xref: /openbmc/linux/fs/nilfs2/super.c (revision 4800cd83)
1 /*
2  * super.c - NILFS module and super block management.
3  *
4  * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
5  *
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.
10  *
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.
15  *
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
19  *
20  * Written by Ryusuke Konishi <ryusuke@osrg.net>
21  */
22 /*
23  *  linux/fs/ext2/super.c
24  *
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)
29  *
30  *  from
31  *
32  *  linux/fs/minix/inode.c
33  *
34  *  Copyright (C) 1991, 1992  Linus Torvalds
35  *
36  *  Big-endian to little-endian byte-swapping/bitmaps by
37  *        David S. Miller (davem@caip.rutgers.edu), 1995
38  */
39 
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/seq_file.h>
51 #include <linux/mount.h>
52 #include "nilfs.h"
53 #include "export.h"
54 #include "mdt.h"
55 #include "alloc.h"
56 #include "btree.h"
57 #include "btnode.h"
58 #include "page.h"
59 #include "cpfile.h"
60 #include "ifile.h"
61 #include "dat.h"
62 #include "segment.h"
63 #include "segbuf.h"
64 
65 MODULE_AUTHOR("NTT Corp.");
66 MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem "
67 		   "(NILFS)");
68 MODULE_LICENSE("GPL");
69 
70 static struct kmem_cache *nilfs_inode_cachep;
71 struct kmem_cache *nilfs_transaction_cachep;
72 struct kmem_cache *nilfs_segbuf_cachep;
73 struct kmem_cache *nilfs_btree_path_cache;
74 
75 static int nilfs_setup_super(struct nilfs_sb_info *sbi, int is_mount);
76 static int nilfs_remount(struct super_block *sb, int *flags, char *data);
77 
78 static void nilfs_set_error(struct nilfs_sb_info *sbi)
79 {
80 	struct the_nilfs *nilfs = sbi->s_nilfs;
81 	struct nilfs_super_block **sbp;
82 
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);
92 		}
93 	}
94 	up_write(&nilfs->ns_sem);
95 }
96 
97 /**
98  * nilfs_error() - report failure condition on a filesystem
99  *
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.
105  *
106  * The segment constructor must not call this function because it can
107  * kill itself.
108  */
109 void nilfs_error(struct super_block *sb, const char *function,
110 		 const char *fmt, ...)
111 {
112 	struct nilfs_sb_info *sbi = NILFS_SB(sb);
113 	struct va_format vaf;
114 	va_list args;
115 
116 	va_start(args, fmt);
117 
118 	vaf.fmt = fmt;
119 	vaf.va = &args;
120 
121 	printk(KERN_CRIT "NILFS error (device %s): %s: %pV\n",
122 	       sb->s_id, function, &vaf);
123 
124 	va_end(args);
125 
126 	if (!(sb->s_flags & MS_RDONLY)) {
127 		nilfs_set_error(sbi);
128 
129 		if (nilfs_test_opt(sbi, ERRORS_RO)) {
130 			printk(KERN_CRIT "Remounting filesystem read-only\n");
131 			sb->s_flags |= MS_RDONLY;
132 		}
133 	}
134 
135 	if (nilfs_test_opt(sbi, ERRORS_PANIC))
136 		panic("NILFS (device %s): panic forced after error\n",
137 		      sb->s_id);
138 }
139 
140 void nilfs_warning(struct super_block *sb, const char *function,
141 		   const char *fmt, ...)
142 {
143 	struct va_format vaf;
144 	va_list args;
145 
146 	va_start(args, fmt);
147 
148 	vaf.fmt = fmt;
149 	vaf.va = &args;
150 
151 	printk(KERN_WARNING "NILFS warning (device %s): %s: %pV\n",
152 	       sb->s_id, function, &vaf);
153 
154 	va_end(args);
155 }
156 
157 
158 struct inode *nilfs_alloc_inode(struct super_block *sb)
159 {
160 	struct nilfs_inode_info *ii;
161 
162 	ii = kmem_cache_alloc(nilfs_inode_cachep, GFP_NOFS);
163 	if (!ii)
164 		return NULL;
165 	ii->i_bh = NULL;
166 	ii->i_state = 0;
167 	ii->i_cno = 0;
168 	ii->vfs_inode.i_version = 1;
169 	nilfs_btnode_cache_init(&ii->i_btnode_cache, sb->s_bdi);
170 	return &ii->vfs_inode;
171 }
172 
173 static void nilfs_i_callback(struct rcu_head *head)
174 {
175 	struct inode *inode = container_of(head, struct inode, i_rcu);
176 	struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
177 
178 	INIT_LIST_HEAD(&inode->i_dentry);
179 
180 	if (mdi) {
181 		kfree(mdi->mi_bgl); /* kfree(NULL) is safe */
182 		kfree(mdi);
183 	}
184 	kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode));
185 }
186 
187 void nilfs_destroy_inode(struct inode *inode)
188 {
189 	call_rcu(&inode->i_rcu, nilfs_i_callback);
190 }
191 
192 static int nilfs_sync_super(struct nilfs_sb_info *sbi, int flag)
193 {
194 	struct the_nilfs *nilfs = sbi->s_nilfs;
195 	int err;
196 
197  retry:
198 	set_buffer_dirty(nilfs->ns_sbh[0]);
199 	if (nilfs_test_opt(sbi, BARRIER)) {
200 		err = __sync_dirty_buffer(nilfs->ns_sbh[0],
201 					  WRITE_SYNC | WRITE_FLUSH_FUA);
202 	} else {
203 		err = sync_dirty_buffer(nilfs->ns_sbh[0]);
204 	}
205 
206 	if (unlikely(err)) {
207 		printk(KERN_ERR
208 		       "NILFS: unable to write superblock (err=%d)\n", err);
209 		if (err == -EIO && nilfs->ns_sbh[1]) {
210 			/*
211 			 * sbp[0] points to newer log than sbp[1],
212 			 * so copy sbp[0] to sbp[1] to take over sbp[0].
213 			 */
214 			memcpy(nilfs->ns_sbp[1], nilfs->ns_sbp[0],
215 			       nilfs->ns_sbsize);
216 			nilfs_fall_back_super_block(nilfs);
217 			goto retry;
218 		}
219 	} else {
220 		struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
221 
222 		nilfs->ns_sbwcount++;
223 
224 		/*
225 		 * The latest segment becomes trailable from the position
226 		 * written in superblock.
227 		 */
228 		clear_nilfs_discontinued(nilfs);
229 
230 		/* update GC protection for recent segments */
231 		if (nilfs->ns_sbh[1]) {
232 			if (flag == NILFS_SB_COMMIT_ALL) {
233 				set_buffer_dirty(nilfs->ns_sbh[1]);
234 				if (sync_dirty_buffer(nilfs->ns_sbh[1]) < 0)
235 					goto out;
236 			}
237 			if (le64_to_cpu(nilfs->ns_sbp[1]->s_last_cno) <
238 			    le64_to_cpu(nilfs->ns_sbp[0]->s_last_cno))
239 				sbp = nilfs->ns_sbp[1];
240 		}
241 
242 		spin_lock(&nilfs->ns_last_segment_lock);
243 		nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq);
244 		spin_unlock(&nilfs->ns_last_segment_lock);
245 	}
246  out:
247 	return err;
248 }
249 
250 void nilfs_set_log_cursor(struct nilfs_super_block *sbp,
251 			  struct the_nilfs *nilfs)
252 {
253 	sector_t nfreeblocks;
254 
255 	/* nilfs->ns_sem must be locked by the caller. */
256 	nilfs_count_free_blocks(nilfs, &nfreeblocks);
257 	sbp->s_free_blocks_count = cpu_to_le64(nfreeblocks);
258 
259 	spin_lock(&nilfs->ns_last_segment_lock);
260 	sbp->s_last_seq = cpu_to_le64(nilfs->ns_last_seq);
261 	sbp->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg);
262 	sbp->s_last_cno = cpu_to_le64(nilfs->ns_last_cno);
263 	spin_unlock(&nilfs->ns_last_segment_lock);
264 }
265 
266 struct nilfs_super_block **nilfs_prepare_super(struct nilfs_sb_info *sbi,
267 					       int flip)
268 {
269 	struct the_nilfs *nilfs = sbi->s_nilfs;
270 	struct nilfs_super_block **sbp = nilfs->ns_sbp;
271 
272 	/* nilfs->ns_sem must be locked by the caller. */
273 	if (sbp[0]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
274 		if (sbp[1] &&
275 		    sbp[1]->s_magic == cpu_to_le16(NILFS_SUPER_MAGIC)) {
276 			memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
277 		} else {
278 			printk(KERN_CRIT "NILFS: superblock broke on dev %s\n",
279 			       sbi->s_super->s_id);
280 			return NULL;
281 		}
282 	} else if (sbp[1] &&
283 		   sbp[1]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
284 			memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
285 	}
286 
287 	if (flip && sbp[1])
288 		nilfs_swap_super_block(nilfs);
289 
290 	return sbp;
291 }
292 
293 int nilfs_commit_super(struct nilfs_sb_info *sbi, int flag)
294 {
295 	struct the_nilfs *nilfs = sbi->s_nilfs;
296 	struct nilfs_super_block **sbp = nilfs->ns_sbp;
297 	time_t t;
298 
299 	/* nilfs->ns_sem must be locked by the caller. */
300 	t = get_seconds();
301 	nilfs->ns_sbwtime = t;
302 	sbp[0]->s_wtime = cpu_to_le64(t);
303 	sbp[0]->s_sum = 0;
304 	sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
305 					     (unsigned char *)sbp[0],
306 					     nilfs->ns_sbsize));
307 	if (flag == NILFS_SB_COMMIT_ALL && sbp[1]) {
308 		sbp[1]->s_wtime = sbp[0]->s_wtime;
309 		sbp[1]->s_sum = 0;
310 		sbp[1]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
311 					    (unsigned char *)sbp[1],
312 					    nilfs->ns_sbsize));
313 	}
314 	clear_nilfs_sb_dirty(nilfs);
315 	return nilfs_sync_super(sbi, flag);
316 }
317 
318 /**
319  * nilfs_cleanup_super() - write filesystem state for cleanup
320  * @sbi: nilfs_sb_info to be unmounted or degraded to read-only
321  *
322  * This function restores state flags in the on-disk super block.
323  * This will set "clean" flag (i.e. NILFS_VALID_FS) unless the
324  * filesystem was not clean previously.
325  */
326 int nilfs_cleanup_super(struct nilfs_sb_info *sbi)
327 {
328 	struct nilfs_super_block **sbp;
329 	int flag = NILFS_SB_COMMIT;
330 	int ret = -EIO;
331 
332 	sbp = nilfs_prepare_super(sbi, 0);
333 	if (sbp) {
334 		sbp[0]->s_state = cpu_to_le16(sbi->s_nilfs->ns_mount_state);
335 		nilfs_set_log_cursor(sbp[0], sbi->s_nilfs);
336 		if (sbp[1] && sbp[0]->s_last_cno == sbp[1]->s_last_cno) {
337 			/*
338 			 * make the "clean" flag also to the opposite
339 			 * super block if both super blocks point to
340 			 * the same checkpoint.
341 			 */
342 			sbp[1]->s_state = sbp[0]->s_state;
343 			flag = NILFS_SB_COMMIT_ALL;
344 		}
345 		ret = nilfs_commit_super(sbi, flag);
346 	}
347 	return ret;
348 }
349 
350 static void nilfs_put_super(struct super_block *sb)
351 {
352 	struct nilfs_sb_info *sbi = NILFS_SB(sb);
353 	struct the_nilfs *nilfs = sbi->s_nilfs;
354 
355 	nilfs_detach_segment_constructor(sbi);
356 
357 	if (!(sb->s_flags & MS_RDONLY)) {
358 		down_write(&nilfs->ns_sem);
359 		nilfs_cleanup_super(sbi);
360 		up_write(&nilfs->ns_sem);
361 	}
362 
363 	iput(nilfs->ns_sufile);
364 	iput(nilfs->ns_cpfile);
365 	iput(nilfs->ns_dat);
366 
367 	destroy_nilfs(nilfs);
368 	sbi->s_super = NULL;
369 	sb->s_fs_info = NULL;
370 	kfree(sbi);
371 }
372 
373 static int nilfs_sync_fs(struct super_block *sb, int wait)
374 {
375 	struct nilfs_sb_info *sbi = NILFS_SB(sb);
376 	struct the_nilfs *nilfs = sbi->s_nilfs;
377 	struct nilfs_super_block **sbp;
378 	int err = 0;
379 
380 	/* This function is called when super block should be written back */
381 	if (wait)
382 		err = nilfs_construct_segment(sb);
383 
384 	down_write(&nilfs->ns_sem);
385 	if (nilfs_sb_dirty(nilfs)) {
386 		sbp = nilfs_prepare_super(sbi, nilfs_sb_will_flip(nilfs));
387 		if (likely(sbp)) {
388 			nilfs_set_log_cursor(sbp[0], nilfs);
389 			nilfs_commit_super(sbi, NILFS_SB_COMMIT);
390 		}
391 	}
392 	up_write(&nilfs->ns_sem);
393 
394 	return err;
395 }
396 
397 int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno, int curr_mnt,
398 			    struct nilfs_root **rootp)
399 {
400 	struct the_nilfs *nilfs = sbi->s_nilfs;
401 	struct nilfs_root *root;
402 	struct nilfs_checkpoint *raw_cp;
403 	struct buffer_head *bh_cp;
404 	int err = -ENOMEM;
405 
406 	root = nilfs_find_or_create_root(
407 		nilfs, curr_mnt ? NILFS_CPTREE_CURRENT_CNO : cno);
408 	if (!root)
409 		return err;
410 
411 	if (root->ifile)
412 		goto reuse; /* already attached checkpoint */
413 
414 	down_read(&nilfs->ns_segctor_sem);
415 	err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp,
416 					  &bh_cp);
417 	up_read(&nilfs->ns_segctor_sem);
418 	if (unlikely(err)) {
419 		if (err == -ENOENT || err == -EINVAL) {
420 			printk(KERN_ERR
421 			       "NILFS: Invalid checkpoint "
422 			       "(checkpoint number=%llu)\n",
423 			       (unsigned long long)cno);
424 			err = -EINVAL;
425 		}
426 		goto failed;
427 	}
428 
429 	err = nilfs_ifile_read(sbi->s_super, root, nilfs->ns_inode_size,
430 			       &raw_cp->cp_ifile_inode, &root->ifile);
431 	if (err)
432 		goto failed_bh;
433 
434 	atomic_set(&root->inodes_count, le64_to_cpu(raw_cp->cp_inodes_count));
435 	atomic_set(&root->blocks_count, le64_to_cpu(raw_cp->cp_blocks_count));
436 
437 	nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
438 
439  reuse:
440 	*rootp = root;
441 	return 0;
442 
443  failed_bh:
444 	nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
445  failed:
446 	nilfs_put_root(root);
447 
448 	return err;
449 }
450 
451 static int nilfs_freeze(struct super_block *sb)
452 {
453 	struct nilfs_sb_info *sbi = NILFS_SB(sb);
454 	struct the_nilfs *nilfs = sbi->s_nilfs;
455 	int err;
456 
457 	if (sb->s_flags & MS_RDONLY)
458 		return 0;
459 
460 	/* Mark super block clean */
461 	down_write(&nilfs->ns_sem);
462 	err = nilfs_cleanup_super(sbi);
463 	up_write(&nilfs->ns_sem);
464 	return err;
465 }
466 
467 static int nilfs_unfreeze(struct super_block *sb)
468 {
469 	struct nilfs_sb_info *sbi = NILFS_SB(sb);
470 	struct the_nilfs *nilfs = sbi->s_nilfs;
471 
472 	if (sb->s_flags & MS_RDONLY)
473 		return 0;
474 
475 	down_write(&nilfs->ns_sem);
476 	nilfs_setup_super(sbi, false);
477 	up_write(&nilfs->ns_sem);
478 	return 0;
479 }
480 
481 static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
482 {
483 	struct super_block *sb = dentry->d_sb;
484 	struct nilfs_root *root = NILFS_I(dentry->d_inode)->i_root;
485 	struct the_nilfs *nilfs = root->nilfs;
486 	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
487 	unsigned long long blocks;
488 	unsigned long overhead;
489 	unsigned long nrsvblocks;
490 	sector_t nfreeblocks;
491 	int err;
492 
493 	/*
494 	 * Compute all of the segment blocks
495 	 *
496 	 * The blocks before first segment and after last segment
497 	 * are excluded.
498 	 */
499 	blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments
500 		- nilfs->ns_first_data_block;
501 	nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment;
502 
503 	/*
504 	 * Compute the overhead
505 	 *
506 	 * When distributing meta data blocks outside segment structure,
507 	 * We must count them as the overhead.
508 	 */
509 	overhead = 0;
510 
511 	err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
512 	if (unlikely(err))
513 		return err;
514 
515 	buf->f_type = NILFS_SUPER_MAGIC;
516 	buf->f_bsize = sb->s_blocksize;
517 	buf->f_blocks = blocks - overhead;
518 	buf->f_bfree = nfreeblocks;
519 	buf->f_bavail = (buf->f_bfree >= nrsvblocks) ?
520 		(buf->f_bfree - nrsvblocks) : 0;
521 	buf->f_files = atomic_read(&root->inodes_count);
522 	buf->f_ffree = 0; /* nilfs_count_free_inodes(sb); */
523 	buf->f_namelen = NILFS_NAME_LEN;
524 	buf->f_fsid.val[0] = (u32)id;
525 	buf->f_fsid.val[1] = (u32)(id >> 32);
526 
527 	return 0;
528 }
529 
530 static int nilfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
531 {
532 	struct super_block *sb = vfs->mnt_sb;
533 	struct nilfs_sb_info *sbi = NILFS_SB(sb);
534 	struct nilfs_root *root = NILFS_I(vfs->mnt_root->d_inode)->i_root;
535 
536 	if (!nilfs_test_opt(sbi, BARRIER))
537 		seq_puts(seq, ",nobarrier");
538 	if (root->cno != NILFS_CPTREE_CURRENT_CNO)
539 		seq_printf(seq, ",cp=%llu", (unsigned long long)root->cno);
540 	if (nilfs_test_opt(sbi, ERRORS_PANIC))
541 		seq_puts(seq, ",errors=panic");
542 	if (nilfs_test_opt(sbi, ERRORS_CONT))
543 		seq_puts(seq, ",errors=continue");
544 	if (nilfs_test_opt(sbi, STRICT_ORDER))
545 		seq_puts(seq, ",order=strict");
546 	if (nilfs_test_opt(sbi, NORECOVERY))
547 		seq_puts(seq, ",norecovery");
548 	if (nilfs_test_opt(sbi, DISCARD))
549 		seq_puts(seq, ",discard");
550 
551 	return 0;
552 }
553 
554 static const struct super_operations nilfs_sops = {
555 	.alloc_inode    = nilfs_alloc_inode,
556 	.destroy_inode  = nilfs_destroy_inode,
557 	.dirty_inode    = nilfs_dirty_inode,
558 	/* .write_inode    = nilfs_write_inode, */
559 	/* .put_inode      = nilfs_put_inode, */
560 	/* .drop_inode	  = nilfs_drop_inode, */
561 	.evict_inode    = nilfs_evict_inode,
562 	.put_super      = nilfs_put_super,
563 	/* .write_super    = nilfs_write_super, */
564 	.sync_fs        = nilfs_sync_fs,
565 	.freeze_fs	= nilfs_freeze,
566 	.unfreeze_fs	= nilfs_unfreeze,
567 	/* .write_super_lockfs */
568 	/* .unlockfs */
569 	.statfs         = nilfs_statfs,
570 	.remount_fs     = nilfs_remount,
571 	/* .umount_begin */
572 	.show_options = nilfs_show_options
573 };
574 
575 enum {
576 	Opt_err_cont, Opt_err_panic, Opt_err_ro,
577 	Opt_barrier, Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery,
578 	Opt_discard, Opt_nodiscard, Opt_err,
579 };
580 
581 static match_table_t tokens = {
582 	{Opt_err_cont, "errors=continue"},
583 	{Opt_err_panic, "errors=panic"},
584 	{Opt_err_ro, "errors=remount-ro"},
585 	{Opt_barrier, "barrier"},
586 	{Opt_nobarrier, "nobarrier"},
587 	{Opt_snapshot, "cp=%u"},
588 	{Opt_order, "order=%s"},
589 	{Opt_norecovery, "norecovery"},
590 	{Opt_discard, "discard"},
591 	{Opt_nodiscard, "nodiscard"},
592 	{Opt_err, NULL}
593 };
594 
595 static int parse_options(char *options, struct super_block *sb, int is_remount)
596 {
597 	struct nilfs_sb_info *sbi = NILFS_SB(sb);
598 	char *p;
599 	substring_t args[MAX_OPT_ARGS];
600 
601 	if (!options)
602 		return 1;
603 
604 	while ((p = strsep(&options, ",")) != NULL) {
605 		int token;
606 		if (!*p)
607 			continue;
608 
609 		token = match_token(p, tokens, args);
610 		switch (token) {
611 		case Opt_barrier:
612 			nilfs_set_opt(sbi, BARRIER);
613 			break;
614 		case Opt_nobarrier:
615 			nilfs_clear_opt(sbi, BARRIER);
616 			break;
617 		case Opt_order:
618 			if (strcmp(args[0].from, "relaxed") == 0)
619 				/* Ordered data semantics */
620 				nilfs_clear_opt(sbi, STRICT_ORDER);
621 			else if (strcmp(args[0].from, "strict") == 0)
622 				/* Strict in-order semantics */
623 				nilfs_set_opt(sbi, STRICT_ORDER);
624 			else
625 				return 0;
626 			break;
627 		case Opt_err_panic:
628 			nilfs_write_opt(sbi, ERROR_MODE, ERRORS_PANIC);
629 			break;
630 		case Opt_err_ro:
631 			nilfs_write_opt(sbi, ERROR_MODE, ERRORS_RO);
632 			break;
633 		case Opt_err_cont:
634 			nilfs_write_opt(sbi, ERROR_MODE, ERRORS_CONT);
635 			break;
636 		case Opt_snapshot:
637 			if (is_remount) {
638 				printk(KERN_ERR
639 				       "NILFS: \"%s\" option is invalid "
640 				       "for remount.\n", p);
641 				return 0;
642 			}
643 			break;
644 		case Opt_norecovery:
645 			nilfs_set_opt(sbi, NORECOVERY);
646 			break;
647 		case Opt_discard:
648 			nilfs_set_opt(sbi, DISCARD);
649 			break;
650 		case Opt_nodiscard:
651 			nilfs_clear_opt(sbi, DISCARD);
652 			break;
653 		default:
654 			printk(KERN_ERR
655 			       "NILFS: Unrecognized mount option \"%s\"\n", p);
656 			return 0;
657 		}
658 	}
659 	return 1;
660 }
661 
662 static inline void
663 nilfs_set_default_options(struct nilfs_sb_info *sbi,
664 			  struct nilfs_super_block *sbp)
665 {
666 	sbi->s_mount_opt =
667 		NILFS_MOUNT_ERRORS_RO | NILFS_MOUNT_BARRIER;
668 }
669 
670 static int nilfs_setup_super(struct nilfs_sb_info *sbi, int is_mount)
671 {
672 	struct the_nilfs *nilfs = sbi->s_nilfs;
673 	struct nilfs_super_block **sbp;
674 	int max_mnt_count;
675 	int mnt_count;
676 
677 	/* nilfs->ns_sem must be locked by the caller. */
678 	sbp = nilfs_prepare_super(sbi, 0);
679 	if (!sbp)
680 		return -EIO;
681 
682 	if (!is_mount)
683 		goto skip_mount_setup;
684 
685 	max_mnt_count = le16_to_cpu(sbp[0]->s_max_mnt_count);
686 	mnt_count = le16_to_cpu(sbp[0]->s_mnt_count);
687 
688 	if (nilfs->ns_mount_state & NILFS_ERROR_FS) {
689 		printk(KERN_WARNING
690 		       "NILFS warning: mounting fs with errors\n");
691 #if 0
692 	} else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) {
693 		printk(KERN_WARNING
694 		       "NILFS warning: maximal mount count reached\n");
695 #endif
696 	}
697 	if (!max_mnt_count)
698 		sbp[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT);
699 
700 	sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1);
701 	sbp[0]->s_mtime = cpu_to_le64(get_seconds());
702 
703 skip_mount_setup:
704 	sbp[0]->s_state =
705 		cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS);
706 	/* synchronize sbp[1] with sbp[0] */
707 	if (sbp[1])
708 		memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
709 	return nilfs_commit_super(sbi, NILFS_SB_COMMIT_ALL);
710 }
711 
712 struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb,
713 						 u64 pos, int blocksize,
714 						 struct buffer_head **pbh)
715 {
716 	unsigned long long sb_index = pos;
717 	unsigned long offset;
718 
719 	offset = do_div(sb_index, blocksize);
720 	*pbh = sb_bread(sb, sb_index);
721 	if (!*pbh)
722 		return NULL;
723 	return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset);
724 }
725 
726 int nilfs_store_magic_and_option(struct super_block *sb,
727 				 struct nilfs_super_block *sbp,
728 				 char *data)
729 {
730 	struct nilfs_sb_info *sbi = NILFS_SB(sb);
731 
732 	sb->s_magic = le16_to_cpu(sbp->s_magic);
733 
734 	/* FS independent flags */
735 #ifdef NILFS_ATIME_DISABLE
736 	sb->s_flags |= MS_NOATIME;
737 #endif
738 
739 	nilfs_set_default_options(sbi, sbp);
740 
741 	sbi->s_resuid = le16_to_cpu(sbp->s_def_resuid);
742 	sbi->s_resgid = le16_to_cpu(sbp->s_def_resgid);
743 	sbi->s_interval = le32_to_cpu(sbp->s_c_interval);
744 	sbi->s_watermark = le32_to_cpu(sbp->s_c_block_max);
745 
746 	return !parse_options(data, sb, 0) ? -EINVAL : 0 ;
747 }
748 
749 int nilfs_check_feature_compatibility(struct super_block *sb,
750 				      struct nilfs_super_block *sbp)
751 {
752 	__u64 features;
753 
754 	features = le64_to_cpu(sbp->s_feature_incompat) &
755 		~NILFS_FEATURE_INCOMPAT_SUPP;
756 	if (features) {
757 		printk(KERN_ERR "NILFS: couldn't mount because of unsupported "
758 		       "optional features (%llx)\n",
759 		       (unsigned long long)features);
760 		return -EINVAL;
761 	}
762 	features = le64_to_cpu(sbp->s_feature_compat_ro) &
763 		~NILFS_FEATURE_COMPAT_RO_SUPP;
764 	if (!(sb->s_flags & MS_RDONLY) && features) {
765 		printk(KERN_ERR "NILFS: couldn't mount RDWR because of "
766 		       "unsupported optional features (%llx)\n",
767 		       (unsigned long long)features);
768 		return -EINVAL;
769 	}
770 	return 0;
771 }
772 
773 static int nilfs_get_root_dentry(struct super_block *sb,
774 				 struct nilfs_root *root,
775 				 struct dentry **root_dentry)
776 {
777 	struct inode *inode;
778 	struct dentry *dentry;
779 	int ret = 0;
780 
781 	inode = nilfs_iget(sb, root, NILFS_ROOT_INO);
782 	if (IS_ERR(inode)) {
783 		printk(KERN_ERR "NILFS: get root inode failed\n");
784 		ret = PTR_ERR(inode);
785 		goto out;
786 	}
787 	if (!S_ISDIR(inode->i_mode) || !inode->i_blocks || !inode->i_size) {
788 		iput(inode);
789 		printk(KERN_ERR "NILFS: corrupt root inode.\n");
790 		ret = -EINVAL;
791 		goto out;
792 	}
793 
794 	if (root->cno == NILFS_CPTREE_CURRENT_CNO) {
795 		dentry = d_find_alias(inode);
796 		if (!dentry) {
797 			dentry = d_alloc_root(inode);
798 			if (!dentry) {
799 				iput(inode);
800 				ret = -ENOMEM;
801 				goto failed_dentry;
802 			}
803 		} else {
804 			iput(inode);
805 		}
806 	} else {
807 		dentry = d_obtain_alias(inode);
808 		if (IS_ERR(dentry)) {
809 			ret = PTR_ERR(dentry);
810 			goto failed_dentry;
811 		}
812 	}
813 	*root_dentry = dentry;
814  out:
815 	return ret;
816 
817  failed_dentry:
818 	printk(KERN_ERR "NILFS: get root dentry failed\n");
819 	goto out;
820 }
821 
822 static int nilfs_attach_snapshot(struct super_block *s, __u64 cno,
823 				 struct dentry **root_dentry)
824 {
825 	struct the_nilfs *nilfs = NILFS_SB(s)->s_nilfs;
826 	struct nilfs_root *root;
827 	int ret;
828 
829 	down_read(&nilfs->ns_segctor_sem);
830 	ret = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile, cno);
831 	up_read(&nilfs->ns_segctor_sem);
832 	if (ret < 0) {
833 		ret = (ret == -ENOENT) ? -EINVAL : ret;
834 		goto out;
835 	} else if (!ret) {
836 		printk(KERN_ERR "NILFS: The specified checkpoint is "
837 		       "not a snapshot (checkpoint number=%llu).\n",
838 		       (unsigned long long)cno);
839 		ret = -EINVAL;
840 		goto out;
841 	}
842 
843 	ret = nilfs_attach_checkpoint(NILFS_SB(s), cno, false, &root);
844 	if (ret) {
845 		printk(KERN_ERR "NILFS: error loading snapshot "
846 		       "(checkpoint number=%llu).\n",
847 	       (unsigned long long)cno);
848 		goto out;
849 	}
850 	ret = nilfs_get_root_dentry(s, root, root_dentry);
851 	nilfs_put_root(root);
852  out:
853 	return ret;
854 }
855 
856 static int nilfs_tree_was_touched(struct dentry *root_dentry)
857 {
858 	return root_dentry->d_count > 1;
859 }
860 
861 /**
862  * nilfs_try_to_shrink_tree() - try to shrink dentries of a checkpoint
863  * @root_dentry: root dentry of the tree to be shrunk
864  *
865  * This function returns true if the tree was in-use.
866  */
867 static int nilfs_try_to_shrink_tree(struct dentry *root_dentry)
868 {
869 	if (have_submounts(root_dentry))
870 		return true;
871 	shrink_dcache_parent(root_dentry);
872 	return nilfs_tree_was_touched(root_dentry);
873 }
874 
875 int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno)
876 {
877 	struct the_nilfs *nilfs = NILFS_SB(sb)->s_nilfs;
878 	struct nilfs_root *root;
879 	struct inode *inode;
880 	struct dentry *dentry;
881 	int ret;
882 
883 	if (cno < 0 || cno > nilfs->ns_cno)
884 		return false;
885 
886 	if (cno >= nilfs_last_cno(nilfs))
887 		return true;	/* protect recent checkpoints */
888 
889 	ret = false;
890 	root = nilfs_lookup_root(NILFS_SB(sb)->s_nilfs, cno);
891 	if (root) {
892 		inode = nilfs_ilookup(sb, root, NILFS_ROOT_INO);
893 		if (inode) {
894 			dentry = d_find_alias(inode);
895 			if (dentry) {
896 				if (nilfs_tree_was_touched(dentry))
897 					ret = nilfs_try_to_shrink_tree(dentry);
898 				dput(dentry);
899 			}
900 			iput(inode);
901 		}
902 		nilfs_put_root(root);
903 	}
904 	return ret;
905 }
906 
907 /**
908  * nilfs_fill_super() - initialize a super block instance
909  * @sb: super_block
910  * @data: mount options
911  * @silent: silent mode flag
912  *
913  * This function is called exclusively by nilfs->ns_mount_mutex.
914  * So, the recovery process is protected from other simultaneous mounts.
915  */
916 static int
917 nilfs_fill_super(struct super_block *sb, void *data, int silent)
918 {
919 	struct the_nilfs *nilfs;
920 	struct nilfs_sb_info *sbi;
921 	struct nilfs_root *fsroot;
922 	struct backing_dev_info *bdi;
923 	__u64 cno;
924 	int err;
925 
926 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
927 	if (!sbi)
928 		return -ENOMEM;
929 
930 	sb->s_fs_info = sbi;
931 	sbi->s_super = sb;
932 
933 	nilfs = alloc_nilfs(sb->s_bdev);
934 	if (!nilfs) {
935 		err = -ENOMEM;
936 		goto failed_sbi;
937 	}
938 	sbi->s_nilfs = nilfs;
939 
940 	err = init_nilfs(nilfs, sbi, (char *)data);
941 	if (err)
942 		goto failed_nilfs;
943 
944 	spin_lock_init(&sbi->s_inode_lock);
945 	INIT_LIST_HEAD(&sbi->s_dirty_files);
946 
947 	/*
948 	 * Following initialization is overlapped because
949 	 * nilfs_sb_info structure has been cleared at the beginning.
950 	 * But we reserve them to keep our interest and make ready
951 	 * for the future change.
952 	 */
953 	get_random_bytes(&sbi->s_next_generation,
954 			 sizeof(sbi->s_next_generation));
955 	spin_lock_init(&sbi->s_next_gen_lock);
956 
957 	sb->s_op = &nilfs_sops;
958 	sb->s_export_op = &nilfs_export_ops;
959 	sb->s_root = NULL;
960 	sb->s_time_gran = 1;
961 
962 	bdi = sb->s_bdev->bd_inode->i_mapping->backing_dev_info;
963 	sb->s_bdi = bdi ? : &default_backing_dev_info;
964 
965 	err = load_nilfs(nilfs, sbi);
966 	if (err)
967 		goto failed_nilfs;
968 
969 	cno = nilfs_last_cno(nilfs);
970 	err = nilfs_attach_checkpoint(sbi, cno, true, &fsroot);
971 	if (err) {
972 		printk(KERN_ERR "NILFS: error loading last checkpoint "
973 		       "(checkpoint number=%llu).\n", (unsigned long long)cno);
974 		goto failed_unload;
975 	}
976 
977 	if (!(sb->s_flags & MS_RDONLY)) {
978 		err = nilfs_attach_segment_constructor(sbi, fsroot);
979 		if (err)
980 			goto failed_checkpoint;
981 	}
982 
983 	err = nilfs_get_root_dentry(sb, fsroot, &sb->s_root);
984 	if (err)
985 		goto failed_segctor;
986 
987 	nilfs_put_root(fsroot);
988 
989 	if (!(sb->s_flags & MS_RDONLY)) {
990 		down_write(&nilfs->ns_sem);
991 		nilfs_setup_super(sbi, true);
992 		up_write(&nilfs->ns_sem);
993 	}
994 
995 	return 0;
996 
997  failed_segctor:
998 	nilfs_detach_segment_constructor(sbi);
999 
1000  failed_checkpoint:
1001 	nilfs_put_root(fsroot);
1002 
1003  failed_unload:
1004 	iput(nilfs->ns_sufile);
1005 	iput(nilfs->ns_cpfile);
1006 	iput(nilfs->ns_dat);
1007 
1008  failed_nilfs:
1009 	destroy_nilfs(nilfs);
1010 
1011  failed_sbi:
1012 	sb->s_fs_info = NULL;
1013 	kfree(sbi);
1014 	return err;
1015 }
1016 
1017 static int nilfs_remount(struct super_block *sb, int *flags, char *data)
1018 {
1019 	struct nilfs_sb_info *sbi = NILFS_SB(sb);
1020 	struct the_nilfs *nilfs = sbi->s_nilfs;
1021 	unsigned long old_sb_flags;
1022 	unsigned long old_mount_opt;
1023 	int err;
1024 
1025 	old_sb_flags = sb->s_flags;
1026 	old_mount_opt = sbi->s_mount_opt;
1027 
1028 	if (!parse_options(data, sb, 1)) {
1029 		err = -EINVAL;
1030 		goto restore_opts;
1031 	}
1032 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL);
1033 
1034 	err = -EINVAL;
1035 
1036 	if (!nilfs_valid_fs(nilfs)) {
1037 		printk(KERN_WARNING "NILFS (device %s): couldn't "
1038 		       "remount because the filesystem is in an "
1039 		       "incomplete recovery state.\n", sb->s_id);
1040 		goto restore_opts;
1041 	}
1042 
1043 	if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1044 		goto out;
1045 	if (*flags & MS_RDONLY) {
1046 		/* Shutting down the segment constructor */
1047 		nilfs_detach_segment_constructor(sbi);
1048 		sb->s_flags |= MS_RDONLY;
1049 
1050 		/*
1051 		 * Remounting a valid RW partition RDONLY, so set
1052 		 * the RDONLY flag and then mark the partition as valid again.
1053 		 */
1054 		down_write(&nilfs->ns_sem);
1055 		nilfs_cleanup_super(sbi);
1056 		up_write(&nilfs->ns_sem);
1057 	} else {
1058 		__u64 features;
1059 		struct nilfs_root *root;
1060 
1061 		/*
1062 		 * Mounting a RDONLY partition read-write, so reread and
1063 		 * store the current valid flag.  (It may have been changed
1064 		 * by fsck since we originally mounted the partition.)
1065 		 */
1066 		down_read(&nilfs->ns_sem);
1067 		features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
1068 			~NILFS_FEATURE_COMPAT_RO_SUPP;
1069 		up_read(&nilfs->ns_sem);
1070 		if (features) {
1071 			printk(KERN_WARNING "NILFS (device %s): couldn't "
1072 			       "remount RDWR because of unsupported optional "
1073 			       "features (%llx)\n",
1074 			       sb->s_id, (unsigned long long)features);
1075 			err = -EROFS;
1076 			goto restore_opts;
1077 		}
1078 
1079 		sb->s_flags &= ~MS_RDONLY;
1080 
1081 		root = NILFS_I(sb->s_root->d_inode)->i_root;
1082 		err = nilfs_attach_segment_constructor(sbi, root);
1083 		if (err)
1084 			goto restore_opts;
1085 
1086 		down_write(&nilfs->ns_sem);
1087 		nilfs_setup_super(sbi, true);
1088 		up_write(&nilfs->ns_sem);
1089 	}
1090  out:
1091 	return 0;
1092 
1093  restore_opts:
1094 	sb->s_flags = old_sb_flags;
1095 	sbi->s_mount_opt = old_mount_opt;
1096 	return err;
1097 }
1098 
1099 struct nilfs_super_data {
1100 	struct block_device *bdev;
1101 	struct nilfs_sb_info *sbi;
1102 	__u64 cno;
1103 	int flags;
1104 };
1105 
1106 /**
1107  * nilfs_identify - pre-read mount options needed to identify mount instance
1108  * @data: mount options
1109  * @sd: nilfs_super_data
1110  */
1111 static int nilfs_identify(char *data, struct nilfs_super_data *sd)
1112 {
1113 	char *p, *options = data;
1114 	substring_t args[MAX_OPT_ARGS];
1115 	int token;
1116 	int ret = 0;
1117 
1118 	do {
1119 		p = strsep(&options, ",");
1120 		if (p != NULL && *p) {
1121 			token = match_token(p, tokens, args);
1122 			if (token == Opt_snapshot) {
1123 				if (!(sd->flags & MS_RDONLY)) {
1124 					ret++;
1125 				} else {
1126 					sd->cno = simple_strtoull(args[0].from,
1127 								  NULL, 0);
1128 					/*
1129 					 * No need to see the end pointer;
1130 					 * match_token() has done syntax
1131 					 * checking.
1132 					 */
1133 					if (sd->cno == 0)
1134 						ret++;
1135 				}
1136 			}
1137 			if (ret)
1138 				printk(KERN_ERR
1139 				       "NILFS: invalid mount option: %s\n", p);
1140 		}
1141 		if (!options)
1142 			break;
1143 		BUG_ON(options == data);
1144 		*(options - 1) = ',';
1145 	} while (!ret);
1146 	return ret;
1147 }
1148 
1149 static int nilfs_set_bdev_super(struct super_block *s, void *data)
1150 {
1151 	s->s_bdev = data;
1152 	s->s_dev = s->s_bdev->bd_dev;
1153 	return 0;
1154 }
1155 
1156 static int nilfs_test_bdev_super(struct super_block *s, void *data)
1157 {
1158 	return (void *)s->s_bdev == data;
1159 }
1160 
1161 static struct dentry *
1162 nilfs_mount(struct file_system_type *fs_type, int flags,
1163 	     const char *dev_name, void *data)
1164 {
1165 	struct nilfs_super_data sd;
1166 	struct super_block *s;
1167 	fmode_t mode = FMODE_READ | FMODE_EXCL;
1168 	struct dentry *root_dentry;
1169 	int err, s_new = false;
1170 
1171 	if (!(flags & MS_RDONLY))
1172 		mode |= FMODE_WRITE;
1173 
1174 	sd.bdev = blkdev_get_by_path(dev_name, mode, fs_type);
1175 	if (IS_ERR(sd.bdev))
1176 		return ERR_CAST(sd.bdev);
1177 
1178 	sd.cno = 0;
1179 	sd.flags = flags;
1180 	if (nilfs_identify((char *)data, &sd)) {
1181 		err = -EINVAL;
1182 		goto failed;
1183 	}
1184 
1185 	/*
1186 	 * once the super is inserted into the list by sget, s_umount
1187 	 * will protect the lockfs code from trying to start a snapshot
1188 	 * while we are mounting
1189 	 */
1190 	mutex_lock(&sd.bdev->bd_fsfreeze_mutex);
1191 	if (sd.bdev->bd_fsfreeze_count > 0) {
1192 		mutex_unlock(&sd.bdev->bd_fsfreeze_mutex);
1193 		err = -EBUSY;
1194 		goto failed;
1195 	}
1196 	s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, sd.bdev);
1197 	mutex_unlock(&sd.bdev->bd_fsfreeze_mutex);
1198 	if (IS_ERR(s)) {
1199 		err = PTR_ERR(s);
1200 		goto failed;
1201 	}
1202 
1203 	if (!s->s_root) {
1204 		char b[BDEVNAME_SIZE];
1205 
1206 		s_new = true;
1207 
1208 		/* New superblock instance created */
1209 		s->s_flags = flags;
1210 		s->s_mode = mode;
1211 		strlcpy(s->s_id, bdevname(sd.bdev, b), sizeof(s->s_id));
1212 		sb_set_blocksize(s, block_size(sd.bdev));
1213 
1214 		err = nilfs_fill_super(s, data, flags & MS_SILENT ? 1 : 0);
1215 		if (err)
1216 			goto failed_super;
1217 
1218 		s->s_flags |= MS_ACTIVE;
1219 	} else if (!sd.cno) {
1220 		int busy = false;
1221 
1222 		if (nilfs_tree_was_touched(s->s_root)) {
1223 			busy = nilfs_try_to_shrink_tree(s->s_root);
1224 			if (busy && (flags ^ s->s_flags) & MS_RDONLY) {
1225 				printk(KERN_ERR "NILFS: the device already "
1226 				       "has a %s mount.\n",
1227 				       (s->s_flags & MS_RDONLY) ?
1228 				       "read-only" : "read/write");
1229 				err = -EBUSY;
1230 				goto failed_super;
1231 			}
1232 		}
1233 		if (!busy) {
1234 			/*
1235 			 * Try remount to setup mount states if the current
1236 			 * tree is not mounted and only snapshots use this sb.
1237 			 */
1238 			err = nilfs_remount(s, &flags, data);
1239 			if (err)
1240 				goto failed_super;
1241 		}
1242 	}
1243 
1244 	if (sd.cno) {
1245 		err = nilfs_attach_snapshot(s, sd.cno, &root_dentry);
1246 		if (err)
1247 			goto failed_super;
1248 	} else {
1249 		root_dentry = dget(s->s_root);
1250 	}
1251 
1252 	if (!s_new)
1253 		blkdev_put(sd.bdev, mode);
1254 
1255 	return root_dentry;
1256 
1257  failed_super:
1258 	deactivate_locked_super(s);
1259 
1260  failed:
1261 	if (!s_new)
1262 		blkdev_put(sd.bdev, mode);
1263 	return ERR_PTR(err);
1264 }
1265 
1266 struct file_system_type nilfs_fs_type = {
1267 	.owner    = THIS_MODULE,
1268 	.name     = "nilfs2",
1269 	.mount    = nilfs_mount,
1270 	.kill_sb  = kill_block_super,
1271 	.fs_flags = FS_REQUIRES_DEV,
1272 };
1273 
1274 static void nilfs_inode_init_once(void *obj)
1275 {
1276 	struct nilfs_inode_info *ii = obj;
1277 
1278 	INIT_LIST_HEAD(&ii->i_dirty);
1279 #ifdef CONFIG_NILFS_XATTR
1280 	init_rwsem(&ii->xattr_sem);
1281 #endif
1282 	address_space_init_once(&ii->i_btnode_cache);
1283 	ii->i_bmap = &ii->i_bmap_data;
1284 	inode_init_once(&ii->vfs_inode);
1285 }
1286 
1287 static void nilfs_segbuf_init_once(void *obj)
1288 {
1289 	memset(obj, 0, sizeof(struct nilfs_segment_buffer));
1290 }
1291 
1292 static void nilfs_destroy_cachep(void)
1293 {
1294 	if (nilfs_inode_cachep)
1295 		kmem_cache_destroy(nilfs_inode_cachep);
1296 	if (nilfs_transaction_cachep)
1297 		kmem_cache_destroy(nilfs_transaction_cachep);
1298 	if (nilfs_segbuf_cachep)
1299 		kmem_cache_destroy(nilfs_segbuf_cachep);
1300 	if (nilfs_btree_path_cache)
1301 		kmem_cache_destroy(nilfs_btree_path_cache);
1302 }
1303 
1304 static int __init nilfs_init_cachep(void)
1305 {
1306 	nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache",
1307 			sizeof(struct nilfs_inode_info), 0,
1308 			SLAB_RECLAIM_ACCOUNT, nilfs_inode_init_once);
1309 	if (!nilfs_inode_cachep)
1310 		goto fail;
1311 
1312 	nilfs_transaction_cachep = kmem_cache_create("nilfs2_transaction_cache",
1313 			sizeof(struct nilfs_transaction_info), 0,
1314 			SLAB_RECLAIM_ACCOUNT, NULL);
1315 	if (!nilfs_transaction_cachep)
1316 		goto fail;
1317 
1318 	nilfs_segbuf_cachep = kmem_cache_create("nilfs2_segbuf_cache",
1319 			sizeof(struct nilfs_segment_buffer), 0,
1320 			SLAB_RECLAIM_ACCOUNT, nilfs_segbuf_init_once);
1321 	if (!nilfs_segbuf_cachep)
1322 		goto fail;
1323 
1324 	nilfs_btree_path_cache = kmem_cache_create("nilfs2_btree_path_cache",
1325 			sizeof(struct nilfs_btree_path) * NILFS_BTREE_LEVEL_MAX,
1326 			0, 0, NULL);
1327 	if (!nilfs_btree_path_cache)
1328 		goto fail;
1329 
1330 	return 0;
1331 
1332 fail:
1333 	nilfs_destroy_cachep();
1334 	return -ENOMEM;
1335 }
1336 
1337 static int __init init_nilfs_fs(void)
1338 {
1339 	int err;
1340 
1341 	err = nilfs_init_cachep();
1342 	if (err)
1343 		goto fail;
1344 
1345 	err = register_filesystem(&nilfs_fs_type);
1346 	if (err)
1347 		goto free_cachep;
1348 
1349 	printk(KERN_INFO "NILFS version 2 loaded\n");
1350 	return 0;
1351 
1352 free_cachep:
1353 	nilfs_destroy_cachep();
1354 fail:
1355 	return err;
1356 }
1357 
1358 static void __exit exit_nilfs_fs(void)
1359 {
1360 	nilfs_destroy_cachep();
1361 	unregister_filesystem(&nilfs_fs_type);
1362 }
1363 
1364 module_init(init_nilfs_fs)
1365 module_exit(exit_nilfs_fs)
1366