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/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
27 static int nilfs_valid_sb(struct nilfs_super_block *sbp);
28
nilfs_set_last_segment(struct the_nilfs * nilfs,sector_t start_blocknr,u64 seq,__u64 cno)29 void 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 */
alloc_nilfs(struct super_block * sb)56 struct 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 */
destroy_nilfs(struct the_nilfs * nilfs)86 void destroy_nilfs(struct the_nilfs *nilfs)
87 {
88 might_sleep();
89 if (nilfs_init(nilfs)) {
90 brelse(nilfs->ns_sbh[0]);
91 brelse(nilfs->ns_sbh[1]);
92 }
93 kfree(nilfs);
94 }
95
nilfs_load_super_root(struct the_nilfs * nilfs,struct super_block * sb,sector_t sr_block)96 static 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
nilfs_init_recovery_info(struct nilfs_recovery_info * ri)150 static 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
nilfs_clear_recovery_info(struct nilfs_recovery_info * ri)156 static 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 */
nilfs_store_log_cursor(struct the_nilfs * nilfs,struct nilfs_super_block * sbp)171 static 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 */
load_nilfs(struct the_nilfs * nilfs,struct super_block * sb)204 int 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 err = nilfs_sysfs_create_device_group(sb);
278 if (unlikely(err))
279 goto sysfs_error;
280
281 if (valid_fs)
282 goto skip_recovery;
283
284 if (s_flags & SB_RDONLY) {
285 __u64 features;
286
287 if (nilfs_test_opt(nilfs, NORECOVERY)) {
288 nilfs_msg(sb, KERN_INFO,
289 "norecovery option specified, skipping roll-forward recovery");
290 goto skip_recovery;
291 }
292 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
293 ~NILFS_FEATURE_COMPAT_RO_SUPP;
294 if (features) {
295 nilfs_msg(sb, KERN_ERR,
296 "couldn't proceed with recovery because of unsupported optional features (%llx)",
297 (unsigned long long)features);
298 err = -EROFS;
299 goto failed_unload;
300 }
301 if (really_read_only) {
302 nilfs_msg(sb, KERN_ERR,
303 "write access unavailable, cannot proceed");
304 err = -EROFS;
305 goto failed_unload;
306 }
307 sb->s_flags &= ~SB_RDONLY;
308 } else if (nilfs_test_opt(nilfs, NORECOVERY)) {
309 nilfs_msg(sb, KERN_ERR,
310 "recovery cancelled because norecovery option was specified for a read/write mount");
311 err = -EINVAL;
312 goto failed_unload;
313 }
314
315 err = nilfs_salvage_orphan_logs(nilfs, sb, &ri);
316 if (err)
317 goto failed_unload;
318
319 down_write(&nilfs->ns_sem);
320 nilfs->ns_mount_state |= NILFS_VALID_FS; /* set "clean" flag */
321 err = nilfs_cleanup_super(sb);
322 up_write(&nilfs->ns_sem);
323
324 if (err) {
325 nilfs_msg(sb, KERN_ERR,
326 "error %d updating super block. recovery unfinished.",
327 err);
328 goto failed_unload;
329 }
330 nilfs_msg(sb, KERN_INFO, "recovery complete");
331
332 skip_recovery:
333 nilfs_clear_recovery_info(&ri);
334 sb->s_flags = s_flags;
335 return 0;
336
337 scan_error:
338 nilfs_msg(sb, KERN_ERR, "error %d while searching super root", err);
339 goto failed;
340
341 failed_unload:
342 nilfs_sysfs_delete_device_group(nilfs);
343
344 sysfs_error:
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
nilfs_max_size(unsigned int blkbits)355 static 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 */
nilfs_nrsvsegs(struct the_nilfs * nilfs,unsigned long nsegs)371 unsigned 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
378 /**
379 * nilfs_max_segment_count - calculate the maximum number of segments
380 * @nilfs: nilfs object
381 */
nilfs_max_segment_count(struct the_nilfs * nilfs)382 static u64 nilfs_max_segment_count(struct the_nilfs *nilfs)
383 {
384 u64 max_count = U64_MAX;
385
386 do_div(max_count, nilfs->ns_blocks_per_segment);
387 return min_t(u64, max_count, ULONG_MAX);
388 }
389
nilfs_set_nsegments(struct the_nilfs * nilfs,unsigned long nsegs)390 void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs)
391 {
392 nilfs->ns_nsegments = nsegs;
393 nilfs->ns_nrsvsegs = nilfs_nrsvsegs(nilfs, nsegs);
394 }
395
nilfs_store_disk_layout(struct the_nilfs * nilfs,struct nilfs_super_block * sbp)396 static int nilfs_store_disk_layout(struct the_nilfs *nilfs,
397 struct nilfs_super_block *sbp)
398 {
399 u64 nsegments, nblocks;
400
401 if (le32_to_cpu(sbp->s_rev_level) < NILFS_MIN_SUPP_REV) {
402 nilfs_msg(nilfs->ns_sb, KERN_ERR,
403 "unsupported revision (superblock rev.=%d.%d, current rev.=%d.%d). Please check the version of mkfs.nilfs(2).",
404 le32_to_cpu(sbp->s_rev_level),
405 le16_to_cpu(sbp->s_minor_rev_level),
406 NILFS_CURRENT_REV, NILFS_MINOR_REV);
407 return -EINVAL;
408 }
409 nilfs->ns_sbsize = le16_to_cpu(sbp->s_bytes);
410 if (nilfs->ns_sbsize > BLOCK_SIZE)
411 return -EINVAL;
412
413 nilfs->ns_inode_size = le16_to_cpu(sbp->s_inode_size);
414 if (nilfs->ns_inode_size > nilfs->ns_blocksize) {
415 nilfs_msg(nilfs->ns_sb, KERN_ERR,
416 "too large inode size: %d bytes",
417 nilfs->ns_inode_size);
418 return -EINVAL;
419 } else if (nilfs->ns_inode_size < NILFS_MIN_INODE_SIZE) {
420 nilfs_msg(nilfs->ns_sb, KERN_ERR,
421 "too small inode size: %d bytes",
422 nilfs->ns_inode_size);
423 return -EINVAL;
424 }
425
426 nilfs->ns_first_ino = le32_to_cpu(sbp->s_first_ino);
427
428 nilfs->ns_blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment);
429 if (nilfs->ns_blocks_per_segment < NILFS_SEG_MIN_BLOCKS) {
430 nilfs_msg(nilfs->ns_sb, KERN_ERR,
431 "too short segment: %lu blocks",
432 nilfs->ns_blocks_per_segment);
433 return -EINVAL;
434 }
435
436 nilfs->ns_first_data_block = le64_to_cpu(sbp->s_first_data_block);
437 nilfs->ns_r_segments_percentage =
438 le32_to_cpu(sbp->s_r_segments_percentage);
439 if (nilfs->ns_r_segments_percentage < 1 ||
440 nilfs->ns_r_segments_percentage > 99) {
441 nilfs_msg(nilfs->ns_sb, KERN_ERR,
442 "invalid reserved segments percentage: %lu",
443 nilfs->ns_r_segments_percentage);
444 return -EINVAL;
445 }
446
447 nsegments = le64_to_cpu(sbp->s_nsegments);
448 if (nsegments > nilfs_max_segment_count(nilfs)) {
449 nilfs_msg(nilfs->ns_sb, KERN_ERR,
450 "segment count %llu exceeds upper limit (%llu segments)",
451 (unsigned long long)nsegments,
452 (unsigned long long)nilfs_max_segment_count(nilfs));
453 return -EINVAL;
454 }
455
456 nblocks = (u64)i_size_read(nilfs->ns_sb->s_bdev->bd_inode) >>
457 nilfs->ns_sb->s_blocksize_bits;
458 if (nblocks) {
459 u64 min_block_count = nsegments * nilfs->ns_blocks_per_segment;
460 /*
461 * To avoid failing to mount early device images without a
462 * second superblock, exclude that block count from the
463 * "min_block_count" calculation.
464 */
465
466 if (nblocks < min_block_count) {
467 nilfs_msg(nilfs->ns_sb, KERN_ERR,
468 "total number of segment blocks %llu exceeds device size (%llu blocks)",
469 (unsigned long long)min_block_count,
470 (unsigned long long)nblocks);
471 return -EINVAL;
472 }
473 }
474
475 nilfs_set_nsegments(nilfs, nsegments);
476 nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed);
477 return 0;
478 }
479
nilfs_valid_sb(struct nilfs_super_block * sbp)480 static int nilfs_valid_sb(struct nilfs_super_block *sbp)
481 {
482 static unsigned char sum[4];
483 const int sumoff = offsetof(struct nilfs_super_block, s_sum);
484 size_t bytes;
485 u32 crc;
486
487 if (!sbp || le16_to_cpu(sbp->s_magic) != NILFS_SUPER_MAGIC)
488 return 0;
489 bytes = le16_to_cpu(sbp->s_bytes);
490 if (bytes < sumoff + 4 || bytes > BLOCK_SIZE)
491 return 0;
492 crc = crc32_le(le32_to_cpu(sbp->s_crc_seed), (unsigned char *)sbp,
493 sumoff);
494 crc = crc32_le(crc, sum, 4);
495 crc = crc32_le(crc, (unsigned char *)sbp + sumoff + 4,
496 bytes - sumoff - 4);
497 return crc == le32_to_cpu(sbp->s_sum);
498 }
499
500 /**
501 * nilfs_sb2_bad_offset - check the location of the second superblock
502 * @sbp: superblock raw data buffer
503 * @offset: byte offset of second superblock calculated from device size
504 *
505 * nilfs_sb2_bad_offset() checks if the position on the second
506 * superblock is valid or not based on the filesystem parameters
507 * stored in @sbp. If @offset points to a location within the segment
508 * area, or if the parameters themselves are not normal, it is
509 * determined to be invalid.
510 *
511 * Return Value: true if invalid, false if valid.
512 */
nilfs_sb2_bad_offset(struct nilfs_super_block * sbp,u64 offset)513 static bool nilfs_sb2_bad_offset(struct nilfs_super_block *sbp, u64 offset)
514 {
515 unsigned int shift_bits = le32_to_cpu(sbp->s_log_block_size);
516 u32 blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment);
517 u64 nsegments = le64_to_cpu(sbp->s_nsegments);
518 u64 index;
519
520 if (blocks_per_segment < NILFS_SEG_MIN_BLOCKS ||
521 shift_bits > ilog2(NILFS_MAX_BLOCK_SIZE) - BLOCK_SIZE_BITS)
522 return true;
523
524 index = offset >> (shift_bits + BLOCK_SIZE_BITS);
525 do_div(index, blocks_per_segment);
526 return index < nsegments;
527 }
528
nilfs_release_super_block(struct the_nilfs * nilfs)529 static void nilfs_release_super_block(struct the_nilfs *nilfs)
530 {
531 int i;
532
533 for (i = 0; i < 2; i++) {
534 if (nilfs->ns_sbp[i]) {
535 brelse(nilfs->ns_sbh[i]);
536 nilfs->ns_sbh[i] = NULL;
537 nilfs->ns_sbp[i] = NULL;
538 }
539 }
540 }
541
nilfs_fall_back_super_block(struct the_nilfs * nilfs)542 void nilfs_fall_back_super_block(struct the_nilfs *nilfs)
543 {
544 brelse(nilfs->ns_sbh[0]);
545 nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
546 nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
547 nilfs->ns_sbh[1] = NULL;
548 nilfs->ns_sbp[1] = NULL;
549 }
550
nilfs_swap_super_block(struct the_nilfs * nilfs)551 void nilfs_swap_super_block(struct the_nilfs *nilfs)
552 {
553 struct buffer_head *tsbh = nilfs->ns_sbh[0];
554 struct nilfs_super_block *tsbp = nilfs->ns_sbp[0];
555
556 nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
557 nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
558 nilfs->ns_sbh[1] = tsbh;
559 nilfs->ns_sbp[1] = tsbp;
560 }
561
nilfs_load_super_block(struct the_nilfs * nilfs,struct super_block * sb,int blocksize,struct nilfs_super_block ** sbpp)562 static int nilfs_load_super_block(struct the_nilfs *nilfs,
563 struct super_block *sb, int blocksize,
564 struct nilfs_super_block **sbpp)
565 {
566 struct nilfs_super_block **sbp = nilfs->ns_sbp;
567 struct buffer_head **sbh = nilfs->ns_sbh;
568 u64 sb2off, devsize = nilfs->ns_bdev->bd_inode->i_size;
569 int valid[2], swp = 0;
570
571 if (devsize < NILFS_SEG_MIN_BLOCKS * NILFS_MIN_BLOCK_SIZE + 4096) {
572 nilfs_msg(sb, KERN_ERR, "device size too small");
573 return -EINVAL;
574 }
575 sb2off = NILFS_SB2_OFFSET_BYTES(devsize);
576
577 sbp[0] = nilfs_read_super_block(sb, NILFS_SB_OFFSET_BYTES, blocksize,
578 &sbh[0]);
579 sbp[1] = nilfs_read_super_block(sb, sb2off, blocksize, &sbh[1]);
580
581 if (!sbp[0]) {
582 if (!sbp[1]) {
583 nilfs_msg(sb, KERN_ERR, "unable to read superblock");
584 return -EIO;
585 }
586 nilfs_msg(sb, KERN_WARNING,
587 "unable to read primary superblock (blocksize = %d)",
588 blocksize);
589 } else if (!sbp[1]) {
590 nilfs_msg(sb, KERN_WARNING,
591 "unable to read secondary superblock (blocksize = %d)",
592 blocksize);
593 }
594
595 /*
596 * Compare two super blocks and set 1 in swp if the secondary
597 * super block is valid and newer. Otherwise, set 0 in swp.
598 */
599 valid[0] = nilfs_valid_sb(sbp[0]);
600 valid[1] = nilfs_valid_sb(sbp[1]);
601 swp = valid[1] && (!valid[0] ||
602 le64_to_cpu(sbp[1]->s_last_cno) >
603 le64_to_cpu(sbp[0]->s_last_cno));
604
605 if (valid[swp] && nilfs_sb2_bad_offset(sbp[swp], sb2off)) {
606 brelse(sbh[1]);
607 sbh[1] = NULL;
608 sbp[1] = NULL;
609 valid[1] = 0;
610 swp = 0;
611 }
612 if (!valid[swp]) {
613 nilfs_release_super_block(nilfs);
614 nilfs_msg(sb, KERN_ERR, "couldn't find nilfs on the device");
615 return -EINVAL;
616 }
617
618 if (!valid[!swp])
619 nilfs_msg(sb, KERN_WARNING,
620 "broken superblock, retrying with spare superblock (blocksize = %d)",
621 blocksize);
622 if (swp)
623 nilfs_swap_super_block(nilfs);
624
625 nilfs->ns_sbwcount = 0;
626 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime);
627 nilfs->ns_prot_seq = le64_to_cpu(sbp[valid[1] & !swp]->s_last_seq);
628 *sbpp = sbp[0];
629 return 0;
630 }
631
632 /**
633 * init_nilfs - initialize a NILFS instance.
634 * @nilfs: the_nilfs structure
635 * @sb: super block
636 * @data: mount options
637 *
638 * init_nilfs() performs common initialization per block device (e.g.
639 * reading the super block, getting disk layout information, initializing
640 * shared fields in the_nilfs).
641 *
642 * Return Value: On success, 0 is returned. On error, a negative error
643 * code is returned.
644 */
init_nilfs(struct the_nilfs * nilfs,struct super_block * sb,char * data)645 int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data)
646 {
647 struct nilfs_super_block *sbp;
648 int blocksize;
649 int err;
650
651 down_write(&nilfs->ns_sem);
652
653 blocksize = sb_min_blocksize(sb, NILFS_MIN_BLOCK_SIZE);
654 if (!blocksize) {
655 nilfs_msg(sb, KERN_ERR, "unable to set blocksize");
656 err = -EINVAL;
657 goto out;
658 }
659 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
660 if (err)
661 goto out;
662
663 err = nilfs_store_magic_and_option(sb, sbp, data);
664 if (err)
665 goto failed_sbh;
666
667 err = nilfs_check_feature_compatibility(sb, sbp);
668 if (err)
669 goto failed_sbh;
670
671 blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size);
672 if (blocksize < NILFS_MIN_BLOCK_SIZE ||
673 blocksize > NILFS_MAX_BLOCK_SIZE) {
674 nilfs_msg(sb, KERN_ERR,
675 "couldn't mount because of unsupported filesystem blocksize %d",
676 blocksize);
677 err = -EINVAL;
678 goto failed_sbh;
679 }
680 if (sb->s_blocksize != blocksize) {
681 int hw_blocksize = bdev_logical_block_size(sb->s_bdev);
682
683 if (blocksize < hw_blocksize) {
684 nilfs_msg(sb, KERN_ERR,
685 "blocksize %d too small for device (sector-size = %d)",
686 blocksize, hw_blocksize);
687 err = -EINVAL;
688 goto failed_sbh;
689 }
690 nilfs_release_super_block(nilfs);
691 sb_set_blocksize(sb, blocksize);
692
693 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
694 if (err)
695 goto out;
696 /*
697 * Not to failed_sbh; sbh is released automatically
698 * when reloading fails.
699 */
700 }
701 nilfs->ns_blocksize_bits = sb->s_blocksize_bits;
702 nilfs->ns_blocksize = blocksize;
703
704 get_random_bytes(&nilfs->ns_next_generation,
705 sizeof(nilfs->ns_next_generation));
706
707 err = nilfs_store_disk_layout(nilfs, sbp);
708 if (err)
709 goto failed_sbh;
710
711 sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits);
712
713 nilfs->ns_mount_state = le16_to_cpu(sbp->s_state);
714
715 err = nilfs_store_log_cursor(nilfs, sbp);
716 if (err)
717 goto failed_sbh;
718
719 set_nilfs_init(nilfs);
720 err = 0;
721 out:
722 up_write(&nilfs->ns_sem);
723 return err;
724
725 failed_sbh:
726 nilfs_release_super_block(nilfs);
727 goto out;
728 }
729
nilfs_discard_segments(struct the_nilfs * nilfs,__u64 * segnump,size_t nsegs)730 int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump,
731 size_t nsegs)
732 {
733 sector_t seg_start, seg_end;
734 sector_t start = 0, nblocks = 0;
735 unsigned int sects_per_block;
736 __u64 *sn;
737 int ret = 0;
738
739 sects_per_block = (1 << nilfs->ns_blocksize_bits) /
740 bdev_logical_block_size(nilfs->ns_bdev);
741 for (sn = segnump; sn < segnump + nsegs; sn++) {
742 nilfs_get_segment_range(nilfs, *sn, &seg_start, &seg_end);
743
744 if (!nblocks) {
745 start = seg_start;
746 nblocks = seg_end - seg_start + 1;
747 } else if (start + nblocks == seg_start) {
748 nblocks += seg_end - seg_start + 1;
749 } else {
750 ret = blkdev_issue_discard(nilfs->ns_bdev,
751 start * sects_per_block,
752 nblocks * sects_per_block,
753 GFP_NOFS, 0);
754 if (ret < 0)
755 return ret;
756 nblocks = 0;
757 }
758 }
759 if (nblocks)
760 ret = blkdev_issue_discard(nilfs->ns_bdev,
761 start * sects_per_block,
762 nblocks * sects_per_block,
763 GFP_NOFS, 0);
764 return ret;
765 }
766
nilfs_count_free_blocks(struct the_nilfs * nilfs,sector_t * nblocks)767 int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks)
768 {
769 unsigned long ncleansegs;
770
771 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
772 *nblocks = (sector_t)ncleansegs * nilfs->ns_blocks_per_segment;
773 return 0;
774 }
775
nilfs_near_disk_full(struct the_nilfs * nilfs)776 int nilfs_near_disk_full(struct the_nilfs *nilfs)
777 {
778 unsigned long ncleansegs, nincsegs;
779
780 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
781 nincsegs = atomic_read(&nilfs->ns_ndirtyblks) /
782 nilfs->ns_blocks_per_segment + 1;
783
784 return ncleansegs <= nilfs->ns_nrsvsegs + nincsegs;
785 }
786
nilfs_lookup_root(struct the_nilfs * nilfs,__u64 cno)787 struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno)
788 {
789 struct rb_node *n;
790 struct nilfs_root *root;
791
792 spin_lock(&nilfs->ns_cptree_lock);
793 n = nilfs->ns_cptree.rb_node;
794 while (n) {
795 root = rb_entry(n, struct nilfs_root, rb_node);
796
797 if (cno < root->cno) {
798 n = n->rb_left;
799 } else if (cno > root->cno) {
800 n = n->rb_right;
801 } else {
802 refcount_inc(&root->count);
803 spin_unlock(&nilfs->ns_cptree_lock);
804 return root;
805 }
806 }
807 spin_unlock(&nilfs->ns_cptree_lock);
808
809 return NULL;
810 }
811
812 struct nilfs_root *
nilfs_find_or_create_root(struct the_nilfs * nilfs,__u64 cno)813 nilfs_find_or_create_root(struct the_nilfs *nilfs, __u64 cno)
814 {
815 struct rb_node **p, *parent;
816 struct nilfs_root *root, *new;
817 int err;
818
819 root = nilfs_lookup_root(nilfs, cno);
820 if (root)
821 return root;
822
823 new = kzalloc(sizeof(*root), GFP_KERNEL);
824 if (!new)
825 return NULL;
826
827 spin_lock(&nilfs->ns_cptree_lock);
828
829 p = &nilfs->ns_cptree.rb_node;
830 parent = NULL;
831
832 while (*p) {
833 parent = *p;
834 root = rb_entry(parent, struct nilfs_root, rb_node);
835
836 if (cno < root->cno) {
837 p = &(*p)->rb_left;
838 } else if (cno > root->cno) {
839 p = &(*p)->rb_right;
840 } else {
841 refcount_inc(&root->count);
842 spin_unlock(&nilfs->ns_cptree_lock);
843 kfree(new);
844 return root;
845 }
846 }
847
848 new->cno = cno;
849 new->ifile = NULL;
850 new->nilfs = nilfs;
851 refcount_set(&new->count, 1);
852 atomic64_set(&new->inodes_count, 0);
853 atomic64_set(&new->blocks_count, 0);
854
855 rb_link_node(&new->rb_node, parent, p);
856 rb_insert_color(&new->rb_node, &nilfs->ns_cptree);
857
858 spin_unlock(&nilfs->ns_cptree_lock);
859
860 err = nilfs_sysfs_create_snapshot_group(new);
861 if (err) {
862 kfree(new);
863 new = NULL;
864 }
865
866 return new;
867 }
868
nilfs_put_root(struct nilfs_root * root)869 void nilfs_put_root(struct nilfs_root *root)
870 {
871 struct the_nilfs *nilfs = root->nilfs;
872
873 if (refcount_dec_and_lock(&root->count, &nilfs->ns_cptree_lock)) {
874 rb_erase(&root->rb_node, &nilfs->ns_cptree);
875 spin_unlock(&nilfs->ns_cptree_lock);
876
877 nilfs_sysfs_delete_snapshot_group(root);
878 iput(root->ifile);
879
880 kfree(root);
881 }
882 }
883