1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * super.c - NILFS module and super block management.
4 *
5 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
6 *
7 * Written by Ryusuke Konishi.
8 */
9 /*
10 * linux/fs/ext2/super.c
11 *
12 * Copyright (C) 1992, 1993, 1994, 1995
13 * Remy Card (card@masi.ibp.fr)
14 * Laboratoire MASI - Institut Blaise Pascal
15 * Universite Pierre et Marie Curie (Paris VI)
16 *
17 * from
18 *
19 * linux/fs/minix/inode.c
20 *
21 * Copyright (C) 1991, 1992 Linus Torvalds
22 *
23 * Big-endian to little-endian byte-swapping/bitmaps by
24 * David S. Miller (davem@caip.rutgers.edu), 1995
25 */
26
27 #include <linux/module.h>
28 #include <linux/string.h>
29 #include <linux/slab.h>
30 #include <linux/init.h>
31 #include <linux/blkdev.h>
32 #include <linux/parser.h>
33 #include <linux/crc32.h>
34 #include <linux/vfs.h>
35 #include <linux/writeback.h>
36 #include <linux/seq_file.h>
37 #include <linux/mount.h>
38 #include "nilfs.h"
39 #include "export.h"
40 #include "mdt.h"
41 #include "alloc.h"
42 #include "btree.h"
43 #include "btnode.h"
44 #include "page.h"
45 #include "cpfile.h"
46 #include "sufile.h" /* nilfs_sufile_resize(), nilfs_sufile_set_alloc_range() */
47 #include "ifile.h"
48 #include "dat.h"
49 #include "segment.h"
50 #include "segbuf.h"
51
52 MODULE_AUTHOR("NTT Corp.");
53 MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem "
54 "(NILFS)");
55 MODULE_LICENSE("GPL");
56 MODULE_IMPORT_NS(ANDROID_GKI_VFS_EXPORT_ONLY);
57
58 static struct kmem_cache *nilfs_inode_cachep;
59 struct kmem_cache *nilfs_transaction_cachep;
60 struct kmem_cache *nilfs_segbuf_cachep;
61 struct kmem_cache *nilfs_btree_path_cache;
62
63 static int nilfs_setup_super(struct super_block *sb, int is_mount);
64 static int nilfs_remount(struct super_block *sb, int *flags, char *data);
65
__nilfs_msg(struct super_block * sb,const char * fmt,...)66 void __nilfs_msg(struct super_block *sb, const char *fmt, ...)
67 {
68 struct va_format vaf;
69 va_list args;
70 int level;
71
72 va_start(args, fmt);
73
74 level = printk_get_level(fmt);
75 vaf.fmt = printk_skip_level(fmt);
76 vaf.va = &args;
77
78 if (sb)
79 printk("%c%cNILFS (%s): %pV\n",
80 KERN_SOH_ASCII, level, sb->s_id, &vaf);
81 else
82 printk("%c%cNILFS: %pV\n",
83 KERN_SOH_ASCII, level, &vaf);
84
85 va_end(args);
86 }
87
nilfs_set_error(struct super_block * sb)88 static void nilfs_set_error(struct super_block *sb)
89 {
90 struct the_nilfs *nilfs = sb->s_fs_info;
91 struct nilfs_super_block **sbp;
92
93 down_write(&nilfs->ns_sem);
94 if (!(nilfs->ns_mount_state & NILFS_ERROR_FS)) {
95 nilfs->ns_mount_state |= NILFS_ERROR_FS;
96 sbp = nilfs_prepare_super(sb, 0);
97 if (likely(sbp)) {
98 sbp[0]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
99 if (sbp[1])
100 sbp[1]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
101 nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
102 }
103 }
104 up_write(&nilfs->ns_sem);
105 }
106
107 /**
108 * __nilfs_error() - report failure condition on a filesystem
109 *
110 * __nilfs_error() sets an ERROR_FS flag on the superblock as well as
111 * reporting an error message. This function should be called when
112 * NILFS detects incoherences or defects of meta data on disk.
113 *
114 * This implements the body of nilfs_error() macro. Normally,
115 * nilfs_error() should be used. As for sustainable errors such as a
116 * single-shot I/O error, nilfs_err() should be used instead.
117 *
118 * Callers should not add a trailing newline since this will do it.
119 */
__nilfs_error(struct super_block * sb,const char * function,const char * fmt,...)120 void __nilfs_error(struct super_block *sb, const char *function,
121 const char *fmt, ...)
122 {
123 struct the_nilfs *nilfs = sb->s_fs_info;
124 struct va_format vaf;
125 va_list args;
126
127 va_start(args, fmt);
128
129 vaf.fmt = fmt;
130 vaf.va = &args;
131
132 printk(KERN_CRIT "NILFS error (device %s): %s: %pV\n",
133 sb->s_id, function, &vaf);
134
135 va_end(args);
136
137 if (!sb_rdonly(sb)) {
138 nilfs_set_error(sb);
139
140 if (nilfs_test_opt(nilfs, ERRORS_RO)) {
141 printk(KERN_CRIT "Remounting filesystem read-only\n");
142 sb->s_flags |= SB_RDONLY;
143 }
144 }
145
146 if (nilfs_test_opt(nilfs, ERRORS_PANIC))
147 panic("NILFS (device %s): panic forced after error\n",
148 sb->s_id);
149 }
150
nilfs_alloc_inode(struct super_block * sb)151 struct inode *nilfs_alloc_inode(struct super_block *sb)
152 {
153 struct nilfs_inode_info *ii;
154
155 ii = kmem_cache_alloc(nilfs_inode_cachep, GFP_NOFS);
156 if (!ii)
157 return NULL;
158 ii->i_bh = NULL;
159 ii->i_state = 0;
160 ii->i_cno = 0;
161 ii->i_assoc_inode = NULL;
162 ii->i_bmap = &ii->i_bmap_data;
163 return &ii->vfs_inode;
164 }
165
nilfs_free_inode(struct inode * inode)166 static void nilfs_free_inode(struct inode *inode)
167 {
168 if (nilfs_is_metadata_file_inode(inode))
169 nilfs_mdt_destroy(inode);
170
171 kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode));
172 }
173
nilfs_sync_super(struct super_block * sb,int flag)174 static int nilfs_sync_super(struct super_block *sb, int flag)
175 {
176 struct the_nilfs *nilfs = sb->s_fs_info;
177 int err;
178
179 retry:
180 set_buffer_dirty(nilfs->ns_sbh[0]);
181 if (nilfs_test_opt(nilfs, BARRIER)) {
182 err = __sync_dirty_buffer(nilfs->ns_sbh[0],
183 REQ_SYNC | REQ_PREFLUSH | REQ_FUA);
184 } else {
185 err = sync_dirty_buffer(nilfs->ns_sbh[0]);
186 }
187
188 if (unlikely(err)) {
189 nilfs_err(sb, "unable to write superblock: err=%d", err);
190 if (err == -EIO && nilfs->ns_sbh[1]) {
191 /*
192 * sbp[0] points to newer log than sbp[1],
193 * so copy sbp[0] to sbp[1] to take over sbp[0].
194 */
195 memcpy(nilfs->ns_sbp[1], nilfs->ns_sbp[0],
196 nilfs->ns_sbsize);
197 nilfs_fall_back_super_block(nilfs);
198 goto retry;
199 }
200 } else {
201 struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
202
203 nilfs->ns_sbwcount++;
204
205 /*
206 * The latest segment becomes trailable from the position
207 * written in superblock.
208 */
209 clear_nilfs_discontinued(nilfs);
210
211 /* update GC protection for recent segments */
212 if (nilfs->ns_sbh[1]) {
213 if (flag == NILFS_SB_COMMIT_ALL) {
214 set_buffer_dirty(nilfs->ns_sbh[1]);
215 if (sync_dirty_buffer(nilfs->ns_sbh[1]) < 0)
216 goto out;
217 }
218 if (le64_to_cpu(nilfs->ns_sbp[1]->s_last_cno) <
219 le64_to_cpu(nilfs->ns_sbp[0]->s_last_cno))
220 sbp = nilfs->ns_sbp[1];
221 }
222
223 spin_lock(&nilfs->ns_last_segment_lock);
224 nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq);
225 spin_unlock(&nilfs->ns_last_segment_lock);
226 }
227 out:
228 return err;
229 }
230
nilfs_set_log_cursor(struct nilfs_super_block * sbp,struct the_nilfs * nilfs)231 void nilfs_set_log_cursor(struct nilfs_super_block *sbp,
232 struct the_nilfs *nilfs)
233 {
234 sector_t nfreeblocks;
235
236 /* nilfs->ns_sem must be locked by the caller. */
237 nilfs_count_free_blocks(nilfs, &nfreeblocks);
238 sbp->s_free_blocks_count = cpu_to_le64(nfreeblocks);
239
240 spin_lock(&nilfs->ns_last_segment_lock);
241 sbp->s_last_seq = cpu_to_le64(nilfs->ns_last_seq);
242 sbp->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg);
243 sbp->s_last_cno = cpu_to_le64(nilfs->ns_last_cno);
244 spin_unlock(&nilfs->ns_last_segment_lock);
245 }
246
nilfs_prepare_super(struct super_block * sb,int flip)247 struct nilfs_super_block **nilfs_prepare_super(struct super_block *sb,
248 int flip)
249 {
250 struct the_nilfs *nilfs = sb->s_fs_info;
251 struct nilfs_super_block **sbp = nilfs->ns_sbp;
252
253 /* nilfs->ns_sem must be locked by the caller. */
254 if (sbp[0]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
255 if (sbp[1] &&
256 sbp[1]->s_magic == cpu_to_le16(NILFS_SUPER_MAGIC)) {
257 memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
258 } else {
259 nilfs_crit(sb, "superblock broke");
260 return NULL;
261 }
262 } else if (sbp[1] &&
263 sbp[1]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
264 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
265 }
266
267 if (flip && sbp[1])
268 nilfs_swap_super_block(nilfs);
269
270 return sbp;
271 }
272
nilfs_commit_super(struct super_block * sb,int flag)273 int nilfs_commit_super(struct super_block *sb, int flag)
274 {
275 struct the_nilfs *nilfs = sb->s_fs_info;
276 struct nilfs_super_block **sbp = nilfs->ns_sbp;
277 time64_t t;
278
279 /* nilfs->ns_sem must be locked by the caller. */
280 t = ktime_get_real_seconds();
281 nilfs->ns_sbwtime = t;
282 sbp[0]->s_wtime = cpu_to_le64(t);
283 sbp[0]->s_sum = 0;
284 sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
285 (unsigned char *)sbp[0],
286 nilfs->ns_sbsize));
287 if (flag == NILFS_SB_COMMIT_ALL && sbp[1]) {
288 sbp[1]->s_wtime = sbp[0]->s_wtime;
289 sbp[1]->s_sum = 0;
290 sbp[1]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
291 (unsigned char *)sbp[1],
292 nilfs->ns_sbsize));
293 }
294 clear_nilfs_sb_dirty(nilfs);
295 nilfs->ns_flushed_device = 1;
296 /* make sure store to ns_flushed_device cannot be reordered */
297 smp_wmb();
298 return nilfs_sync_super(sb, flag);
299 }
300
301 /**
302 * nilfs_cleanup_super() - write filesystem state for cleanup
303 * @sb: super block instance to be unmounted or degraded to read-only
304 *
305 * This function restores state flags in the on-disk super block.
306 * This will set "clean" flag (i.e. NILFS_VALID_FS) unless the
307 * filesystem was not clean previously.
308 */
nilfs_cleanup_super(struct super_block * sb)309 int nilfs_cleanup_super(struct super_block *sb)
310 {
311 struct the_nilfs *nilfs = sb->s_fs_info;
312 struct nilfs_super_block **sbp;
313 int flag = NILFS_SB_COMMIT;
314 int ret = -EIO;
315
316 sbp = nilfs_prepare_super(sb, 0);
317 if (sbp) {
318 sbp[0]->s_state = cpu_to_le16(nilfs->ns_mount_state);
319 nilfs_set_log_cursor(sbp[0], nilfs);
320 if (sbp[1] && sbp[0]->s_last_cno == sbp[1]->s_last_cno) {
321 /*
322 * make the "clean" flag also to the opposite
323 * super block if both super blocks point to
324 * the same checkpoint.
325 */
326 sbp[1]->s_state = sbp[0]->s_state;
327 flag = NILFS_SB_COMMIT_ALL;
328 }
329 ret = nilfs_commit_super(sb, flag);
330 }
331 return ret;
332 }
333
334 /**
335 * nilfs_move_2nd_super - relocate secondary super block
336 * @sb: super block instance
337 * @sb2off: new offset of the secondary super block (in bytes)
338 */
nilfs_move_2nd_super(struct super_block * sb,loff_t sb2off)339 static int nilfs_move_2nd_super(struct super_block *sb, loff_t sb2off)
340 {
341 struct the_nilfs *nilfs = sb->s_fs_info;
342 struct buffer_head *nsbh;
343 struct nilfs_super_block *nsbp;
344 sector_t blocknr, newblocknr;
345 unsigned long offset;
346 int sb2i; /* array index of the secondary superblock */
347 int ret = 0;
348
349 /* nilfs->ns_sem must be locked by the caller. */
350 if (nilfs->ns_sbh[1] &&
351 nilfs->ns_sbh[1]->b_blocknr > nilfs->ns_first_data_block) {
352 sb2i = 1;
353 blocknr = nilfs->ns_sbh[1]->b_blocknr;
354 } else if (nilfs->ns_sbh[0]->b_blocknr > nilfs->ns_first_data_block) {
355 sb2i = 0;
356 blocknr = nilfs->ns_sbh[0]->b_blocknr;
357 } else {
358 sb2i = -1;
359 blocknr = 0;
360 }
361 if (sb2i >= 0 && (u64)blocknr << nilfs->ns_blocksize_bits == sb2off)
362 goto out; /* super block location is unchanged */
363
364 /* Get new super block buffer */
365 newblocknr = sb2off >> nilfs->ns_blocksize_bits;
366 offset = sb2off & (nilfs->ns_blocksize - 1);
367 nsbh = sb_getblk(sb, newblocknr);
368 if (!nsbh) {
369 nilfs_warn(sb,
370 "unable to move secondary superblock to block %llu",
371 (unsigned long long)newblocknr);
372 ret = -EIO;
373 goto out;
374 }
375 nsbp = (void *)nsbh->b_data + offset;
376 memset(nsbp, 0, nilfs->ns_blocksize);
377
378 if (sb2i >= 0) {
379 memcpy(nsbp, nilfs->ns_sbp[sb2i], nilfs->ns_sbsize);
380 brelse(nilfs->ns_sbh[sb2i]);
381 nilfs->ns_sbh[sb2i] = nsbh;
382 nilfs->ns_sbp[sb2i] = nsbp;
383 } else if (nilfs->ns_sbh[0]->b_blocknr < nilfs->ns_first_data_block) {
384 /* secondary super block will be restored to index 1 */
385 nilfs->ns_sbh[1] = nsbh;
386 nilfs->ns_sbp[1] = nsbp;
387 } else {
388 brelse(nsbh);
389 }
390 out:
391 return ret;
392 }
393
394 /**
395 * nilfs_resize_fs - resize the filesystem
396 * @sb: super block instance
397 * @newsize: new size of the filesystem (in bytes)
398 */
nilfs_resize_fs(struct super_block * sb,__u64 newsize)399 int nilfs_resize_fs(struct super_block *sb, __u64 newsize)
400 {
401 struct the_nilfs *nilfs = sb->s_fs_info;
402 struct nilfs_super_block **sbp;
403 __u64 devsize, newnsegs;
404 loff_t sb2off;
405 int ret;
406
407 ret = -ERANGE;
408 devsize = i_size_read(sb->s_bdev->bd_inode);
409 if (newsize > devsize)
410 goto out;
411
412 /*
413 * Write lock is required to protect some functions depending
414 * on the number of segments, the number of reserved segments,
415 * and so forth.
416 */
417 down_write(&nilfs->ns_segctor_sem);
418
419 sb2off = NILFS_SB2_OFFSET_BYTES(newsize);
420 newnsegs = sb2off >> nilfs->ns_blocksize_bits;
421 do_div(newnsegs, nilfs->ns_blocks_per_segment);
422
423 ret = nilfs_sufile_resize(nilfs->ns_sufile, newnsegs);
424 up_write(&nilfs->ns_segctor_sem);
425 if (ret < 0)
426 goto out;
427
428 ret = nilfs_construct_segment(sb);
429 if (ret < 0)
430 goto out;
431
432 down_write(&nilfs->ns_sem);
433 nilfs_move_2nd_super(sb, sb2off);
434 ret = -EIO;
435 sbp = nilfs_prepare_super(sb, 0);
436 if (likely(sbp)) {
437 nilfs_set_log_cursor(sbp[0], nilfs);
438 /*
439 * Drop NILFS_RESIZE_FS flag for compatibility with
440 * mount-time resize which may be implemented in a
441 * future release.
442 */
443 sbp[0]->s_state = cpu_to_le16(le16_to_cpu(sbp[0]->s_state) &
444 ~NILFS_RESIZE_FS);
445 sbp[0]->s_dev_size = cpu_to_le64(newsize);
446 sbp[0]->s_nsegments = cpu_to_le64(nilfs->ns_nsegments);
447 if (sbp[1])
448 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
449 ret = nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
450 }
451 up_write(&nilfs->ns_sem);
452
453 /*
454 * Reset the range of allocatable segments last. This order
455 * is important in the case of expansion because the secondary
456 * superblock must be protected from log write until migration
457 * completes.
458 */
459 if (!ret)
460 nilfs_sufile_set_alloc_range(nilfs->ns_sufile, 0, newnsegs - 1);
461 out:
462 return ret;
463 }
464
nilfs_put_super(struct super_block * sb)465 static void nilfs_put_super(struct super_block *sb)
466 {
467 struct the_nilfs *nilfs = sb->s_fs_info;
468
469 nilfs_detach_log_writer(sb);
470
471 if (!sb_rdonly(sb)) {
472 down_write(&nilfs->ns_sem);
473 nilfs_cleanup_super(sb);
474 up_write(&nilfs->ns_sem);
475 }
476
477 iput(nilfs->ns_sufile);
478 iput(nilfs->ns_cpfile);
479 iput(nilfs->ns_dat);
480
481 destroy_nilfs(nilfs);
482 sb->s_fs_info = NULL;
483 }
484
nilfs_sync_fs(struct super_block * sb,int wait)485 static int nilfs_sync_fs(struct super_block *sb, int wait)
486 {
487 struct the_nilfs *nilfs = sb->s_fs_info;
488 struct nilfs_super_block **sbp;
489 int err = 0;
490
491 /* This function is called when super block should be written back */
492 if (wait)
493 err = nilfs_construct_segment(sb);
494
495 down_write(&nilfs->ns_sem);
496 if (nilfs_sb_dirty(nilfs)) {
497 sbp = nilfs_prepare_super(sb, nilfs_sb_will_flip(nilfs));
498 if (likely(sbp)) {
499 nilfs_set_log_cursor(sbp[0], nilfs);
500 nilfs_commit_super(sb, NILFS_SB_COMMIT);
501 }
502 }
503 up_write(&nilfs->ns_sem);
504
505 if (!err)
506 err = nilfs_flush_device(nilfs);
507
508 return err;
509 }
510
nilfs_attach_checkpoint(struct super_block * sb,__u64 cno,int curr_mnt,struct nilfs_root ** rootp)511 int nilfs_attach_checkpoint(struct super_block *sb, __u64 cno, int curr_mnt,
512 struct nilfs_root **rootp)
513 {
514 struct the_nilfs *nilfs = sb->s_fs_info;
515 struct nilfs_root *root;
516 struct nilfs_checkpoint *raw_cp;
517 struct buffer_head *bh_cp;
518 int err = -ENOMEM;
519
520 root = nilfs_find_or_create_root(
521 nilfs, curr_mnt ? NILFS_CPTREE_CURRENT_CNO : cno);
522 if (!root)
523 return err;
524
525 if (root->ifile)
526 goto reuse; /* already attached checkpoint */
527
528 down_read(&nilfs->ns_segctor_sem);
529 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp,
530 &bh_cp);
531 up_read(&nilfs->ns_segctor_sem);
532 if (unlikely(err)) {
533 if (err == -ENOENT || err == -EINVAL) {
534 nilfs_err(sb,
535 "Invalid checkpoint (checkpoint number=%llu)",
536 (unsigned long long)cno);
537 err = -EINVAL;
538 }
539 goto failed;
540 }
541
542 err = nilfs_ifile_read(sb, root, nilfs->ns_inode_size,
543 &raw_cp->cp_ifile_inode, &root->ifile);
544 if (err)
545 goto failed_bh;
546
547 atomic64_set(&root->inodes_count,
548 le64_to_cpu(raw_cp->cp_inodes_count));
549 atomic64_set(&root->blocks_count,
550 le64_to_cpu(raw_cp->cp_blocks_count));
551
552 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
553
554 reuse:
555 *rootp = root;
556 return 0;
557
558 failed_bh:
559 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
560 failed:
561 nilfs_put_root(root);
562
563 return err;
564 }
565
nilfs_freeze(struct super_block * sb)566 static int nilfs_freeze(struct super_block *sb)
567 {
568 struct the_nilfs *nilfs = sb->s_fs_info;
569 int err;
570
571 if (sb_rdonly(sb))
572 return 0;
573
574 /* Mark super block clean */
575 down_write(&nilfs->ns_sem);
576 err = nilfs_cleanup_super(sb);
577 up_write(&nilfs->ns_sem);
578 return err;
579 }
580
nilfs_unfreeze(struct super_block * sb)581 static int nilfs_unfreeze(struct super_block *sb)
582 {
583 struct the_nilfs *nilfs = sb->s_fs_info;
584
585 if (sb_rdonly(sb))
586 return 0;
587
588 down_write(&nilfs->ns_sem);
589 nilfs_setup_super(sb, false);
590 up_write(&nilfs->ns_sem);
591 return 0;
592 }
593
nilfs_statfs(struct dentry * dentry,struct kstatfs * buf)594 static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
595 {
596 struct super_block *sb = dentry->d_sb;
597 struct nilfs_root *root = NILFS_I(d_inode(dentry))->i_root;
598 struct the_nilfs *nilfs = root->nilfs;
599 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
600 unsigned long long blocks;
601 unsigned long overhead;
602 unsigned long nrsvblocks;
603 sector_t nfreeblocks;
604 u64 nmaxinodes, nfreeinodes;
605 int err;
606
607 /*
608 * Compute all of the segment blocks
609 *
610 * The blocks before first segment and after last segment
611 * are excluded.
612 */
613 blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments
614 - nilfs->ns_first_data_block;
615 nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment;
616
617 /*
618 * Compute the overhead
619 *
620 * When distributing meta data blocks outside segment structure,
621 * We must count them as the overhead.
622 */
623 overhead = 0;
624
625 err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
626 if (unlikely(err))
627 return err;
628
629 err = nilfs_ifile_count_free_inodes(root->ifile,
630 &nmaxinodes, &nfreeinodes);
631 if (unlikely(err)) {
632 nilfs_warn(sb, "failed to count free inodes: err=%d", err);
633 if (err == -ERANGE) {
634 /*
635 * If nilfs_palloc_count_max_entries() returns
636 * -ERANGE error code then we simply treat
637 * curent inodes count as maximum possible and
638 * zero as free inodes value.
639 */
640 nmaxinodes = atomic64_read(&root->inodes_count);
641 nfreeinodes = 0;
642 err = 0;
643 } else
644 return err;
645 }
646
647 buf->f_type = NILFS_SUPER_MAGIC;
648 buf->f_bsize = sb->s_blocksize;
649 buf->f_blocks = blocks - overhead;
650 buf->f_bfree = nfreeblocks;
651 buf->f_bavail = (buf->f_bfree >= nrsvblocks) ?
652 (buf->f_bfree - nrsvblocks) : 0;
653 buf->f_files = nmaxinodes;
654 buf->f_ffree = nfreeinodes;
655 buf->f_namelen = NILFS_NAME_LEN;
656 buf->f_fsid = u64_to_fsid(id);
657
658 return 0;
659 }
660
nilfs_show_options(struct seq_file * seq,struct dentry * dentry)661 static int nilfs_show_options(struct seq_file *seq, struct dentry *dentry)
662 {
663 struct super_block *sb = dentry->d_sb;
664 struct the_nilfs *nilfs = sb->s_fs_info;
665 struct nilfs_root *root = NILFS_I(d_inode(dentry))->i_root;
666
667 if (!nilfs_test_opt(nilfs, BARRIER))
668 seq_puts(seq, ",nobarrier");
669 if (root->cno != NILFS_CPTREE_CURRENT_CNO)
670 seq_printf(seq, ",cp=%llu", (unsigned long long)root->cno);
671 if (nilfs_test_opt(nilfs, ERRORS_PANIC))
672 seq_puts(seq, ",errors=panic");
673 if (nilfs_test_opt(nilfs, ERRORS_CONT))
674 seq_puts(seq, ",errors=continue");
675 if (nilfs_test_opt(nilfs, STRICT_ORDER))
676 seq_puts(seq, ",order=strict");
677 if (nilfs_test_opt(nilfs, NORECOVERY))
678 seq_puts(seq, ",norecovery");
679 if (nilfs_test_opt(nilfs, DISCARD))
680 seq_puts(seq, ",discard");
681
682 return 0;
683 }
684
685 static const struct super_operations nilfs_sops = {
686 .alloc_inode = nilfs_alloc_inode,
687 .free_inode = nilfs_free_inode,
688 .dirty_inode = nilfs_dirty_inode,
689 .evict_inode = nilfs_evict_inode,
690 .put_super = nilfs_put_super,
691 .sync_fs = nilfs_sync_fs,
692 .freeze_fs = nilfs_freeze,
693 .unfreeze_fs = nilfs_unfreeze,
694 .statfs = nilfs_statfs,
695 .remount_fs = nilfs_remount,
696 .show_options = nilfs_show_options
697 };
698
699 enum {
700 Opt_err_cont, Opt_err_panic, Opt_err_ro,
701 Opt_barrier, Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery,
702 Opt_discard, Opt_nodiscard, Opt_err,
703 };
704
705 static match_table_t tokens = {
706 {Opt_err_cont, "errors=continue"},
707 {Opt_err_panic, "errors=panic"},
708 {Opt_err_ro, "errors=remount-ro"},
709 {Opt_barrier, "barrier"},
710 {Opt_nobarrier, "nobarrier"},
711 {Opt_snapshot, "cp=%u"},
712 {Opt_order, "order=%s"},
713 {Opt_norecovery, "norecovery"},
714 {Opt_discard, "discard"},
715 {Opt_nodiscard, "nodiscard"},
716 {Opt_err, NULL}
717 };
718
parse_options(char * options,struct super_block * sb,int is_remount)719 static int parse_options(char *options, struct super_block *sb, int is_remount)
720 {
721 struct the_nilfs *nilfs = sb->s_fs_info;
722 char *p;
723 substring_t args[MAX_OPT_ARGS];
724
725 if (!options)
726 return 1;
727
728 while ((p = strsep(&options, ",")) != NULL) {
729 int token;
730
731 if (!*p)
732 continue;
733
734 token = match_token(p, tokens, args);
735 switch (token) {
736 case Opt_barrier:
737 nilfs_set_opt(nilfs, BARRIER);
738 break;
739 case Opt_nobarrier:
740 nilfs_clear_opt(nilfs, BARRIER);
741 break;
742 case Opt_order:
743 if (strcmp(args[0].from, "relaxed") == 0)
744 /* Ordered data semantics */
745 nilfs_clear_opt(nilfs, STRICT_ORDER);
746 else if (strcmp(args[0].from, "strict") == 0)
747 /* Strict in-order semantics */
748 nilfs_set_opt(nilfs, STRICT_ORDER);
749 else
750 return 0;
751 break;
752 case Opt_err_panic:
753 nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_PANIC);
754 break;
755 case Opt_err_ro:
756 nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_RO);
757 break;
758 case Opt_err_cont:
759 nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_CONT);
760 break;
761 case Opt_snapshot:
762 if (is_remount) {
763 nilfs_err(sb,
764 "\"%s\" option is invalid for remount",
765 p);
766 return 0;
767 }
768 break;
769 case Opt_norecovery:
770 nilfs_set_opt(nilfs, NORECOVERY);
771 break;
772 case Opt_discard:
773 nilfs_set_opt(nilfs, DISCARD);
774 break;
775 case Opt_nodiscard:
776 nilfs_clear_opt(nilfs, DISCARD);
777 break;
778 default:
779 nilfs_err(sb, "unrecognized mount option \"%s\"", p);
780 return 0;
781 }
782 }
783 return 1;
784 }
785
786 static inline void
nilfs_set_default_options(struct super_block * sb,struct nilfs_super_block * sbp)787 nilfs_set_default_options(struct super_block *sb,
788 struct nilfs_super_block *sbp)
789 {
790 struct the_nilfs *nilfs = sb->s_fs_info;
791
792 nilfs->ns_mount_opt =
793 NILFS_MOUNT_ERRORS_RO | NILFS_MOUNT_BARRIER;
794 }
795
nilfs_setup_super(struct super_block * sb,int is_mount)796 static int nilfs_setup_super(struct super_block *sb, int is_mount)
797 {
798 struct the_nilfs *nilfs = sb->s_fs_info;
799 struct nilfs_super_block **sbp;
800 int max_mnt_count;
801 int mnt_count;
802
803 /* nilfs->ns_sem must be locked by the caller. */
804 sbp = nilfs_prepare_super(sb, 0);
805 if (!sbp)
806 return -EIO;
807
808 if (!is_mount)
809 goto skip_mount_setup;
810
811 max_mnt_count = le16_to_cpu(sbp[0]->s_max_mnt_count);
812 mnt_count = le16_to_cpu(sbp[0]->s_mnt_count);
813
814 if (nilfs->ns_mount_state & NILFS_ERROR_FS) {
815 nilfs_warn(sb, "mounting fs with errors");
816 #if 0
817 } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) {
818 nilfs_warn(sb, "maximal mount count reached");
819 #endif
820 }
821 if (!max_mnt_count)
822 sbp[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT);
823
824 sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1);
825 sbp[0]->s_mtime = cpu_to_le64(ktime_get_real_seconds());
826
827 skip_mount_setup:
828 sbp[0]->s_state =
829 cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS);
830 /* synchronize sbp[1] with sbp[0] */
831 if (sbp[1])
832 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
833 return nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
834 }
835
nilfs_read_super_block(struct super_block * sb,u64 pos,int blocksize,struct buffer_head ** pbh)836 struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb,
837 u64 pos, int blocksize,
838 struct buffer_head **pbh)
839 {
840 unsigned long long sb_index = pos;
841 unsigned long offset;
842
843 offset = do_div(sb_index, blocksize);
844 *pbh = sb_bread(sb, sb_index);
845 if (!*pbh)
846 return NULL;
847 return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset);
848 }
849
nilfs_store_magic_and_option(struct super_block * sb,struct nilfs_super_block * sbp,char * data)850 int nilfs_store_magic_and_option(struct super_block *sb,
851 struct nilfs_super_block *sbp,
852 char *data)
853 {
854 struct the_nilfs *nilfs = sb->s_fs_info;
855
856 sb->s_magic = le16_to_cpu(sbp->s_magic);
857
858 /* FS independent flags */
859 #ifdef NILFS_ATIME_DISABLE
860 sb->s_flags |= SB_NOATIME;
861 #endif
862
863 nilfs_set_default_options(sb, sbp);
864
865 nilfs->ns_resuid = le16_to_cpu(sbp->s_def_resuid);
866 nilfs->ns_resgid = le16_to_cpu(sbp->s_def_resgid);
867 nilfs->ns_interval = le32_to_cpu(sbp->s_c_interval);
868 nilfs->ns_watermark = le32_to_cpu(sbp->s_c_block_max);
869
870 return !parse_options(data, sb, 0) ? -EINVAL : 0;
871 }
872
nilfs_check_feature_compatibility(struct super_block * sb,struct nilfs_super_block * sbp)873 int nilfs_check_feature_compatibility(struct super_block *sb,
874 struct nilfs_super_block *sbp)
875 {
876 __u64 features;
877
878 features = le64_to_cpu(sbp->s_feature_incompat) &
879 ~NILFS_FEATURE_INCOMPAT_SUPP;
880 if (features) {
881 nilfs_err(sb,
882 "couldn't mount because of unsupported optional features (%llx)",
883 (unsigned long long)features);
884 return -EINVAL;
885 }
886 features = le64_to_cpu(sbp->s_feature_compat_ro) &
887 ~NILFS_FEATURE_COMPAT_RO_SUPP;
888 if (!sb_rdonly(sb) && features) {
889 nilfs_err(sb,
890 "couldn't mount RDWR because of unsupported optional features (%llx)",
891 (unsigned long long)features);
892 return -EINVAL;
893 }
894 return 0;
895 }
896
nilfs_get_root_dentry(struct super_block * sb,struct nilfs_root * root,struct dentry ** root_dentry)897 static int nilfs_get_root_dentry(struct super_block *sb,
898 struct nilfs_root *root,
899 struct dentry **root_dentry)
900 {
901 struct inode *inode;
902 struct dentry *dentry;
903 int ret = 0;
904
905 inode = nilfs_iget(sb, root, NILFS_ROOT_INO);
906 if (IS_ERR(inode)) {
907 ret = PTR_ERR(inode);
908 nilfs_err(sb, "error %d getting root inode", ret);
909 goto out;
910 }
911 if (!S_ISDIR(inode->i_mode) || !inode->i_blocks || !inode->i_size) {
912 iput(inode);
913 nilfs_err(sb, "corrupt root inode");
914 ret = -EINVAL;
915 goto out;
916 }
917
918 if (root->cno == NILFS_CPTREE_CURRENT_CNO) {
919 dentry = d_find_alias(inode);
920 if (!dentry) {
921 dentry = d_make_root(inode);
922 if (!dentry) {
923 ret = -ENOMEM;
924 goto failed_dentry;
925 }
926 } else {
927 iput(inode);
928 }
929 } else {
930 dentry = d_obtain_root(inode);
931 if (IS_ERR(dentry)) {
932 ret = PTR_ERR(dentry);
933 goto failed_dentry;
934 }
935 }
936 *root_dentry = dentry;
937 out:
938 return ret;
939
940 failed_dentry:
941 nilfs_err(sb, "error %d getting root dentry", ret);
942 goto out;
943 }
944
nilfs_attach_snapshot(struct super_block * s,__u64 cno,struct dentry ** root_dentry)945 static int nilfs_attach_snapshot(struct super_block *s, __u64 cno,
946 struct dentry **root_dentry)
947 {
948 struct the_nilfs *nilfs = s->s_fs_info;
949 struct nilfs_root *root;
950 int ret;
951
952 mutex_lock(&nilfs->ns_snapshot_mount_mutex);
953
954 down_read(&nilfs->ns_segctor_sem);
955 ret = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile, cno);
956 up_read(&nilfs->ns_segctor_sem);
957 if (ret < 0) {
958 ret = (ret == -ENOENT) ? -EINVAL : ret;
959 goto out;
960 } else if (!ret) {
961 nilfs_err(s,
962 "The specified checkpoint is not a snapshot (checkpoint number=%llu)",
963 (unsigned long long)cno);
964 ret = -EINVAL;
965 goto out;
966 }
967
968 ret = nilfs_attach_checkpoint(s, cno, false, &root);
969 if (ret) {
970 nilfs_err(s,
971 "error %d while loading snapshot (checkpoint number=%llu)",
972 ret, (unsigned long long)cno);
973 goto out;
974 }
975 ret = nilfs_get_root_dentry(s, root, root_dentry);
976 nilfs_put_root(root);
977 out:
978 mutex_unlock(&nilfs->ns_snapshot_mount_mutex);
979 return ret;
980 }
981
982 /**
983 * nilfs_tree_is_busy() - try to shrink dentries of a checkpoint
984 * @root_dentry: root dentry of the tree to be shrunk
985 *
986 * This function returns true if the tree was in-use.
987 */
nilfs_tree_is_busy(struct dentry * root_dentry)988 static bool nilfs_tree_is_busy(struct dentry *root_dentry)
989 {
990 shrink_dcache_parent(root_dentry);
991 return d_count(root_dentry) > 1;
992 }
993
nilfs_checkpoint_is_mounted(struct super_block * sb,__u64 cno)994 int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno)
995 {
996 struct the_nilfs *nilfs = sb->s_fs_info;
997 struct nilfs_root *root;
998 struct inode *inode;
999 struct dentry *dentry;
1000 int ret;
1001
1002 if (cno > nilfs->ns_cno)
1003 return false;
1004
1005 if (cno >= nilfs_last_cno(nilfs))
1006 return true; /* protect recent checkpoints */
1007
1008 ret = false;
1009 root = nilfs_lookup_root(nilfs, cno);
1010 if (root) {
1011 inode = nilfs_ilookup(sb, root, NILFS_ROOT_INO);
1012 if (inode) {
1013 dentry = d_find_alias(inode);
1014 if (dentry) {
1015 ret = nilfs_tree_is_busy(dentry);
1016 dput(dentry);
1017 }
1018 iput(inode);
1019 }
1020 nilfs_put_root(root);
1021 }
1022 return ret;
1023 }
1024
1025 /**
1026 * nilfs_fill_super() - initialize a super block instance
1027 * @sb: super_block
1028 * @data: mount options
1029 * @silent: silent mode flag
1030 *
1031 * This function is called exclusively by nilfs->ns_mount_mutex.
1032 * So, the recovery process is protected from other simultaneous mounts.
1033 */
1034 static int
nilfs_fill_super(struct super_block * sb,void * data,int silent)1035 nilfs_fill_super(struct super_block *sb, void *data, int silent)
1036 {
1037 struct the_nilfs *nilfs;
1038 struct nilfs_root *fsroot;
1039 __u64 cno;
1040 int err;
1041
1042 nilfs = alloc_nilfs(sb);
1043 if (!nilfs)
1044 return -ENOMEM;
1045
1046 sb->s_fs_info = nilfs;
1047
1048 err = init_nilfs(nilfs, sb, (char *)data);
1049 if (err)
1050 goto failed_nilfs;
1051
1052 sb->s_op = &nilfs_sops;
1053 sb->s_export_op = &nilfs_export_ops;
1054 sb->s_root = NULL;
1055 sb->s_time_gran = 1;
1056 sb->s_max_links = NILFS_LINK_MAX;
1057
1058 sb->s_bdi = bdi_get(sb->s_bdev->bd_bdi);
1059
1060 err = load_nilfs(nilfs, sb);
1061 if (err)
1062 goto failed_nilfs;
1063
1064 cno = nilfs_last_cno(nilfs);
1065 err = nilfs_attach_checkpoint(sb, cno, true, &fsroot);
1066 if (err) {
1067 nilfs_err(sb,
1068 "error %d while loading last checkpoint (checkpoint number=%llu)",
1069 err, (unsigned long long)cno);
1070 goto failed_unload;
1071 }
1072
1073 if (!sb_rdonly(sb)) {
1074 err = nilfs_attach_log_writer(sb, fsroot);
1075 if (err)
1076 goto failed_checkpoint;
1077 }
1078
1079 err = nilfs_get_root_dentry(sb, fsroot, &sb->s_root);
1080 if (err)
1081 goto failed_segctor;
1082
1083 nilfs_put_root(fsroot);
1084
1085 if (!sb_rdonly(sb)) {
1086 down_write(&nilfs->ns_sem);
1087 nilfs_setup_super(sb, true);
1088 up_write(&nilfs->ns_sem);
1089 }
1090
1091 return 0;
1092
1093 failed_segctor:
1094 nilfs_detach_log_writer(sb);
1095
1096 failed_checkpoint:
1097 nilfs_put_root(fsroot);
1098
1099 failed_unload:
1100 iput(nilfs->ns_sufile);
1101 iput(nilfs->ns_cpfile);
1102 iput(nilfs->ns_dat);
1103
1104 failed_nilfs:
1105 destroy_nilfs(nilfs);
1106 return err;
1107 }
1108
nilfs_remount(struct super_block * sb,int * flags,char * data)1109 static int nilfs_remount(struct super_block *sb, int *flags, char *data)
1110 {
1111 struct the_nilfs *nilfs = sb->s_fs_info;
1112 unsigned long old_sb_flags;
1113 unsigned long old_mount_opt;
1114 int err;
1115
1116 sync_filesystem(sb);
1117 old_sb_flags = sb->s_flags;
1118 old_mount_opt = nilfs->ns_mount_opt;
1119
1120 if (!parse_options(data, sb, 1)) {
1121 err = -EINVAL;
1122 goto restore_opts;
1123 }
1124 sb->s_flags = (sb->s_flags & ~SB_POSIXACL);
1125
1126 err = -EINVAL;
1127
1128 if (!nilfs_valid_fs(nilfs)) {
1129 nilfs_warn(sb,
1130 "couldn't remount because the filesystem is in an incomplete recovery state");
1131 goto restore_opts;
1132 }
1133
1134 if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1135 goto out;
1136 if (*flags & SB_RDONLY) {
1137 sb->s_flags |= SB_RDONLY;
1138
1139 /*
1140 * Remounting a valid RW partition RDONLY, so set
1141 * the RDONLY flag and then mark the partition as valid again.
1142 */
1143 down_write(&nilfs->ns_sem);
1144 nilfs_cleanup_super(sb);
1145 up_write(&nilfs->ns_sem);
1146 } else {
1147 __u64 features;
1148 struct nilfs_root *root;
1149
1150 /*
1151 * Mounting a RDONLY partition read-write, so reread and
1152 * store the current valid flag. (It may have been changed
1153 * by fsck since we originally mounted the partition.)
1154 */
1155 down_read(&nilfs->ns_sem);
1156 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
1157 ~NILFS_FEATURE_COMPAT_RO_SUPP;
1158 up_read(&nilfs->ns_sem);
1159 if (features) {
1160 nilfs_warn(sb,
1161 "couldn't remount RDWR because of unsupported optional features (%llx)",
1162 (unsigned long long)features);
1163 err = -EROFS;
1164 goto restore_opts;
1165 }
1166
1167 sb->s_flags &= ~SB_RDONLY;
1168
1169 root = NILFS_I(d_inode(sb->s_root))->i_root;
1170 err = nilfs_attach_log_writer(sb, root);
1171 if (err)
1172 goto restore_opts;
1173
1174 down_write(&nilfs->ns_sem);
1175 nilfs_setup_super(sb, true);
1176 up_write(&nilfs->ns_sem);
1177 }
1178 out:
1179 return 0;
1180
1181 restore_opts:
1182 sb->s_flags = old_sb_flags;
1183 nilfs->ns_mount_opt = old_mount_opt;
1184 return err;
1185 }
1186
1187 struct nilfs_super_data {
1188 struct block_device *bdev;
1189 __u64 cno;
1190 int flags;
1191 };
1192
nilfs_parse_snapshot_option(const char * option,const substring_t * arg,struct nilfs_super_data * sd)1193 static int nilfs_parse_snapshot_option(const char *option,
1194 const substring_t *arg,
1195 struct nilfs_super_data *sd)
1196 {
1197 unsigned long long val;
1198 const char *msg = NULL;
1199 int err;
1200
1201 if (!(sd->flags & SB_RDONLY)) {
1202 msg = "read-only option is not specified";
1203 goto parse_error;
1204 }
1205
1206 err = kstrtoull(arg->from, 0, &val);
1207 if (err) {
1208 if (err == -ERANGE)
1209 msg = "too large checkpoint number";
1210 else
1211 msg = "malformed argument";
1212 goto parse_error;
1213 } else if (val == 0) {
1214 msg = "invalid checkpoint number 0";
1215 goto parse_error;
1216 }
1217 sd->cno = val;
1218 return 0;
1219
1220 parse_error:
1221 nilfs_err(NULL, "invalid option \"%s\": %s", option, msg);
1222 return 1;
1223 }
1224
1225 /**
1226 * nilfs_identify - pre-read mount options needed to identify mount instance
1227 * @data: mount options
1228 * @sd: nilfs_super_data
1229 */
nilfs_identify(char * data,struct nilfs_super_data * sd)1230 static int nilfs_identify(char *data, struct nilfs_super_data *sd)
1231 {
1232 char *p, *options = data;
1233 substring_t args[MAX_OPT_ARGS];
1234 int token;
1235 int ret = 0;
1236
1237 do {
1238 p = strsep(&options, ",");
1239 if (p != NULL && *p) {
1240 token = match_token(p, tokens, args);
1241 if (token == Opt_snapshot)
1242 ret = nilfs_parse_snapshot_option(p, &args[0],
1243 sd);
1244 }
1245 if (!options)
1246 break;
1247 BUG_ON(options == data);
1248 *(options - 1) = ',';
1249 } while (!ret);
1250 return ret;
1251 }
1252
nilfs_set_bdev_super(struct super_block * s,void * data)1253 static int nilfs_set_bdev_super(struct super_block *s, void *data)
1254 {
1255 s->s_bdev = data;
1256 s->s_dev = s->s_bdev->bd_dev;
1257 return 0;
1258 }
1259
nilfs_test_bdev_super(struct super_block * s,void * data)1260 static int nilfs_test_bdev_super(struct super_block *s, void *data)
1261 {
1262 return (void *)s->s_bdev == data;
1263 }
1264
1265 static struct dentry *
nilfs_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)1266 nilfs_mount(struct file_system_type *fs_type, int flags,
1267 const char *dev_name, void *data)
1268 {
1269 struct nilfs_super_data sd;
1270 struct super_block *s;
1271 fmode_t mode = FMODE_READ | FMODE_EXCL;
1272 struct dentry *root_dentry;
1273 int err, s_new = false;
1274
1275 if (!(flags & SB_RDONLY))
1276 mode |= FMODE_WRITE;
1277
1278 sd.bdev = blkdev_get_by_path(dev_name, mode, fs_type);
1279 if (IS_ERR(sd.bdev))
1280 return ERR_CAST(sd.bdev);
1281
1282 sd.cno = 0;
1283 sd.flags = flags;
1284 if (nilfs_identify((char *)data, &sd)) {
1285 err = -EINVAL;
1286 goto failed;
1287 }
1288
1289 /*
1290 * once the super is inserted into the list by sget, s_umount
1291 * will protect the lockfs code from trying to start a snapshot
1292 * while we are mounting
1293 */
1294 mutex_lock(&sd.bdev->bd_fsfreeze_mutex);
1295 if (sd.bdev->bd_fsfreeze_count > 0) {
1296 mutex_unlock(&sd.bdev->bd_fsfreeze_mutex);
1297 err = -EBUSY;
1298 goto failed;
1299 }
1300 s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, flags,
1301 sd.bdev);
1302 mutex_unlock(&sd.bdev->bd_fsfreeze_mutex);
1303 if (IS_ERR(s)) {
1304 err = PTR_ERR(s);
1305 goto failed;
1306 }
1307
1308 if (!s->s_root) {
1309 s_new = true;
1310
1311 /* New superblock instance created */
1312 s->s_mode = mode;
1313 snprintf(s->s_id, sizeof(s->s_id), "%pg", sd.bdev);
1314 sb_set_blocksize(s, block_size(sd.bdev));
1315
1316 err = nilfs_fill_super(s, data, flags & SB_SILENT ? 1 : 0);
1317 if (err)
1318 goto failed_super;
1319
1320 s->s_flags |= SB_ACTIVE;
1321 } else if (!sd.cno) {
1322 if (nilfs_tree_is_busy(s->s_root)) {
1323 if ((flags ^ s->s_flags) & SB_RDONLY) {
1324 nilfs_err(s,
1325 "the device already has a %s mount.",
1326 sb_rdonly(s) ? "read-only" : "read/write");
1327 err = -EBUSY;
1328 goto failed_super;
1329 }
1330 } else {
1331 /*
1332 * Try remount to setup mount states if the current
1333 * tree is not mounted and only snapshots use this sb.
1334 */
1335 err = nilfs_remount(s, &flags, data);
1336 if (err)
1337 goto failed_super;
1338 }
1339 }
1340
1341 if (sd.cno) {
1342 err = nilfs_attach_snapshot(s, sd.cno, &root_dentry);
1343 if (err)
1344 goto failed_super;
1345 } else {
1346 root_dentry = dget(s->s_root);
1347 }
1348
1349 if (!s_new)
1350 blkdev_put(sd.bdev, mode);
1351
1352 return root_dentry;
1353
1354 failed_super:
1355 deactivate_locked_super(s);
1356
1357 failed:
1358 if (!s_new)
1359 blkdev_put(sd.bdev, mode);
1360 return ERR_PTR(err);
1361 }
1362
1363 struct file_system_type nilfs_fs_type = {
1364 .owner = THIS_MODULE,
1365 .name = "nilfs2",
1366 .mount = nilfs_mount,
1367 .kill_sb = kill_block_super,
1368 .fs_flags = FS_REQUIRES_DEV,
1369 };
1370 MODULE_ALIAS_FS("nilfs2");
1371
nilfs_inode_init_once(void * obj)1372 static void nilfs_inode_init_once(void *obj)
1373 {
1374 struct nilfs_inode_info *ii = obj;
1375
1376 INIT_LIST_HEAD(&ii->i_dirty);
1377 #ifdef CONFIG_NILFS_XATTR
1378 init_rwsem(&ii->xattr_sem);
1379 #endif
1380 inode_init_once(&ii->vfs_inode);
1381 }
1382
nilfs_segbuf_init_once(void * obj)1383 static void nilfs_segbuf_init_once(void *obj)
1384 {
1385 memset(obj, 0, sizeof(struct nilfs_segment_buffer));
1386 }
1387
nilfs_destroy_cachep(void)1388 static void nilfs_destroy_cachep(void)
1389 {
1390 /*
1391 * Make sure all delayed rcu free inodes are flushed before we
1392 * destroy cache.
1393 */
1394 rcu_barrier();
1395
1396 kmem_cache_destroy(nilfs_inode_cachep);
1397 kmem_cache_destroy(nilfs_transaction_cachep);
1398 kmem_cache_destroy(nilfs_segbuf_cachep);
1399 kmem_cache_destroy(nilfs_btree_path_cache);
1400 }
1401
nilfs_init_cachep(void)1402 static int __init nilfs_init_cachep(void)
1403 {
1404 nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache",
1405 sizeof(struct nilfs_inode_info), 0,
1406 SLAB_RECLAIM_ACCOUNT|SLAB_ACCOUNT,
1407 nilfs_inode_init_once);
1408 if (!nilfs_inode_cachep)
1409 goto fail;
1410
1411 nilfs_transaction_cachep = kmem_cache_create("nilfs2_transaction_cache",
1412 sizeof(struct nilfs_transaction_info), 0,
1413 SLAB_RECLAIM_ACCOUNT, NULL);
1414 if (!nilfs_transaction_cachep)
1415 goto fail;
1416
1417 nilfs_segbuf_cachep = kmem_cache_create("nilfs2_segbuf_cache",
1418 sizeof(struct nilfs_segment_buffer), 0,
1419 SLAB_RECLAIM_ACCOUNT, nilfs_segbuf_init_once);
1420 if (!nilfs_segbuf_cachep)
1421 goto fail;
1422
1423 nilfs_btree_path_cache = kmem_cache_create("nilfs2_btree_path_cache",
1424 sizeof(struct nilfs_btree_path) * NILFS_BTREE_LEVEL_MAX,
1425 0, 0, NULL);
1426 if (!nilfs_btree_path_cache)
1427 goto fail;
1428
1429 return 0;
1430
1431 fail:
1432 nilfs_destroy_cachep();
1433 return -ENOMEM;
1434 }
1435
init_nilfs_fs(void)1436 static int __init init_nilfs_fs(void)
1437 {
1438 int err;
1439
1440 err = nilfs_init_cachep();
1441 if (err)
1442 goto fail;
1443
1444 err = nilfs_sysfs_init();
1445 if (err)
1446 goto free_cachep;
1447
1448 err = register_filesystem(&nilfs_fs_type);
1449 if (err)
1450 goto deinit_sysfs_entry;
1451
1452 printk(KERN_INFO "NILFS version 2 loaded\n");
1453 return 0;
1454
1455 deinit_sysfs_entry:
1456 nilfs_sysfs_exit();
1457 free_cachep:
1458 nilfs_destroy_cachep();
1459 fail:
1460 return err;
1461 }
1462
exit_nilfs_fs(void)1463 static void __exit exit_nilfs_fs(void)
1464 {
1465 nilfs_destroy_cachep();
1466 nilfs_sysfs_exit();
1467 unregister_filesystem(&nilfs_fs_type);
1468 }
1469
1470 module_init(init_nilfs_fs)
1471 module_exit(exit_nilfs_fs)
1472