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>
63 MODULE_AUTHOR("NTT Corp.");
64 MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem "
66 MODULE_VERSION(NILFS_VERSION
);
67 MODULE_LICENSE("GPL");
69 static int nilfs_remount(struct super_block
*sb
, int *flags
, char *data
);
70 static int test_exclusive_mount(struct file_system_type
*fs_type
,
71 struct block_device
*bdev
, int flags
);
74 * nilfs_error() - report failure condition on a filesystem
76 * nilfs_error() sets an ERROR_FS flag on the superblock as well as
77 * reporting an error message. It should be called when NILFS detects
78 * incoherences or defects of meta data on disk. As for sustainable
79 * errors such as a single-shot I/O error, nilfs_warning() or the printk()
80 * function should be used instead.
82 * The segment constructor must not call this function because it can
85 void nilfs_error(struct super_block
*sb
, const char *function
,
88 struct nilfs_sb_info
*sbi
= NILFS_SB(sb
);
92 printk(KERN_CRIT
"NILFS error (device %s): %s: ", sb
->s_id
, function
);
97 if (!(sb
->s_flags
& MS_RDONLY
)) {
98 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
100 if (!nilfs_test_opt(sbi
, ERRORS_CONT
))
101 nilfs_detach_segment_constructor(sbi
);
103 down_write(&nilfs
->ns_sem
);
104 if (!(nilfs
->ns_mount_state
& NILFS_ERROR_FS
)) {
105 nilfs
->ns_mount_state
|= NILFS_ERROR_FS
;
106 nilfs
->ns_sbp
->s_state
|= cpu_to_le16(NILFS_ERROR_FS
);
107 nilfs_commit_super(sbi
);
109 up_write(&nilfs
->ns_sem
);
111 if (nilfs_test_opt(sbi
, ERRORS_RO
)) {
112 printk(KERN_CRIT
"Remounting filesystem read-only\n");
113 sb
->s_flags
|= MS_RDONLY
;
117 if (nilfs_test_opt(sbi
, ERRORS_PANIC
))
118 panic("NILFS (device %s): panic forced after error\n",
122 void nilfs_warning(struct super_block
*sb
, const char *function
,
123 const char *fmt
, ...)
128 printk(KERN_WARNING
"NILFS warning (device %s): %s: ",
135 static struct kmem_cache
*nilfs_inode_cachep
;
137 struct inode
*nilfs_alloc_inode(struct super_block
*sb
)
139 struct nilfs_inode_info
*ii
;
141 ii
= kmem_cache_alloc(nilfs_inode_cachep
, GFP_NOFS
);
146 ii
->vfs_inode
.i_version
= 1;
147 nilfs_btnode_cache_init(&ii
->i_btnode_cache
);
148 return &ii
->vfs_inode
;
151 void nilfs_destroy_inode(struct inode
*inode
)
153 kmem_cache_free(nilfs_inode_cachep
, NILFS_I(inode
));
156 static void init_once(void *obj
)
158 struct nilfs_inode_info
*ii
= obj
;
160 INIT_LIST_HEAD(&ii
->i_dirty
);
161 #ifdef CONFIG_NILFS_XATTR
162 init_rwsem(&ii
->xattr_sem
);
164 nilfs_btnode_cache_init_once(&ii
->i_btnode_cache
);
165 ii
->i_bmap
= (struct nilfs_bmap
*)&ii
->i_bmap_union
;
166 inode_init_once(&ii
->vfs_inode
);
169 static int nilfs_init_inode_cache(void)
171 nilfs_inode_cachep
= kmem_cache_create("nilfs2_inode_cache",
172 sizeof(struct nilfs_inode_info
),
173 0, SLAB_RECLAIM_ACCOUNT
,
176 return (nilfs_inode_cachep
== NULL
) ? -ENOMEM
: 0;
179 static inline void nilfs_destroy_inode_cache(void)
181 kmem_cache_destroy(nilfs_inode_cachep
);
184 static void nilfs_clear_inode(struct inode
*inode
)
186 struct nilfs_inode_info
*ii
= NILFS_I(inode
);
188 #ifdef CONFIG_NILFS_POSIX_ACL
189 if (ii
->i_acl
&& ii
->i_acl
!= NILFS_ACL_NOT_CACHED
) {
190 posix_acl_release(ii
->i_acl
);
191 ii
->i_acl
= NILFS_ACL_NOT_CACHED
;
193 if (ii
->i_default_acl
&& ii
->i_default_acl
!= NILFS_ACL_NOT_CACHED
) {
194 posix_acl_release(ii
->i_default_acl
);
195 ii
->i_default_acl
= NILFS_ACL_NOT_CACHED
;
199 * Free resources allocated in nilfs_read_inode(), here.
201 BUG_ON(!list_empty(&ii
->i_dirty
));
205 if (test_bit(NILFS_I_BMAP
, &ii
->i_state
))
206 nilfs_bmap_clear(ii
->i_bmap
);
208 nilfs_btnode_cache_clear(&ii
->i_btnode_cache
);
212 * nilfs_update_last_segment - change pointer to the latest segment
213 * @sbi: nilfs_sb_info
214 * @update_cno: flag whether to update checkpoint number.
216 * nilfs_update_last_segment() changes information in the super block
217 * after a partial segment is written out successfully. The super
218 * block is marked dirty. It will be written out at the next VFS sync
219 * operations such as sync_supers() and generic_shutdown_super().
221 void nilfs_update_last_segment(struct nilfs_sb_info
*sbi
, int update_cno
)
223 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
224 struct nilfs_super_block
*sbp
= nilfs
->ns_sbp
;
226 /* nilfs->sem must be locked by the caller. */
227 spin_lock(&nilfs
->ns_last_segment_lock
);
229 nilfs
->ns_last_cno
= nilfs
->ns_cno
++;
230 sbp
->s_last_seq
= cpu_to_le64(nilfs
->ns_last_seq
);
231 sbp
->s_last_pseg
= cpu_to_le64(nilfs
->ns_last_pseg
);
232 sbp
->s_last_cno
= cpu_to_le64(nilfs
->ns_last_cno
);
233 spin_unlock(&nilfs
->ns_last_segment_lock
);
235 sbi
->s_super
->s_dirt
= 1; /* must be set if delaying the call of
236 nilfs_commit_super() */
239 static int nilfs_sync_super(struct nilfs_sb_info
*sbi
)
241 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
243 int barrier_done
= 0;
245 if (nilfs_test_opt(sbi
, BARRIER
)) {
246 set_buffer_ordered(nilfs
->ns_sbh
);
250 set_buffer_dirty(nilfs
->ns_sbh
);
251 err
= sync_dirty_buffer(nilfs
->ns_sbh
);
252 if (err
== -EOPNOTSUPP
&& barrier_done
) {
253 nilfs_warning(sbi
->s_super
, __func__
,
254 "barrier-based sync failed. "
255 "disabling barriers\n");
256 nilfs_clear_opt(sbi
, BARRIER
);
258 clear_buffer_ordered(nilfs
->ns_sbh
);
263 "NILFS: unable to write superblock (err=%d)\n", err
);
265 nilfs_dispose_used_segments(nilfs
);
266 clear_nilfs_discontinued(nilfs
);
272 int nilfs_commit_super(struct nilfs_sb_info
*sbi
)
274 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
275 struct nilfs_super_block
*sbp
= nilfs
->ns_sbp
;
276 sector_t nfreeblocks
;
279 /* nilfs->sem must be locked by the caller. */
280 err
= nilfs_count_free_blocks(nilfs
, &nfreeblocks
);
282 printk(KERN_ERR
"NILFS: failed to count free blocks\n");
285 sbp
->s_free_blocks_count
= cpu_to_le64(nfreeblocks
);
286 sbp
->s_wtime
= cpu_to_le64(get_seconds());
288 sbp
->s_sum
= crc32_le(nilfs
->ns_crc_seed
, (unsigned char *)sbp
,
289 le16_to_cpu(sbp
->s_bytes
));
291 sbi
->s_super
->s_dirt
= 0;
292 return nilfs_sync_super(sbi
);
295 static void nilfs_put_super(struct super_block
*sb
)
297 struct nilfs_sb_info
*sbi
= NILFS_SB(sb
);
298 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
300 nilfs_detach_segment_constructor(sbi
);
302 if (!(sb
->s_flags
& MS_RDONLY
)) {
303 down_write(&nilfs
->ns_sem
);
304 nilfs
->ns_sbp
->s_state
= cpu_to_le16(nilfs
->ns_mount_state
);
305 nilfs_commit_super(sbi
);
306 up_write(&nilfs
->ns_sem
);
309 nilfs_detach_checkpoint(sbi
);
310 put_nilfs(sbi
->s_nilfs
);
312 sb
->s_fs_info
= NULL
;
317 * nilfs_write_super - write super block(s) of NILFS
320 * nilfs_write_super() gets a fs-dependent lock, writes super block(s), and
321 * clears s_dirt. This function is called in the section protected by
324 * The s_dirt flag is managed by each filesystem and we protect it by ns_sem
325 * of the struct the_nilfs. Lock order must be as follows:
328 * 2. down_write(&nilfs->ns_sem)
330 * Inside NILFS, locking ns_sem is enough to protect s_dirt and the buffer
331 * of the super block (nilfs->ns_sbp).
333 * In most cases, VFS functions call lock_super() before calling these
334 * methods. So we must be careful not to bring on deadlocks when using
335 * lock_super(); see generic_shutdown_super(), write_super(), and so on.
337 * Note that order of lock_kernel() and lock_super() depends on contexts
338 * of VFS. We should also note that lock_kernel() can be used in its
339 * protective section and only the outermost one has an effect.
341 static void nilfs_write_super(struct super_block
*sb
)
343 struct nilfs_sb_info
*sbi
= NILFS_SB(sb
);
344 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
346 down_write(&nilfs
->ns_sem
);
347 if (!(sb
->s_flags
& MS_RDONLY
))
348 nilfs_commit_super(sbi
);
350 up_write(&nilfs
->ns_sem
);
353 static int nilfs_sync_fs(struct super_block
*sb
, int wait
)
357 /* This function is called when super block should be written back */
359 err
= nilfs_construct_segment(sb
);
363 int nilfs_attach_checkpoint(struct nilfs_sb_info
*sbi
, __u64 cno
)
365 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
366 struct nilfs_checkpoint
*raw_cp
;
367 struct buffer_head
*bh_cp
;
370 down_write(&nilfs
->ns_sem
);
371 list_add(&sbi
->s_list
, &nilfs
->ns_supers
);
372 up_write(&nilfs
->ns_sem
);
374 sbi
->s_ifile
= nilfs_mdt_new(
375 nilfs
, sbi
->s_super
, NILFS_IFILE_INO
, NILFS_IFILE_GFP
);
379 err
= nilfs_palloc_init_blockgroup(sbi
->s_ifile
, nilfs
->ns_inode_size
);
383 err
= nilfs_cpfile_get_checkpoint(nilfs
->ns_cpfile
, cno
, 0, &raw_cp
,
386 if (err
== -ENOENT
|| err
== -EINVAL
) {
388 "NILFS: Invalid checkpoint "
389 "(checkpoint number=%llu)\n",
390 (unsigned long long)cno
);
395 err
= nilfs_read_inode_common(sbi
->s_ifile
, &raw_cp
->cp_ifile_inode
);
398 atomic_set(&sbi
->s_inodes_count
, le64_to_cpu(raw_cp
->cp_inodes_count
));
399 atomic_set(&sbi
->s_blocks_count
, le64_to_cpu(raw_cp
->cp_blocks_count
));
401 nilfs_cpfile_put_checkpoint(nilfs
->ns_cpfile
, cno
, bh_cp
);
405 nilfs_cpfile_put_checkpoint(nilfs
->ns_cpfile
, cno
, bh_cp
);
407 nilfs_mdt_destroy(sbi
->s_ifile
);
410 down_write(&nilfs
->ns_sem
);
411 list_del_init(&sbi
->s_list
);
412 up_write(&nilfs
->ns_sem
);
417 void nilfs_detach_checkpoint(struct nilfs_sb_info
*sbi
)
419 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
421 nilfs_mdt_clear(sbi
->s_ifile
);
422 nilfs_mdt_destroy(sbi
->s_ifile
);
424 down_write(&nilfs
->ns_sem
);
425 list_del_init(&sbi
->s_list
);
426 up_write(&nilfs
->ns_sem
);
429 static int nilfs_mark_recovery_complete(struct nilfs_sb_info
*sbi
)
431 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
434 down_write(&nilfs
->ns_sem
);
435 if (!(nilfs
->ns_mount_state
& NILFS_VALID_FS
)) {
436 nilfs
->ns_mount_state
|= NILFS_VALID_FS
;
437 err
= nilfs_commit_super(sbi
);
439 printk(KERN_INFO
"NILFS: recovery complete.\n");
441 up_write(&nilfs
->ns_sem
);
445 static int nilfs_statfs(struct dentry
*dentry
, struct kstatfs
*buf
)
447 struct super_block
*sb
= dentry
->d_sb
;
448 struct nilfs_sb_info
*sbi
= NILFS_SB(sb
);
449 unsigned long long blocks
;
450 unsigned long overhead
;
451 unsigned long nrsvblocks
;
452 sector_t nfreeblocks
;
453 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
457 * Compute all of the segment blocks
459 * The blocks before first segment and after last segment
462 blocks
= nilfs
->ns_blocks_per_segment
* nilfs
->ns_nsegments
463 - nilfs
->ns_first_data_block
;
464 nrsvblocks
= nilfs
->ns_nrsvsegs
* nilfs
->ns_blocks_per_segment
;
467 * Compute the overhead
469 * When distributing meta data blocks outside semgent structure,
470 * We must count them as the overhead.
474 err
= nilfs_count_free_blocks(nilfs
, &nfreeblocks
);
478 buf
->f_type
= NILFS_SUPER_MAGIC
;
479 buf
->f_bsize
= sb
->s_blocksize
;
480 buf
->f_blocks
= blocks
- overhead
;
481 buf
->f_bfree
= nfreeblocks
;
482 buf
->f_bavail
= (buf
->f_bfree
>= nrsvblocks
) ?
483 (buf
->f_bfree
- nrsvblocks
) : 0;
484 buf
->f_files
= atomic_read(&sbi
->s_inodes_count
);
485 buf
->f_ffree
= 0; /* nilfs_count_free_inodes(sb); */
486 buf
->f_namelen
= NILFS_NAME_LEN
;
490 static struct super_operations nilfs_sops
= {
491 .alloc_inode
= nilfs_alloc_inode
,
492 .destroy_inode
= nilfs_destroy_inode
,
493 .dirty_inode
= nilfs_dirty_inode
,
494 /* .write_inode = nilfs_write_inode, */
495 /* .put_inode = nilfs_put_inode, */
496 /* .drop_inode = nilfs_drop_inode, */
497 .delete_inode
= nilfs_delete_inode
,
498 .put_super
= nilfs_put_super
,
499 .write_super
= nilfs_write_super
,
500 .sync_fs
= nilfs_sync_fs
,
501 /* .write_super_lockfs */
503 .statfs
= nilfs_statfs
,
504 .remount_fs
= nilfs_remount
,
505 .clear_inode
= nilfs_clear_inode
,
510 static struct inode
*
511 nilfs_nfs_get_inode(struct super_block
*sb
, u64 ino
, u32 generation
)
515 if (ino
< NILFS_FIRST_INO(sb
) && ino
!= NILFS_ROOT_INO
&&
516 ino
!= NILFS_SKETCH_INO
)
517 return ERR_PTR(-ESTALE
);
519 inode
= nilfs_iget(sb
, ino
);
521 return ERR_CAST(inode
);
522 if (generation
&& inode
->i_generation
!= generation
) {
524 return ERR_PTR(-ESTALE
);
530 static struct dentry
*
531 nilfs_fh_to_dentry(struct super_block
*sb
, struct fid
*fid
, int fh_len
,
534 return generic_fh_to_dentry(sb
, fid
, fh_len
, fh_type
,
535 nilfs_nfs_get_inode
);
538 static struct dentry
*
539 nilfs_fh_to_parent(struct super_block
*sb
, struct fid
*fid
, int fh_len
,
542 return generic_fh_to_parent(sb
, fid
, fh_len
, fh_type
,
543 nilfs_nfs_get_inode
);
546 static struct export_operations nilfs_export_ops
= {
547 .fh_to_dentry
= nilfs_fh_to_dentry
,
548 .fh_to_parent
= nilfs_fh_to_parent
,
549 .get_parent
= nilfs_get_parent
,
553 Opt_err_cont
, Opt_err_panic
, Opt_err_ro
,
554 Opt_barrier
, Opt_snapshot
, Opt_order
,
558 static match_table_t tokens
= {
559 {Opt_err_cont
, "errors=continue"},
560 {Opt_err_panic
, "errors=panic"},
561 {Opt_err_ro
, "errors=remount-ro"},
562 {Opt_barrier
, "barrier=%s"},
563 {Opt_snapshot
, "cp=%u"},
564 {Opt_order
, "order=%s"},
568 static int match_bool(substring_t
*s
, int *result
)
570 int len
= s
->to
- s
->from
;
572 if (strncmp(s
->from
, "on", len
) == 0)
574 else if (strncmp(s
->from
, "off", len
) == 0)
581 static int parse_options(char *options
, struct super_block
*sb
)
583 struct nilfs_sb_info
*sbi
= NILFS_SB(sb
);
585 substring_t args
[MAX_OPT_ARGS
];
591 while ((p
= strsep(&options
, ",")) != NULL
) {
596 token
= match_token(p
, tokens
, args
);
599 if (match_bool(&args
[0], &option
))
602 nilfs_set_opt(sbi
, BARRIER
);
604 nilfs_clear_opt(sbi
, BARRIER
);
607 if (strcmp(args
[0].from
, "relaxed") == 0)
608 /* Ordered data semantics */
609 nilfs_clear_opt(sbi
, STRICT_ORDER
);
610 else if (strcmp(args
[0].from
, "strict") == 0)
611 /* Strict in-order semantics */
612 nilfs_set_opt(sbi
, STRICT_ORDER
);
617 nilfs_write_opt(sbi
, ERROR_MODE
, ERRORS_PANIC
);
620 nilfs_write_opt(sbi
, ERROR_MODE
, ERRORS_RO
);
623 nilfs_write_opt(sbi
, ERROR_MODE
, ERRORS_CONT
);
626 if (match_int(&args
[0], &option
) || option
<= 0)
628 if (!(sb
->s_flags
& MS_RDONLY
))
630 sbi
->s_snapshot_cno
= option
;
631 nilfs_set_opt(sbi
, SNAPSHOT
);
635 "NILFS: Unrecognized mount option \"%s\"\n", p
);
643 nilfs_set_default_options(struct nilfs_sb_info
*sbi
,
644 struct nilfs_super_block
*sbp
)
647 NILFS_MOUNT_ERRORS_CONT
| NILFS_MOUNT_BARRIER
;
650 static int nilfs_setup_super(struct nilfs_sb_info
*sbi
)
652 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
653 struct nilfs_super_block
*sbp
= nilfs
->ns_sbp
;
654 int max_mnt_count
= le16_to_cpu(sbp
->s_max_mnt_count
);
655 int mnt_count
= le16_to_cpu(sbp
->s_mnt_count
);
657 /* nilfs->sem must be locked by the caller. */
658 if (!(nilfs
->ns_mount_state
& NILFS_VALID_FS
)) {
659 printk(KERN_WARNING
"NILFS warning: mounting unchecked fs\n");
660 } else if (nilfs
->ns_mount_state
& NILFS_ERROR_FS
) {
662 "NILFS warning: mounting fs with errors\n");
664 } else if (max_mnt_count
>= 0 && mnt_count
>= max_mnt_count
) {
666 "NILFS warning: maximal mount count reached\n");
670 sbp
->s_max_mnt_count
= cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT
);
672 sbp
->s_mnt_count
= cpu_to_le16(mnt_count
+ 1);
673 sbp
->s_state
= cpu_to_le16(le16_to_cpu(sbp
->s_state
) & ~NILFS_VALID_FS
);
674 sbp
->s_mtime
= cpu_to_le64(get_seconds());
675 return nilfs_commit_super(sbi
);
678 struct nilfs_super_block
*
679 nilfs_load_super_block(struct super_block
*sb
, struct buffer_head
**pbh
)
682 unsigned long offset
, sb_index
;
685 * Adjusting block size
686 * Blocksize will be enlarged when it is smaller than hardware
688 * Disk format of superblock does not change.
690 blocksize
= sb_min_blocksize(sb
, BLOCK_SIZE
);
693 "NILFS: unable to set blocksize of superblock\n");
696 sb_index
= NILFS_SB_OFFSET_BYTES
/ blocksize
;
697 offset
= NILFS_SB_OFFSET_BYTES
% blocksize
;
699 *pbh
= sb_bread(sb
, sb_index
);
701 printk(KERN_ERR
"NILFS: unable to read superblock\n");
704 return (struct nilfs_super_block
*)((char *)(*pbh
)->b_data
+ offset
);
707 struct nilfs_super_block
*
708 nilfs_reload_super_block(struct super_block
*sb
, struct buffer_head
**pbh
,
711 struct nilfs_super_block
*sbp
;
712 unsigned long offset
, sb_index
;
713 int hw_blocksize
= bdev_hardsect_size(sb
->s_bdev
);
715 if (blocksize
< hw_blocksize
) {
717 "NILFS: blocksize %d too small for device "
718 "(sector-size = %d).\n",
719 blocksize
, hw_blocksize
);
723 sb_set_blocksize(sb
, blocksize
);
725 sb_index
= NILFS_SB_OFFSET_BYTES
/ blocksize
;
726 offset
= NILFS_SB_OFFSET_BYTES
% blocksize
;
728 *pbh
= sb_bread(sb
, sb_index
);
731 "NILFS: cannot read superblock on 2nd try.\n");
735 sbp
= (struct nilfs_super_block
*)((char *)(*pbh
)->b_data
+ offset
);
736 if (sbp
->s_magic
!= cpu_to_le16(NILFS_SUPER_MAGIC
)) {
738 "NILFS: !? Magic mismatch on 2nd try.\n");
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 /* trying to fill super (1st stage) */
757 sb
->s_magic
= le16_to_cpu(sbp
->s_magic
);
759 /* FS independent flags */
760 #ifdef NILFS_ATIME_DISABLE
761 sb
->s_flags
|= MS_NOATIME
;
764 if (sb
->s_magic
!= NILFS_SUPER_MAGIC
) {
765 printk("NILFS: Can't find nilfs on dev %s.\n", sb
->s_id
);
769 nilfs_set_default_options(sbi
, sbp
);
771 sbi
->s_resuid
= le16_to_cpu(sbp
->s_def_resuid
);
772 sbi
->s_resgid
= le16_to_cpu(sbp
->s_def_resgid
);
773 sbi
->s_interval
= le32_to_cpu(sbp
->s_c_interval
);
774 sbi
->s_watermark
= le32_to_cpu(sbp
->s_c_block_max
);
776 if (!parse_options(data
, sb
))
783 * nilfs_fill_super() - initialize a super block instance
785 * @data: mount options
786 * @silent: silent mode flag
787 * @nilfs: the_nilfs struct
789 * This function is called exclusively by bd_mount_mutex.
790 * So, the recovery process is protected from other simultaneous mounts.
793 nilfs_fill_super(struct super_block
*sb
, void *data
, int silent
,
794 struct the_nilfs
*nilfs
)
796 struct nilfs_sb_info
*sbi
;
801 sbi
= kzalloc(sizeof(*sbi
), GFP_KERNEL
);
808 sbi
->s_nilfs
= nilfs
;
811 err
= init_nilfs(nilfs
, sbi
, (char *)data
);
815 spin_lock_init(&sbi
->s_inode_lock
);
816 INIT_LIST_HEAD(&sbi
->s_dirty_files
);
817 INIT_LIST_HEAD(&sbi
->s_list
);
820 * Following initialization is overlapped because
821 * nilfs_sb_info structure has been cleared at the beginning.
822 * But we reserve them to keep our interest and make ready
823 * for the future change.
825 get_random_bytes(&sbi
->s_next_generation
,
826 sizeof(sbi
->s_next_generation
));
827 spin_lock_init(&sbi
->s_next_gen_lock
);
829 sb
->s_op
= &nilfs_sops
;
830 sb
->s_export_op
= &nilfs_export_ops
;
833 if (!nilfs_loaded(nilfs
)) {
834 err
= load_nilfs(nilfs
, sbi
);
838 cno
= nilfs_last_cno(nilfs
);
840 if (sb
->s_flags
& MS_RDONLY
) {
841 if (nilfs_test_opt(sbi
, SNAPSHOT
)) {
842 if (!nilfs_cpfile_is_snapshot(nilfs
->ns_cpfile
,
843 sbi
->s_snapshot_cno
)) {
845 "NILFS: The specified checkpoint is "
847 "(checkpoint number=%llu).\n",
848 (unsigned long long)sbi
->s_snapshot_cno
);
852 cno
= sbi
->s_snapshot_cno
;
854 /* Read-only mount */
855 sbi
->s_snapshot_cno
= cno
;
858 err
= nilfs_attach_checkpoint(sbi
, cno
);
860 printk(KERN_ERR
"NILFS: error loading a checkpoint"
861 " (checkpoint number=%llu).\n", (unsigned long long)cno
);
865 if (!(sb
->s_flags
& MS_RDONLY
)) {
866 err
= nilfs_attach_segment_constructor(sbi
, NULL
);
868 goto failed_checkpoint
;
871 root
= nilfs_iget(sb
, NILFS_ROOT_INO
);
873 printk(KERN_ERR
"NILFS: get root inode failed\n");
877 if (!S_ISDIR(root
->i_mode
) || !root
->i_blocks
|| !root
->i_size
) {
879 printk(KERN_ERR
"NILFS: corrupt root inode.\n");
883 sb
->s_root
= d_alloc_root(root
);
886 printk(KERN_ERR
"NILFS: get root dentry failed\n");
891 if (!(sb
->s_flags
& MS_RDONLY
)) {
892 down_write(&nilfs
->ns_sem
);
893 nilfs_setup_super(sbi
);
894 up_write(&nilfs
->ns_sem
);
897 err
= nilfs_mark_recovery_complete(sbi
);
899 printk(KERN_ERR
"NILFS: recovery failed.\n");
910 nilfs_detach_segment_constructor(sbi
);
913 nilfs_detach_checkpoint(sbi
);
917 sb
->s_fs_info
= NULL
;
922 static int nilfs_remount(struct super_block
*sb
, int *flags
, char *data
)
924 struct nilfs_sb_info
*sbi
= NILFS_SB(sb
);
925 struct nilfs_super_block
*sbp
;
926 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
927 unsigned long old_sb_flags
;
928 struct nilfs_mount_options old_opts
;
931 old_sb_flags
= sb
->s_flags
;
932 old_opts
.mount_opt
= sbi
->s_mount_opt
;
933 old_opts
.snapshot_cno
= sbi
->s_snapshot_cno
;
935 if (!parse_options(data
, sb
)) {
939 sb
->s_flags
= (sb
->s_flags
& ~MS_POSIXACL
);
941 if ((*flags
& MS_RDONLY
) &&
942 sbi
->s_snapshot_cno
!= old_opts
.snapshot_cno
) {
943 printk(KERN_WARNING
"NILFS (device %s): couldn't "
944 "remount to a different snapshot. \n",
950 if ((*flags
& MS_RDONLY
) == (sb
->s_flags
& MS_RDONLY
))
952 if (*flags
& MS_RDONLY
) {
953 /* Shutting down the segment constructor */
954 nilfs_detach_segment_constructor(sbi
);
955 sb
->s_flags
|= MS_RDONLY
;
957 sbi
->s_snapshot_cno
= nilfs_last_cno(nilfs
);
958 /* nilfs_set_opt(sbi, SNAPSHOT); */
961 * Remounting a valid RW partition RDONLY, so set
962 * the RDONLY flag and then mark the partition as valid again.
964 down_write(&nilfs
->ns_sem
);
966 if (!(sbp
->s_state
& le16_to_cpu(NILFS_VALID_FS
)) &&
967 (nilfs
->ns_mount_state
& NILFS_VALID_FS
))
968 sbp
->s_state
= cpu_to_le16(nilfs
->ns_mount_state
);
969 sbp
->s_mtime
= cpu_to_le64(get_seconds());
970 nilfs_commit_super(sbi
);
971 up_write(&nilfs
->ns_sem
);
974 * Mounting a RDONLY partition read-write, so reread and
975 * store the current valid flag. (It may have been changed
976 * by fsck since we originally mounted the partition.)
978 down(&sb
->s_bdev
->bd_mount_sem
);
979 /* Check existing RW-mount */
980 if (test_exclusive_mount(sb
->s_type
, sb
->s_bdev
, 0)) {
981 printk(KERN_WARNING
"NILFS (device %s): couldn't "
982 "remount because a RW-mount exists.\n",
985 goto rw_remount_failed
;
987 if (sbi
->s_snapshot_cno
!= nilfs_last_cno(nilfs
)) {
988 printk(KERN_WARNING
"NILFS (device %s): couldn't "
989 "remount because the current RO-mount is not "
993 goto rw_remount_failed
;
995 sb
->s_flags
&= ~MS_RDONLY
;
996 nilfs_clear_opt(sbi
, SNAPSHOT
);
997 sbi
->s_snapshot_cno
= 0;
999 err
= nilfs_attach_segment_constructor(sbi
, NULL
);
1001 goto rw_remount_failed
;
1003 down_write(&nilfs
->ns_sem
);
1004 nilfs_setup_super(sbi
);
1005 up_write(&nilfs
->ns_sem
);
1007 up(&sb
->s_bdev
->bd_mount_sem
);
1013 up(&sb
->s_bdev
->bd_mount_sem
);
1015 sb
->s_flags
= old_sb_flags
;
1016 sbi
->s_mount_opt
= old_opts
.mount_opt
;
1017 sbi
->s_snapshot_cno
= old_opts
.snapshot_cno
;
1021 struct nilfs_super_data
{
1022 struct block_device
*bdev
;
1028 * nilfs_identify - pre-read mount options needed to identify mount instance
1029 * @data: mount options
1030 * @sd: nilfs_super_data
1032 static int nilfs_identify(char *data
, struct nilfs_super_data
*sd
)
1034 char *p
, *options
= data
;
1035 substring_t args
[MAX_OPT_ARGS
];
1040 p
= strsep(&options
, ",");
1041 if (p
!= NULL
&& *p
) {
1042 token
= match_token(p
, tokens
, args
);
1043 if (token
== Opt_snapshot
) {
1044 if (!(sd
->flags
& MS_RDONLY
))
1047 ret
= match_int(&args
[0], &option
);
1058 "NILFS: invalid mount option: %s\n", p
);
1062 BUG_ON(options
== data
);
1063 *(options
- 1) = ',';
1068 static int nilfs_set_bdev_super(struct super_block
*s
, void *data
)
1070 struct nilfs_super_data
*sd
= data
;
1072 s
->s_bdev
= sd
->bdev
;
1073 s
->s_dev
= s
->s_bdev
->bd_dev
;
1077 static int nilfs_test_bdev_super(struct super_block
*s
, void *data
)
1079 struct nilfs_super_data
*sd
= data
;
1081 return s
->s_bdev
== sd
->bdev
;
1084 static int nilfs_test_bdev_super2(struct super_block
*s
, void *data
)
1086 struct nilfs_super_data
*sd
= data
;
1089 if (s
->s_bdev
!= sd
->bdev
)
1092 if (!((s
->s_flags
| sd
->flags
) & MS_RDONLY
))
1093 return 1; /* Reuse an old R/W-mode super_block */
1095 if (s
->s_flags
& sd
->flags
& MS_RDONLY
) {
1096 if (down_read_trylock(&s
->s_umount
)) {
1098 (sd
->cno
== NILFS_SB(s
)->s_snapshot_cno
);
1099 up_read(&s
->s_umount
);
1101 * This path is locked with sb_lock by sget().
1102 * So, drop_super() causes deadlock.
1111 nilfs_get_sb(struct file_system_type
*fs_type
, int flags
,
1112 const char *dev_name
, void *data
, struct vfsmount
*mnt
)
1114 struct nilfs_super_data sd
;
1115 struct super_block
*s
, *s2
;
1116 struct the_nilfs
*nilfs
= NULL
;
1117 int err
, need_to_close
= 1;
1119 sd
.bdev
= open_bdev_exclusive(dev_name
, flags
, fs_type
);
1120 if (IS_ERR(sd
.bdev
))
1121 return PTR_ERR(sd
.bdev
);
1124 * To get mount instance using sget() vfs-routine, NILFS needs
1125 * much more information than normal filesystems to identify mount
1126 * instance. For snapshot mounts, not only a mount type (ro-mount
1127 * or rw-mount) but also a checkpoint number is required.
1128 * The results are passed in sget() using nilfs_super_data.
1132 if (nilfs_identify((char *)data
, &sd
)) {
1138 * once the super is inserted into the list by sget, s_umount
1139 * will protect the lockfs code from trying to start a snapshot
1140 * while we are mounting
1142 down(&sd
.bdev
->bd_mount_sem
);
1144 (err
= test_exclusive_mount(fs_type
, sd
.bdev
, flags
^ MS_RDONLY
))) {
1145 err
= (err
< 0) ? : -EBUSY
;
1150 * Phase-1: search any existent instance and get the_nilfs
1152 s
= sget(fs_type
, nilfs_test_bdev_super
, nilfs_set_bdev_super
, &sd
);
1158 nilfs
= alloc_nilfs(sd
.bdev
);
1162 struct nilfs_sb_info
*sbi
= NILFS_SB(s
);
1164 BUG_ON(!sbi
|| !sbi
->s_nilfs
);
1166 * s_umount protects super_block from unmount process;
1167 * It covers pointers of nilfs_sb_info and the_nilfs.
1169 nilfs
= sbi
->s_nilfs
;
1171 up_write(&s
->s_umount
);
1174 * Phase-2: search specified snapshot or R/W mode super_block
1177 /* trying to get the latest checkpoint. */
1178 sd
.cno
= nilfs_last_cno(nilfs
);
1180 s2
= sget(fs_type
, nilfs_test_bdev_super2
,
1181 nilfs_set_bdev_super
, &sd
);
1182 deactivate_super(s
);
1184 * Although deactivate_super() invokes close_bdev_exclusive() at
1185 * kill_block_super(). Here, s is an existent mount; we need
1186 * one more close_bdev_exclusive() call.
1194 char b
[BDEVNAME_SIZE
];
1197 strlcpy(s
->s_id
, bdevname(sd
.bdev
, b
), sizeof(s
->s_id
));
1198 sb_set_blocksize(s
, block_size(sd
.bdev
));
1200 err
= nilfs_fill_super(s
, data
, flags
& MS_VERBOSE
, nilfs
);
1204 s
->s_flags
|= MS_ACTIVE
;
1206 } else if (!(s
->s_flags
& MS_RDONLY
)) {
1210 up(&sd
.bdev
->bd_mount_sem
);
1213 close_bdev_exclusive(sd
.bdev
, flags
);
1214 simple_set_mnt(mnt
, s
);
1218 up(&sd
.bdev
->bd_mount_sem
);
1221 close_bdev_exclusive(sd
.bdev
, flags
);
1225 up(&sd
.bdev
->bd_mount_sem
);
1227 close_bdev_exclusive(sd
.bdev
, flags
);
1232 /* Abandoning the newly allocated superblock */
1233 up(&sd
.bdev
->bd_mount_sem
);
1236 up_write(&s
->s_umount
);
1237 deactivate_super(s
);
1239 * deactivate_super() invokes close_bdev_exclusive().
1240 * We must finish all post-cleaning before this call;
1241 * put_nilfs() and unlocking bd_mount_sem need the block device.
1246 static int nilfs_test_bdev_super3(struct super_block
*s
, void *data
)
1248 struct nilfs_super_data
*sd
= data
;
1251 if (s
->s_bdev
!= sd
->bdev
)
1253 if (down_read_trylock(&s
->s_umount
)) {
1254 ret
= (s
->s_flags
& MS_RDONLY
) && s
->s_root
&&
1255 nilfs_test_opt(NILFS_SB(s
), SNAPSHOT
);
1256 up_read(&s
->s_umount
);
1258 return 0; /* ignore snapshot mounts */
1260 return !((sd
->flags
^ s
->s_flags
) & MS_RDONLY
);
1263 static int __false_bdev_super(struct super_block
*s
, void *data
)
1265 #if 0 /* XXX: workaround for lock debug. This is not good idea */
1266 up_write(&s
->s_umount
);
1272 * test_exclusive_mount - check whether an exclusive RW/RO mount exists or not.
1273 * fs_type: filesystem type
1274 * bdev: block device
1275 * flag: 0 (check rw-mount) or MS_RDONLY (check ro-mount)
1276 * res: pointer to an integer to store result
1278 * This function must be called within a section protected by bd_mount_mutex.
1280 static int test_exclusive_mount(struct file_system_type
*fs_type
,
1281 struct block_device
*bdev
, int flags
)
1283 struct super_block
*s
;
1284 struct nilfs_super_data sd
= { .flags
= flags
, .bdev
= bdev
};
1286 s
= sget(fs_type
, nilfs_test_bdev_super3
, __false_bdev_super
, &sd
);
1288 if (PTR_ERR(s
) != -EFAULT
)
1290 return 0; /* Not found */
1292 up_write(&s
->s_umount
);
1293 deactivate_super(s
);
1294 return 1; /* Found */
1297 struct file_system_type nilfs_fs_type
= {
1298 .owner
= THIS_MODULE
,
1300 .get_sb
= nilfs_get_sb
,
1301 .kill_sb
= kill_block_super
,
1302 .fs_flags
= FS_REQUIRES_DEV
,
1305 static int __init
init_nilfs_fs(void)
1309 err
= nilfs_init_inode_cache();
1313 err
= nilfs_init_transaction_cache();
1315 goto failed_inode_cache
;
1317 err
= nilfs_init_segbuf_cache();
1319 goto failed_transaction_cache
;
1321 err
= nilfs_btree_path_cache_init();
1323 goto failed_segbuf_cache
;
1325 err
= register_filesystem(&nilfs_fs_type
);
1327 goto failed_btree_path_cache
;
1331 failed_btree_path_cache
:
1332 nilfs_btree_path_cache_destroy();
1334 failed_segbuf_cache
:
1335 nilfs_destroy_segbuf_cache();
1337 failed_transaction_cache
:
1338 nilfs_destroy_transaction_cache();
1341 nilfs_destroy_inode_cache();
1347 static void __exit
exit_nilfs_fs(void)
1349 nilfs_destroy_segbuf_cache();
1350 nilfs_destroy_transaction_cache();
1351 nilfs_destroy_inode_cache();
1352 nilfs_btree_path_cache_destroy();
1353 unregister_filesystem(&nilfs_fs_type
);
1356 module_init(init_nilfs_fs
)
1357 module_exit(exit_nilfs_fs
)