
164 * @sbp: buffer storing super block to be read
165 *
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.
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 * 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
199 *
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.
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 * restore super block with its spare and reconfigure
242 * relevant states of the nilfs object.
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 /* 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);
254 goto scan_error;
255 }
256
257 err = nilfs_store_log_cursor(nilfs, sbp[0]);
258 if (err)
259 goto scan_error;
260
261 /* drop clean flag to allow roll-forward and recovery */
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; /* set "clean" flag */
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; /* page cache limit */
352
353 max_bits = blkbits + NILFS_BMAP_KEY_BIT; /* bmap size limit */
354 if (max_bits < 64)
355 res = min_t(unsigned long long, res, (1ULL << max_bits) - 1);
356 return res;
357}
358
359/**
360 * nilfs_nrsvsegs - calculate the number of reserved segments
361 * @nilfs: nilfs object
362 * @nsegs: total number of segments
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 * Compare two super blocks and set 1 in swp if the secondary
520 * super block is valid and newer. Otherwise, set 0 in swp.
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 * init_nilfs - initialize a NILFS instance.
557 * @nilfs: the_nilfs structure
558 * @sb: super block
559 * @data: mount options
560 *
561 * init_nilfs() performs common initialization per block device (e.g.
562 * reading the super block, getting disk layout information, initializing
563 * shared fields in the_nilfs).
564 *
565 * Return Value: On success, 0 is returned. On error, a negative error
566 * code is returned.
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 * Not to failed_sbh; sbh is released automatically
621 * when reloading fails.
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}
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}