2 * super.c - NILFS module and super block management.
4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
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.
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.
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
20 * Written by Ryusuke Konishi <ryusuke@osrg.net>
23 * linux/fs/ext2/super.c
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)
32 * linux/fs/minix/inode.c
34 * Copyright (C) 1991, 1992 Linus Torvalds
36 * Big-endian to little-endian byte-swapping/bitmaps by
37 * David S. Miller (davem@caip.rutgers.edu), 1995
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>
65 MODULE_AUTHOR("NTT Corp.");
66 MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem "
68 MODULE_LICENSE("GPL");
70 struct kmem_cache
*nilfs_inode_cachep
;
71 struct kmem_cache
*nilfs_transaction_cachep
;
72 struct kmem_cache
*nilfs_segbuf_cachep
;
73 struct kmem_cache
*nilfs_btree_path_cache
;
75 static int nilfs_remount(struct super_block
*sb
, int *flags
, char *data
);
77 static void nilfs_set_error(struct nilfs_sb_info
*sbi
)
79 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
80 struct nilfs_super_block
**sbp
;
82 down_write(&nilfs
->ns_sem
);
83 if (!(nilfs
->ns_mount_state
& NILFS_ERROR_FS
)) {
84 nilfs
->ns_mount_state
|= NILFS_ERROR_FS
;
85 sbp
= nilfs_prepare_super(sbi
, 0);
87 sbp
[0]->s_state
|= cpu_to_le16(NILFS_ERROR_FS
);
89 sbp
[1]->s_state
|= cpu_to_le16(NILFS_ERROR_FS
);
90 nilfs_commit_super(sbi
, NILFS_SB_COMMIT_ALL
);
93 up_write(&nilfs
->ns_sem
);
97 * nilfs_error() - report failure condition on a filesystem
99 * nilfs_error() sets an ERROR_FS flag on the superblock as well as
100 * reporting an error message. It should be called when NILFS detects
101 * incoherences or defects of meta data on disk. As for sustainable
102 * errors such as a single-shot I/O error, nilfs_warning() or the printk()
103 * function should be used instead.
105 * The segment constructor must not call this function because it can
108 void nilfs_error(struct super_block
*sb
, const char *function
,
109 const char *fmt
, ...)
111 struct nilfs_sb_info
*sbi
= NILFS_SB(sb
);
115 printk(KERN_CRIT
"NILFS error (device %s): %s: ", sb
->s_id
, function
);
120 if (!(sb
->s_flags
& MS_RDONLY
)) {
121 nilfs_set_error(sbi
);
123 if (nilfs_test_opt(sbi
, ERRORS_RO
)) {
124 printk(KERN_CRIT
"Remounting filesystem read-only\n");
125 sb
->s_flags
|= MS_RDONLY
;
129 if (nilfs_test_opt(sbi
, ERRORS_PANIC
))
130 panic("NILFS (device %s): panic forced after error\n",
134 void nilfs_warning(struct super_block
*sb
, const char *function
,
135 const char *fmt
, ...)
140 printk(KERN_WARNING
"NILFS warning (device %s): %s: ",
148 struct inode
*nilfs_alloc_inode_common(struct the_nilfs
*nilfs
)
150 struct nilfs_inode_info
*ii
;
152 ii
= kmem_cache_alloc(nilfs_inode_cachep
, GFP_NOFS
);
157 ii
->vfs_inode
.i_version
= 1;
158 nilfs_btnode_cache_init(&ii
->i_btnode_cache
, nilfs
->ns_bdi
);
159 return &ii
->vfs_inode
;
162 struct inode
*nilfs_alloc_inode(struct super_block
*sb
)
164 return nilfs_alloc_inode_common(NILFS_SB(sb
)->s_nilfs
);
167 void nilfs_destroy_inode(struct inode
*inode
)
169 kmem_cache_free(nilfs_inode_cachep
, NILFS_I(inode
));
172 static void nilfs_clear_inode(struct inode
*inode
)
174 struct nilfs_inode_info
*ii
= NILFS_I(inode
);
177 * Free resources allocated in nilfs_read_inode(), here.
179 BUG_ON(!list_empty(&ii
->i_dirty
));
183 if (test_bit(NILFS_I_BMAP
, &ii
->i_state
))
184 nilfs_bmap_clear(ii
->i_bmap
);
186 nilfs_btnode_cache_clear(&ii
->i_btnode_cache
);
189 static int nilfs_sync_super(struct nilfs_sb_info
*sbi
, int flag
)
191 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
193 int barrier_done
= 0;
195 if (nilfs_test_opt(sbi
, BARRIER
)) {
196 set_buffer_ordered(nilfs
->ns_sbh
[0]);
200 set_buffer_dirty(nilfs
->ns_sbh
[0]);
201 err
= sync_dirty_buffer(nilfs
->ns_sbh
[0]);
202 if (err
== -EOPNOTSUPP
&& barrier_done
) {
203 nilfs_warning(sbi
->s_super
, __func__
,
204 "barrier-based sync failed. "
205 "disabling barriers\n");
206 nilfs_clear_opt(sbi
, BARRIER
);
208 clear_buffer_ordered(nilfs
->ns_sbh
[0]);
213 "NILFS: unable to write superblock (err=%d)\n", err
);
214 if (err
== -EIO
&& nilfs
->ns_sbh
[1]) {
216 * sbp[0] points to newer log than sbp[1],
217 * so copy sbp[0] to sbp[1] to take over sbp[0].
219 memcpy(nilfs
->ns_sbp
[1], nilfs
->ns_sbp
[0],
221 nilfs_fall_back_super_block(nilfs
);
225 struct nilfs_super_block
*sbp
= nilfs
->ns_sbp
[0];
227 nilfs
->ns_sbwcount
++;
230 * The latest segment becomes trailable from the position
231 * written in superblock.
233 clear_nilfs_discontinued(nilfs
);
235 /* update GC protection for recent segments */
236 if (nilfs
->ns_sbh
[1]) {
237 if (flag
== NILFS_SB_COMMIT_ALL
) {
238 set_buffer_dirty(nilfs
->ns_sbh
[1]);
239 if (sync_dirty_buffer(nilfs
->ns_sbh
[1]) < 0)
242 if (le64_to_cpu(nilfs
->ns_sbp
[1]->s_last_cno
) <
243 le64_to_cpu(nilfs
->ns_sbp
[0]->s_last_cno
))
244 sbp
= nilfs
->ns_sbp
[1];
247 spin_lock(&nilfs
->ns_last_segment_lock
);
248 nilfs
->ns_prot_seq
= le64_to_cpu(sbp
->s_last_seq
);
249 spin_unlock(&nilfs
->ns_last_segment_lock
);
255 void nilfs_set_log_cursor(struct nilfs_super_block
*sbp
,
256 struct the_nilfs
*nilfs
)
258 sector_t nfreeblocks
;
260 /* nilfs->ns_sem must be locked by the caller. */
261 nilfs_count_free_blocks(nilfs
, &nfreeblocks
);
262 sbp
->s_free_blocks_count
= cpu_to_le64(nfreeblocks
);
264 spin_lock(&nilfs
->ns_last_segment_lock
);
265 sbp
->s_last_seq
= cpu_to_le64(nilfs
->ns_last_seq
);
266 sbp
->s_last_pseg
= cpu_to_le64(nilfs
->ns_last_pseg
);
267 sbp
->s_last_cno
= cpu_to_le64(nilfs
->ns_last_cno
);
268 spin_unlock(&nilfs
->ns_last_segment_lock
);
271 struct nilfs_super_block
**nilfs_prepare_super(struct nilfs_sb_info
*sbi
,
274 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
275 struct nilfs_super_block
**sbp
= nilfs
->ns_sbp
;
277 /* nilfs->ns_sem must be locked by the caller. */
278 if (sbp
[0]->s_magic
!= cpu_to_le16(NILFS_SUPER_MAGIC
)) {
280 sbp
[1]->s_magic
== cpu_to_le16(NILFS_SUPER_MAGIC
)) {
281 memcpy(sbp
[0], sbp
[1], nilfs
->ns_sbsize
);
283 printk(KERN_CRIT
"NILFS: superblock broke on dev %s\n",
288 sbp
[1]->s_magic
!= cpu_to_le16(NILFS_SUPER_MAGIC
)) {
289 memcpy(sbp
[1], sbp
[0], nilfs
->ns_sbsize
);
293 nilfs_swap_super_block(nilfs
);
298 int nilfs_commit_super(struct nilfs_sb_info
*sbi
, int flag
)
300 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
301 struct nilfs_super_block
**sbp
= nilfs
->ns_sbp
;
304 /* nilfs->ns_sem must be locked by the caller. */
306 nilfs
->ns_sbwtime
= t
;
307 sbp
[0]->s_wtime
= cpu_to_le64(t
);
309 sbp
[0]->s_sum
= cpu_to_le32(crc32_le(nilfs
->ns_crc_seed
,
310 (unsigned char *)sbp
[0],
312 if (flag
== NILFS_SB_COMMIT_ALL
&& sbp
[1]) {
313 sbp
[1]->s_wtime
= sbp
[0]->s_wtime
;
315 sbp
[1]->s_sum
= cpu_to_le32(crc32_le(nilfs
->ns_crc_seed
,
316 (unsigned char *)sbp
[1],
319 clear_nilfs_sb_dirty(nilfs
);
320 return nilfs_sync_super(sbi
, flag
);
324 * nilfs_cleanup_super() - write filesystem state for cleanup
325 * @sbi: nilfs_sb_info to be unmounted or degraded to read-only
327 * This function restores state flags in the on-disk super block.
328 * This will set "clean" flag (i.e. NILFS_VALID_FS) unless the
329 * filesystem was not clean previously.
331 int nilfs_cleanup_super(struct nilfs_sb_info
*sbi
)
333 struct nilfs_super_block
**sbp
;
334 int flag
= NILFS_SB_COMMIT
;
337 sbp
= nilfs_prepare_super(sbi
, 0);
339 sbp
[0]->s_state
= cpu_to_le16(sbi
->s_nilfs
->ns_mount_state
);
340 nilfs_set_log_cursor(sbp
[0], sbi
->s_nilfs
);
341 if (sbp
[1] && sbp
[0]->s_last_cno
== sbp
[1]->s_last_cno
) {
343 * make the "clean" flag also to the opposite
344 * super block if both super blocks point to
345 * the same checkpoint.
347 sbp
[1]->s_state
= sbp
[0]->s_state
;
348 flag
= NILFS_SB_COMMIT_ALL
;
350 ret
= nilfs_commit_super(sbi
, flag
);
355 static void nilfs_put_super(struct super_block
*sb
)
357 struct nilfs_sb_info
*sbi
= NILFS_SB(sb
);
358 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
362 nilfs_detach_segment_constructor(sbi
);
364 if (!(sb
->s_flags
& MS_RDONLY
)) {
365 down_write(&nilfs
->ns_sem
);
366 nilfs_cleanup_super(sbi
);
367 up_write(&nilfs
->ns_sem
);
369 down_write(&nilfs
->ns_super_sem
);
370 if (nilfs
->ns_current
== sbi
)
371 nilfs
->ns_current
= NULL
;
372 up_write(&nilfs
->ns_super_sem
);
374 nilfs_detach_checkpoint(sbi
);
375 put_nilfs(sbi
->s_nilfs
);
377 sb
->s_fs_info
= NULL
;
378 nilfs_put_sbinfo(sbi
);
383 static int nilfs_sync_fs(struct super_block
*sb
, int wait
)
385 struct nilfs_sb_info
*sbi
= NILFS_SB(sb
);
386 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
387 struct nilfs_super_block
**sbp
;
390 /* This function is called when super block should be written back */
392 err
= nilfs_construct_segment(sb
);
394 down_write(&nilfs
->ns_sem
);
395 if (nilfs_sb_dirty(nilfs
)) {
396 sbp
= nilfs_prepare_super(sbi
, nilfs_sb_will_flip(nilfs
));
398 nilfs_set_log_cursor(sbp
[0], nilfs
);
399 nilfs_commit_super(sbi
, NILFS_SB_COMMIT
);
402 up_write(&nilfs
->ns_sem
);
407 int nilfs_attach_checkpoint(struct nilfs_sb_info
*sbi
, __u64 cno
)
409 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
410 struct nilfs_checkpoint
*raw_cp
;
411 struct buffer_head
*bh_cp
;
414 down_write(&nilfs
->ns_super_sem
);
415 list_add(&sbi
->s_list
, &nilfs
->ns_supers
);
416 up_write(&nilfs
->ns_super_sem
);
418 sbi
->s_ifile
= nilfs_ifile_new(sbi
, nilfs
->ns_inode_size
);
422 down_read(&nilfs
->ns_segctor_sem
);
423 err
= nilfs_cpfile_get_checkpoint(nilfs
->ns_cpfile
, cno
, 0, &raw_cp
,
425 up_read(&nilfs
->ns_segctor_sem
);
427 if (err
== -ENOENT
|| err
== -EINVAL
) {
429 "NILFS: Invalid checkpoint "
430 "(checkpoint number=%llu)\n",
431 (unsigned long long)cno
);
436 err
= nilfs_read_inode_common(sbi
->s_ifile
, &raw_cp
->cp_ifile_inode
);
439 atomic_set(&sbi
->s_inodes_count
, le64_to_cpu(raw_cp
->cp_inodes_count
));
440 atomic_set(&sbi
->s_blocks_count
, le64_to_cpu(raw_cp
->cp_blocks_count
));
442 nilfs_cpfile_put_checkpoint(nilfs
->ns_cpfile
, cno
, bh_cp
);
446 nilfs_cpfile_put_checkpoint(nilfs
->ns_cpfile
, cno
, bh_cp
);
448 nilfs_mdt_destroy(sbi
->s_ifile
);
451 down_write(&nilfs
->ns_super_sem
);
452 list_del_init(&sbi
->s_list
);
453 up_write(&nilfs
->ns_super_sem
);
458 void nilfs_detach_checkpoint(struct nilfs_sb_info
*sbi
)
460 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
462 nilfs_mdt_destroy(sbi
->s_ifile
);
464 down_write(&nilfs
->ns_super_sem
);
465 list_del_init(&sbi
->s_list
);
466 up_write(&nilfs
->ns_super_sem
);
469 static int nilfs_statfs(struct dentry
*dentry
, struct kstatfs
*buf
)
471 struct super_block
*sb
= dentry
->d_sb
;
472 struct nilfs_sb_info
*sbi
= NILFS_SB(sb
);
473 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
474 u64 id
= huge_encode_dev(sb
->s_bdev
->bd_dev
);
475 unsigned long long blocks
;
476 unsigned long overhead
;
477 unsigned long nrsvblocks
;
478 sector_t nfreeblocks
;
482 * Compute all of the segment blocks
484 * The blocks before first segment and after last segment
487 blocks
= nilfs
->ns_blocks_per_segment
* nilfs
->ns_nsegments
488 - nilfs
->ns_first_data_block
;
489 nrsvblocks
= nilfs
->ns_nrsvsegs
* nilfs
->ns_blocks_per_segment
;
492 * Compute the overhead
494 * When distributing meta data blocks outside segment structure,
495 * We must count them as the overhead.
499 err
= nilfs_count_free_blocks(nilfs
, &nfreeblocks
);
503 buf
->f_type
= NILFS_SUPER_MAGIC
;
504 buf
->f_bsize
= sb
->s_blocksize
;
505 buf
->f_blocks
= blocks
- overhead
;
506 buf
->f_bfree
= nfreeblocks
;
507 buf
->f_bavail
= (buf
->f_bfree
>= nrsvblocks
) ?
508 (buf
->f_bfree
- nrsvblocks
) : 0;
509 buf
->f_files
= atomic_read(&sbi
->s_inodes_count
);
510 buf
->f_ffree
= 0; /* nilfs_count_free_inodes(sb); */
511 buf
->f_namelen
= NILFS_NAME_LEN
;
512 buf
->f_fsid
.val
[0] = (u32
)id
;
513 buf
->f_fsid
.val
[1] = (u32
)(id
>> 32);
518 static int nilfs_show_options(struct seq_file
*seq
, struct vfsmount
*vfs
)
520 struct super_block
*sb
= vfs
->mnt_sb
;
521 struct nilfs_sb_info
*sbi
= NILFS_SB(sb
);
523 if (!nilfs_test_opt(sbi
, BARRIER
))
524 seq_printf(seq
, ",nobarrier");
525 if (nilfs_test_opt(sbi
, SNAPSHOT
))
526 seq_printf(seq
, ",cp=%llu",
527 (unsigned long long int)sbi
->s_snapshot_cno
);
528 if (nilfs_test_opt(sbi
, ERRORS_PANIC
))
529 seq_printf(seq
, ",errors=panic");
530 if (nilfs_test_opt(sbi
, ERRORS_CONT
))
531 seq_printf(seq
, ",errors=continue");
532 if (nilfs_test_opt(sbi
, STRICT_ORDER
))
533 seq_printf(seq
, ",order=strict");
534 if (nilfs_test_opt(sbi
, NORECOVERY
))
535 seq_printf(seq
, ",norecovery");
536 if (nilfs_test_opt(sbi
, DISCARD
))
537 seq_printf(seq
, ",discard");
542 static const struct super_operations nilfs_sops
= {
543 .alloc_inode
= nilfs_alloc_inode
,
544 .destroy_inode
= nilfs_destroy_inode
,
545 .dirty_inode
= nilfs_dirty_inode
,
546 /* .write_inode = nilfs_write_inode, */
547 /* .put_inode = nilfs_put_inode, */
548 /* .drop_inode = nilfs_drop_inode, */
549 .delete_inode
= nilfs_delete_inode
,
550 .put_super
= nilfs_put_super
,
551 /* .write_super = nilfs_write_super, */
552 .sync_fs
= nilfs_sync_fs
,
553 /* .write_super_lockfs */
555 .statfs
= nilfs_statfs
,
556 .remount_fs
= nilfs_remount
,
557 .clear_inode
= nilfs_clear_inode
,
559 .show_options
= nilfs_show_options
562 static struct inode
*
563 nilfs_nfs_get_inode(struct super_block
*sb
, u64 ino
, u32 generation
)
567 if (ino
< NILFS_FIRST_INO(sb
) && ino
!= NILFS_ROOT_INO
&&
568 ino
!= NILFS_SKETCH_INO
)
569 return ERR_PTR(-ESTALE
);
571 inode
= nilfs_iget(sb
, ino
);
573 return ERR_CAST(inode
);
574 if (generation
&& inode
->i_generation
!= generation
) {
576 return ERR_PTR(-ESTALE
);
582 static struct dentry
*
583 nilfs_fh_to_dentry(struct super_block
*sb
, struct fid
*fid
, int fh_len
,
586 return generic_fh_to_dentry(sb
, fid
, fh_len
, fh_type
,
587 nilfs_nfs_get_inode
);
590 static struct dentry
*
591 nilfs_fh_to_parent(struct super_block
*sb
, struct fid
*fid
, int fh_len
,
594 return generic_fh_to_parent(sb
, fid
, fh_len
, fh_type
,
595 nilfs_nfs_get_inode
);
598 static const struct export_operations nilfs_export_ops
= {
599 .fh_to_dentry
= nilfs_fh_to_dentry
,
600 .fh_to_parent
= nilfs_fh_to_parent
,
601 .get_parent
= nilfs_get_parent
,
605 Opt_err_cont
, Opt_err_panic
, Opt_err_ro
,
606 Opt_barrier
, Opt_nobarrier
, Opt_snapshot
, Opt_order
, Opt_norecovery
,
607 Opt_discard
, Opt_err
,
610 static match_table_t tokens
= {
611 {Opt_err_cont
, "errors=continue"},
612 {Opt_err_panic
, "errors=panic"},
613 {Opt_err_ro
, "errors=remount-ro"},
614 {Opt_barrier
, "barrier"},
615 {Opt_nobarrier
, "nobarrier"},
616 {Opt_snapshot
, "cp=%u"},
617 {Opt_order
, "order=%s"},
618 {Opt_norecovery
, "norecovery"},
619 {Opt_discard
, "discard"},
623 static int parse_options(char *options
, struct super_block
*sb
)
625 struct nilfs_sb_info
*sbi
= NILFS_SB(sb
);
627 substring_t args
[MAX_OPT_ARGS
];
633 while ((p
= strsep(&options
, ",")) != NULL
) {
638 token
= match_token(p
, tokens
, args
);
641 nilfs_set_opt(sbi
, BARRIER
);
644 nilfs_clear_opt(sbi
, BARRIER
);
647 if (strcmp(args
[0].from
, "relaxed") == 0)
648 /* Ordered data semantics */
649 nilfs_clear_opt(sbi
, STRICT_ORDER
);
650 else if (strcmp(args
[0].from
, "strict") == 0)
651 /* Strict in-order semantics */
652 nilfs_set_opt(sbi
, STRICT_ORDER
);
657 nilfs_write_opt(sbi
, ERROR_MODE
, ERRORS_PANIC
);
660 nilfs_write_opt(sbi
, ERROR_MODE
, ERRORS_RO
);
663 nilfs_write_opt(sbi
, ERROR_MODE
, ERRORS_CONT
);
666 if (match_int(&args
[0], &option
) || option
<= 0)
668 if (!(sb
->s_flags
& MS_RDONLY
))
670 sbi
->s_snapshot_cno
= option
;
671 nilfs_set_opt(sbi
, SNAPSHOT
);
674 nilfs_set_opt(sbi
, NORECOVERY
);
677 nilfs_set_opt(sbi
, DISCARD
);
681 "NILFS: Unrecognized mount option \"%s\"\n", p
);
689 nilfs_set_default_options(struct nilfs_sb_info
*sbi
,
690 struct nilfs_super_block
*sbp
)
693 NILFS_MOUNT_ERRORS_RO
| NILFS_MOUNT_BARRIER
;
696 static int nilfs_setup_super(struct nilfs_sb_info
*sbi
)
698 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
699 struct nilfs_super_block
**sbp
;
703 /* nilfs->ns_sem must be locked by the caller. */
704 sbp
= nilfs_prepare_super(sbi
, 0);
708 max_mnt_count
= le16_to_cpu(sbp
[0]->s_max_mnt_count
);
709 mnt_count
= le16_to_cpu(sbp
[0]->s_mnt_count
);
711 if (nilfs
->ns_mount_state
& NILFS_ERROR_FS
) {
713 "NILFS warning: mounting fs with errors\n");
715 } else if (max_mnt_count
>= 0 && mnt_count
>= max_mnt_count
) {
717 "NILFS warning: maximal mount count reached\n");
721 sbp
[0]->s_max_mnt_count
= cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT
);
723 sbp
[0]->s_mnt_count
= cpu_to_le16(mnt_count
+ 1);
725 cpu_to_le16(le16_to_cpu(sbp
[0]->s_state
) & ~NILFS_VALID_FS
);
726 sbp
[0]->s_mtime
= cpu_to_le64(get_seconds());
727 /* synchronize sbp[1] with sbp[0] */
728 memcpy(sbp
[1], sbp
[0], nilfs
->ns_sbsize
);
729 return nilfs_commit_super(sbi
, NILFS_SB_COMMIT_ALL
);
732 struct nilfs_super_block
*nilfs_read_super_block(struct super_block
*sb
,
733 u64 pos
, int blocksize
,
734 struct buffer_head
**pbh
)
736 unsigned long long sb_index
= pos
;
737 unsigned long offset
;
739 offset
= do_div(sb_index
, blocksize
);
740 *pbh
= sb_bread(sb
, sb_index
);
743 return (struct nilfs_super_block
*)((char *)(*pbh
)->b_data
+ offset
);
746 int nilfs_store_magic_and_option(struct super_block
*sb
,
747 struct nilfs_super_block
*sbp
,
750 struct nilfs_sb_info
*sbi
= NILFS_SB(sb
);
752 sb
->s_magic
= le16_to_cpu(sbp
->s_magic
);
754 /* FS independent flags */
755 #ifdef NILFS_ATIME_DISABLE
756 sb
->s_flags
|= MS_NOATIME
;
759 nilfs_set_default_options(sbi
, sbp
);
761 sbi
->s_resuid
= le16_to_cpu(sbp
->s_def_resuid
);
762 sbi
->s_resgid
= le16_to_cpu(sbp
->s_def_resgid
);
763 sbi
->s_interval
= le32_to_cpu(sbp
->s_c_interval
);
764 sbi
->s_watermark
= le32_to_cpu(sbp
->s_c_block_max
);
766 return !parse_options(data
, sb
) ? -EINVAL
: 0 ;
770 * nilfs_fill_super() - initialize a super block instance
772 * @data: mount options
773 * @silent: silent mode flag
774 * @nilfs: the_nilfs struct
776 * This function is called exclusively by nilfs->ns_mount_mutex.
777 * So, the recovery process is protected from other simultaneous mounts.
780 nilfs_fill_super(struct super_block
*sb
, void *data
, int silent
,
781 struct the_nilfs
*nilfs
)
783 struct nilfs_sb_info
*sbi
;
788 sbi
= kzalloc(sizeof(*sbi
), GFP_KERNEL
);
795 sbi
->s_nilfs
= nilfs
;
797 atomic_set(&sbi
->s_count
, 1);
799 err
= init_nilfs(nilfs
, sbi
, (char *)data
);
803 spin_lock_init(&sbi
->s_inode_lock
);
804 INIT_LIST_HEAD(&sbi
->s_dirty_files
);
805 INIT_LIST_HEAD(&sbi
->s_list
);
808 * Following initialization is overlapped because
809 * nilfs_sb_info structure has been cleared at the beginning.
810 * But we reserve them to keep our interest and make ready
811 * for the future change.
813 get_random_bytes(&sbi
->s_next_generation
,
814 sizeof(sbi
->s_next_generation
));
815 spin_lock_init(&sbi
->s_next_gen_lock
);
817 sb
->s_op
= &nilfs_sops
;
818 sb
->s_export_op
= &nilfs_export_ops
;
821 sb
->s_bdi
= nilfs
->ns_bdi
;
823 err
= load_nilfs(nilfs
, sbi
);
827 cno
= nilfs_last_cno(nilfs
);
829 if (sb
->s_flags
& MS_RDONLY
) {
830 if (nilfs_test_opt(sbi
, SNAPSHOT
)) {
831 down_read(&nilfs
->ns_segctor_sem
);
832 err
= nilfs_cpfile_is_snapshot(nilfs
->ns_cpfile
,
833 sbi
->s_snapshot_cno
);
834 up_read(&nilfs
->ns_segctor_sem
);
842 "NILFS: The specified checkpoint is "
844 "(checkpoint number=%llu).\n",
845 (unsigned long long)sbi
->s_snapshot_cno
);
849 cno
= sbi
->s_snapshot_cno
;
853 err
= nilfs_attach_checkpoint(sbi
, cno
);
855 printk(KERN_ERR
"NILFS: error loading a checkpoint"
856 " (checkpoint number=%llu).\n", (unsigned long long)cno
);
860 if (!(sb
->s_flags
& MS_RDONLY
)) {
861 err
= nilfs_attach_segment_constructor(sbi
);
863 goto failed_checkpoint
;
866 root
= nilfs_iget(sb
, NILFS_ROOT_INO
);
868 printk(KERN_ERR
"NILFS: get root inode failed\n");
872 if (!S_ISDIR(root
->i_mode
) || !root
->i_blocks
|| !root
->i_size
) {
874 printk(KERN_ERR
"NILFS: corrupt root inode.\n");
878 sb
->s_root
= d_alloc_root(root
);
881 printk(KERN_ERR
"NILFS: get root dentry failed\n");
886 if (!(sb
->s_flags
& MS_RDONLY
)) {
887 down_write(&nilfs
->ns_sem
);
888 nilfs_setup_super(sbi
);
889 up_write(&nilfs
->ns_sem
);
892 down_write(&nilfs
->ns_super_sem
);
893 if (!nilfs_test_opt(sbi
, SNAPSHOT
))
894 nilfs
->ns_current
= sbi
;
895 up_write(&nilfs
->ns_super_sem
);
900 nilfs_detach_segment_constructor(sbi
);
903 nilfs_detach_checkpoint(sbi
);
907 sb
->s_fs_info
= NULL
;
908 nilfs_put_sbinfo(sbi
);
912 static int nilfs_remount(struct super_block
*sb
, int *flags
, char *data
)
914 struct nilfs_sb_info
*sbi
= NILFS_SB(sb
);
915 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
916 unsigned long old_sb_flags
;
917 struct nilfs_mount_options old_opts
;
918 int was_snapshot
, err
;
922 down_write(&nilfs
->ns_super_sem
);
923 old_sb_flags
= sb
->s_flags
;
924 old_opts
.mount_opt
= sbi
->s_mount_opt
;
925 old_opts
.snapshot_cno
= sbi
->s_snapshot_cno
;
926 was_snapshot
= nilfs_test_opt(sbi
, SNAPSHOT
);
928 if (!parse_options(data
, sb
)) {
932 sb
->s_flags
= (sb
->s_flags
& ~MS_POSIXACL
);
936 if (!(*flags
& MS_RDONLY
)) {
937 printk(KERN_ERR
"NILFS (device %s): cannot remount "
938 "snapshot read/write.\n",
941 } else if (sbi
->s_snapshot_cno
!= old_opts
.snapshot_cno
) {
942 printk(KERN_ERR
"NILFS (device %s): cannot "
943 "remount to a different snapshot.\n",
948 if (nilfs_test_opt(sbi
, SNAPSHOT
)) {
949 printk(KERN_ERR
"NILFS (device %s): cannot change "
950 "a regular mount to a snapshot.\n",
956 if (!nilfs_valid_fs(nilfs
)) {
957 printk(KERN_WARNING
"NILFS (device %s): couldn't "
958 "remount because the filesystem is in an "
959 "incomplete recovery state.\n", sb
->s_id
);
963 if ((*flags
& MS_RDONLY
) == (sb
->s_flags
& MS_RDONLY
))
965 if (*flags
& MS_RDONLY
) {
966 /* Shutting down the segment constructor */
967 nilfs_detach_segment_constructor(sbi
);
968 sb
->s_flags
|= MS_RDONLY
;
971 * Remounting a valid RW partition RDONLY, so set
972 * the RDONLY flag and then mark the partition as valid again.
974 down_write(&nilfs
->ns_sem
);
975 nilfs_cleanup_super(sbi
);
976 up_write(&nilfs
->ns_sem
);
979 * Mounting a RDONLY partition read-write, so reread and
980 * store the current valid flag. (It may have been changed
981 * by fsck since we originally mounted the partition.)
983 sb
->s_flags
&= ~MS_RDONLY
;
985 err
= nilfs_attach_segment_constructor(sbi
);
989 down_write(&nilfs
->ns_sem
);
990 nilfs_setup_super(sbi
);
991 up_write(&nilfs
->ns_sem
);
994 up_write(&nilfs
->ns_super_sem
);
999 sb
->s_flags
= old_sb_flags
;
1000 sbi
->s_mount_opt
= old_opts
.mount_opt
;
1001 sbi
->s_snapshot_cno
= old_opts
.snapshot_cno
;
1002 up_write(&nilfs
->ns_super_sem
);
1007 struct nilfs_super_data
{
1008 struct block_device
*bdev
;
1009 struct nilfs_sb_info
*sbi
;
1015 * nilfs_identify - pre-read mount options needed to identify mount instance
1016 * @data: mount options
1017 * @sd: nilfs_super_data
1019 static int nilfs_identify(char *data
, struct nilfs_super_data
*sd
)
1021 char *p
, *options
= data
;
1022 substring_t args
[MAX_OPT_ARGS
];
1027 p
= strsep(&options
, ",");
1028 if (p
!= NULL
&& *p
) {
1029 token
= match_token(p
, tokens
, args
);
1030 if (token
== Opt_snapshot
) {
1031 if (!(sd
->flags
& MS_RDONLY
))
1034 ret
= match_int(&args
[0], &option
);
1045 "NILFS: invalid mount option: %s\n", p
);
1049 BUG_ON(options
== data
);
1050 *(options
- 1) = ',';
1055 static int nilfs_set_bdev_super(struct super_block
*s
, void *data
)
1057 struct nilfs_super_data
*sd
= data
;
1059 s
->s_bdev
= sd
->bdev
;
1060 s
->s_dev
= s
->s_bdev
->bd_dev
;
1064 static int nilfs_test_bdev_super(struct super_block
*s
, void *data
)
1066 struct nilfs_super_data
*sd
= data
;
1068 return sd
->sbi
&& s
->s_fs_info
== (void *)sd
->sbi
;
1072 nilfs_get_sb(struct file_system_type
*fs_type
, int flags
,
1073 const char *dev_name
, void *data
, struct vfsmount
*mnt
)
1075 struct nilfs_super_data sd
;
1076 struct super_block
*s
;
1077 fmode_t mode
= FMODE_READ
;
1078 struct the_nilfs
*nilfs
;
1079 int err
, need_to_close
= 1;
1081 if (!(flags
& MS_RDONLY
))
1082 mode
|= FMODE_WRITE
;
1084 sd
.bdev
= open_bdev_exclusive(dev_name
, mode
, fs_type
);
1085 if (IS_ERR(sd
.bdev
))
1086 return PTR_ERR(sd
.bdev
);
1089 * To get mount instance using sget() vfs-routine, NILFS needs
1090 * much more information than normal filesystems to identify mount
1091 * instance. For snapshot mounts, not only a mount type (ro-mount
1092 * or rw-mount) but also a checkpoint number is required.
1096 if (nilfs_identify((char *)data
, &sd
)) {
1101 nilfs
= find_or_create_nilfs(sd
.bdev
);
1107 mutex_lock(&nilfs
->ns_mount_mutex
);
1111 * Check if an exclusive mount exists or not.
1112 * Snapshot mounts coexist with a current mount
1113 * (i.e. rw-mount or ro-mount), whereas rw-mount and
1114 * ro-mount are mutually exclusive.
1116 down_read(&nilfs
->ns_super_sem
);
1117 if (nilfs
->ns_current
&&
1118 ((nilfs
->ns_current
->s_super
->s_flags
^ flags
)
1120 up_read(&nilfs
->ns_super_sem
);
1124 up_read(&nilfs
->ns_super_sem
);
1128 * Find existing nilfs_sb_info struct
1130 sd
.sbi
= nilfs_find_sbinfo(nilfs
, !(flags
& MS_RDONLY
), sd
.cno
);
1133 * Get super block instance holding the nilfs_sb_info struct.
1134 * A new instance is allocated if no existing mount is present or
1135 * existing instance has been unmounted.
1137 s
= sget(fs_type
, nilfs_test_bdev_super
, nilfs_set_bdev_super
, &sd
);
1139 nilfs_put_sbinfo(sd
.sbi
);
1147 char b
[BDEVNAME_SIZE
];
1149 /* New superblock instance created */
1152 strlcpy(s
->s_id
, bdevname(sd
.bdev
, b
), sizeof(s
->s_id
));
1153 sb_set_blocksize(s
, block_size(sd
.bdev
));
1155 err
= nilfs_fill_super(s
, data
, flags
& MS_SILENT
? 1 : 0,
1160 s
->s_flags
|= MS_ACTIVE
;
1164 mutex_unlock(&nilfs
->ns_mount_mutex
);
1167 close_bdev_exclusive(sd
.bdev
, mode
);
1168 simple_set_mnt(mnt
, s
);
1172 mutex_unlock(&nilfs
->ns_mount_mutex
);
1175 close_bdev_exclusive(sd
.bdev
, mode
);
1180 /* Abandoning the newly allocated superblock */
1181 mutex_unlock(&nilfs
->ns_mount_mutex
);
1183 deactivate_locked_super(s
);
1185 * deactivate_locked_super() invokes close_bdev_exclusive().
1186 * We must finish all post-cleaning before this call;
1187 * put_nilfs() needs the block device.
1192 struct file_system_type nilfs_fs_type
= {
1193 .owner
= THIS_MODULE
,
1195 .get_sb
= nilfs_get_sb
,
1196 .kill_sb
= kill_block_super
,
1197 .fs_flags
= FS_REQUIRES_DEV
,
1200 static void nilfs_inode_init_once(void *obj
)
1202 struct nilfs_inode_info
*ii
= obj
;
1204 INIT_LIST_HEAD(&ii
->i_dirty
);
1205 #ifdef CONFIG_NILFS_XATTR
1206 init_rwsem(&ii
->xattr_sem
);
1208 nilfs_btnode_cache_init_once(&ii
->i_btnode_cache
);
1209 ii
->i_bmap
= (struct nilfs_bmap
*)&ii
->i_bmap_union
;
1210 inode_init_once(&ii
->vfs_inode
);
1213 static void nilfs_segbuf_init_once(void *obj
)
1215 memset(obj
, 0, sizeof(struct nilfs_segment_buffer
));
1218 static void nilfs_destroy_cachep(void)
1220 if (nilfs_inode_cachep
)
1221 kmem_cache_destroy(nilfs_inode_cachep
);
1222 if (nilfs_transaction_cachep
)
1223 kmem_cache_destroy(nilfs_transaction_cachep
);
1224 if (nilfs_segbuf_cachep
)
1225 kmem_cache_destroy(nilfs_segbuf_cachep
);
1226 if (nilfs_btree_path_cache
)
1227 kmem_cache_destroy(nilfs_btree_path_cache
);
1230 static int __init
nilfs_init_cachep(void)
1232 nilfs_inode_cachep
= kmem_cache_create("nilfs2_inode_cache",
1233 sizeof(struct nilfs_inode_info
), 0,
1234 SLAB_RECLAIM_ACCOUNT
, nilfs_inode_init_once
);
1235 if (!nilfs_inode_cachep
)
1238 nilfs_transaction_cachep
= kmem_cache_create("nilfs2_transaction_cache",
1239 sizeof(struct nilfs_transaction_info
), 0,
1240 SLAB_RECLAIM_ACCOUNT
, NULL
);
1241 if (!nilfs_transaction_cachep
)
1244 nilfs_segbuf_cachep
= kmem_cache_create("nilfs2_segbuf_cache",
1245 sizeof(struct nilfs_segment_buffer
), 0,
1246 SLAB_RECLAIM_ACCOUNT
, nilfs_segbuf_init_once
);
1247 if (!nilfs_segbuf_cachep
)
1250 nilfs_btree_path_cache
= kmem_cache_create("nilfs2_btree_path_cache",
1251 sizeof(struct nilfs_btree_path
) * NILFS_BTREE_LEVEL_MAX
,
1253 if (!nilfs_btree_path_cache
)
1259 nilfs_destroy_cachep();
1263 static int __init
init_nilfs_fs(void)
1267 err
= nilfs_init_cachep();
1271 err
= register_filesystem(&nilfs_fs_type
);
1275 printk(KERN_INFO
"NILFS version 2 loaded\n");
1279 nilfs_destroy_cachep();
1284 static void __exit
exit_nilfs_fs(void)
1286 nilfs_destroy_cachep();
1287 unregister_filesystem(&nilfs_fs_type
);
1290 module_init(init_nilfs_fs
)
1291 module_exit(exit_nilfs_fs
)