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_puts(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_puts(seq
, ",errors=panic");
530 if (nilfs_test_opt(sbi
, ERRORS_CONT
))
531 seq_puts(seq
, ",errors=continue");
532 if (nilfs_test_opt(sbi
, STRICT_ORDER
))
533 seq_puts(seq
, ",order=strict");
534 if (nilfs_test_opt(sbi
, NORECOVERY
))
535 seq_puts(seq
, ",norecovery");
536 if (nilfs_test_opt(sbi
, DISCARD
))
537 seq_puts(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_nodiscard
, 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"},
620 {Opt_nodiscard
, "nodiscard"},
624 static int parse_options(char *options
, struct super_block
*sb
)
626 struct nilfs_sb_info
*sbi
= NILFS_SB(sb
);
628 substring_t args
[MAX_OPT_ARGS
];
634 while ((p
= strsep(&options
, ",")) != NULL
) {
639 token
= match_token(p
, tokens
, args
);
642 nilfs_set_opt(sbi
, BARRIER
);
645 nilfs_clear_opt(sbi
, BARRIER
);
648 if (strcmp(args
[0].from
, "relaxed") == 0)
649 /* Ordered data semantics */
650 nilfs_clear_opt(sbi
, STRICT_ORDER
);
651 else if (strcmp(args
[0].from
, "strict") == 0)
652 /* Strict in-order semantics */
653 nilfs_set_opt(sbi
, STRICT_ORDER
);
658 nilfs_write_opt(sbi
, ERROR_MODE
, ERRORS_PANIC
);
661 nilfs_write_opt(sbi
, ERROR_MODE
, ERRORS_RO
);
664 nilfs_write_opt(sbi
, ERROR_MODE
, ERRORS_CONT
);
667 if (match_int(&args
[0], &option
) || option
<= 0)
669 if (!(sb
->s_flags
& MS_RDONLY
))
671 sbi
->s_snapshot_cno
= option
;
672 nilfs_set_opt(sbi
, SNAPSHOT
);
675 nilfs_set_opt(sbi
, NORECOVERY
);
678 nilfs_set_opt(sbi
, DISCARD
);
681 nilfs_clear_opt(sbi
, DISCARD
);
685 "NILFS: Unrecognized mount option \"%s\"\n", p
);
693 nilfs_set_default_options(struct nilfs_sb_info
*sbi
,
694 struct nilfs_super_block
*sbp
)
697 NILFS_MOUNT_ERRORS_RO
| NILFS_MOUNT_BARRIER
;
700 static int nilfs_setup_super(struct nilfs_sb_info
*sbi
)
702 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
703 struct nilfs_super_block
**sbp
;
707 /* nilfs->ns_sem must be locked by the caller. */
708 sbp
= nilfs_prepare_super(sbi
, 0);
712 max_mnt_count
= le16_to_cpu(sbp
[0]->s_max_mnt_count
);
713 mnt_count
= le16_to_cpu(sbp
[0]->s_mnt_count
);
715 if (nilfs
->ns_mount_state
& NILFS_ERROR_FS
) {
717 "NILFS warning: mounting fs with errors\n");
719 } else if (max_mnt_count
>= 0 && mnt_count
>= max_mnt_count
) {
721 "NILFS warning: maximal mount count reached\n");
725 sbp
[0]->s_max_mnt_count
= cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT
);
727 sbp
[0]->s_mnt_count
= cpu_to_le16(mnt_count
+ 1);
729 cpu_to_le16(le16_to_cpu(sbp
[0]->s_state
) & ~NILFS_VALID_FS
);
730 sbp
[0]->s_mtime
= cpu_to_le64(get_seconds());
731 /* synchronize sbp[1] with sbp[0] */
732 memcpy(sbp
[1], sbp
[0], nilfs
->ns_sbsize
);
733 return nilfs_commit_super(sbi
, NILFS_SB_COMMIT_ALL
);
736 struct nilfs_super_block
*nilfs_read_super_block(struct super_block
*sb
,
737 u64 pos
, int blocksize
,
738 struct buffer_head
**pbh
)
740 unsigned long long sb_index
= pos
;
741 unsigned long offset
;
743 offset
= do_div(sb_index
, blocksize
);
744 *pbh
= sb_bread(sb
, sb_index
);
747 return (struct nilfs_super_block
*)((char *)(*pbh
)->b_data
+ offset
);
750 int nilfs_store_magic_and_option(struct super_block
*sb
,
751 struct nilfs_super_block
*sbp
,
754 struct nilfs_sb_info
*sbi
= NILFS_SB(sb
);
756 sb
->s_magic
= le16_to_cpu(sbp
->s_magic
);
758 /* FS independent flags */
759 #ifdef NILFS_ATIME_DISABLE
760 sb
->s_flags
|= MS_NOATIME
;
763 nilfs_set_default_options(sbi
, sbp
);
765 sbi
->s_resuid
= le16_to_cpu(sbp
->s_def_resuid
);
766 sbi
->s_resgid
= le16_to_cpu(sbp
->s_def_resgid
);
767 sbi
->s_interval
= le32_to_cpu(sbp
->s_c_interval
);
768 sbi
->s_watermark
= le32_to_cpu(sbp
->s_c_block_max
);
770 return !parse_options(data
, sb
) ? -EINVAL
: 0 ;
774 * nilfs_fill_super() - initialize a super block instance
776 * @data: mount options
777 * @silent: silent mode flag
778 * @nilfs: the_nilfs struct
780 * This function is called exclusively by nilfs->ns_mount_mutex.
781 * So, the recovery process is protected from other simultaneous mounts.
784 nilfs_fill_super(struct super_block
*sb
, void *data
, int silent
,
785 struct the_nilfs
*nilfs
)
787 struct nilfs_sb_info
*sbi
;
792 sbi
= kzalloc(sizeof(*sbi
), GFP_KERNEL
);
799 sbi
->s_nilfs
= nilfs
;
801 atomic_set(&sbi
->s_count
, 1);
803 err
= init_nilfs(nilfs
, sbi
, (char *)data
);
807 spin_lock_init(&sbi
->s_inode_lock
);
808 INIT_LIST_HEAD(&sbi
->s_dirty_files
);
809 INIT_LIST_HEAD(&sbi
->s_list
);
812 * Following initialization is overlapped because
813 * nilfs_sb_info structure has been cleared at the beginning.
814 * But we reserve them to keep our interest and make ready
815 * for the future change.
817 get_random_bytes(&sbi
->s_next_generation
,
818 sizeof(sbi
->s_next_generation
));
819 spin_lock_init(&sbi
->s_next_gen_lock
);
821 sb
->s_op
= &nilfs_sops
;
822 sb
->s_export_op
= &nilfs_export_ops
;
825 sb
->s_bdi
= nilfs
->ns_bdi
;
827 err
= load_nilfs(nilfs
, sbi
);
831 cno
= nilfs_last_cno(nilfs
);
833 if (sb
->s_flags
& MS_RDONLY
) {
834 if (nilfs_test_opt(sbi
, SNAPSHOT
)) {
835 down_read(&nilfs
->ns_segctor_sem
);
836 err
= nilfs_cpfile_is_snapshot(nilfs
->ns_cpfile
,
837 sbi
->s_snapshot_cno
);
838 up_read(&nilfs
->ns_segctor_sem
);
846 "NILFS: The specified checkpoint is "
848 "(checkpoint number=%llu).\n",
849 (unsigned long long)sbi
->s_snapshot_cno
);
853 cno
= sbi
->s_snapshot_cno
;
857 err
= nilfs_attach_checkpoint(sbi
, cno
);
859 printk(KERN_ERR
"NILFS: error loading a checkpoint"
860 " (checkpoint number=%llu).\n", (unsigned long long)cno
);
864 if (!(sb
->s_flags
& MS_RDONLY
)) {
865 err
= nilfs_attach_segment_constructor(sbi
);
867 goto failed_checkpoint
;
870 root
= nilfs_iget(sb
, NILFS_ROOT_INO
);
872 printk(KERN_ERR
"NILFS: get root inode failed\n");
876 if (!S_ISDIR(root
->i_mode
) || !root
->i_blocks
|| !root
->i_size
) {
878 printk(KERN_ERR
"NILFS: corrupt root inode.\n");
882 sb
->s_root
= d_alloc_root(root
);
885 printk(KERN_ERR
"NILFS: get root dentry failed\n");
890 if (!(sb
->s_flags
& MS_RDONLY
)) {
891 down_write(&nilfs
->ns_sem
);
892 nilfs_setup_super(sbi
);
893 up_write(&nilfs
->ns_sem
);
896 down_write(&nilfs
->ns_super_sem
);
897 if (!nilfs_test_opt(sbi
, SNAPSHOT
))
898 nilfs
->ns_current
= sbi
;
899 up_write(&nilfs
->ns_super_sem
);
904 nilfs_detach_segment_constructor(sbi
);
907 nilfs_detach_checkpoint(sbi
);
911 sb
->s_fs_info
= NULL
;
912 nilfs_put_sbinfo(sbi
);
916 static int nilfs_remount(struct super_block
*sb
, int *flags
, char *data
)
918 struct nilfs_sb_info
*sbi
= NILFS_SB(sb
);
919 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
920 unsigned long old_sb_flags
;
921 struct nilfs_mount_options old_opts
;
922 int was_snapshot
, err
;
926 down_write(&nilfs
->ns_super_sem
);
927 old_sb_flags
= sb
->s_flags
;
928 old_opts
.mount_opt
= sbi
->s_mount_opt
;
929 old_opts
.snapshot_cno
= sbi
->s_snapshot_cno
;
930 was_snapshot
= nilfs_test_opt(sbi
, SNAPSHOT
);
932 if (!parse_options(data
, sb
)) {
936 sb
->s_flags
= (sb
->s_flags
& ~MS_POSIXACL
);
940 if (!(*flags
& MS_RDONLY
)) {
941 printk(KERN_ERR
"NILFS (device %s): cannot remount "
942 "snapshot read/write.\n",
945 } else if (sbi
->s_snapshot_cno
!= old_opts
.snapshot_cno
) {
946 printk(KERN_ERR
"NILFS (device %s): cannot "
947 "remount to a different snapshot.\n",
952 if (nilfs_test_opt(sbi
, SNAPSHOT
)) {
953 printk(KERN_ERR
"NILFS (device %s): cannot change "
954 "a regular mount to a snapshot.\n",
960 if (!nilfs_valid_fs(nilfs
)) {
961 printk(KERN_WARNING
"NILFS (device %s): couldn't "
962 "remount because the filesystem is in an "
963 "incomplete recovery state.\n", sb
->s_id
);
967 if ((*flags
& MS_RDONLY
) == (sb
->s_flags
& MS_RDONLY
))
969 if (*flags
& MS_RDONLY
) {
970 /* Shutting down the segment constructor */
971 nilfs_detach_segment_constructor(sbi
);
972 sb
->s_flags
|= MS_RDONLY
;
975 * Remounting a valid RW partition RDONLY, so set
976 * the RDONLY flag and then mark the partition as valid again.
978 down_write(&nilfs
->ns_sem
);
979 nilfs_cleanup_super(sbi
);
980 up_write(&nilfs
->ns_sem
);
983 * Mounting a RDONLY partition read-write, so reread and
984 * store the current valid flag. (It may have been changed
985 * by fsck since we originally mounted the partition.)
987 sb
->s_flags
&= ~MS_RDONLY
;
989 err
= nilfs_attach_segment_constructor(sbi
);
993 down_write(&nilfs
->ns_sem
);
994 nilfs_setup_super(sbi
);
995 up_write(&nilfs
->ns_sem
);
998 up_write(&nilfs
->ns_super_sem
);
1003 sb
->s_flags
= old_sb_flags
;
1004 sbi
->s_mount_opt
= old_opts
.mount_opt
;
1005 sbi
->s_snapshot_cno
= old_opts
.snapshot_cno
;
1006 up_write(&nilfs
->ns_super_sem
);
1011 struct nilfs_super_data
{
1012 struct block_device
*bdev
;
1013 struct nilfs_sb_info
*sbi
;
1019 * nilfs_identify - pre-read mount options needed to identify mount instance
1020 * @data: mount options
1021 * @sd: nilfs_super_data
1023 static int nilfs_identify(char *data
, struct nilfs_super_data
*sd
)
1025 char *p
, *options
= data
;
1026 substring_t args
[MAX_OPT_ARGS
];
1031 p
= strsep(&options
, ",");
1032 if (p
!= NULL
&& *p
) {
1033 token
= match_token(p
, tokens
, args
);
1034 if (token
== Opt_snapshot
) {
1035 if (!(sd
->flags
& MS_RDONLY
))
1038 ret
= match_int(&args
[0], &option
);
1049 "NILFS: invalid mount option: %s\n", p
);
1053 BUG_ON(options
== data
);
1054 *(options
- 1) = ',';
1059 static int nilfs_set_bdev_super(struct super_block
*s
, void *data
)
1061 struct nilfs_super_data
*sd
= data
;
1063 s
->s_bdev
= sd
->bdev
;
1064 s
->s_dev
= s
->s_bdev
->bd_dev
;
1068 static int nilfs_test_bdev_super(struct super_block
*s
, void *data
)
1070 struct nilfs_super_data
*sd
= data
;
1072 return sd
->sbi
&& s
->s_fs_info
== (void *)sd
->sbi
;
1076 nilfs_get_sb(struct file_system_type
*fs_type
, int flags
,
1077 const char *dev_name
, void *data
, struct vfsmount
*mnt
)
1079 struct nilfs_super_data sd
;
1080 struct super_block
*s
;
1081 fmode_t mode
= FMODE_READ
;
1082 struct the_nilfs
*nilfs
;
1083 int err
, need_to_close
= 1;
1085 if (!(flags
& MS_RDONLY
))
1086 mode
|= FMODE_WRITE
;
1088 sd
.bdev
= open_bdev_exclusive(dev_name
, mode
, fs_type
);
1089 if (IS_ERR(sd
.bdev
))
1090 return PTR_ERR(sd
.bdev
);
1093 * To get mount instance using sget() vfs-routine, NILFS needs
1094 * much more information than normal filesystems to identify mount
1095 * instance. For snapshot mounts, not only a mount type (ro-mount
1096 * or rw-mount) but also a checkpoint number is required.
1100 if (nilfs_identify((char *)data
, &sd
)) {
1105 nilfs
= find_or_create_nilfs(sd
.bdev
);
1111 mutex_lock(&nilfs
->ns_mount_mutex
);
1115 * Check if an exclusive mount exists or not.
1116 * Snapshot mounts coexist with a current mount
1117 * (i.e. rw-mount or ro-mount), whereas rw-mount and
1118 * ro-mount are mutually exclusive.
1120 down_read(&nilfs
->ns_super_sem
);
1121 if (nilfs
->ns_current
&&
1122 ((nilfs
->ns_current
->s_super
->s_flags
^ flags
)
1124 up_read(&nilfs
->ns_super_sem
);
1128 up_read(&nilfs
->ns_super_sem
);
1132 * Find existing nilfs_sb_info struct
1134 sd
.sbi
= nilfs_find_sbinfo(nilfs
, !(flags
& MS_RDONLY
), sd
.cno
);
1137 * Get super block instance holding the nilfs_sb_info struct.
1138 * A new instance is allocated if no existing mount is present or
1139 * existing instance has been unmounted.
1141 s
= sget(fs_type
, nilfs_test_bdev_super
, nilfs_set_bdev_super
, &sd
);
1143 nilfs_put_sbinfo(sd
.sbi
);
1151 char b
[BDEVNAME_SIZE
];
1153 /* New superblock instance created */
1156 strlcpy(s
->s_id
, bdevname(sd
.bdev
, b
), sizeof(s
->s_id
));
1157 sb_set_blocksize(s
, block_size(sd
.bdev
));
1159 err
= nilfs_fill_super(s
, data
, flags
& MS_SILENT
? 1 : 0,
1164 s
->s_flags
|= MS_ACTIVE
;
1168 mutex_unlock(&nilfs
->ns_mount_mutex
);
1171 close_bdev_exclusive(sd
.bdev
, mode
);
1172 simple_set_mnt(mnt
, s
);
1176 mutex_unlock(&nilfs
->ns_mount_mutex
);
1179 close_bdev_exclusive(sd
.bdev
, mode
);
1184 /* Abandoning the newly allocated superblock */
1185 mutex_unlock(&nilfs
->ns_mount_mutex
);
1187 deactivate_locked_super(s
);
1189 * deactivate_locked_super() invokes close_bdev_exclusive().
1190 * We must finish all post-cleaning before this call;
1191 * put_nilfs() needs the block device.
1196 struct file_system_type nilfs_fs_type
= {
1197 .owner
= THIS_MODULE
,
1199 .get_sb
= nilfs_get_sb
,
1200 .kill_sb
= kill_block_super
,
1201 .fs_flags
= FS_REQUIRES_DEV
,
1204 static void nilfs_inode_init_once(void *obj
)
1206 struct nilfs_inode_info
*ii
= obj
;
1208 INIT_LIST_HEAD(&ii
->i_dirty
);
1209 #ifdef CONFIG_NILFS_XATTR
1210 init_rwsem(&ii
->xattr_sem
);
1212 nilfs_btnode_cache_init_once(&ii
->i_btnode_cache
);
1213 ii
->i_bmap
= (struct nilfs_bmap
*)&ii
->i_bmap_union
;
1214 inode_init_once(&ii
->vfs_inode
);
1217 static void nilfs_segbuf_init_once(void *obj
)
1219 memset(obj
, 0, sizeof(struct nilfs_segment_buffer
));
1222 static void nilfs_destroy_cachep(void)
1224 if (nilfs_inode_cachep
)
1225 kmem_cache_destroy(nilfs_inode_cachep
);
1226 if (nilfs_transaction_cachep
)
1227 kmem_cache_destroy(nilfs_transaction_cachep
);
1228 if (nilfs_segbuf_cachep
)
1229 kmem_cache_destroy(nilfs_segbuf_cachep
);
1230 if (nilfs_btree_path_cache
)
1231 kmem_cache_destroy(nilfs_btree_path_cache
);
1234 static int __init
nilfs_init_cachep(void)
1236 nilfs_inode_cachep
= kmem_cache_create("nilfs2_inode_cache",
1237 sizeof(struct nilfs_inode_info
), 0,
1238 SLAB_RECLAIM_ACCOUNT
, nilfs_inode_init_once
);
1239 if (!nilfs_inode_cachep
)
1242 nilfs_transaction_cachep
= kmem_cache_create("nilfs2_transaction_cache",
1243 sizeof(struct nilfs_transaction_info
), 0,
1244 SLAB_RECLAIM_ACCOUNT
, NULL
);
1245 if (!nilfs_transaction_cachep
)
1248 nilfs_segbuf_cachep
= kmem_cache_create("nilfs2_segbuf_cache",
1249 sizeof(struct nilfs_segment_buffer
), 0,
1250 SLAB_RECLAIM_ACCOUNT
, nilfs_segbuf_init_once
);
1251 if (!nilfs_segbuf_cachep
)
1254 nilfs_btree_path_cache
= kmem_cache_create("nilfs2_btree_path_cache",
1255 sizeof(struct nilfs_btree_path
) * NILFS_BTREE_LEVEL_MAX
,
1257 if (!nilfs_btree_path_cache
)
1263 nilfs_destroy_cachep();
1267 static int __init
init_nilfs_fs(void)
1271 err
= nilfs_init_cachep();
1275 err
= register_filesystem(&nilfs_fs_type
);
1279 printk(KERN_INFO
"NILFS version 2 loaded\n");
1283 nilfs_destroy_cachep();
1288 static void __exit
exit_nilfs_fs(void)
1290 nilfs_destroy_cachep();
1291 unregister_filesystem(&nilfs_fs_type
);
1294 module_init(init_nilfs_fs
)
1295 module_exit(exit_nilfs_fs
)