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/vfs.h>
49 #include <linux/writeback.h>
50 #include <linux/kobject.h>
51 #include <linux/seq_file.h>
52 #include <linux/mount.h>
66 MODULE_AUTHOR("NTT Corp.");
67 MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem "
69 MODULE_LICENSE("GPL");
71 struct kmem_cache *nilfs_inode_cachep;
72 struct kmem_cache *nilfs_transaction_cachep;
73 struct kmem_cache *nilfs_segbuf_cachep;
74 struct kmem_cache *nilfs_btree_path_cache;
76 static int nilfs_remount(struct super_block *sb, int *flags, char *data);
78 static void nilfs_set_error(struct nilfs_sb_info *sbi)
80 struct the_nilfs *nilfs = sbi->s_nilfs;
81 struct nilfs_super_block **sbp;
83 down_write(&nilfs->ns_sem);
84 if (!(nilfs->ns_mount_state & NILFS_ERROR_FS)) {
85 nilfs->ns_mount_state |= NILFS_ERROR_FS;
86 sbp = nilfs_prepare_super(sbi, 0);
88 sbp[0]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
90 sbp[1]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
91 nilfs_commit_super(sbi, NILFS_SB_COMMIT_ALL);
94 up_write(&nilfs->ns_sem);
98 * nilfs_error() - report failure condition on a filesystem
100 * nilfs_error() sets an ERROR_FS flag on the superblock as well as
101 * reporting an error message. It should be called when NILFS detects
102 * incoherences or defects of meta data on disk. As for sustainable
103 * errors such as a single-shot I/O error, nilfs_warning() or the printk()
104 * function should be used instead.
106 * The segment constructor must not call this function because it can
109 void nilfs_error(struct super_block *sb, const char *function,
110 const char *fmt, ...)
112 struct nilfs_sb_info *sbi = NILFS_SB(sb);
116 printk(KERN_CRIT "NILFS error (device %s): %s: ", sb->s_id, function);
121 if (!(sb->s_flags & MS_RDONLY)) {
122 nilfs_set_error(sbi);
124 if (nilfs_test_opt(sbi, ERRORS_RO)) {
125 printk(KERN_CRIT "Remounting filesystem read-only\n");
126 sb->s_flags |= MS_RDONLY;
130 if (nilfs_test_opt(sbi, ERRORS_PANIC))
131 panic("NILFS (device %s): panic forced after error\n",
135 void nilfs_warning(struct super_block *sb, const char *function,
136 const char *fmt, ...)
141 printk(KERN_WARNING "NILFS warning (device %s): %s: ",
149 struct inode *nilfs_alloc_inode(struct super_block *sb)
151 struct nilfs_inode_info *ii;
153 ii = kmem_cache_alloc(nilfs_inode_cachep, GFP_NOFS);
159 ii->vfs_inode.i_version = 1;
160 nilfs_btnode_cache_init(&ii->i_btnode_cache, sb->s_bdi);
161 return &ii->vfs_inode;
164 void nilfs_destroy_inode(struct inode *inode)
166 struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
169 kfree(mdi->mi_bgl); /* kfree(NULL) is safe */
172 kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode));
175 static int nilfs_sync_super(struct nilfs_sb_info *sbi, int flag)
177 struct the_nilfs *nilfs = sbi->s_nilfs;
181 set_buffer_dirty(nilfs->ns_sbh[0]);
183 if (nilfs_test_opt(sbi, BARRIER)) {
184 err = __sync_dirty_buffer(nilfs->ns_sbh[0],
185 WRITE_SYNC | WRITE_BARRIER);
186 if (err == -EOPNOTSUPP) {
187 nilfs_warning(sbi->s_super, __func__,
188 "barrier-based sync failed. "
189 "disabling barriers\n");
190 nilfs_clear_opt(sbi, BARRIER);
194 err = sync_dirty_buffer(nilfs->ns_sbh[0]);
199 "NILFS: unable to write superblock (err=%d)\n", err);
200 if (err == -EIO && nilfs->ns_sbh[1]) {
202 * sbp[0] points to newer log than sbp[1],
203 * so copy sbp[0] to sbp[1] to take over sbp[0].
205 memcpy(nilfs->ns_sbp[1], nilfs->ns_sbp[0],
207 nilfs_fall_back_super_block(nilfs);
211 struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
213 nilfs->ns_sbwcount++;
216 * The latest segment becomes trailable from the position
217 * written in superblock.
219 clear_nilfs_discontinued(nilfs);
221 /* update GC protection for recent segments */
222 if (nilfs->ns_sbh[1]) {
223 if (flag == NILFS_SB_COMMIT_ALL) {
224 set_buffer_dirty(nilfs->ns_sbh[1]);
225 if (sync_dirty_buffer(nilfs->ns_sbh[1]) < 0)
228 if (le64_to_cpu(nilfs->ns_sbp[1]->s_last_cno) <
229 le64_to_cpu(nilfs->ns_sbp[0]->s_last_cno))
230 sbp = nilfs->ns_sbp[1];
233 spin_lock(&nilfs->ns_last_segment_lock);
234 nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq);
235 spin_unlock(&nilfs->ns_last_segment_lock);
241 void nilfs_set_log_cursor(struct nilfs_super_block *sbp,
242 struct the_nilfs *nilfs)
244 sector_t nfreeblocks;
246 /* nilfs->ns_sem must be locked by the caller. */
247 nilfs_count_free_blocks(nilfs, &nfreeblocks);
248 sbp->s_free_blocks_count = cpu_to_le64(nfreeblocks);
250 spin_lock(&nilfs->ns_last_segment_lock);
251 sbp->s_last_seq = cpu_to_le64(nilfs->ns_last_seq);
252 sbp->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg);
253 sbp->s_last_cno = cpu_to_le64(nilfs->ns_last_cno);
254 spin_unlock(&nilfs->ns_last_segment_lock);
257 struct nilfs_super_block **nilfs_prepare_super(struct nilfs_sb_info *sbi,
260 struct the_nilfs *nilfs = sbi->s_nilfs;
261 struct nilfs_super_block **sbp = nilfs->ns_sbp;
263 /* nilfs->ns_sem must be locked by the caller. */
264 if (sbp[0]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
266 sbp[1]->s_magic == cpu_to_le16(NILFS_SUPER_MAGIC)) {
267 memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
269 printk(KERN_CRIT "NILFS: superblock broke on dev %s\n",
274 sbp[1]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
275 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
279 nilfs_swap_super_block(nilfs);
284 int nilfs_commit_super(struct nilfs_sb_info *sbi, int flag)
286 struct the_nilfs *nilfs = sbi->s_nilfs;
287 struct nilfs_super_block **sbp = nilfs->ns_sbp;
290 /* nilfs->ns_sem must be locked by the caller. */
292 nilfs->ns_sbwtime = t;
293 sbp[0]->s_wtime = cpu_to_le64(t);
295 sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
296 (unsigned char *)sbp[0],
298 if (flag == NILFS_SB_COMMIT_ALL && sbp[1]) {
299 sbp[1]->s_wtime = sbp[0]->s_wtime;
301 sbp[1]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
302 (unsigned char *)sbp[1],
305 clear_nilfs_sb_dirty(nilfs);
306 return nilfs_sync_super(sbi, flag);
310 * nilfs_cleanup_super() - write filesystem state for cleanup
311 * @sbi: nilfs_sb_info to be unmounted or degraded to read-only
313 * This function restores state flags in the on-disk super block.
314 * This will set "clean" flag (i.e. NILFS_VALID_FS) unless the
315 * filesystem was not clean previously.
317 int nilfs_cleanup_super(struct nilfs_sb_info *sbi)
319 struct nilfs_super_block **sbp;
320 int flag = NILFS_SB_COMMIT;
323 sbp = nilfs_prepare_super(sbi, 0);
325 sbp[0]->s_state = cpu_to_le16(sbi->s_nilfs->ns_mount_state);
326 nilfs_set_log_cursor(sbp[0], sbi->s_nilfs);
327 if (sbp[1] && sbp[0]->s_last_cno == sbp[1]->s_last_cno) {
329 * make the "clean" flag also to the opposite
330 * super block if both super blocks point to
331 * the same checkpoint.
333 sbp[1]->s_state = sbp[0]->s_state;
334 flag = NILFS_SB_COMMIT_ALL;
336 ret = nilfs_commit_super(sbi, flag);
341 static void nilfs_put_super(struct super_block *sb)
343 struct nilfs_sb_info *sbi = NILFS_SB(sb);
344 struct the_nilfs *nilfs = sbi->s_nilfs;
346 nilfs_detach_segment_constructor(sbi);
348 if (!(sb->s_flags & MS_RDONLY)) {
349 down_write(&nilfs->ns_sem);
350 nilfs_cleanup_super(sbi);
351 up_write(&nilfs->ns_sem);
354 iput(nilfs->ns_sufile);
355 iput(nilfs->ns_cpfile);
358 destroy_nilfs(nilfs);
360 sb->s_fs_info = NULL;
364 static int nilfs_sync_fs(struct super_block *sb, int wait)
366 struct nilfs_sb_info *sbi = NILFS_SB(sb);
367 struct the_nilfs *nilfs = sbi->s_nilfs;
368 struct nilfs_super_block **sbp;
371 /* This function is called when super block should be written back */
373 err = nilfs_construct_segment(sb);
375 down_write(&nilfs->ns_sem);
376 if (nilfs_sb_dirty(nilfs)) {
377 sbp = nilfs_prepare_super(sbi, nilfs_sb_will_flip(nilfs));
379 nilfs_set_log_cursor(sbp[0], nilfs);
380 nilfs_commit_super(sbi, NILFS_SB_COMMIT);
383 up_write(&nilfs->ns_sem);
388 int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno, int curr_mnt,
389 struct nilfs_root **rootp)
391 struct the_nilfs *nilfs = sbi->s_nilfs;
392 struct nilfs_root *root;
393 struct nilfs_checkpoint *raw_cp;
394 struct buffer_head *bh_cp;
397 root = nilfs_find_or_create_root(
398 nilfs, curr_mnt ? NILFS_CPTREE_CURRENT_CNO : cno);
403 goto reuse; /* already attached checkpoint */
405 down_read(&nilfs->ns_segctor_sem);
406 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp,
408 up_read(&nilfs->ns_segctor_sem);
410 if (err == -ENOENT || err == -EINVAL) {
412 "NILFS: Invalid checkpoint "
413 "(checkpoint number=%llu)\n",
414 (unsigned long long)cno);
420 err = nilfs_ifile_read(sbi->s_super, root, nilfs->ns_inode_size,
421 &raw_cp->cp_ifile_inode, &root->ifile);
425 atomic_set(&root->inodes_count, le64_to_cpu(raw_cp->cp_inodes_count));
426 atomic_set(&root->blocks_count, le64_to_cpu(raw_cp->cp_blocks_count));
428 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
435 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
437 nilfs_put_root(root);
442 static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
444 struct super_block *sb = dentry->d_sb;
445 struct nilfs_root *root = NILFS_I(dentry->d_inode)->i_root;
446 struct the_nilfs *nilfs = root->nilfs;
447 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
448 unsigned long long blocks;
449 unsigned long overhead;
450 unsigned long nrsvblocks;
451 sector_t nfreeblocks;
455 * Compute all of the segment blocks
457 * The blocks before first segment and after last segment
460 blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments
461 - nilfs->ns_first_data_block;
462 nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment;
465 * Compute the overhead
467 * When distributing meta data blocks outside segment structure,
468 * We must count them as the overhead.
472 err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
476 buf->f_type = NILFS_SUPER_MAGIC;
477 buf->f_bsize = sb->s_blocksize;
478 buf->f_blocks = blocks - overhead;
479 buf->f_bfree = nfreeblocks;
480 buf->f_bavail = (buf->f_bfree >= nrsvblocks) ?
481 (buf->f_bfree - nrsvblocks) : 0;
482 buf->f_files = atomic_read(&root->inodes_count);
483 buf->f_ffree = 0; /* nilfs_count_free_inodes(sb); */
484 buf->f_namelen = NILFS_NAME_LEN;
485 buf->f_fsid.val[0] = (u32)id;
486 buf->f_fsid.val[1] = (u32)(id >> 32);
491 static int nilfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
493 struct super_block *sb = vfs->mnt_sb;
494 struct nilfs_sb_info *sbi = NILFS_SB(sb);
495 struct nilfs_root *root = NILFS_I(vfs->mnt_root->d_inode)->i_root;
497 if (!nilfs_test_opt(sbi, BARRIER))
498 seq_puts(seq, ",nobarrier");
499 if (root->cno != NILFS_CPTREE_CURRENT_CNO)
500 seq_printf(seq, ",cp=%llu", (unsigned long long)root->cno);
501 if (nilfs_test_opt(sbi, ERRORS_PANIC))
502 seq_puts(seq, ",errors=panic");
503 if (nilfs_test_opt(sbi, ERRORS_CONT))
504 seq_puts(seq, ",errors=continue");
505 if (nilfs_test_opt(sbi, STRICT_ORDER))
506 seq_puts(seq, ",order=strict");
507 if (nilfs_test_opt(sbi, NORECOVERY))
508 seq_puts(seq, ",norecovery");
509 if (nilfs_test_opt(sbi, DISCARD))
510 seq_puts(seq, ",discard");
515 static const struct super_operations nilfs_sops = {
516 .alloc_inode = nilfs_alloc_inode,
517 .destroy_inode = nilfs_destroy_inode,
518 .dirty_inode = nilfs_dirty_inode,
519 /* .write_inode = nilfs_write_inode, */
520 /* .put_inode = nilfs_put_inode, */
521 /* .drop_inode = nilfs_drop_inode, */
522 .evict_inode = nilfs_evict_inode,
523 .put_super = nilfs_put_super,
524 /* .write_super = nilfs_write_super, */
525 .sync_fs = nilfs_sync_fs,
526 /* .write_super_lockfs */
528 .statfs = nilfs_statfs,
529 .remount_fs = nilfs_remount,
531 .show_options = nilfs_show_options
535 Opt_err_cont, Opt_err_panic, Opt_err_ro,
536 Opt_barrier, Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery,
537 Opt_discard, Opt_nodiscard, Opt_err,
540 static match_table_t tokens = {
541 {Opt_err_cont, "errors=continue"},
542 {Opt_err_panic, "errors=panic"},
543 {Opt_err_ro, "errors=remount-ro"},
544 {Opt_barrier, "barrier"},
545 {Opt_nobarrier, "nobarrier"},
546 {Opt_snapshot, "cp=%u"},
547 {Opt_order, "order=%s"},
548 {Opt_norecovery, "norecovery"},
549 {Opt_discard, "discard"},
550 {Opt_nodiscard, "nodiscard"},
554 static int parse_options(char *options, struct super_block *sb, int is_remount)
556 struct nilfs_sb_info *sbi = NILFS_SB(sb);
558 substring_t args[MAX_OPT_ARGS];
564 while ((p = strsep(&options, ",")) != NULL) {
569 token = match_token(p, tokens, args);
572 nilfs_set_opt(sbi, BARRIER);
575 nilfs_clear_opt(sbi, BARRIER);
578 if (strcmp(args[0].from, "relaxed") == 0)
579 /* Ordered data semantics */
580 nilfs_clear_opt(sbi, STRICT_ORDER);
581 else if (strcmp(args[0].from, "strict") == 0)
582 /* Strict in-order semantics */
583 nilfs_set_opt(sbi, STRICT_ORDER);
588 nilfs_write_opt(sbi, ERROR_MODE, ERRORS_PANIC);
591 nilfs_write_opt(sbi, ERROR_MODE, ERRORS_RO);
594 nilfs_write_opt(sbi, ERROR_MODE, ERRORS_CONT);
597 if (match_int(&args[0], &option) || option <= 0)
601 "NILFS: \"%s\" option is invalid "
602 "for remount.\n", p);
607 nilfs_set_opt(sbi, NORECOVERY);
610 nilfs_set_opt(sbi, DISCARD);
613 nilfs_clear_opt(sbi, DISCARD);
617 "NILFS: Unrecognized mount option \"%s\"\n", p);
625 nilfs_set_default_options(struct nilfs_sb_info *sbi,
626 struct nilfs_super_block *sbp)
629 NILFS_MOUNT_ERRORS_RO | NILFS_MOUNT_BARRIER;
632 static int nilfs_setup_super(struct nilfs_sb_info *sbi)
634 struct the_nilfs *nilfs = sbi->s_nilfs;
635 struct nilfs_super_block **sbp;
639 /* nilfs->ns_sem must be locked by the caller. */
640 sbp = nilfs_prepare_super(sbi, 0);
644 max_mnt_count = le16_to_cpu(sbp[0]->s_max_mnt_count);
645 mnt_count = le16_to_cpu(sbp[0]->s_mnt_count);
647 if (nilfs->ns_mount_state & NILFS_ERROR_FS) {
649 "NILFS warning: mounting fs with errors\n");
651 } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) {
653 "NILFS warning: maximal mount count reached\n");
657 sbp[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT);
659 sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1);
661 cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS);
662 sbp[0]->s_mtime = cpu_to_le64(get_seconds());
663 /* synchronize sbp[1] with sbp[0] */
664 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
665 return nilfs_commit_super(sbi, NILFS_SB_COMMIT_ALL);
668 struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb,
669 u64 pos, int blocksize,
670 struct buffer_head **pbh)
672 unsigned long long sb_index = pos;
673 unsigned long offset;
675 offset = do_div(sb_index, blocksize);
676 *pbh = sb_bread(sb, sb_index);
679 return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset);
682 int nilfs_store_magic_and_option(struct super_block *sb,
683 struct nilfs_super_block *sbp,
686 struct nilfs_sb_info *sbi = NILFS_SB(sb);
688 sb->s_magic = le16_to_cpu(sbp->s_magic);
690 /* FS independent flags */
691 #ifdef NILFS_ATIME_DISABLE
692 sb->s_flags |= MS_NOATIME;
695 nilfs_set_default_options(sbi, sbp);
697 sbi->s_resuid = le16_to_cpu(sbp->s_def_resuid);
698 sbi->s_resgid = le16_to_cpu(sbp->s_def_resgid);
699 sbi->s_interval = le32_to_cpu(sbp->s_c_interval);
700 sbi->s_watermark = le32_to_cpu(sbp->s_c_block_max);
702 return !parse_options(data, sb, 0) ? -EINVAL : 0 ;
705 int nilfs_check_feature_compatibility(struct super_block *sb,
706 struct nilfs_super_block *sbp)
710 features = le64_to_cpu(sbp->s_feature_incompat) &
711 ~NILFS_FEATURE_INCOMPAT_SUPP;
713 printk(KERN_ERR "NILFS: couldn't mount because of unsupported "
714 "optional features (%llx)\n",
715 (unsigned long long)features);
718 features = le64_to_cpu(sbp->s_feature_compat_ro) &
719 ~NILFS_FEATURE_COMPAT_RO_SUPP;
720 if (!(sb->s_flags & MS_RDONLY) && features) {
721 printk(KERN_ERR "NILFS: couldn't mount RDWR because of "
722 "unsupported optional features (%llx)\n",
723 (unsigned long long)features);
729 static int nilfs_get_root_dentry(struct super_block *sb,
730 struct nilfs_root *root,
731 struct dentry **root_dentry)
734 struct dentry *dentry;
737 inode = nilfs_iget(sb, root, NILFS_ROOT_INO);
739 printk(KERN_ERR "NILFS: get root inode failed\n");
740 ret = PTR_ERR(inode);
743 if (!S_ISDIR(inode->i_mode) || !inode->i_blocks || !inode->i_size) {
745 printk(KERN_ERR "NILFS: corrupt root inode.\n");
750 if (root->cno == NILFS_CPTREE_CURRENT_CNO) {
751 dentry = d_find_alias(inode);
753 dentry = d_alloc_root(inode);
763 dentry = d_obtain_alias(inode);
764 if (IS_ERR(dentry)) {
765 ret = PTR_ERR(dentry);
769 *root_dentry = dentry;
774 printk(KERN_ERR "NILFS: get root dentry failed\n");
778 static int nilfs_attach_snapshot(struct super_block *s, __u64 cno,
779 struct dentry **root_dentry)
781 struct the_nilfs *nilfs = NILFS_SB(s)->s_nilfs;
782 struct nilfs_root *root;
785 down_read(&nilfs->ns_segctor_sem);
786 ret = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile, cno);
787 up_read(&nilfs->ns_segctor_sem);
789 ret = (ret == -ENOENT) ? -EINVAL : ret;
792 printk(KERN_ERR "NILFS: The specified checkpoint is "
793 "not a snapshot (checkpoint number=%llu).\n",
794 (unsigned long long)cno);
799 ret = nilfs_attach_checkpoint(NILFS_SB(s), cno, false, &root);
801 printk(KERN_ERR "NILFS: error loading snapshot "
802 "(checkpoint number=%llu).\n",
803 (unsigned long long)cno);
806 ret = nilfs_get_root_dentry(s, root, root_dentry);
807 nilfs_put_root(root);
812 static int nilfs_tree_was_touched(struct dentry *root_dentry)
814 return atomic_read(&root_dentry->d_count) > 1;
818 * nilfs_try_to_shrink_tree() - try to shrink dentries of a checkpoint
819 * @root_dentry: root dentry of the tree to be shrunk
821 * This function returns true if the tree was in-use.
823 static int nilfs_try_to_shrink_tree(struct dentry *root_dentry)
825 if (have_submounts(root_dentry))
827 shrink_dcache_parent(root_dentry);
828 return nilfs_tree_was_touched(root_dentry);
831 int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno)
833 struct the_nilfs *nilfs = NILFS_SB(sb)->s_nilfs;
834 struct nilfs_root *root;
836 struct dentry *dentry;
839 if (cno < 0 || cno > nilfs->ns_cno)
842 if (cno >= nilfs_last_cno(nilfs))
843 return true; /* protect recent checkpoints */
846 root = nilfs_lookup_root(NILFS_SB(sb)->s_nilfs, cno);
848 inode = nilfs_ilookup(sb, root, NILFS_ROOT_INO);
850 dentry = d_find_alias(inode);
852 if (nilfs_tree_was_touched(dentry))
853 ret = nilfs_try_to_shrink_tree(dentry);
858 nilfs_put_root(root);
864 * nilfs_fill_super() - initialize a super block instance
866 * @data: mount options
867 * @silent: silent mode flag
869 * This function is called exclusively by nilfs->ns_mount_mutex.
870 * So, the recovery process is protected from other simultaneous mounts.
873 nilfs_fill_super(struct super_block *sb, void *data, int silent)
875 struct the_nilfs *nilfs;
876 struct nilfs_sb_info *sbi;
877 struct nilfs_root *fsroot;
881 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
888 nilfs = alloc_nilfs(sb->s_bdev);
893 sbi->s_nilfs = nilfs;
895 err = init_nilfs(nilfs, sbi, (char *)data);
899 spin_lock_init(&sbi->s_inode_lock);
900 INIT_LIST_HEAD(&sbi->s_dirty_files);
903 * Following initialization is overlapped because
904 * nilfs_sb_info structure has been cleared at the beginning.
905 * But we reserve them to keep our interest and make ready
906 * for the future change.
908 get_random_bytes(&sbi->s_next_generation,
909 sizeof(sbi->s_next_generation));
910 spin_lock_init(&sbi->s_next_gen_lock);
912 sb->s_op = &nilfs_sops;
913 sb->s_export_op = &nilfs_export_ops;
916 sb->s_bdi = nilfs->ns_bdi;
918 err = load_nilfs(nilfs, sbi);
922 cno = nilfs_last_cno(nilfs);
923 err = nilfs_attach_checkpoint(sbi, cno, true, &fsroot);
925 printk(KERN_ERR "NILFS: error loading last checkpoint "
926 "(checkpoint number=%llu).\n", (unsigned long long)cno);
930 if (!(sb->s_flags & MS_RDONLY)) {
931 err = nilfs_attach_segment_constructor(sbi, fsroot);
933 goto failed_checkpoint;
936 err = nilfs_get_root_dentry(sb, fsroot, &sb->s_root);
940 nilfs_put_root(fsroot);
942 if (!(sb->s_flags & MS_RDONLY)) {
943 down_write(&nilfs->ns_sem);
944 nilfs_setup_super(sbi);
945 up_write(&nilfs->ns_sem);
951 nilfs_detach_segment_constructor(sbi);
954 nilfs_put_root(fsroot);
957 iput(nilfs->ns_sufile);
958 iput(nilfs->ns_cpfile);
962 destroy_nilfs(nilfs);
965 sb->s_fs_info = NULL;
970 static int nilfs_remount(struct super_block *sb, int *flags, char *data)
972 struct nilfs_sb_info *sbi = NILFS_SB(sb);
973 struct the_nilfs *nilfs = sbi->s_nilfs;
974 unsigned long old_sb_flags;
975 struct nilfs_mount_options old_opts;
978 old_sb_flags = sb->s_flags;
979 old_opts.mount_opt = sbi->s_mount_opt;
981 if (!parse_options(data, sb, 1)) {
985 sb->s_flags = (sb->s_flags & ~MS_POSIXACL);
989 if (!nilfs_valid_fs(nilfs)) {
990 printk(KERN_WARNING "NILFS (device %s): couldn't "
991 "remount because the filesystem is in an "
992 "incomplete recovery state.\n", sb->s_id);
996 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
998 if (*flags & MS_RDONLY) {
999 /* Shutting down the segment constructor */
1000 nilfs_detach_segment_constructor(sbi);
1001 sb->s_flags |= MS_RDONLY;
1004 * Remounting a valid RW partition RDONLY, so set
1005 * the RDONLY flag and then mark the partition as valid again.
1007 down_write(&nilfs->ns_sem);
1008 nilfs_cleanup_super(sbi);
1009 up_write(&nilfs->ns_sem);
1012 struct nilfs_root *root;
1015 * Mounting a RDONLY partition read-write, so reread and
1016 * store the current valid flag. (It may have been changed
1017 * by fsck since we originally mounted the partition.)
1019 down_read(&nilfs->ns_sem);
1020 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
1021 ~NILFS_FEATURE_COMPAT_RO_SUPP;
1022 up_read(&nilfs->ns_sem);
1024 printk(KERN_WARNING "NILFS (device %s): couldn't "
1025 "remount RDWR because of unsupported optional "
1026 "features (%llx)\n",
1027 sb->s_id, (unsigned long long)features);
1032 sb->s_flags &= ~MS_RDONLY;
1034 root = NILFS_I(sb->s_root->d_inode)->i_root;
1035 err = nilfs_attach_segment_constructor(sbi, root);
1039 down_write(&nilfs->ns_sem);
1040 nilfs_setup_super(sbi);
1041 up_write(&nilfs->ns_sem);
1047 sb->s_flags = old_sb_flags;
1048 sbi->s_mount_opt = old_opts.mount_opt;
1052 struct nilfs_super_data {
1053 struct block_device *bdev;
1054 struct nilfs_sb_info *sbi;
1060 * nilfs_identify - pre-read mount options needed to identify mount instance
1061 * @data: mount options
1062 * @sd: nilfs_super_data
1064 static int nilfs_identify(char *data, struct nilfs_super_data *sd)
1066 char *p, *options = data;
1067 substring_t args[MAX_OPT_ARGS];
1072 p = strsep(&options, ",");
1073 if (p != NULL && *p) {
1074 token = match_token(p, tokens, args);
1075 if (token == Opt_snapshot) {
1076 if (!(sd->flags & MS_RDONLY))
1079 ret = match_int(&args[0], &option);
1090 "NILFS: invalid mount option: %s\n", p);
1094 BUG_ON(options == data);
1095 *(options - 1) = ',';
1100 static int nilfs_set_bdev_super(struct super_block *s, void *data)
1103 s->s_dev = s->s_bdev->bd_dev;
1107 static int nilfs_test_bdev_super(struct super_block *s, void *data)
1109 return (void *)s->s_bdev == data;
1113 nilfs_get_sb(struct file_system_type *fs_type, int flags,
1114 const char *dev_name, void *data, struct vfsmount *mnt)
1116 struct nilfs_super_data sd;
1117 struct super_block *s;
1118 fmode_t mode = FMODE_READ;
1119 struct dentry *root_dentry;
1120 int err, s_new = false;
1122 if (!(flags & MS_RDONLY))
1123 mode |= FMODE_WRITE;
1125 sd.bdev = open_bdev_exclusive(dev_name, mode, fs_type);
1126 if (IS_ERR(sd.bdev))
1127 return PTR_ERR(sd.bdev);
1131 if (nilfs_identify((char *)data, &sd)) {
1136 s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, sd.bdev);
1143 char b[BDEVNAME_SIZE];
1147 /* New superblock instance created */
1150 strlcpy(s->s_id, bdevname(sd.bdev, b), sizeof(s->s_id));
1151 sb_set_blocksize(s, block_size(sd.bdev));
1153 err = nilfs_fill_super(s, data, flags & MS_SILENT ? 1 : 0);
1157 s->s_flags |= MS_ACTIVE;
1158 } else if (!sd.cno) {
1161 if (nilfs_tree_was_touched(s->s_root)) {
1162 busy = nilfs_try_to_shrink_tree(s->s_root);
1163 if (busy && (flags ^ s->s_flags) & MS_RDONLY) {
1164 printk(KERN_ERR "NILFS: the device already "
1165 "has a %s mount.\n",
1166 (s->s_flags & MS_RDONLY) ?
1167 "read-only" : "read/write");
1174 * Try remount to setup mount states if the current
1175 * tree is not mounted and only snapshots use this sb.
1177 err = nilfs_remount(s, &flags, data);
1184 err = nilfs_attach_snapshot(s, sd.cno, &root_dentry);
1188 root_dentry = dget(s->s_root);
1192 close_bdev_exclusive(sd.bdev, mode);
1195 mnt->mnt_root = root_dentry;
1199 deactivate_locked_super(s);
1203 close_bdev_exclusive(sd.bdev, mode);
1207 struct file_system_type nilfs_fs_type = {
1208 .owner = THIS_MODULE,
1210 .get_sb = nilfs_get_sb,
1211 .kill_sb = kill_block_super,
1212 .fs_flags = FS_REQUIRES_DEV,
1215 static void nilfs_inode_init_once(void *obj)
1217 struct nilfs_inode_info *ii = obj;
1219 INIT_LIST_HEAD(&ii->i_dirty);
1220 #ifdef CONFIG_NILFS_XATTR
1221 init_rwsem(&ii->xattr_sem);
1223 nilfs_btnode_cache_init_once(&ii->i_btnode_cache);
1224 ii->i_bmap = &ii->i_bmap_data;
1225 inode_init_once(&ii->vfs_inode);
1228 static void nilfs_segbuf_init_once(void *obj)
1230 memset(obj, 0, sizeof(struct nilfs_segment_buffer));
1233 static void nilfs_destroy_cachep(void)
1235 if (nilfs_inode_cachep)
1236 kmem_cache_destroy(nilfs_inode_cachep);
1237 if (nilfs_transaction_cachep)
1238 kmem_cache_destroy(nilfs_transaction_cachep);
1239 if (nilfs_segbuf_cachep)
1240 kmem_cache_destroy(nilfs_segbuf_cachep);
1241 if (nilfs_btree_path_cache)
1242 kmem_cache_destroy(nilfs_btree_path_cache);
1245 static int __init nilfs_init_cachep(void)
1247 nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache",
1248 sizeof(struct nilfs_inode_info), 0,
1249 SLAB_RECLAIM_ACCOUNT, nilfs_inode_init_once);
1250 if (!nilfs_inode_cachep)
1253 nilfs_transaction_cachep = kmem_cache_create("nilfs2_transaction_cache",
1254 sizeof(struct nilfs_transaction_info), 0,
1255 SLAB_RECLAIM_ACCOUNT, NULL);
1256 if (!nilfs_transaction_cachep)
1259 nilfs_segbuf_cachep = kmem_cache_create("nilfs2_segbuf_cache",
1260 sizeof(struct nilfs_segment_buffer), 0,
1261 SLAB_RECLAIM_ACCOUNT, nilfs_segbuf_init_once);
1262 if (!nilfs_segbuf_cachep)
1265 nilfs_btree_path_cache = kmem_cache_create("nilfs2_btree_path_cache",
1266 sizeof(struct nilfs_btree_path) * NILFS_BTREE_LEVEL_MAX,
1268 if (!nilfs_btree_path_cache)
1274 nilfs_destroy_cachep();
1278 static int __init init_nilfs_fs(void)
1282 err = nilfs_init_cachep();
1286 err = register_filesystem(&nilfs_fs_type);
1290 printk(KERN_INFO "NILFS version 2 loaded\n");
1294 nilfs_destroy_cachep();
1299 static void __exit exit_nilfs_fs(void)
1301 nilfs_destroy_cachep();
1302 unregister_filesystem(&nilfs_fs_type);
1305 module_init(init_nilfs_fs)
1306 module_exit(exit_nilfs_fs)