xref: /openbmc/linux/fs/f2fs/super.c (revision a0acdfe05a954363861a65eb537573ab417cb7ed)
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 };
78 
79 struct f2fs_attr {
80 	struct attribute attr;
81 	ssize_t (*show)(struct f2fs_attr *, struct f2fs_sb_info *, char *);
82 	ssize_t (*store)(struct f2fs_attr *, struct f2fs_sb_info *,
83 			 const char *, size_t);
84 	int struct_type;
85 	int offset;
86 };
87 
88 static unsigned char *__struct_ptr(struct f2fs_sb_info *sbi, int struct_type)
89 {
90 	if (struct_type == GC_THREAD)
91 		return (unsigned char *)sbi->gc_thread;
92 	else if (struct_type == SM_INFO)
93 		return (unsigned char *)SM_I(sbi);
94 	return NULL;
95 }
96 
97 static ssize_t f2fs_sbi_show(struct f2fs_attr *a,
98 			struct f2fs_sb_info *sbi, char *buf)
99 {
100 	unsigned char *ptr = NULL;
101 	unsigned int *ui;
102 
103 	ptr = __struct_ptr(sbi, a->struct_type);
104 	if (!ptr)
105 		return -EINVAL;
106 
107 	ui = (unsigned int *)(ptr + a->offset);
108 
109 	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
110 }
111 
112 static ssize_t f2fs_sbi_store(struct f2fs_attr *a,
113 			struct f2fs_sb_info *sbi,
114 			const char *buf, size_t count)
115 {
116 	unsigned char *ptr;
117 	unsigned long t;
118 	unsigned int *ui;
119 	ssize_t ret;
120 
121 	ptr = __struct_ptr(sbi, a->struct_type);
122 	if (!ptr)
123 		return -EINVAL;
124 
125 	ui = (unsigned int *)(ptr + a->offset);
126 
127 	ret = kstrtoul(skip_spaces(buf), 0, &t);
128 	if (ret < 0)
129 		return ret;
130 	*ui = t;
131 	return count;
132 }
133 
134 static ssize_t f2fs_attr_show(struct kobject *kobj,
135 				struct attribute *attr, char *buf)
136 {
137 	struct f2fs_sb_info *sbi = container_of(kobj, struct f2fs_sb_info,
138 								s_kobj);
139 	struct f2fs_attr *a = container_of(attr, struct f2fs_attr, attr);
140 
141 	return a->show ? a->show(a, sbi, buf) : 0;
142 }
143 
144 static ssize_t f2fs_attr_store(struct kobject *kobj, struct attribute *attr,
145 						const char *buf, size_t len)
146 {
147 	struct f2fs_sb_info *sbi = container_of(kobj, struct f2fs_sb_info,
148 									s_kobj);
149 	struct f2fs_attr *a = container_of(attr, struct f2fs_attr, attr);
150 
151 	return a->store ? a->store(a, sbi, buf, len) : 0;
152 }
153 
154 static void f2fs_sb_release(struct kobject *kobj)
155 {
156 	struct f2fs_sb_info *sbi = container_of(kobj, struct f2fs_sb_info,
157 								s_kobj);
158 	complete(&sbi->s_kobj_unregister);
159 }
160 
161 #define F2FS_ATTR_OFFSET(_struct_type, _name, _mode, _show, _store, _offset) \
162 static struct f2fs_attr f2fs_attr_##_name = {			\
163 	.attr = {.name = __stringify(_name), .mode = _mode },	\
164 	.show	= _show,					\
165 	.store	= _store,					\
166 	.struct_type = _struct_type,				\
167 	.offset = _offset					\
168 }
169 
170 #define F2FS_RW_ATTR(struct_type, struct_name, name, elname)	\
171 	F2FS_ATTR_OFFSET(struct_type, name, 0644,		\
172 		f2fs_sbi_show, f2fs_sbi_store,			\
173 		offsetof(struct struct_name, elname))
174 
175 F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_min_sleep_time, min_sleep_time);
176 F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_max_sleep_time, max_sleep_time);
177 F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_no_gc_sleep_time, no_gc_sleep_time);
178 F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_idle, gc_idle);
179 F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, reclaim_segments, rec_prefree_segments);
180 F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, max_small_discards, max_discards);
181 
182 #define ATTR_LIST(name) (&f2fs_attr_##name.attr)
183 static struct attribute *f2fs_attrs[] = {
184 	ATTR_LIST(gc_min_sleep_time),
185 	ATTR_LIST(gc_max_sleep_time),
186 	ATTR_LIST(gc_no_gc_sleep_time),
187 	ATTR_LIST(gc_idle),
188 	ATTR_LIST(reclaim_segments),
189 	ATTR_LIST(max_small_discards),
190 	NULL,
191 };
192 
193 static const struct sysfs_ops f2fs_attr_ops = {
194 	.show	= f2fs_attr_show,
195 	.store	= f2fs_attr_store,
196 };
197 
198 static struct kobj_type f2fs_ktype = {
199 	.default_attrs	= f2fs_attrs,
200 	.sysfs_ops	= &f2fs_attr_ops,
201 	.release	= f2fs_sb_release,
202 };
203 
204 void f2fs_msg(struct super_block *sb, const char *level, const char *fmt, ...)
205 {
206 	struct va_format vaf;
207 	va_list args;
208 
209 	va_start(args, fmt);
210 	vaf.fmt = fmt;
211 	vaf.va = &args;
212 	printk("%sF2FS-fs (%s): %pV\n", level, sb->s_id, &vaf);
213 	va_end(args);
214 }
215 
216 static void init_once(void *foo)
217 {
218 	struct f2fs_inode_info *fi = (struct f2fs_inode_info *) foo;
219 
220 	inode_init_once(&fi->vfs_inode);
221 }
222 
223 static int parse_options(struct super_block *sb, char *options)
224 {
225 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
226 	substring_t args[MAX_OPT_ARGS];
227 	char *p, *name;
228 	int arg = 0;
229 
230 	if (!options)
231 		return 0;
232 
233 	while ((p = strsep(&options, ",")) != NULL) {
234 		int token;
235 		if (!*p)
236 			continue;
237 		/*
238 		 * Initialize args struct so we know whether arg was
239 		 * found; some options take optional arguments.
240 		 */
241 		args[0].to = args[0].from = NULL;
242 		token = match_token(p, f2fs_tokens, args);
243 
244 		switch (token) {
245 		case Opt_gc_background:
246 			name = match_strdup(&args[0]);
247 
248 			if (!name)
249 				return -ENOMEM;
250 			if (!strncmp(name, "on", 2))
251 				set_opt(sbi, BG_GC);
252 			else if (!strncmp(name, "off", 3))
253 				clear_opt(sbi, BG_GC);
254 			else {
255 				kfree(name);
256 				return -EINVAL;
257 			}
258 			kfree(name);
259 			break;
260 		case Opt_disable_roll_forward:
261 			set_opt(sbi, DISABLE_ROLL_FORWARD);
262 			break;
263 		case Opt_discard:
264 			set_opt(sbi, DISCARD);
265 			break;
266 		case Opt_noheap:
267 			set_opt(sbi, NOHEAP);
268 			break;
269 #ifdef CONFIG_F2FS_FS_XATTR
270 		case Opt_user_xattr:
271 			set_opt(sbi, XATTR_USER);
272 			break;
273 		case Opt_nouser_xattr:
274 			clear_opt(sbi, XATTR_USER);
275 			break;
276 		case Opt_inline_xattr:
277 			set_opt(sbi, INLINE_XATTR);
278 			break;
279 #else
280 		case Opt_user_xattr:
281 			f2fs_msg(sb, KERN_INFO,
282 				"user_xattr options not supported");
283 			break;
284 		case Opt_nouser_xattr:
285 			f2fs_msg(sb, KERN_INFO,
286 				"nouser_xattr options not supported");
287 			break;
288 		case Opt_inline_xattr:
289 			f2fs_msg(sb, KERN_INFO,
290 				"inline_xattr options not supported");
291 			break;
292 #endif
293 #ifdef CONFIG_F2FS_FS_POSIX_ACL
294 		case Opt_acl:
295 			set_opt(sbi, POSIX_ACL);
296 			break;
297 		case Opt_noacl:
298 			clear_opt(sbi, POSIX_ACL);
299 			break;
300 #else
301 		case Opt_acl:
302 			f2fs_msg(sb, KERN_INFO, "acl options not supported");
303 			break;
304 		case Opt_noacl:
305 			f2fs_msg(sb, KERN_INFO, "noacl options not supported");
306 			break;
307 #endif
308 		case Opt_active_logs:
309 			if (args->from && match_int(args, &arg))
310 				return -EINVAL;
311 			if (arg != 2 && arg != 4 && arg != NR_CURSEG_TYPE)
312 				return -EINVAL;
313 			sbi->active_logs = arg;
314 			break;
315 		case Opt_disable_ext_identify:
316 			set_opt(sbi, DISABLE_EXT_IDENTIFY);
317 			break;
318 		case Opt_inline_data:
319 			set_opt(sbi, INLINE_DATA);
320 			break;
321 		default:
322 			f2fs_msg(sb, KERN_ERR,
323 				"Unrecognized mount option \"%s\" or missing value",
324 				p);
325 			return -EINVAL;
326 		}
327 	}
328 	return 0;
329 }
330 
331 static struct inode *f2fs_alloc_inode(struct super_block *sb)
332 {
333 	struct f2fs_inode_info *fi;
334 
335 	fi = kmem_cache_alloc(f2fs_inode_cachep, GFP_F2FS_ZERO);
336 	if (!fi)
337 		return NULL;
338 
339 	init_once((void *) fi);
340 
341 	/* Initialize f2fs-specific inode info */
342 	fi->vfs_inode.i_version = 1;
343 	atomic_set(&fi->dirty_dents, 0);
344 	fi->i_current_depth = 1;
345 	fi->i_advise = 0;
346 	rwlock_init(&fi->ext.ext_lock);
347 
348 	set_inode_flag(fi, FI_NEW_INODE);
349 
350 	if (test_opt(F2FS_SB(sb), INLINE_XATTR))
351 		set_inode_flag(fi, FI_INLINE_XATTR);
352 
353 	return &fi->vfs_inode;
354 }
355 
356 static int f2fs_drop_inode(struct inode *inode)
357 {
358 	/*
359 	 * This is to avoid a deadlock condition like below.
360 	 * writeback_single_inode(inode)
361 	 *  - f2fs_write_data_page
362 	 *    - f2fs_gc -> iput -> evict
363 	 *       - inode_wait_for_writeback(inode)
364 	 */
365 	if (!inode_unhashed(inode) && inode->i_state & I_SYNC)
366 		return 0;
367 	return generic_drop_inode(inode);
368 }
369 
370 /*
371  * f2fs_dirty_inode() is called from __mark_inode_dirty()
372  *
373  * We should call set_dirty_inode to write the dirty inode through write_inode.
374  */
375 static void f2fs_dirty_inode(struct inode *inode, int flags)
376 {
377 	set_inode_flag(F2FS_I(inode), FI_DIRTY_INODE);
378 }
379 
380 static void f2fs_i_callback(struct rcu_head *head)
381 {
382 	struct inode *inode = container_of(head, struct inode, i_rcu);
383 	kmem_cache_free(f2fs_inode_cachep, F2FS_I(inode));
384 }
385 
386 static void f2fs_destroy_inode(struct inode *inode)
387 {
388 	call_rcu(&inode->i_rcu, f2fs_i_callback);
389 }
390 
391 static void f2fs_put_super(struct super_block *sb)
392 {
393 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
394 
395 	if (sbi->s_proc) {
396 		remove_proc_entry("segment_info", sbi->s_proc);
397 		remove_proc_entry(sb->s_id, f2fs_proc_root);
398 	}
399 	kobject_del(&sbi->s_kobj);
400 
401 	f2fs_destroy_stats(sbi);
402 	stop_gc_thread(sbi);
403 
404 	/* We don't need to do checkpoint when it's clean */
405 	if (sbi->s_dirty && get_pages(sbi, F2FS_DIRTY_NODES))
406 		write_checkpoint(sbi, true);
407 
408 	iput(sbi->node_inode);
409 	iput(sbi->meta_inode);
410 
411 	/* destroy f2fs internal modules */
412 	destroy_node_manager(sbi);
413 	destroy_segment_manager(sbi);
414 
415 	kfree(sbi->ckpt);
416 	kobject_put(&sbi->s_kobj);
417 	wait_for_completion(&sbi->s_kobj_unregister);
418 
419 	sb->s_fs_info = NULL;
420 	brelse(sbi->raw_super_buf);
421 	kfree(sbi);
422 }
423 
424 int f2fs_sync_fs(struct super_block *sb, int sync)
425 {
426 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
427 
428 	trace_f2fs_sync_fs(sb, sync);
429 
430 	if (!sbi->s_dirty && !get_pages(sbi, F2FS_DIRTY_NODES))
431 		return 0;
432 
433 	if (sync) {
434 		mutex_lock(&sbi->gc_mutex);
435 		write_checkpoint(sbi, false);
436 		mutex_unlock(&sbi->gc_mutex);
437 	} else {
438 		f2fs_balance_fs(sbi);
439 	}
440 
441 	return 0;
442 }
443 
444 static int f2fs_freeze(struct super_block *sb)
445 {
446 	int err;
447 
448 	if (f2fs_readonly(sb))
449 		return 0;
450 
451 	err = f2fs_sync_fs(sb, 1);
452 	return err;
453 }
454 
455 static int f2fs_unfreeze(struct super_block *sb)
456 {
457 	return 0;
458 }
459 
460 static int f2fs_statfs(struct dentry *dentry, struct kstatfs *buf)
461 {
462 	struct super_block *sb = dentry->d_sb;
463 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
464 	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
465 	block_t total_count, user_block_count, start_count, ovp_count;
466 
467 	total_count = le64_to_cpu(sbi->raw_super->block_count);
468 	user_block_count = sbi->user_block_count;
469 	start_count = le32_to_cpu(sbi->raw_super->segment0_blkaddr);
470 	ovp_count = SM_I(sbi)->ovp_segments << sbi->log_blocks_per_seg;
471 	buf->f_type = F2FS_SUPER_MAGIC;
472 	buf->f_bsize = sbi->blocksize;
473 
474 	buf->f_blocks = total_count - start_count;
475 	buf->f_bfree = buf->f_blocks - valid_user_blocks(sbi) - ovp_count;
476 	buf->f_bavail = user_block_count - valid_user_blocks(sbi);
477 
478 	buf->f_files = sbi->total_node_count;
479 	buf->f_ffree = sbi->total_node_count - valid_inode_count(sbi);
480 
481 	buf->f_namelen = F2FS_NAME_LEN;
482 	buf->f_fsid.val[0] = (u32)id;
483 	buf->f_fsid.val[1] = (u32)(id >> 32);
484 
485 	return 0;
486 }
487 
488 static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
489 {
490 	struct f2fs_sb_info *sbi = F2FS_SB(root->d_sb);
491 
492 	if (!(root->d_sb->s_flags & MS_RDONLY) && test_opt(sbi, BG_GC))
493 		seq_printf(seq, ",background_gc=%s", "on");
494 	else
495 		seq_printf(seq, ",background_gc=%s", "off");
496 	if (test_opt(sbi, DISABLE_ROLL_FORWARD))
497 		seq_puts(seq, ",disable_roll_forward");
498 	if (test_opt(sbi, DISCARD))
499 		seq_puts(seq, ",discard");
500 	if (test_opt(sbi, NOHEAP))
501 		seq_puts(seq, ",no_heap_alloc");
502 #ifdef CONFIG_F2FS_FS_XATTR
503 	if (test_opt(sbi, XATTR_USER))
504 		seq_puts(seq, ",user_xattr");
505 	else
506 		seq_puts(seq, ",nouser_xattr");
507 	if (test_opt(sbi, INLINE_XATTR))
508 		seq_puts(seq, ",inline_xattr");
509 #endif
510 #ifdef CONFIG_F2FS_FS_POSIX_ACL
511 	if (test_opt(sbi, POSIX_ACL))
512 		seq_puts(seq, ",acl");
513 	else
514 		seq_puts(seq, ",noacl");
515 #endif
516 	if (test_opt(sbi, DISABLE_EXT_IDENTIFY))
517 		seq_puts(seq, ",disable_ext_identify");
518 	if (test_opt(sbi, INLINE_DATA))
519 		seq_puts(seq, ",inline_data");
520 	seq_printf(seq, ",active_logs=%u", sbi->active_logs);
521 
522 	return 0;
523 }
524 
525 static int segment_info_seq_show(struct seq_file *seq, void *offset)
526 {
527 	struct super_block *sb = seq->private;
528 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
529 	unsigned int total_segs = le32_to_cpu(sbi->raw_super->segment_count_main);
530 	int i;
531 
532 	for (i = 0; i < total_segs; i++) {
533 		seq_printf(seq, "%u", get_valid_blocks(sbi, i, 1));
534 		if (i != 0 && (i % 10) == 0)
535 			seq_puts(seq, "\n");
536 		else
537 			seq_puts(seq, " ");
538 	}
539 	return 0;
540 }
541 
542 static int segment_info_open_fs(struct inode *inode, struct file *file)
543 {
544 	return single_open(file, segment_info_seq_show, PDE_DATA(inode));
545 }
546 
547 static const struct file_operations f2fs_seq_segment_info_fops = {
548 	.owner = THIS_MODULE,
549 	.open = segment_info_open_fs,
550 	.read = seq_read,
551 	.llseek = seq_lseek,
552 	.release = single_release,
553 };
554 
555 static int f2fs_remount(struct super_block *sb, int *flags, char *data)
556 {
557 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
558 	struct f2fs_mount_info org_mount_opt;
559 	int err, active_logs;
560 
561 	/*
562 	 * Save the old mount options in case we
563 	 * need to restore them.
564 	 */
565 	org_mount_opt = sbi->mount_opt;
566 	active_logs = sbi->active_logs;
567 
568 	/* parse mount options */
569 	err = parse_options(sb, data);
570 	if (err)
571 		goto restore_opts;
572 
573 	/*
574 	 * Previous and new state of filesystem is RO,
575 	 * so no point in checking GC conditions.
576 	 */
577 	if ((sb->s_flags & MS_RDONLY) && (*flags & MS_RDONLY))
578 		goto skip;
579 
580 	/*
581 	 * We stop the GC thread if FS is mounted as RO
582 	 * or if background_gc = off is passed in mount
583 	 * option. Also sync the filesystem.
584 	 */
585 	if ((*flags & MS_RDONLY) || !test_opt(sbi, BG_GC)) {
586 		if (sbi->gc_thread) {
587 			stop_gc_thread(sbi);
588 			f2fs_sync_fs(sb, 1);
589 		}
590 	} else if (test_opt(sbi, BG_GC) && !sbi->gc_thread) {
591 		err = start_gc_thread(sbi);
592 		if (err)
593 			goto restore_opts;
594 	}
595 skip:
596 	/* Update the POSIXACL Flag */
597 	 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
598 		(test_opt(sbi, POSIX_ACL) ? MS_POSIXACL : 0);
599 	return 0;
600 
601 restore_opts:
602 	sbi->mount_opt = org_mount_opt;
603 	sbi->active_logs = active_logs;
604 	return err;
605 }
606 
607 static struct super_operations f2fs_sops = {
608 	.alloc_inode	= f2fs_alloc_inode,
609 	.drop_inode	= f2fs_drop_inode,
610 	.destroy_inode	= f2fs_destroy_inode,
611 	.write_inode	= f2fs_write_inode,
612 	.dirty_inode	= f2fs_dirty_inode,
613 	.show_options	= f2fs_show_options,
614 	.evict_inode	= f2fs_evict_inode,
615 	.put_super	= f2fs_put_super,
616 	.sync_fs	= f2fs_sync_fs,
617 	.freeze_fs	= f2fs_freeze,
618 	.unfreeze_fs	= f2fs_unfreeze,
619 	.statfs		= f2fs_statfs,
620 	.remount_fs	= f2fs_remount,
621 };
622 
623 static struct inode *f2fs_nfs_get_inode(struct super_block *sb,
624 		u64 ino, u32 generation)
625 {
626 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
627 	struct inode *inode;
628 
629 	if (ino < F2FS_ROOT_INO(sbi))
630 		return ERR_PTR(-ESTALE);
631 
632 	/*
633 	 * f2fs_iget isn't quite right if the inode is currently unallocated!
634 	 * However f2fs_iget currently does appropriate checks to handle stale
635 	 * inodes so everything is OK.
636 	 */
637 	inode = f2fs_iget(sb, ino);
638 	if (IS_ERR(inode))
639 		return ERR_CAST(inode);
640 	if (generation && inode->i_generation != generation) {
641 		/* we didn't find the right inode.. */
642 		iput(inode);
643 		return ERR_PTR(-ESTALE);
644 	}
645 	return inode;
646 }
647 
648 static struct dentry *f2fs_fh_to_dentry(struct super_block *sb, struct fid *fid,
649 		int fh_len, int fh_type)
650 {
651 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
652 				    f2fs_nfs_get_inode);
653 }
654 
655 static struct dentry *f2fs_fh_to_parent(struct super_block *sb, struct fid *fid,
656 		int fh_len, int fh_type)
657 {
658 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
659 				    f2fs_nfs_get_inode);
660 }
661 
662 static const struct export_operations f2fs_export_ops = {
663 	.fh_to_dentry = f2fs_fh_to_dentry,
664 	.fh_to_parent = f2fs_fh_to_parent,
665 	.get_parent = f2fs_get_parent,
666 };
667 
668 static loff_t max_file_size(unsigned bits)
669 {
670 	loff_t result = (DEF_ADDRS_PER_INODE - F2FS_INLINE_XATTR_ADDRS);
671 	loff_t leaf_count = ADDRS_PER_BLOCK;
672 
673 	/* two direct node blocks */
674 	result += (leaf_count * 2);
675 
676 	/* two indirect node blocks */
677 	leaf_count *= NIDS_PER_BLOCK;
678 	result += (leaf_count * 2);
679 
680 	/* one double indirect node block */
681 	leaf_count *= NIDS_PER_BLOCK;
682 	result += leaf_count;
683 
684 	result <<= bits;
685 	return result;
686 }
687 
688 static int sanity_check_raw_super(struct super_block *sb,
689 			struct f2fs_super_block *raw_super)
690 {
691 	unsigned int blocksize;
692 
693 	if (F2FS_SUPER_MAGIC != le32_to_cpu(raw_super->magic)) {
694 		f2fs_msg(sb, KERN_INFO,
695 			"Magic Mismatch, valid(0x%x) - read(0x%x)",
696 			F2FS_SUPER_MAGIC, le32_to_cpu(raw_super->magic));
697 		return 1;
698 	}
699 
700 	/* Currently, support only 4KB page cache size */
701 	if (F2FS_BLKSIZE != PAGE_CACHE_SIZE) {
702 		f2fs_msg(sb, KERN_INFO,
703 			"Invalid page_cache_size (%lu), supports only 4KB\n",
704 			PAGE_CACHE_SIZE);
705 		return 1;
706 	}
707 
708 	/* Currently, support only 4KB block size */
709 	blocksize = 1 << le32_to_cpu(raw_super->log_blocksize);
710 	if (blocksize != F2FS_BLKSIZE) {
711 		f2fs_msg(sb, KERN_INFO,
712 			"Invalid blocksize (%u), supports only 4KB\n",
713 			blocksize);
714 		return 1;
715 	}
716 
717 	if (le32_to_cpu(raw_super->log_sectorsize) !=
718 					F2FS_LOG_SECTOR_SIZE) {
719 		f2fs_msg(sb, KERN_INFO, "Invalid log sectorsize");
720 		return 1;
721 	}
722 	if (le32_to_cpu(raw_super->log_sectors_per_block) !=
723 					F2FS_LOG_SECTORS_PER_BLOCK) {
724 		f2fs_msg(sb, KERN_INFO, "Invalid log sectors per block");
725 		return 1;
726 	}
727 	return 0;
728 }
729 
730 static int sanity_check_ckpt(struct f2fs_sb_info *sbi)
731 {
732 	unsigned int total, fsmeta;
733 	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
734 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
735 
736 	total = le32_to_cpu(raw_super->segment_count);
737 	fsmeta = le32_to_cpu(raw_super->segment_count_ckpt);
738 	fsmeta += le32_to_cpu(raw_super->segment_count_sit);
739 	fsmeta += le32_to_cpu(raw_super->segment_count_nat);
740 	fsmeta += le32_to_cpu(ckpt->rsvd_segment_count);
741 	fsmeta += le32_to_cpu(raw_super->segment_count_ssa);
742 
743 	if (fsmeta >= total)
744 		return 1;
745 
746 	if (is_set_ckpt_flags(ckpt, CP_ERROR_FLAG)) {
747 		f2fs_msg(sbi->sb, KERN_ERR, "A bug case: need to run fsck");
748 		return 1;
749 	}
750 	return 0;
751 }
752 
753 static void init_sb_info(struct f2fs_sb_info *sbi)
754 {
755 	struct f2fs_super_block *raw_super = sbi->raw_super;
756 	int i;
757 
758 	sbi->log_sectors_per_block =
759 		le32_to_cpu(raw_super->log_sectors_per_block);
760 	sbi->log_blocksize = le32_to_cpu(raw_super->log_blocksize);
761 	sbi->blocksize = 1 << sbi->log_blocksize;
762 	sbi->log_blocks_per_seg = le32_to_cpu(raw_super->log_blocks_per_seg);
763 	sbi->blocks_per_seg = 1 << sbi->log_blocks_per_seg;
764 	sbi->segs_per_sec = le32_to_cpu(raw_super->segs_per_sec);
765 	sbi->secs_per_zone = le32_to_cpu(raw_super->secs_per_zone);
766 	sbi->total_sections = le32_to_cpu(raw_super->section_count);
767 	sbi->total_node_count =
768 		(le32_to_cpu(raw_super->segment_count_nat) / 2)
769 			* sbi->blocks_per_seg * NAT_ENTRY_PER_BLOCK;
770 	sbi->root_ino_num = le32_to_cpu(raw_super->root_ino);
771 	sbi->node_ino_num = le32_to_cpu(raw_super->node_ino);
772 	sbi->meta_ino_num = le32_to_cpu(raw_super->meta_ino);
773 	sbi->cur_victim_sec = NULL_SECNO;
774 
775 	for (i = 0; i < NR_COUNT_TYPE; i++)
776 		atomic_set(&sbi->nr_pages[i], 0);
777 }
778 
779 /*
780  * Read f2fs raw super block.
781  * Because we have two copies of super block, so read the first one at first,
782  * if the first one is invalid, move to read the second one.
783  */
784 static int read_raw_super_block(struct super_block *sb,
785 			struct f2fs_super_block **raw_super,
786 			struct buffer_head **raw_super_buf)
787 {
788 	int block = 0;
789 
790 retry:
791 	*raw_super_buf = sb_bread(sb, block);
792 	if (!*raw_super_buf) {
793 		f2fs_msg(sb, KERN_ERR, "Unable to read %dth superblock",
794 				block + 1);
795 		if (block == 0) {
796 			block++;
797 			goto retry;
798 		} else {
799 			return -EIO;
800 		}
801 	}
802 
803 	*raw_super = (struct f2fs_super_block *)
804 		((char *)(*raw_super_buf)->b_data + F2FS_SUPER_OFFSET);
805 
806 	/* sanity checking of raw super */
807 	if (sanity_check_raw_super(sb, *raw_super)) {
808 		brelse(*raw_super_buf);
809 		f2fs_msg(sb, KERN_ERR, "Can't find a valid F2FS filesystem "
810 				"in %dth superblock", block + 1);
811 		if(block == 0) {
812 			block++;
813 			goto retry;
814 		} else {
815 			return -EINVAL;
816 		}
817 	}
818 
819 	return 0;
820 }
821 
822 static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
823 {
824 	struct f2fs_sb_info *sbi;
825 	struct f2fs_super_block *raw_super;
826 	struct buffer_head *raw_super_buf;
827 	struct inode *root;
828 	long err = -EINVAL;
829 	int i;
830 
831 	/* allocate memory for f2fs-specific super block info */
832 	sbi = kzalloc(sizeof(struct f2fs_sb_info), GFP_KERNEL);
833 	if (!sbi)
834 		return -ENOMEM;
835 
836 	/* set a block size */
837 	if (!sb_set_blocksize(sb, F2FS_BLKSIZE)) {
838 		f2fs_msg(sb, KERN_ERR, "unable to set blocksize");
839 		goto free_sbi;
840 	}
841 
842 	err = read_raw_super_block(sb, &raw_super, &raw_super_buf);
843 	if (err)
844 		goto free_sbi;
845 
846 	sb->s_fs_info = sbi;
847 	/* init some FS parameters */
848 	sbi->active_logs = NR_CURSEG_TYPE;
849 
850 	set_opt(sbi, BG_GC);
851 
852 #ifdef CONFIG_F2FS_FS_XATTR
853 	set_opt(sbi, XATTR_USER);
854 #endif
855 #ifdef CONFIG_F2FS_FS_POSIX_ACL
856 	set_opt(sbi, POSIX_ACL);
857 #endif
858 	/* parse mount options */
859 	err = parse_options(sb, (char *)data);
860 	if (err)
861 		goto free_sb_buf;
862 
863 	sb->s_maxbytes = max_file_size(le32_to_cpu(raw_super->log_blocksize));
864 	sb->s_max_links = F2FS_LINK_MAX;
865 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
866 
867 	sb->s_op = &f2fs_sops;
868 	sb->s_xattr = f2fs_xattr_handlers;
869 	sb->s_export_op = &f2fs_export_ops;
870 	sb->s_magic = F2FS_SUPER_MAGIC;
871 	sb->s_time_gran = 1;
872 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
873 		(test_opt(sbi, POSIX_ACL) ? MS_POSIXACL : 0);
874 	memcpy(sb->s_uuid, raw_super->uuid, sizeof(raw_super->uuid));
875 
876 	/* init f2fs-specific super block info */
877 	sbi->sb = sb;
878 	sbi->raw_super = raw_super;
879 	sbi->raw_super_buf = raw_super_buf;
880 	mutex_init(&sbi->gc_mutex);
881 	mutex_init(&sbi->writepages);
882 	mutex_init(&sbi->cp_mutex);
883 	mutex_init(&sbi->node_write);
884 	sbi->por_doing = false;
885 	spin_lock_init(&sbi->stat_lock);
886 
887 	mutex_init(&sbi->read_io.io_mutex);
888 	for (i = 0; i < NR_PAGE_TYPE; i++)
889 		mutex_init(&sbi->write_io[i].io_mutex);
890 
891 	init_rwsem(&sbi->cp_rwsem);
892 	init_waitqueue_head(&sbi->cp_wait);
893 	init_sb_info(sbi);
894 
895 	/* get an inode for meta space */
896 	sbi->meta_inode = f2fs_iget(sb, F2FS_META_INO(sbi));
897 	if (IS_ERR(sbi->meta_inode)) {
898 		f2fs_msg(sb, KERN_ERR, "Failed to read F2FS meta data inode");
899 		err = PTR_ERR(sbi->meta_inode);
900 		goto free_sb_buf;
901 	}
902 
903 	err = get_valid_checkpoint(sbi);
904 	if (err) {
905 		f2fs_msg(sb, KERN_ERR, "Failed to get valid F2FS checkpoint");
906 		goto free_meta_inode;
907 	}
908 
909 	/* sanity checking of checkpoint */
910 	err = -EINVAL;
911 	if (sanity_check_ckpt(sbi)) {
912 		f2fs_msg(sb, KERN_ERR, "Invalid F2FS checkpoint");
913 		goto free_cp;
914 	}
915 
916 	sbi->total_valid_node_count =
917 				le32_to_cpu(sbi->ckpt->valid_node_count);
918 	sbi->total_valid_inode_count =
919 				le32_to_cpu(sbi->ckpt->valid_inode_count);
920 	sbi->user_block_count = le64_to_cpu(sbi->ckpt->user_block_count);
921 	sbi->total_valid_block_count =
922 				le64_to_cpu(sbi->ckpt->valid_block_count);
923 	sbi->last_valid_block_count = sbi->total_valid_block_count;
924 	sbi->alloc_valid_block_count = 0;
925 	INIT_LIST_HEAD(&sbi->dir_inode_list);
926 	spin_lock_init(&sbi->dir_inode_lock);
927 
928 	init_orphan_info(sbi);
929 
930 	/* setup f2fs internal modules */
931 	err = build_segment_manager(sbi);
932 	if (err) {
933 		f2fs_msg(sb, KERN_ERR,
934 			"Failed to initialize F2FS segment manager");
935 		goto free_sm;
936 	}
937 	err = build_node_manager(sbi);
938 	if (err) {
939 		f2fs_msg(sb, KERN_ERR,
940 			"Failed to initialize F2FS node manager");
941 		goto free_nm;
942 	}
943 
944 	build_gc_manager(sbi);
945 
946 	/* get an inode for node space */
947 	sbi->node_inode = f2fs_iget(sb, F2FS_NODE_INO(sbi));
948 	if (IS_ERR(sbi->node_inode)) {
949 		f2fs_msg(sb, KERN_ERR, "Failed to read node inode");
950 		err = PTR_ERR(sbi->node_inode);
951 		goto free_nm;
952 	}
953 
954 	/* if there are nt orphan nodes free them */
955 	recover_orphan_inodes(sbi);
956 
957 	/* read root inode and dentry */
958 	root = f2fs_iget(sb, F2FS_ROOT_INO(sbi));
959 	if (IS_ERR(root)) {
960 		f2fs_msg(sb, KERN_ERR, "Failed to read root inode");
961 		err = PTR_ERR(root);
962 		goto free_node_inode;
963 	}
964 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
965 		err = -EINVAL;
966 		goto free_root_inode;
967 	}
968 
969 	sb->s_root = d_make_root(root); /* allocate root dentry */
970 	if (!sb->s_root) {
971 		err = -ENOMEM;
972 		goto free_root_inode;
973 	}
974 
975 	/* recover fsynced data */
976 	if (!test_opt(sbi, DISABLE_ROLL_FORWARD)) {
977 		err = recover_fsync_data(sbi);
978 		if (err)
979 			f2fs_msg(sb, KERN_ERR,
980 				"Cannot recover all fsync data errno=%ld", err);
981 	}
982 
983 	/*
984 	 * If filesystem is not mounted as read-only then
985 	 * do start the gc_thread.
986 	 */
987 	if (!(sb->s_flags & MS_RDONLY)) {
988 		/* After POR, we can run background GC thread.*/
989 		err = start_gc_thread(sbi);
990 		if (err)
991 			goto free_gc;
992 	}
993 
994 	err = f2fs_build_stats(sbi);
995 	if (err)
996 		goto free_gc;
997 
998 	if (f2fs_proc_root)
999 		sbi->s_proc = proc_mkdir(sb->s_id, f2fs_proc_root);
1000 
1001 	if (sbi->s_proc)
1002 		proc_create_data("segment_info", S_IRUGO, sbi->s_proc,
1003 				 &f2fs_seq_segment_info_fops, sb);
1004 
1005 	if (test_opt(sbi, DISCARD)) {
1006 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
1007 		if (!blk_queue_discard(q))
1008 			f2fs_msg(sb, KERN_WARNING,
1009 					"mounting with \"discard\" option, but "
1010 					"the device does not support discard");
1011 	}
1012 
1013 	sbi->s_kobj.kset = f2fs_kset;
1014 	init_completion(&sbi->s_kobj_unregister);
1015 	err = kobject_init_and_add(&sbi->s_kobj, &f2fs_ktype, NULL,
1016 							"%s", sb->s_id);
1017 	if (err)
1018 		goto fail;
1019 
1020 	return 0;
1021 fail:
1022 	if (sbi->s_proc) {
1023 		remove_proc_entry("segment_info", sbi->s_proc);
1024 		remove_proc_entry(sb->s_id, f2fs_proc_root);
1025 	}
1026 	f2fs_destroy_stats(sbi);
1027 free_gc:
1028 	stop_gc_thread(sbi);
1029 free_root_inode:
1030 	dput(sb->s_root);
1031 	sb->s_root = NULL;
1032 free_node_inode:
1033 	iput(sbi->node_inode);
1034 free_nm:
1035 	destroy_node_manager(sbi);
1036 free_sm:
1037 	destroy_segment_manager(sbi);
1038 free_cp:
1039 	kfree(sbi->ckpt);
1040 free_meta_inode:
1041 	make_bad_inode(sbi->meta_inode);
1042 	iput(sbi->meta_inode);
1043 free_sb_buf:
1044 	brelse(raw_super_buf);
1045 free_sbi:
1046 	kfree(sbi);
1047 	return err;
1048 }
1049 
1050 static struct dentry *f2fs_mount(struct file_system_type *fs_type, int flags,
1051 			const char *dev_name, void *data)
1052 {
1053 	return mount_bdev(fs_type, flags, dev_name, data, f2fs_fill_super);
1054 }
1055 
1056 static struct file_system_type f2fs_fs_type = {
1057 	.owner		= THIS_MODULE,
1058 	.name		= "f2fs",
1059 	.mount		= f2fs_mount,
1060 	.kill_sb	= kill_block_super,
1061 	.fs_flags	= FS_REQUIRES_DEV,
1062 };
1063 MODULE_ALIAS_FS("f2fs");
1064 
1065 static int __init init_inodecache(void)
1066 {
1067 	f2fs_inode_cachep = f2fs_kmem_cache_create("f2fs_inode_cache",
1068 			sizeof(struct f2fs_inode_info), NULL);
1069 	if (f2fs_inode_cachep == NULL)
1070 		return -ENOMEM;
1071 	return 0;
1072 }
1073 
1074 static void destroy_inodecache(void)
1075 {
1076 	/*
1077 	 * Make sure all delayed rcu free inodes are flushed before we
1078 	 * destroy cache.
1079 	 */
1080 	rcu_barrier();
1081 	kmem_cache_destroy(f2fs_inode_cachep);
1082 }
1083 
1084 static int __init init_f2fs_fs(void)
1085 {
1086 	int err;
1087 
1088 	err = init_inodecache();
1089 	if (err)
1090 		goto fail;
1091 	err = create_node_manager_caches();
1092 	if (err)
1093 		goto free_inodecache;
1094 	err = create_segment_manager_caches();
1095 	if (err)
1096 		goto free_node_manager_caches;
1097 	err = create_gc_caches();
1098 	if (err)
1099 		goto free_segment_manager_caches;
1100 	err = create_checkpoint_caches();
1101 	if (err)
1102 		goto free_gc_caches;
1103 	f2fs_kset = kset_create_and_add("f2fs", NULL, fs_kobj);
1104 	if (!f2fs_kset) {
1105 		err = -ENOMEM;
1106 		goto free_checkpoint_caches;
1107 	}
1108 	err = register_filesystem(&f2fs_fs_type);
1109 	if (err)
1110 		goto free_kset;
1111 	f2fs_create_root_stats();
1112 	f2fs_proc_root = proc_mkdir("fs/f2fs", NULL);
1113 	return 0;
1114 
1115 free_kset:
1116 	kset_unregister(f2fs_kset);
1117 free_checkpoint_caches:
1118 	destroy_checkpoint_caches();
1119 free_gc_caches:
1120 	destroy_gc_caches();
1121 free_segment_manager_caches:
1122 	destroy_segment_manager_caches();
1123 free_node_manager_caches:
1124 	destroy_node_manager_caches();
1125 free_inodecache:
1126 	destroy_inodecache();
1127 fail:
1128 	return err;
1129 }
1130 
1131 static void __exit exit_f2fs_fs(void)
1132 {
1133 	remove_proc_entry("fs/f2fs", NULL);
1134 	f2fs_destroy_root_stats();
1135 	unregister_filesystem(&f2fs_fs_type);
1136 	destroy_checkpoint_caches();
1137 	destroy_gc_caches();
1138 	destroy_node_manager_caches();
1139 	destroy_inodecache();
1140 	kset_unregister(f2fs_kset);
1141 }
1142 
1143 module_init(init_f2fs_fs)
1144 module_exit(exit_f2fs_fs)
1145 
1146 MODULE_AUTHOR("Samsung Electronics's Praesto Team");
1147 MODULE_DESCRIPTION("Flash Friendly File System");
1148 MODULE_LICENSE("GPL");
1149