nilfs2: simplify life cycle management of nilfs object
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / nilfs2 / super.c
blob5893cb27c90921e6b83756070640024109e387d9
1 /*
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)
30 * from
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>
53 #include "nilfs.h"
54 #include "export.h"
55 #include "mdt.h"
56 #include "alloc.h"
57 #include "btree.h"
58 #include "btnode.h"
59 #include "page.h"
60 #include "cpfile.h"
61 #include "ifile.h"
62 #include "dat.h"
63 #include "segment.h"
64 #include "segbuf.h"
66 MODULE_AUTHOR("NTT Corp.");
67 MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem "
68 "(NILFS)");
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);
87 if (likely(sbp)) {
88 sbp[0]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
89 if (sbp[1])
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);
97 /**
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
107 * kill itself.
109 void nilfs_error(struct super_block *sb, const char *function,
110 const char *fmt, ...)
112 struct nilfs_sb_info *sbi = NILFS_SB(sb);
113 va_list args;
115 va_start(args, fmt);
116 printk(KERN_CRIT "NILFS error (device %s): %s: ", sb->s_id, function);
117 vprintk(fmt, args);
118 printk("\n");
119 va_end(args);
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",
132 sb->s_id);
135 void nilfs_warning(struct super_block *sb, const char *function,
136 const char *fmt, ...)
138 va_list args;
140 va_start(args, fmt);
141 printk(KERN_WARNING "NILFS warning (device %s): %s: ",
142 sb->s_id, function);
143 vprintk(fmt, args);
144 printk("\n");
145 va_end(args);
149 struct inode *nilfs_alloc_inode_common(struct the_nilfs *nilfs)
151 struct nilfs_inode_info *ii;
153 ii = kmem_cache_alloc(nilfs_inode_cachep, GFP_NOFS);
154 if (!ii)
155 return NULL;
156 ii->i_bh = NULL;
157 ii->i_state = 0;
158 ii->i_cno = 0;
159 ii->vfs_inode.i_version = 1;
160 nilfs_btnode_cache_init(&ii->i_btnode_cache, nilfs->ns_bdi);
161 return &ii->vfs_inode;
164 struct inode *nilfs_alloc_inode(struct super_block *sb)
166 return nilfs_alloc_inode_common(NILFS_SB(sb)->s_nilfs);
169 void nilfs_destroy_inode(struct inode *inode)
171 struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
173 if (mdi) {
174 kfree(mdi->mi_bgl); /* kfree(NULL) is safe */
175 kfree(mdi);
177 kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode));
180 static int nilfs_sync_super(struct nilfs_sb_info *sbi, int flag)
182 struct the_nilfs *nilfs = sbi->s_nilfs;
183 int err;
185 retry:
186 set_buffer_dirty(nilfs->ns_sbh[0]);
188 if (nilfs_test_opt(sbi, BARRIER)) {
189 err = __sync_dirty_buffer(nilfs->ns_sbh[0],
190 WRITE_SYNC | WRITE_BARRIER);
191 if (err == -EOPNOTSUPP) {
192 nilfs_warning(sbi->s_super, __func__,
193 "barrier-based sync failed. "
194 "disabling barriers\n");
195 nilfs_clear_opt(sbi, BARRIER);
196 goto retry;
198 } else {
199 err = sync_dirty_buffer(nilfs->ns_sbh[0]);
202 if (unlikely(err)) {
203 printk(KERN_ERR
204 "NILFS: unable to write superblock (err=%d)\n", err);
205 if (err == -EIO && nilfs->ns_sbh[1]) {
207 * sbp[0] points to newer log than sbp[1],
208 * so copy sbp[0] to sbp[1] to take over sbp[0].
210 memcpy(nilfs->ns_sbp[1], nilfs->ns_sbp[0],
211 nilfs->ns_sbsize);
212 nilfs_fall_back_super_block(nilfs);
213 goto retry;
215 } else {
216 struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
218 nilfs->ns_sbwcount++;
221 * The latest segment becomes trailable from the position
222 * written in superblock.
224 clear_nilfs_discontinued(nilfs);
226 /* update GC protection for recent segments */
227 if (nilfs->ns_sbh[1]) {
228 if (flag == NILFS_SB_COMMIT_ALL) {
229 set_buffer_dirty(nilfs->ns_sbh[1]);
230 if (sync_dirty_buffer(nilfs->ns_sbh[1]) < 0)
231 goto out;
233 if (le64_to_cpu(nilfs->ns_sbp[1]->s_last_cno) <
234 le64_to_cpu(nilfs->ns_sbp[0]->s_last_cno))
235 sbp = nilfs->ns_sbp[1];
238 spin_lock(&nilfs->ns_last_segment_lock);
239 nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq);
240 spin_unlock(&nilfs->ns_last_segment_lock);
242 out:
243 return err;
246 void nilfs_set_log_cursor(struct nilfs_super_block *sbp,
247 struct the_nilfs *nilfs)
249 sector_t nfreeblocks;
251 /* nilfs->ns_sem must be locked by the caller. */
252 nilfs_count_free_blocks(nilfs, &nfreeblocks);
253 sbp->s_free_blocks_count = cpu_to_le64(nfreeblocks);
255 spin_lock(&nilfs->ns_last_segment_lock);
256 sbp->s_last_seq = cpu_to_le64(nilfs->ns_last_seq);
257 sbp->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg);
258 sbp->s_last_cno = cpu_to_le64(nilfs->ns_last_cno);
259 spin_unlock(&nilfs->ns_last_segment_lock);
262 struct nilfs_super_block **nilfs_prepare_super(struct nilfs_sb_info *sbi,
263 int flip)
265 struct the_nilfs *nilfs = sbi->s_nilfs;
266 struct nilfs_super_block **sbp = nilfs->ns_sbp;
268 /* nilfs->ns_sem must be locked by the caller. */
269 if (sbp[0]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
270 if (sbp[1] &&
271 sbp[1]->s_magic == cpu_to_le16(NILFS_SUPER_MAGIC)) {
272 memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
273 } else {
274 printk(KERN_CRIT "NILFS: superblock broke on dev %s\n",
275 sbi->s_super->s_id);
276 return NULL;
278 } else if (sbp[1] &&
279 sbp[1]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
280 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
283 if (flip && sbp[1])
284 nilfs_swap_super_block(nilfs);
286 return sbp;
289 int nilfs_commit_super(struct nilfs_sb_info *sbi, int flag)
291 struct the_nilfs *nilfs = sbi->s_nilfs;
292 struct nilfs_super_block **sbp = nilfs->ns_sbp;
293 time_t t;
295 /* nilfs->ns_sem must be locked by the caller. */
296 t = get_seconds();
297 nilfs->ns_sbwtime = t;
298 sbp[0]->s_wtime = cpu_to_le64(t);
299 sbp[0]->s_sum = 0;
300 sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
301 (unsigned char *)sbp[0],
302 nilfs->ns_sbsize));
303 if (flag == NILFS_SB_COMMIT_ALL && sbp[1]) {
304 sbp[1]->s_wtime = sbp[0]->s_wtime;
305 sbp[1]->s_sum = 0;
306 sbp[1]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
307 (unsigned char *)sbp[1],
308 nilfs->ns_sbsize));
310 clear_nilfs_sb_dirty(nilfs);
311 return nilfs_sync_super(sbi, flag);
315 * nilfs_cleanup_super() - write filesystem state for cleanup
316 * @sbi: nilfs_sb_info to be unmounted or degraded to read-only
318 * This function restores state flags in the on-disk super block.
319 * This will set "clean" flag (i.e. NILFS_VALID_FS) unless the
320 * filesystem was not clean previously.
322 int nilfs_cleanup_super(struct nilfs_sb_info *sbi)
324 struct nilfs_super_block **sbp;
325 int flag = NILFS_SB_COMMIT;
326 int ret = -EIO;
328 sbp = nilfs_prepare_super(sbi, 0);
329 if (sbp) {
330 sbp[0]->s_state = cpu_to_le16(sbi->s_nilfs->ns_mount_state);
331 nilfs_set_log_cursor(sbp[0], sbi->s_nilfs);
332 if (sbp[1] && sbp[0]->s_last_cno == sbp[1]->s_last_cno) {
334 * make the "clean" flag also to the opposite
335 * super block if both super blocks point to
336 * the same checkpoint.
338 sbp[1]->s_state = sbp[0]->s_state;
339 flag = NILFS_SB_COMMIT_ALL;
341 ret = nilfs_commit_super(sbi, flag);
343 return ret;
346 static void nilfs_put_super(struct super_block *sb)
348 struct nilfs_sb_info *sbi = NILFS_SB(sb);
349 struct the_nilfs *nilfs = sbi->s_nilfs;
351 nilfs_detach_segment_constructor(sbi);
353 if (!(sb->s_flags & MS_RDONLY)) {
354 down_write(&nilfs->ns_sem);
355 nilfs_cleanup_super(sbi);
356 up_write(&nilfs->ns_sem);
359 destroy_nilfs(nilfs);
360 sbi->s_super = NULL;
361 sb->s_fs_info = NULL;
362 kfree(sbi);
365 static int nilfs_sync_fs(struct super_block *sb, int wait)
367 struct nilfs_sb_info *sbi = NILFS_SB(sb);
368 struct the_nilfs *nilfs = sbi->s_nilfs;
369 struct nilfs_super_block **sbp;
370 int err = 0;
372 /* This function is called when super block should be written back */
373 if (wait)
374 err = nilfs_construct_segment(sb);
376 down_write(&nilfs->ns_sem);
377 if (nilfs_sb_dirty(nilfs)) {
378 sbp = nilfs_prepare_super(sbi, nilfs_sb_will_flip(nilfs));
379 if (likely(sbp)) {
380 nilfs_set_log_cursor(sbp[0], nilfs);
381 nilfs_commit_super(sbi, NILFS_SB_COMMIT);
384 up_write(&nilfs->ns_sem);
386 return err;
389 int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno, int curr_mnt,
390 struct nilfs_root **rootp)
392 struct the_nilfs *nilfs = sbi->s_nilfs;
393 struct nilfs_root *root;
394 struct nilfs_checkpoint *raw_cp;
395 struct buffer_head *bh_cp;
396 int err = -ENOMEM;
398 root = nilfs_find_or_create_root(
399 nilfs, curr_mnt ? NILFS_CPTREE_CURRENT_CNO : cno);
400 if (!root)
401 return err;
403 if (root->ifile)
404 goto reuse; /* already attached checkpoint */
406 root->ifile = nilfs_ifile_new(sbi, nilfs->ns_inode_size);
407 if (!root->ifile)
408 goto failed;
410 down_read(&nilfs->ns_segctor_sem);
411 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp,
412 &bh_cp);
413 up_read(&nilfs->ns_segctor_sem);
414 if (unlikely(err)) {
415 if (err == -ENOENT || err == -EINVAL) {
416 printk(KERN_ERR
417 "NILFS: Invalid checkpoint "
418 "(checkpoint number=%llu)\n",
419 (unsigned long long)cno);
420 err = -EINVAL;
422 goto failed;
424 err = nilfs_read_inode_common(root->ifile, &raw_cp->cp_ifile_inode);
425 if (unlikely(err))
426 goto failed_bh;
428 atomic_set(&root->inodes_count, le64_to_cpu(raw_cp->cp_inodes_count));
429 atomic_set(&root->blocks_count, le64_to_cpu(raw_cp->cp_blocks_count));
431 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
433 reuse:
434 *rootp = root;
435 return 0;
437 failed_bh:
438 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
439 failed:
440 nilfs_put_root(root);
442 return err;
445 static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
447 struct super_block *sb = dentry->d_sb;
448 struct nilfs_root *root = NILFS_I(dentry->d_inode)->i_root;
449 struct the_nilfs *nilfs = root->nilfs;
450 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
451 unsigned long long blocks;
452 unsigned long overhead;
453 unsigned long nrsvblocks;
454 sector_t nfreeblocks;
455 int err;
458 * Compute all of the segment blocks
460 * The blocks before first segment and after last segment
461 * are excluded.
463 blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments
464 - nilfs->ns_first_data_block;
465 nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment;
468 * Compute the overhead
470 * When distributing meta data blocks outside segment structure,
471 * We must count them as the overhead.
473 overhead = 0;
475 err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
476 if (unlikely(err))
477 return err;
479 buf->f_type = NILFS_SUPER_MAGIC;
480 buf->f_bsize = sb->s_blocksize;
481 buf->f_blocks = blocks - overhead;
482 buf->f_bfree = nfreeblocks;
483 buf->f_bavail = (buf->f_bfree >= nrsvblocks) ?
484 (buf->f_bfree - nrsvblocks) : 0;
485 buf->f_files = atomic_read(&root->inodes_count);
486 buf->f_ffree = 0; /* nilfs_count_free_inodes(sb); */
487 buf->f_namelen = NILFS_NAME_LEN;
488 buf->f_fsid.val[0] = (u32)id;
489 buf->f_fsid.val[1] = (u32)(id >> 32);
491 return 0;
494 static int nilfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
496 struct super_block *sb = vfs->mnt_sb;
497 struct nilfs_sb_info *sbi = NILFS_SB(sb);
498 struct nilfs_root *root = NILFS_I(vfs->mnt_root->d_inode)->i_root;
500 if (!nilfs_test_opt(sbi, BARRIER))
501 seq_puts(seq, ",nobarrier");
502 if (root->cno != NILFS_CPTREE_CURRENT_CNO)
503 seq_printf(seq, ",cp=%llu", (unsigned long long)root->cno);
504 if (nilfs_test_opt(sbi, ERRORS_PANIC))
505 seq_puts(seq, ",errors=panic");
506 if (nilfs_test_opt(sbi, ERRORS_CONT))
507 seq_puts(seq, ",errors=continue");
508 if (nilfs_test_opt(sbi, STRICT_ORDER))
509 seq_puts(seq, ",order=strict");
510 if (nilfs_test_opt(sbi, NORECOVERY))
511 seq_puts(seq, ",norecovery");
512 if (nilfs_test_opt(sbi, DISCARD))
513 seq_puts(seq, ",discard");
515 return 0;
518 static const struct super_operations nilfs_sops = {
519 .alloc_inode = nilfs_alloc_inode,
520 .destroy_inode = nilfs_destroy_inode,
521 .dirty_inode = nilfs_dirty_inode,
522 /* .write_inode = nilfs_write_inode, */
523 /* .put_inode = nilfs_put_inode, */
524 /* .drop_inode = nilfs_drop_inode, */
525 .evict_inode = nilfs_evict_inode,
526 .put_super = nilfs_put_super,
527 /* .write_super = nilfs_write_super, */
528 .sync_fs = nilfs_sync_fs,
529 /* .write_super_lockfs */
530 /* .unlockfs */
531 .statfs = nilfs_statfs,
532 .remount_fs = nilfs_remount,
533 /* .umount_begin */
534 .show_options = nilfs_show_options
537 enum {
538 Opt_err_cont, Opt_err_panic, Opt_err_ro,
539 Opt_barrier, Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery,
540 Opt_discard, Opt_nodiscard, Opt_err,
543 static match_table_t tokens = {
544 {Opt_err_cont, "errors=continue"},
545 {Opt_err_panic, "errors=panic"},
546 {Opt_err_ro, "errors=remount-ro"},
547 {Opt_barrier, "barrier"},
548 {Opt_nobarrier, "nobarrier"},
549 {Opt_snapshot, "cp=%u"},
550 {Opt_order, "order=%s"},
551 {Opt_norecovery, "norecovery"},
552 {Opt_discard, "discard"},
553 {Opt_nodiscard, "nodiscard"},
554 {Opt_err, NULL}
557 static int parse_options(char *options, struct super_block *sb, int is_remount)
559 struct nilfs_sb_info *sbi = NILFS_SB(sb);
560 char *p;
561 substring_t args[MAX_OPT_ARGS];
562 int option;
564 if (!options)
565 return 1;
567 while ((p = strsep(&options, ",")) != NULL) {
568 int token;
569 if (!*p)
570 continue;
572 token = match_token(p, tokens, args);
573 switch (token) {
574 case Opt_barrier:
575 nilfs_set_opt(sbi, BARRIER);
576 break;
577 case Opt_nobarrier:
578 nilfs_clear_opt(sbi, BARRIER);
579 break;
580 case Opt_order:
581 if (strcmp(args[0].from, "relaxed") == 0)
582 /* Ordered data semantics */
583 nilfs_clear_opt(sbi, STRICT_ORDER);
584 else if (strcmp(args[0].from, "strict") == 0)
585 /* Strict in-order semantics */
586 nilfs_set_opt(sbi, STRICT_ORDER);
587 else
588 return 0;
589 break;
590 case Opt_err_panic:
591 nilfs_write_opt(sbi, ERROR_MODE, ERRORS_PANIC);
592 break;
593 case Opt_err_ro:
594 nilfs_write_opt(sbi, ERROR_MODE, ERRORS_RO);
595 break;
596 case Opt_err_cont:
597 nilfs_write_opt(sbi, ERROR_MODE, ERRORS_CONT);
598 break;
599 case Opt_snapshot:
600 if (match_int(&args[0], &option) || option <= 0)
601 return 0;
602 if (is_remount) {
603 printk(KERN_ERR
604 "NILFS: \"%s\" option is invalid "
605 "for remount.\n", p);
606 return 0;
608 break;
609 case Opt_norecovery:
610 nilfs_set_opt(sbi, NORECOVERY);
611 break;
612 case Opt_discard:
613 nilfs_set_opt(sbi, DISCARD);
614 break;
615 case Opt_nodiscard:
616 nilfs_clear_opt(sbi, DISCARD);
617 break;
618 default:
619 printk(KERN_ERR
620 "NILFS: Unrecognized mount option \"%s\"\n", p);
621 return 0;
624 return 1;
627 static inline void
628 nilfs_set_default_options(struct nilfs_sb_info *sbi,
629 struct nilfs_super_block *sbp)
631 sbi->s_mount_opt =
632 NILFS_MOUNT_ERRORS_RO | NILFS_MOUNT_BARRIER;
635 static int nilfs_setup_super(struct nilfs_sb_info *sbi)
637 struct the_nilfs *nilfs = sbi->s_nilfs;
638 struct nilfs_super_block **sbp;
639 int max_mnt_count;
640 int mnt_count;
642 /* nilfs->ns_sem must be locked by the caller. */
643 sbp = nilfs_prepare_super(sbi, 0);
644 if (!sbp)
645 return -EIO;
647 max_mnt_count = le16_to_cpu(sbp[0]->s_max_mnt_count);
648 mnt_count = le16_to_cpu(sbp[0]->s_mnt_count);
650 if (nilfs->ns_mount_state & NILFS_ERROR_FS) {
651 printk(KERN_WARNING
652 "NILFS warning: mounting fs with errors\n");
653 #if 0
654 } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) {
655 printk(KERN_WARNING
656 "NILFS warning: maximal mount count reached\n");
657 #endif
659 if (!max_mnt_count)
660 sbp[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT);
662 sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1);
663 sbp[0]->s_state =
664 cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS);
665 sbp[0]->s_mtime = cpu_to_le64(get_seconds());
666 /* synchronize sbp[1] with sbp[0] */
667 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
668 return nilfs_commit_super(sbi, NILFS_SB_COMMIT_ALL);
671 struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb,
672 u64 pos, int blocksize,
673 struct buffer_head **pbh)
675 unsigned long long sb_index = pos;
676 unsigned long offset;
678 offset = do_div(sb_index, blocksize);
679 *pbh = sb_bread(sb, sb_index);
680 if (!*pbh)
681 return NULL;
682 return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset);
685 int nilfs_store_magic_and_option(struct super_block *sb,
686 struct nilfs_super_block *sbp,
687 char *data)
689 struct nilfs_sb_info *sbi = NILFS_SB(sb);
691 sb->s_magic = le16_to_cpu(sbp->s_magic);
693 /* FS independent flags */
694 #ifdef NILFS_ATIME_DISABLE
695 sb->s_flags |= MS_NOATIME;
696 #endif
698 nilfs_set_default_options(sbi, sbp);
700 sbi->s_resuid = le16_to_cpu(sbp->s_def_resuid);
701 sbi->s_resgid = le16_to_cpu(sbp->s_def_resgid);
702 sbi->s_interval = le32_to_cpu(sbp->s_c_interval);
703 sbi->s_watermark = le32_to_cpu(sbp->s_c_block_max);
705 return !parse_options(data, sb, 0) ? -EINVAL : 0 ;
708 int nilfs_check_feature_compatibility(struct super_block *sb,
709 struct nilfs_super_block *sbp)
711 __u64 features;
713 features = le64_to_cpu(sbp->s_feature_incompat) &
714 ~NILFS_FEATURE_INCOMPAT_SUPP;
715 if (features) {
716 printk(KERN_ERR "NILFS: couldn't mount because of unsupported "
717 "optional features (%llx)\n",
718 (unsigned long long)features);
719 return -EINVAL;
721 features = le64_to_cpu(sbp->s_feature_compat_ro) &
722 ~NILFS_FEATURE_COMPAT_RO_SUPP;
723 if (!(sb->s_flags & MS_RDONLY) && features) {
724 printk(KERN_ERR "NILFS: couldn't mount RDWR because of "
725 "unsupported optional features (%llx)\n",
726 (unsigned long long)features);
727 return -EINVAL;
729 return 0;
732 static int nilfs_get_root_dentry(struct super_block *sb,
733 struct nilfs_root *root,
734 struct dentry **root_dentry)
736 struct inode *inode;
737 struct dentry *dentry;
738 int ret = 0;
740 inode = nilfs_iget(sb, root, NILFS_ROOT_INO);
741 if (IS_ERR(inode)) {
742 printk(KERN_ERR "NILFS: get root inode failed\n");
743 ret = PTR_ERR(inode);
744 goto out;
746 if (!S_ISDIR(inode->i_mode) || !inode->i_blocks || !inode->i_size) {
747 iput(inode);
748 printk(KERN_ERR "NILFS: corrupt root inode.\n");
749 ret = -EINVAL;
750 goto out;
753 if (root->cno == NILFS_CPTREE_CURRENT_CNO) {
754 dentry = d_find_alias(inode);
755 if (!dentry) {
756 dentry = d_alloc_root(inode);
757 if (!dentry) {
758 iput(inode);
759 ret = -ENOMEM;
760 goto failed_dentry;
762 } else {
763 iput(inode);
765 } else {
766 dentry = d_obtain_alias(inode);
767 if (IS_ERR(dentry)) {
768 ret = PTR_ERR(dentry);
769 goto failed_dentry;
772 *root_dentry = dentry;
773 out:
774 return ret;
776 failed_dentry:
777 printk(KERN_ERR "NILFS: get root dentry failed\n");
778 goto out;
781 static int nilfs_attach_snapshot(struct super_block *s, __u64 cno,
782 struct dentry **root_dentry)
784 struct the_nilfs *nilfs = NILFS_SB(s)->s_nilfs;
785 struct nilfs_root *root;
786 int ret;
788 down_read(&nilfs->ns_segctor_sem);
789 ret = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile, cno);
790 up_read(&nilfs->ns_segctor_sem);
791 if (ret < 0) {
792 ret = (ret == -ENOENT) ? -EINVAL : ret;
793 goto out;
794 } else if (!ret) {
795 printk(KERN_ERR "NILFS: The specified checkpoint is "
796 "not a snapshot (checkpoint number=%llu).\n",
797 (unsigned long long)cno);
798 ret = -EINVAL;
799 goto out;
802 ret = nilfs_attach_checkpoint(NILFS_SB(s), cno, false, &root);
803 if (ret) {
804 printk(KERN_ERR "NILFS: error loading snapshot "
805 "(checkpoint number=%llu).\n",
806 (unsigned long long)cno);
807 goto out;
809 ret = nilfs_get_root_dentry(s, root, root_dentry);
810 nilfs_put_root(root);
811 out:
812 return ret;
815 static int nilfs_tree_was_touched(struct dentry *root_dentry)
817 return atomic_read(&root_dentry->d_count) > 1;
821 * nilfs_try_to_shrink_tree() - try to shrink dentries of a checkpoint
822 * @root_dentry: root dentry of the tree to be shrunk
824 * This function returns true if the tree was in-use.
826 static int nilfs_try_to_shrink_tree(struct dentry *root_dentry)
828 if (have_submounts(root_dentry))
829 return true;
830 shrink_dcache_parent(root_dentry);
831 return nilfs_tree_was_touched(root_dentry);
835 * nilfs_fill_super() - initialize a super block instance
836 * @sb: super_block
837 * @data: mount options
838 * @silent: silent mode flag
840 * This function is called exclusively by nilfs->ns_mount_mutex.
841 * So, the recovery process is protected from other simultaneous mounts.
843 static int
844 nilfs_fill_super(struct super_block *sb, void *data, int silent)
846 struct the_nilfs *nilfs;
847 struct nilfs_sb_info *sbi;
848 struct nilfs_root *fsroot;
849 __u64 cno;
850 int err;
852 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
853 if (!sbi)
854 return -ENOMEM;
856 sb->s_fs_info = sbi;
857 sbi->s_super = sb;
859 nilfs = alloc_nilfs(sb->s_bdev);
860 if (!nilfs) {
861 err = -ENOMEM;
862 goto failed_sbi;
864 sbi->s_nilfs = nilfs;
866 err = init_nilfs(nilfs, sbi, (char *)data);
867 if (err)
868 goto failed_nilfs;
870 spin_lock_init(&sbi->s_inode_lock);
871 INIT_LIST_HEAD(&sbi->s_dirty_files);
874 * Following initialization is overlapped because
875 * nilfs_sb_info structure has been cleared at the beginning.
876 * But we reserve them to keep our interest and make ready
877 * for the future change.
879 get_random_bytes(&sbi->s_next_generation,
880 sizeof(sbi->s_next_generation));
881 spin_lock_init(&sbi->s_next_gen_lock);
883 sb->s_op = &nilfs_sops;
884 sb->s_export_op = &nilfs_export_ops;
885 sb->s_root = NULL;
886 sb->s_time_gran = 1;
887 sb->s_bdi = nilfs->ns_bdi;
889 err = load_nilfs(nilfs, sbi);
890 if (err)
891 goto failed_nilfs;
893 cno = nilfs_last_cno(nilfs);
894 err = nilfs_attach_checkpoint(sbi, cno, true, &fsroot);
895 if (err) {
896 printk(KERN_ERR "NILFS: error loading last checkpoint "
897 "(checkpoint number=%llu).\n", (unsigned long long)cno);
898 goto failed_nilfs;
901 if (!(sb->s_flags & MS_RDONLY)) {
902 err = nilfs_attach_segment_constructor(sbi, fsroot);
903 if (err)
904 goto failed_checkpoint;
907 err = nilfs_get_root_dentry(sb, fsroot, &sb->s_root);
908 if (err)
909 goto failed_segctor;
911 nilfs_put_root(fsroot);
913 if (!(sb->s_flags & MS_RDONLY)) {
914 down_write(&nilfs->ns_sem);
915 nilfs_setup_super(sbi);
916 up_write(&nilfs->ns_sem);
919 return 0;
921 failed_segctor:
922 nilfs_detach_segment_constructor(sbi);
924 failed_checkpoint:
925 nilfs_put_root(fsroot);
927 failed_nilfs:
928 destroy_nilfs(nilfs);
930 failed_sbi:
931 sb->s_fs_info = NULL;
932 kfree(sbi);
933 return err;
936 static int nilfs_remount(struct super_block *sb, int *flags, char *data)
938 struct nilfs_sb_info *sbi = NILFS_SB(sb);
939 struct the_nilfs *nilfs = sbi->s_nilfs;
940 unsigned long old_sb_flags;
941 struct nilfs_mount_options old_opts;
942 int err;
944 old_sb_flags = sb->s_flags;
945 old_opts.mount_opt = sbi->s_mount_opt;
947 if (!parse_options(data, sb, 1)) {
948 err = -EINVAL;
949 goto restore_opts;
951 sb->s_flags = (sb->s_flags & ~MS_POSIXACL);
953 err = -EINVAL;
955 if (!nilfs_valid_fs(nilfs)) {
956 printk(KERN_WARNING "NILFS (device %s): couldn't "
957 "remount because the filesystem is in an "
958 "incomplete recovery state.\n", sb->s_id);
959 goto restore_opts;
962 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
963 goto out;
964 if (*flags & MS_RDONLY) {
965 /* Shutting down the segment constructor */
966 nilfs_detach_segment_constructor(sbi);
967 sb->s_flags |= MS_RDONLY;
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);
974 nilfs_cleanup_super(sbi);
975 up_write(&nilfs->ns_sem);
976 } else {
977 __u64 features;
978 struct nilfs_root *root;
981 * Mounting a RDONLY partition read-write, so reread and
982 * store the current valid flag. (It may have been changed
983 * by fsck since we originally mounted the partition.)
985 down_read(&nilfs->ns_sem);
986 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
987 ~NILFS_FEATURE_COMPAT_RO_SUPP;
988 up_read(&nilfs->ns_sem);
989 if (features) {
990 printk(KERN_WARNING "NILFS (device %s): couldn't "
991 "remount RDWR because of unsupported optional "
992 "features (%llx)\n",
993 sb->s_id, (unsigned long long)features);
994 err = -EROFS;
995 goto restore_opts;
998 sb->s_flags &= ~MS_RDONLY;
1000 root = NILFS_I(sb->s_root->d_inode)->i_root;
1001 err = nilfs_attach_segment_constructor(sbi, root);
1002 if (err)
1003 goto restore_opts;
1005 down_write(&nilfs->ns_sem);
1006 nilfs_setup_super(sbi);
1007 up_write(&nilfs->ns_sem);
1009 out:
1010 return 0;
1012 restore_opts:
1013 sb->s_flags = old_sb_flags;
1014 sbi->s_mount_opt = old_opts.mount_opt;
1015 return err;
1018 struct nilfs_super_data {
1019 struct block_device *bdev;
1020 struct nilfs_sb_info *sbi;
1021 __u64 cno;
1022 int flags;
1026 * nilfs_identify - pre-read mount options needed to identify mount instance
1027 * @data: mount options
1028 * @sd: nilfs_super_data
1030 static int nilfs_identify(char *data, struct nilfs_super_data *sd)
1032 char *p, *options = data;
1033 substring_t args[MAX_OPT_ARGS];
1034 int option, token;
1035 int ret = 0;
1037 do {
1038 p = strsep(&options, ",");
1039 if (p != NULL && *p) {
1040 token = match_token(p, tokens, args);
1041 if (token == Opt_snapshot) {
1042 if (!(sd->flags & MS_RDONLY))
1043 ret++;
1044 else {
1045 ret = match_int(&args[0], &option);
1046 if (!ret) {
1047 if (option > 0)
1048 sd->cno = option;
1049 else
1050 ret++;
1054 if (ret)
1055 printk(KERN_ERR
1056 "NILFS: invalid mount option: %s\n", p);
1058 if (!options)
1059 break;
1060 BUG_ON(options == data);
1061 *(options - 1) = ',';
1062 } while (!ret);
1063 return ret;
1066 static int nilfs_set_bdev_super(struct super_block *s, void *data)
1068 s->s_bdev = data;
1069 s->s_dev = s->s_bdev->bd_dev;
1070 return 0;
1073 static int nilfs_test_bdev_super(struct super_block *s, void *data)
1075 return (void *)s->s_bdev == data;
1078 static int
1079 nilfs_get_sb(struct file_system_type *fs_type, int flags,
1080 const char *dev_name, void *data, struct vfsmount *mnt)
1082 struct nilfs_super_data sd;
1083 struct super_block *s;
1084 fmode_t mode = FMODE_READ;
1085 struct dentry *root_dentry;
1086 int err, s_new = false;
1088 if (!(flags & MS_RDONLY))
1089 mode |= FMODE_WRITE;
1091 sd.bdev = open_bdev_exclusive(dev_name, mode, fs_type);
1092 if (IS_ERR(sd.bdev))
1093 return PTR_ERR(sd.bdev);
1095 sd.cno = 0;
1096 sd.flags = flags;
1097 if (nilfs_identify((char *)data, &sd)) {
1098 err = -EINVAL;
1099 goto failed;
1102 s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, sd.bdev);
1103 if (IS_ERR(s)) {
1104 err = PTR_ERR(s);
1105 goto failed;
1108 if (!s->s_root) {
1109 char b[BDEVNAME_SIZE];
1111 s_new = true;
1113 /* New superblock instance created */
1114 s->s_flags = flags;
1115 s->s_mode = mode;
1116 strlcpy(s->s_id, bdevname(sd.bdev, b), sizeof(s->s_id));
1117 sb_set_blocksize(s, block_size(sd.bdev));
1119 err = nilfs_fill_super(s, data, flags & MS_SILENT ? 1 : 0);
1120 if (err)
1121 goto failed_super;
1123 s->s_flags |= MS_ACTIVE;
1124 } else if (!sd.cno) {
1125 int busy = false;
1127 if (nilfs_tree_was_touched(s->s_root)) {
1128 busy = nilfs_try_to_shrink_tree(s->s_root);
1129 if (busy && (flags ^ s->s_flags) & MS_RDONLY) {
1130 printk(KERN_ERR "NILFS: the device already "
1131 "has a %s mount.\n",
1132 (s->s_flags & MS_RDONLY) ?
1133 "read-only" : "read/write");
1134 err = -EBUSY;
1135 goto failed_super;
1138 if (!busy) {
1140 * Try remount to setup mount states if the current
1141 * tree is not mounted and only snapshots use this sb.
1143 err = nilfs_remount(s, &flags, data);
1144 if (err)
1145 goto failed_super;
1149 if (sd.cno) {
1150 err = nilfs_attach_snapshot(s, sd.cno, &root_dentry);
1151 if (err)
1152 goto failed_super;
1153 } else {
1154 root_dentry = dget(s->s_root);
1157 if (!s_new)
1158 close_bdev_exclusive(sd.bdev, mode);
1160 mnt->mnt_sb = s;
1161 mnt->mnt_root = root_dentry;
1162 return 0;
1164 failed_super:
1165 deactivate_locked_super(s);
1167 failed:
1168 if (!s_new)
1169 close_bdev_exclusive(sd.bdev, mode);
1170 return err;
1173 struct file_system_type nilfs_fs_type = {
1174 .owner = THIS_MODULE,
1175 .name = "nilfs2",
1176 .get_sb = nilfs_get_sb,
1177 .kill_sb = kill_block_super,
1178 .fs_flags = FS_REQUIRES_DEV,
1181 static void nilfs_inode_init_once(void *obj)
1183 struct nilfs_inode_info *ii = obj;
1185 INIT_LIST_HEAD(&ii->i_dirty);
1186 #ifdef CONFIG_NILFS_XATTR
1187 init_rwsem(&ii->xattr_sem);
1188 #endif
1189 nilfs_btnode_cache_init_once(&ii->i_btnode_cache);
1190 ii->i_bmap = &ii->i_bmap_data;
1191 inode_init_once(&ii->vfs_inode);
1194 static void nilfs_segbuf_init_once(void *obj)
1196 memset(obj, 0, sizeof(struct nilfs_segment_buffer));
1199 static void nilfs_destroy_cachep(void)
1201 if (nilfs_inode_cachep)
1202 kmem_cache_destroy(nilfs_inode_cachep);
1203 if (nilfs_transaction_cachep)
1204 kmem_cache_destroy(nilfs_transaction_cachep);
1205 if (nilfs_segbuf_cachep)
1206 kmem_cache_destroy(nilfs_segbuf_cachep);
1207 if (nilfs_btree_path_cache)
1208 kmem_cache_destroy(nilfs_btree_path_cache);
1211 static int __init nilfs_init_cachep(void)
1213 nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache",
1214 sizeof(struct nilfs_inode_info), 0,
1215 SLAB_RECLAIM_ACCOUNT, nilfs_inode_init_once);
1216 if (!nilfs_inode_cachep)
1217 goto fail;
1219 nilfs_transaction_cachep = kmem_cache_create("nilfs2_transaction_cache",
1220 sizeof(struct nilfs_transaction_info), 0,
1221 SLAB_RECLAIM_ACCOUNT, NULL);
1222 if (!nilfs_transaction_cachep)
1223 goto fail;
1225 nilfs_segbuf_cachep = kmem_cache_create("nilfs2_segbuf_cache",
1226 sizeof(struct nilfs_segment_buffer), 0,
1227 SLAB_RECLAIM_ACCOUNT, nilfs_segbuf_init_once);
1228 if (!nilfs_segbuf_cachep)
1229 goto fail;
1231 nilfs_btree_path_cache = kmem_cache_create("nilfs2_btree_path_cache",
1232 sizeof(struct nilfs_btree_path) * NILFS_BTREE_LEVEL_MAX,
1233 0, 0, NULL);
1234 if (!nilfs_btree_path_cache)
1235 goto fail;
1237 return 0;
1239 fail:
1240 nilfs_destroy_cachep();
1241 return -ENOMEM;
1244 static int __init init_nilfs_fs(void)
1246 int err;
1248 err = nilfs_init_cachep();
1249 if (err)
1250 goto fail;
1252 err = register_filesystem(&nilfs_fs_type);
1253 if (err)
1254 goto free_cachep;
1256 printk(KERN_INFO "NILFS version 2 loaded\n");
1257 return 0;
1259 free_cachep:
1260 nilfs_destroy_cachep();
1261 fail:
1262 return err;
1265 static void __exit exit_nilfs_fs(void)
1267 nilfs_destroy_cachep();
1268 unregister_filesystem(&nilfs_fs_type);
1271 module_init(init_nilfs_fs)
1272 module_exit(exit_nilfs_fs)