xref: /linux/fs/f2fs/super.c (revision 54f5a57e266318d72f84fda95805099986a7e201)
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/buffer_head.h>
16 #include <linux/backing-dev.h>
17 #include <linux/kthread.h>
18 #include <linux/parser.h>
19 #include <linux/mount.h>
20 #include <linux/seq_file.h>
21 #include <linux/proc_fs.h>
22 #include <linux/random.h>
23 #include <linux/exportfs.h>
24 #include <linux/blkdev.h>
25 #include <linux/f2fs_fs.h>
26 #include <linux/sysfs.h>
27 
28 #include "f2fs.h"
29 #include "node.h"
30 #include "segment.h"
31 #include "xattr.h"
32 #include "gc.h"
33 
34 #define CREATE_TRACE_POINTS
35 #include <trace/events/f2fs.h>
36 
37 static struct proc_dir_entry *f2fs_proc_root;
38 static struct kmem_cache *f2fs_inode_cachep;
39 static struct kset *f2fs_kset;
40 
41 enum {
42 	Opt_gc_background,
43 	Opt_disable_roll_forward,
44 	Opt_discard,
45 	Opt_noheap,
46 	Opt_user_xattr,
47 	Opt_nouser_xattr,
48 	Opt_acl,
49 	Opt_noacl,
50 	Opt_active_logs,
51 	Opt_disable_ext_identify,
52 	Opt_inline_xattr,
53 	Opt_inline_data,
54 	Opt_err,
55 };
56 
57 static match_table_t f2fs_tokens = {
58 	{Opt_gc_background, "background_gc=%s"},
59 	{Opt_disable_roll_forward, "disable_roll_forward"},
60 	{Opt_discard, "discard"},
61 	{Opt_noheap, "no_heap"},
62 	{Opt_user_xattr, "user_xattr"},
63 	{Opt_nouser_xattr, "nouser_xattr"},
64 	{Opt_acl, "acl"},
65 	{Opt_noacl, "noacl"},
66 	{Opt_active_logs, "active_logs=%u"},
67 	{Opt_disable_ext_identify, "disable_ext_identify"},
68 	{Opt_inline_xattr, "inline_xattr"},
69 	{Opt_inline_data, "inline_data"},
70 	{Opt_err, NULL},
71 };
72 
73 /* Sysfs support for f2fs */
74 enum {
75 	GC_THREAD,	/* struct f2fs_gc_thread */
76 	SM_INFO,	/* struct f2fs_sm_info */
77 	F2FS_SBI,	/* struct f2fs_sb_info */
78 };
79 
80 struct f2fs_attr {
81 	struct attribute attr;
82 	ssize_t (*show)(struct f2fs_attr *, struct f2fs_sb_info *, char *);
83 	ssize_t (*store)(struct f2fs_attr *, struct f2fs_sb_info *,
84 			 const char *, size_t);
85 	int struct_type;
86 	int offset;
87 };
88 
89 static unsigned char *__struct_ptr(struct f2fs_sb_info *sbi, int struct_type)
90 {
91 	if (struct_type == GC_THREAD)
92 		return (unsigned char *)sbi->gc_thread;
93 	else if (struct_type == SM_INFO)
94 		return (unsigned char *)SM_I(sbi);
95 	else if (struct_type == F2FS_SBI)
96 		return (unsigned char *)sbi;
97 	return NULL;
98 }
99 
100 static ssize_t f2fs_sbi_show(struct f2fs_attr *a,
101 			struct f2fs_sb_info *sbi, char *buf)
102 {
103 	unsigned char *ptr = NULL;
104 	unsigned int *ui;
105 
106 	ptr = __struct_ptr(sbi, a->struct_type);
107 	if (!ptr)
108 		return -EINVAL;
109 
110 	ui = (unsigned int *)(ptr + a->offset);
111 
112 	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
113 }
114 
115 static ssize_t f2fs_sbi_store(struct f2fs_attr *a,
116 			struct f2fs_sb_info *sbi,
117 			const char *buf, size_t count)
118 {
119 	unsigned char *ptr;
120 	unsigned long t;
121 	unsigned int *ui;
122 	ssize_t ret;
123 
124 	ptr = __struct_ptr(sbi, a->struct_type);
125 	if (!ptr)
126 		return -EINVAL;
127 
128 	ui = (unsigned int *)(ptr + a->offset);
129 
130 	ret = kstrtoul(skip_spaces(buf), 0, &t);
131 	if (ret < 0)
132 		return ret;
133 	*ui = t;
134 	return count;
135 }
136 
137 static ssize_t f2fs_attr_show(struct kobject *kobj,
138 				struct attribute *attr, char *buf)
139 {
140 	struct f2fs_sb_info *sbi = container_of(kobj, struct f2fs_sb_info,
141 								s_kobj);
142 	struct f2fs_attr *a = container_of(attr, struct f2fs_attr, attr);
143 
144 	return a->show ? a->show(a, sbi, buf) : 0;
145 }
146 
147 static ssize_t f2fs_attr_store(struct kobject *kobj, struct attribute *attr,
148 						const char *buf, size_t len)
149 {
150 	struct f2fs_sb_info *sbi = container_of(kobj, struct f2fs_sb_info,
151 									s_kobj);
152 	struct f2fs_attr *a = container_of(attr, struct f2fs_attr, attr);
153 
154 	return a->store ? a->store(a, sbi, buf, len) : 0;
155 }
156 
157 static void f2fs_sb_release(struct kobject *kobj)
158 {
159 	struct f2fs_sb_info *sbi = container_of(kobj, struct f2fs_sb_info,
160 								s_kobj);
161 	complete(&sbi->s_kobj_unregister);
162 }
163 
164 #define F2FS_ATTR_OFFSET(_struct_type, _name, _mode, _show, _store, _offset) \
165 static struct f2fs_attr f2fs_attr_##_name = {			\
166 	.attr = {.name = __stringify(_name), .mode = _mode },	\
167 	.show	= _show,					\
168 	.store	= _store,					\
169 	.struct_type = _struct_type,				\
170 	.offset = _offset					\
171 }
172 
173 #define F2FS_RW_ATTR(struct_type, struct_name, name, elname)	\
174 	F2FS_ATTR_OFFSET(struct_type, name, 0644,		\
175 		f2fs_sbi_show, f2fs_sbi_store,			\
176 		offsetof(struct struct_name, elname))
177 
178 F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_min_sleep_time, min_sleep_time);
179 F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_max_sleep_time, max_sleep_time);
180 F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_no_gc_sleep_time, no_gc_sleep_time);
181 F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_idle, gc_idle);
182 F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, reclaim_segments, rec_prefree_segments);
183 F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, max_small_discards, max_discards);
184 F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, ipu_policy, ipu_policy);
185 F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_ipu_util, min_ipu_util);
186 F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, max_victim_search, max_victim_search);
187 
188 #define ATTR_LIST(name) (&f2fs_attr_##name.attr)
189 static struct attribute *f2fs_attrs[] = {
190 	ATTR_LIST(gc_min_sleep_time),
191 	ATTR_LIST(gc_max_sleep_time),
192 	ATTR_LIST(gc_no_gc_sleep_time),
193 	ATTR_LIST(gc_idle),
194 	ATTR_LIST(reclaim_segments),
195 	ATTR_LIST(max_small_discards),
196 	ATTR_LIST(ipu_policy),
197 	ATTR_LIST(min_ipu_util),
198 	ATTR_LIST(max_victim_search),
199 	NULL,
200 };
201 
202 static const struct sysfs_ops f2fs_attr_ops = {
203 	.show	= f2fs_attr_show,
204 	.store	= f2fs_attr_store,
205 };
206 
207 static struct kobj_type f2fs_ktype = {
208 	.default_attrs	= f2fs_attrs,
209 	.sysfs_ops	= &f2fs_attr_ops,
210 	.release	= f2fs_sb_release,
211 };
212 
213 void f2fs_msg(struct super_block *sb, const char *level, const char *fmt, ...)
214 {
215 	struct va_format vaf;
216 	va_list args;
217 
218 	va_start(args, fmt);
219 	vaf.fmt = fmt;
220 	vaf.va = &args;
221 	printk("%sF2FS-fs (%s): %pV\n", level, sb->s_id, &vaf);
222 	va_end(args);
223 }
224 
225 static void init_once(void *foo)
226 {
227 	struct f2fs_inode_info *fi = (struct f2fs_inode_info *) foo;
228 
229 	inode_init_once(&fi->vfs_inode);
230 }
231 
232 static int parse_options(struct super_block *sb, char *options)
233 {
234 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
235 	substring_t args[MAX_OPT_ARGS];
236 	char *p, *name;
237 	int arg = 0;
238 
239 	if (!options)
240 		return 0;
241 
242 	while ((p = strsep(&options, ",")) != NULL) {
243 		int token;
244 		if (!*p)
245 			continue;
246 		/*
247 		 * Initialize args struct so we know whether arg was
248 		 * found; some options take optional arguments.
249 		 */
250 		args[0].to = args[0].from = NULL;
251 		token = match_token(p, f2fs_tokens, args);
252 
253 		switch (token) {
254 		case Opt_gc_background:
255 			name = match_strdup(&args[0]);
256 
257 			if (!name)
258 				return -ENOMEM;
259 			if (!strncmp(name, "on", 2))
260 				set_opt(sbi, BG_GC);
261 			else if (!strncmp(name, "off", 3))
262 				clear_opt(sbi, BG_GC);
263 			else {
264 				kfree(name);
265 				return -EINVAL;
266 			}
267 			kfree(name);
268 			break;
269 		case Opt_disable_roll_forward:
270 			set_opt(sbi, DISABLE_ROLL_FORWARD);
271 			break;
272 		case Opt_discard:
273 			set_opt(sbi, DISCARD);
274 			break;
275 		case Opt_noheap:
276 			set_opt(sbi, NOHEAP);
277 			break;
278 #ifdef CONFIG_F2FS_FS_XATTR
279 		case Opt_user_xattr:
280 			set_opt(sbi, XATTR_USER);
281 			break;
282 		case Opt_nouser_xattr:
283 			clear_opt(sbi, XATTR_USER);
284 			break;
285 		case Opt_inline_xattr:
286 			set_opt(sbi, INLINE_XATTR);
287 			break;
288 #else
289 		case Opt_user_xattr:
290 			f2fs_msg(sb, KERN_INFO,
291 				"user_xattr options not supported");
292 			break;
293 		case Opt_nouser_xattr:
294 			f2fs_msg(sb, KERN_INFO,
295 				"nouser_xattr options not supported");
296 			break;
297 		case Opt_inline_xattr:
298 			f2fs_msg(sb, KERN_INFO,
299 				"inline_xattr options not supported");
300 			break;
301 #endif
302 #ifdef CONFIG_F2FS_FS_POSIX_ACL
303 		case Opt_acl:
304 			set_opt(sbi, POSIX_ACL);
305 			break;
306 		case Opt_noacl:
307 			clear_opt(sbi, POSIX_ACL);
308 			break;
309 #else
310 		case Opt_acl:
311 			f2fs_msg(sb, KERN_INFO, "acl options not supported");
312 			break;
313 		case Opt_noacl:
314 			f2fs_msg(sb, KERN_INFO, "noacl options not supported");
315 			break;
316 #endif
317 		case Opt_active_logs:
318 			if (args->from && match_int(args, &arg))
319 				return -EINVAL;
320 			if (arg != 2 && arg != 4 && arg != NR_CURSEG_TYPE)
321 				return -EINVAL;
322 			sbi->active_logs = arg;
323 			break;
324 		case Opt_disable_ext_identify:
325 			set_opt(sbi, DISABLE_EXT_IDENTIFY);
326 			break;
327 		case Opt_inline_data:
328 			set_opt(sbi, INLINE_DATA);
329 			break;
330 		default:
331 			f2fs_msg(sb, KERN_ERR,
332 				"Unrecognized mount option \"%s\" or missing value",
333 				p);
334 			return -EINVAL;
335 		}
336 	}
337 	return 0;
338 }
339 
340 static struct inode *f2fs_alloc_inode(struct super_block *sb)
341 {
342 	struct f2fs_inode_info *fi;
343 
344 	fi = kmem_cache_alloc(f2fs_inode_cachep, GFP_F2FS_ZERO);
345 	if (!fi)
346 		return NULL;
347 
348 	init_once((void *) fi);
349 
350 	/* Initialize f2fs-specific inode info */
351 	fi->vfs_inode.i_version = 1;
352 	atomic_set(&fi->dirty_dents, 0);
353 	fi->i_current_depth = 1;
354 	fi->i_advise = 0;
355 	rwlock_init(&fi->ext.ext_lock);
356 
357 	set_inode_flag(fi, FI_NEW_INODE);
358 
359 	if (test_opt(F2FS_SB(sb), INLINE_XATTR))
360 		set_inode_flag(fi, FI_INLINE_XATTR);
361 
362 	return &fi->vfs_inode;
363 }
364 
365 static int f2fs_drop_inode(struct inode *inode)
366 {
367 	/*
368 	 * This is to avoid a deadlock condition like below.
369 	 * writeback_single_inode(inode)
370 	 *  - f2fs_write_data_page
371 	 *    - f2fs_gc -> iput -> evict
372 	 *       - inode_wait_for_writeback(inode)
373 	 */
374 	if (!inode_unhashed(inode) && inode->i_state & I_SYNC)
375 		return 0;
376 	return generic_drop_inode(inode);
377 }
378 
379 /*
380  * f2fs_dirty_inode() is called from __mark_inode_dirty()
381  *
382  * We should call set_dirty_inode to write the dirty inode through write_inode.
383  */
384 static void f2fs_dirty_inode(struct inode *inode, int flags)
385 {
386 	set_inode_flag(F2FS_I(inode), FI_DIRTY_INODE);
387 }
388 
389 static void f2fs_i_callback(struct rcu_head *head)
390 {
391 	struct inode *inode = container_of(head, struct inode, i_rcu);
392 	kmem_cache_free(f2fs_inode_cachep, F2FS_I(inode));
393 }
394 
395 static void f2fs_destroy_inode(struct inode *inode)
396 {
397 	call_rcu(&inode->i_rcu, f2fs_i_callback);
398 }
399 
400 static void f2fs_put_super(struct super_block *sb)
401 {
402 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
403 
404 	if (sbi->s_proc) {
405 		remove_proc_entry("segment_info", sbi->s_proc);
406 		remove_proc_entry(sb->s_id, f2fs_proc_root);
407 	}
408 	kobject_del(&sbi->s_kobj);
409 
410 	f2fs_destroy_stats(sbi);
411 	stop_gc_thread(sbi);
412 
413 	/* We don't need to do checkpoint when it's clean */
414 	if (sbi->s_dirty && get_pages(sbi, F2FS_DIRTY_NODES))
415 		write_checkpoint(sbi, true);
416 
417 	iput(sbi->node_inode);
418 	iput(sbi->meta_inode);
419 
420 	/* destroy f2fs internal modules */
421 	destroy_node_manager(sbi);
422 	destroy_segment_manager(sbi);
423 
424 	kfree(sbi->ckpt);
425 	kobject_put(&sbi->s_kobj);
426 	wait_for_completion(&sbi->s_kobj_unregister);
427 
428 	sb->s_fs_info = NULL;
429 	brelse(sbi->raw_super_buf);
430 	kfree(sbi);
431 }
432 
433 int f2fs_sync_fs(struct super_block *sb, int sync)
434 {
435 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
436 
437 	trace_f2fs_sync_fs(sb, sync);
438 
439 	if (!sbi->s_dirty && !get_pages(sbi, F2FS_DIRTY_NODES))
440 		return 0;
441 
442 	if (sync) {
443 		mutex_lock(&sbi->gc_mutex);
444 		write_checkpoint(sbi, false);
445 		mutex_unlock(&sbi->gc_mutex);
446 	} else {
447 		f2fs_balance_fs(sbi);
448 	}
449 
450 	return 0;
451 }
452 
453 static int f2fs_freeze(struct super_block *sb)
454 {
455 	int err;
456 
457 	if (f2fs_readonly(sb))
458 		return 0;
459 
460 	err = f2fs_sync_fs(sb, 1);
461 	return err;
462 }
463 
464 static int f2fs_unfreeze(struct super_block *sb)
465 {
466 	return 0;
467 }
468 
469 static int f2fs_statfs(struct dentry *dentry, struct kstatfs *buf)
470 {
471 	struct super_block *sb = dentry->d_sb;
472 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
473 	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
474 	block_t total_count, user_block_count, start_count, ovp_count;
475 
476 	total_count = le64_to_cpu(sbi->raw_super->block_count);
477 	user_block_count = sbi->user_block_count;
478 	start_count = le32_to_cpu(sbi->raw_super->segment0_blkaddr);
479 	ovp_count = SM_I(sbi)->ovp_segments << sbi->log_blocks_per_seg;
480 	buf->f_type = F2FS_SUPER_MAGIC;
481 	buf->f_bsize = sbi->blocksize;
482 
483 	buf->f_blocks = total_count - start_count;
484 	buf->f_bfree = buf->f_blocks - valid_user_blocks(sbi) - ovp_count;
485 	buf->f_bavail = user_block_count - valid_user_blocks(sbi);
486 
487 	buf->f_files = sbi->total_node_count;
488 	buf->f_ffree = sbi->total_node_count - valid_inode_count(sbi);
489 
490 	buf->f_namelen = F2FS_NAME_LEN;
491 	buf->f_fsid.val[0] = (u32)id;
492 	buf->f_fsid.val[1] = (u32)(id >> 32);
493 
494 	return 0;
495 }
496 
497 static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
498 {
499 	struct f2fs_sb_info *sbi = F2FS_SB(root->d_sb);
500 
501 	if (!(root->d_sb->s_flags & MS_RDONLY) && test_opt(sbi, BG_GC))
502 		seq_printf(seq, ",background_gc=%s", "on");
503 	else
504 		seq_printf(seq, ",background_gc=%s", "off");
505 	if (test_opt(sbi, DISABLE_ROLL_FORWARD))
506 		seq_puts(seq, ",disable_roll_forward");
507 	if (test_opt(sbi, DISCARD))
508 		seq_puts(seq, ",discard");
509 	if (test_opt(sbi, NOHEAP))
510 		seq_puts(seq, ",no_heap_alloc");
511 #ifdef CONFIG_F2FS_FS_XATTR
512 	if (test_opt(sbi, XATTR_USER))
513 		seq_puts(seq, ",user_xattr");
514 	else
515 		seq_puts(seq, ",nouser_xattr");
516 	if (test_opt(sbi, INLINE_XATTR))
517 		seq_puts(seq, ",inline_xattr");
518 #endif
519 #ifdef CONFIG_F2FS_FS_POSIX_ACL
520 	if (test_opt(sbi, POSIX_ACL))
521 		seq_puts(seq, ",acl");
522 	else
523 		seq_puts(seq, ",noacl");
524 #endif
525 	if (test_opt(sbi, DISABLE_EXT_IDENTIFY))
526 		seq_puts(seq, ",disable_ext_identify");
527 	if (test_opt(sbi, INLINE_DATA))
528 		seq_puts(seq, ",inline_data");
529 	seq_printf(seq, ",active_logs=%u", sbi->active_logs);
530 
531 	return 0;
532 }
533 
534 static int segment_info_seq_show(struct seq_file *seq, void *offset)
535 {
536 	struct super_block *sb = seq->private;
537 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
538 	unsigned int total_segs =
539 			le32_to_cpu(sbi->raw_super->segment_count_main);
540 	int i;
541 
542 	for (i = 0; i < total_segs; i++) {
543 		seq_printf(seq, "%u", get_valid_blocks(sbi, i, 1));
544 		if (i != 0 && (i % 10) == 0)
545 			seq_puts(seq, "\n");
546 		else
547 			seq_puts(seq, " ");
548 	}
549 	return 0;
550 }
551 
552 static int segment_info_open_fs(struct inode *inode, struct file *file)
553 {
554 	return single_open(file, segment_info_seq_show, PDE_DATA(inode));
555 }
556 
557 static const struct file_operations f2fs_seq_segment_info_fops = {
558 	.owner = THIS_MODULE,
559 	.open = segment_info_open_fs,
560 	.read = seq_read,
561 	.llseek = seq_lseek,
562 	.release = single_release,
563 };
564 
565 static int f2fs_remount(struct super_block *sb, int *flags, char *data)
566 {
567 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
568 	struct f2fs_mount_info org_mount_opt;
569 	int err, active_logs;
570 
571 	/*
572 	 * Save the old mount options in case we
573 	 * need to restore them.
574 	 */
575 	org_mount_opt = sbi->mount_opt;
576 	active_logs = sbi->active_logs;
577 
578 	/* parse mount options */
579 	err = parse_options(sb, data);
580 	if (err)
581 		goto restore_opts;
582 
583 	/*
584 	 * Previous and new state of filesystem is RO,
585 	 * so no point in checking GC conditions.
586 	 */
587 	if ((sb->s_flags & MS_RDONLY) && (*flags & MS_RDONLY))
588 		goto skip;
589 
590 	/*
591 	 * We stop the GC thread if FS is mounted as RO
592 	 * or if background_gc = off is passed in mount
593 	 * option. Also sync the filesystem.
594 	 */
595 	if ((*flags & MS_RDONLY) || !test_opt(sbi, BG_GC)) {
596 		if (sbi->gc_thread) {
597 			stop_gc_thread(sbi);
598 			f2fs_sync_fs(sb, 1);
599 		}
600 	} else if (test_opt(sbi, BG_GC) && !sbi->gc_thread) {
601 		err = start_gc_thread(sbi);
602 		if (err)
603 			goto restore_opts;
604 	}
605 skip:
606 	/* Update the POSIXACL Flag */
607 	 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
608 		(test_opt(sbi, POSIX_ACL) ? MS_POSIXACL : 0);
609 	return 0;
610 
611 restore_opts:
612 	sbi->mount_opt = org_mount_opt;
613 	sbi->active_logs = active_logs;
614 	return err;
615 }
616 
617 static struct super_operations f2fs_sops = {
618 	.alloc_inode	= f2fs_alloc_inode,
619 	.drop_inode	= f2fs_drop_inode,
620 	.destroy_inode	= f2fs_destroy_inode,
621 	.write_inode	= f2fs_write_inode,
622 	.dirty_inode	= f2fs_dirty_inode,
623 	.show_options	= f2fs_show_options,
624 	.evict_inode	= f2fs_evict_inode,
625 	.put_super	= f2fs_put_super,
626 	.sync_fs	= f2fs_sync_fs,
627 	.freeze_fs	= f2fs_freeze,
628 	.unfreeze_fs	= f2fs_unfreeze,
629 	.statfs		= f2fs_statfs,
630 	.remount_fs	= f2fs_remount,
631 };
632 
633 static struct inode *f2fs_nfs_get_inode(struct super_block *sb,
634 		u64 ino, u32 generation)
635 {
636 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
637 	struct inode *inode;
638 
639 	if (unlikely(ino < F2FS_ROOT_INO(sbi)))
640 		return ERR_PTR(-ESTALE);
641 
642 	/*
643 	 * f2fs_iget isn't quite right if the inode is currently unallocated!
644 	 * However f2fs_iget currently does appropriate checks to handle stale
645 	 * inodes so everything is OK.
646 	 */
647 	inode = f2fs_iget(sb, ino);
648 	if (IS_ERR(inode))
649 		return ERR_CAST(inode);
650 	if (unlikely(generation && inode->i_generation != generation)) {
651 		/* we didn't find the right inode.. */
652 		iput(inode);
653 		return ERR_PTR(-ESTALE);
654 	}
655 	return inode;
656 }
657 
658 static struct dentry *f2fs_fh_to_dentry(struct super_block *sb, struct fid *fid,
659 		int fh_len, int fh_type)
660 {
661 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
662 				    f2fs_nfs_get_inode);
663 }
664 
665 static struct dentry *f2fs_fh_to_parent(struct super_block *sb, struct fid *fid,
666 		int fh_len, int fh_type)
667 {
668 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
669 				    f2fs_nfs_get_inode);
670 }
671 
672 static const struct export_operations f2fs_export_ops = {
673 	.fh_to_dentry = f2fs_fh_to_dentry,
674 	.fh_to_parent = f2fs_fh_to_parent,
675 	.get_parent = f2fs_get_parent,
676 };
677 
678 static loff_t max_file_size(unsigned bits)
679 {
680 	loff_t result = (DEF_ADDRS_PER_INODE - F2FS_INLINE_XATTR_ADDRS);
681 	loff_t leaf_count = ADDRS_PER_BLOCK;
682 
683 	/* two direct node blocks */
684 	result += (leaf_count * 2);
685 
686 	/* two indirect node blocks */
687 	leaf_count *= NIDS_PER_BLOCK;
688 	result += (leaf_count * 2);
689 
690 	/* one double indirect node block */
691 	leaf_count *= NIDS_PER_BLOCK;
692 	result += leaf_count;
693 
694 	result <<= bits;
695 	return result;
696 }
697 
698 static int sanity_check_raw_super(struct super_block *sb,
699 			struct f2fs_super_block *raw_super)
700 {
701 	unsigned int blocksize;
702 
703 	if (F2FS_SUPER_MAGIC != le32_to_cpu(raw_super->magic)) {
704 		f2fs_msg(sb, KERN_INFO,
705 			"Magic Mismatch, valid(0x%x) - read(0x%x)",
706 			F2FS_SUPER_MAGIC, le32_to_cpu(raw_super->magic));
707 		return 1;
708 	}
709 
710 	/* Currently, support only 4KB page cache size */
711 	if (F2FS_BLKSIZE != PAGE_CACHE_SIZE) {
712 		f2fs_msg(sb, KERN_INFO,
713 			"Invalid page_cache_size (%lu), supports only 4KB\n",
714 			PAGE_CACHE_SIZE);
715 		return 1;
716 	}
717 
718 	/* Currently, support only 4KB block size */
719 	blocksize = 1 << le32_to_cpu(raw_super->log_blocksize);
720 	if (blocksize != F2FS_BLKSIZE) {
721 		f2fs_msg(sb, KERN_INFO,
722 			"Invalid blocksize (%u), supports only 4KB\n",
723 			blocksize);
724 		return 1;
725 	}
726 
727 	if (le32_to_cpu(raw_super->log_sectorsize) !=
728 					F2FS_LOG_SECTOR_SIZE) {
729 		f2fs_msg(sb, KERN_INFO, "Invalid log sectorsize");
730 		return 1;
731 	}
732 	if (le32_to_cpu(raw_super->log_sectors_per_block) !=
733 					F2FS_LOG_SECTORS_PER_BLOCK) {
734 		f2fs_msg(sb, KERN_INFO, "Invalid log sectors per block");
735 		return 1;
736 	}
737 	return 0;
738 }
739 
740 static int sanity_check_ckpt(struct f2fs_sb_info *sbi)
741 {
742 	unsigned int total, fsmeta;
743 	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
744 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
745 
746 	total = le32_to_cpu(raw_super->segment_count);
747 	fsmeta = le32_to_cpu(raw_super->segment_count_ckpt);
748 	fsmeta += le32_to_cpu(raw_super->segment_count_sit);
749 	fsmeta += le32_to_cpu(raw_super->segment_count_nat);
750 	fsmeta += le32_to_cpu(ckpt->rsvd_segment_count);
751 	fsmeta += le32_to_cpu(raw_super->segment_count_ssa);
752 
753 	if (unlikely(fsmeta >= total))
754 		return 1;
755 
756 	if (unlikely(is_set_ckpt_flags(ckpt, CP_ERROR_FLAG))) {
757 		f2fs_msg(sbi->sb, KERN_ERR, "A bug case: need to run fsck");
758 		return 1;
759 	}
760 	return 0;
761 }
762 
763 static void init_sb_info(struct f2fs_sb_info *sbi)
764 {
765 	struct f2fs_super_block *raw_super = sbi->raw_super;
766 	int i;
767 
768 	sbi->log_sectors_per_block =
769 		le32_to_cpu(raw_super->log_sectors_per_block);
770 	sbi->log_blocksize = le32_to_cpu(raw_super->log_blocksize);
771 	sbi->blocksize = 1 << sbi->log_blocksize;
772 	sbi->log_blocks_per_seg = le32_to_cpu(raw_super->log_blocks_per_seg);
773 	sbi->blocks_per_seg = 1 << sbi->log_blocks_per_seg;
774 	sbi->segs_per_sec = le32_to_cpu(raw_super->segs_per_sec);
775 	sbi->secs_per_zone = le32_to_cpu(raw_super->secs_per_zone);
776 	sbi->total_sections = le32_to_cpu(raw_super->section_count);
777 	sbi->total_node_count =
778 		(le32_to_cpu(raw_super->segment_count_nat) / 2)
779 			* sbi->blocks_per_seg * NAT_ENTRY_PER_BLOCK;
780 	sbi->root_ino_num = le32_to_cpu(raw_super->root_ino);
781 	sbi->node_ino_num = le32_to_cpu(raw_super->node_ino);
782 	sbi->meta_ino_num = le32_to_cpu(raw_super->meta_ino);
783 	sbi->cur_victim_sec = NULL_SECNO;
784 	sbi->max_victim_search = DEF_MAX_VICTIM_SEARCH;
785 
786 	for (i = 0; i < NR_COUNT_TYPE; i++)
787 		atomic_set(&sbi->nr_pages[i], 0);
788 }
789 
790 /*
791  * Read f2fs raw super block.
792  * Because we have two copies of super block, so read the first one at first,
793  * if the first one is invalid, move to read the second one.
794  */
795 static int read_raw_super_block(struct super_block *sb,
796 			struct f2fs_super_block **raw_super,
797 			struct buffer_head **raw_super_buf)
798 {
799 	int block = 0;
800 
801 retry:
802 	*raw_super_buf = sb_bread(sb, block);
803 	if (!*raw_super_buf) {
804 		f2fs_msg(sb, KERN_ERR, "Unable to read %dth superblock",
805 				block + 1);
806 		if (block == 0) {
807 			block++;
808 			goto retry;
809 		} else {
810 			return -EIO;
811 		}
812 	}
813 
814 	*raw_super = (struct f2fs_super_block *)
815 		((char *)(*raw_super_buf)->b_data + F2FS_SUPER_OFFSET);
816 
817 	/* sanity checking of raw super */
818 	if (sanity_check_raw_super(sb, *raw_super)) {
819 		brelse(*raw_super_buf);
820 		f2fs_msg(sb, KERN_ERR,
821 			"Can't find valid F2FS filesystem in %dth superblock",
822 								block + 1);
823 		if (block == 0) {
824 			block++;
825 			goto retry;
826 		} else {
827 			return -EINVAL;
828 		}
829 	}
830 
831 	return 0;
832 }
833 
834 static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
835 {
836 	struct f2fs_sb_info *sbi;
837 	struct f2fs_super_block *raw_super;
838 	struct buffer_head *raw_super_buf;
839 	struct inode *root;
840 	long err = -EINVAL;
841 	int i;
842 
843 	/* allocate memory for f2fs-specific super block info */
844 	sbi = kzalloc(sizeof(struct f2fs_sb_info), GFP_KERNEL);
845 	if (!sbi)
846 		return -ENOMEM;
847 
848 	/* set a block size */
849 	if (unlikely(!sb_set_blocksize(sb, F2FS_BLKSIZE))) {
850 		f2fs_msg(sb, KERN_ERR, "unable to set blocksize");
851 		goto free_sbi;
852 	}
853 
854 	err = read_raw_super_block(sb, &raw_super, &raw_super_buf);
855 	if (err)
856 		goto free_sbi;
857 
858 	sb->s_fs_info = sbi;
859 	/* init some FS parameters */
860 	sbi->active_logs = NR_CURSEG_TYPE;
861 
862 	set_opt(sbi, BG_GC);
863 
864 #ifdef CONFIG_F2FS_FS_XATTR
865 	set_opt(sbi, XATTR_USER);
866 #endif
867 #ifdef CONFIG_F2FS_FS_POSIX_ACL
868 	set_opt(sbi, POSIX_ACL);
869 #endif
870 	/* parse mount options */
871 	err = parse_options(sb, (char *)data);
872 	if (err)
873 		goto free_sb_buf;
874 
875 	sb->s_maxbytes = max_file_size(le32_to_cpu(raw_super->log_blocksize));
876 	sb->s_max_links = F2FS_LINK_MAX;
877 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
878 
879 	sb->s_op = &f2fs_sops;
880 	sb->s_xattr = f2fs_xattr_handlers;
881 	sb->s_export_op = &f2fs_export_ops;
882 	sb->s_magic = F2FS_SUPER_MAGIC;
883 	sb->s_time_gran = 1;
884 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
885 		(test_opt(sbi, POSIX_ACL) ? MS_POSIXACL : 0);
886 	memcpy(sb->s_uuid, raw_super->uuid, sizeof(raw_super->uuid));
887 
888 	/* init f2fs-specific super block info */
889 	sbi->sb = sb;
890 	sbi->raw_super = raw_super;
891 	sbi->raw_super_buf = raw_super_buf;
892 	mutex_init(&sbi->gc_mutex);
893 	mutex_init(&sbi->writepages);
894 	mutex_init(&sbi->cp_mutex);
895 	mutex_init(&sbi->node_write);
896 	sbi->por_doing = false;
897 	spin_lock_init(&sbi->stat_lock);
898 
899 	mutex_init(&sbi->read_io.io_mutex);
900 	sbi->read_io.sbi = sbi;
901 	sbi->read_io.bio = NULL;
902 	for (i = 0; i < NR_PAGE_TYPE; i++) {
903 		mutex_init(&sbi->write_io[i].io_mutex);
904 		sbi->write_io[i].sbi = sbi;
905 		sbi->write_io[i].bio = NULL;
906 	}
907 
908 	init_rwsem(&sbi->cp_rwsem);
909 	init_waitqueue_head(&sbi->cp_wait);
910 	init_sb_info(sbi);
911 
912 	/* get an inode for meta space */
913 	sbi->meta_inode = f2fs_iget(sb, F2FS_META_INO(sbi));
914 	if (IS_ERR(sbi->meta_inode)) {
915 		f2fs_msg(sb, KERN_ERR, "Failed to read F2FS meta data inode");
916 		err = PTR_ERR(sbi->meta_inode);
917 		goto free_sb_buf;
918 	}
919 
920 	err = get_valid_checkpoint(sbi);
921 	if (err) {
922 		f2fs_msg(sb, KERN_ERR, "Failed to get valid F2FS checkpoint");
923 		goto free_meta_inode;
924 	}
925 
926 	/* sanity checking of checkpoint */
927 	err = -EINVAL;
928 	if (sanity_check_ckpt(sbi)) {
929 		f2fs_msg(sb, KERN_ERR, "Invalid F2FS checkpoint");
930 		goto free_cp;
931 	}
932 
933 	sbi->total_valid_node_count =
934 				le32_to_cpu(sbi->ckpt->valid_node_count);
935 	sbi->total_valid_inode_count =
936 				le32_to_cpu(sbi->ckpt->valid_inode_count);
937 	sbi->user_block_count = le64_to_cpu(sbi->ckpt->user_block_count);
938 	sbi->total_valid_block_count =
939 				le64_to_cpu(sbi->ckpt->valid_block_count);
940 	sbi->last_valid_block_count = sbi->total_valid_block_count;
941 	sbi->alloc_valid_block_count = 0;
942 	INIT_LIST_HEAD(&sbi->dir_inode_list);
943 	spin_lock_init(&sbi->dir_inode_lock);
944 
945 	init_orphan_info(sbi);
946 
947 	/* setup f2fs internal modules */
948 	err = build_segment_manager(sbi);
949 	if (err) {
950 		f2fs_msg(sb, KERN_ERR,
951 			"Failed to initialize F2FS segment manager");
952 		goto free_sm;
953 	}
954 	err = build_node_manager(sbi);
955 	if (err) {
956 		f2fs_msg(sb, KERN_ERR,
957 			"Failed to initialize F2FS node manager");
958 		goto free_nm;
959 	}
960 
961 	build_gc_manager(sbi);
962 
963 	/* get an inode for node space */
964 	sbi->node_inode = f2fs_iget(sb, F2FS_NODE_INO(sbi));
965 	if (IS_ERR(sbi->node_inode)) {
966 		f2fs_msg(sb, KERN_ERR, "Failed to read node inode");
967 		err = PTR_ERR(sbi->node_inode);
968 		goto free_nm;
969 	}
970 
971 	/* if there are nt orphan nodes free them */
972 	recover_orphan_inodes(sbi);
973 
974 	/* read root inode and dentry */
975 	root = f2fs_iget(sb, F2FS_ROOT_INO(sbi));
976 	if (IS_ERR(root)) {
977 		f2fs_msg(sb, KERN_ERR, "Failed to read root inode");
978 		err = PTR_ERR(root);
979 		goto free_node_inode;
980 	}
981 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
982 		err = -EINVAL;
983 		goto free_root_inode;
984 	}
985 
986 	sb->s_root = d_make_root(root); /* allocate root dentry */
987 	if (!sb->s_root) {
988 		err = -ENOMEM;
989 		goto free_root_inode;
990 	}
991 
992 	/* recover fsynced data */
993 	if (!test_opt(sbi, DISABLE_ROLL_FORWARD)) {
994 		err = recover_fsync_data(sbi);
995 		if (err)
996 			f2fs_msg(sb, KERN_ERR,
997 				"Cannot recover all fsync data errno=%ld", err);
998 	}
999 
1000 	/*
1001 	 * If filesystem is not mounted as read-only then
1002 	 * do start the gc_thread.
1003 	 */
1004 	if (!(sb->s_flags & MS_RDONLY)) {
1005 		/* After POR, we can run background GC thread.*/
1006 		err = start_gc_thread(sbi);
1007 		if (err)
1008 			goto free_gc;
1009 	}
1010 
1011 	err = f2fs_build_stats(sbi);
1012 	if (err)
1013 		goto free_gc;
1014 
1015 	if (f2fs_proc_root)
1016 		sbi->s_proc = proc_mkdir(sb->s_id, f2fs_proc_root);
1017 
1018 	if (sbi->s_proc)
1019 		proc_create_data("segment_info", S_IRUGO, sbi->s_proc,
1020 				 &f2fs_seq_segment_info_fops, sb);
1021 
1022 	if (test_opt(sbi, DISCARD)) {
1023 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
1024 		if (!blk_queue_discard(q))
1025 			f2fs_msg(sb, KERN_WARNING,
1026 					"mounting with \"discard\" option, but "
1027 					"the device does not support discard");
1028 	}
1029 
1030 	sbi->s_kobj.kset = f2fs_kset;
1031 	init_completion(&sbi->s_kobj_unregister);
1032 	err = kobject_init_and_add(&sbi->s_kobj, &f2fs_ktype, NULL,
1033 							"%s", sb->s_id);
1034 	if (err)
1035 		goto fail;
1036 
1037 	return 0;
1038 fail:
1039 	if (sbi->s_proc) {
1040 		remove_proc_entry("segment_info", sbi->s_proc);
1041 		remove_proc_entry(sb->s_id, f2fs_proc_root);
1042 	}
1043 	f2fs_destroy_stats(sbi);
1044 free_gc:
1045 	stop_gc_thread(sbi);
1046 free_root_inode:
1047 	dput(sb->s_root);
1048 	sb->s_root = NULL;
1049 free_node_inode:
1050 	iput(sbi->node_inode);
1051 free_nm:
1052 	destroy_node_manager(sbi);
1053 free_sm:
1054 	destroy_segment_manager(sbi);
1055 free_cp:
1056 	kfree(sbi->ckpt);
1057 free_meta_inode:
1058 	make_bad_inode(sbi->meta_inode);
1059 	iput(sbi->meta_inode);
1060 free_sb_buf:
1061 	brelse(raw_super_buf);
1062 free_sbi:
1063 	kfree(sbi);
1064 	return err;
1065 }
1066 
1067 static struct dentry *f2fs_mount(struct file_system_type *fs_type, int flags,
1068 			const char *dev_name, void *data)
1069 {
1070 	return mount_bdev(fs_type, flags, dev_name, data, f2fs_fill_super);
1071 }
1072 
1073 static struct file_system_type f2fs_fs_type = {
1074 	.owner		= THIS_MODULE,
1075 	.name		= "f2fs",
1076 	.mount		= f2fs_mount,
1077 	.kill_sb	= kill_block_super,
1078 	.fs_flags	= FS_REQUIRES_DEV,
1079 };
1080 MODULE_ALIAS_FS("f2fs");
1081 
1082 static int __init init_inodecache(void)
1083 {
1084 	f2fs_inode_cachep = f2fs_kmem_cache_create("f2fs_inode_cache",
1085 			sizeof(struct f2fs_inode_info), NULL);
1086 	if (!f2fs_inode_cachep)
1087 		return -ENOMEM;
1088 	return 0;
1089 }
1090 
1091 static void destroy_inodecache(void)
1092 {
1093 	/*
1094 	 * Make sure all delayed rcu free inodes are flushed before we
1095 	 * destroy cache.
1096 	 */
1097 	rcu_barrier();
1098 	kmem_cache_destroy(f2fs_inode_cachep);
1099 }
1100 
1101 static int __init init_f2fs_fs(void)
1102 {
1103 	int err;
1104 
1105 	err = init_inodecache();
1106 	if (err)
1107 		goto fail;
1108 	err = create_node_manager_caches();
1109 	if (err)
1110 		goto free_inodecache;
1111 	err = create_segment_manager_caches();
1112 	if (err)
1113 		goto free_node_manager_caches;
1114 	err = create_gc_caches();
1115 	if (err)
1116 		goto free_segment_manager_caches;
1117 	err = create_checkpoint_caches();
1118 	if (err)
1119 		goto free_gc_caches;
1120 	f2fs_kset = kset_create_and_add("f2fs", NULL, fs_kobj);
1121 	if (!f2fs_kset) {
1122 		err = -ENOMEM;
1123 		goto free_checkpoint_caches;
1124 	}
1125 	err = register_filesystem(&f2fs_fs_type);
1126 	if (err)
1127 		goto free_kset;
1128 	f2fs_create_root_stats();
1129 	f2fs_proc_root = proc_mkdir("fs/f2fs", NULL);
1130 	return 0;
1131 
1132 free_kset:
1133 	kset_unregister(f2fs_kset);
1134 free_checkpoint_caches:
1135 	destroy_checkpoint_caches();
1136 free_gc_caches:
1137 	destroy_gc_caches();
1138 free_segment_manager_caches:
1139 	destroy_segment_manager_caches();
1140 free_node_manager_caches:
1141 	destroy_node_manager_caches();
1142 free_inodecache:
1143 	destroy_inodecache();
1144 fail:
1145 	return err;
1146 }
1147 
1148 static void __exit exit_f2fs_fs(void)
1149 {
1150 	remove_proc_entry("fs/f2fs", NULL);
1151 	f2fs_destroy_root_stats();
1152 	unregister_filesystem(&f2fs_fs_type);
1153 	destroy_checkpoint_caches();
1154 	destroy_gc_caches();
1155 	destroy_segment_manager_caches();
1156 	destroy_node_manager_caches();
1157 	destroy_inodecache();
1158 	kset_unregister(f2fs_kset);
1159 }
1160 
1161 module_init(init_f2fs_fs)
1162 module_exit(exit_f2fs_fs)
1163 
1164 MODULE_AUTHOR("Samsung Electronics's Praesto Team");
1165 MODULE_DESCRIPTION("Flash Friendly File System");
1166 MODULE_LICENSE("GPL");
1167