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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/*
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 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 *
20 * Written by Ryusuke Konishi <ryusuke@osrg.net>
21 *
22 */
23
24#include <linux/buffer_head.h>
25#include <linux/slab.h>
26#include <linux/blkdev.h>
27#include <linux/backing-dev.h>
28#include <linux/random.h>
29#include <linux/crc32.h>
30#include "nilfs.h"
31#include "segment.h"
32#include "alloc.h"
33#include "cpfile.h"
34#include "sufile.h"
35#include "dat.h"
36#include "segbuf.h"
37
38
39static int nilfs_valid_sb(struct nilfs_super_block *sbp);
40
41void nilfs_set_last_segment(struct the_nilfs *nilfs,
42 sector_t start_blocknr, u64 seq, __u64 cno)
43{
44 spin_lock(&nilfs->ns_last_segment_lock);
45 nilfs->ns_last_pseg = start_blocknr;
46 nilfs->ns_last_seq = seq;
47 nilfs->ns_last_cno = cno;
48
49 if (!nilfs_sb_dirty(nilfs)) {
50 if (nilfs->ns_prev_seq == nilfs->ns_last_seq)
51 goto stay_cursor;
52
53 set_nilfs_sb_dirty(nilfs);
54 }
55 nilfs->ns_prev_seq = nilfs->ns_last_seq;
56
57 stay_cursor:
58 spin_unlock(&nilfs->ns_last_segment_lock);
59}
60
61/**
62 * alloc_nilfs - allocate a nilfs object
63 * @bdev: block device to which the_nilfs is related
64 *
65 * Return Value: On success, pointer to the_nilfs is returned.
66 * On error, NULL is returned.
67 */
68struct the_nilfs *alloc_nilfs(struct block_device *bdev)
69{
70 struct the_nilfs *nilfs;
71
72 nilfs = kzalloc(sizeof(*nilfs), GFP_KERNEL);
73 if (!nilfs)
74 return NULL;
75
76 nilfs->ns_bdev = bdev;
77 atomic_set(&nilfs->ns_ndirtyblks, 0);
78 init_rwsem(&nilfs->ns_sem);
79 mutex_init(&nilfs->ns_snapshot_mount_mutex);
80 INIT_LIST_HEAD(&nilfs->ns_dirty_files);
81 INIT_LIST_HEAD(&nilfs->ns_gc_inodes);
82 spin_lock_init(&nilfs->ns_inode_lock);
83 spin_lock_init(&nilfs->ns_next_gen_lock);
84 spin_lock_init(&nilfs->ns_last_segment_lock);
85 nilfs->ns_cptree = RB_ROOT;
86 spin_lock_init(&nilfs->ns_cptree_lock);
87 init_rwsem(&nilfs->ns_segctor_sem);
88
89 return nilfs;
90}
91
92/**
93 * destroy_nilfs - destroy nilfs object
94 * @nilfs: nilfs object to be released
95 */
96void destroy_nilfs(struct the_nilfs *nilfs)
97{
98 might_sleep();
99 if (nilfs_init(nilfs)) {
100 brelse(nilfs->ns_sbh[0]);
101 brelse(nilfs->ns_sbh[1]);
102 }
103 kfree(nilfs);
104}
105
106static int nilfs_load_super_root(struct the_nilfs *nilfs,
107 struct super_block *sb, sector_t sr_block)
108{
109 struct buffer_head *bh_sr;
110 struct nilfs_super_root *raw_sr;
111 struct nilfs_super_block **sbp = nilfs->ns_sbp;
112 struct nilfs_inode *rawi;
113 unsigned dat_entry_size, segment_usage_size, checkpoint_size;
114 unsigned inode_size;
115 int err;
116
117 err = nilfs_read_super_root_block(nilfs, sr_block, &bh_sr, 1);
118 if (unlikely(err))
119 return err;
120
121 down_read(&nilfs->ns_sem);
122 dat_entry_size = le16_to_cpu(sbp[0]->s_dat_entry_size);
123 checkpoint_size = le16_to_cpu(sbp[0]->s_checkpoint_size);
124 segment_usage_size = le16_to_cpu(sbp[0]->s_segment_usage_size);
125 up_read(&nilfs->ns_sem);
126
127 inode_size = nilfs->ns_inode_size;
128
129 rawi = (void *)bh_sr->b_data + NILFS_SR_DAT_OFFSET(inode_size);
130 err = nilfs_dat_read(sb, dat_entry_size, rawi, &nilfs->ns_dat);
131 if (err)
132 goto failed;
133
134 rawi = (void *)bh_sr->b_data + NILFS_SR_CPFILE_OFFSET(inode_size);
135 err = nilfs_cpfile_read(sb, checkpoint_size, rawi, &nilfs->ns_cpfile);
136 if (err)
137 goto failed_dat;
138
139 rawi = (void *)bh_sr->b_data + NILFS_SR_SUFILE_OFFSET(inode_size);
140 err = nilfs_sufile_read(sb, segment_usage_size, rawi,
141 &nilfs->ns_sufile);
142 if (err)
143 goto failed_cpfile;
144
145 raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
146 nilfs->ns_nongc_ctime = le64_to_cpu(raw_sr->sr_nongc_ctime);
147
148 failed:
149 brelse(bh_sr);
150 return err;
151
152 failed_cpfile:
153 iput(nilfs->ns_cpfile);
154
155 failed_dat:
156 iput(nilfs->ns_dat);
157 goto failed;
158}
159
160static void nilfs_init_recovery_info(struct nilfs_recovery_info *ri)
161{
162 memset(ri, 0, sizeof(*ri));
163 INIT_LIST_HEAD(&ri->ri_used_segments);
164}
165
166static void nilfs_clear_recovery_info(struct nilfs_recovery_info *ri)
167{
168 nilfs_dispose_segment_list(&ri->ri_used_segments);
169}
170
171/**
172 * nilfs_store_log_cursor - load log cursor from a super block
173 * @nilfs: nilfs object
174 * @sbp: buffer storing super block to be read
175 *
176 * nilfs_store_log_cursor() reads the last position of the log
177 * containing a super root from a given super block, and initializes
178 * relevant information on the nilfs object preparatory for log
179 * scanning and recovery.
180 */
181static int nilfs_store_log_cursor(struct the_nilfs *nilfs,
182 struct nilfs_super_block *sbp)
183{
184 int ret = 0;
185
186 nilfs->ns_last_pseg = le64_to_cpu(sbp->s_last_pseg);
187 nilfs->ns_last_cno = le64_to_cpu(sbp->s_last_cno);
188 nilfs->ns_last_seq = le64_to_cpu(sbp->s_last_seq);
189
190 nilfs->ns_prev_seq = nilfs->ns_last_seq;
191 nilfs->ns_seg_seq = nilfs->ns_last_seq;
192 nilfs->ns_segnum =
193 nilfs_get_segnum_of_block(nilfs, nilfs->ns_last_pseg);
194 nilfs->ns_cno = nilfs->ns_last_cno + 1;
195 if (nilfs->ns_segnum >= nilfs->ns_nsegments) {
196 printk(KERN_ERR "NILFS invalid last segment number.\n");
197 ret = -EINVAL;
198 }
199 return ret;
200}
201
202/**
203 * load_nilfs - load and recover the nilfs
204 * @nilfs: the_nilfs structure to be released
205 * @sb: super block isntance used to recover past segment
206 *
207 * load_nilfs() searches and load the latest super root,
208 * attaches the last segment, and does recovery if needed.
209 * The caller must call this exclusively for simultaneous mounts.
210 */
211int load_nilfs(struct the_nilfs *nilfs, struct super_block *sb)
212{
213 struct nilfs_recovery_info ri;
214 unsigned int s_flags = sb->s_flags;
215 int really_read_only = bdev_read_only(nilfs->ns_bdev);
216 int valid_fs = nilfs_valid_fs(nilfs);
217 int err;
218
219 if (!valid_fs) {
220 printk(KERN_WARNING "NILFS warning: mounting unchecked fs\n");
221 if (s_flags & MS_RDONLY) {
222 printk(KERN_INFO "NILFS: INFO: recovery "
223 "required for readonly filesystem.\n");
224 printk(KERN_INFO "NILFS: write access will "
225 "be enabled during recovery.\n");
226 }
227 }
228
229 nilfs_init_recovery_info(&ri);
230
231 err = nilfs_search_super_root(nilfs, &ri);
232 if (unlikely(err)) {
233 struct nilfs_super_block **sbp = nilfs->ns_sbp;
234 int blocksize;
235
236 if (err != -EINVAL)
237 goto scan_error;
238
239 if (!nilfs_valid_sb(sbp[1])) {
240 printk(KERN_WARNING
241 "NILFS warning: unable to fall back to spare"
242 "super block\n");
243 goto scan_error;
244 }
245 printk(KERN_INFO
246 "NILFS: try rollback from an earlier position\n");
247
248 /*
249 * restore super block with its spare and reconfigure
250 * relevant states of the nilfs object.
251 */
252 memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
253 nilfs->ns_crc_seed = le32_to_cpu(sbp[0]->s_crc_seed);
254 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime);
255
256 /* verify consistency between two super blocks */
257 blocksize = BLOCK_SIZE << le32_to_cpu(sbp[0]->s_log_block_size);
258 if (blocksize != nilfs->ns_blocksize) {
259 printk(KERN_WARNING
260 "NILFS warning: blocksize differs between "
261 "two super blocks (%d != %d)\n",
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 printk(KERN_ERR "NILFS: error loading super root.\n");
282 goto failed;
283 }
284
285 if (valid_fs)
286 goto skip_recovery;
287
288 if (s_flags & MS_RDONLY) {
289 __u64 features;
290
291 if (nilfs_test_opt(nilfs, NORECOVERY)) {
292 printk(KERN_INFO "NILFS: norecovery option specified. "
293 "skipping roll-forward recovery\n");
294 goto skip_recovery;
295 }
296 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
297 ~NILFS_FEATURE_COMPAT_RO_SUPP;
298 if (features) {
299 printk(KERN_ERR "NILFS: couldn't proceed with "
300 "recovery because of unsupported optional "
301 "features (%llx)\n",
302 (unsigned long long)features);
303 err = -EROFS;
304 goto failed_unload;
305 }
306 if (really_read_only) {
307 printk(KERN_ERR "NILFS: write access "
308 "unavailable, cannot proceed.\n");
309 err = -EROFS;
310 goto failed_unload;
311 }
312 sb->s_flags &= ~MS_RDONLY;
313 } else if (nilfs_test_opt(nilfs, NORECOVERY)) {
314 printk(KERN_ERR "NILFS: recovery cancelled because norecovery "
315 "option was specified for a read/write mount\n");
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 printk(KERN_ERR "NILFS: failed to update super block. "
331 "recovery unfinished.\n");
332 goto failed_unload;
333 }
334 printk(KERN_INFO "NILFS: recovery complete.\n");
335
336 skip_recovery:
337 nilfs_clear_recovery_info(&ri);
338 sb->s_flags = s_flags;
339 return 0;
340
341 scan_error:
342 printk(KERN_ERR "NILFS: error searching super root.\n");
343 goto failed;
344
345 failed_unload:
346 iput(nilfs->ns_cpfile);
347 iput(nilfs->ns_sufile);
348 iput(nilfs->ns_dat);
349
350 failed:
351 nilfs_clear_recovery_info(&ri);
352 sb->s_flags = s_flags;
353 return err;
354}
355
356static unsigned long long nilfs_max_size(unsigned int blkbits)
357{
358 unsigned int max_bits;
359 unsigned long long res = MAX_LFS_FILESIZE; /* page cache limit */
360
361 max_bits = blkbits + NILFS_BMAP_KEY_BIT; /* bmap size limit */
362 if (max_bits < 64)
363 res = min_t(unsigned long long, res, (1ULL << max_bits) - 1);
364 return res;
365}
366
367/**
368 * nilfs_nrsvsegs - calculate the number of reserved segments
369 * @nilfs: nilfs object
370 * @nsegs: total number of segments
371 */
372unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs)
373{
374 return max_t(unsigned long, NILFS_MIN_NRSVSEGS,
375 DIV_ROUND_UP(nsegs * nilfs->ns_r_segments_percentage,
376 100));
377}
378
379void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs)
380{
381 nilfs->ns_nsegments = nsegs;
382 nilfs->ns_nrsvsegs = nilfs_nrsvsegs(nilfs, nsegs);
383}
384
385static int nilfs_store_disk_layout(struct the_nilfs *nilfs,
386 struct nilfs_super_block *sbp)
387{
388 if (le32_to_cpu(sbp->s_rev_level) < NILFS_MIN_SUPP_REV) {
389 printk(KERN_ERR "NILFS: unsupported revision "
390 "(superblock rev.=%d.%d, current rev.=%d.%d). "
391 "Please check the version of mkfs.nilfs.\n",
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 nilfs->ns_first_ino = le32_to_cpu(sbp->s_first_ino);
403
404 nilfs->ns_blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment);
405 if (nilfs->ns_blocks_per_segment < NILFS_SEG_MIN_BLOCKS) {
406 printk(KERN_ERR "NILFS: too short segment.\n");
407 return -EINVAL;
408 }
409
410 nilfs->ns_first_data_block = le64_to_cpu(sbp->s_first_data_block);
411 nilfs->ns_r_segments_percentage =
412 le32_to_cpu(sbp->s_r_segments_percentage);
413 if (nilfs->ns_r_segments_percentage < 1 ||
414 nilfs->ns_r_segments_percentage > 99) {
415 printk(KERN_ERR "NILFS: invalid reserved segments percentage.\n");
416 return -EINVAL;
417 }
418
419 nilfs_set_nsegments(nilfs, le64_to_cpu(sbp->s_nsegments));
420 nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed);
421 return 0;
422}
423
424static int nilfs_valid_sb(struct nilfs_super_block *sbp)
425{
426 static unsigned char sum[4];
427 const int sumoff = offsetof(struct nilfs_super_block, s_sum);
428 size_t bytes;
429 u32 crc;
430
431 if (!sbp || le16_to_cpu(sbp->s_magic) != NILFS_SUPER_MAGIC)
432 return 0;
433 bytes = le16_to_cpu(sbp->s_bytes);
434 if (bytes > BLOCK_SIZE)
435 return 0;
436 crc = crc32_le(le32_to_cpu(sbp->s_crc_seed), (unsigned char *)sbp,
437 sumoff);
438 crc = crc32_le(crc, sum, 4);
439 crc = crc32_le(crc, (unsigned char *)sbp + sumoff + 4,
440 bytes - sumoff - 4);
441 return crc == le32_to_cpu(sbp->s_sum);
442}
443
444static int nilfs_sb2_bad_offset(struct nilfs_super_block *sbp, u64 offset)
445{
446 return offset < ((le64_to_cpu(sbp->s_nsegments) *
447 le32_to_cpu(sbp->s_blocks_per_segment)) <<
448 (le32_to_cpu(sbp->s_log_block_size) + 10));
449}
450
451static void nilfs_release_super_block(struct the_nilfs *nilfs)
452{
453 int i;
454
455 for (i = 0; i < 2; i++) {
456 if (nilfs->ns_sbp[i]) {
457 brelse(nilfs->ns_sbh[i]);
458 nilfs->ns_sbh[i] = NULL;
459 nilfs->ns_sbp[i] = NULL;
460 }
461 }
462}
463
464void nilfs_fall_back_super_block(struct the_nilfs *nilfs)
465{
466 brelse(nilfs->ns_sbh[0]);
467 nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
468 nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
469 nilfs->ns_sbh[1] = NULL;
470 nilfs->ns_sbp[1] = NULL;
471}
472
473void nilfs_swap_super_block(struct the_nilfs *nilfs)
474{
475 struct buffer_head *tsbh = nilfs->ns_sbh[0];
476 struct nilfs_super_block *tsbp = nilfs->ns_sbp[0];
477
478 nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
479 nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
480 nilfs->ns_sbh[1] = tsbh;
481 nilfs->ns_sbp[1] = tsbp;
482}
483
484static int nilfs_load_super_block(struct the_nilfs *nilfs,
485 struct super_block *sb, int blocksize,
486 struct nilfs_super_block **sbpp)
487{
488 struct nilfs_super_block **sbp = nilfs->ns_sbp;
489 struct buffer_head **sbh = nilfs->ns_sbh;
490 u64 sb2off = NILFS_SB2_OFFSET_BYTES(nilfs->ns_bdev->bd_inode->i_size);
491 int valid[2], swp = 0;
492
493 sbp[0] = nilfs_read_super_block(sb, NILFS_SB_OFFSET_BYTES, blocksize,
494 &sbh[0]);
495 sbp[1] = nilfs_read_super_block(sb, sb2off, blocksize, &sbh[1]);
496
497 if (!sbp[0]) {
498 if (!sbp[1]) {
499 printk(KERN_ERR "NILFS: unable to read superblock\n");
500 return -EIO;
501 }
502 printk(KERN_WARNING
503 "NILFS warning: unable to read primary superblock "
504 "(blocksize = %d)\n", blocksize);
505 } else if (!sbp[1]) {
506 printk(KERN_WARNING
507 "NILFS warning: unable to read secondary superblock "
508 "(blocksize = %d)\n", blocksize);
509 }
510
511 /*
512 * Compare two super blocks and set 1 in swp if the secondary
513 * super block is valid and newer. Otherwise, set 0 in swp.
514 */
515 valid[0] = nilfs_valid_sb(sbp[0]);
516 valid[1] = nilfs_valid_sb(sbp[1]);
517 swp = valid[1] && (!valid[0] ||
518 le64_to_cpu(sbp[1]->s_last_cno) >
519 le64_to_cpu(sbp[0]->s_last_cno));
520
521 if (valid[swp] && nilfs_sb2_bad_offset(sbp[swp], sb2off)) {
522 brelse(sbh[1]);
523 sbh[1] = NULL;
524 sbp[1] = NULL;
525 valid[1] = 0;
526 swp = 0;
527 }
528 if (!valid[swp]) {
529 nilfs_release_super_block(nilfs);
530 printk(KERN_ERR "NILFS: Can't find nilfs on dev %s.\n",
531 sb->s_id);
532 return -EINVAL;
533 }
534
535 if (!valid[!swp])
536 printk(KERN_WARNING "NILFS warning: broken superblock. "
537 "using spare superblock (blocksize = %d).\n", blocksize);
538 if (swp)
539 nilfs_swap_super_block(nilfs);
540
541 nilfs->ns_sbwcount = 0;
542 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime);
543 nilfs->ns_prot_seq = le64_to_cpu(sbp[valid[1] & !swp]->s_last_seq);
544 *sbpp = sbp[0];
545 return 0;
546}
547
548/**
549 * init_nilfs - initialize a NILFS instance.
550 * @nilfs: the_nilfs structure
551 * @sb: super block
552 * @data: mount options
553 *
554 * init_nilfs() performs common initialization per block device (e.g.
555 * reading the super block, getting disk layout information, initializing
556 * shared fields in the_nilfs).
557 *
558 * Return Value: On success, 0 is returned. On error, a negative error
559 * code is returned.
560 */
561int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data)
562{
563 struct nilfs_super_block *sbp;
564 int blocksize;
565 int err;
566
567 down_write(&nilfs->ns_sem);
568
569 blocksize = sb_min_blocksize(sb, NILFS_MIN_BLOCK_SIZE);
570 if (!blocksize) {
571 printk(KERN_ERR "NILFS: unable to set blocksize\n");
572 err = -EINVAL;
573 goto out;
574 }
575 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
576 if (err)
577 goto out;
578
579 err = nilfs_store_magic_and_option(sb, sbp, data);
580 if (err)
581 goto failed_sbh;
582
583 err = nilfs_check_feature_compatibility(sb, sbp);
584 if (err)
585 goto failed_sbh;
586
587 blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size);
588 if (blocksize < NILFS_MIN_BLOCK_SIZE ||
589 blocksize > NILFS_MAX_BLOCK_SIZE) {
590 printk(KERN_ERR "NILFS: couldn't mount because of unsupported "
591 "filesystem blocksize %d\n", blocksize);
592 err = -EINVAL;
593 goto failed_sbh;
594 }
595 if (sb->s_blocksize != blocksize) {
596 int hw_blocksize = bdev_logical_block_size(sb->s_bdev);
597
598 if (blocksize < hw_blocksize) {
599 printk(KERN_ERR
600 "NILFS: blocksize %d too small for device "
601 "(sector-size = %d).\n",
602 blocksize, hw_blocksize);
603 err = -EINVAL;
604 goto failed_sbh;
605 }
606 nilfs_release_super_block(nilfs);
607 sb_set_blocksize(sb, blocksize);
608
609 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
610 if (err)
611 goto out;
612 /* not failed_sbh; sbh is released automatically
613 when reloading fails. */
614 }
615 nilfs->ns_blocksize_bits = sb->s_blocksize_bits;
616 nilfs->ns_blocksize = blocksize;
617
618 get_random_bytes(&nilfs->ns_next_generation,
619 sizeof(nilfs->ns_next_generation));
620
621 err = nilfs_store_disk_layout(nilfs, sbp);
622 if (err)
623 goto failed_sbh;
624
625 sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits);
626
627 nilfs->ns_mount_state = le16_to_cpu(sbp->s_state);
628
629 err = nilfs_store_log_cursor(nilfs, sbp);
630 if (err)
631 goto failed_sbh;
632
633 set_nilfs_init(nilfs);
634 err = 0;
635 out:
636 up_write(&nilfs->ns_sem);
637 return err;
638
639 failed_sbh:
640 nilfs_release_super_block(nilfs);
641 goto out;
642}
643
644int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump,
645 size_t nsegs)
646{
647 sector_t seg_start, seg_end;
648 sector_t start = 0, nblocks = 0;
649 unsigned int sects_per_block;
650 __u64 *sn;
651 int ret = 0;
652
653 sects_per_block = (1 << nilfs->ns_blocksize_bits) /
654 bdev_logical_block_size(nilfs->ns_bdev);
655 for (sn = segnump; sn < segnump + nsegs; sn++) {
656 nilfs_get_segment_range(nilfs, *sn, &seg_start, &seg_end);
657
658 if (!nblocks) {
659 start = seg_start;
660 nblocks = seg_end - seg_start + 1;
661 } else if (start + nblocks == seg_start) {
662 nblocks += seg_end - seg_start + 1;
663 } else {
664 ret = blkdev_issue_discard(nilfs->ns_bdev,
665 start * sects_per_block,
666 nblocks * sects_per_block,
667 GFP_NOFS, 0);
668 if (ret < 0)
669 return ret;
670 nblocks = 0;
671 }
672 }
673 if (nblocks)
674 ret = blkdev_issue_discard(nilfs->ns_bdev,
675 start * sects_per_block,
676 nblocks * sects_per_block,
677 GFP_NOFS, 0);
678 return ret;
679}
680
681int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks)
682{
683 unsigned long ncleansegs;
684
685 down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
686 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
687 up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
688 *nblocks = (sector_t)ncleansegs * nilfs->ns_blocks_per_segment;
689 return 0;
690}
691
692int nilfs_near_disk_full(struct the_nilfs *nilfs)
693{
694 unsigned long ncleansegs, nincsegs;
695
696 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
697 nincsegs = atomic_read(&nilfs->ns_ndirtyblks) /
698 nilfs->ns_blocks_per_segment + 1;
699
700 return ncleansegs <= nilfs->ns_nrsvsegs + nincsegs;
701}
702
703struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno)
704{
705 struct rb_node *n;
706 struct nilfs_root *root;
707
708 spin_lock(&nilfs->ns_cptree_lock);
709 n = nilfs->ns_cptree.rb_node;
710 while (n) {
711 root = rb_entry(n, struct nilfs_root, rb_node);
712
713 if (cno < root->cno) {
714 n = n->rb_left;
715 } else if (cno > root->cno) {
716 n = n->rb_right;
717 } else {
718 atomic_inc(&root->count);
719 spin_unlock(&nilfs->ns_cptree_lock);
720 return root;
721 }
722 }
723 spin_unlock(&nilfs->ns_cptree_lock);
724
725 return NULL;
726}
727
728struct nilfs_root *
729nilfs_find_or_create_root(struct the_nilfs *nilfs, __u64 cno)
730{
731 struct rb_node **p, *parent;
732 struct nilfs_root *root, *new;
733
734 root = nilfs_lookup_root(nilfs, cno);
735 if (root)
736 return root;
737
738 new = kmalloc(sizeof(*root), GFP_KERNEL);
739 if (!new)
740 return NULL;
741
742 spin_lock(&nilfs->ns_cptree_lock);
743
744 p = &nilfs->ns_cptree.rb_node;
745 parent = NULL;
746
747 while (*p) {
748 parent = *p;
749 root = rb_entry(parent, struct nilfs_root, rb_node);
750
751 if (cno < root->cno) {
752 p = &(*p)->rb_left;
753 } else if (cno > root->cno) {
754 p = &(*p)->rb_right;
755 } else {
756 atomic_inc(&root->count);
757 spin_unlock(&nilfs->ns_cptree_lock);
758 kfree(new);
759 return root;
760 }
761 }
762
763 new->cno = cno;
764 new->ifile = NULL;
765 new->nilfs = nilfs;
766 atomic_set(&new->count, 1);
767 atomic_set(&new->inodes_count, 0);
768 atomic_set(&new->blocks_count, 0);
769
770 rb_link_node(&new->rb_node, parent, p);
771 rb_insert_color(&new->rb_node, &nilfs->ns_cptree);
772
773 spin_unlock(&nilfs->ns_cptree_lock);
774
775 return new;
776}
777
778void nilfs_put_root(struct nilfs_root *root)
779{
780 if (atomic_dec_and_test(&root->count)) {
781 struct the_nilfs *nilfs = root->nilfs;
782
783 spin_lock(&nilfs->ns_cptree_lock);
784 rb_erase(&root->rb_node, &nilfs->ns_cptree);
785 spin_unlock(&nilfs->ns_cptree_lock);
786 if (root->ifile)
787 iput(root->ifile);
788
789 kfree(root);
790 }
791}