nilfs2: fix list corruption after ifile creation failure
[linux-2.6.git] / fs / nilfs2 / super.c
1 /*
2  * super.c - NILFS module and super block management.
3  *
4  * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
19  *
20  * Written by Ryusuke Konishi <ryusuke@osrg.net>
21  */
22 /*
23  *  linux/fs/ext2/super.c
24  *
25  * Copyright (C) 1992, 1993, 1994, 1995
26  * Remy Card (card@masi.ibp.fr)
27  * Laboratoire MASI - Institut Blaise Pascal
28  * Universite Pierre et Marie Curie (Paris VI)
29  *
30  *  from
31  *
32  *  linux/fs/minix/inode.c
33  *
34  *  Copyright (C) 1991, 1992  Linus Torvalds
35  *
36  *  Big-endian to little-endian byte-swapping/bitmaps by
37  *        David S. Miller (davem@caip.rutgers.edu), 1995
38  */
39
40 #include <linux/module.h>
41 #include <linux/string.h>
42 #include <linux/slab.h>
43 #include <linux/init.h>
44 #include <linux/blkdev.h>
45 #include <linux/parser.h>
46 #include <linux/random.h>
47 #include <linux/crc32.h>
48 #include <linux/smp_lock.h>
49 #include <linux/vfs.h>
50 #include <linux/writeback.h>
51 #include <linux/kobject.h>
52 #include <linux/exportfs.h>
53 #include <linux/seq_file.h>
54 #include <linux/mount.h>
55 #include "nilfs.h"
56 #include "mdt.h"
57 #include "alloc.h"
58 #include "btree.h"
59 #include "btnode.h"
60 #include "page.h"
61 #include "cpfile.h"
62 #include "ifile.h"
63 #include "dat.h"
64 #include "segment.h"
65 #include "segbuf.h"
66
67 MODULE_AUTHOR("NTT Corp.");
68 MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem "
69                    "(NILFS)");
70 MODULE_LICENSE("GPL");
71
72 struct kmem_cache *nilfs_inode_cachep;
73 struct kmem_cache *nilfs_transaction_cachep;
74 struct kmem_cache *nilfs_segbuf_cachep;
75 struct kmem_cache *nilfs_btree_path_cache;
76
77 static int nilfs_remount(struct super_block *sb, int *flags, char *data);
78
79 static void nilfs_set_error(struct nilfs_sb_info *sbi)
80 {
81         struct the_nilfs *nilfs = sbi->s_nilfs;
82         struct nilfs_super_block **sbp;
83
84         down_write(&nilfs->ns_sem);
85         if (!(nilfs->ns_mount_state & NILFS_ERROR_FS)) {
86                 nilfs->ns_mount_state |= NILFS_ERROR_FS;
87                 sbp = nilfs_prepare_super(sbi, 0);
88                 if (likely(sbp)) {
89                         sbp[0]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
90                         if (sbp[1])
91                                 sbp[1]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
92                         nilfs_commit_super(sbi, NILFS_SB_COMMIT_ALL);
93                 }
94         }
95         up_write(&nilfs->ns_sem);
96 }
97
98 /**
99  * nilfs_error() - report failure condition on a filesystem
100  *
101  * nilfs_error() sets an ERROR_FS flag on the superblock as well as
102  * reporting an error message.  It should be called when NILFS detects
103  * incoherences or defects of meta data on disk.  As for sustainable
104  * errors such as a single-shot I/O error, nilfs_warning() or the printk()
105  * function should be used instead.
106  *
107  * The segment constructor must not call this function because it can
108  * kill itself.
109  */
110 void nilfs_error(struct super_block *sb, const char *function,
111                  const char *fmt, ...)
112 {
113         struct nilfs_sb_info *sbi = NILFS_SB(sb);
114         va_list args;
115
116         va_start(args, fmt);
117         printk(KERN_CRIT "NILFS error (device %s): %s: ", sb->s_id, function);
118         vprintk(fmt, args);
119         printk("\n");
120         va_end(args);
121
122         if (!(sb->s_flags & MS_RDONLY)) {
123                 nilfs_set_error(sbi);
124
125                 if (nilfs_test_opt(sbi, ERRORS_RO)) {
126                         printk(KERN_CRIT "Remounting filesystem read-only\n");
127                         sb->s_flags |= MS_RDONLY;
128                 }
129         }
130
131         if (nilfs_test_opt(sbi, ERRORS_PANIC))
132                 panic("NILFS (device %s): panic forced after error\n",
133                       sb->s_id);
134 }
135
136 void nilfs_warning(struct super_block *sb, const char *function,
137                    const char *fmt, ...)
138 {
139         va_list args;
140
141         va_start(args, fmt);
142         printk(KERN_WARNING "NILFS warning (device %s): %s: ",
143                sb->s_id, function);
144         vprintk(fmt, args);
145         printk("\n");
146         va_end(args);
147 }
148
149
150 struct inode *nilfs_alloc_inode_common(struct the_nilfs *nilfs)
151 {
152         struct nilfs_inode_info *ii;
153
154         ii = kmem_cache_alloc(nilfs_inode_cachep, GFP_NOFS);
155         if (!ii)
156                 return NULL;
157         ii->i_bh = NULL;
158         ii->i_state = 0;
159         ii->vfs_inode.i_version = 1;
160         nilfs_btnode_cache_init(&ii->i_btnode_cache, nilfs->ns_bdi);
161         return &ii->vfs_inode;
162 }
163
164 struct inode *nilfs_alloc_inode(struct super_block *sb)
165 {
166         return nilfs_alloc_inode_common(NILFS_SB(sb)->s_nilfs);
167 }
168
169 void nilfs_destroy_inode(struct inode *inode)
170 {
171         kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode));
172 }
173
174 static int nilfs_sync_super(struct nilfs_sb_info *sbi, int flag)
175 {
176         struct the_nilfs *nilfs = sbi->s_nilfs;
177         int err;
178         int barrier_done = 0;
179
180         if (nilfs_test_opt(sbi, BARRIER)) {
181                 set_buffer_ordered(nilfs->ns_sbh[0]);
182                 barrier_done = 1;
183         }
184  retry:
185         set_buffer_dirty(nilfs->ns_sbh[0]);
186         err = sync_dirty_buffer(nilfs->ns_sbh[0]);
187         if (err == -EOPNOTSUPP && barrier_done) {
188                 nilfs_warning(sbi->s_super, __func__,
189                               "barrier-based sync failed. "
190                               "disabling barriers\n");
191                 nilfs_clear_opt(sbi, BARRIER);
192                 barrier_done = 0;
193                 clear_buffer_ordered(nilfs->ns_sbh[0]);
194                 goto retry;
195         }
196         if (unlikely(err)) {
197                 printk(KERN_ERR
198                        "NILFS: unable to write superblock (err=%d)\n", err);
199                 if (err == -EIO && nilfs->ns_sbh[1]) {
200                         /*
201                          * sbp[0] points to newer log than sbp[1],
202                          * so copy sbp[0] to sbp[1] to take over sbp[0].
203                          */
204                         memcpy(nilfs->ns_sbp[1], nilfs->ns_sbp[0],
205                                nilfs->ns_sbsize);
206                         nilfs_fall_back_super_block(nilfs);
207                         goto retry;
208                 }
209         } else {
210                 struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
211
212                 nilfs->ns_sbwcount++;
213
214                 /*
215                  * The latest segment becomes trailable from the position
216                  * written in superblock.
217                  */
218                 clear_nilfs_discontinued(nilfs);
219
220                 /* update GC protection for recent segments */
221                 if (nilfs->ns_sbh[1]) {
222                         if (flag == NILFS_SB_COMMIT_ALL) {
223                                 set_buffer_dirty(nilfs->ns_sbh[1]);
224                                 if (sync_dirty_buffer(nilfs->ns_sbh[1]) < 0)
225                                         goto out;
226                         }
227                         if (le64_to_cpu(nilfs->ns_sbp[1]->s_last_cno) <
228                             le64_to_cpu(nilfs->ns_sbp[0]->s_last_cno))
229                                 sbp = nilfs->ns_sbp[1];
230                 }
231
232                 spin_lock(&nilfs->ns_last_segment_lock);
233                 nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq);
234                 spin_unlock(&nilfs->ns_last_segment_lock);
235         }
236  out:
237         return err;
238 }
239
240 void nilfs_set_log_cursor(struct nilfs_super_block *sbp,
241                           struct the_nilfs *nilfs)
242 {
243         sector_t nfreeblocks;
244
245         /* nilfs->ns_sem must be locked by the caller. */
246         nilfs_count_free_blocks(nilfs, &nfreeblocks);
247         sbp->s_free_blocks_count = cpu_to_le64(nfreeblocks);
248
249         spin_lock(&nilfs->ns_last_segment_lock);
250         sbp->s_last_seq = cpu_to_le64(nilfs->ns_last_seq);
251         sbp->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg);
252         sbp->s_last_cno = cpu_to_le64(nilfs->ns_last_cno);
253         spin_unlock(&nilfs->ns_last_segment_lock);
254 }
255
256 struct nilfs_super_block **nilfs_prepare_super(struct nilfs_sb_info *sbi,
257                                                int flip)
258 {
259         struct the_nilfs *nilfs = sbi->s_nilfs;
260         struct nilfs_super_block **sbp = nilfs->ns_sbp;
261
262         /* nilfs->ns_sem must be locked by the caller. */
263         if (sbp[0]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
264                 if (sbp[1] &&
265                     sbp[1]->s_magic == cpu_to_le16(NILFS_SUPER_MAGIC)) {
266                         memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
267                 } else {
268                         printk(KERN_CRIT "NILFS: superblock broke on dev %s\n",
269                                sbi->s_super->s_id);
270                         return NULL;
271                 }
272         } else if (sbp[1] &&
273                    sbp[1]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
274                         memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
275         }
276
277         if (flip && sbp[1])
278                 nilfs_swap_super_block(nilfs);
279
280         return sbp;
281 }
282
283 int nilfs_commit_super(struct nilfs_sb_info *sbi, int flag)
284 {
285         struct the_nilfs *nilfs = sbi->s_nilfs;
286         struct nilfs_super_block **sbp = nilfs->ns_sbp;
287         time_t t;
288
289         /* nilfs->ns_sem must be locked by the caller. */
290         t = get_seconds();
291         nilfs->ns_sbwtime = t;
292         sbp[0]->s_wtime = cpu_to_le64(t);
293         sbp[0]->s_sum = 0;
294         sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
295                                              (unsigned char *)sbp[0],
296                                              nilfs->ns_sbsize));
297         if (flag == NILFS_SB_COMMIT_ALL && sbp[1]) {
298                 sbp[1]->s_wtime = sbp[0]->s_wtime;
299                 sbp[1]->s_sum = 0;
300                 sbp[1]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
301                                             (unsigned char *)sbp[1],
302                                             nilfs->ns_sbsize));
303         }
304         clear_nilfs_sb_dirty(nilfs);
305         return nilfs_sync_super(sbi, flag);
306 }
307
308 /**
309  * nilfs_cleanup_super() - write filesystem state for cleanup
310  * @sbi: nilfs_sb_info to be unmounted or degraded to read-only
311  *
312  * This function restores state flags in the on-disk super block.
313  * This will set "clean" flag (i.e. NILFS_VALID_FS) unless the
314  * filesystem was not clean previously.
315  */
316 int nilfs_cleanup_super(struct nilfs_sb_info *sbi)
317 {
318         struct nilfs_super_block **sbp;
319         int flag = NILFS_SB_COMMIT;
320         int ret = -EIO;
321
322         sbp = nilfs_prepare_super(sbi, 0);
323         if (sbp) {
324                 sbp[0]->s_state = cpu_to_le16(sbi->s_nilfs->ns_mount_state);
325                 nilfs_set_log_cursor(sbp[0], sbi->s_nilfs);
326                 if (sbp[1] && sbp[0]->s_last_cno == sbp[1]->s_last_cno) {
327                         /*
328                          * make the "clean" flag also to the opposite
329                          * super block if both super blocks point to
330                          * the same checkpoint.
331                          */
332                         sbp[1]->s_state = sbp[0]->s_state;
333                         flag = NILFS_SB_COMMIT_ALL;
334                 }
335                 ret = nilfs_commit_super(sbi, flag);
336         }
337         return ret;
338 }
339
340 static void nilfs_put_super(struct super_block *sb)
341 {
342         struct nilfs_sb_info *sbi = NILFS_SB(sb);
343         struct the_nilfs *nilfs = sbi->s_nilfs;
344
345         lock_kernel();
346
347         nilfs_detach_segment_constructor(sbi);
348
349         if (!(sb->s_flags & MS_RDONLY)) {
350                 down_write(&nilfs->ns_sem);
351                 nilfs_cleanup_super(sbi);
352                 up_write(&nilfs->ns_sem);
353         }
354         down_write(&nilfs->ns_super_sem);
355         if (nilfs->ns_current == sbi)
356                 nilfs->ns_current = NULL;
357         up_write(&nilfs->ns_super_sem);
358
359         nilfs_detach_checkpoint(sbi);
360         put_nilfs(sbi->s_nilfs);
361         sbi->s_super = NULL;
362         sb->s_fs_info = NULL;
363         nilfs_put_sbinfo(sbi);
364
365         unlock_kernel();
366 }
367
368 static int nilfs_sync_fs(struct super_block *sb, int wait)
369 {
370         struct nilfs_sb_info *sbi = NILFS_SB(sb);
371         struct the_nilfs *nilfs = sbi->s_nilfs;
372         struct nilfs_super_block **sbp;
373         int err = 0;
374
375         /* This function is called when super block should be written back */
376         if (wait)
377                 err = nilfs_construct_segment(sb);
378
379         down_write(&nilfs->ns_sem);
380         if (nilfs_sb_dirty(nilfs)) {
381                 sbp = nilfs_prepare_super(sbi, nilfs_sb_will_flip(nilfs));
382                 if (likely(sbp)) {
383                         nilfs_set_log_cursor(sbp[0], nilfs);
384                         nilfs_commit_super(sbi, NILFS_SB_COMMIT);
385                 }
386         }
387         up_write(&nilfs->ns_sem);
388
389         return err;
390 }
391
392 int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno)
393 {
394         struct the_nilfs *nilfs = sbi->s_nilfs;
395         struct nilfs_checkpoint *raw_cp;
396         struct buffer_head *bh_cp;
397         int err;
398
399         down_write(&nilfs->ns_super_sem);
400         list_add(&sbi->s_list, &nilfs->ns_supers);
401         up_write(&nilfs->ns_super_sem);
402
403         err = -ENOMEM;
404         sbi->s_ifile = nilfs_ifile_new(sbi, nilfs->ns_inode_size);
405         if (!sbi->s_ifile)
406                 goto delist;
407
408         down_read(&nilfs->ns_segctor_sem);
409         err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp,
410                                           &bh_cp);
411         up_read(&nilfs->ns_segctor_sem);
412         if (unlikely(err)) {
413                 if (err == -ENOENT || err == -EINVAL) {
414                         printk(KERN_ERR
415                                "NILFS: Invalid checkpoint "
416                                "(checkpoint number=%llu)\n",
417                                (unsigned long long)cno);
418                         err = -EINVAL;
419                 }
420                 goto failed;
421         }
422         err = nilfs_read_inode_common(sbi->s_ifile, &raw_cp->cp_ifile_inode);
423         if (unlikely(err))
424                 goto failed_bh;
425         atomic_set(&sbi->s_inodes_count, le64_to_cpu(raw_cp->cp_inodes_count));
426         atomic_set(&sbi->s_blocks_count, le64_to_cpu(raw_cp->cp_blocks_count));
427
428         nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
429         return 0;
430
431  failed_bh:
432         nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
433  failed:
434         nilfs_mdt_destroy(sbi->s_ifile);
435         sbi->s_ifile = NULL;
436
437  delist:
438         down_write(&nilfs->ns_super_sem);
439         list_del_init(&sbi->s_list);
440         up_write(&nilfs->ns_super_sem);
441
442         return err;
443 }
444
445 void nilfs_detach_checkpoint(struct nilfs_sb_info *sbi)
446 {
447         struct the_nilfs *nilfs = sbi->s_nilfs;
448
449         nilfs_mdt_destroy(sbi->s_ifile);
450         sbi->s_ifile = NULL;
451         down_write(&nilfs->ns_super_sem);
452         list_del_init(&sbi->s_list);
453         up_write(&nilfs->ns_super_sem);
454 }
455
456 static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
457 {
458         struct super_block *sb = dentry->d_sb;
459         struct nilfs_sb_info *sbi = NILFS_SB(sb);
460         struct the_nilfs *nilfs = sbi->s_nilfs;
461         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
462         unsigned long long blocks;
463         unsigned long overhead;
464         unsigned long nrsvblocks;
465         sector_t nfreeblocks;
466         int err;
467
468         /*
469          * Compute all of the segment blocks
470          *
471          * The blocks before first segment and after last segment
472          * are excluded.
473          */
474         blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments
475                 - nilfs->ns_first_data_block;
476         nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment;
477
478         /*
479          * Compute the overhead
480          *
481          * When distributing meta data blocks outside segment structure,
482          * We must count them as the overhead.
483          */
484         overhead = 0;
485
486         err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
487         if (unlikely(err))
488                 return err;
489
490         buf->f_type = NILFS_SUPER_MAGIC;
491         buf->f_bsize = sb->s_blocksize;
492         buf->f_blocks = blocks - overhead;
493         buf->f_bfree = nfreeblocks;
494         buf->f_bavail = (buf->f_bfree >= nrsvblocks) ?
495                 (buf->f_bfree - nrsvblocks) : 0;
496         buf->f_files = atomic_read(&sbi->s_inodes_count);
497         buf->f_ffree = 0; /* nilfs_count_free_inodes(sb); */
498         buf->f_namelen = NILFS_NAME_LEN;
499         buf->f_fsid.val[0] = (u32)id;
500         buf->f_fsid.val[1] = (u32)(id >> 32);
501
502         return 0;
503 }
504
505 static int nilfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
506 {
507         struct super_block *sb = vfs->mnt_sb;
508         struct nilfs_sb_info *sbi = NILFS_SB(sb);
509
510         if (!nilfs_test_opt(sbi, BARRIER))
511                 seq_puts(seq, ",nobarrier");
512         if (nilfs_test_opt(sbi, SNAPSHOT))
513                 seq_printf(seq, ",cp=%llu",
514                            (unsigned long long int)sbi->s_snapshot_cno);
515         if (nilfs_test_opt(sbi, ERRORS_PANIC))
516                 seq_puts(seq, ",errors=panic");
517         if (nilfs_test_opt(sbi, ERRORS_CONT))
518                 seq_puts(seq, ",errors=continue");
519         if (nilfs_test_opt(sbi, STRICT_ORDER))
520                 seq_puts(seq, ",order=strict");
521         if (nilfs_test_opt(sbi, NORECOVERY))
522                 seq_puts(seq, ",norecovery");
523         if (nilfs_test_opt(sbi, DISCARD))
524                 seq_puts(seq, ",discard");
525
526         return 0;
527 }
528
529 static const struct super_operations nilfs_sops = {
530         .alloc_inode    = nilfs_alloc_inode,
531         .destroy_inode  = nilfs_destroy_inode,
532         .dirty_inode    = nilfs_dirty_inode,
533         /* .write_inode    = nilfs_write_inode, */
534         /* .put_inode      = nilfs_put_inode, */
535         /* .drop_inode    = nilfs_drop_inode, */
536         .evict_inode    = nilfs_evict_inode,
537         .put_super      = nilfs_put_super,
538         /* .write_super    = nilfs_write_super, */
539         .sync_fs        = nilfs_sync_fs,
540         /* .write_super_lockfs */
541         /* .unlockfs */
542         .statfs         = nilfs_statfs,
543         .remount_fs     = nilfs_remount,
544         /* .umount_begin */
545         .show_options = nilfs_show_options
546 };
547
548 static struct inode *
549 nilfs_nfs_get_inode(struct super_block *sb, u64 ino, u32 generation)
550 {
551         struct inode *inode;
552
553         if (ino < NILFS_FIRST_INO(sb) && ino != NILFS_ROOT_INO &&
554             ino != NILFS_SKETCH_INO)
555                 return ERR_PTR(-ESTALE);
556
557         inode = nilfs_iget(sb, ino);
558         if (IS_ERR(inode))
559                 return ERR_CAST(inode);
560         if (generation && inode->i_generation != generation) {
561                 iput(inode);
562                 return ERR_PTR(-ESTALE);
563         }
564
565         return inode;
566 }
567
568 static struct dentry *
569 nilfs_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len,
570                    int fh_type)
571 {
572         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
573                                     nilfs_nfs_get_inode);
574 }
575
576 static struct dentry *
577 nilfs_fh_to_parent(struct super_block *sb, struct fid *fid, int fh_len,
578                    int fh_type)
579 {
580         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
581                                     nilfs_nfs_get_inode);
582 }
583
584 static const struct export_operations nilfs_export_ops = {
585         .fh_to_dentry = nilfs_fh_to_dentry,
586         .fh_to_parent = nilfs_fh_to_parent,
587         .get_parent = nilfs_get_parent,
588 };
589
590 enum {
591         Opt_err_cont, Opt_err_panic, Opt_err_ro,
592         Opt_barrier, Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery,
593         Opt_discard, Opt_nodiscard, Opt_err,
594 };
595
596 static match_table_t tokens = {
597         {Opt_err_cont, "errors=continue"},
598         {Opt_err_panic, "errors=panic"},
599         {Opt_err_ro, "errors=remount-ro"},
600         {Opt_barrier, "barrier"},
601         {Opt_nobarrier, "nobarrier"},
602         {Opt_snapshot, "cp=%u"},
603         {Opt_order, "order=%s"},
604         {Opt_norecovery, "norecovery"},
605         {Opt_discard, "discard"},
606         {Opt_nodiscard, "nodiscard"},
607         {Opt_err, NULL}
608 };
609
610 static int parse_options(char *options, struct super_block *sb, int is_remount)
611 {
612         struct nilfs_sb_info *sbi = NILFS_SB(sb);
613         char *p;
614         substring_t args[MAX_OPT_ARGS];
615         int option;
616
617         if (!options)
618                 return 1;
619
620         while ((p = strsep(&options, ",")) != NULL) {
621                 int token;
622                 if (!*p)
623                         continue;
624
625                 token = match_token(p, tokens, args);
626                 switch (token) {
627                 case Opt_barrier:
628                         nilfs_set_opt(sbi, BARRIER);
629                         break;
630                 case Opt_nobarrier:
631                         nilfs_clear_opt(sbi, BARRIER);
632                         break;
633                 case Opt_order:
634                         if (strcmp(args[0].from, "relaxed") == 0)
635                                 /* Ordered data semantics */
636                                 nilfs_clear_opt(sbi, STRICT_ORDER);
637                         else if (strcmp(args[0].from, "strict") == 0)
638                                 /* Strict in-order semantics */
639                                 nilfs_set_opt(sbi, STRICT_ORDER);
640                         else
641                                 return 0;
642                         break;
643                 case Opt_err_panic:
644                         nilfs_write_opt(sbi, ERROR_MODE, ERRORS_PANIC);
645                         break;
646                 case Opt_err_ro:
647                         nilfs_write_opt(sbi, ERROR_MODE, ERRORS_RO);
648                         break;
649                 case Opt_err_cont:
650                         nilfs_write_opt(sbi, ERROR_MODE, ERRORS_CONT);
651                         break;
652                 case Opt_snapshot:
653                         if (match_int(&args[0], &option) || option <= 0)
654                                 return 0;
655                         if (is_remount) {
656                                 if (!nilfs_test_opt(sbi, SNAPSHOT)) {
657                                         printk(KERN_ERR
658                                                "NILFS: cannot change regular "
659                                                "mount to snapshot.\n");
660                                         return 0;
661                                 } else if (option != sbi->s_snapshot_cno) {
662                                         printk(KERN_ERR
663                                                "NILFS: cannot remount to a "
664                                                "different snapshot.\n");
665                                         return 0;
666                                 }
667                                 break;
668                         }
669                         if (!(sb->s_flags & MS_RDONLY)) {
670                                 printk(KERN_ERR "NILFS: cannot mount snapshot "
671                                        "read/write.  A read-only option is "
672                                        "required.\n");
673                                 return 0;
674                         }
675                         sbi->s_snapshot_cno = option;
676                         nilfs_set_opt(sbi, SNAPSHOT);
677                         break;
678                 case Opt_norecovery:
679                         nilfs_set_opt(sbi, NORECOVERY);
680                         break;
681                 case Opt_discard:
682                         nilfs_set_opt(sbi, DISCARD);
683                         break;
684                 case Opt_nodiscard:
685                         nilfs_clear_opt(sbi, DISCARD);
686                         break;
687                 default:
688                         printk(KERN_ERR
689                                "NILFS: Unrecognized mount option \"%s\"\n", p);
690                         return 0;
691                 }
692         }
693         return 1;
694 }
695
696 static inline void
697 nilfs_set_default_options(struct nilfs_sb_info *sbi,
698                           struct nilfs_super_block *sbp)
699 {
700         sbi->s_mount_opt =
701                 NILFS_MOUNT_ERRORS_RO | NILFS_MOUNT_BARRIER;
702 }
703
704 static int nilfs_setup_super(struct nilfs_sb_info *sbi)
705 {
706         struct the_nilfs *nilfs = sbi->s_nilfs;
707         struct nilfs_super_block **sbp;
708         int max_mnt_count;
709         int mnt_count;
710
711         /* nilfs->ns_sem must be locked by the caller. */
712         sbp = nilfs_prepare_super(sbi, 0);
713         if (!sbp)
714                 return -EIO;
715
716         max_mnt_count = le16_to_cpu(sbp[0]->s_max_mnt_count);
717         mnt_count = le16_to_cpu(sbp[0]->s_mnt_count);
718
719         if (nilfs->ns_mount_state & NILFS_ERROR_FS) {
720                 printk(KERN_WARNING
721                        "NILFS warning: mounting fs with errors\n");
722 #if 0
723         } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) {
724                 printk(KERN_WARNING
725                        "NILFS warning: maximal mount count reached\n");
726 #endif
727         }
728         if (!max_mnt_count)
729                 sbp[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT);
730
731         sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1);
732         sbp[0]->s_state =
733                 cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS);
734         sbp[0]->s_mtime = cpu_to_le64(get_seconds());
735         /* synchronize sbp[1] with sbp[0] */
736         memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
737         return nilfs_commit_super(sbi, NILFS_SB_COMMIT_ALL);
738 }
739
740 struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb,
741                                                  u64 pos, int blocksize,
742                                                  struct buffer_head **pbh)
743 {
744         unsigned long long sb_index = pos;
745         unsigned long offset;
746
747         offset = do_div(sb_index, blocksize);
748         *pbh = sb_bread(sb, sb_index);
749         if (!*pbh)
750                 return NULL;
751         return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset);
752 }
753
754 int nilfs_store_magic_and_option(struct super_block *sb,
755                                  struct nilfs_super_block *sbp,
756                                  char *data)
757 {
758         struct nilfs_sb_info *sbi = NILFS_SB(sb);
759
760         sb->s_magic = le16_to_cpu(sbp->s_magic);
761
762         /* FS independent flags */
763 #ifdef NILFS_ATIME_DISABLE
764         sb->s_flags |= MS_NOATIME;
765 #endif
766
767         nilfs_set_default_options(sbi, sbp);
768
769         sbi->s_resuid = le16_to_cpu(sbp->s_def_resuid);
770         sbi->s_resgid = le16_to_cpu(sbp->s_def_resgid);
771         sbi->s_interval = le32_to_cpu(sbp->s_c_interval);
772         sbi->s_watermark = le32_to_cpu(sbp->s_c_block_max);
773
774         return !parse_options(data, sb, 0) ? -EINVAL : 0 ;
775 }
776
777 int nilfs_check_feature_compatibility(struct super_block *sb,
778                                       struct nilfs_super_block *sbp)
779 {
780         __u64 features;
781
782         features = le64_to_cpu(sbp->s_feature_incompat) &
783                 ~NILFS_FEATURE_INCOMPAT_SUPP;
784         if (features) {
785                 printk(KERN_ERR "NILFS: couldn't mount because of unsupported "
786                        "optional features (%llx)\n",
787                        (unsigned long long)features);
788                 return -EINVAL;
789         }
790         features = le64_to_cpu(sbp->s_feature_compat_ro) &
791                 ~NILFS_FEATURE_COMPAT_RO_SUPP;
792         if (!(sb->s_flags & MS_RDONLY) && features) {
793                 printk(KERN_ERR "NILFS: couldn't mount RDWR because of "
794                        "unsupported optional features (%llx)\n",
795                        (unsigned long long)features);
796                 return -EINVAL;
797         }
798         return 0;
799 }
800
801 /**
802  * nilfs_fill_super() - initialize a super block instance
803  * @sb: super_block
804  * @data: mount options
805  * @silent: silent mode flag
806  * @nilfs: the_nilfs struct
807  *
808  * This function is called exclusively by nilfs->ns_mount_mutex.
809  * So, the recovery process is protected from other simultaneous mounts.
810  */
811 static int
812 nilfs_fill_super(struct super_block *sb, void *data, int silent,
813                  struct the_nilfs *nilfs)
814 {
815         struct nilfs_sb_info *sbi;
816         struct inode *root;
817         __u64 cno;
818         int err;
819
820         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
821         if (!sbi)
822                 return -ENOMEM;
823
824         sb->s_fs_info = sbi;
825
826         get_nilfs(nilfs);
827         sbi->s_nilfs = nilfs;
828         sbi->s_super = sb;
829         atomic_set(&sbi->s_count, 1);
830
831         err = init_nilfs(nilfs, sbi, (char *)data);
832         if (err)
833                 goto failed_sbi;
834
835         spin_lock_init(&sbi->s_inode_lock);
836         INIT_LIST_HEAD(&sbi->s_dirty_files);
837         INIT_LIST_HEAD(&sbi->s_list);
838
839         /*
840          * Following initialization is overlapped because
841          * nilfs_sb_info structure has been cleared at the beginning.
842          * But we reserve them to keep our interest and make ready
843          * for the future change.
844          */
845         get_random_bytes(&sbi->s_next_generation,
846                          sizeof(sbi->s_next_generation));
847         spin_lock_init(&sbi->s_next_gen_lock);
848
849         sb->s_op = &nilfs_sops;
850         sb->s_export_op = &nilfs_export_ops;
851         sb->s_root = NULL;
852         sb->s_time_gran = 1;
853         sb->s_bdi = nilfs->ns_bdi;
854
855         err = load_nilfs(nilfs, sbi);
856         if (err)
857                 goto failed_sbi;
858
859         cno = nilfs_last_cno(nilfs);
860
861         if (sb->s_flags & MS_RDONLY) {
862                 if (nilfs_test_opt(sbi, SNAPSHOT)) {
863                         down_read(&nilfs->ns_segctor_sem);
864                         err = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile,
865                                                        sbi->s_snapshot_cno);
866                         up_read(&nilfs->ns_segctor_sem);
867                         if (err < 0) {
868                                 if (err == -ENOENT)
869                                         err = -EINVAL;
870                                 goto failed_sbi;
871                         }
872                         if (!err) {
873                                 printk(KERN_ERR
874                                        "NILFS: The specified checkpoint is "
875                                        "not a snapshot "
876                                        "(checkpoint number=%llu).\n",
877                                        (unsigned long long)sbi->s_snapshot_cno);
878                                 err = -EINVAL;
879                                 goto failed_sbi;
880                         }
881                         cno = sbi->s_snapshot_cno;
882                 }
883         }
884
885         err = nilfs_attach_checkpoint(sbi, cno);
886         if (err) {
887                 printk(KERN_ERR "NILFS: error loading a checkpoint"
888                        " (checkpoint number=%llu).\n", (unsigned long long)cno);
889                 goto failed_sbi;
890         }
891
892         if (!(sb->s_flags & MS_RDONLY)) {
893                 err = nilfs_attach_segment_constructor(sbi);
894                 if (err)
895                         goto failed_checkpoint;
896         }
897
898         root = nilfs_iget(sb, NILFS_ROOT_INO);
899         if (IS_ERR(root)) {
900                 printk(KERN_ERR "NILFS: get root inode failed\n");
901                 err = PTR_ERR(root);
902                 goto failed_segctor;
903         }
904         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
905                 iput(root);
906                 printk(KERN_ERR "NILFS: corrupt root inode.\n");
907                 err = -EINVAL;
908                 goto failed_segctor;
909         }
910         sb->s_root = d_alloc_root(root);
911         if (!sb->s_root) {
912                 iput(root);
913                 printk(KERN_ERR "NILFS: get root dentry failed\n");
914                 err = -ENOMEM;
915                 goto failed_segctor;
916         }
917
918         if (!(sb->s_flags & MS_RDONLY)) {
919                 down_write(&nilfs->ns_sem);
920                 nilfs_setup_super(sbi);
921                 up_write(&nilfs->ns_sem);
922         }
923
924         down_write(&nilfs->ns_super_sem);
925         if (!nilfs_test_opt(sbi, SNAPSHOT))
926                 nilfs->ns_current = sbi;
927         up_write(&nilfs->ns_super_sem);
928
929         return 0;
930
931  failed_segctor:
932         nilfs_detach_segment_constructor(sbi);
933
934  failed_checkpoint:
935         nilfs_detach_checkpoint(sbi);
936
937  failed_sbi:
938         put_nilfs(nilfs);
939         sb->s_fs_info = NULL;
940         nilfs_put_sbinfo(sbi);
941         return err;
942 }
943
944 static int nilfs_remount(struct super_block *sb, int *flags, char *data)
945 {
946         struct nilfs_sb_info *sbi = NILFS_SB(sb);
947         struct the_nilfs *nilfs = sbi->s_nilfs;
948         unsigned long old_sb_flags;
949         struct nilfs_mount_options old_opts;
950         int was_snapshot, err;
951
952         lock_kernel();
953
954         down_write(&nilfs->ns_super_sem);
955         old_sb_flags = sb->s_flags;
956         old_opts.mount_opt = sbi->s_mount_opt;
957         old_opts.snapshot_cno = sbi->s_snapshot_cno;
958         was_snapshot = nilfs_test_opt(sbi, SNAPSHOT);
959
960         if (!parse_options(data, sb, 1)) {
961                 err = -EINVAL;
962                 goto restore_opts;
963         }
964         sb->s_flags = (sb->s_flags & ~MS_POSIXACL);
965
966         err = -EINVAL;
967         if (was_snapshot && !(*flags & MS_RDONLY)) {
968                 printk(KERN_ERR "NILFS (device %s): cannot remount snapshot "
969                        "read/write.\n", sb->s_id);
970                 goto restore_opts;
971         }
972
973         if (!nilfs_valid_fs(nilfs)) {
974                 printk(KERN_WARNING "NILFS (device %s): couldn't "
975                        "remount because the filesystem is in an "
976                        "incomplete recovery state.\n", sb->s_id);
977                 goto restore_opts;
978         }
979
980         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
981                 goto out;
982         if (*flags & MS_RDONLY) {
983                 /* Shutting down the segment constructor */
984                 nilfs_detach_segment_constructor(sbi);
985                 sb->s_flags |= MS_RDONLY;
986
987                 /*
988                  * Remounting a valid RW partition RDONLY, so set
989                  * the RDONLY flag and then mark the partition as valid again.
990                  */
991                 down_write(&nilfs->ns_sem);
992                 nilfs_cleanup_super(sbi);
993                 up_write(&nilfs->ns_sem);
994         } else {
995                 __u64 features;
996
997                 /*
998                  * Mounting a RDONLY partition read-write, so reread and
999                  * store the current valid flag.  (It may have been changed
1000                  * by fsck since we originally mounted the partition.)
1001                  */
1002                 down_read(&nilfs->ns_sem);
1003                 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
1004                         ~NILFS_FEATURE_COMPAT_RO_SUPP;
1005                 up_read(&nilfs->ns_sem);
1006                 if (features) {
1007                         printk(KERN_WARNING "NILFS (device %s): couldn't "
1008                                "remount RDWR because of unsupported optional "
1009                                "features (%llx)\n",
1010                                sb->s_id, (unsigned long long)features);
1011                         err = -EROFS;
1012                         goto restore_opts;
1013                 }
1014
1015                 sb->s_flags &= ~MS_RDONLY;
1016
1017                 err = nilfs_attach_segment_constructor(sbi);
1018                 if (err)
1019                         goto restore_opts;
1020
1021                 down_write(&nilfs->ns_sem);
1022                 nilfs_setup_super(sbi);
1023                 up_write(&nilfs->ns_sem);
1024         }
1025  out:
1026         up_write(&nilfs->ns_super_sem);
1027         unlock_kernel();
1028         return 0;
1029
1030  restore_opts:
1031         sb->s_flags = old_sb_flags;
1032         sbi->s_mount_opt = old_opts.mount_opt;
1033         sbi->s_snapshot_cno = old_opts.snapshot_cno;
1034         up_write(&nilfs->ns_super_sem);
1035         unlock_kernel();
1036         return err;
1037 }
1038
1039 struct nilfs_super_data {
1040         struct block_device *bdev;
1041         struct nilfs_sb_info *sbi;
1042         __u64 cno;
1043         int flags;
1044 };
1045
1046 /**
1047  * nilfs_identify - pre-read mount options needed to identify mount instance
1048  * @data: mount options
1049  * @sd: nilfs_super_data
1050  */
1051 static int nilfs_identify(char *data, struct nilfs_super_data *sd)
1052 {
1053         char *p, *options = data;
1054         substring_t args[MAX_OPT_ARGS];
1055         int option, token;
1056         int ret = 0;
1057
1058         do {
1059                 p = strsep(&options, ",");
1060                 if (p != NULL && *p) {
1061                         token = match_token(p, tokens, args);
1062                         if (token == Opt_snapshot) {
1063                                 if (!(sd->flags & MS_RDONLY))
1064                                         ret++;
1065                                 else {
1066                                         ret = match_int(&args[0], &option);
1067                                         if (!ret) {
1068                                                 if (option > 0)
1069                                                         sd->cno = option;
1070                                                 else
1071                                                         ret++;
1072                                         }
1073                                 }
1074                         }
1075                         if (ret)
1076                                 printk(KERN_ERR
1077                                        "NILFS: invalid mount option: %s\n", p);
1078                 }
1079                 if (!options)
1080                         break;
1081                 BUG_ON(options == data);
1082                 *(options - 1) = ',';
1083         } while (!ret);
1084         return ret;
1085 }
1086
1087 static int nilfs_set_bdev_super(struct super_block *s, void *data)
1088 {
1089         struct nilfs_super_data *sd = data;
1090
1091         s->s_bdev = sd->bdev;
1092         s->s_dev = s->s_bdev->bd_dev;
1093         return 0;
1094 }
1095
1096 static int nilfs_test_bdev_super(struct super_block *s, void *data)
1097 {
1098         struct nilfs_super_data *sd = data;
1099
1100         return sd->sbi && s->s_fs_info == (void *)sd->sbi;
1101 }
1102
1103 static int
1104 nilfs_get_sb(struct file_system_type *fs_type, int flags,
1105              const char *dev_name, void *data, struct vfsmount *mnt)
1106 {
1107         struct nilfs_super_data sd;
1108         struct super_block *s;
1109         fmode_t mode = FMODE_READ;
1110         struct the_nilfs *nilfs;
1111         int err, need_to_close = 1;
1112
1113         if (!(flags & MS_RDONLY))
1114                 mode |= FMODE_WRITE;
1115
1116         sd.bdev = open_bdev_exclusive(dev_name, mode, fs_type);
1117         if (IS_ERR(sd.bdev))
1118                 return PTR_ERR(sd.bdev);
1119
1120         /*
1121          * To get mount instance using sget() vfs-routine, NILFS needs
1122          * much more information than normal filesystems to identify mount
1123          * instance.  For snapshot mounts, not only a mount type (ro-mount
1124          * or rw-mount) but also a checkpoint number is required.
1125          */
1126         sd.cno = 0;
1127         sd.flags = flags;
1128         if (nilfs_identify((char *)data, &sd)) {
1129                 err = -EINVAL;
1130                 goto failed;
1131         }
1132
1133         nilfs = find_or_create_nilfs(sd.bdev);
1134         if (!nilfs) {
1135                 err = -ENOMEM;
1136                 goto failed;
1137         }
1138
1139         mutex_lock(&nilfs->ns_mount_mutex);
1140
1141         if (!sd.cno) {
1142                 /*
1143                  * Check if an exclusive mount exists or not.
1144                  * Snapshot mounts coexist with a current mount
1145                  * (i.e. rw-mount or ro-mount), whereas rw-mount and
1146                  * ro-mount are mutually exclusive.
1147                  */
1148                 down_read(&nilfs->ns_super_sem);
1149                 if (nilfs->ns_current &&
1150                     ((nilfs->ns_current->s_super->s_flags ^ flags)
1151                      & MS_RDONLY)) {
1152                         up_read(&nilfs->ns_super_sem);
1153                         err = -EBUSY;
1154                         goto failed_unlock;
1155                 }
1156                 up_read(&nilfs->ns_super_sem);
1157         }
1158
1159         /*
1160          * Find existing nilfs_sb_info struct
1161          */
1162         sd.sbi = nilfs_find_sbinfo(nilfs, !(flags & MS_RDONLY), sd.cno);
1163
1164         /*
1165          * Get super block instance holding the nilfs_sb_info struct.
1166          * A new instance is allocated if no existing mount is present or
1167          * existing instance has been unmounted.
1168          */
1169         s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, &sd);
1170         if (sd.sbi)
1171                 nilfs_put_sbinfo(sd.sbi);
1172
1173         if (IS_ERR(s)) {
1174                 err = PTR_ERR(s);
1175                 goto failed_unlock;
1176         }
1177
1178         if (!s->s_root) {
1179                 char b[BDEVNAME_SIZE];
1180
1181                 /* New superblock instance created */
1182                 s->s_flags = flags;
1183                 s->s_mode = mode;
1184                 strlcpy(s->s_id, bdevname(sd.bdev, b), sizeof(s->s_id));
1185                 sb_set_blocksize(s, block_size(sd.bdev));
1186
1187                 err = nilfs_fill_super(s, data, flags & MS_SILENT ? 1 : 0,
1188                                        nilfs);
1189                 if (err)
1190                         goto cancel_new;
1191
1192                 s->s_flags |= MS_ACTIVE;
1193                 need_to_close = 0;
1194         }
1195
1196         mutex_unlock(&nilfs->ns_mount_mutex);
1197         put_nilfs(nilfs);
1198         if (need_to_close)
1199                 close_bdev_exclusive(sd.bdev, mode);
1200         simple_set_mnt(mnt, s);
1201         return 0;
1202
1203  failed_unlock:
1204         mutex_unlock(&nilfs->ns_mount_mutex);
1205         put_nilfs(nilfs);
1206  failed:
1207         close_bdev_exclusive(sd.bdev, mode);
1208
1209         return err;
1210
1211  cancel_new:
1212         /* Abandoning the newly allocated superblock */
1213         mutex_unlock(&nilfs->ns_mount_mutex);
1214         put_nilfs(nilfs);
1215         deactivate_locked_super(s);
1216         /*
1217          * deactivate_locked_super() invokes close_bdev_exclusive().
1218          * We must finish all post-cleaning before this call;
1219          * put_nilfs() needs the block device.
1220          */
1221         return err;
1222 }
1223
1224 struct file_system_type nilfs_fs_type = {
1225         .owner    = THIS_MODULE,
1226         .name     = "nilfs2",
1227         .get_sb   = nilfs_get_sb,
1228         .kill_sb  = kill_block_super,
1229         .fs_flags = FS_REQUIRES_DEV,
1230 };
1231
1232 static void nilfs_inode_init_once(void *obj)
1233 {
1234         struct nilfs_inode_info *ii = obj;
1235
1236         INIT_LIST_HEAD(&ii->i_dirty);
1237 #ifdef CONFIG_NILFS_XATTR
1238         init_rwsem(&ii->xattr_sem);
1239 #endif
1240         nilfs_btnode_cache_init_once(&ii->i_btnode_cache);
1241         ii->i_bmap = &ii->i_bmap_data;
1242         inode_init_once(&ii->vfs_inode);
1243 }
1244
1245 static void nilfs_segbuf_init_once(void *obj)
1246 {
1247         memset(obj, 0, sizeof(struct nilfs_segment_buffer));
1248 }
1249
1250 static void nilfs_destroy_cachep(void)
1251 {
1252         if (nilfs_inode_cachep)
1253                 kmem_cache_destroy(nilfs_inode_cachep);
1254         if (nilfs_transaction_cachep)
1255                 kmem_cache_destroy(nilfs_transaction_cachep);
1256         if (nilfs_segbuf_cachep)
1257                 kmem_cache_destroy(nilfs_segbuf_cachep);
1258         if (nilfs_btree_path_cache)
1259                 kmem_cache_destroy(nilfs_btree_path_cache);
1260 }
1261
1262 static int __init nilfs_init_cachep(void)
1263 {
1264         nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache",
1265                         sizeof(struct nilfs_inode_info), 0,
1266                         SLAB_RECLAIM_ACCOUNT, nilfs_inode_init_once);
1267         if (!nilfs_inode_cachep)
1268                 goto fail;
1269
1270         nilfs_transaction_cachep = kmem_cache_create("nilfs2_transaction_cache",
1271                         sizeof(struct nilfs_transaction_info), 0,
1272                         SLAB_RECLAIM_ACCOUNT, NULL);
1273         if (!nilfs_transaction_cachep)
1274                 goto fail;
1275
1276         nilfs_segbuf_cachep = kmem_cache_create("nilfs2_segbuf_cache",
1277                         sizeof(struct nilfs_segment_buffer), 0,
1278                         SLAB_RECLAIM_ACCOUNT, nilfs_segbuf_init_once);
1279         if (!nilfs_segbuf_cachep)
1280                 goto fail;
1281
1282         nilfs_btree_path_cache = kmem_cache_create("nilfs2_btree_path_cache",
1283                         sizeof(struct nilfs_btree_path) * NILFS_BTREE_LEVEL_MAX,
1284                         0, 0, NULL);
1285         if (!nilfs_btree_path_cache)
1286                 goto fail;
1287
1288         return 0;
1289
1290 fail:
1291         nilfs_destroy_cachep();
1292         return -ENOMEM;
1293 }
1294
1295 static int __init init_nilfs_fs(void)
1296 {
1297         int err;
1298
1299         err = nilfs_init_cachep();
1300         if (err)
1301                 goto fail;
1302
1303         err = register_filesystem(&nilfs_fs_type);
1304         if (err)
1305                 goto free_cachep;
1306
1307         printk(KERN_INFO "NILFS version 2 loaded\n");
1308         return 0;
1309
1310 free_cachep:
1311         nilfs_destroy_cachep();
1312 fail:
1313         return err;
1314 }
1315
1316 static void __exit exit_nilfs_fs(void)
1317 {
1318         nilfs_destroy_cachep();
1319         unregister_filesystem(&nilfs_fs_type);
1320 }
1321
1322 module_init(init_nilfs_fs)
1323 module_exit(exit_nilfs_fs)