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
);
187 struct nilfs_transaction_info ti
;
188 struct nilfs_sb_info
*sbi
= NILFS_SB(inode
->i_sb
);
190 #ifdef CONFIG_NILFS_POSIX_ACL
191 if (ii
->i_acl
&& ii
->i_acl
!= NILFS_ACL_NOT_CACHED
) {
192 posix_acl_release(ii
->i_acl
);
193 ii
->i_acl
= NILFS_ACL_NOT_CACHED
;
195 if (ii
->i_default_acl
&& ii
->i_default_acl
!= NILFS_ACL_NOT_CACHED
) {
196 posix_acl_release(ii
->i_default_acl
);
197 ii
->i_default_acl
= NILFS_ACL_NOT_CACHED
;
201 * Free resources allocated in nilfs_read_inode(), here.
203 nilfs_transaction_begin(inode
->i_sb
, &ti
, 0);
205 spin_lock(&sbi
->s_inode_lock
);
206 if (!list_empty(&ii
->i_dirty
))
207 list_del_init(&ii
->i_dirty
);
210 spin_unlock(&sbi
->s_inode_lock
);
212 if (test_bit(NILFS_I_BMAP
, &ii
->i_state
))
213 nilfs_bmap_clear(ii
->i_bmap
);
215 nilfs_btnode_cache_clear(&ii
->i_btnode_cache
);
217 nilfs_transaction_end(inode
->i_sb
, 0);
221 * nilfs_update_last_segment - change pointer to the latest segment
222 * @sbi: nilfs_sb_info
223 * @update_cno: flag whether to update checkpoint number.
225 * nilfs_update_last_segment() changes information in the super block
226 * after a partial segment is written out successfully. The super
227 * block is marked dirty. It will be written out at the next VFS sync
228 * operations such as sync_supers() and generic_shutdown_super().
230 void nilfs_update_last_segment(struct nilfs_sb_info
*sbi
, int update_cno
)
232 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
233 struct nilfs_super_block
*sbp
= nilfs
->ns_sbp
;
235 /* nilfs->sem must be locked by the caller. */
236 spin_lock(&nilfs
->ns_last_segment_lock
);
238 nilfs
->ns_last_cno
= nilfs
->ns_cno
++;
239 sbp
->s_last_seq
= cpu_to_le64(nilfs
->ns_last_seq
);
240 sbp
->s_last_pseg
= cpu_to_le64(nilfs
->ns_last_pseg
);
241 sbp
->s_last_cno
= cpu_to_le64(nilfs
->ns_last_cno
);
242 spin_unlock(&nilfs
->ns_last_segment_lock
);
244 sbi
->s_super
->s_dirt
= 1; /* must be set if delaying the call of
245 nilfs_commit_super() */
248 static int nilfs_sync_super(struct nilfs_sb_info
*sbi
)
250 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
252 int barrier_done
= 0;
254 if (nilfs_test_opt(sbi
, BARRIER
)) {
255 set_buffer_ordered(nilfs
->ns_sbh
);
259 set_buffer_dirty(nilfs
->ns_sbh
);
260 err
= sync_dirty_buffer(nilfs
->ns_sbh
);
261 if (err
== -EOPNOTSUPP
&& barrier_done
) {
262 nilfs_warning(sbi
->s_super
, __func__
,
263 "barrier-based sync failed. "
264 "disabling barriers\n");
265 nilfs_clear_opt(sbi
, BARRIER
);
267 clear_buffer_ordered(nilfs
->ns_sbh
);
272 "NILFS: unable to write superblock (err=%d)\n", err
);
274 nilfs_dispose_used_segments(nilfs
);
275 clear_nilfs_discontinued(nilfs
);
281 int nilfs_commit_super(struct nilfs_sb_info
*sbi
)
283 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
284 struct nilfs_super_block
*sbp
= nilfs
->ns_sbp
;
285 sector_t nfreeblocks
;
288 /* nilfs->sem must be locked by the caller. */
289 err
= nilfs_count_free_blocks(nilfs
, &nfreeblocks
);
291 printk(KERN_ERR
"NILFS: failed to count free blocks\n");
294 sbp
->s_free_blocks_count
= cpu_to_le64(nfreeblocks
);
295 sbp
->s_wtime
= cpu_to_le64(get_seconds());
297 sbp
->s_sum
= crc32_le(nilfs
->ns_crc_seed
, (unsigned char *)sbp
,
298 le16_to_cpu(sbp
->s_bytes
));
300 sbi
->s_super
->s_dirt
= 0;
301 return nilfs_sync_super(sbi
);
304 static void nilfs_put_super(struct super_block
*sb
)
306 struct nilfs_sb_info
*sbi
= NILFS_SB(sb
);
307 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
309 nilfs_detach_segment_constructor(sbi
);
311 if (!(sb
->s_flags
& MS_RDONLY
)) {
312 down_write(&nilfs
->ns_sem
);
313 nilfs
->ns_sbp
->s_state
= cpu_to_le16(nilfs
->ns_mount_state
);
314 nilfs_commit_super(sbi
);
315 up_write(&nilfs
->ns_sem
);
318 nilfs_detach_checkpoint(sbi
);
319 put_nilfs(sbi
->s_nilfs
);
321 sb
->s_fs_info
= NULL
;
326 * nilfs_write_super - write super block(s) of NILFS
329 * nilfs_write_super() gets a fs-dependent lock, writes super block(s), and
330 * clears s_dirt. This function is called in the section protected by
333 * The s_dirt flag is managed by each filesystem and we protect it by ns_sem
334 * of the struct the_nilfs. Lock order must be as follows:
337 * 2. down_write(&nilfs->ns_sem)
339 * Inside NILFS, locking ns_sem is enough to protect s_dirt and the buffer
340 * of the super block (nilfs->ns_sbp).
342 * In most cases, VFS functions call lock_super() before calling these
343 * methods. So we must be careful not to bring on deadlocks when using
344 * lock_super(); see generic_shutdown_super(), write_super(), and so on.
346 * Note that order of lock_kernel() and lock_super() depends on contexts
347 * of VFS. We should also note that lock_kernel() can be used in its
348 * protective section and only the outermost one has an effect.
350 static void nilfs_write_super(struct super_block
*sb
)
352 struct nilfs_sb_info
*sbi
= NILFS_SB(sb
);
353 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
355 down_write(&nilfs
->ns_sem
);
356 if (!(sb
->s_flags
& MS_RDONLY
))
357 nilfs_commit_super(sbi
);
359 up_write(&nilfs
->ns_sem
);
362 static int nilfs_sync_fs(struct super_block
*sb
, int wait
)
366 /* This function is called when super block should be written back */
368 err
= nilfs_construct_segment(sb
);
372 int nilfs_attach_checkpoint(struct nilfs_sb_info
*sbi
, __u64 cno
)
374 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
375 struct nilfs_checkpoint
*raw_cp
;
376 struct buffer_head
*bh_cp
;
379 down_write(&nilfs
->ns_sem
);
380 list_add(&sbi
->s_list
, &nilfs
->ns_supers
);
381 up_write(&nilfs
->ns_sem
);
383 sbi
->s_ifile
= nilfs_mdt_new(
384 nilfs
, sbi
->s_super
, NILFS_IFILE_INO
, NILFS_IFILE_GFP
);
388 err
= nilfs_palloc_init_blockgroup(sbi
->s_ifile
, nilfs
->ns_inode_size
);
392 err
= nilfs_cpfile_get_checkpoint(nilfs
->ns_cpfile
, cno
, 0, &raw_cp
,
395 if (err
== -ENOENT
|| err
== -EINVAL
) {
397 "NILFS: Invalid checkpoint "
398 "(checkpoint number=%llu)\n",
399 (unsigned long long)cno
);
404 err
= nilfs_read_inode_common(sbi
->s_ifile
, &raw_cp
->cp_ifile_inode
);
407 atomic_set(&sbi
->s_inodes_count
, le64_to_cpu(raw_cp
->cp_inodes_count
));
408 atomic_set(&sbi
->s_blocks_count
, le64_to_cpu(raw_cp
->cp_blocks_count
));
410 nilfs_cpfile_put_checkpoint(nilfs
->ns_cpfile
, cno
, bh_cp
);
414 nilfs_cpfile_put_checkpoint(nilfs
->ns_cpfile
, cno
, bh_cp
);
416 nilfs_mdt_destroy(sbi
->s_ifile
);
419 down_write(&nilfs
->ns_sem
);
420 list_del_init(&sbi
->s_list
);
421 up_write(&nilfs
->ns_sem
);
426 void nilfs_detach_checkpoint(struct nilfs_sb_info
*sbi
)
428 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
430 nilfs_mdt_clear(sbi
->s_ifile
);
431 nilfs_mdt_destroy(sbi
->s_ifile
);
433 down_write(&nilfs
->ns_sem
);
434 list_del_init(&sbi
->s_list
);
435 up_write(&nilfs
->ns_sem
);
438 static int nilfs_mark_recovery_complete(struct nilfs_sb_info
*sbi
)
440 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
443 down_write(&nilfs
->ns_sem
);
444 if (!(nilfs
->ns_mount_state
& NILFS_VALID_FS
)) {
445 nilfs
->ns_mount_state
|= NILFS_VALID_FS
;
446 err
= nilfs_commit_super(sbi
);
448 printk(KERN_INFO
"NILFS: recovery complete.\n");
450 up_write(&nilfs
->ns_sem
);
454 static int nilfs_statfs(struct dentry
*dentry
, struct kstatfs
*buf
)
456 struct super_block
*sb
= dentry
->d_sb
;
457 struct nilfs_sb_info
*sbi
= NILFS_SB(sb
);
458 unsigned long long blocks
;
459 unsigned long overhead
;
460 unsigned long nrsvblocks
;
461 sector_t nfreeblocks
;
462 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
466 * Compute all of the segment blocks
468 * The blocks before first segment and after last segment
471 blocks
= nilfs
->ns_blocks_per_segment
* nilfs
->ns_nsegments
472 - nilfs
->ns_first_data_block
;
473 nrsvblocks
= nilfs
->ns_nrsvsegs
* nilfs
->ns_blocks_per_segment
;
476 * Compute the overhead
478 * When distributing meta data blocks outside semgent structure,
479 * We must count them as the overhead.
483 err
= nilfs_count_free_blocks(nilfs
, &nfreeblocks
);
487 buf
->f_type
= NILFS_SUPER_MAGIC
;
488 buf
->f_bsize
= sb
->s_blocksize
;
489 buf
->f_blocks
= blocks
- overhead
;
490 buf
->f_bfree
= nfreeblocks
;
491 buf
->f_bavail
= (buf
->f_bfree
>= nrsvblocks
) ?
492 (buf
->f_bfree
- nrsvblocks
) : 0;
493 buf
->f_files
= atomic_read(&sbi
->s_inodes_count
);
494 buf
->f_ffree
= 0; /* nilfs_count_free_inodes(sb); */
495 buf
->f_namelen
= NILFS_NAME_LEN
;
499 static struct super_operations nilfs_sops
= {
500 .alloc_inode
= nilfs_alloc_inode
,
501 .destroy_inode
= nilfs_destroy_inode
,
502 .dirty_inode
= nilfs_dirty_inode
,
503 /* .write_inode = nilfs_write_inode, */
504 /* .put_inode = nilfs_put_inode, */
505 /* .drop_inode = nilfs_drop_inode, */
506 .delete_inode
= nilfs_delete_inode
,
507 .put_super
= nilfs_put_super
,
508 .write_super
= nilfs_write_super
,
509 .sync_fs
= nilfs_sync_fs
,
510 /* .write_super_lockfs */
512 .statfs
= nilfs_statfs
,
513 .remount_fs
= nilfs_remount
,
514 .clear_inode
= nilfs_clear_inode
,
519 static struct inode
*
520 nilfs_nfs_get_inode(struct super_block
*sb
, u64 ino
, u32 generation
)
524 if (ino
< NILFS_FIRST_INO(sb
) && ino
!= NILFS_ROOT_INO
&&
525 ino
!= NILFS_SKETCH_INO
)
526 return ERR_PTR(-ESTALE
);
528 inode
= nilfs_iget(sb
, ino
);
530 return ERR_CAST(inode
);
531 if (generation
&& inode
->i_generation
!= generation
) {
533 return ERR_PTR(-ESTALE
);
539 static struct dentry
*
540 nilfs_fh_to_dentry(struct super_block
*sb
, struct fid
*fid
, int fh_len
,
543 return generic_fh_to_dentry(sb
, fid
, fh_len
, fh_type
,
544 nilfs_nfs_get_inode
);
547 static struct dentry
*
548 nilfs_fh_to_parent(struct super_block
*sb
, struct fid
*fid
, int fh_len
,
551 return generic_fh_to_parent(sb
, fid
, fh_len
, fh_type
,
552 nilfs_nfs_get_inode
);
555 static struct export_operations nilfs_export_ops
= {
556 .fh_to_dentry
= nilfs_fh_to_dentry
,
557 .fh_to_parent
= nilfs_fh_to_parent
,
558 .get_parent
= nilfs_get_parent
,
562 Opt_err_cont
, Opt_err_panic
, Opt_err_ro
,
563 Opt_barrier
, Opt_snapshot
, Opt_order
,
567 static match_table_t tokens
= {
568 {Opt_err_cont
, "errors=continue"},
569 {Opt_err_panic
, "errors=panic"},
570 {Opt_err_ro
, "errors=remount-ro"},
571 {Opt_barrier
, "barrier=%s"},
572 {Opt_snapshot
, "cp=%u"},
573 {Opt_order
, "order=%s"},
577 static int match_bool(substring_t
*s
, int *result
)
579 int len
= s
->to
- s
->from
;
581 if (strncmp(s
->from
, "on", len
) == 0)
583 else if (strncmp(s
->from
, "off", len
) == 0)
590 static int parse_options(char *options
, struct super_block
*sb
)
592 struct nilfs_sb_info
*sbi
= NILFS_SB(sb
);
594 substring_t args
[MAX_OPT_ARGS
];
600 while ((p
= strsep(&options
, ",")) != NULL
) {
605 token
= match_token(p
, tokens
, args
);
608 if (match_bool(&args
[0], &option
))
611 nilfs_set_opt(sbi
, BARRIER
);
613 nilfs_clear_opt(sbi
, BARRIER
);
616 if (strcmp(args
[0].from
, "relaxed") == 0)
617 /* Ordered data semantics */
618 nilfs_clear_opt(sbi
, STRICT_ORDER
);
619 else if (strcmp(args
[0].from
, "strict") == 0)
620 /* Strict in-order semantics */
621 nilfs_set_opt(sbi
, STRICT_ORDER
);
626 nilfs_write_opt(sbi
, ERROR_MODE
, ERRORS_PANIC
);
629 nilfs_write_opt(sbi
, ERROR_MODE
, ERRORS_RO
);
632 nilfs_write_opt(sbi
, ERROR_MODE
, ERRORS_CONT
);
635 if (match_int(&args
[0], &option
) || option
<= 0)
637 if (!(sb
->s_flags
& MS_RDONLY
))
639 sbi
->s_snapshot_cno
= option
;
640 nilfs_set_opt(sbi
, SNAPSHOT
);
644 "NILFS: Unrecognized mount option \"%s\"\n", p
);
652 nilfs_set_default_options(struct nilfs_sb_info
*sbi
,
653 struct nilfs_super_block
*sbp
)
656 NILFS_MOUNT_ERRORS_CONT
| NILFS_MOUNT_BARRIER
;
659 static int nilfs_setup_super(struct nilfs_sb_info
*sbi
)
661 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
662 struct nilfs_super_block
*sbp
= nilfs
->ns_sbp
;
663 int max_mnt_count
= le16_to_cpu(sbp
->s_max_mnt_count
);
664 int mnt_count
= le16_to_cpu(sbp
->s_mnt_count
);
666 /* nilfs->sem must be locked by the caller. */
667 if (!(nilfs
->ns_mount_state
& NILFS_VALID_FS
)) {
668 printk(KERN_WARNING
"NILFS warning: mounting unchecked fs\n");
669 } else if (nilfs
->ns_mount_state
& NILFS_ERROR_FS
) {
671 "NILFS warning: mounting fs with errors\n");
673 } else if (max_mnt_count
>= 0 && mnt_count
>= max_mnt_count
) {
675 "NILFS warning: maximal mount count reached\n");
679 sbp
->s_max_mnt_count
= cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT
);
681 sbp
->s_mnt_count
= cpu_to_le16(mnt_count
+ 1);
682 sbp
->s_state
= cpu_to_le16(le16_to_cpu(sbp
->s_state
) & ~NILFS_VALID_FS
);
683 sbp
->s_mtime
= cpu_to_le64(get_seconds());
684 return nilfs_commit_super(sbi
);
687 struct nilfs_super_block
*
688 nilfs_load_super_block(struct super_block
*sb
, struct buffer_head
**pbh
)
691 unsigned long offset
, sb_index
;
694 * Adjusting block size
695 * Blocksize will be enlarged when it is smaller than hardware
697 * Disk format of superblock does not change.
699 blocksize
= sb_min_blocksize(sb
, BLOCK_SIZE
);
702 "NILFS: unable to set blocksize of superblock\n");
705 sb_index
= NILFS_SB_OFFSET_BYTES
/ blocksize
;
706 offset
= NILFS_SB_OFFSET_BYTES
% blocksize
;
708 *pbh
= sb_bread(sb
, sb_index
);
710 printk(KERN_ERR
"NILFS: unable to read superblock\n");
713 return (struct nilfs_super_block
*)((char *)(*pbh
)->b_data
+ offset
);
716 struct nilfs_super_block
*
717 nilfs_reload_super_block(struct super_block
*sb
, struct buffer_head
**pbh
,
720 struct nilfs_super_block
*sbp
;
721 unsigned long offset
, sb_index
;
722 int hw_blocksize
= bdev_hardsect_size(sb
->s_bdev
);
724 if (blocksize
< hw_blocksize
) {
726 "NILFS: blocksize %d too small for device "
727 "(sector-size = %d).\n",
728 blocksize
, hw_blocksize
);
732 sb_set_blocksize(sb
, blocksize
);
734 sb_index
= NILFS_SB_OFFSET_BYTES
/ blocksize
;
735 offset
= NILFS_SB_OFFSET_BYTES
% blocksize
;
737 *pbh
= sb_bread(sb
, sb_index
);
740 "NILFS: cannot read superblock on 2nd try.\n");
744 sbp
= (struct nilfs_super_block
*)((char *)(*pbh
)->b_data
+ offset
);
745 if (sbp
->s_magic
!= cpu_to_le16(NILFS_SUPER_MAGIC
)) {
747 "NILFS: !? Magic mismatch on 2nd try.\n");
759 int nilfs_store_magic_and_option(struct super_block
*sb
,
760 struct nilfs_super_block
*sbp
,
763 struct nilfs_sb_info
*sbi
= NILFS_SB(sb
);
765 /* trying to fill super (1st stage) */
766 sb
->s_magic
= le16_to_cpu(sbp
->s_magic
);
768 /* FS independent flags */
769 #ifdef NILFS_ATIME_DISABLE
770 sb
->s_flags
|= MS_NOATIME
;
773 if (sb
->s_magic
!= NILFS_SUPER_MAGIC
) {
774 printk("NILFS: Can't find nilfs on dev %s.\n", sb
->s_id
);
778 nilfs_set_default_options(sbi
, sbp
);
780 sbi
->s_resuid
= le16_to_cpu(sbp
->s_def_resuid
);
781 sbi
->s_resgid
= le16_to_cpu(sbp
->s_def_resgid
);
782 sbi
->s_interval
= le32_to_cpu(sbp
->s_c_interval
);
783 sbi
->s_watermark
= le32_to_cpu(sbp
->s_c_block_max
);
785 if (!parse_options(data
, sb
))
792 * nilfs_fill_super() - initialize a super block instance
794 * @data: mount options
795 * @silent: silent mode flag
796 * @nilfs: the_nilfs struct
798 * This function is called exclusively by bd_mount_mutex.
799 * So, the recovery process is protected from other simultaneous mounts.
802 nilfs_fill_super(struct super_block
*sb
, void *data
, int silent
,
803 struct the_nilfs
*nilfs
)
805 struct nilfs_sb_info
*sbi
;
810 sbi
= kzalloc(sizeof(*sbi
), GFP_KERNEL
);
817 sbi
->s_nilfs
= nilfs
;
820 err
= init_nilfs(nilfs
, sbi
, (char *)data
);
824 spin_lock_init(&sbi
->s_inode_lock
);
825 INIT_LIST_HEAD(&sbi
->s_dirty_files
);
826 INIT_LIST_HEAD(&sbi
->s_list
);
829 * Following initialization is overlapped because
830 * nilfs_sb_info structure has been cleared at the beginning.
831 * But we reserve them to keep our interest and make ready
832 * for the future change.
834 get_random_bytes(&sbi
->s_next_generation
,
835 sizeof(sbi
->s_next_generation
));
836 spin_lock_init(&sbi
->s_next_gen_lock
);
838 sb
->s_op
= &nilfs_sops
;
839 sb
->s_export_op
= &nilfs_export_ops
;
842 if (!nilfs_loaded(nilfs
)) {
843 err
= load_nilfs(nilfs
, sbi
);
847 cno
= nilfs_last_cno(nilfs
);
849 if (sb
->s_flags
& MS_RDONLY
) {
850 if (nilfs_test_opt(sbi
, SNAPSHOT
)) {
851 if (!nilfs_cpfile_is_snapshot(nilfs
->ns_cpfile
,
852 sbi
->s_snapshot_cno
)) {
854 "NILFS: The specified checkpoint is "
856 "(checkpoint number=%llu).\n",
857 (unsigned long long)sbi
->s_snapshot_cno
);
861 cno
= sbi
->s_snapshot_cno
;
863 /* Read-only mount */
864 sbi
->s_snapshot_cno
= cno
;
867 err
= nilfs_attach_checkpoint(sbi
, cno
);
869 printk(KERN_ERR
"NILFS: error loading a checkpoint"
870 " (checkpoint number=%llu).\n", (unsigned long long)cno
);
874 if (!(sb
->s_flags
& MS_RDONLY
)) {
875 err
= nilfs_attach_segment_constructor(sbi
, NULL
);
877 goto failed_checkpoint
;
880 root
= nilfs_iget(sb
, NILFS_ROOT_INO
);
882 printk(KERN_ERR
"NILFS: get root inode failed\n");
886 if (!S_ISDIR(root
->i_mode
) || !root
->i_blocks
|| !root
->i_size
) {
888 printk(KERN_ERR
"NILFS: corrupt root inode.\n");
892 sb
->s_root
= d_alloc_root(root
);
895 printk(KERN_ERR
"NILFS: get root dentry failed\n");
900 if (!(sb
->s_flags
& MS_RDONLY
)) {
901 down_write(&nilfs
->ns_sem
);
902 nilfs_setup_super(sbi
);
903 up_write(&nilfs
->ns_sem
);
906 err
= nilfs_mark_recovery_complete(sbi
);
908 printk(KERN_ERR
"NILFS: recovery failed.\n");
919 nilfs_detach_segment_constructor(sbi
);
922 nilfs_detach_checkpoint(sbi
);
926 sb
->s_fs_info
= NULL
;
931 static int nilfs_remount(struct super_block
*sb
, int *flags
, char *data
)
933 struct nilfs_sb_info
*sbi
= NILFS_SB(sb
);
934 struct nilfs_super_block
*sbp
;
935 struct the_nilfs
*nilfs
= sbi
->s_nilfs
;
936 unsigned long old_sb_flags
;
937 struct nilfs_mount_options old_opts
;
940 old_sb_flags
= sb
->s_flags
;
941 old_opts
.mount_opt
= sbi
->s_mount_opt
;
942 old_opts
.snapshot_cno
= sbi
->s_snapshot_cno
;
944 if (!parse_options(data
, sb
)) {
948 sb
->s_flags
= (sb
->s_flags
& ~MS_POSIXACL
);
950 if ((*flags
& MS_RDONLY
) &&
951 sbi
->s_snapshot_cno
!= old_opts
.snapshot_cno
) {
952 printk(KERN_WARNING
"NILFS (device %s): couldn't "
953 "remount to a different snapshot. \n",
959 if ((*flags
& MS_RDONLY
) == (sb
->s_flags
& MS_RDONLY
))
961 if (*flags
& MS_RDONLY
) {
962 /* Shutting down the segment constructor */
963 nilfs_detach_segment_constructor(sbi
);
964 sb
->s_flags
|= MS_RDONLY
;
966 sbi
->s_snapshot_cno
= nilfs_last_cno(nilfs
);
967 /* nilfs_set_opt(sbi, SNAPSHOT); */
970 * Remounting a valid RW partition RDONLY, so set
971 * the RDONLY flag and then mark the partition as valid again.
973 down_write(&nilfs
->ns_sem
);
975 if (!(sbp
->s_state
& le16_to_cpu(NILFS_VALID_FS
)) &&
976 (nilfs
->ns_mount_state
& NILFS_VALID_FS
))
977 sbp
->s_state
= cpu_to_le16(nilfs
->ns_mount_state
);
978 sbp
->s_mtime
= cpu_to_le64(get_seconds());
979 nilfs_commit_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 down(&sb
->s_bdev
->bd_mount_sem
);
988 /* Check existing RW-mount */
989 if (test_exclusive_mount(sb
->s_type
, sb
->s_bdev
, 0)) {
990 printk(KERN_WARNING
"NILFS (device %s): couldn't "
991 "remount because a RW-mount exists.\n",
994 goto rw_remount_failed
;
996 if (sbi
->s_snapshot_cno
!= nilfs_last_cno(nilfs
)) {
997 printk(KERN_WARNING
"NILFS (device %s): couldn't "
998 "remount because the current RO-mount is not "
1002 goto rw_remount_failed
;
1004 sb
->s_flags
&= ~MS_RDONLY
;
1005 nilfs_clear_opt(sbi
, SNAPSHOT
);
1006 sbi
->s_snapshot_cno
= 0;
1008 err
= nilfs_attach_segment_constructor(sbi
, NULL
);
1010 goto rw_remount_failed
;
1012 down_write(&nilfs
->ns_sem
);
1013 nilfs_setup_super(sbi
);
1014 up_write(&nilfs
->ns_sem
);
1016 up(&sb
->s_bdev
->bd_mount_sem
);
1022 up(&sb
->s_bdev
->bd_mount_sem
);
1024 sb
->s_flags
= old_sb_flags
;
1025 sbi
->s_mount_opt
= old_opts
.mount_opt
;
1026 sbi
->s_snapshot_cno
= old_opts
.snapshot_cno
;
1030 struct nilfs_super_data
{
1031 struct block_device
*bdev
;
1037 * nilfs_identify - pre-read mount options needed to identify mount instance
1038 * @data: mount options
1039 * @sd: nilfs_super_data
1041 static int nilfs_identify(char *data
, struct nilfs_super_data
*sd
)
1043 char *p
, *options
= data
;
1044 substring_t args
[MAX_OPT_ARGS
];
1049 p
= strsep(&options
, ",");
1050 if (p
!= NULL
&& *p
) {
1051 token
= match_token(p
, tokens
, args
);
1052 if (token
== Opt_snapshot
) {
1053 if (!(sd
->flags
& MS_RDONLY
))
1056 ret
= match_int(&args
[0], &option
);
1067 "NILFS: invalid mount option: %s\n", p
);
1071 BUG_ON(options
== data
);
1072 *(options
- 1) = ',';
1077 static int nilfs_set_bdev_super(struct super_block
*s
, void *data
)
1079 struct nilfs_super_data
*sd
= data
;
1081 s
->s_bdev
= sd
->bdev
;
1082 s
->s_dev
= s
->s_bdev
->bd_dev
;
1086 static int nilfs_test_bdev_super(struct super_block
*s
, void *data
)
1088 struct nilfs_super_data
*sd
= data
;
1090 return s
->s_bdev
== sd
->bdev
;
1093 static int nilfs_test_bdev_super2(struct super_block
*s
, void *data
)
1095 struct nilfs_super_data
*sd
= data
;
1098 if (s
->s_bdev
!= sd
->bdev
)
1101 if (!((s
->s_flags
| sd
->flags
) & MS_RDONLY
))
1102 return 1; /* Reuse an old R/W-mode super_block */
1104 if (s
->s_flags
& sd
->flags
& MS_RDONLY
) {
1105 if (down_read_trylock(&s
->s_umount
)) {
1107 (sd
->cno
== NILFS_SB(s
)->s_snapshot_cno
);
1108 up_read(&s
->s_umount
);
1110 * This path is locked with sb_lock by sget().
1111 * So, drop_super() causes deadlock.
1120 nilfs_get_sb(struct file_system_type
*fs_type
, int flags
,
1121 const char *dev_name
, void *data
, struct vfsmount
*mnt
)
1123 struct nilfs_super_data sd
;
1124 struct super_block
*s
, *s2
;
1125 struct the_nilfs
*nilfs
= NULL
;
1126 int err
, need_to_close
= 1;
1128 sd
.bdev
= open_bdev_exclusive(dev_name
, flags
, fs_type
);
1129 if (IS_ERR(sd
.bdev
))
1130 return PTR_ERR(sd
.bdev
);
1133 * To get mount instance using sget() vfs-routine, NILFS needs
1134 * much more information than normal filesystems to identify mount
1135 * instance. For snapshot mounts, not only a mount type (ro-mount
1136 * or rw-mount) but also a checkpoint number is required.
1137 * The results are passed in sget() using nilfs_super_data.
1141 if (nilfs_identify((char *)data
, &sd
)) {
1147 * once the super is inserted into the list by sget, s_umount
1148 * will protect the lockfs code from trying to start a snapshot
1149 * while we are mounting
1151 down(&sd
.bdev
->bd_mount_sem
);
1153 (err
= test_exclusive_mount(fs_type
, sd
.bdev
, flags
^ MS_RDONLY
))) {
1154 err
= (err
< 0) ? : -EBUSY
;
1159 * Phase-1: search any existent instance and get the_nilfs
1161 s
= sget(fs_type
, nilfs_test_bdev_super
, nilfs_set_bdev_super
, &sd
);
1167 nilfs
= alloc_nilfs(sd
.bdev
);
1171 struct nilfs_sb_info
*sbi
= NILFS_SB(s
);
1173 BUG_ON(!sbi
|| !sbi
->s_nilfs
);
1175 * s_umount protects super_block from unmount process;
1176 * It covers pointers of nilfs_sb_info and the_nilfs.
1178 nilfs
= sbi
->s_nilfs
;
1180 up_write(&s
->s_umount
);
1183 * Phase-2: search specified snapshot or R/W mode super_block
1186 /* trying to get the latest checkpoint. */
1187 sd
.cno
= nilfs_last_cno(nilfs
);
1189 s2
= sget(fs_type
, nilfs_test_bdev_super2
,
1190 nilfs_set_bdev_super
, &sd
);
1191 deactivate_super(s
);
1193 * Although deactivate_super() invokes close_bdev_exclusive() at
1194 * kill_block_super(). Here, s is an existent mount; we need
1195 * one more close_bdev_exclusive() call.
1203 char b
[BDEVNAME_SIZE
];
1206 strlcpy(s
->s_id
, bdevname(sd
.bdev
, b
), sizeof(s
->s_id
));
1207 sb_set_blocksize(s
, block_size(sd
.bdev
));
1209 err
= nilfs_fill_super(s
, data
, flags
& MS_VERBOSE
, nilfs
);
1213 s
->s_flags
|= MS_ACTIVE
;
1215 } else if (!(s
->s_flags
& MS_RDONLY
)) {
1219 up(&sd
.bdev
->bd_mount_sem
);
1222 close_bdev_exclusive(sd
.bdev
, flags
);
1223 simple_set_mnt(mnt
, s
);
1227 up(&sd
.bdev
->bd_mount_sem
);
1230 close_bdev_exclusive(sd
.bdev
, flags
);
1234 up(&sd
.bdev
->bd_mount_sem
);
1236 close_bdev_exclusive(sd
.bdev
, flags
);
1241 /* Abandoning the newly allocated superblock */
1242 up(&sd
.bdev
->bd_mount_sem
);
1245 up_write(&s
->s_umount
);
1246 deactivate_super(s
);
1248 * deactivate_super() invokes close_bdev_exclusive().
1249 * We must finish all post-cleaning before this call;
1250 * put_nilfs() and unlocking bd_mount_sem need the block device.
1255 static int nilfs_test_bdev_super3(struct super_block
*s
, void *data
)
1257 struct nilfs_super_data
*sd
= data
;
1260 if (s
->s_bdev
!= sd
->bdev
)
1262 if (down_read_trylock(&s
->s_umount
)) {
1263 ret
= (s
->s_flags
& MS_RDONLY
) && s
->s_root
&&
1264 nilfs_test_opt(NILFS_SB(s
), SNAPSHOT
);
1265 up_read(&s
->s_umount
);
1267 return 0; /* ignore snapshot mounts */
1269 return !((sd
->flags
^ s
->s_flags
) & MS_RDONLY
);
1272 static int __false_bdev_super(struct super_block
*s
, void *data
)
1274 #if 0 /* XXX: workaround for lock debug. This is not good idea */
1275 up_write(&s
->s_umount
);
1281 * test_exclusive_mount - check whether an exclusive RW/RO mount exists or not.
1282 * fs_type: filesystem type
1283 * bdev: block device
1284 * flag: 0 (check rw-mount) or MS_RDONLY (check ro-mount)
1285 * res: pointer to an integer to store result
1287 * This function must be called within a section protected by bd_mount_mutex.
1289 static int test_exclusive_mount(struct file_system_type
*fs_type
,
1290 struct block_device
*bdev
, int flags
)
1292 struct super_block
*s
;
1293 struct nilfs_super_data sd
= { .flags
= flags
, .bdev
= bdev
};
1295 s
= sget(fs_type
, nilfs_test_bdev_super3
, __false_bdev_super
, &sd
);
1297 if (PTR_ERR(s
) != -EFAULT
)
1299 return 0; /* Not found */
1301 up_write(&s
->s_umount
);
1302 deactivate_super(s
);
1303 return 1; /* Found */
1306 struct file_system_type nilfs_fs_type
= {
1307 .owner
= THIS_MODULE
,
1309 .get_sb
= nilfs_get_sb
,
1310 .kill_sb
= kill_block_super
,
1311 .fs_flags
= FS_REQUIRES_DEV
,
1314 static int __init
init_nilfs_fs(void)
1318 err
= nilfs_init_inode_cache();
1322 err
= nilfs_init_transaction_cache();
1324 goto failed_inode_cache
;
1326 err
= nilfs_init_segbuf_cache();
1328 goto failed_transaction_cache
;
1330 err
= nilfs_btree_path_cache_init();
1332 goto failed_segbuf_cache
;
1334 err
= register_filesystem(&nilfs_fs_type
);
1336 goto failed_btree_path_cache
;
1340 failed_btree_path_cache
:
1341 nilfs_btree_path_cache_destroy();
1343 failed_segbuf_cache
:
1344 nilfs_destroy_segbuf_cache();
1346 failed_transaction_cache
:
1347 nilfs_destroy_transaction_cache();
1350 nilfs_destroy_inode_cache();
1356 static void __exit
exit_nilfs_fs(void)
1358 nilfs_destroy_segbuf_cache();
1359 nilfs_destroy_transaction_cache();
1360 nilfs_destroy_inode_cache();
1361 nilfs_btree_path_cache_destroy();
1362 unregister_filesystem(&nilfs_fs_type
);
1365 module_init(init_nilfs_fs
)
1366 module_exit(exit_nilfs_fs
)