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1/*
2 * the_nilfs.c - the_nilfs shared structure.
3 *
4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * Written by Ryusuke Konishi.
17 *
18 */
19
20#include <linux/buffer_head.h>
21#include <linux/slab.h>
22#include <linux/blkdev.h>
23#include <linux/backing-dev.h>
24#include <linux/random.h>
25#include <linux/crc32.h>
26#include "nilfs.h"
27#include "segment.h"
28#include "alloc.h"
29#include "cpfile.h"
30#include "sufile.h"
31#include "dat.h"
32#include "segbuf.h"
33
34
35static int nilfs_valid_sb(struct nilfs_super_block *sbp);
36
37void nilfs_set_last_segment(struct the_nilfs *nilfs,
38 sector_t start_blocknr, u64 seq, __u64 cno)
39{
40 spin_lock(&nilfs->ns_last_segment_lock);
41 nilfs->ns_last_pseg = start_blocknr;
42 nilfs->ns_last_seq = seq;
43 nilfs->ns_last_cno = cno;
44
45 if (!nilfs_sb_dirty(nilfs)) {
46 if (nilfs->ns_prev_seq == nilfs->ns_last_seq)
47 goto stay_cursor;
48
49 set_nilfs_sb_dirty(nilfs);
50 }
51 nilfs->ns_prev_seq = nilfs->ns_last_seq;
52
53 stay_cursor:
54 spin_unlock(&nilfs->ns_last_segment_lock);
55}
56
57/**
58 * alloc_nilfs - allocate a nilfs object
59 * @sb: super block instance
60 *
61 * Return Value: On success, pointer to the_nilfs is returned.
62 * On error, NULL is returned.
63 */
64struct the_nilfs *alloc_nilfs(struct super_block *sb)
65{
66 struct the_nilfs *nilfs;
67
68 nilfs = kzalloc(sizeof(*nilfs), GFP_KERNEL);
69 if (!nilfs)
70 return NULL;
71
72 nilfs->ns_sb = sb;
73 nilfs->ns_bdev = sb->s_bdev;
74 atomic_set(&nilfs->ns_ndirtyblks, 0);
75 init_rwsem(&nilfs->ns_sem);
76 mutex_init(&nilfs->ns_snapshot_mount_mutex);
77 INIT_LIST_HEAD(&nilfs->ns_dirty_files);
78 INIT_LIST_HEAD(&nilfs->ns_gc_inodes);
79 spin_lock_init(&nilfs->ns_inode_lock);
80 spin_lock_init(&nilfs->ns_next_gen_lock);
81 spin_lock_init(&nilfs->ns_last_segment_lock);
82 nilfs->ns_cptree = RB_ROOT;
83 spin_lock_init(&nilfs->ns_cptree_lock);
84 init_rwsem(&nilfs->ns_segctor_sem);
85 nilfs->ns_sb_update_freq = NILFS_SB_FREQ;
86
87 return nilfs;
88}
89
90/**
91 * destroy_nilfs - destroy nilfs object
92 * @nilfs: nilfs object to be released
93 */
94void destroy_nilfs(struct the_nilfs *nilfs)
95{
96 might_sleep();
97 if (nilfs_init(nilfs)) {
98 nilfs_sysfs_delete_device_group(nilfs);
99 brelse(nilfs->ns_sbh[0]);
100 brelse(nilfs->ns_sbh[1]);
101 }
102 kfree(nilfs);
103}
104
105static int nilfs_load_super_root(struct the_nilfs *nilfs,
106 struct super_block *sb, sector_t sr_block)
107{
108 struct buffer_head *bh_sr;
109 struct nilfs_super_root *raw_sr;
110 struct nilfs_super_block **sbp = nilfs->ns_sbp;
111 struct nilfs_inode *rawi;
112 unsigned int dat_entry_size, segment_usage_size, checkpoint_size;
113 unsigned int inode_size;
114 int err;
115
116 err = nilfs_read_super_root_block(nilfs, sr_block, &bh_sr, 1);
117 if (unlikely(err))
118 return err;
119
120 down_read(&nilfs->ns_sem);
121 dat_entry_size = le16_to_cpu(sbp[0]->s_dat_entry_size);
122 checkpoint_size = le16_to_cpu(sbp[0]->s_checkpoint_size);
123 segment_usage_size = le16_to_cpu(sbp[0]->s_segment_usage_size);
124 up_read(&nilfs->ns_sem);
125
126 inode_size = nilfs->ns_inode_size;
127
128 rawi = (void *)bh_sr->b_data + NILFS_SR_DAT_OFFSET(inode_size);
129 err = nilfs_dat_read(sb, dat_entry_size, rawi, &nilfs->ns_dat);
130 if (err)
131 goto failed;
132
133 rawi = (void *)bh_sr->b_data + NILFS_SR_CPFILE_OFFSET(inode_size);
134 err = nilfs_cpfile_read(sb, checkpoint_size, rawi, &nilfs->ns_cpfile);
135 if (err)
136 goto failed_dat;
137
138 rawi = (void *)bh_sr->b_data + NILFS_SR_SUFILE_OFFSET(inode_size);
139 err = nilfs_sufile_read(sb, segment_usage_size, rawi,
140 &nilfs->ns_sufile);
141 if (err)
142 goto failed_cpfile;
143
144 raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
145 nilfs->ns_nongc_ctime = le64_to_cpu(raw_sr->sr_nongc_ctime);
146
147 failed:
148 brelse(bh_sr);
149 return err;
150
151 failed_cpfile:
152 iput(nilfs->ns_cpfile);
153
154 failed_dat:
155 iput(nilfs->ns_dat);
156 goto failed;
157}
158
159static void nilfs_init_recovery_info(struct nilfs_recovery_info *ri)
160{
161 memset(ri, 0, sizeof(*ri));
162 INIT_LIST_HEAD(&ri->ri_used_segments);
163}
164
165static void nilfs_clear_recovery_info(struct nilfs_recovery_info *ri)
166{
167 nilfs_dispose_segment_list(&ri->ri_used_segments);
168}
169
170/**
171 * nilfs_store_log_cursor - load log cursor from a super block
172 * @nilfs: nilfs object
173 * @sbp: buffer storing super block to be read
174 *
175 * nilfs_store_log_cursor() reads the last position of the log
176 * containing a super root from a given super block, and initializes
177 * relevant information on the nilfs object preparatory for log
178 * scanning and recovery.
179 */
180static int nilfs_store_log_cursor(struct the_nilfs *nilfs,
181 struct nilfs_super_block *sbp)
182{
183 int ret = 0;
184
185 nilfs->ns_last_pseg = le64_to_cpu(sbp->s_last_pseg);
186 nilfs->ns_last_cno = le64_to_cpu(sbp->s_last_cno);
187 nilfs->ns_last_seq = le64_to_cpu(sbp->s_last_seq);
188
189 nilfs->ns_prev_seq = nilfs->ns_last_seq;
190 nilfs->ns_seg_seq = nilfs->ns_last_seq;
191 nilfs->ns_segnum =
192 nilfs_get_segnum_of_block(nilfs, nilfs->ns_last_pseg);
193 nilfs->ns_cno = nilfs->ns_last_cno + 1;
194 if (nilfs->ns_segnum >= nilfs->ns_nsegments) {
195 nilfs_msg(nilfs->ns_sb, KERN_ERR,
196 "pointed segment number is out of range: segnum=%llu, nsegments=%lu",
197 (unsigned long long)nilfs->ns_segnum,
198 nilfs->ns_nsegments);
199 ret = -EINVAL;
200 }
201 return ret;
202}
203
204/**
205 * load_nilfs - load and recover the nilfs
206 * @nilfs: the_nilfs structure to be released
207 * @sb: super block isntance used to recover past segment
208 *
209 * load_nilfs() searches and load the latest super root,
210 * attaches the last segment, and does recovery if needed.
211 * The caller must call this exclusively for simultaneous mounts.
212 */
213int load_nilfs(struct the_nilfs *nilfs, struct super_block *sb)
214{
215 struct nilfs_recovery_info ri;
216 unsigned int s_flags = sb->s_flags;
217 int really_read_only = bdev_read_only(nilfs->ns_bdev);
218 int valid_fs = nilfs_valid_fs(nilfs);
219 int err;
220
221 if (!valid_fs) {
222 nilfs_msg(sb, KERN_WARNING, "mounting unchecked fs");
223 if (s_flags & SB_RDONLY) {
224 nilfs_msg(sb, KERN_INFO,
225 "recovery required for readonly filesystem");
226 nilfs_msg(sb, KERN_INFO,
227 "write access will be enabled during recovery");
228 }
229 }
230
231 nilfs_init_recovery_info(&ri);
232
233 err = nilfs_search_super_root(nilfs, &ri);
234 if (unlikely(err)) {
235 struct nilfs_super_block **sbp = nilfs->ns_sbp;
236 int blocksize;
237
238 if (err != -EINVAL)
239 goto scan_error;
240
241 if (!nilfs_valid_sb(sbp[1])) {
242 nilfs_msg(sb, KERN_WARNING,
243 "unable to fall back to spare super block");
244 goto scan_error;
245 }
246 nilfs_msg(sb, KERN_INFO,
247 "trying rollback from an earlier position");
248
249 /*
250 * restore super block with its spare and reconfigure
251 * relevant states of the nilfs object.
252 */
253 memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
254 nilfs->ns_crc_seed = le32_to_cpu(sbp[0]->s_crc_seed);
255 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime);
256
257 /* verify consistency between two super blocks */
258 blocksize = BLOCK_SIZE << le32_to_cpu(sbp[0]->s_log_block_size);
259 if (blocksize != nilfs->ns_blocksize) {
260 nilfs_msg(sb, KERN_WARNING,
261 "blocksize differs between two super blocks (%d != %d)",
262 blocksize, nilfs->ns_blocksize);
263 goto scan_error;
264 }
265
266 err = nilfs_store_log_cursor(nilfs, sbp[0]);
267 if (err)
268 goto scan_error;
269
270 /* drop clean flag to allow roll-forward and recovery */
271 nilfs->ns_mount_state &= ~NILFS_VALID_FS;
272 valid_fs = 0;
273
274 err = nilfs_search_super_root(nilfs, &ri);
275 if (err)
276 goto scan_error;
277 }
278
279 err = nilfs_load_super_root(nilfs, sb, ri.ri_super_root);
280 if (unlikely(err)) {
281 nilfs_msg(sb, KERN_ERR, "error %d while loading super root",
282 err);
283 goto failed;
284 }
285
286 if (valid_fs)
287 goto skip_recovery;
288
289 if (s_flags & SB_RDONLY) {
290 __u64 features;
291
292 if (nilfs_test_opt(nilfs, NORECOVERY)) {
293 nilfs_msg(sb, KERN_INFO,
294 "norecovery option specified, skipping roll-forward recovery");
295 goto skip_recovery;
296 }
297 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
298 ~NILFS_FEATURE_COMPAT_RO_SUPP;
299 if (features) {
300 nilfs_msg(sb, KERN_ERR,
301 "couldn't proceed with recovery because of unsupported optional features (%llx)",
302 (unsigned long long)features);
303 err = -EROFS;
304 goto failed_unload;
305 }
306 if (really_read_only) {
307 nilfs_msg(sb, KERN_ERR,
308 "write access unavailable, cannot proceed");
309 err = -EROFS;
310 goto failed_unload;
311 }
312 sb->s_flags &= ~SB_RDONLY;
313 } else if (nilfs_test_opt(nilfs, NORECOVERY)) {
314 nilfs_msg(sb, KERN_ERR,
315 "recovery cancelled because norecovery option was specified for a read/write mount");
316 err = -EINVAL;
317 goto failed_unload;
318 }
319
320 err = nilfs_salvage_orphan_logs(nilfs, sb, &ri);
321 if (err)
322 goto failed_unload;
323
324 down_write(&nilfs->ns_sem);
325 nilfs->ns_mount_state |= NILFS_VALID_FS; /* set "clean" flag */
326 err = nilfs_cleanup_super(sb);
327 up_write(&nilfs->ns_sem);
328
329 if (err) {
330 nilfs_msg(sb, KERN_ERR,
331 "error %d updating super block. recovery unfinished.",
332 err);
333 goto failed_unload;
334 }
335 nilfs_msg(sb, KERN_INFO, "recovery complete");
336
337 skip_recovery:
338 nilfs_clear_recovery_info(&ri);
339 sb->s_flags = s_flags;
340 return 0;
341
342 scan_error:
343 nilfs_msg(sb, KERN_ERR, "error %d while searching super root", err);
344 goto failed;
345
346 failed_unload:
347 iput(nilfs->ns_cpfile);
348 iput(nilfs->ns_sufile);
349 iput(nilfs->ns_dat);
350
351 failed:
352 nilfs_clear_recovery_info(&ri);
353 sb->s_flags = s_flags;
354 return err;
355}
356
357static unsigned long long nilfs_max_size(unsigned int blkbits)
358{
359 unsigned int max_bits;
360 unsigned long long res = MAX_LFS_FILESIZE; /* page cache limit */
361
362 max_bits = blkbits + NILFS_BMAP_KEY_BIT; /* bmap size limit */
363 if (max_bits < 64)
364 res = min_t(unsigned long long, res, (1ULL << max_bits) - 1);
365 return res;
366}
367
368/**
369 * nilfs_nrsvsegs - calculate the number of reserved segments
370 * @nilfs: nilfs object
371 * @nsegs: total number of segments
372 */
373unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs)
374{
375 return max_t(unsigned long, NILFS_MIN_NRSVSEGS,
376 DIV_ROUND_UP(nsegs * nilfs->ns_r_segments_percentage,
377 100));
378}
379
380void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs)
381{
382 nilfs->ns_nsegments = nsegs;
383 nilfs->ns_nrsvsegs = nilfs_nrsvsegs(nilfs, nsegs);
384}
385
386static int nilfs_store_disk_layout(struct the_nilfs *nilfs,
387 struct nilfs_super_block *sbp)
388{
389 if (le32_to_cpu(sbp->s_rev_level) < NILFS_MIN_SUPP_REV) {
390 nilfs_msg(nilfs->ns_sb, KERN_ERR,
391 "unsupported revision (superblock rev.=%d.%d, current rev.=%d.%d). Please check the version of mkfs.nilfs(2).",
392 le32_to_cpu(sbp->s_rev_level),
393 le16_to_cpu(sbp->s_minor_rev_level),
394 NILFS_CURRENT_REV, NILFS_MINOR_REV);
395 return -EINVAL;
396 }
397 nilfs->ns_sbsize = le16_to_cpu(sbp->s_bytes);
398 if (nilfs->ns_sbsize > BLOCK_SIZE)
399 return -EINVAL;
400
401 nilfs->ns_inode_size = le16_to_cpu(sbp->s_inode_size);
402 if (nilfs->ns_inode_size > nilfs->ns_blocksize) {
403 nilfs_msg(nilfs->ns_sb, KERN_ERR,
404 "too large inode size: %d bytes",
405 nilfs->ns_inode_size);
406 return -EINVAL;
407 } else if (nilfs->ns_inode_size < NILFS_MIN_INODE_SIZE) {
408 nilfs_msg(nilfs->ns_sb, KERN_ERR,
409 "too small inode size: %d bytes",
410 nilfs->ns_inode_size);
411 return -EINVAL;
412 }
413
414 nilfs->ns_first_ino = le32_to_cpu(sbp->s_first_ino);
415
416 nilfs->ns_blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment);
417 if (nilfs->ns_blocks_per_segment < NILFS_SEG_MIN_BLOCKS) {
418 nilfs_msg(nilfs->ns_sb, KERN_ERR,
419 "too short segment: %lu blocks",
420 nilfs->ns_blocks_per_segment);
421 return -EINVAL;
422 }
423
424 nilfs->ns_first_data_block = le64_to_cpu(sbp->s_first_data_block);
425 nilfs->ns_r_segments_percentage =
426 le32_to_cpu(sbp->s_r_segments_percentage);
427 if (nilfs->ns_r_segments_percentage < 1 ||
428 nilfs->ns_r_segments_percentage > 99) {
429 nilfs_msg(nilfs->ns_sb, KERN_ERR,
430 "invalid reserved segments percentage: %lu",
431 nilfs->ns_r_segments_percentage);
432 return -EINVAL;
433 }
434
435 nilfs_set_nsegments(nilfs, le64_to_cpu(sbp->s_nsegments));
436 nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed);
437 return 0;
438}
439
440static int nilfs_valid_sb(struct nilfs_super_block *sbp)
441{
442 static unsigned char sum[4];
443 const int sumoff = offsetof(struct nilfs_super_block, s_sum);
444 size_t bytes;
445 u32 crc;
446
447 if (!sbp || le16_to_cpu(sbp->s_magic) != NILFS_SUPER_MAGIC)
448 return 0;
449 bytes = le16_to_cpu(sbp->s_bytes);
450 if (bytes < sumoff + 4 || bytes > BLOCK_SIZE)
451 return 0;
452 crc = crc32_le(le32_to_cpu(sbp->s_crc_seed), (unsigned char *)sbp,
453 sumoff);
454 crc = crc32_le(crc, sum, 4);
455 crc = crc32_le(crc, (unsigned char *)sbp + sumoff + 4,
456 bytes - sumoff - 4);
457 return crc == le32_to_cpu(sbp->s_sum);
458}
459
460static int nilfs_sb2_bad_offset(struct nilfs_super_block *sbp, u64 offset)
461{
462 return offset < ((le64_to_cpu(sbp->s_nsegments) *
463 le32_to_cpu(sbp->s_blocks_per_segment)) <<
464 (le32_to_cpu(sbp->s_log_block_size) + 10));
465}
466
467static void nilfs_release_super_block(struct the_nilfs *nilfs)
468{
469 int i;
470
471 for (i = 0; i < 2; i++) {
472 if (nilfs->ns_sbp[i]) {
473 brelse(nilfs->ns_sbh[i]);
474 nilfs->ns_sbh[i] = NULL;
475 nilfs->ns_sbp[i] = NULL;
476 }
477 }
478}
479
480void nilfs_fall_back_super_block(struct the_nilfs *nilfs)
481{
482 brelse(nilfs->ns_sbh[0]);
483 nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
484 nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
485 nilfs->ns_sbh[1] = NULL;
486 nilfs->ns_sbp[1] = NULL;
487}
488
489void nilfs_swap_super_block(struct the_nilfs *nilfs)
490{
491 struct buffer_head *tsbh = nilfs->ns_sbh[0];
492 struct nilfs_super_block *tsbp = nilfs->ns_sbp[0];
493
494 nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
495 nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
496 nilfs->ns_sbh[1] = tsbh;
497 nilfs->ns_sbp[1] = tsbp;
498}
499
500static int nilfs_load_super_block(struct the_nilfs *nilfs,
501 struct super_block *sb, int blocksize,
502 struct nilfs_super_block **sbpp)
503{
504 struct nilfs_super_block **sbp = nilfs->ns_sbp;
505 struct buffer_head **sbh = nilfs->ns_sbh;
506 u64 sb2off = NILFS_SB2_OFFSET_BYTES(nilfs->ns_bdev->bd_inode->i_size);
507 int valid[2], swp = 0;
508
509 sbp[0] = nilfs_read_super_block(sb, NILFS_SB_OFFSET_BYTES, blocksize,
510 &sbh[0]);
511 sbp[1] = nilfs_read_super_block(sb, sb2off, blocksize, &sbh[1]);
512
513 if (!sbp[0]) {
514 if (!sbp[1]) {
515 nilfs_msg(sb, KERN_ERR, "unable to read superblock");
516 return -EIO;
517 }
518 nilfs_msg(sb, KERN_WARNING,
519 "unable to read primary superblock (blocksize = %d)",
520 blocksize);
521 } else if (!sbp[1]) {
522 nilfs_msg(sb, KERN_WARNING,
523 "unable to read secondary superblock (blocksize = %d)",
524 blocksize);
525 }
526
527 /*
528 * Compare two super blocks and set 1 in swp if the secondary
529 * super block is valid and newer. Otherwise, set 0 in swp.
530 */
531 valid[0] = nilfs_valid_sb(sbp[0]);
532 valid[1] = nilfs_valid_sb(sbp[1]);
533 swp = valid[1] && (!valid[0] ||
534 le64_to_cpu(sbp[1]->s_last_cno) >
535 le64_to_cpu(sbp[0]->s_last_cno));
536
537 if (valid[swp] && nilfs_sb2_bad_offset(sbp[swp], sb2off)) {
538 brelse(sbh[1]);
539 sbh[1] = NULL;
540 sbp[1] = NULL;
541 valid[1] = 0;
542 swp = 0;
543 }
544 if (!valid[swp]) {
545 nilfs_release_super_block(nilfs);
546 nilfs_msg(sb, KERN_ERR, "couldn't find nilfs on the device");
547 return -EINVAL;
548 }
549
550 if (!valid[!swp])
551 nilfs_msg(sb, KERN_WARNING,
552 "broken superblock, retrying with spare superblock (blocksize = %d)",
553 blocksize);
554 if (swp)
555 nilfs_swap_super_block(nilfs);
556
557 nilfs->ns_sbwcount = 0;
558 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime);
559 nilfs->ns_prot_seq = le64_to_cpu(sbp[valid[1] & !swp]->s_last_seq);
560 *sbpp = sbp[0];
561 return 0;
562}
563
564/**
565 * init_nilfs - initialize a NILFS instance.
566 * @nilfs: the_nilfs structure
567 * @sb: super block
568 * @data: mount options
569 *
570 * init_nilfs() performs common initialization per block device (e.g.
571 * reading the super block, getting disk layout information, initializing
572 * shared fields in the_nilfs).
573 *
574 * Return Value: On success, 0 is returned. On error, a negative error
575 * code is returned.
576 */
577int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data)
578{
579 struct nilfs_super_block *sbp;
580 int blocksize;
581 int err;
582
583 down_write(&nilfs->ns_sem);
584
585 blocksize = sb_min_blocksize(sb, NILFS_MIN_BLOCK_SIZE);
586 if (!blocksize) {
587 nilfs_msg(sb, KERN_ERR, "unable to set blocksize");
588 err = -EINVAL;
589 goto out;
590 }
591 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
592 if (err)
593 goto out;
594
595 err = nilfs_store_magic_and_option(sb, sbp, data);
596 if (err)
597 goto failed_sbh;
598
599 err = nilfs_check_feature_compatibility(sb, sbp);
600 if (err)
601 goto failed_sbh;
602
603 blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size);
604 if (blocksize < NILFS_MIN_BLOCK_SIZE ||
605 blocksize > NILFS_MAX_BLOCK_SIZE) {
606 nilfs_msg(sb, KERN_ERR,
607 "couldn't mount because of unsupported filesystem blocksize %d",
608 blocksize);
609 err = -EINVAL;
610 goto failed_sbh;
611 }
612 if (sb->s_blocksize != blocksize) {
613 int hw_blocksize = bdev_logical_block_size(sb->s_bdev);
614
615 if (blocksize < hw_blocksize) {
616 nilfs_msg(sb, KERN_ERR,
617 "blocksize %d too small for device (sector-size = %d)",
618 blocksize, hw_blocksize);
619 err = -EINVAL;
620 goto failed_sbh;
621 }
622 nilfs_release_super_block(nilfs);
623 sb_set_blocksize(sb, blocksize);
624
625 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
626 if (err)
627 goto out;
628 /*
629 * Not to failed_sbh; sbh is released automatically
630 * when reloading fails.
631 */
632 }
633 nilfs->ns_blocksize_bits = sb->s_blocksize_bits;
634 nilfs->ns_blocksize = blocksize;
635
636 get_random_bytes(&nilfs->ns_next_generation,
637 sizeof(nilfs->ns_next_generation));
638
639 err = nilfs_store_disk_layout(nilfs, sbp);
640 if (err)
641 goto failed_sbh;
642
643 sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits);
644
645 nilfs->ns_mount_state = le16_to_cpu(sbp->s_state);
646
647 err = nilfs_store_log_cursor(nilfs, sbp);
648 if (err)
649 goto failed_sbh;
650
651 err = nilfs_sysfs_create_device_group(sb);
652 if (err)
653 goto failed_sbh;
654
655 set_nilfs_init(nilfs);
656 err = 0;
657 out:
658 up_write(&nilfs->ns_sem);
659 return err;
660
661 failed_sbh:
662 nilfs_release_super_block(nilfs);
663 goto out;
664}
665
666int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump,
667 size_t nsegs)
668{
669 sector_t seg_start, seg_end;
670 sector_t start = 0, nblocks = 0;
671 unsigned int sects_per_block;
672 __u64 *sn;
673 int ret = 0;
674
675 sects_per_block = (1 << nilfs->ns_blocksize_bits) /
676 bdev_logical_block_size(nilfs->ns_bdev);
677 for (sn = segnump; sn < segnump + nsegs; sn++) {
678 nilfs_get_segment_range(nilfs, *sn, &seg_start, &seg_end);
679
680 if (!nblocks) {
681 start = seg_start;
682 nblocks = seg_end - seg_start + 1;
683 } else if (start + nblocks == seg_start) {
684 nblocks += seg_end - seg_start + 1;
685 } else {
686 ret = blkdev_issue_discard(nilfs->ns_bdev,
687 start * sects_per_block,
688 nblocks * sects_per_block,
689 GFP_NOFS, 0);
690 if (ret < 0)
691 return ret;
692 nblocks = 0;
693 }
694 }
695 if (nblocks)
696 ret = blkdev_issue_discard(nilfs->ns_bdev,
697 start * sects_per_block,
698 nblocks * sects_per_block,
699 GFP_NOFS, 0);
700 return ret;
701}
702
703int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks)
704{
705 unsigned long ncleansegs;
706
707 down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
708 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
709 up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
710 *nblocks = (sector_t)ncleansegs * nilfs->ns_blocks_per_segment;
711 return 0;
712}
713
714int nilfs_near_disk_full(struct the_nilfs *nilfs)
715{
716 unsigned long ncleansegs, nincsegs;
717
718 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
719 nincsegs = atomic_read(&nilfs->ns_ndirtyblks) /
720 nilfs->ns_blocks_per_segment + 1;
721
722 return ncleansegs <= nilfs->ns_nrsvsegs + nincsegs;
723}
724
725struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno)
726{
727 struct rb_node *n;
728 struct nilfs_root *root;
729
730 spin_lock(&nilfs->ns_cptree_lock);
731 n = nilfs->ns_cptree.rb_node;
732 while (n) {
733 root = rb_entry(n, struct nilfs_root, rb_node);
734
735 if (cno < root->cno) {
736 n = n->rb_left;
737 } else if (cno > root->cno) {
738 n = n->rb_right;
739 } else {
740 refcount_inc(&root->count);
741 spin_unlock(&nilfs->ns_cptree_lock);
742 return root;
743 }
744 }
745 spin_unlock(&nilfs->ns_cptree_lock);
746
747 return NULL;
748}
749
750struct nilfs_root *
751nilfs_find_or_create_root(struct the_nilfs *nilfs, __u64 cno)
752{
753 struct rb_node **p, *parent;
754 struct nilfs_root *root, *new;
755 int err;
756
757 root = nilfs_lookup_root(nilfs, cno);
758 if (root)
759 return root;
760
761 new = kzalloc(sizeof(*root), GFP_KERNEL);
762 if (!new)
763 return NULL;
764
765 spin_lock(&nilfs->ns_cptree_lock);
766
767 p = &nilfs->ns_cptree.rb_node;
768 parent = NULL;
769
770 while (*p) {
771 parent = *p;
772 root = rb_entry(parent, struct nilfs_root, rb_node);
773
774 if (cno < root->cno) {
775 p = &(*p)->rb_left;
776 } else if (cno > root->cno) {
777 p = &(*p)->rb_right;
778 } else {
779 refcount_inc(&root->count);
780 spin_unlock(&nilfs->ns_cptree_lock);
781 kfree(new);
782 return root;
783 }
784 }
785
786 new->cno = cno;
787 new->ifile = NULL;
788 new->nilfs = nilfs;
789 refcount_set(&new->count, 1);
790 atomic64_set(&new->inodes_count, 0);
791 atomic64_set(&new->blocks_count, 0);
792
793 rb_link_node(&new->rb_node, parent, p);
794 rb_insert_color(&new->rb_node, &nilfs->ns_cptree);
795
796 spin_unlock(&nilfs->ns_cptree_lock);
797
798 err = nilfs_sysfs_create_snapshot_group(new);
799 if (err) {
800 kfree(new);
801 new = NULL;
802 }
803
804 return new;
805}
806
807void nilfs_put_root(struct nilfs_root *root)
808{
809 if (refcount_dec_and_test(&root->count)) {
810 struct the_nilfs *nilfs = root->nilfs;
811
812 nilfs_sysfs_delete_snapshot_group(root);
813
814 spin_lock(&nilfs->ns_cptree_lock);
815 rb_erase(&root->rb_node, &nilfs->ns_cptree);
816 spin_unlock(&nilfs->ns_cptree_lock);
817 iput(root->ifile);
818
819 kfree(root);
820 }
821}
1/*
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 INIT_LIST_HEAD(&nilfs->ns_dirty_files);
80 INIT_LIST_HEAD(&nilfs->ns_gc_inodes);
81 spin_lock_init(&nilfs->ns_inode_lock);
82 spin_lock_init(&nilfs->ns_next_gen_lock);
83 spin_lock_init(&nilfs->ns_last_segment_lock);
84 nilfs->ns_cptree = RB_ROOT;
85 spin_lock_init(&nilfs->ns_cptree_lock);
86 init_rwsem(&nilfs->ns_segctor_sem);
87
88 return nilfs;
89}
90
91/**
92 * destroy_nilfs - destroy nilfs object
93 * @nilfs: nilfs object to be released
94 */
95void destroy_nilfs(struct the_nilfs *nilfs)
96{
97 might_sleep();
98 if (nilfs_init(nilfs)) {
99 brelse(nilfs->ns_sbh[0]);
100 brelse(nilfs->ns_sbh[1]);
101 }
102 kfree(nilfs);
103}
104
105static int nilfs_load_super_root(struct the_nilfs *nilfs,
106 struct super_block *sb, sector_t sr_block)
107{
108 struct buffer_head *bh_sr;
109 struct nilfs_super_root *raw_sr;
110 struct nilfs_super_block **sbp = nilfs->ns_sbp;
111 struct nilfs_inode *rawi;
112 unsigned dat_entry_size, segment_usage_size, checkpoint_size;
113 unsigned inode_size;
114 int err;
115
116 err = nilfs_read_super_root_block(nilfs, sr_block, &bh_sr, 1);
117 if (unlikely(err))
118 return err;
119
120 down_read(&nilfs->ns_sem);
121 dat_entry_size = le16_to_cpu(sbp[0]->s_dat_entry_size);
122 checkpoint_size = le16_to_cpu(sbp[0]->s_checkpoint_size);
123 segment_usage_size = le16_to_cpu(sbp[0]->s_segment_usage_size);
124 up_read(&nilfs->ns_sem);
125
126 inode_size = nilfs->ns_inode_size;
127
128 rawi = (void *)bh_sr->b_data + NILFS_SR_DAT_OFFSET(inode_size);
129 err = nilfs_dat_read(sb, dat_entry_size, rawi, &nilfs->ns_dat);
130 if (err)
131 goto failed;
132
133 rawi = (void *)bh_sr->b_data + NILFS_SR_CPFILE_OFFSET(inode_size);
134 err = nilfs_cpfile_read(sb, checkpoint_size, rawi, &nilfs->ns_cpfile);
135 if (err)
136 goto failed_dat;
137
138 rawi = (void *)bh_sr->b_data + NILFS_SR_SUFILE_OFFSET(inode_size);
139 err = nilfs_sufile_read(sb, segment_usage_size, rawi,
140 &nilfs->ns_sufile);
141 if (err)
142 goto failed_cpfile;
143
144 raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
145 nilfs->ns_nongc_ctime = le64_to_cpu(raw_sr->sr_nongc_ctime);
146
147 failed:
148 brelse(bh_sr);
149 return err;
150
151 failed_cpfile:
152 iput(nilfs->ns_cpfile);
153
154 failed_dat:
155 iput(nilfs->ns_dat);
156 goto failed;
157}
158
159static void nilfs_init_recovery_info(struct nilfs_recovery_info *ri)
160{
161 memset(ri, 0, sizeof(*ri));
162 INIT_LIST_HEAD(&ri->ri_used_segments);
163}
164
165static void nilfs_clear_recovery_info(struct nilfs_recovery_info *ri)
166{
167 nilfs_dispose_segment_list(&ri->ri_used_segments);
168}
169
170/**
171 * nilfs_store_log_cursor - load log cursor from a super block
172 * @nilfs: nilfs object
173 * @sbp: buffer storing super block to be read
174 *
175 * nilfs_store_log_cursor() reads the last position of the log
176 * containing a super root from a given super block, and initializes
177 * relevant information on the nilfs object preparatory for log
178 * scanning and recovery.
179 */
180static int nilfs_store_log_cursor(struct the_nilfs *nilfs,
181 struct nilfs_super_block *sbp)
182{
183 int ret = 0;
184
185 nilfs->ns_last_pseg = le64_to_cpu(sbp->s_last_pseg);
186 nilfs->ns_last_cno = le64_to_cpu(sbp->s_last_cno);
187 nilfs->ns_last_seq = le64_to_cpu(sbp->s_last_seq);
188
189 nilfs->ns_prev_seq = nilfs->ns_last_seq;
190 nilfs->ns_seg_seq = nilfs->ns_last_seq;
191 nilfs->ns_segnum =
192 nilfs_get_segnum_of_block(nilfs, nilfs->ns_last_pseg);
193 nilfs->ns_cno = nilfs->ns_last_cno + 1;
194 if (nilfs->ns_segnum >= nilfs->ns_nsegments) {
195 printk(KERN_ERR "NILFS invalid last segment number.\n");
196 ret = -EINVAL;
197 }
198 return ret;
199}
200
201/**
202 * load_nilfs - load and recover the nilfs
203 * @nilfs: the_nilfs structure to be released
204 * @sb: super block isntance used to recover past segment
205 *
206 * load_nilfs() searches and load the latest super root,
207 * attaches the last segment, and does recovery if needed.
208 * The caller must call this exclusively for simultaneous mounts.
209 */
210int load_nilfs(struct the_nilfs *nilfs, struct super_block *sb)
211{
212 struct nilfs_recovery_info ri;
213 unsigned int s_flags = sb->s_flags;
214 int really_read_only = bdev_read_only(nilfs->ns_bdev);
215 int valid_fs = nilfs_valid_fs(nilfs);
216 int err;
217
218 if (!valid_fs) {
219 printk(KERN_WARNING "NILFS warning: mounting unchecked fs\n");
220 if (s_flags & MS_RDONLY) {
221 printk(KERN_INFO "NILFS: INFO: recovery "
222 "required for readonly filesystem.\n");
223 printk(KERN_INFO "NILFS: write access will "
224 "be enabled during recovery.\n");
225 }
226 }
227
228 nilfs_init_recovery_info(&ri);
229
230 err = nilfs_search_super_root(nilfs, &ri);
231 if (unlikely(err)) {
232 struct nilfs_super_block **sbp = nilfs->ns_sbp;
233 int blocksize;
234
235 if (err != -EINVAL)
236 goto scan_error;
237
238 if (!nilfs_valid_sb(sbp[1])) {
239 printk(KERN_WARNING
240 "NILFS warning: unable to fall back to spare"
241 "super block\n");
242 goto scan_error;
243 }
244 printk(KERN_INFO
245 "NILFS: try rollback from an earlier position\n");
246
247 /*
248 * restore super block with its spare and reconfigure
249 * relevant states of the nilfs object.
250 */
251 memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
252 nilfs->ns_crc_seed = le32_to_cpu(sbp[0]->s_crc_seed);
253 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime);
254
255 /* verify consistency between two super blocks */
256 blocksize = BLOCK_SIZE << le32_to_cpu(sbp[0]->s_log_block_size);
257 if (blocksize != nilfs->ns_blocksize) {
258 printk(KERN_WARNING
259 "NILFS warning: blocksize differs between "
260 "two super blocks (%d != %d)\n",
261 blocksize, nilfs->ns_blocksize);
262 goto scan_error;
263 }
264
265 err = nilfs_store_log_cursor(nilfs, sbp[0]);
266 if (err)
267 goto scan_error;
268
269 /* drop clean flag to allow roll-forward and recovery */
270 nilfs->ns_mount_state &= ~NILFS_VALID_FS;
271 valid_fs = 0;
272
273 err = nilfs_search_super_root(nilfs, &ri);
274 if (err)
275 goto scan_error;
276 }
277
278 err = nilfs_load_super_root(nilfs, sb, ri.ri_super_root);
279 if (unlikely(err)) {
280 printk(KERN_ERR "NILFS: error loading super root.\n");
281 goto failed;
282 }
283
284 if (valid_fs)
285 goto skip_recovery;
286
287 if (s_flags & MS_RDONLY) {
288 __u64 features;
289
290 if (nilfs_test_opt(nilfs, NORECOVERY)) {
291 printk(KERN_INFO "NILFS: norecovery option specified. "
292 "skipping roll-forward recovery\n");
293 goto skip_recovery;
294 }
295 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
296 ~NILFS_FEATURE_COMPAT_RO_SUPP;
297 if (features) {
298 printk(KERN_ERR "NILFS: couldn't proceed with "
299 "recovery because of unsupported optional "
300 "features (%llx)\n",
301 (unsigned long long)features);
302 err = -EROFS;
303 goto failed_unload;
304 }
305 if (really_read_only) {
306 printk(KERN_ERR "NILFS: write access "
307 "unavailable, cannot proceed.\n");
308 err = -EROFS;
309 goto failed_unload;
310 }
311 sb->s_flags &= ~MS_RDONLY;
312 } else if (nilfs_test_opt(nilfs, NORECOVERY)) {
313 printk(KERN_ERR "NILFS: recovery cancelled because norecovery "
314 "option was specified for a read/write mount\n");
315 err = -EINVAL;
316 goto failed_unload;
317 }
318
319 err = nilfs_salvage_orphan_logs(nilfs, sb, &ri);
320 if (err)
321 goto failed_unload;
322
323 down_write(&nilfs->ns_sem);
324 nilfs->ns_mount_state |= NILFS_VALID_FS; /* set "clean" flag */
325 err = nilfs_cleanup_super(sb);
326 up_write(&nilfs->ns_sem);
327
328 if (err) {
329 printk(KERN_ERR "NILFS: failed to update super block. "
330 "recovery unfinished.\n");
331 goto failed_unload;
332 }
333 printk(KERN_INFO "NILFS: recovery complete.\n");
334
335 skip_recovery:
336 nilfs_clear_recovery_info(&ri);
337 sb->s_flags = s_flags;
338 return 0;
339
340 scan_error:
341 printk(KERN_ERR "NILFS: error searching super root.\n");
342 goto failed;
343
344 failed_unload:
345 iput(nilfs->ns_cpfile);
346 iput(nilfs->ns_sufile);
347 iput(nilfs->ns_dat);
348
349 failed:
350 nilfs_clear_recovery_info(&ri);
351 sb->s_flags = s_flags;
352 return err;
353}
354
355static unsigned long long nilfs_max_size(unsigned int blkbits)
356{
357 unsigned int max_bits;
358 unsigned long long res = MAX_LFS_FILESIZE; /* page cache limit */
359
360 max_bits = blkbits + NILFS_BMAP_KEY_BIT; /* bmap size limit */
361 if (max_bits < 64)
362 res = min_t(unsigned long long, res, (1ULL << max_bits) - 1);
363 return res;
364}
365
366/**
367 * nilfs_nrsvsegs - calculate the number of reserved segments
368 * @nilfs: nilfs object
369 * @nsegs: total number of segments
370 */
371unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs)
372{
373 return max_t(unsigned long, NILFS_MIN_NRSVSEGS,
374 DIV_ROUND_UP(nsegs * nilfs->ns_r_segments_percentage,
375 100));
376}
377
378void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs)
379{
380 nilfs->ns_nsegments = nsegs;
381 nilfs->ns_nrsvsegs = nilfs_nrsvsegs(nilfs, nsegs);
382}
383
384static int nilfs_store_disk_layout(struct the_nilfs *nilfs,
385 struct nilfs_super_block *sbp)
386{
387 if (le32_to_cpu(sbp->s_rev_level) < NILFS_MIN_SUPP_REV) {
388 printk(KERN_ERR "NILFS: unsupported revision "
389 "(superblock rev.=%d.%d, current rev.=%d.%d). "
390 "Please check the version of mkfs.nilfs.\n",
391 le32_to_cpu(sbp->s_rev_level),
392 le16_to_cpu(sbp->s_minor_rev_level),
393 NILFS_CURRENT_REV, NILFS_MINOR_REV);
394 return -EINVAL;
395 }
396 nilfs->ns_sbsize = le16_to_cpu(sbp->s_bytes);
397 if (nilfs->ns_sbsize > BLOCK_SIZE)
398 return -EINVAL;
399
400 nilfs->ns_inode_size = le16_to_cpu(sbp->s_inode_size);
401 nilfs->ns_first_ino = le32_to_cpu(sbp->s_first_ino);
402
403 nilfs->ns_blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment);
404 if (nilfs->ns_blocks_per_segment < NILFS_SEG_MIN_BLOCKS) {
405 printk(KERN_ERR "NILFS: too short segment.\n");
406 return -EINVAL;
407 }
408
409 nilfs->ns_first_data_block = le64_to_cpu(sbp->s_first_data_block);
410 nilfs->ns_r_segments_percentage =
411 le32_to_cpu(sbp->s_r_segments_percentage);
412 nilfs_set_nsegments(nilfs, le64_to_cpu(sbp->s_nsegments));
413 nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed);
414 return 0;
415}
416
417static int nilfs_valid_sb(struct nilfs_super_block *sbp)
418{
419 static unsigned char sum[4];
420 const int sumoff = offsetof(struct nilfs_super_block, s_sum);
421 size_t bytes;
422 u32 crc;
423
424 if (!sbp || le16_to_cpu(sbp->s_magic) != NILFS_SUPER_MAGIC)
425 return 0;
426 bytes = le16_to_cpu(sbp->s_bytes);
427 if (bytes > BLOCK_SIZE)
428 return 0;
429 crc = crc32_le(le32_to_cpu(sbp->s_crc_seed), (unsigned char *)sbp,
430 sumoff);
431 crc = crc32_le(crc, sum, 4);
432 crc = crc32_le(crc, (unsigned char *)sbp + sumoff + 4,
433 bytes - sumoff - 4);
434 return crc == le32_to_cpu(sbp->s_sum);
435}
436
437static int nilfs_sb2_bad_offset(struct nilfs_super_block *sbp, u64 offset)
438{
439 return offset < ((le64_to_cpu(sbp->s_nsegments) *
440 le32_to_cpu(sbp->s_blocks_per_segment)) <<
441 (le32_to_cpu(sbp->s_log_block_size) + 10));
442}
443
444static void nilfs_release_super_block(struct the_nilfs *nilfs)
445{
446 int i;
447
448 for (i = 0; i < 2; i++) {
449 if (nilfs->ns_sbp[i]) {
450 brelse(nilfs->ns_sbh[i]);
451 nilfs->ns_sbh[i] = NULL;
452 nilfs->ns_sbp[i] = NULL;
453 }
454 }
455}
456
457void nilfs_fall_back_super_block(struct the_nilfs *nilfs)
458{
459 brelse(nilfs->ns_sbh[0]);
460 nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
461 nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
462 nilfs->ns_sbh[1] = NULL;
463 nilfs->ns_sbp[1] = NULL;
464}
465
466void nilfs_swap_super_block(struct the_nilfs *nilfs)
467{
468 struct buffer_head *tsbh = nilfs->ns_sbh[0];
469 struct nilfs_super_block *tsbp = nilfs->ns_sbp[0];
470
471 nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
472 nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
473 nilfs->ns_sbh[1] = tsbh;
474 nilfs->ns_sbp[1] = tsbp;
475}
476
477static int nilfs_load_super_block(struct the_nilfs *nilfs,
478 struct super_block *sb, int blocksize,
479 struct nilfs_super_block **sbpp)
480{
481 struct nilfs_super_block **sbp = nilfs->ns_sbp;
482 struct buffer_head **sbh = nilfs->ns_sbh;
483 u64 sb2off = NILFS_SB2_OFFSET_BYTES(nilfs->ns_bdev->bd_inode->i_size);
484 int valid[2], swp = 0;
485
486 sbp[0] = nilfs_read_super_block(sb, NILFS_SB_OFFSET_BYTES, blocksize,
487 &sbh[0]);
488 sbp[1] = nilfs_read_super_block(sb, sb2off, blocksize, &sbh[1]);
489
490 if (!sbp[0]) {
491 if (!sbp[1]) {
492 printk(KERN_ERR "NILFS: unable to read superblock\n");
493 return -EIO;
494 }
495 printk(KERN_WARNING
496 "NILFS warning: unable to read primary superblock "
497 "(blocksize = %d)\n", blocksize);
498 } else if (!sbp[1]) {
499 printk(KERN_WARNING
500 "NILFS warning: unable to read secondary superblock "
501 "(blocksize = %d)\n", blocksize);
502 }
503
504 /*
505 * Compare two super blocks and set 1 in swp if the secondary
506 * super block is valid and newer. Otherwise, set 0 in swp.
507 */
508 valid[0] = nilfs_valid_sb(sbp[0]);
509 valid[1] = nilfs_valid_sb(sbp[1]);
510 swp = valid[1] && (!valid[0] ||
511 le64_to_cpu(sbp[1]->s_last_cno) >
512 le64_to_cpu(sbp[0]->s_last_cno));
513
514 if (valid[swp] && nilfs_sb2_bad_offset(sbp[swp], sb2off)) {
515 brelse(sbh[1]);
516 sbh[1] = NULL;
517 sbp[1] = NULL;
518 swp = 0;
519 }
520 if (!valid[swp]) {
521 nilfs_release_super_block(nilfs);
522 printk(KERN_ERR "NILFS: Can't find nilfs on dev %s.\n",
523 sb->s_id);
524 return -EINVAL;
525 }
526
527 if (!valid[!swp])
528 printk(KERN_WARNING "NILFS warning: broken superblock. "
529 "using spare superblock (blocksize = %d).\n", blocksize);
530 if (swp)
531 nilfs_swap_super_block(nilfs);
532
533 nilfs->ns_sbwcount = 0;
534 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime);
535 nilfs->ns_prot_seq = le64_to_cpu(sbp[valid[1] & !swp]->s_last_seq);
536 *sbpp = sbp[0];
537 return 0;
538}
539
540/**
541 * init_nilfs - initialize a NILFS instance.
542 * @nilfs: the_nilfs structure
543 * @sb: super block
544 * @data: mount options
545 *
546 * init_nilfs() performs common initialization per block device (e.g.
547 * reading the super block, getting disk layout information, initializing
548 * shared fields in the_nilfs).
549 *
550 * Return Value: On success, 0 is returned. On error, a negative error
551 * code is returned.
552 */
553int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data)
554{
555 struct nilfs_super_block *sbp;
556 int blocksize;
557 int err;
558
559 down_write(&nilfs->ns_sem);
560
561 blocksize = sb_min_blocksize(sb, NILFS_MIN_BLOCK_SIZE);
562 if (!blocksize) {
563 printk(KERN_ERR "NILFS: unable to set blocksize\n");
564 err = -EINVAL;
565 goto out;
566 }
567 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
568 if (err)
569 goto out;
570
571 err = nilfs_store_magic_and_option(sb, sbp, data);
572 if (err)
573 goto failed_sbh;
574
575 err = nilfs_check_feature_compatibility(sb, sbp);
576 if (err)
577 goto failed_sbh;
578
579 blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size);
580 if (blocksize < NILFS_MIN_BLOCK_SIZE ||
581 blocksize > NILFS_MAX_BLOCK_SIZE) {
582 printk(KERN_ERR "NILFS: couldn't mount because of unsupported "
583 "filesystem blocksize %d\n", blocksize);
584 err = -EINVAL;
585 goto failed_sbh;
586 }
587 if (sb->s_blocksize != blocksize) {
588 int hw_blocksize = bdev_logical_block_size(sb->s_bdev);
589
590 if (blocksize < hw_blocksize) {
591 printk(KERN_ERR
592 "NILFS: blocksize %d too small for device "
593 "(sector-size = %d).\n",
594 blocksize, hw_blocksize);
595 err = -EINVAL;
596 goto failed_sbh;
597 }
598 nilfs_release_super_block(nilfs);
599 sb_set_blocksize(sb, blocksize);
600
601 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
602 if (err)
603 goto out;
604 /* not failed_sbh; sbh is released automatically
605 when reloading fails. */
606 }
607 nilfs->ns_blocksize_bits = sb->s_blocksize_bits;
608 nilfs->ns_blocksize = blocksize;
609
610 get_random_bytes(&nilfs->ns_next_generation,
611 sizeof(nilfs->ns_next_generation));
612
613 err = nilfs_store_disk_layout(nilfs, sbp);
614 if (err)
615 goto failed_sbh;
616
617 sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits);
618
619 nilfs->ns_mount_state = le16_to_cpu(sbp->s_state);
620
621 err = nilfs_store_log_cursor(nilfs, sbp);
622 if (err)
623 goto failed_sbh;
624
625 set_nilfs_init(nilfs);
626 err = 0;
627 out:
628 up_write(&nilfs->ns_sem);
629 return err;
630
631 failed_sbh:
632 nilfs_release_super_block(nilfs);
633 goto out;
634}
635
636int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump,
637 size_t nsegs)
638{
639 sector_t seg_start, seg_end;
640 sector_t start = 0, nblocks = 0;
641 unsigned int sects_per_block;
642 __u64 *sn;
643 int ret = 0;
644
645 sects_per_block = (1 << nilfs->ns_blocksize_bits) /
646 bdev_logical_block_size(nilfs->ns_bdev);
647 for (sn = segnump; sn < segnump + nsegs; sn++) {
648 nilfs_get_segment_range(nilfs, *sn, &seg_start, &seg_end);
649
650 if (!nblocks) {
651 start = seg_start;
652 nblocks = seg_end - seg_start + 1;
653 } else if (start + nblocks == seg_start) {
654 nblocks += seg_end - seg_start + 1;
655 } else {
656 ret = blkdev_issue_discard(nilfs->ns_bdev,
657 start * sects_per_block,
658 nblocks * sects_per_block,
659 GFP_NOFS, 0);
660 if (ret < 0)
661 return ret;
662 nblocks = 0;
663 }
664 }
665 if (nblocks)
666 ret = blkdev_issue_discard(nilfs->ns_bdev,
667 start * sects_per_block,
668 nblocks * sects_per_block,
669 GFP_NOFS, 0);
670 return ret;
671}
672
673int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks)
674{
675 unsigned long ncleansegs;
676
677 down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
678 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
679 up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
680 *nblocks = (sector_t)ncleansegs * nilfs->ns_blocks_per_segment;
681 return 0;
682}
683
684int nilfs_near_disk_full(struct the_nilfs *nilfs)
685{
686 unsigned long ncleansegs, nincsegs;
687
688 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
689 nincsegs = atomic_read(&nilfs->ns_ndirtyblks) /
690 nilfs->ns_blocks_per_segment + 1;
691
692 return ncleansegs <= nilfs->ns_nrsvsegs + nincsegs;
693}
694
695struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno)
696{
697 struct rb_node *n;
698 struct nilfs_root *root;
699
700 spin_lock(&nilfs->ns_cptree_lock);
701 n = nilfs->ns_cptree.rb_node;
702 while (n) {
703 root = rb_entry(n, struct nilfs_root, rb_node);
704
705 if (cno < root->cno) {
706 n = n->rb_left;
707 } else if (cno > root->cno) {
708 n = n->rb_right;
709 } else {
710 atomic_inc(&root->count);
711 spin_unlock(&nilfs->ns_cptree_lock);
712 return root;
713 }
714 }
715 spin_unlock(&nilfs->ns_cptree_lock);
716
717 return NULL;
718}
719
720struct nilfs_root *
721nilfs_find_or_create_root(struct the_nilfs *nilfs, __u64 cno)
722{
723 struct rb_node **p, *parent;
724 struct nilfs_root *root, *new;
725
726 root = nilfs_lookup_root(nilfs, cno);
727 if (root)
728 return root;
729
730 new = kmalloc(sizeof(*root), GFP_KERNEL);
731 if (!new)
732 return NULL;
733
734 spin_lock(&nilfs->ns_cptree_lock);
735
736 p = &nilfs->ns_cptree.rb_node;
737 parent = NULL;
738
739 while (*p) {
740 parent = *p;
741 root = rb_entry(parent, struct nilfs_root, rb_node);
742
743 if (cno < root->cno) {
744 p = &(*p)->rb_left;
745 } else if (cno > root->cno) {
746 p = &(*p)->rb_right;
747 } else {
748 atomic_inc(&root->count);
749 spin_unlock(&nilfs->ns_cptree_lock);
750 kfree(new);
751 return root;
752 }
753 }
754
755 new->cno = cno;
756 new->ifile = NULL;
757 new->nilfs = nilfs;
758 atomic_set(&new->count, 1);
759 atomic_set(&new->inodes_count, 0);
760 atomic_set(&new->blocks_count, 0);
761
762 rb_link_node(&new->rb_node, parent, p);
763 rb_insert_color(&new->rb_node, &nilfs->ns_cptree);
764
765 spin_unlock(&nilfs->ns_cptree_lock);
766
767 return new;
768}
769
770void nilfs_put_root(struct nilfs_root *root)
771{
772 if (atomic_dec_and_test(&root->count)) {
773 struct the_nilfs *nilfs = root->nilfs;
774
775 spin_lock(&nilfs->ns_cptree_lock);
776 rb_erase(&root->rb_node, &nilfs->ns_cptree);
777 spin_unlock(&nilfs->ns_cptree_lock);
778 if (root->ifile)
779 iput(root->ifile);
780
781 kfree(root);
782 }
783}