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 static int nilfs_remount(struct super_block *sb, int *flags, char *data);
73 * nilfs_error() - report failure condition on a filesystem
75 * nilfs_error() sets an ERROR_FS flag on the superblock as well as
76 * reporting an error message. It should be called when NILFS detects
77 * incoherences or defects of meta data on disk. As for sustainable
78 * errors such as a single-shot I/O error, nilfs_warning() or the printk()
79 * function should be used instead.
81 * The segment constructor must not call this function because it can
84 void nilfs_error(struct super_block *sb, const char *function,
87 struct nilfs_sb_info *sbi = NILFS_SB(sb);
91 printk(KERN_CRIT "NILFS error (device %s): %s: ", sb->s_id, function);
96 if (!(sb->s_flags & MS_RDONLY)) {
97 struct the_nilfs *nilfs = sbi->s_nilfs;
99 if (!nilfs_test_opt(sbi, ERRORS_CONT))
100 nilfs_detach_segment_constructor(sbi);
102 down_write(&nilfs->ns_sem);
103 if (!(nilfs->ns_mount_state & NILFS_ERROR_FS)) {
104 nilfs->ns_mount_state |= NILFS_ERROR_FS;
105 nilfs->ns_sbp[0]->s_state |=
106 cpu_to_le16(NILFS_ERROR_FS);
107 nilfs_commit_super(sbi, 1);
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_common(struct the_nilfs *nilfs)
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, nilfs->ns_bdi);
148 return &ii->vfs_inode;
151 struct inode *nilfs_alloc_inode(struct super_block *sb)
153 return nilfs_alloc_inode_common(NILFS_SB(sb)->s_nilfs);
156 void nilfs_destroy_inode(struct inode *inode)
158 kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode));
161 static void init_once(void *obj)
163 struct nilfs_inode_info *ii = obj;
165 INIT_LIST_HEAD(&ii->i_dirty);
166 #ifdef CONFIG_NILFS_XATTR
167 init_rwsem(&ii->xattr_sem);
169 nilfs_btnode_cache_init_once(&ii->i_btnode_cache);
170 ii->i_bmap = (struct nilfs_bmap *)&ii->i_bmap_union;
171 inode_init_once(&ii->vfs_inode);
174 static int nilfs_init_inode_cache(void)
176 nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache",
177 sizeof(struct nilfs_inode_info),
178 0, SLAB_RECLAIM_ACCOUNT,
181 return (nilfs_inode_cachep == NULL) ? -ENOMEM : 0;
184 static inline void nilfs_destroy_inode_cache(void)
186 kmem_cache_destroy(nilfs_inode_cachep);
189 static void nilfs_clear_inode(struct inode *inode)
191 struct nilfs_inode_info *ii = NILFS_I(inode);
194 * Free resources allocated in nilfs_read_inode(), here.
196 BUG_ON(!list_empty(&ii->i_dirty));
200 if (test_bit(NILFS_I_BMAP, &ii->i_state))
201 nilfs_bmap_clear(ii->i_bmap);
203 nilfs_btnode_cache_clear(&ii->i_btnode_cache);
206 static int nilfs_sync_super(struct nilfs_sb_info *sbi, int dupsb)
208 struct the_nilfs *nilfs = sbi->s_nilfs;
210 int barrier_done = 0;
212 if (nilfs_test_opt(sbi, BARRIER)) {
213 set_buffer_ordered(nilfs->ns_sbh[0]);
217 set_buffer_dirty(nilfs->ns_sbh[0]);
218 err = sync_dirty_buffer(nilfs->ns_sbh[0]);
219 if (err == -EOPNOTSUPP && barrier_done) {
220 nilfs_warning(sbi->s_super, __func__,
221 "barrier-based sync failed. "
222 "disabling barriers\n");
223 nilfs_clear_opt(sbi, BARRIER);
225 clear_buffer_ordered(nilfs->ns_sbh[0]);
230 "NILFS: unable to write superblock (err=%d)\n", err);
231 if (err == -EIO && nilfs->ns_sbh[1]) {
232 nilfs_fall_back_super_block(nilfs);
236 struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
239 * The latest segment becomes trailable from the position
240 * written in superblock.
242 clear_nilfs_discontinued(nilfs);
244 /* update GC protection for recent segments */
245 if (nilfs->ns_sbh[1]) {
248 set_buffer_dirty(nilfs->ns_sbh[1]);
249 if (!sync_dirty_buffer(nilfs->ns_sbh[1]))
250 sbp = nilfs->ns_sbp[1];
254 spin_lock(&nilfs->ns_last_segment_lock);
255 nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq);
256 spin_unlock(&nilfs->ns_last_segment_lock);
263 int nilfs_commit_super(struct nilfs_sb_info *sbi, int dupsb)
265 struct the_nilfs *nilfs = sbi->s_nilfs;
266 struct nilfs_super_block **sbp = nilfs->ns_sbp;
267 sector_t nfreeblocks;
271 /* nilfs->sem must be locked by the caller. */
272 if (sbp[0]->s_magic != NILFS_SUPER_MAGIC) {
273 if (sbp[1] && sbp[1]->s_magic == NILFS_SUPER_MAGIC)
274 nilfs_swap_super_block(nilfs);
276 printk(KERN_CRIT "NILFS: superblock broke on dev %s\n",
281 err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
283 printk(KERN_ERR "NILFS: failed to count free blocks\n");
286 spin_lock(&nilfs->ns_last_segment_lock);
287 sbp[0]->s_last_seq = cpu_to_le64(nilfs->ns_last_seq);
288 sbp[0]->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg);
289 sbp[0]->s_last_cno = cpu_to_le64(nilfs->ns_last_cno);
290 spin_unlock(&nilfs->ns_last_segment_lock);
293 nilfs->ns_sbwtime[0] = t;
294 sbp[0]->s_free_blocks_count = cpu_to_le64(nfreeblocks);
295 sbp[0]->s_wtime = cpu_to_le64(t);
297 sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
298 (unsigned char *)sbp[0],
300 if (dupsb && sbp[1]) {
301 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
302 nilfs->ns_sbwtime[1] = t;
304 sbi->s_super->s_dirt = 0;
305 return nilfs_sync_super(sbi, dupsb);
308 static void nilfs_put_super(struct super_block *sb)
310 struct nilfs_sb_info *sbi = NILFS_SB(sb);
311 struct the_nilfs *nilfs = sbi->s_nilfs;
315 nilfs_detach_segment_constructor(sbi);
317 if (!(sb->s_flags & MS_RDONLY)) {
318 down_write(&nilfs->ns_sem);
319 nilfs->ns_sbp[0]->s_state = cpu_to_le16(nilfs->ns_mount_state);
320 nilfs_commit_super(sbi, 1);
321 up_write(&nilfs->ns_sem);
323 down_write(&nilfs->ns_super_sem);
324 if (nilfs->ns_current == sbi)
325 nilfs->ns_current = NULL;
326 up_write(&nilfs->ns_super_sem);
328 nilfs_detach_checkpoint(sbi);
329 put_nilfs(sbi->s_nilfs);
331 sb->s_fs_info = NULL;
332 nilfs_put_sbinfo(sbi);
337 static int nilfs_sync_fs(struct super_block *sb, int wait)
339 struct nilfs_sb_info *sbi = NILFS_SB(sb);
340 struct the_nilfs *nilfs = sbi->s_nilfs;
343 /* This function is called when super block should be written back */
345 err = nilfs_construct_segment(sb);
347 down_write(&nilfs->ns_sem);
349 nilfs_commit_super(sbi, 1);
350 up_write(&nilfs->ns_sem);
355 int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno)
357 struct the_nilfs *nilfs = sbi->s_nilfs;
358 struct nilfs_checkpoint *raw_cp;
359 struct buffer_head *bh_cp;
362 down_write(&nilfs->ns_super_sem);
363 list_add(&sbi->s_list, &nilfs->ns_supers);
364 up_write(&nilfs->ns_super_sem);
366 sbi->s_ifile = nilfs_mdt_new(nilfs, sbi->s_super, NILFS_IFILE_INO);
370 err = nilfs_palloc_init_blockgroup(sbi->s_ifile, nilfs->ns_inode_size);
374 down_read(&nilfs->ns_segctor_sem);
375 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp,
377 up_read(&nilfs->ns_segctor_sem);
379 if (err == -ENOENT || err == -EINVAL) {
381 "NILFS: Invalid checkpoint "
382 "(checkpoint number=%llu)\n",
383 (unsigned long long)cno);
388 err = nilfs_read_inode_common(sbi->s_ifile, &raw_cp->cp_ifile_inode);
391 atomic_set(&sbi->s_inodes_count, le64_to_cpu(raw_cp->cp_inodes_count));
392 atomic_set(&sbi->s_blocks_count, le64_to_cpu(raw_cp->cp_blocks_count));
394 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
398 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
400 nilfs_mdt_destroy(sbi->s_ifile);
403 down_write(&nilfs->ns_super_sem);
404 list_del_init(&sbi->s_list);
405 up_write(&nilfs->ns_super_sem);
410 void nilfs_detach_checkpoint(struct nilfs_sb_info *sbi)
412 struct the_nilfs *nilfs = sbi->s_nilfs;
414 nilfs_mdt_clear(sbi->s_ifile);
415 nilfs_mdt_destroy(sbi->s_ifile);
417 down_write(&nilfs->ns_super_sem);
418 list_del_init(&sbi->s_list);
419 up_write(&nilfs->ns_super_sem);
422 static int nilfs_mark_recovery_complete(struct nilfs_sb_info *sbi)
424 struct the_nilfs *nilfs = sbi->s_nilfs;
427 down_write(&nilfs->ns_sem);
428 if (!(nilfs->ns_mount_state & NILFS_VALID_FS)) {
429 nilfs->ns_mount_state |= NILFS_VALID_FS;
430 err = nilfs_commit_super(sbi, 1);
432 printk(KERN_INFO "NILFS: recovery complete.\n");
434 up_write(&nilfs->ns_sem);
438 static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
440 struct super_block *sb = dentry->d_sb;
441 struct nilfs_sb_info *sbi = NILFS_SB(sb);
442 struct the_nilfs *nilfs = sbi->s_nilfs;
443 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
444 unsigned long long blocks;
445 unsigned long overhead;
446 unsigned long nrsvblocks;
447 sector_t nfreeblocks;
451 * Compute all of the segment blocks
453 * The blocks before first segment and after last segment
456 blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments
457 - nilfs->ns_first_data_block;
458 nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment;
461 * Compute the overhead
463 * When distributing meta data blocks outside semgent structure,
464 * We must count them as the overhead.
468 err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
472 buf->f_type = NILFS_SUPER_MAGIC;
473 buf->f_bsize = sb->s_blocksize;
474 buf->f_blocks = blocks - overhead;
475 buf->f_bfree = nfreeblocks;
476 buf->f_bavail = (buf->f_bfree >= nrsvblocks) ?
477 (buf->f_bfree - nrsvblocks) : 0;
478 buf->f_files = atomic_read(&sbi->s_inodes_count);
479 buf->f_ffree = 0; /* nilfs_count_free_inodes(sb); */
480 buf->f_namelen = NILFS_NAME_LEN;
481 buf->f_fsid.val[0] = (u32)id;
482 buf->f_fsid.val[1] = (u32)(id >> 32);
487 static int nilfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
489 struct super_block *sb = vfs->mnt_sb;
490 struct nilfs_sb_info *sbi = NILFS_SB(sb);
492 if (!nilfs_test_opt(sbi, BARRIER))
493 seq_printf(seq, ",barrier=off");
494 if (nilfs_test_opt(sbi, SNAPSHOT))
495 seq_printf(seq, ",cp=%llu",
496 (unsigned long long int)sbi->s_snapshot_cno);
497 if (nilfs_test_opt(sbi, ERRORS_RO))
498 seq_printf(seq, ",errors=remount-ro");
499 if (nilfs_test_opt(sbi, ERRORS_PANIC))
500 seq_printf(seq, ",errors=panic");
501 if (nilfs_test_opt(sbi, STRICT_ORDER))
502 seq_printf(seq, ",order=strict");
507 static const struct super_operations nilfs_sops = {
508 .alloc_inode = nilfs_alloc_inode,
509 .destroy_inode = nilfs_destroy_inode,
510 .dirty_inode = nilfs_dirty_inode,
511 /* .write_inode = nilfs_write_inode, */
512 /* .put_inode = nilfs_put_inode, */
513 /* .drop_inode = nilfs_drop_inode, */
514 .delete_inode = nilfs_delete_inode,
515 .put_super = nilfs_put_super,
516 /* .write_super = nilfs_write_super, */
517 .sync_fs = nilfs_sync_fs,
518 /* .write_super_lockfs */
520 .statfs = nilfs_statfs,
521 .remount_fs = nilfs_remount,
522 .clear_inode = nilfs_clear_inode,
524 .show_options = nilfs_show_options
527 static struct inode *
528 nilfs_nfs_get_inode(struct super_block *sb, u64 ino, u32 generation)
532 if (ino < NILFS_FIRST_INO(sb) && ino != NILFS_ROOT_INO &&
533 ino != NILFS_SKETCH_INO)
534 return ERR_PTR(-ESTALE);
536 inode = nilfs_iget(sb, ino);
538 return ERR_CAST(inode);
539 if (generation && inode->i_generation != generation) {
541 return ERR_PTR(-ESTALE);
547 static struct dentry *
548 nilfs_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len,
551 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
552 nilfs_nfs_get_inode);
555 static struct dentry *
556 nilfs_fh_to_parent(struct super_block *sb, struct fid *fid, int fh_len,
559 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
560 nilfs_nfs_get_inode);
563 static const struct export_operations nilfs_export_ops = {
564 .fh_to_dentry = nilfs_fh_to_dentry,
565 .fh_to_parent = nilfs_fh_to_parent,
566 .get_parent = nilfs_get_parent,
570 Opt_err_cont, Opt_err_panic, Opt_err_ro,
571 Opt_barrier, Opt_snapshot, Opt_order,
575 static match_table_t tokens = {
576 {Opt_err_cont, "errors=continue"},
577 {Opt_err_panic, "errors=panic"},
578 {Opt_err_ro, "errors=remount-ro"},
579 {Opt_barrier, "barrier=%s"},
580 {Opt_snapshot, "cp=%u"},
581 {Opt_order, "order=%s"},
585 static int match_bool(substring_t *s, int *result)
587 int len = s->to - s->from;
589 if (strncmp(s->from, "on", len) == 0)
591 else if (strncmp(s->from, "off", len) == 0)
598 static int parse_options(char *options, struct super_block *sb)
600 struct nilfs_sb_info *sbi = NILFS_SB(sb);
602 substring_t args[MAX_OPT_ARGS];
608 while ((p = strsep(&options, ",")) != NULL) {
613 token = match_token(p, tokens, args);
616 if (match_bool(&args[0], &option))
619 nilfs_set_opt(sbi, BARRIER);
621 nilfs_clear_opt(sbi, BARRIER);
624 if (strcmp(args[0].from, "relaxed") == 0)
625 /* Ordered data semantics */
626 nilfs_clear_opt(sbi, STRICT_ORDER);
627 else if (strcmp(args[0].from, "strict") == 0)
628 /* Strict in-order semantics */
629 nilfs_set_opt(sbi, STRICT_ORDER);
634 nilfs_write_opt(sbi, ERROR_MODE, ERRORS_PANIC);
637 nilfs_write_opt(sbi, ERROR_MODE, ERRORS_RO);
640 nilfs_write_opt(sbi, ERROR_MODE, ERRORS_CONT);
643 if (match_int(&args[0], &option) || option <= 0)
645 if (!(sb->s_flags & MS_RDONLY))
647 sbi->s_snapshot_cno = option;
648 nilfs_set_opt(sbi, SNAPSHOT);
652 "NILFS: Unrecognized mount option \"%s\"\n", p);
660 nilfs_set_default_options(struct nilfs_sb_info *sbi,
661 struct nilfs_super_block *sbp)
664 NILFS_MOUNT_ERRORS_CONT | NILFS_MOUNT_BARRIER;
667 static int nilfs_setup_super(struct nilfs_sb_info *sbi)
669 struct the_nilfs *nilfs = sbi->s_nilfs;
670 struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
671 int max_mnt_count = le16_to_cpu(sbp->s_max_mnt_count);
672 int mnt_count = le16_to_cpu(sbp->s_mnt_count);
674 /* nilfs->sem must be locked by the caller. */
675 if (!(nilfs->ns_mount_state & NILFS_VALID_FS)) {
676 printk(KERN_WARNING "NILFS warning: mounting unchecked fs\n");
677 } else if (nilfs->ns_mount_state & NILFS_ERROR_FS) {
679 "NILFS warning: mounting fs with errors\n");
681 } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) {
683 "NILFS warning: maximal mount count reached\n");
687 sbp->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT);
689 sbp->s_mnt_count = cpu_to_le16(mnt_count + 1);
690 sbp->s_state = cpu_to_le16(le16_to_cpu(sbp->s_state) & ~NILFS_VALID_FS);
691 sbp->s_mtime = cpu_to_le64(get_seconds());
692 return nilfs_commit_super(sbi, 1);
695 struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb,
696 u64 pos, int blocksize,
697 struct buffer_head **pbh)
699 unsigned long long sb_index = pos;
700 unsigned long offset;
702 offset = do_div(sb_index, blocksize);
703 *pbh = sb_bread(sb, sb_index);
706 return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset);
709 int nilfs_store_magic_and_option(struct super_block *sb,
710 struct nilfs_super_block *sbp,
713 struct nilfs_sb_info *sbi = NILFS_SB(sb);
715 sb->s_magic = le16_to_cpu(sbp->s_magic);
717 /* FS independent flags */
718 #ifdef NILFS_ATIME_DISABLE
719 sb->s_flags |= MS_NOATIME;
722 nilfs_set_default_options(sbi, sbp);
724 sbi->s_resuid = le16_to_cpu(sbp->s_def_resuid);
725 sbi->s_resgid = le16_to_cpu(sbp->s_def_resgid);
726 sbi->s_interval = le32_to_cpu(sbp->s_c_interval);
727 sbi->s_watermark = le32_to_cpu(sbp->s_c_block_max);
729 return !parse_options(data, sb) ? -EINVAL : 0 ;
733 * nilfs_fill_super() - initialize a super block instance
735 * @data: mount options
736 * @silent: silent mode flag
737 * @nilfs: the_nilfs struct
739 * This function is called exclusively by nilfs->ns_mount_mutex.
740 * So, the recovery process is protected from other simultaneous mounts.
743 nilfs_fill_super(struct super_block *sb, void *data, int silent,
744 struct the_nilfs *nilfs)
746 struct nilfs_sb_info *sbi;
751 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
758 sbi->s_nilfs = nilfs;
760 atomic_set(&sbi->s_count, 1);
762 err = init_nilfs(nilfs, sbi, (char *)data);
766 spin_lock_init(&sbi->s_inode_lock);
767 INIT_LIST_HEAD(&sbi->s_dirty_files);
768 INIT_LIST_HEAD(&sbi->s_list);
771 * Following initialization is overlapped because
772 * nilfs_sb_info structure has been cleared at the beginning.
773 * But we reserve them to keep our interest and make ready
774 * for the future change.
776 get_random_bytes(&sbi->s_next_generation,
777 sizeof(sbi->s_next_generation));
778 spin_lock_init(&sbi->s_next_gen_lock);
780 sb->s_op = &nilfs_sops;
781 sb->s_export_op = &nilfs_export_ops;
785 if (!nilfs_loaded(nilfs)) {
786 err = load_nilfs(nilfs, sbi);
790 cno = nilfs_last_cno(nilfs);
792 if (sb->s_flags & MS_RDONLY) {
793 if (nilfs_test_opt(sbi, SNAPSHOT)) {
794 down_read(&nilfs->ns_segctor_sem);
795 err = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile,
796 sbi->s_snapshot_cno);
797 up_read(&nilfs->ns_segctor_sem);
805 "NILFS: The specified checkpoint is "
807 "(checkpoint number=%llu).\n",
808 (unsigned long long)sbi->s_snapshot_cno);
812 cno = sbi->s_snapshot_cno;
814 /* Read-only mount */
815 sbi->s_snapshot_cno = cno;
818 err = nilfs_attach_checkpoint(sbi, cno);
820 printk(KERN_ERR "NILFS: error loading a checkpoint"
821 " (checkpoint number=%llu).\n", (unsigned long long)cno);
825 if (!(sb->s_flags & MS_RDONLY)) {
826 err = nilfs_attach_segment_constructor(sbi);
828 goto failed_checkpoint;
831 root = nilfs_iget(sb, NILFS_ROOT_INO);
833 printk(KERN_ERR "NILFS: get root inode failed\n");
837 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
839 printk(KERN_ERR "NILFS: corrupt root inode.\n");
843 sb->s_root = d_alloc_root(root);
846 printk(KERN_ERR "NILFS: get root dentry failed\n");
851 if (!(sb->s_flags & MS_RDONLY)) {
852 down_write(&nilfs->ns_sem);
853 nilfs_setup_super(sbi);
854 up_write(&nilfs->ns_sem);
857 err = nilfs_mark_recovery_complete(sbi);
859 printk(KERN_ERR "NILFS: recovery failed.\n");
863 down_write(&nilfs->ns_super_sem);
864 if (!nilfs_test_opt(sbi, SNAPSHOT))
865 nilfs->ns_current = sbi;
866 up_write(&nilfs->ns_super_sem);
875 nilfs_detach_segment_constructor(sbi);
878 nilfs_detach_checkpoint(sbi);
882 sb->s_fs_info = NULL;
883 nilfs_put_sbinfo(sbi);
887 static int nilfs_remount(struct super_block *sb, int *flags, char *data)
889 struct nilfs_sb_info *sbi = NILFS_SB(sb);
890 struct nilfs_super_block *sbp;
891 struct the_nilfs *nilfs = sbi->s_nilfs;
892 unsigned long old_sb_flags;
893 struct nilfs_mount_options old_opts;
898 down_write(&nilfs->ns_super_sem);
899 old_sb_flags = sb->s_flags;
900 old_opts.mount_opt = sbi->s_mount_opt;
901 old_opts.snapshot_cno = sbi->s_snapshot_cno;
903 if (!parse_options(data, sb)) {
907 sb->s_flags = (sb->s_flags & ~MS_POSIXACL);
909 if ((*flags & MS_RDONLY) &&
910 sbi->s_snapshot_cno != old_opts.snapshot_cno) {
911 printk(KERN_WARNING "NILFS (device %s): couldn't "
912 "remount to a different snapshot. \n",
918 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
920 if (*flags & MS_RDONLY) {
921 /* Shutting down the segment constructor */
922 nilfs_detach_segment_constructor(sbi);
923 sb->s_flags |= MS_RDONLY;
925 sbi->s_snapshot_cno = nilfs_last_cno(nilfs);
926 /* nilfs_set_opt(sbi, SNAPSHOT); */
929 * Remounting a valid RW partition RDONLY, so set
930 * the RDONLY flag and then mark the partition as valid again.
932 down_write(&nilfs->ns_sem);
933 sbp = nilfs->ns_sbp[0];
934 if (!(sbp->s_state & le16_to_cpu(NILFS_VALID_FS)) &&
935 (nilfs->ns_mount_state & NILFS_VALID_FS))
936 sbp->s_state = cpu_to_le16(nilfs->ns_mount_state);
937 sbp->s_mtime = cpu_to_le64(get_seconds());
938 nilfs_commit_super(sbi, 1);
939 up_write(&nilfs->ns_sem);
942 * Mounting a RDONLY partition read-write, so reread and
943 * store the current valid flag. (It may have been changed
944 * by fsck since we originally mounted the partition.)
946 if (nilfs->ns_current && nilfs->ns_current != sbi) {
947 printk(KERN_WARNING "NILFS (device %s): couldn't "
948 "remount because an RW-mount exists.\n",
953 if (sbi->s_snapshot_cno != nilfs_last_cno(nilfs)) {
954 printk(KERN_WARNING "NILFS (device %s): couldn't "
955 "remount because the current RO-mount is not "
961 sb->s_flags &= ~MS_RDONLY;
962 nilfs_clear_opt(sbi, SNAPSHOT);
963 sbi->s_snapshot_cno = 0;
965 err = nilfs_attach_segment_constructor(sbi);
969 down_write(&nilfs->ns_sem);
970 nilfs_setup_super(sbi);
971 up_write(&nilfs->ns_sem);
973 nilfs->ns_current = sbi;
976 up_write(&nilfs->ns_super_sem);
981 sb->s_flags = old_sb_flags;
982 sbi->s_mount_opt = old_opts.mount_opt;
983 sbi->s_snapshot_cno = old_opts.snapshot_cno;
984 up_write(&nilfs->ns_super_sem);
989 struct nilfs_super_data {
990 struct block_device *bdev;
991 struct nilfs_sb_info *sbi;
997 * nilfs_identify - pre-read mount options needed to identify mount instance
998 * @data: mount options
999 * @sd: nilfs_super_data
1001 static int nilfs_identify(char *data, struct nilfs_super_data *sd)
1003 char *p, *options = data;
1004 substring_t args[MAX_OPT_ARGS];
1009 p = strsep(&options, ",");
1010 if (p != NULL && *p) {
1011 token = match_token(p, tokens, args);
1012 if (token == Opt_snapshot) {
1013 if (!(sd->flags & MS_RDONLY))
1016 ret = match_int(&args[0], &option);
1027 "NILFS: invalid mount option: %s\n", p);
1031 BUG_ON(options == data);
1032 *(options - 1) = ',';
1037 static int nilfs_set_bdev_super(struct super_block *s, void *data)
1039 struct nilfs_super_data *sd = data;
1041 s->s_bdev = sd->bdev;
1042 s->s_dev = s->s_bdev->bd_dev;
1046 static int nilfs_test_bdev_super(struct super_block *s, void *data)
1048 struct nilfs_super_data *sd = data;
1050 return sd->sbi && s->s_fs_info == (void *)sd->sbi;
1054 nilfs_get_sb(struct file_system_type *fs_type, int flags,
1055 const char *dev_name, void *data, struct vfsmount *mnt)
1057 struct nilfs_super_data sd;
1058 struct super_block *s;
1059 struct the_nilfs *nilfs;
1060 int err, need_to_close = 1;
1062 sd.bdev = open_bdev_exclusive(dev_name, flags, fs_type);
1063 if (IS_ERR(sd.bdev))
1064 return PTR_ERR(sd.bdev);
1067 * To get mount instance using sget() vfs-routine, NILFS needs
1068 * much more information than normal filesystems to identify mount
1069 * instance. For snapshot mounts, not only a mount type (ro-mount
1070 * or rw-mount) but also a checkpoint number is required.
1074 if (nilfs_identify((char *)data, &sd)) {
1079 nilfs = find_or_create_nilfs(sd.bdev);
1085 mutex_lock(&nilfs->ns_mount_mutex);
1089 * Check if an exclusive mount exists or not.
1090 * Snapshot mounts coexist with a current mount
1091 * (i.e. rw-mount or ro-mount), whereas rw-mount and
1092 * ro-mount are mutually exclusive.
1094 down_read(&nilfs->ns_super_sem);
1095 if (nilfs->ns_current &&
1096 ((nilfs->ns_current->s_super->s_flags ^ flags)
1098 up_read(&nilfs->ns_super_sem);
1102 up_read(&nilfs->ns_super_sem);
1106 * Find existing nilfs_sb_info struct
1108 sd.sbi = nilfs_find_sbinfo(nilfs, !(flags & MS_RDONLY), sd.cno);
1111 * Get super block instance holding the nilfs_sb_info struct.
1112 * A new instance is allocated if no existing mount is present or
1113 * existing instance has been unmounted.
1115 s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, &sd);
1117 nilfs_put_sbinfo(sd.sbi);
1125 char b[BDEVNAME_SIZE];
1127 /* New superblock instance created */
1129 strlcpy(s->s_id, bdevname(sd.bdev, b), sizeof(s->s_id));
1130 sb_set_blocksize(s, block_size(sd.bdev));
1132 err = nilfs_fill_super(s, data, flags & MS_VERBOSE, nilfs);
1136 s->s_flags |= MS_ACTIVE;
1140 mutex_unlock(&nilfs->ns_mount_mutex);
1143 close_bdev_exclusive(sd.bdev, flags);
1144 simple_set_mnt(mnt, s);
1148 mutex_unlock(&nilfs->ns_mount_mutex);
1151 close_bdev_exclusive(sd.bdev, flags);
1156 /* Abandoning the newly allocated superblock */
1157 mutex_unlock(&nilfs->ns_mount_mutex);
1159 up_write(&s->s_umount);
1160 deactivate_super(s);
1162 * deactivate_super() invokes close_bdev_exclusive().
1163 * We must finish all post-cleaning before this call;
1164 * put_nilfs() needs the block device.
1169 struct file_system_type nilfs_fs_type = {
1170 .owner = THIS_MODULE,
1172 .get_sb = nilfs_get_sb,
1173 .kill_sb = kill_block_super,
1174 .fs_flags = FS_REQUIRES_DEV,
1177 static int __init init_nilfs_fs(void)
1181 err = nilfs_init_inode_cache();
1185 err = nilfs_init_transaction_cache();
1187 goto failed_inode_cache;
1189 err = nilfs_init_segbuf_cache();
1191 goto failed_transaction_cache;
1193 err = nilfs_btree_path_cache_init();
1195 goto failed_segbuf_cache;
1197 err = register_filesystem(&nilfs_fs_type);
1199 goto failed_btree_path_cache;
1203 failed_btree_path_cache:
1204 nilfs_btree_path_cache_destroy();
1206 failed_segbuf_cache:
1207 nilfs_destroy_segbuf_cache();
1209 failed_transaction_cache:
1210 nilfs_destroy_transaction_cache();
1213 nilfs_destroy_inode_cache();
1219 static void __exit exit_nilfs_fs(void)
1221 nilfs_destroy_segbuf_cache();
1222 nilfs_destroy_transaction_cache();
1223 nilfs_destroy_inode_cache();
1224 nilfs_btree_path_cache_destroy();
1225 unregister_filesystem(&nilfs_fs_type);
1228 module_init(init_nilfs_fs)
1229 module_exit(exit_nilfs_fs)