xref: /linux/fs/f2fs/super.c (revision 071bf69a0220253a44acb8b2a27f7a262b9a46bf)
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 #include "trace.h"
34 
35 #define CREATE_TRACE_POINTS
36 #include <trace/events/f2fs.h>
37 
38 static struct proc_dir_entry *f2fs_proc_root;
39 static struct kmem_cache *f2fs_inode_cachep;
40 static struct kset *f2fs_kset;
41 
42 #ifdef CONFIG_F2FS_FAULT_INJECTION
43 struct f2fs_fault_info f2fs_fault;
44 
45 char *fault_name[FAULT_MAX] = {
46 	[FAULT_KMALLOC]		= "kmalloc",
47 	[FAULT_PAGE_ALLOC]	= "page alloc",
48 	[FAULT_ALLOC_NID]	= "alloc nid",
49 	[FAULT_ORPHAN]		= "orphan",
50 	[FAULT_BLOCK]		= "no more block",
51 	[FAULT_DIR_DEPTH]	= "too big dir depth",
52 	[FAULT_EVICT_INODE]	= "evict_inode fail",
53 };
54 
55 static void f2fs_build_fault_attr(unsigned int rate)
56 {
57 	if (rate) {
58 		atomic_set(&f2fs_fault.inject_ops, 0);
59 		f2fs_fault.inject_rate = rate;
60 		f2fs_fault.inject_type = (1 << FAULT_MAX) - 1;
61 	} else {
62 		memset(&f2fs_fault, 0, sizeof(struct f2fs_fault_info));
63 	}
64 }
65 #endif
66 
67 /* f2fs-wide shrinker description */
68 static struct shrinker f2fs_shrinker_info = {
69 	.scan_objects = f2fs_shrink_scan,
70 	.count_objects = f2fs_shrink_count,
71 	.seeks = DEFAULT_SEEKS,
72 };
73 
74 enum {
75 	Opt_gc_background,
76 	Opt_disable_roll_forward,
77 	Opt_norecovery,
78 	Opt_discard,
79 	Opt_nodiscard,
80 	Opt_noheap,
81 	Opt_user_xattr,
82 	Opt_nouser_xattr,
83 	Opt_acl,
84 	Opt_noacl,
85 	Opt_active_logs,
86 	Opt_disable_ext_identify,
87 	Opt_inline_xattr,
88 	Opt_inline_data,
89 	Opt_inline_dentry,
90 	Opt_flush_merge,
91 	Opt_noflush_merge,
92 	Opt_nobarrier,
93 	Opt_fastboot,
94 	Opt_extent_cache,
95 	Opt_noextent_cache,
96 	Opt_noinline_data,
97 	Opt_data_flush,
98 	Opt_mode,
99 	Opt_fault_injection,
100 	Opt_lazytime,
101 	Opt_nolazytime,
102 	Opt_err,
103 };
104 
105 static match_table_t f2fs_tokens = {
106 	{Opt_gc_background, "background_gc=%s"},
107 	{Opt_disable_roll_forward, "disable_roll_forward"},
108 	{Opt_norecovery, "norecovery"},
109 	{Opt_discard, "discard"},
110 	{Opt_nodiscard, "nodiscard"},
111 	{Opt_noheap, "no_heap"},
112 	{Opt_user_xattr, "user_xattr"},
113 	{Opt_nouser_xattr, "nouser_xattr"},
114 	{Opt_acl, "acl"},
115 	{Opt_noacl, "noacl"},
116 	{Opt_active_logs, "active_logs=%u"},
117 	{Opt_disable_ext_identify, "disable_ext_identify"},
118 	{Opt_inline_xattr, "inline_xattr"},
119 	{Opt_inline_data, "inline_data"},
120 	{Opt_inline_dentry, "inline_dentry"},
121 	{Opt_flush_merge, "flush_merge"},
122 	{Opt_noflush_merge, "noflush_merge"},
123 	{Opt_nobarrier, "nobarrier"},
124 	{Opt_fastboot, "fastboot"},
125 	{Opt_extent_cache, "extent_cache"},
126 	{Opt_noextent_cache, "noextent_cache"},
127 	{Opt_noinline_data, "noinline_data"},
128 	{Opt_data_flush, "data_flush"},
129 	{Opt_mode, "mode=%s"},
130 	{Opt_fault_injection, "fault_injection=%u"},
131 	{Opt_lazytime, "lazytime"},
132 	{Opt_nolazytime, "nolazytime"},
133 	{Opt_err, NULL},
134 };
135 
136 /* Sysfs support for f2fs */
137 enum {
138 	GC_THREAD,	/* struct f2fs_gc_thread */
139 	SM_INFO,	/* struct f2fs_sm_info */
140 	NM_INFO,	/* struct f2fs_nm_info */
141 	F2FS_SBI,	/* struct f2fs_sb_info */
142 #ifdef CONFIG_F2FS_FAULT_INJECTION
143 	FAULT_INFO_RATE,	/* struct f2fs_fault_info */
144 	FAULT_INFO_TYPE,	/* struct f2fs_fault_info */
145 #endif
146 };
147 
148 struct f2fs_attr {
149 	struct attribute attr;
150 	ssize_t (*show)(struct f2fs_attr *, struct f2fs_sb_info *, char *);
151 	ssize_t (*store)(struct f2fs_attr *, struct f2fs_sb_info *,
152 			 const char *, size_t);
153 	int struct_type;
154 	int offset;
155 };
156 
157 static unsigned char *__struct_ptr(struct f2fs_sb_info *sbi, int struct_type)
158 {
159 	if (struct_type == GC_THREAD)
160 		return (unsigned char *)sbi->gc_thread;
161 	else if (struct_type == SM_INFO)
162 		return (unsigned char *)SM_I(sbi);
163 	else if (struct_type == NM_INFO)
164 		return (unsigned char *)NM_I(sbi);
165 	else if (struct_type == F2FS_SBI)
166 		return (unsigned char *)sbi;
167 #ifdef CONFIG_F2FS_FAULT_INJECTION
168 	else if (struct_type == FAULT_INFO_RATE ||
169 					struct_type == FAULT_INFO_TYPE)
170 		return (unsigned char *)&f2fs_fault;
171 #endif
172 	return NULL;
173 }
174 
175 static ssize_t lifetime_write_kbytes_show(struct f2fs_attr *a,
176 		struct f2fs_sb_info *sbi, char *buf)
177 {
178 	struct super_block *sb = sbi->sb;
179 
180 	if (!sb->s_bdev->bd_part)
181 		return snprintf(buf, PAGE_SIZE, "0\n");
182 
183 	return snprintf(buf, PAGE_SIZE, "%llu\n",
184 		(unsigned long long)(sbi->kbytes_written +
185 			BD_PART_WRITTEN(sbi)));
186 }
187 
188 static ssize_t f2fs_sbi_show(struct f2fs_attr *a,
189 			struct f2fs_sb_info *sbi, char *buf)
190 {
191 	unsigned char *ptr = NULL;
192 	unsigned int *ui;
193 
194 	ptr = __struct_ptr(sbi, a->struct_type);
195 	if (!ptr)
196 		return -EINVAL;
197 
198 	ui = (unsigned int *)(ptr + a->offset);
199 
200 	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
201 }
202 
203 static ssize_t f2fs_sbi_store(struct f2fs_attr *a,
204 			struct f2fs_sb_info *sbi,
205 			const char *buf, size_t count)
206 {
207 	unsigned char *ptr;
208 	unsigned long t;
209 	unsigned int *ui;
210 	ssize_t ret;
211 
212 	ptr = __struct_ptr(sbi, a->struct_type);
213 	if (!ptr)
214 		return -EINVAL;
215 
216 	ui = (unsigned int *)(ptr + a->offset);
217 
218 	ret = kstrtoul(skip_spaces(buf), 0, &t);
219 	if (ret < 0)
220 		return ret;
221 #ifdef CONFIG_F2FS_FAULT_INJECTION
222 	if (a->struct_type == FAULT_INFO_TYPE && t >= (1 << FAULT_MAX))
223 		return -EINVAL;
224 #endif
225 	*ui = t;
226 	return count;
227 }
228 
229 static ssize_t f2fs_attr_show(struct kobject *kobj,
230 				struct attribute *attr, char *buf)
231 {
232 	struct f2fs_sb_info *sbi = container_of(kobj, struct f2fs_sb_info,
233 								s_kobj);
234 	struct f2fs_attr *a = container_of(attr, struct f2fs_attr, attr);
235 
236 	return a->show ? a->show(a, sbi, buf) : 0;
237 }
238 
239 static ssize_t f2fs_attr_store(struct kobject *kobj, struct attribute *attr,
240 						const char *buf, size_t len)
241 {
242 	struct f2fs_sb_info *sbi = container_of(kobj, struct f2fs_sb_info,
243 									s_kobj);
244 	struct f2fs_attr *a = container_of(attr, struct f2fs_attr, attr);
245 
246 	return a->store ? a->store(a, sbi, buf, len) : 0;
247 }
248 
249 static void f2fs_sb_release(struct kobject *kobj)
250 {
251 	struct f2fs_sb_info *sbi = container_of(kobj, struct f2fs_sb_info,
252 								s_kobj);
253 	complete(&sbi->s_kobj_unregister);
254 }
255 
256 #define F2FS_ATTR_OFFSET(_struct_type, _name, _mode, _show, _store, _offset) \
257 static struct f2fs_attr f2fs_attr_##_name = {			\
258 	.attr = {.name = __stringify(_name), .mode = _mode },	\
259 	.show	= _show,					\
260 	.store	= _store,					\
261 	.struct_type = _struct_type,				\
262 	.offset = _offset					\
263 }
264 
265 #define F2FS_RW_ATTR(struct_type, struct_name, name, elname)	\
266 	F2FS_ATTR_OFFSET(struct_type, name, 0644,		\
267 		f2fs_sbi_show, f2fs_sbi_store,			\
268 		offsetof(struct struct_name, elname))
269 
270 #define F2FS_GENERAL_RO_ATTR(name) \
271 static struct f2fs_attr f2fs_attr_##name = __ATTR(name, 0444, name##_show, NULL)
272 
273 F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_min_sleep_time, min_sleep_time);
274 F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_max_sleep_time, max_sleep_time);
275 F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_no_gc_sleep_time, no_gc_sleep_time);
276 F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_idle, gc_idle);
277 F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, reclaim_segments, rec_prefree_segments);
278 F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, max_small_discards, max_discards);
279 F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, batched_trim_sections, trim_sections);
280 F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, ipu_policy, ipu_policy);
281 F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_ipu_util, min_ipu_util);
282 F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_fsync_blocks, min_fsync_blocks);
283 F2FS_RW_ATTR(NM_INFO, f2fs_nm_info, ram_thresh, ram_thresh);
284 F2FS_RW_ATTR(NM_INFO, f2fs_nm_info, ra_nid_pages, ra_nid_pages);
285 F2FS_RW_ATTR(NM_INFO, f2fs_nm_info, dirty_nats_ratio, dirty_nats_ratio);
286 F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, max_victim_search, max_victim_search);
287 F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, dir_level, dir_level);
288 F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, cp_interval, interval_time[CP_TIME]);
289 F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, idle_interval, interval_time[REQ_TIME]);
290 #ifdef CONFIG_F2FS_FAULT_INJECTION
291 F2FS_RW_ATTR(FAULT_INFO_RATE, f2fs_fault_info, inject_rate, inject_rate);
292 F2FS_RW_ATTR(FAULT_INFO_TYPE, f2fs_fault_info, inject_type, inject_type);
293 #endif
294 F2FS_GENERAL_RO_ATTR(lifetime_write_kbytes);
295 
296 #define ATTR_LIST(name) (&f2fs_attr_##name.attr)
297 static struct attribute *f2fs_attrs[] = {
298 	ATTR_LIST(gc_min_sleep_time),
299 	ATTR_LIST(gc_max_sleep_time),
300 	ATTR_LIST(gc_no_gc_sleep_time),
301 	ATTR_LIST(gc_idle),
302 	ATTR_LIST(reclaim_segments),
303 	ATTR_LIST(max_small_discards),
304 	ATTR_LIST(batched_trim_sections),
305 	ATTR_LIST(ipu_policy),
306 	ATTR_LIST(min_ipu_util),
307 	ATTR_LIST(min_fsync_blocks),
308 	ATTR_LIST(max_victim_search),
309 	ATTR_LIST(dir_level),
310 	ATTR_LIST(ram_thresh),
311 	ATTR_LIST(ra_nid_pages),
312 	ATTR_LIST(dirty_nats_ratio),
313 	ATTR_LIST(cp_interval),
314 	ATTR_LIST(idle_interval),
315 	ATTR_LIST(lifetime_write_kbytes),
316 	NULL,
317 };
318 
319 static const struct sysfs_ops f2fs_attr_ops = {
320 	.show	= f2fs_attr_show,
321 	.store	= f2fs_attr_store,
322 };
323 
324 static struct kobj_type f2fs_ktype = {
325 	.default_attrs	= f2fs_attrs,
326 	.sysfs_ops	= &f2fs_attr_ops,
327 	.release	= f2fs_sb_release,
328 };
329 
330 #ifdef CONFIG_F2FS_FAULT_INJECTION
331 /* sysfs for f2fs fault injection */
332 static struct kobject f2fs_fault_inject;
333 
334 static struct attribute *f2fs_fault_attrs[] = {
335 	ATTR_LIST(inject_rate),
336 	ATTR_LIST(inject_type),
337 	NULL
338 };
339 
340 static struct kobj_type f2fs_fault_ktype = {
341 	.default_attrs	= f2fs_fault_attrs,
342 	.sysfs_ops	= &f2fs_attr_ops,
343 };
344 #endif
345 
346 void f2fs_msg(struct super_block *sb, const char *level, const char *fmt, ...)
347 {
348 	struct va_format vaf;
349 	va_list args;
350 
351 	va_start(args, fmt);
352 	vaf.fmt = fmt;
353 	vaf.va = &args;
354 	printk("%sF2FS-fs (%s): %pV\n", level, sb->s_id, &vaf);
355 	va_end(args);
356 }
357 
358 static void init_once(void *foo)
359 {
360 	struct f2fs_inode_info *fi = (struct f2fs_inode_info *) foo;
361 
362 	inode_init_once(&fi->vfs_inode);
363 }
364 
365 static int parse_options(struct super_block *sb, char *options)
366 {
367 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
368 	struct request_queue *q;
369 	substring_t args[MAX_OPT_ARGS];
370 	char *p, *name;
371 	int arg = 0;
372 
373 #ifdef CONFIG_F2FS_FAULT_INJECTION
374 	f2fs_build_fault_attr(0);
375 #endif
376 
377 	if (!options)
378 		return 0;
379 
380 	while ((p = strsep(&options, ",")) != NULL) {
381 		int token;
382 		if (!*p)
383 			continue;
384 		/*
385 		 * Initialize args struct so we know whether arg was
386 		 * found; some options take optional arguments.
387 		 */
388 		args[0].to = args[0].from = NULL;
389 		token = match_token(p, f2fs_tokens, args);
390 
391 		switch (token) {
392 		case Opt_gc_background:
393 			name = match_strdup(&args[0]);
394 
395 			if (!name)
396 				return -ENOMEM;
397 			if (strlen(name) == 2 && !strncmp(name, "on", 2)) {
398 				set_opt(sbi, BG_GC);
399 				clear_opt(sbi, FORCE_FG_GC);
400 			} else if (strlen(name) == 3 && !strncmp(name, "off", 3)) {
401 				clear_opt(sbi, BG_GC);
402 				clear_opt(sbi, FORCE_FG_GC);
403 			} else if (strlen(name) == 4 && !strncmp(name, "sync", 4)) {
404 				set_opt(sbi, BG_GC);
405 				set_opt(sbi, FORCE_FG_GC);
406 			} else {
407 				kfree(name);
408 				return -EINVAL;
409 			}
410 			kfree(name);
411 			break;
412 		case Opt_disable_roll_forward:
413 			set_opt(sbi, DISABLE_ROLL_FORWARD);
414 			break;
415 		case Opt_norecovery:
416 			/* this option mounts f2fs with ro */
417 			set_opt(sbi, DISABLE_ROLL_FORWARD);
418 			if (!f2fs_readonly(sb))
419 				return -EINVAL;
420 			break;
421 		case Opt_discard:
422 			q = bdev_get_queue(sb->s_bdev);
423 			if (blk_queue_discard(q)) {
424 				set_opt(sbi, DISCARD);
425 			} else {
426 				f2fs_msg(sb, KERN_WARNING,
427 					"mounting with \"discard\" option, but "
428 					"the device does not support discard");
429 			}
430 			break;
431 		case Opt_nodiscard:
432 			clear_opt(sbi, DISCARD);
433 		case Opt_noheap:
434 			set_opt(sbi, NOHEAP);
435 			break;
436 #ifdef CONFIG_F2FS_FS_XATTR
437 		case Opt_user_xattr:
438 			set_opt(sbi, XATTR_USER);
439 			break;
440 		case Opt_nouser_xattr:
441 			clear_opt(sbi, XATTR_USER);
442 			break;
443 		case Opt_inline_xattr:
444 			set_opt(sbi, INLINE_XATTR);
445 			break;
446 #else
447 		case Opt_user_xattr:
448 			f2fs_msg(sb, KERN_INFO,
449 				"user_xattr options not supported");
450 			break;
451 		case Opt_nouser_xattr:
452 			f2fs_msg(sb, KERN_INFO,
453 				"nouser_xattr options not supported");
454 			break;
455 		case Opt_inline_xattr:
456 			f2fs_msg(sb, KERN_INFO,
457 				"inline_xattr options not supported");
458 			break;
459 #endif
460 #ifdef CONFIG_F2FS_FS_POSIX_ACL
461 		case Opt_acl:
462 			set_opt(sbi, POSIX_ACL);
463 			break;
464 		case Opt_noacl:
465 			clear_opt(sbi, POSIX_ACL);
466 			break;
467 #else
468 		case Opt_acl:
469 			f2fs_msg(sb, KERN_INFO, "acl options not supported");
470 			break;
471 		case Opt_noacl:
472 			f2fs_msg(sb, KERN_INFO, "noacl options not supported");
473 			break;
474 #endif
475 		case Opt_active_logs:
476 			if (args->from && match_int(args, &arg))
477 				return -EINVAL;
478 			if (arg != 2 && arg != 4 && arg != NR_CURSEG_TYPE)
479 				return -EINVAL;
480 			sbi->active_logs = arg;
481 			break;
482 		case Opt_disable_ext_identify:
483 			set_opt(sbi, DISABLE_EXT_IDENTIFY);
484 			break;
485 		case Opt_inline_data:
486 			set_opt(sbi, INLINE_DATA);
487 			break;
488 		case Opt_inline_dentry:
489 			set_opt(sbi, INLINE_DENTRY);
490 			break;
491 		case Opt_flush_merge:
492 			set_opt(sbi, FLUSH_MERGE);
493 			break;
494 		case Opt_noflush_merge:
495 			clear_opt(sbi, FLUSH_MERGE);
496 			break;
497 		case Opt_nobarrier:
498 			set_opt(sbi, NOBARRIER);
499 			break;
500 		case Opt_fastboot:
501 			set_opt(sbi, FASTBOOT);
502 			break;
503 		case Opt_extent_cache:
504 			set_opt(sbi, EXTENT_CACHE);
505 			break;
506 		case Opt_noextent_cache:
507 			clear_opt(sbi, EXTENT_CACHE);
508 			break;
509 		case Opt_noinline_data:
510 			clear_opt(sbi, INLINE_DATA);
511 			break;
512 		case Opt_data_flush:
513 			set_opt(sbi, DATA_FLUSH);
514 			break;
515 		case Opt_mode:
516 			name = match_strdup(&args[0]);
517 
518 			if (!name)
519 				return -ENOMEM;
520 			if (strlen(name) == 8 &&
521 					!strncmp(name, "adaptive", 8)) {
522 				set_opt_mode(sbi, F2FS_MOUNT_ADAPTIVE);
523 			} else if (strlen(name) == 3 &&
524 					!strncmp(name, "lfs", 3)) {
525 				set_opt_mode(sbi, F2FS_MOUNT_LFS);
526 			} else {
527 				kfree(name);
528 				return -EINVAL;
529 			}
530 			kfree(name);
531 			break;
532 		case Opt_fault_injection:
533 			if (args->from && match_int(args, &arg))
534 				return -EINVAL;
535 #ifdef CONFIG_F2FS_FAULT_INJECTION
536 			f2fs_build_fault_attr(arg);
537 #else
538 			f2fs_msg(sb, KERN_INFO,
539 				"FAULT_INJECTION was not selected");
540 #endif
541 			break;
542 		case Opt_lazytime:
543 			sb->s_flags |= MS_LAZYTIME;
544 			break;
545 		case Opt_nolazytime:
546 			sb->s_flags &= ~MS_LAZYTIME;
547 			break;
548 		default:
549 			f2fs_msg(sb, KERN_ERR,
550 				"Unrecognized mount option \"%s\" or missing value",
551 				p);
552 			return -EINVAL;
553 		}
554 	}
555 	return 0;
556 }
557 
558 static struct inode *f2fs_alloc_inode(struct super_block *sb)
559 {
560 	struct f2fs_inode_info *fi;
561 
562 	fi = kmem_cache_alloc(f2fs_inode_cachep, GFP_F2FS_ZERO);
563 	if (!fi)
564 		return NULL;
565 
566 	init_once((void *) fi);
567 
568 	if (percpu_counter_init(&fi->dirty_pages, 0, GFP_NOFS)) {
569 		kmem_cache_free(f2fs_inode_cachep, fi);
570 		return NULL;
571 	}
572 
573 	/* Initialize f2fs-specific inode info */
574 	fi->vfs_inode.i_version = 1;
575 	fi->i_current_depth = 1;
576 	fi->i_advise = 0;
577 	init_rwsem(&fi->i_sem);
578 	INIT_LIST_HEAD(&fi->dirty_list);
579 	INIT_LIST_HEAD(&fi->gdirty_list);
580 	INIT_LIST_HEAD(&fi->inmem_pages);
581 	mutex_init(&fi->inmem_lock);
582 	init_rwsem(&fi->dio_rwsem[READ]);
583 	init_rwsem(&fi->dio_rwsem[WRITE]);
584 
585 	/* Will be used by directory only */
586 	fi->i_dir_level = F2FS_SB(sb)->dir_level;
587 	return &fi->vfs_inode;
588 }
589 
590 static int f2fs_drop_inode(struct inode *inode)
591 {
592 	/*
593 	 * This is to avoid a deadlock condition like below.
594 	 * writeback_single_inode(inode)
595 	 *  - f2fs_write_data_page
596 	 *    - f2fs_gc -> iput -> evict
597 	 *       - inode_wait_for_writeback(inode)
598 	 */
599 	if ((!inode_unhashed(inode) && inode->i_state & I_SYNC)) {
600 		if (!inode->i_nlink && !is_bad_inode(inode)) {
601 			/* to avoid evict_inode call simultaneously */
602 			atomic_inc(&inode->i_count);
603 			spin_unlock(&inode->i_lock);
604 
605 			/* some remained atomic pages should discarded */
606 			if (f2fs_is_atomic_file(inode))
607 				drop_inmem_pages(inode);
608 
609 			/* should remain fi->extent_tree for writepage */
610 			f2fs_destroy_extent_node(inode);
611 
612 			sb_start_intwrite(inode->i_sb);
613 			f2fs_i_size_write(inode, 0);
614 
615 			if (F2FS_HAS_BLOCKS(inode))
616 				f2fs_truncate(inode);
617 
618 			sb_end_intwrite(inode->i_sb);
619 
620 			fscrypt_put_encryption_info(inode, NULL);
621 			spin_lock(&inode->i_lock);
622 			atomic_dec(&inode->i_count);
623 		}
624 		return 0;
625 	}
626 
627 	return generic_drop_inode(inode);
628 }
629 
630 int f2fs_inode_dirtied(struct inode *inode)
631 {
632 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
633 
634 	spin_lock(&sbi->inode_lock[DIRTY_META]);
635 	if (is_inode_flag_set(inode, FI_DIRTY_INODE)) {
636 		spin_unlock(&sbi->inode_lock[DIRTY_META]);
637 		return 1;
638 	}
639 
640 	set_inode_flag(inode, FI_DIRTY_INODE);
641 	list_add_tail(&F2FS_I(inode)->gdirty_list,
642 				&sbi->inode_list[DIRTY_META]);
643 	inc_page_count(sbi, F2FS_DIRTY_IMETA);
644 	stat_inc_dirty_inode(sbi, DIRTY_META);
645 	spin_unlock(&sbi->inode_lock[DIRTY_META]);
646 
647 	return 0;
648 }
649 
650 void f2fs_inode_synced(struct inode *inode)
651 {
652 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
653 
654 	spin_lock(&sbi->inode_lock[DIRTY_META]);
655 	if (!is_inode_flag_set(inode, FI_DIRTY_INODE)) {
656 		spin_unlock(&sbi->inode_lock[DIRTY_META]);
657 		return;
658 	}
659 	list_del_init(&F2FS_I(inode)->gdirty_list);
660 	clear_inode_flag(inode, FI_DIRTY_INODE);
661 	clear_inode_flag(inode, FI_AUTO_RECOVER);
662 	dec_page_count(sbi, F2FS_DIRTY_IMETA);
663 	stat_dec_dirty_inode(F2FS_I_SB(inode), DIRTY_META);
664 	spin_unlock(&sbi->inode_lock[DIRTY_META]);
665 }
666 
667 /*
668  * f2fs_dirty_inode() is called from __mark_inode_dirty()
669  *
670  * We should call set_dirty_inode to write the dirty inode through write_inode.
671  */
672 static void f2fs_dirty_inode(struct inode *inode, int flags)
673 {
674 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
675 
676 	if (inode->i_ino == F2FS_NODE_INO(sbi) ||
677 			inode->i_ino == F2FS_META_INO(sbi))
678 		return;
679 
680 	if (flags == I_DIRTY_TIME)
681 		return;
682 
683 	if (is_inode_flag_set(inode, FI_AUTO_RECOVER))
684 		clear_inode_flag(inode, FI_AUTO_RECOVER);
685 
686 	f2fs_inode_dirtied(inode);
687 }
688 
689 static void f2fs_i_callback(struct rcu_head *head)
690 {
691 	struct inode *inode = container_of(head, struct inode, i_rcu);
692 	kmem_cache_free(f2fs_inode_cachep, F2FS_I(inode));
693 }
694 
695 static void f2fs_destroy_inode(struct inode *inode)
696 {
697 	percpu_counter_destroy(&F2FS_I(inode)->dirty_pages);
698 	call_rcu(&inode->i_rcu, f2fs_i_callback);
699 }
700 
701 static void destroy_percpu_info(struct f2fs_sb_info *sbi)
702 {
703 	int i;
704 
705 	for (i = 0; i < NR_COUNT_TYPE; i++)
706 		percpu_counter_destroy(&sbi->nr_pages[i]);
707 	percpu_counter_destroy(&sbi->alloc_valid_block_count);
708 	percpu_counter_destroy(&sbi->total_valid_inode_count);
709 
710 	percpu_free_rwsem(&sbi->cp_rwsem);
711 }
712 
713 static void f2fs_put_super(struct super_block *sb)
714 {
715 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
716 
717 	if (sbi->s_proc) {
718 		remove_proc_entry("segment_info", sbi->s_proc);
719 		remove_proc_entry("segment_bits", sbi->s_proc);
720 		remove_proc_entry(sb->s_id, f2fs_proc_root);
721 	}
722 	kobject_del(&sbi->s_kobj);
723 
724 	stop_gc_thread(sbi);
725 
726 	/* prevent remaining shrinker jobs */
727 	mutex_lock(&sbi->umount_mutex);
728 
729 	/*
730 	 * We don't need to do checkpoint when superblock is clean.
731 	 * But, the previous checkpoint was not done by umount, it needs to do
732 	 * clean checkpoint again.
733 	 */
734 	if (is_sbi_flag_set(sbi, SBI_IS_DIRTY) ||
735 			!is_set_ckpt_flags(F2FS_CKPT(sbi), CP_UMOUNT_FLAG)) {
736 		struct cp_control cpc = {
737 			.reason = CP_UMOUNT,
738 		};
739 		write_checkpoint(sbi, &cpc);
740 	}
741 
742 	/* write_checkpoint can update stat informaion */
743 	f2fs_destroy_stats(sbi);
744 
745 	/*
746 	 * normally superblock is clean, so we need to release this.
747 	 * In addition, EIO will skip do checkpoint, we need this as well.
748 	 */
749 	release_ino_entry(sbi, true);
750 	release_discard_addrs(sbi);
751 
752 	f2fs_leave_shrinker(sbi);
753 	mutex_unlock(&sbi->umount_mutex);
754 
755 	/* our cp_error case, we can wait for any writeback page */
756 	f2fs_flush_merged_bios(sbi);
757 
758 	iput(sbi->node_inode);
759 	iput(sbi->meta_inode);
760 
761 	/* destroy f2fs internal modules */
762 	destroy_node_manager(sbi);
763 	destroy_segment_manager(sbi);
764 
765 	kfree(sbi->ckpt);
766 	kobject_put(&sbi->s_kobj);
767 	wait_for_completion(&sbi->s_kobj_unregister);
768 
769 	sb->s_fs_info = NULL;
770 	if (sbi->s_chksum_driver)
771 		crypto_free_shash(sbi->s_chksum_driver);
772 	kfree(sbi->raw_super);
773 
774 	destroy_percpu_info(sbi);
775 	kfree(sbi);
776 }
777 
778 int f2fs_sync_fs(struct super_block *sb, int sync)
779 {
780 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
781 	int err = 0;
782 
783 	trace_f2fs_sync_fs(sb, sync);
784 
785 	if (sync) {
786 		struct cp_control cpc;
787 
788 		cpc.reason = __get_cp_reason(sbi);
789 
790 		mutex_lock(&sbi->gc_mutex);
791 		err = write_checkpoint(sbi, &cpc);
792 		mutex_unlock(&sbi->gc_mutex);
793 	}
794 	f2fs_trace_ios(NULL, 1);
795 
796 	return err;
797 }
798 
799 static int f2fs_freeze(struct super_block *sb)
800 {
801 	int err;
802 
803 	if (f2fs_readonly(sb))
804 		return 0;
805 
806 	err = f2fs_sync_fs(sb, 1);
807 	return err;
808 }
809 
810 static int f2fs_unfreeze(struct super_block *sb)
811 {
812 	return 0;
813 }
814 
815 static int f2fs_statfs(struct dentry *dentry, struct kstatfs *buf)
816 {
817 	struct super_block *sb = dentry->d_sb;
818 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
819 	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
820 	block_t total_count, user_block_count, start_count, ovp_count;
821 
822 	total_count = le64_to_cpu(sbi->raw_super->block_count);
823 	user_block_count = sbi->user_block_count;
824 	start_count = le32_to_cpu(sbi->raw_super->segment0_blkaddr);
825 	ovp_count = SM_I(sbi)->ovp_segments << sbi->log_blocks_per_seg;
826 	buf->f_type = F2FS_SUPER_MAGIC;
827 	buf->f_bsize = sbi->blocksize;
828 
829 	buf->f_blocks = total_count - start_count;
830 	buf->f_bfree = user_block_count - valid_user_blocks(sbi) + ovp_count;
831 	buf->f_bavail = user_block_count - valid_user_blocks(sbi);
832 
833 	buf->f_files = sbi->total_node_count - F2FS_RESERVED_NODE_NUM;
834 	buf->f_ffree = buf->f_files - valid_inode_count(sbi);
835 
836 	buf->f_namelen = F2FS_NAME_LEN;
837 	buf->f_fsid.val[0] = (u32)id;
838 	buf->f_fsid.val[1] = (u32)(id >> 32);
839 
840 	return 0;
841 }
842 
843 static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
844 {
845 	struct f2fs_sb_info *sbi = F2FS_SB(root->d_sb);
846 
847 	if (!f2fs_readonly(sbi->sb) && test_opt(sbi, BG_GC)) {
848 		if (test_opt(sbi, FORCE_FG_GC))
849 			seq_printf(seq, ",background_gc=%s", "sync");
850 		else
851 			seq_printf(seq, ",background_gc=%s", "on");
852 	} else {
853 		seq_printf(seq, ",background_gc=%s", "off");
854 	}
855 	if (test_opt(sbi, DISABLE_ROLL_FORWARD))
856 		seq_puts(seq, ",disable_roll_forward");
857 	if (test_opt(sbi, DISCARD))
858 		seq_puts(seq, ",discard");
859 	if (test_opt(sbi, NOHEAP))
860 		seq_puts(seq, ",no_heap_alloc");
861 #ifdef CONFIG_F2FS_FS_XATTR
862 	if (test_opt(sbi, XATTR_USER))
863 		seq_puts(seq, ",user_xattr");
864 	else
865 		seq_puts(seq, ",nouser_xattr");
866 	if (test_opt(sbi, INLINE_XATTR))
867 		seq_puts(seq, ",inline_xattr");
868 #endif
869 #ifdef CONFIG_F2FS_FS_POSIX_ACL
870 	if (test_opt(sbi, POSIX_ACL))
871 		seq_puts(seq, ",acl");
872 	else
873 		seq_puts(seq, ",noacl");
874 #endif
875 	if (test_opt(sbi, DISABLE_EXT_IDENTIFY))
876 		seq_puts(seq, ",disable_ext_identify");
877 	if (test_opt(sbi, INLINE_DATA))
878 		seq_puts(seq, ",inline_data");
879 	else
880 		seq_puts(seq, ",noinline_data");
881 	if (test_opt(sbi, INLINE_DENTRY))
882 		seq_puts(seq, ",inline_dentry");
883 	if (!f2fs_readonly(sbi->sb) && test_opt(sbi, FLUSH_MERGE))
884 		seq_puts(seq, ",flush_merge");
885 	if (test_opt(sbi, NOBARRIER))
886 		seq_puts(seq, ",nobarrier");
887 	if (test_opt(sbi, FASTBOOT))
888 		seq_puts(seq, ",fastboot");
889 	if (test_opt(sbi, EXTENT_CACHE))
890 		seq_puts(seq, ",extent_cache");
891 	else
892 		seq_puts(seq, ",noextent_cache");
893 	if (test_opt(sbi, DATA_FLUSH))
894 		seq_puts(seq, ",data_flush");
895 
896 	seq_puts(seq, ",mode=");
897 	if (test_opt(sbi, ADAPTIVE))
898 		seq_puts(seq, "adaptive");
899 	else if (test_opt(sbi, LFS))
900 		seq_puts(seq, "lfs");
901 	seq_printf(seq, ",active_logs=%u", sbi->active_logs);
902 
903 	return 0;
904 }
905 
906 static int segment_info_seq_show(struct seq_file *seq, void *offset)
907 {
908 	struct super_block *sb = seq->private;
909 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
910 	unsigned int total_segs =
911 			le32_to_cpu(sbi->raw_super->segment_count_main);
912 	int i;
913 
914 	seq_puts(seq, "format: segment_type|valid_blocks\n"
915 		"segment_type(0:HD, 1:WD, 2:CD, 3:HN, 4:WN, 5:CN)\n");
916 
917 	for (i = 0; i < total_segs; i++) {
918 		struct seg_entry *se = get_seg_entry(sbi, i);
919 
920 		if ((i % 10) == 0)
921 			seq_printf(seq, "%-10d", i);
922 		seq_printf(seq, "%d|%-3u", se->type,
923 					get_valid_blocks(sbi, i, 1));
924 		if ((i % 10) == 9 || i == (total_segs - 1))
925 			seq_putc(seq, '\n');
926 		else
927 			seq_putc(seq, ' ');
928 	}
929 
930 	return 0;
931 }
932 
933 static int segment_bits_seq_show(struct seq_file *seq, void *offset)
934 {
935 	struct super_block *sb = seq->private;
936 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
937 	unsigned int total_segs =
938 			le32_to_cpu(sbi->raw_super->segment_count_main);
939 	int i, j;
940 
941 	seq_puts(seq, "format: segment_type|valid_blocks|bitmaps\n"
942 		"segment_type(0:HD, 1:WD, 2:CD, 3:HN, 4:WN, 5:CN)\n");
943 
944 	for (i = 0; i < total_segs; i++) {
945 		struct seg_entry *se = get_seg_entry(sbi, i);
946 
947 		seq_printf(seq, "%-10d", i);
948 		seq_printf(seq, "%d|%-3u|", se->type,
949 					get_valid_blocks(sbi, i, 1));
950 		for (j = 0; j < SIT_VBLOCK_MAP_SIZE; j++)
951 			seq_printf(seq, "%x ", se->cur_valid_map[j]);
952 		seq_putc(seq, '\n');
953 	}
954 	return 0;
955 }
956 
957 #define F2FS_PROC_FILE_DEF(_name)					\
958 static int _name##_open_fs(struct inode *inode, struct file *file)	\
959 {									\
960 	return single_open(file, _name##_seq_show, PDE_DATA(inode));	\
961 }									\
962 									\
963 static const struct file_operations f2fs_seq_##_name##_fops = {		\
964 	.open = _name##_open_fs,					\
965 	.read = seq_read,						\
966 	.llseek = seq_lseek,						\
967 	.release = single_release,					\
968 };
969 
970 F2FS_PROC_FILE_DEF(segment_info);
971 F2FS_PROC_FILE_DEF(segment_bits);
972 
973 static void default_options(struct f2fs_sb_info *sbi)
974 {
975 	/* init some FS parameters */
976 	sbi->active_logs = NR_CURSEG_TYPE;
977 
978 	set_opt(sbi, BG_GC);
979 	set_opt(sbi, INLINE_DATA);
980 	set_opt(sbi, EXTENT_CACHE);
981 	sbi->sb->s_flags |= MS_LAZYTIME;
982 	set_opt(sbi, FLUSH_MERGE);
983 	if (f2fs_sb_mounted_hmsmr(sbi->sb)) {
984 		set_opt_mode(sbi, F2FS_MOUNT_LFS);
985 		set_opt(sbi, DISCARD);
986 	} else {
987 		set_opt_mode(sbi, F2FS_MOUNT_ADAPTIVE);
988 	}
989 
990 #ifdef CONFIG_F2FS_FS_XATTR
991 	set_opt(sbi, XATTR_USER);
992 #endif
993 #ifdef CONFIG_F2FS_FS_POSIX_ACL
994 	set_opt(sbi, POSIX_ACL);
995 #endif
996 }
997 
998 static int f2fs_remount(struct super_block *sb, int *flags, char *data)
999 {
1000 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
1001 	struct f2fs_mount_info org_mount_opt;
1002 	int err, active_logs;
1003 	bool need_restart_gc = false;
1004 	bool need_stop_gc = false;
1005 	bool no_extent_cache = !test_opt(sbi, EXTENT_CACHE);
1006 
1007 	/*
1008 	 * Save the old mount options in case we
1009 	 * need to restore them.
1010 	 */
1011 	org_mount_opt = sbi->mount_opt;
1012 	active_logs = sbi->active_logs;
1013 
1014 	/* recover superblocks we couldn't write due to previous RO mount */
1015 	if (!(*flags & MS_RDONLY) && is_sbi_flag_set(sbi, SBI_NEED_SB_WRITE)) {
1016 		err = f2fs_commit_super(sbi, false);
1017 		f2fs_msg(sb, KERN_INFO,
1018 			"Try to recover all the superblocks, ret: %d", err);
1019 		if (!err)
1020 			clear_sbi_flag(sbi, SBI_NEED_SB_WRITE);
1021 	}
1022 
1023 	sbi->mount_opt.opt = 0;
1024 	default_options(sbi);
1025 
1026 	/* parse mount options */
1027 	err = parse_options(sb, data);
1028 	if (err)
1029 		goto restore_opts;
1030 
1031 	/*
1032 	 * Previous and new state of filesystem is RO,
1033 	 * so skip checking GC and FLUSH_MERGE conditions.
1034 	 */
1035 	if (f2fs_readonly(sb) && (*flags & MS_RDONLY))
1036 		goto skip;
1037 
1038 	/* disallow enable/disable extent_cache dynamically */
1039 	if (no_extent_cache == !!test_opt(sbi, EXTENT_CACHE)) {
1040 		err = -EINVAL;
1041 		f2fs_msg(sbi->sb, KERN_WARNING,
1042 				"switch extent_cache option is not allowed");
1043 		goto restore_opts;
1044 	}
1045 
1046 	/*
1047 	 * We stop the GC thread if FS is mounted as RO
1048 	 * or if background_gc = off is passed in mount
1049 	 * option. Also sync the filesystem.
1050 	 */
1051 	if ((*flags & MS_RDONLY) || !test_opt(sbi, BG_GC)) {
1052 		if (sbi->gc_thread) {
1053 			stop_gc_thread(sbi);
1054 			need_restart_gc = true;
1055 		}
1056 	} else if (!sbi->gc_thread) {
1057 		err = start_gc_thread(sbi);
1058 		if (err)
1059 			goto restore_opts;
1060 		need_stop_gc = true;
1061 	}
1062 
1063 	if (*flags & MS_RDONLY) {
1064 		writeback_inodes_sb(sb, WB_REASON_SYNC);
1065 		sync_inodes_sb(sb);
1066 
1067 		set_sbi_flag(sbi, SBI_IS_DIRTY);
1068 		set_sbi_flag(sbi, SBI_IS_CLOSE);
1069 		f2fs_sync_fs(sb, 1);
1070 		clear_sbi_flag(sbi, SBI_IS_CLOSE);
1071 	}
1072 
1073 	/*
1074 	 * We stop issue flush thread if FS is mounted as RO
1075 	 * or if flush_merge is not passed in mount option.
1076 	 */
1077 	if ((*flags & MS_RDONLY) || !test_opt(sbi, FLUSH_MERGE)) {
1078 		destroy_flush_cmd_control(sbi);
1079 	} else if (!SM_I(sbi)->cmd_control_info) {
1080 		err = create_flush_cmd_control(sbi);
1081 		if (err)
1082 			goto restore_gc;
1083 	}
1084 skip:
1085 	/* Update the POSIXACL Flag */
1086 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1087 		(test_opt(sbi, POSIX_ACL) ? MS_POSIXACL : 0);
1088 
1089 	return 0;
1090 restore_gc:
1091 	if (need_restart_gc) {
1092 		if (start_gc_thread(sbi))
1093 			f2fs_msg(sbi->sb, KERN_WARNING,
1094 				"background gc thread has stopped");
1095 	} else if (need_stop_gc) {
1096 		stop_gc_thread(sbi);
1097 	}
1098 restore_opts:
1099 	sbi->mount_opt = org_mount_opt;
1100 	sbi->active_logs = active_logs;
1101 	return err;
1102 }
1103 
1104 static struct super_operations f2fs_sops = {
1105 	.alloc_inode	= f2fs_alloc_inode,
1106 	.drop_inode	= f2fs_drop_inode,
1107 	.destroy_inode	= f2fs_destroy_inode,
1108 	.write_inode	= f2fs_write_inode,
1109 	.dirty_inode	= f2fs_dirty_inode,
1110 	.show_options	= f2fs_show_options,
1111 	.evict_inode	= f2fs_evict_inode,
1112 	.put_super	= f2fs_put_super,
1113 	.sync_fs	= f2fs_sync_fs,
1114 	.freeze_fs	= f2fs_freeze,
1115 	.unfreeze_fs	= f2fs_unfreeze,
1116 	.statfs		= f2fs_statfs,
1117 	.remount_fs	= f2fs_remount,
1118 };
1119 
1120 #ifdef CONFIG_F2FS_FS_ENCRYPTION
1121 static int f2fs_get_context(struct inode *inode, void *ctx, size_t len)
1122 {
1123 	return f2fs_getxattr(inode, F2FS_XATTR_INDEX_ENCRYPTION,
1124 				F2FS_XATTR_NAME_ENCRYPTION_CONTEXT,
1125 				ctx, len, NULL);
1126 }
1127 
1128 static int f2fs_key_prefix(struct inode *inode, u8 **key)
1129 {
1130 	*key = F2FS_I_SB(inode)->key_prefix;
1131 	return F2FS_I_SB(inode)->key_prefix_size;
1132 }
1133 
1134 static int f2fs_set_context(struct inode *inode, const void *ctx, size_t len,
1135 							void *fs_data)
1136 {
1137 	return f2fs_setxattr(inode, F2FS_XATTR_INDEX_ENCRYPTION,
1138 				F2FS_XATTR_NAME_ENCRYPTION_CONTEXT,
1139 				ctx, len, fs_data, XATTR_CREATE);
1140 }
1141 
1142 static unsigned f2fs_max_namelen(struct inode *inode)
1143 {
1144 	return S_ISLNK(inode->i_mode) ?
1145 			inode->i_sb->s_blocksize : F2FS_NAME_LEN;
1146 }
1147 
1148 static struct fscrypt_operations f2fs_cryptops = {
1149 	.get_context	= f2fs_get_context,
1150 	.key_prefix	= f2fs_key_prefix,
1151 	.set_context	= f2fs_set_context,
1152 	.is_encrypted	= f2fs_encrypted_inode,
1153 	.empty_dir	= f2fs_empty_dir,
1154 	.max_namelen	= f2fs_max_namelen,
1155 };
1156 #else
1157 static struct fscrypt_operations f2fs_cryptops = {
1158 	.is_encrypted	= f2fs_encrypted_inode,
1159 };
1160 #endif
1161 
1162 static struct inode *f2fs_nfs_get_inode(struct super_block *sb,
1163 		u64 ino, u32 generation)
1164 {
1165 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
1166 	struct inode *inode;
1167 
1168 	if (check_nid_range(sbi, ino))
1169 		return ERR_PTR(-ESTALE);
1170 
1171 	/*
1172 	 * f2fs_iget isn't quite right if the inode is currently unallocated!
1173 	 * However f2fs_iget currently does appropriate checks to handle stale
1174 	 * inodes so everything is OK.
1175 	 */
1176 	inode = f2fs_iget(sb, ino);
1177 	if (IS_ERR(inode))
1178 		return ERR_CAST(inode);
1179 	if (unlikely(generation && inode->i_generation != generation)) {
1180 		/* we didn't find the right inode.. */
1181 		iput(inode);
1182 		return ERR_PTR(-ESTALE);
1183 	}
1184 	return inode;
1185 }
1186 
1187 static struct dentry *f2fs_fh_to_dentry(struct super_block *sb, struct fid *fid,
1188 		int fh_len, int fh_type)
1189 {
1190 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1191 				    f2fs_nfs_get_inode);
1192 }
1193 
1194 static struct dentry *f2fs_fh_to_parent(struct super_block *sb, struct fid *fid,
1195 		int fh_len, int fh_type)
1196 {
1197 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1198 				    f2fs_nfs_get_inode);
1199 }
1200 
1201 static const struct export_operations f2fs_export_ops = {
1202 	.fh_to_dentry = f2fs_fh_to_dentry,
1203 	.fh_to_parent = f2fs_fh_to_parent,
1204 	.get_parent = f2fs_get_parent,
1205 };
1206 
1207 static loff_t max_file_blocks(void)
1208 {
1209 	loff_t result = (DEF_ADDRS_PER_INODE - F2FS_INLINE_XATTR_ADDRS);
1210 	loff_t leaf_count = ADDRS_PER_BLOCK;
1211 
1212 	/* two direct node blocks */
1213 	result += (leaf_count * 2);
1214 
1215 	/* two indirect node blocks */
1216 	leaf_count *= NIDS_PER_BLOCK;
1217 	result += (leaf_count * 2);
1218 
1219 	/* one double indirect node block */
1220 	leaf_count *= NIDS_PER_BLOCK;
1221 	result += leaf_count;
1222 
1223 	return result;
1224 }
1225 
1226 static int __f2fs_commit_super(struct buffer_head *bh,
1227 			struct f2fs_super_block *super)
1228 {
1229 	lock_buffer(bh);
1230 	if (super)
1231 		memcpy(bh->b_data + F2FS_SUPER_OFFSET, super, sizeof(*super));
1232 	set_buffer_uptodate(bh);
1233 	set_buffer_dirty(bh);
1234 	unlock_buffer(bh);
1235 
1236 	/* it's rare case, we can do fua all the time */
1237 	return __sync_dirty_buffer(bh, WRITE_FLUSH_FUA);
1238 }
1239 
1240 static inline bool sanity_check_area_boundary(struct f2fs_sb_info *sbi,
1241 					struct buffer_head *bh)
1242 {
1243 	struct f2fs_super_block *raw_super = (struct f2fs_super_block *)
1244 					(bh->b_data + F2FS_SUPER_OFFSET);
1245 	struct super_block *sb = sbi->sb;
1246 	u32 segment0_blkaddr = le32_to_cpu(raw_super->segment0_blkaddr);
1247 	u32 cp_blkaddr = le32_to_cpu(raw_super->cp_blkaddr);
1248 	u32 sit_blkaddr = le32_to_cpu(raw_super->sit_blkaddr);
1249 	u32 nat_blkaddr = le32_to_cpu(raw_super->nat_blkaddr);
1250 	u32 ssa_blkaddr = le32_to_cpu(raw_super->ssa_blkaddr);
1251 	u32 main_blkaddr = le32_to_cpu(raw_super->main_blkaddr);
1252 	u32 segment_count_ckpt = le32_to_cpu(raw_super->segment_count_ckpt);
1253 	u32 segment_count_sit = le32_to_cpu(raw_super->segment_count_sit);
1254 	u32 segment_count_nat = le32_to_cpu(raw_super->segment_count_nat);
1255 	u32 segment_count_ssa = le32_to_cpu(raw_super->segment_count_ssa);
1256 	u32 segment_count_main = le32_to_cpu(raw_super->segment_count_main);
1257 	u32 segment_count = le32_to_cpu(raw_super->segment_count);
1258 	u32 log_blocks_per_seg = le32_to_cpu(raw_super->log_blocks_per_seg);
1259 	u64 main_end_blkaddr = main_blkaddr +
1260 				(segment_count_main << log_blocks_per_seg);
1261 	u64 seg_end_blkaddr = segment0_blkaddr +
1262 				(segment_count << log_blocks_per_seg);
1263 
1264 	if (segment0_blkaddr != cp_blkaddr) {
1265 		f2fs_msg(sb, KERN_INFO,
1266 			"Mismatch start address, segment0(%u) cp_blkaddr(%u)",
1267 			segment0_blkaddr, cp_blkaddr);
1268 		return true;
1269 	}
1270 
1271 	if (cp_blkaddr + (segment_count_ckpt << log_blocks_per_seg) !=
1272 							sit_blkaddr) {
1273 		f2fs_msg(sb, KERN_INFO,
1274 			"Wrong CP boundary, start(%u) end(%u) blocks(%u)",
1275 			cp_blkaddr, sit_blkaddr,
1276 			segment_count_ckpt << log_blocks_per_seg);
1277 		return true;
1278 	}
1279 
1280 	if (sit_blkaddr + (segment_count_sit << log_blocks_per_seg) !=
1281 							nat_blkaddr) {
1282 		f2fs_msg(sb, KERN_INFO,
1283 			"Wrong SIT boundary, start(%u) end(%u) blocks(%u)",
1284 			sit_blkaddr, nat_blkaddr,
1285 			segment_count_sit << log_blocks_per_seg);
1286 		return true;
1287 	}
1288 
1289 	if (nat_blkaddr + (segment_count_nat << log_blocks_per_seg) !=
1290 							ssa_blkaddr) {
1291 		f2fs_msg(sb, KERN_INFO,
1292 			"Wrong NAT boundary, start(%u) end(%u) blocks(%u)",
1293 			nat_blkaddr, ssa_blkaddr,
1294 			segment_count_nat << log_blocks_per_seg);
1295 		return true;
1296 	}
1297 
1298 	if (ssa_blkaddr + (segment_count_ssa << log_blocks_per_seg) !=
1299 							main_blkaddr) {
1300 		f2fs_msg(sb, KERN_INFO,
1301 			"Wrong SSA boundary, start(%u) end(%u) blocks(%u)",
1302 			ssa_blkaddr, main_blkaddr,
1303 			segment_count_ssa << log_blocks_per_seg);
1304 		return true;
1305 	}
1306 
1307 	if (main_end_blkaddr > seg_end_blkaddr) {
1308 		f2fs_msg(sb, KERN_INFO,
1309 			"Wrong MAIN_AREA boundary, start(%u) end(%u) block(%u)",
1310 			main_blkaddr,
1311 			segment0_blkaddr +
1312 				(segment_count << log_blocks_per_seg),
1313 			segment_count_main << log_blocks_per_seg);
1314 		return true;
1315 	} else if (main_end_blkaddr < seg_end_blkaddr) {
1316 		int err = 0;
1317 		char *res;
1318 
1319 		/* fix in-memory information all the time */
1320 		raw_super->segment_count = cpu_to_le32((main_end_blkaddr -
1321 				segment0_blkaddr) >> log_blocks_per_seg);
1322 
1323 		if (f2fs_readonly(sb) || bdev_read_only(sb->s_bdev)) {
1324 			set_sbi_flag(sbi, SBI_NEED_SB_WRITE);
1325 			res = "internally";
1326 		} else {
1327 			err = __f2fs_commit_super(bh, NULL);
1328 			res = err ? "failed" : "done";
1329 		}
1330 		f2fs_msg(sb, KERN_INFO,
1331 			"Fix alignment : %s, start(%u) end(%u) block(%u)",
1332 			res, main_blkaddr,
1333 			segment0_blkaddr +
1334 				(segment_count << log_blocks_per_seg),
1335 			segment_count_main << log_blocks_per_seg);
1336 		if (err)
1337 			return true;
1338 	}
1339 	return false;
1340 }
1341 
1342 static int sanity_check_raw_super(struct f2fs_sb_info *sbi,
1343 				struct buffer_head *bh)
1344 {
1345 	struct f2fs_super_block *raw_super = (struct f2fs_super_block *)
1346 					(bh->b_data + F2FS_SUPER_OFFSET);
1347 	struct super_block *sb = sbi->sb;
1348 	unsigned int blocksize;
1349 
1350 	if (F2FS_SUPER_MAGIC != le32_to_cpu(raw_super->magic)) {
1351 		f2fs_msg(sb, KERN_INFO,
1352 			"Magic Mismatch, valid(0x%x) - read(0x%x)",
1353 			F2FS_SUPER_MAGIC, le32_to_cpu(raw_super->magic));
1354 		return 1;
1355 	}
1356 
1357 	/* Currently, support only 4KB page cache size */
1358 	if (F2FS_BLKSIZE != PAGE_SIZE) {
1359 		f2fs_msg(sb, KERN_INFO,
1360 			"Invalid page_cache_size (%lu), supports only 4KB\n",
1361 			PAGE_SIZE);
1362 		return 1;
1363 	}
1364 
1365 	/* Currently, support only 4KB block size */
1366 	blocksize = 1 << le32_to_cpu(raw_super->log_blocksize);
1367 	if (blocksize != F2FS_BLKSIZE) {
1368 		f2fs_msg(sb, KERN_INFO,
1369 			"Invalid blocksize (%u), supports only 4KB\n",
1370 			blocksize);
1371 		return 1;
1372 	}
1373 
1374 	/* check log blocks per segment */
1375 	if (le32_to_cpu(raw_super->log_blocks_per_seg) != 9) {
1376 		f2fs_msg(sb, KERN_INFO,
1377 			"Invalid log blocks per segment (%u)\n",
1378 			le32_to_cpu(raw_super->log_blocks_per_seg));
1379 		return 1;
1380 	}
1381 
1382 	/* Currently, support 512/1024/2048/4096 bytes sector size */
1383 	if (le32_to_cpu(raw_super->log_sectorsize) >
1384 				F2FS_MAX_LOG_SECTOR_SIZE ||
1385 		le32_to_cpu(raw_super->log_sectorsize) <
1386 				F2FS_MIN_LOG_SECTOR_SIZE) {
1387 		f2fs_msg(sb, KERN_INFO, "Invalid log sectorsize (%u)",
1388 			le32_to_cpu(raw_super->log_sectorsize));
1389 		return 1;
1390 	}
1391 	if (le32_to_cpu(raw_super->log_sectors_per_block) +
1392 		le32_to_cpu(raw_super->log_sectorsize) !=
1393 			F2FS_MAX_LOG_SECTOR_SIZE) {
1394 		f2fs_msg(sb, KERN_INFO,
1395 			"Invalid log sectors per block(%u) log sectorsize(%u)",
1396 			le32_to_cpu(raw_super->log_sectors_per_block),
1397 			le32_to_cpu(raw_super->log_sectorsize));
1398 		return 1;
1399 	}
1400 
1401 	/* check reserved ino info */
1402 	if (le32_to_cpu(raw_super->node_ino) != 1 ||
1403 		le32_to_cpu(raw_super->meta_ino) != 2 ||
1404 		le32_to_cpu(raw_super->root_ino) != 3) {
1405 		f2fs_msg(sb, KERN_INFO,
1406 			"Invalid Fs Meta Ino: node(%u) meta(%u) root(%u)",
1407 			le32_to_cpu(raw_super->node_ino),
1408 			le32_to_cpu(raw_super->meta_ino),
1409 			le32_to_cpu(raw_super->root_ino));
1410 		return 1;
1411 	}
1412 
1413 	/* check CP/SIT/NAT/SSA/MAIN_AREA area boundary */
1414 	if (sanity_check_area_boundary(sbi, bh))
1415 		return 1;
1416 
1417 	return 0;
1418 }
1419 
1420 int sanity_check_ckpt(struct f2fs_sb_info *sbi)
1421 {
1422 	unsigned int total, fsmeta;
1423 	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
1424 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
1425 
1426 	total = le32_to_cpu(raw_super->segment_count);
1427 	fsmeta = le32_to_cpu(raw_super->segment_count_ckpt);
1428 	fsmeta += le32_to_cpu(raw_super->segment_count_sit);
1429 	fsmeta += le32_to_cpu(raw_super->segment_count_nat);
1430 	fsmeta += le32_to_cpu(ckpt->rsvd_segment_count);
1431 	fsmeta += le32_to_cpu(raw_super->segment_count_ssa);
1432 
1433 	if (unlikely(fsmeta >= total))
1434 		return 1;
1435 
1436 	if (unlikely(f2fs_cp_error(sbi))) {
1437 		f2fs_msg(sbi->sb, KERN_ERR, "A bug case: need to run fsck");
1438 		return 1;
1439 	}
1440 	return 0;
1441 }
1442 
1443 static void init_sb_info(struct f2fs_sb_info *sbi)
1444 {
1445 	struct f2fs_super_block *raw_super = sbi->raw_super;
1446 
1447 	sbi->log_sectors_per_block =
1448 		le32_to_cpu(raw_super->log_sectors_per_block);
1449 	sbi->log_blocksize = le32_to_cpu(raw_super->log_blocksize);
1450 	sbi->blocksize = 1 << sbi->log_blocksize;
1451 	sbi->log_blocks_per_seg = le32_to_cpu(raw_super->log_blocks_per_seg);
1452 	sbi->blocks_per_seg = 1 << sbi->log_blocks_per_seg;
1453 	sbi->segs_per_sec = le32_to_cpu(raw_super->segs_per_sec);
1454 	sbi->secs_per_zone = le32_to_cpu(raw_super->secs_per_zone);
1455 	sbi->total_sections = le32_to_cpu(raw_super->section_count);
1456 	sbi->total_node_count =
1457 		(le32_to_cpu(raw_super->segment_count_nat) / 2)
1458 			* sbi->blocks_per_seg * NAT_ENTRY_PER_BLOCK;
1459 	sbi->root_ino_num = le32_to_cpu(raw_super->root_ino);
1460 	sbi->node_ino_num = le32_to_cpu(raw_super->node_ino);
1461 	sbi->meta_ino_num = le32_to_cpu(raw_super->meta_ino);
1462 	sbi->cur_victim_sec = NULL_SECNO;
1463 	sbi->max_victim_search = DEF_MAX_VICTIM_SEARCH;
1464 
1465 	sbi->dir_level = DEF_DIR_LEVEL;
1466 	sbi->interval_time[CP_TIME] = DEF_CP_INTERVAL;
1467 	sbi->interval_time[REQ_TIME] = DEF_IDLE_INTERVAL;
1468 	clear_sbi_flag(sbi, SBI_NEED_FSCK);
1469 
1470 	INIT_LIST_HEAD(&sbi->s_list);
1471 	mutex_init(&sbi->umount_mutex);
1472 	mutex_init(&sbi->wio_mutex[NODE]);
1473 	mutex_init(&sbi->wio_mutex[DATA]);
1474 
1475 #ifdef CONFIG_F2FS_FS_ENCRYPTION
1476 	memcpy(sbi->key_prefix, F2FS_KEY_DESC_PREFIX,
1477 				F2FS_KEY_DESC_PREFIX_SIZE);
1478 	sbi->key_prefix_size = F2FS_KEY_DESC_PREFIX_SIZE;
1479 #endif
1480 }
1481 
1482 static int init_percpu_info(struct f2fs_sb_info *sbi)
1483 {
1484 	int i, err;
1485 
1486 	if (percpu_init_rwsem(&sbi->cp_rwsem))
1487 		return -ENOMEM;
1488 
1489 	for (i = 0; i < NR_COUNT_TYPE; i++) {
1490 		err = percpu_counter_init(&sbi->nr_pages[i], 0, GFP_KERNEL);
1491 		if (err)
1492 			return err;
1493 	}
1494 
1495 	err = percpu_counter_init(&sbi->alloc_valid_block_count, 0, GFP_KERNEL);
1496 	if (err)
1497 		return err;
1498 
1499 	return percpu_counter_init(&sbi->total_valid_inode_count, 0,
1500 								GFP_KERNEL);
1501 }
1502 
1503 /*
1504  * Read f2fs raw super block.
1505  * Because we have two copies of super block, so read both of them
1506  * to get the first valid one. If any one of them is broken, we pass
1507  * them recovery flag back to the caller.
1508  */
1509 static int read_raw_super_block(struct f2fs_sb_info *sbi,
1510 			struct f2fs_super_block **raw_super,
1511 			int *valid_super_block, int *recovery)
1512 {
1513 	struct super_block *sb = sbi->sb;
1514 	int block;
1515 	struct buffer_head *bh;
1516 	struct f2fs_super_block *super;
1517 	int err = 0;
1518 
1519 	super = kzalloc(sizeof(struct f2fs_super_block), GFP_KERNEL);
1520 	if (!super)
1521 		return -ENOMEM;
1522 
1523 	for (block = 0; block < 2; block++) {
1524 		bh = sb_bread(sb, block);
1525 		if (!bh) {
1526 			f2fs_msg(sb, KERN_ERR, "Unable to read %dth superblock",
1527 				block + 1);
1528 			err = -EIO;
1529 			continue;
1530 		}
1531 
1532 		/* sanity checking of raw super */
1533 		if (sanity_check_raw_super(sbi, bh)) {
1534 			f2fs_msg(sb, KERN_ERR,
1535 				"Can't find valid F2FS filesystem in %dth superblock",
1536 				block + 1);
1537 			err = -EINVAL;
1538 			brelse(bh);
1539 			continue;
1540 		}
1541 
1542 		if (!*raw_super) {
1543 			memcpy(super, bh->b_data + F2FS_SUPER_OFFSET,
1544 							sizeof(*super));
1545 			*valid_super_block = block;
1546 			*raw_super = super;
1547 		}
1548 		brelse(bh);
1549 	}
1550 
1551 	/* Fail to read any one of the superblocks*/
1552 	if (err < 0)
1553 		*recovery = 1;
1554 
1555 	/* No valid superblock */
1556 	if (!*raw_super)
1557 		kfree(super);
1558 	else
1559 		err = 0;
1560 
1561 	return err;
1562 }
1563 
1564 int f2fs_commit_super(struct f2fs_sb_info *sbi, bool recover)
1565 {
1566 	struct buffer_head *bh;
1567 	int err;
1568 
1569 	if ((recover && f2fs_readonly(sbi->sb)) ||
1570 				bdev_read_only(sbi->sb->s_bdev)) {
1571 		set_sbi_flag(sbi, SBI_NEED_SB_WRITE);
1572 		return -EROFS;
1573 	}
1574 
1575 	/* write back-up superblock first */
1576 	bh = sb_getblk(sbi->sb, sbi->valid_super_block ? 0: 1);
1577 	if (!bh)
1578 		return -EIO;
1579 	err = __f2fs_commit_super(bh, F2FS_RAW_SUPER(sbi));
1580 	brelse(bh);
1581 
1582 	/* if we are in recovery path, skip writing valid superblock */
1583 	if (recover || err)
1584 		return err;
1585 
1586 	/* write current valid superblock */
1587 	bh = sb_getblk(sbi->sb, sbi->valid_super_block);
1588 	if (!bh)
1589 		return -EIO;
1590 	err = __f2fs_commit_super(bh, F2FS_RAW_SUPER(sbi));
1591 	brelse(bh);
1592 	return err;
1593 }
1594 
1595 static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
1596 {
1597 	struct f2fs_sb_info *sbi;
1598 	struct f2fs_super_block *raw_super;
1599 	struct inode *root;
1600 	int err;
1601 	bool retry = true, need_fsck = false;
1602 	char *options = NULL;
1603 	int recovery, i, valid_super_block;
1604 	struct curseg_info *seg_i;
1605 
1606 try_onemore:
1607 	err = -EINVAL;
1608 	raw_super = NULL;
1609 	valid_super_block = -1;
1610 	recovery = 0;
1611 
1612 	/* allocate memory for f2fs-specific super block info */
1613 	sbi = kzalloc(sizeof(struct f2fs_sb_info), GFP_KERNEL);
1614 	if (!sbi)
1615 		return -ENOMEM;
1616 
1617 	sbi->sb = sb;
1618 
1619 	/* Load the checksum driver */
1620 	sbi->s_chksum_driver = crypto_alloc_shash("crc32", 0, 0);
1621 	if (IS_ERR(sbi->s_chksum_driver)) {
1622 		f2fs_msg(sb, KERN_ERR, "Cannot load crc32 driver.");
1623 		err = PTR_ERR(sbi->s_chksum_driver);
1624 		sbi->s_chksum_driver = NULL;
1625 		goto free_sbi;
1626 	}
1627 
1628 	/* set a block size */
1629 	if (unlikely(!sb_set_blocksize(sb, F2FS_BLKSIZE))) {
1630 		f2fs_msg(sb, KERN_ERR, "unable to set blocksize");
1631 		goto free_sbi;
1632 	}
1633 
1634 	err = read_raw_super_block(sbi, &raw_super, &valid_super_block,
1635 								&recovery);
1636 	if (err)
1637 		goto free_sbi;
1638 
1639 	sb->s_fs_info = sbi;
1640 	sbi->raw_super = raw_super;
1641 
1642 	default_options(sbi);
1643 	/* parse mount options */
1644 	options = kstrdup((const char *)data, GFP_KERNEL);
1645 	if (data && !options) {
1646 		err = -ENOMEM;
1647 		goto free_sb_buf;
1648 	}
1649 
1650 	err = parse_options(sb, options);
1651 	if (err)
1652 		goto free_options;
1653 
1654 	sbi->max_file_blocks = max_file_blocks();
1655 	sb->s_maxbytes = sbi->max_file_blocks <<
1656 				le32_to_cpu(raw_super->log_blocksize);
1657 	sb->s_max_links = F2FS_LINK_MAX;
1658 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1659 
1660 	sb->s_op = &f2fs_sops;
1661 	sb->s_cop = &f2fs_cryptops;
1662 	sb->s_xattr = f2fs_xattr_handlers;
1663 	sb->s_export_op = &f2fs_export_ops;
1664 	sb->s_magic = F2FS_SUPER_MAGIC;
1665 	sb->s_time_gran = 1;
1666 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1667 		(test_opt(sbi, POSIX_ACL) ? MS_POSIXACL : 0);
1668 	memcpy(sb->s_uuid, raw_super->uuid, sizeof(raw_super->uuid));
1669 
1670 	/* init f2fs-specific super block info */
1671 	sbi->valid_super_block = valid_super_block;
1672 	mutex_init(&sbi->gc_mutex);
1673 	mutex_init(&sbi->cp_mutex);
1674 	init_rwsem(&sbi->node_write);
1675 
1676 	/* disallow all the data/node/meta page writes */
1677 	set_sbi_flag(sbi, SBI_POR_DOING);
1678 	spin_lock_init(&sbi->stat_lock);
1679 
1680 	init_rwsem(&sbi->read_io.io_rwsem);
1681 	sbi->read_io.sbi = sbi;
1682 	sbi->read_io.bio = NULL;
1683 	for (i = 0; i < NR_PAGE_TYPE; i++) {
1684 		init_rwsem(&sbi->write_io[i].io_rwsem);
1685 		sbi->write_io[i].sbi = sbi;
1686 		sbi->write_io[i].bio = NULL;
1687 	}
1688 
1689 	init_waitqueue_head(&sbi->cp_wait);
1690 	init_sb_info(sbi);
1691 
1692 	err = init_percpu_info(sbi);
1693 	if (err)
1694 		goto free_options;
1695 
1696 	/* get an inode for meta space */
1697 	sbi->meta_inode = f2fs_iget(sb, F2FS_META_INO(sbi));
1698 	if (IS_ERR(sbi->meta_inode)) {
1699 		f2fs_msg(sb, KERN_ERR, "Failed to read F2FS meta data inode");
1700 		err = PTR_ERR(sbi->meta_inode);
1701 		goto free_options;
1702 	}
1703 
1704 	err = get_valid_checkpoint(sbi);
1705 	if (err) {
1706 		f2fs_msg(sb, KERN_ERR, "Failed to get valid F2FS checkpoint");
1707 		goto free_meta_inode;
1708 	}
1709 
1710 	sbi->total_valid_node_count =
1711 				le32_to_cpu(sbi->ckpt->valid_node_count);
1712 	percpu_counter_set(&sbi->total_valid_inode_count,
1713 				le32_to_cpu(sbi->ckpt->valid_inode_count));
1714 	sbi->user_block_count = le64_to_cpu(sbi->ckpt->user_block_count);
1715 	sbi->total_valid_block_count =
1716 				le64_to_cpu(sbi->ckpt->valid_block_count);
1717 	sbi->last_valid_block_count = sbi->total_valid_block_count;
1718 
1719 	for (i = 0; i < NR_INODE_TYPE; i++) {
1720 		INIT_LIST_HEAD(&sbi->inode_list[i]);
1721 		spin_lock_init(&sbi->inode_lock[i]);
1722 	}
1723 
1724 	init_extent_cache_info(sbi);
1725 
1726 	init_ino_entry_info(sbi);
1727 
1728 	/* setup f2fs internal modules */
1729 	err = build_segment_manager(sbi);
1730 	if (err) {
1731 		f2fs_msg(sb, KERN_ERR,
1732 			"Failed to initialize F2FS segment manager");
1733 		goto free_sm;
1734 	}
1735 	err = build_node_manager(sbi);
1736 	if (err) {
1737 		f2fs_msg(sb, KERN_ERR,
1738 			"Failed to initialize F2FS node manager");
1739 		goto free_nm;
1740 	}
1741 
1742 	/* For write statistics */
1743 	if (sb->s_bdev->bd_part)
1744 		sbi->sectors_written_start =
1745 			(u64)part_stat_read(sb->s_bdev->bd_part, sectors[1]);
1746 
1747 	/* Read accumulated write IO statistics if exists */
1748 	seg_i = CURSEG_I(sbi, CURSEG_HOT_NODE);
1749 	if (__exist_node_summaries(sbi))
1750 		sbi->kbytes_written =
1751 			le64_to_cpu(seg_i->journal->info.kbytes_written);
1752 
1753 	build_gc_manager(sbi);
1754 
1755 	/* get an inode for node space */
1756 	sbi->node_inode = f2fs_iget(sb, F2FS_NODE_INO(sbi));
1757 	if (IS_ERR(sbi->node_inode)) {
1758 		f2fs_msg(sb, KERN_ERR, "Failed to read node inode");
1759 		err = PTR_ERR(sbi->node_inode);
1760 		goto free_nm;
1761 	}
1762 
1763 	f2fs_join_shrinker(sbi);
1764 
1765 	/* if there are nt orphan nodes free them */
1766 	err = recover_orphan_inodes(sbi);
1767 	if (err)
1768 		goto free_node_inode;
1769 
1770 	/* read root inode and dentry */
1771 	root = f2fs_iget(sb, F2FS_ROOT_INO(sbi));
1772 	if (IS_ERR(root)) {
1773 		f2fs_msg(sb, KERN_ERR, "Failed to read root inode");
1774 		err = PTR_ERR(root);
1775 		goto free_node_inode;
1776 	}
1777 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1778 		iput(root);
1779 		err = -EINVAL;
1780 		goto free_node_inode;
1781 	}
1782 
1783 	sb->s_root = d_make_root(root); /* allocate root dentry */
1784 	if (!sb->s_root) {
1785 		err = -ENOMEM;
1786 		goto free_root_inode;
1787 	}
1788 
1789 	err = f2fs_build_stats(sbi);
1790 	if (err)
1791 		goto free_root_inode;
1792 
1793 	if (f2fs_proc_root)
1794 		sbi->s_proc = proc_mkdir(sb->s_id, f2fs_proc_root);
1795 
1796 	if (sbi->s_proc) {
1797 		proc_create_data("segment_info", S_IRUGO, sbi->s_proc,
1798 				 &f2fs_seq_segment_info_fops, sb);
1799 		proc_create_data("segment_bits", S_IRUGO, sbi->s_proc,
1800 				 &f2fs_seq_segment_bits_fops, sb);
1801 	}
1802 
1803 	sbi->s_kobj.kset = f2fs_kset;
1804 	init_completion(&sbi->s_kobj_unregister);
1805 	err = kobject_init_and_add(&sbi->s_kobj, &f2fs_ktype, NULL,
1806 							"%s", sb->s_id);
1807 	if (err)
1808 		goto free_proc;
1809 
1810 	/* recover fsynced data */
1811 	if (!test_opt(sbi, DISABLE_ROLL_FORWARD)) {
1812 		/*
1813 		 * mount should be failed, when device has readonly mode, and
1814 		 * previous checkpoint was not done by clean system shutdown.
1815 		 */
1816 		if (bdev_read_only(sb->s_bdev) &&
1817 				!is_set_ckpt_flags(sbi->ckpt, CP_UMOUNT_FLAG)) {
1818 			err = -EROFS;
1819 			goto free_kobj;
1820 		}
1821 
1822 		if (need_fsck)
1823 			set_sbi_flag(sbi, SBI_NEED_FSCK);
1824 
1825 		err = recover_fsync_data(sbi, false);
1826 		if (err < 0) {
1827 			need_fsck = true;
1828 			f2fs_msg(sb, KERN_ERR,
1829 				"Cannot recover all fsync data errno=%d", err);
1830 			goto free_kobj;
1831 		}
1832 	} else {
1833 		err = recover_fsync_data(sbi, true);
1834 
1835 		if (!f2fs_readonly(sb) && err > 0) {
1836 			err = -EINVAL;
1837 			f2fs_msg(sb, KERN_ERR,
1838 				"Need to recover fsync data");
1839 			goto free_kobj;
1840 		}
1841 	}
1842 
1843 	/* recover_fsync_data() cleared this already */
1844 	clear_sbi_flag(sbi, SBI_POR_DOING);
1845 
1846 	/*
1847 	 * If filesystem is not mounted as read-only then
1848 	 * do start the gc_thread.
1849 	 */
1850 	if (test_opt(sbi, BG_GC) && !f2fs_readonly(sb)) {
1851 		/* After POR, we can run background GC thread.*/
1852 		err = start_gc_thread(sbi);
1853 		if (err)
1854 			goto free_kobj;
1855 	}
1856 	kfree(options);
1857 
1858 	/* recover broken superblock */
1859 	if (recovery) {
1860 		err = f2fs_commit_super(sbi, true);
1861 		f2fs_msg(sb, KERN_INFO,
1862 			"Try to recover %dth superblock, ret: %d",
1863 			sbi->valid_super_block ? 1 : 2, err);
1864 	}
1865 
1866 	f2fs_update_time(sbi, CP_TIME);
1867 	f2fs_update_time(sbi, REQ_TIME);
1868 	return 0;
1869 
1870 free_kobj:
1871 	f2fs_sync_inode_meta(sbi);
1872 	kobject_del(&sbi->s_kobj);
1873 	kobject_put(&sbi->s_kobj);
1874 	wait_for_completion(&sbi->s_kobj_unregister);
1875 free_proc:
1876 	if (sbi->s_proc) {
1877 		remove_proc_entry("segment_info", sbi->s_proc);
1878 		remove_proc_entry("segment_bits", sbi->s_proc);
1879 		remove_proc_entry(sb->s_id, f2fs_proc_root);
1880 	}
1881 	f2fs_destroy_stats(sbi);
1882 free_root_inode:
1883 	dput(sb->s_root);
1884 	sb->s_root = NULL;
1885 free_node_inode:
1886 	mutex_lock(&sbi->umount_mutex);
1887 	f2fs_leave_shrinker(sbi);
1888 	iput(sbi->node_inode);
1889 	mutex_unlock(&sbi->umount_mutex);
1890 free_nm:
1891 	destroy_node_manager(sbi);
1892 free_sm:
1893 	destroy_segment_manager(sbi);
1894 	kfree(sbi->ckpt);
1895 free_meta_inode:
1896 	make_bad_inode(sbi->meta_inode);
1897 	iput(sbi->meta_inode);
1898 free_options:
1899 	destroy_percpu_info(sbi);
1900 	kfree(options);
1901 free_sb_buf:
1902 	kfree(raw_super);
1903 free_sbi:
1904 	if (sbi->s_chksum_driver)
1905 		crypto_free_shash(sbi->s_chksum_driver);
1906 	kfree(sbi);
1907 
1908 	/* give only one another chance */
1909 	if (retry) {
1910 		retry = false;
1911 		shrink_dcache_sb(sb);
1912 		goto try_onemore;
1913 	}
1914 	return err;
1915 }
1916 
1917 static struct dentry *f2fs_mount(struct file_system_type *fs_type, int flags,
1918 			const char *dev_name, void *data)
1919 {
1920 	return mount_bdev(fs_type, flags, dev_name, data, f2fs_fill_super);
1921 }
1922 
1923 static void kill_f2fs_super(struct super_block *sb)
1924 {
1925 	if (sb->s_root)
1926 		set_sbi_flag(F2FS_SB(sb), SBI_IS_CLOSE);
1927 	kill_block_super(sb);
1928 }
1929 
1930 static struct file_system_type f2fs_fs_type = {
1931 	.owner		= THIS_MODULE,
1932 	.name		= "f2fs",
1933 	.mount		= f2fs_mount,
1934 	.kill_sb	= kill_f2fs_super,
1935 	.fs_flags	= FS_REQUIRES_DEV,
1936 };
1937 MODULE_ALIAS_FS("f2fs");
1938 
1939 static int __init init_inodecache(void)
1940 {
1941 	f2fs_inode_cachep = kmem_cache_create("f2fs_inode_cache",
1942 			sizeof(struct f2fs_inode_info), 0,
1943 			SLAB_RECLAIM_ACCOUNT|SLAB_ACCOUNT, NULL);
1944 	if (!f2fs_inode_cachep)
1945 		return -ENOMEM;
1946 	return 0;
1947 }
1948 
1949 static void destroy_inodecache(void)
1950 {
1951 	/*
1952 	 * Make sure all delayed rcu free inodes are flushed before we
1953 	 * destroy cache.
1954 	 */
1955 	rcu_barrier();
1956 	kmem_cache_destroy(f2fs_inode_cachep);
1957 }
1958 
1959 static int __init init_f2fs_fs(void)
1960 {
1961 	int err;
1962 
1963 	f2fs_build_trace_ios();
1964 
1965 	err = init_inodecache();
1966 	if (err)
1967 		goto fail;
1968 	err = create_node_manager_caches();
1969 	if (err)
1970 		goto free_inodecache;
1971 	err = create_segment_manager_caches();
1972 	if (err)
1973 		goto free_node_manager_caches;
1974 	err = create_checkpoint_caches();
1975 	if (err)
1976 		goto free_segment_manager_caches;
1977 	err = create_extent_cache();
1978 	if (err)
1979 		goto free_checkpoint_caches;
1980 	f2fs_kset = kset_create_and_add("f2fs", NULL, fs_kobj);
1981 	if (!f2fs_kset) {
1982 		err = -ENOMEM;
1983 		goto free_extent_cache;
1984 	}
1985 #ifdef CONFIG_F2FS_FAULT_INJECTION
1986 	f2fs_fault_inject.kset = f2fs_kset;
1987 	f2fs_build_fault_attr(0);
1988 	err = kobject_init_and_add(&f2fs_fault_inject, &f2fs_fault_ktype,
1989 				NULL, "fault_injection");
1990 	if (err) {
1991 		f2fs_fault_inject.kset = NULL;
1992 		goto free_kset;
1993 	}
1994 #endif
1995 	err = register_shrinker(&f2fs_shrinker_info);
1996 	if (err)
1997 		goto free_kset;
1998 
1999 	err = register_filesystem(&f2fs_fs_type);
2000 	if (err)
2001 		goto free_shrinker;
2002 	err = f2fs_create_root_stats();
2003 	if (err)
2004 		goto free_filesystem;
2005 	f2fs_proc_root = proc_mkdir("fs/f2fs", NULL);
2006 	return 0;
2007 
2008 free_filesystem:
2009 	unregister_filesystem(&f2fs_fs_type);
2010 free_shrinker:
2011 	unregister_shrinker(&f2fs_shrinker_info);
2012 free_kset:
2013 #ifdef CONFIG_F2FS_FAULT_INJECTION
2014 	if (f2fs_fault_inject.kset)
2015 		kobject_put(&f2fs_fault_inject);
2016 #endif
2017 	kset_unregister(f2fs_kset);
2018 free_extent_cache:
2019 	destroy_extent_cache();
2020 free_checkpoint_caches:
2021 	destroy_checkpoint_caches();
2022 free_segment_manager_caches:
2023 	destroy_segment_manager_caches();
2024 free_node_manager_caches:
2025 	destroy_node_manager_caches();
2026 free_inodecache:
2027 	destroy_inodecache();
2028 fail:
2029 	return err;
2030 }
2031 
2032 static void __exit exit_f2fs_fs(void)
2033 {
2034 	remove_proc_entry("fs/f2fs", NULL);
2035 	f2fs_destroy_root_stats();
2036 	unregister_filesystem(&f2fs_fs_type);
2037 	unregister_shrinker(&f2fs_shrinker_info);
2038 #ifdef CONFIG_F2FS_FAULT_INJECTION
2039 	kobject_put(&f2fs_fault_inject);
2040 #endif
2041 	kset_unregister(f2fs_kset);
2042 	destroy_extent_cache();
2043 	destroy_checkpoint_caches();
2044 	destroy_segment_manager_caches();
2045 	destroy_node_manager_caches();
2046 	destroy_inodecache();
2047 	f2fs_destroy_trace_ios();
2048 }
2049 
2050 module_init(init_f2fs_fs)
2051 module_exit(exit_f2fs_fs)
2052 
2053 MODULE_AUTHOR("Samsung Electronics's Praesto Team");
2054 MODULE_DESCRIPTION("Flash Friendly File System");
2055 MODULE_LICENSE("GPL");
2056