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