xref: /linux/fs/f2fs/super.c (revision 6e6d9ba0d1ea224a877826fc1cc0f42878b60384)
1 /*
2  * fs/f2fs/super.c
3  *
4  * Copyright (c) 2012 Samsung Electronics Co., Ltd.
5  *             http://www.samsung.com/
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 #include <linux/module.h>
12 #include <linux/init.h>
13 #include <linux/fs.h>
14 #include <linux/statfs.h>
15 #include <linux/proc_fs.h>
16 #include <linux/buffer_head.h>
17 #include <linux/backing-dev.h>
18 #include <linux/kthread.h>
19 #include <linux/parser.h>
20 #include <linux/mount.h>
21 #include <linux/seq_file.h>
22 #include <linux/random.h>
23 #include <linux/exportfs.h>
24 #include <linux/f2fs_fs.h>
25 
26 #include "f2fs.h"
27 #include "node.h"
28 #include "xattr.h"
29 
30 static struct kmem_cache *f2fs_inode_cachep;
31 
32 enum {
33 	Opt_gc_background_off,
34 	Opt_disable_roll_forward,
35 	Opt_discard,
36 	Opt_noheap,
37 	Opt_nouser_xattr,
38 	Opt_noacl,
39 	Opt_active_logs,
40 	Opt_disable_ext_identify,
41 	Opt_err,
42 };
43 
44 static match_table_t f2fs_tokens = {
45 	{Opt_gc_background_off, "background_gc_off"},
46 	{Opt_disable_roll_forward, "disable_roll_forward"},
47 	{Opt_discard, "discard"},
48 	{Opt_noheap, "no_heap"},
49 	{Opt_nouser_xattr, "nouser_xattr"},
50 	{Opt_noacl, "noacl"},
51 	{Opt_active_logs, "active_logs=%u"},
52 	{Opt_disable_ext_identify, "disable_ext_identify"},
53 	{Opt_err, NULL},
54 };
55 
56 void f2fs_msg(struct super_block *sb, const char *level, const char *fmt, ...)
57 {
58 	struct va_format vaf;
59 	va_list args;
60 
61 	va_start(args, fmt);
62 	vaf.fmt = fmt;
63 	vaf.va = &args;
64 	printk("%sF2FS-fs (%s): %pV\n", level, sb->s_id, &vaf);
65 	va_end(args);
66 }
67 
68 static void init_once(void *foo)
69 {
70 	struct f2fs_inode_info *fi = (struct f2fs_inode_info *) foo;
71 
72 	inode_init_once(&fi->vfs_inode);
73 }
74 
75 static struct inode *f2fs_alloc_inode(struct super_block *sb)
76 {
77 	struct f2fs_inode_info *fi;
78 
79 	fi = kmem_cache_alloc(f2fs_inode_cachep, GFP_NOFS | __GFP_ZERO);
80 	if (!fi)
81 		return NULL;
82 
83 	init_once((void *) fi);
84 
85 	/* Initilize f2fs-specific inode info */
86 	fi->vfs_inode.i_version = 1;
87 	atomic_set(&fi->dirty_dents, 0);
88 	fi->i_current_depth = 1;
89 	fi->i_advise = 0;
90 	rwlock_init(&fi->ext.ext_lock);
91 
92 	set_inode_flag(fi, FI_NEW_INODE);
93 
94 	return &fi->vfs_inode;
95 }
96 
97 static void f2fs_i_callback(struct rcu_head *head)
98 {
99 	struct inode *inode = container_of(head, struct inode, i_rcu);
100 	kmem_cache_free(f2fs_inode_cachep, F2FS_I(inode));
101 }
102 
103 static void f2fs_destroy_inode(struct inode *inode)
104 {
105 	call_rcu(&inode->i_rcu, f2fs_i_callback);
106 }
107 
108 static void f2fs_put_super(struct super_block *sb)
109 {
110 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
111 
112 	f2fs_destroy_stats(sbi);
113 	stop_gc_thread(sbi);
114 
115 	write_checkpoint(sbi, true);
116 
117 	iput(sbi->node_inode);
118 	iput(sbi->meta_inode);
119 
120 	/* destroy f2fs internal modules */
121 	destroy_node_manager(sbi);
122 	destroy_segment_manager(sbi);
123 
124 	kfree(sbi->ckpt);
125 
126 	sb->s_fs_info = NULL;
127 	brelse(sbi->raw_super_buf);
128 	kfree(sbi);
129 }
130 
131 int f2fs_sync_fs(struct super_block *sb, int sync)
132 {
133 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
134 
135 	if (!sbi->s_dirty && !get_pages(sbi, F2FS_DIRTY_NODES))
136 		return 0;
137 
138 	if (sync)
139 		write_checkpoint(sbi, false);
140 	else
141 		f2fs_balance_fs(sbi);
142 
143 	return 0;
144 }
145 
146 static int f2fs_freeze(struct super_block *sb)
147 {
148 	int err;
149 
150 	if (sb->s_flags & MS_RDONLY)
151 		return 0;
152 
153 	err = f2fs_sync_fs(sb, 1);
154 	return err;
155 }
156 
157 static int f2fs_unfreeze(struct super_block *sb)
158 {
159 	return 0;
160 }
161 
162 static int f2fs_statfs(struct dentry *dentry, struct kstatfs *buf)
163 {
164 	struct super_block *sb = dentry->d_sb;
165 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
166 	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
167 	block_t total_count, user_block_count, start_count, ovp_count;
168 
169 	total_count = le64_to_cpu(sbi->raw_super->block_count);
170 	user_block_count = sbi->user_block_count;
171 	start_count = le32_to_cpu(sbi->raw_super->segment0_blkaddr);
172 	ovp_count = SM_I(sbi)->ovp_segments << sbi->log_blocks_per_seg;
173 	buf->f_type = F2FS_SUPER_MAGIC;
174 	buf->f_bsize = sbi->blocksize;
175 
176 	buf->f_blocks = total_count - start_count;
177 	buf->f_bfree = buf->f_blocks - valid_user_blocks(sbi) - ovp_count;
178 	buf->f_bavail = user_block_count - valid_user_blocks(sbi);
179 
180 	buf->f_files = sbi->total_node_count;
181 	buf->f_ffree = sbi->total_node_count - valid_inode_count(sbi);
182 
183 	buf->f_namelen = F2FS_MAX_NAME_LEN;
184 	buf->f_fsid.val[0] = (u32)id;
185 	buf->f_fsid.val[1] = (u32)(id >> 32);
186 
187 	return 0;
188 }
189 
190 static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
191 {
192 	struct f2fs_sb_info *sbi = F2FS_SB(root->d_sb);
193 
194 	if (test_opt(sbi, BG_GC))
195 		seq_puts(seq, ",background_gc_on");
196 	else
197 		seq_puts(seq, ",background_gc_off");
198 	if (test_opt(sbi, DISABLE_ROLL_FORWARD))
199 		seq_puts(seq, ",disable_roll_forward");
200 	if (test_opt(sbi, DISCARD))
201 		seq_puts(seq, ",discard");
202 	if (test_opt(sbi, NOHEAP))
203 		seq_puts(seq, ",no_heap_alloc");
204 #ifdef CONFIG_F2FS_FS_XATTR
205 	if (test_opt(sbi, XATTR_USER))
206 		seq_puts(seq, ",user_xattr");
207 	else
208 		seq_puts(seq, ",nouser_xattr");
209 #endif
210 #ifdef CONFIG_F2FS_FS_POSIX_ACL
211 	if (test_opt(sbi, POSIX_ACL))
212 		seq_puts(seq, ",acl");
213 	else
214 		seq_puts(seq, ",noacl");
215 #endif
216 	if (test_opt(sbi, DISABLE_EXT_IDENTIFY))
217 		seq_puts(seq, ",disable_ext_identify");
218 
219 	seq_printf(seq, ",active_logs=%u", sbi->active_logs);
220 
221 	return 0;
222 }
223 
224 static struct super_operations f2fs_sops = {
225 	.alloc_inode	= f2fs_alloc_inode,
226 	.destroy_inode	= f2fs_destroy_inode,
227 	.write_inode	= f2fs_write_inode,
228 	.show_options	= f2fs_show_options,
229 	.evict_inode	= f2fs_evict_inode,
230 	.put_super	= f2fs_put_super,
231 	.sync_fs	= f2fs_sync_fs,
232 	.freeze_fs	= f2fs_freeze,
233 	.unfreeze_fs	= f2fs_unfreeze,
234 	.statfs		= f2fs_statfs,
235 };
236 
237 static struct inode *f2fs_nfs_get_inode(struct super_block *sb,
238 		u64 ino, u32 generation)
239 {
240 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
241 	struct inode *inode;
242 
243 	if (ino < F2FS_ROOT_INO(sbi))
244 		return ERR_PTR(-ESTALE);
245 
246 	/*
247 	 * f2fs_iget isn't quite right if the inode is currently unallocated!
248 	 * However f2fs_iget currently does appropriate checks to handle stale
249 	 * inodes so everything is OK.
250 	 */
251 	inode = f2fs_iget(sb, ino);
252 	if (IS_ERR(inode))
253 		return ERR_CAST(inode);
254 	if (generation && inode->i_generation != generation) {
255 		/* we didn't find the right inode.. */
256 		iput(inode);
257 		return ERR_PTR(-ESTALE);
258 	}
259 	return inode;
260 }
261 
262 static struct dentry *f2fs_fh_to_dentry(struct super_block *sb, struct fid *fid,
263 		int fh_len, int fh_type)
264 {
265 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
266 				    f2fs_nfs_get_inode);
267 }
268 
269 static struct dentry *f2fs_fh_to_parent(struct super_block *sb, struct fid *fid,
270 		int fh_len, int fh_type)
271 {
272 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
273 				    f2fs_nfs_get_inode);
274 }
275 
276 static const struct export_operations f2fs_export_ops = {
277 	.fh_to_dentry = f2fs_fh_to_dentry,
278 	.fh_to_parent = f2fs_fh_to_parent,
279 	.get_parent = f2fs_get_parent,
280 };
281 
282 static int parse_options(struct super_block *sb, struct f2fs_sb_info *sbi,
283 				char *options)
284 {
285 	substring_t args[MAX_OPT_ARGS];
286 	char *p;
287 	int arg = 0;
288 
289 	if (!options)
290 		return 0;
291 
292 	while ((p = strsep(&options, ",")) != NULL) {
293 		int token;
294 		if (!*p)
295 			continue;
296 		/*
297 		 * Initialize args struct so we know whether arg was
298 		 * found; some options take optional arguments.
299 		 */
300 		args[0].to = args[0].from = NULL;
301 		token = match_token(p, f2fs_tokens, args);
302 
303 		switch (token) {
304 		case Opt_gc_background_off:
305 			clear_opt(sbi, BG_GC);
306 			break;
307 		case Opt_disable_roll_forward:
308 			set_opt(sbi, DISABLE_ROLL_FORWARD);
309 			break;
310 		case Opt_discard:
311 			set_opt(sbi, DISCARD);
312 			break;
313 		case Opt_noheap:
314 			set_opt(sbi, NOHEAP);
315 			break;
316 #ifdef CONFIG_F2FS_FS_XATTR
317 		case Opt_nouser_xattr:
318 			clear_opt(sbi, XATTR_USER);
319 			break;
320 #else
321 		case Opt_nouser_xattr:
322 			f2fs_msg(sb, KERN_INFO,
323 				"nouser_xattr options not supported");
324 			break;
325 #endif
326 #ifdef CONFIG_F2FS_FS_POSIX_ACL
327 		case Opt_noacl:
328 			clear_opt(sbi, POSIX_ACL);
329 			break;
330 #else
331 		case Opt_noacl:
332 			f2fs_msg(sb, KERN_INFO, "noacl options not supported");
333 			break;
334 #endif
335 		case Opt_active_logs:
336 			if (args->from && match_int(args, &arg))
337 				return -EINVAL;
338 			if (arg != 2 && arg != 4 && arg != NR_CURSEG_TYPE)
339 				return -EINVAL;
340 			sbi->active_logs = arg;
341 			break;
342 		case Opt_disable_ext_identify:
343 			set_opt(sbi, DISABLE_EXT_IDENTIFY);
344 			break;
345 		default:
346 			f2fs_msg(sb, KERN_ERR,
347 				"Unrecognized mount option \"%s\" or missing value",
348 				p);
349 			return -EINVAL;
350 		}
351 	}
352 	return 0;
353 }
354 
355 static loff_t max_file_size(unsigned bits)
356 {
357 	loff_t result = ADDRS_PER_INODE;
358 	loff_t leaf_count = ADDRS_PER_BLOCK;
359 
360 	/* two direct node blocks */
361 	result += (leaf_count * 2);
362 
363 	/* two indirect node blocks */
364 	leaf_count *= NIDS_PER_BLOCK;
365 	result += (leaf_count * 2);
366 
367 	/* one double indirect node block */
368 	leaf_count *= NIDS_PER_BLOCK;
369 	result += leaf_count;
370 
371 	result <<= bits;
372 	return result;
373 }
374 
375 static int sanity_check_raw_super(struct super_block *sb,
376 			struct f2fs_super_block *raw_super)
377 {
378 	unsigned int blocksize;
379 
380 	if (F2FS_SUPER_MAGIC != le32_to_cpu(raw_super->magic)) {
381 		f2fs_msg(sb, KERN_INFO,
382 			"Magic Mismatch, valid(0x%x) - read(0x%x)",
383 			F2FS_SUPER_MAGIC, le32_to_cpu(raw_super->magic));
384 		return 1;
385 	}
386 
387 	/* Currently, support only 4KB page cache size */
388 	if (F2FS_BLKSIZE != PAGE_CACHE_SIZE) {
389 		f2fs_msg(sb, KERN_INFO,
390 			"Invalid page_cache_size (%lu), supports only 4KB\n",
391 			PAGE_CACHE_SIZE);
392 		return 1;
393 	}
394 
395 	/* Currently, support only 4KB block size */
396 	blocksize = 1 << le32_to_cpu(raw_super->log_blocksize);
397 	if (blocksize != F2FS_BLKSIZE) {
398 		f2fs_msg(sb, KERN_INFO,
399 			"Invalid blocksize (%u), supports only 4KB\n",
400 			blocksize);
401 		return 1;
402 	}
403 
404 	if (le32_to_cpu(raw_super->log_sectorsize) !=
405 					F2FS_LOG_SECTOR_SIZE) {
406 		f2fs_msg(sb, KERN_INFO, "Invalid log sectorsize");
407 		return 1;
408 	}
409 	if (le32_to_cpu(raw_super->log_sectors_per_block) !=
410 					F2FS_LOG_SECTORS_PER_BLOCK) {
411 		f2fs_msg(sb, KERN_INFO, "Invalid log sectors per block");
412 		return 1;
413 	}
414 	return 0;
415 }
416 
417 static int sanity_check_ckpt(struct f2fs_sb_info *sbi)
418 {
419 	unsigned int total, fsmeta;
420 	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
421 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
422 
423 	total = le32_to_cpu(raw_super->segment_count);
424 	fsmeta = le32_to_cpu(raw_super->segment_count_ckpt);
425 	fsmeta += le32_to_cpu(raw_super->segment_count_sit);
426 	fsmeta += le32_to_cpu(raw_super->segment_count_nat);
427 	fsmeta += le32_to_cpu(ckpt->rsvd_segment_count);
428 	fsmeta += le32_to_cpu(raw_super->segment_count_ssa);
429 
430 	if (fsmeta >= total)
431 		return 1;
432 
433 	if (is_set_ckpt_flags(ckpt, CP_ERROR_FLAG)) {
434 		f2fs_msg(sbi->sb, KERN_ERR, "A bug case: need to run fsck");
435 		return 1;
436 	}
437 	return 0;
438 }
439 
440 static void init_sb_info(struct f2fs_sb_info *sbi)
441 {
442 	struct f2fs_super_block *raw_super = sbi->raw_super;
443 	int i;
444 
445 	sbi->log_sectors_per_block =
446 		le32_to_cpu(raw_super->log_sectors_per_block);
447 	sbi->log_blocksize = le32_to_cpu(raw_super->log_blocksize);
448 	sbi->blocksize = 1 << sbi->log_blocksize;
449 	sbi->log_blocks_per_seg = le32_to_cpu(raw_super->log_blocks_per_seg);
450 	sbi->blocks_per_seg = 1 << sbi->log_blocks_per_seg;
451 	sbi->segs_per_sec = le32_to_cpu(raw_super->segs_per_sec);
452 	sbi->secs_per_zone = le32_to_cpu(raw_super->secs_per_zone);
453 	sbi->total_sections = le32_to_cpu(raw_super->section_count);
454 	sbi->total_node_count =
455 		(le32_to_cpu(raw_super->segment_count_nat) / 2)
456 			* sbi->blocks_per_seg * NAT_ENTRY_PER_BLOCK;
457 	sbi->root_ino_num = le32_to_cpu(raw_super->root_ino);
458 	sbi->node_ino_num = le32_to_cpu(raw_super->node_ino);
459 	sbi->meta_ino_num = le32_to_cpu(raw_super->meta_ino);
460 
461 	for (i = 0; i < NR_COUNT_TYPE; i++)
462 		atomic_set(&sbi->nr_pages[i], 0);
463 }
464 
465 static int validate_superblock(struct super_block *sb,
466 		struct f2fs_super_block **raw_super,
467 		struct buffer_head **raw_super_buf, sector_t block)
468 {
469 	const char *super = (block == 0 ? "first" : "second");
470 
471 	/* read f2fs raw super block */
472 	*raw_super_buf = sb_bread(sb, block);
473 	if (!*raw_super_buf) {
474 		f2fs_msg(sb, KERN_ERR, "unable to read %s superblock",
475 				super);
476 		return 1;
477 	}
478 
479 	*raw_super = (struct f2fs_super_block *)
480 		((char *)(*raw_super_buf)->b_data + F2FS_SUPER_OFFSET);
481 
482 	/* sanity checking of raw super */
483 	if (!sanity_check_raw_super(sb, *raw_super))
484 		return 0;
485 
486 	f2fs_msg(sb, KERN_ERR, "Can't find a valid F2FS filesystem "
487 				"in %s superblock", super);
488 	return 1;
489 }
490 
491 static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
492 {
493 	struct f2fs_sb_info *sbi;
494 	struct f2fs_super_block *raw_super;
495 	struct buffer_head *raw_super_buf;
496 	struct inode *root;
497 	long err = -EINVAL;
498 	int i;
499 
500 	/* allocate memory for f2fs-specific super block info */
501 	sbi = kzalloc(sizeof(struct f2fs_sb_info), GFP_KERNEL);
502 	if (!sbi)
503 		return -ENOMEM;
504 
505 	/* set a block size */
506 	if (!sb_set_blocksize(sb, F2FS_BLKSIZE)) {
507 		f2fs_msg(sb, KERN_ERR, "unable to set blocksize");
508 		goto free_sbi;
509 	}
510 
511 	if (validate_superblock(sb, &raw_super, &raw_super_buf, 0)) {
512 		brelse(raw_super_buf);
513 		if (validate_superblock(sb, &raw_super, &raw_super_buf, 1))
514 			goto free_sb_buf;
515 	}
516 	/* init some FS parameters */
517 	sbi->active_logs = NR_CURSEG_TYPE;
518 
519 	set_opt(sbi, BG_GC);
520 
521 #ifdef CONFIG_F2FS_FS_XATTR
522 	set_opt(sbi, XATTR_USER);
523 #endif
524 #ifdef CONFIG_F2FS_FS_POSIX_ACL
525 	set_opt(sbi, POSIX_ACL);
526 #endif
527 	/* parse mount options */
528 	if (parse_options(sb, sbi, (char *)data))
529 		goto free_sb_buf;
530 
531 	sb->s_maxbytes = max_file_size(le32_to_cpu(raw_super->log_blocksize));
532 	sb->s_max_links = F2FS_LINK_MAX;
533 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
534 
535 	sb->s_op = &f2fs_sops;
536 	sb->s_xattr = f2fs_xattr_handlers;
537 	sb->s_export_op = &f2fs_export_ops;
538 	sb->s_magic = F2FS_SUPER_MAGIC;
539 	sb->s_fs_info = sbi;
540 	sb->s_time_gran = 1;
541 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
542 		(test_opt(sbi, POSIX_ACL) ? MS_POSIXACL : 0);
543 	memcpy(sb->s_uuid, raw_super->uuid, sizeof(raw_super->uuid));
544 
545 	/* init f2fs-specific super block info */
546 	sbi->sb = sb;
547 	sbi->raw_super = raw_super;
548 	sbi->raw_super_buf = raw_super_buf;
549 	mutex_init(&sbi->gc_mutex);
550 	mutex_init(&sbi->write_inode);
551 	mutex_init(&sbi->writepages);
552 	mutex_init(&sbi->cp_mutex);
553 	for (i = 0; i < NR_LOCK_TYPE; i++)
554 		mutex_init(&sbi->fs_lock[i]);
555 	sbi->por_doing = 0;
556 	spin_lock_init(&sbi->stat_lock);
557 	init_rwsem(&sbi->bio_sem);
558 	init_sb_info(sbi);
559 
560 	/* get an inode for meta space */
561 	sbi->meta_inode = f2fs_iget(sb, F2FS_META_INO(sbi));
562 	if (IS_ERR(sbi->meta_inode)) {
563 		f2fs_msg(sb, KERN_ERR, "Failed to read F2FS meta data inode");
564 		err = PTR_ERR(sbi->meta_inode);
565 		goto free_sb_buf;
566 	}
567 
568 	err = get_valid_checkpoint(sbi);
569 	if (err) {
570 		f2fs_msg(sb, KERN_ERR, "Failed to get valid F2FS checkpoint");
571 		goto free_meta_inode;
572 	}
573 
574 	/* sanity checking of checkpoint */
575 	err = -EINVAL;
576 	if (sanity_check_ckpt(sbi)) {
577 		f2fs_msg(sb, KERN_ERR, "Invalid F2FS checkpoint");
578 		goto free_cp;
579 	}
580 
581 	sbi->total_valid_node_count =
582 				le32_to_cpu(sbi->ckpt->valid_node_count);
583 	sbi->total_valid_inode_count =
584 				le32_to_cpu(sbi->ckpt->valid_inode_count);
585 	sbi->user_block_count = le64_to_cpu(sbi->ckpt->user_block_count);
586 	sbi->total_valid_block_count =
587 				le64_to_cpu(sbi->ckpt->valid_block_count);
588 	sbi->last_valid_block_count = sbi->total_valid_block_count;
589 	sbi->alloc_valid_block_count = 0;
590 	INIT_LIST_HEAD(&sbi->dir_inode_list);
591 	spin_lock_init(&sbi->dir_inode_lock);
592 
593 	init_orphan_info(sbi);
594 
595 	/* setup f2fs internal modules */
596 	err = build_segment_manager(sbi);
597 	if (err) {
598 		f2fs_msg(sb, KERN_ERR,
599 			"Failed to initialize F2FS segment manager");
600 		goto free_sm;
601 	}
602 	err = build_node_manager(sbi);
603 	if (err) {
604 		f2fs_msg(sb, KERN_ERR,
605 			"Failed to initialize F2FS node manager");
606 		goto free_nm;
607 	}
608 
609 	build_gc_manager(sbi);
610 
611 	/* get an inode for node space */
612 	sbi->node_inode = f2fs_iget(sb, F2FS_NODE_INO(sbi));
613 	if (IS_ERR(sbi->node_inode)) {
614 		f2fs_msg(sb, KERN_ERR, "Failed to read node inode");
615 		err = PTR_ERR(sbi->node_inode);
616 		goto free_nm;
617 	}
618 
619 	/* if there are nt orphan nodes free them */
620 	err = -EINVAL;
621 	if (recover_orphan_inodes(sbi))
622 		goto free_node_inode;
623 
624 	/* read root inode and dentry */
625 	root = f2fs_iget(sb, F2FS_ROOT_INO(sbi));
626 	if (IS_ERR(root)) {
627 		f2fs_msg(sb, KERN_ERR, "Failed to read root inode");
628 		err = PTR_ERR(root);
629 		goto free_node_inode;
630 	}
631 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size)
632 		goto free_root_inode;
633 
634 	sb->s_root = d_make_root(root); /* allocate root dentry */
635 	if (!sb->s_root) {
636 		err = -ENOMEM;
637 		goto free_root_inode;
638 	}
639 
640 	/* recover fsynced data */
641 	if (!test_opt(sbi, DISABLE_ROLL_FORWARD))
642 		recover_fsync_data(sbi);
643 
644 	/* After POR, we can run background GC thread */
645 	err = start_gc_thread(sbi);
646 	if (err)
647 		goto fail;
648 
649 	err = f2fs_build_stats(sbi);
650 	if (err)
651 		goto fail;
652 
653 	return 0;
654 fail:
655 	stop_gc_thread(sbi);
656 free_root_inode:
657 	dput(sb->s_root);
658 	sb->s_root = NULL;
659 free_node_inode:
660 	iput(sbi->node_inode);
661 free_nm:
662 	destroy_node_manager(sbi);
663 free_sm:
664 	destroy_segment_manager(sbi);
665 free_cp:
666 	kfree(sbi->ckpt);
667 free_meta_inode:
668 	make_bad_inode(sbi->meta_inode);
669 	iput(sbi->meta_inode);
670 free_sb_buf:
671 	brelse(raw_super_buf);
672 free_sbi:
673 	kfree(sbi);
674 	return err;
675 }
676 
677 static struct dentry *f2fs_mount(struct file_system_type *fs_type, int flags,
678 			const char *dev_name, void *data)
679 {
680 	return mount_bdev(fs_type, flags, dev_name, data, f2fs_fill_super);
681 }
682 
683 static struct file_system_type f2fs_fs_type = {
684 	.owner		= THIS_MODULE,
685 	.name		= "f2fs",
686 	.mount		= f2fs_mount,
687 	.kill_sb	= kill_block_super,
688 	.fs_flags	= FS_REQUIRES_DEV,
689 };
690 
691 static int __init init_inodecache(void)
692 {
693 	f2fs_inode_cachep = f2fs_kmem_cache_create("f2fs_inode_cache",
694 			sizeof(struct f2fs_inode_info), NULL);
695 	if (f2fs_inode_cachep == NULL)
696 		return -ENOMEM;
697 	return 0;
698 }
699 
700 static void destroy_inodecache(void)
701 {
702 	/*
703 	 * Make sure all delayed rcu free inodes are flushed before we
704 	 * destroy cache.
705 	 */
706 	rcu_barrier();
707 	kmem_cache_destroy(f2fs_inode_cachep);
708 }
709 
710 static int __init init_f2fs_fs(void)
711 {
712 	int err;
713 
714 	err = init_inodecache();
715 	if (err)
716 		goto fail;
717 	err = create_node_manager_caches();
718 	if (err)
719 		goto fail;
720 	err = create_gc_caches();
721 	if (err)
722 		goto fail;
723 	err = create_checkpoint_caches();
724 	if (err)
725 		goto fail;
726 	err = register_filesystem(&f2fs_fs_type);
727 	if (err)
728 		goto fail;
729 	f2fs_create_root_stats();
730 fail:
731 	return err;
732 }
733 
734 static void __exit exit_f2fs_fs(void)
735 {
736 	f2fs_destroy_root_stats();
737 	unregister_filesystem(&f2fs_fs_type);
738 	destroy_checkpoint_caches();
739 	destroy_gc_caches();
740 	destroy_node_manager_caches();
741 	destroy_inodecache();
742 }
743 
744 module_init(init_f2fs_fs)
745 module_exit(exit_f2fs_fs)
746 
747 MODULE_AUTHOR("Samsung Electronics's Praesto Team");
748 MODULE_DESCRIPTION("Flash Friendly File System");
749 MODULE_LICENSE("GPL");
750