Initial import

1 files changed, 1350 insertions, 0 deletions

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
new file mode 100644
index 000000000..b2dd1b01f
--- /dev/null
+++ b/fs/f2fs/super.c
@@ -0,0 +1,1350 @@
+/*
+ * fs/f2fs/super.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/statfs.h>
+#include <linux/buffer_head.h>
+#include <linux/backing-dev.h>
+#include <linux/kthread.h>
+#include <linux/parser.h>
+#include <linux/mount.h>
+#include <linux/seq_file.h>
+#include <linux/proc_fs.h>
+#include <linux/random.h>
+#include <linux/exportfs.h>
+#include <linux/blkdev.h>
+#include <linux/f2fs_fs.h>
+#include <linux/sysfs.h>
+
+#include "f2fs.h"
+#include "node.h"
+#include "segment.h"
+#include "xattr.h"
+#include "gc.h"
+#include "trace.h"
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/f2fs.h>
+
+static struct proc_dir_entry *f2fs_proc_root;
+static struct kmem_cache *f2fs_inode_cachep;
+static struct kset *f2fs_kset;
+
+enum {
+	Opt_gc_background,
+	Opt_disable_roll_forward,
+	Opt_norecovery,
+	Opt_discard,
+	Opt_noheap,
+	Opt_user_xattr,
+	Opt_nouser_xattr,
+	Opt_acl,
+	Opt_noacl,
+	Opt_active_logs,
+	Opt_disable_ext_identify,
+	Opt_inline_xattr,
+	Opt_inline_data,
+	Opt_inline_dentry,
+	Opt_flush_merge,
+	Opt_nobarrier,
+	Opt_fastboot,
+	Opt_extent_cache,
+	Opt_noinline_data,
+	Opt_err,
+};
+
+static match_table_t f2fs_tokens = {
+	{Opt_gc_background, "background_gc=%s"},
+	{Opt_disable_roll_forward, "disable_roll_forward"},
+	{Opt_norecovery, "norecovery"},
+	{Opt_discard, "discard"},
+	{Opt_noheap, "no_heap"},
+	{Opt_user_xattr, "user_xattr"},
+	{Opt_nouser_xattr, "nouser_xattr"},
+	{Opt_acl, "acl"},
+	{Opt_noacl, "noacl"},
+	{Opt_active_logs, "active_logs=%u"},
+	{Opt_disable_ext_identify, "disable_ext_identify"},
+	{Opt_inline_xattr, "inline_xattr"},
+	{Opt_inline_data, "inline_data"},
+	{Opt_inline_dentry, "inline_dentry"},
+	{Opt_flush_merge, "flush_merge"},
+	{Opt_nobarrier, "nobarrier"},
+	{Opt_fastboot, "fastboot"},
+	{Opt_extent_cache, "extent_cache"},
+	{Opt_noinline_data, "noinline_data"},
+	{Opt_err, NULL},
+};
+
+/* Sysfs support for f2fs */
+enum {
+	GC_THREAD,	/* struct f2fs_gc_thread */
+	SM_INFO,	/* struct f2fs_sm_info */
+	NM_INFO,	/* struct f2fs_nm_info */
+	F2FS_SBI,	/* struct f2fs_sb_info */
+};
+
+struct f2fs_attr {
+	struct attribute attr;
+	ssize_t (*show)(struct f2fs_attr *, struct f2fs_sb_info *, char *);
+	ssize_t (*store)(struct f2fs_attr *, struct f2fs_sb_info *,
+			 const char *, size_t);
+	int struct_type;
+	int offset;
+};
+
+static unsigned char *__struct_ptr(struct f2fs_sb_info *sbi, int struct_type)
+{
+	if (struct_type == GC_THREAD)
+		return (unsigned char *)sbi->gc_thread;
+	else if (struct_type == SM_INFO)
+		return (unsigned char *)SM_I(sbi);
+	else if (struct_type == NM_INFO)
+		return (unsigned char *)NM_I(sbi);
+	else if (struct_type == F2FS_SBI)
+		return (unsigned char *)sbi;
+	return NULL;
+}
+
+static ssize_t f2fs_sbi_show(struct f2fs_attr *a,
+			struct f2fs_sb_info *sbi, char *buf)
+{
+	unsigned char *ptr = NULL;
+	unsigned int *ui;
+
+	ptr = __struct_ptr(sbi, a->struct_type);
+	if (!ptr)
+		return -EINVAL;
+
+	ui = (unsigned int *)(ptr + a->offset);
+
+	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
+}
+
+static ssize_t f2fs_sbi_store(struct f2fs_attr *a,
+			struct f2fs_sb_info *sbi,
+			const char *buf, size_t count)
+{
+	unsigned char *ptr;
+	unsigned long t;
+	unsigned int *ui;
+	ssize_t ret;
+
+	ptr = __struct_ptr(sbi, a->struct_type);
+	if (!ptr)
+		return -EINVAL;
+
+	ui = (unsigned int *)(ptr + a->offset);
+
+	ret = kstrtoul(skip_spaces(buf), 0, &t);
+	if (ret < 0)
+		return ret;
+	*ui = t;
+	return count;
+}
+
+static ssize_t f2fs_attr_show(struct kobject *kobj,
+				struct attribute *attr, char *buf)
+{
+	struct f2fs_sb_info *sbi = container_of(kobj, struct f2fs_sb_info,
+								s_kobj);
+	struct f2fs_attr *a = container_of(attr, struct f2fs_attr, attr);
+
+	return a->show ? a->show(a, sbi, buf) : 0;
+}
+
+static ssize_t f2fs_attr_store(struct kobject *kobj, struct attribute *attr,
+						const char *buf, size_t len)
+{
+	struct f2fs_sb_info *sbi = container_of(kobj, struct f2fs_sb_info,
+									s_kobj);
+	struct f2fs_attr *a = container_of(attr, struct f2fs_attr, attr);
+
+	return a->store ? a->store(a, sbi, buf, len) : 0;
+}
+
+static void f2fs_sb_release(struct kobject *kobj)
+{
+	struct f2fs_sb_info *sbi = container_of(kobj, struct f2fs_sb_info,
+								s_kobj);
+	complete(&sbi->s_kobj_unregister);
+}
+
+#define F2FS_ATTR_OFFSET(_struct_type, _name, _mode, _show, _store, _offset) \
+static struct f2fs_attr f2fs_attr_##_name = {			\
+	.attr = {.name = __stringify(_name), .mode = _mode },	\
+	.show	= _show,					\
+	.store	= _store,					\
+	.struct_type = _struct_type,				\
+	.offset = _offset					\
+}
+
+#define F2FS_RW_ATTR(struct_type, struct_name, name, elname)	\
+	F2FS_ATTR_OFFSET(struct_type, name, 0644,		\
+		f2fs_sbi_show, f2fs_sbi_store,			\
+		offsetof(struct struct_name, elname))
+
+F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_min_sleep_time, min_sleep_time);
+F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_max_sleep_time, max_sleep_time);
+F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_no_gc_sleep_time, no_gc_sleep_time);
+F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_idle, gc_idle);
+F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, reclaim_segments, rec_prefree_segments);
+F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, max_small_discards, max_discards);
+F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, batched_trim_sections, trim_sections);
+F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, ipu_policy, ipu_policy);
+F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_ipu_util, min_ipu_util);
+F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_fsync_blocks, min_fsync_blocks);
+F2FS_RW_ATTR(NM_INFO, f2fs_nm_info, ram_thresh, ram_thresh);
+F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, max_victim_search, max_victim_search);
+F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, dir_level, dir_level);
+
+#define ATTR_LIST(name) (&f2fs_attr_##name.attr)
+static struct attribute *f2fs_attrs[] = {
+	ATTR_LIST(gc_min_sleep_time),
+	ATTR_LIST(gc_max_sleep_time),
+	ATTR_LIST(gc_no_gc_sleep_time),
+	ATTR_LIST(gc_idle),
+	ATTR_LIST(reclaim_segments),
+	ATTR_LIST(max_small_discards),
+	ATTR_LIST(batched_trim_sections),
+	ATTR_LIST(ipu_policy),
+	ATTR_LIST(min_ipu_util),
+	ATTR_LIST(min_fsync_blocks),
+	ATTR_LIST(max_victim_search),
+	ATTR_LIST(dir_level),
+	ATTR_LIST(ram_thresh),
+	NULL,
+};
+
+static const struct sysfs_ops f2fs_attr_ops = {
+	.show	= f2fs_attr_show,
+	.store	= f2fs_attr_store,
+};
+
+static struct kobj_type f2fs_ktype = {
+	.default_attrs	= f2fs_attrs,
+	.sysfs_ops	= &f2fs_attr_ops,
+	.release	= f2fs_sb_release,
+};
+
+void f2fs_msg(struct super_block *sb, const char *level, const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+
+	va_start(args, fmt);
+	vaf.fmt = fmt;
+	vaf.va = &args;
+	printk("%sF2FS-fs (%s): %pV\n", level, sb->s_id, &vaf);
+	va_end(args);
+}
+
+static void init_once(void *foo)
+{
+	struct f2fs_inode_info *fi = (struct f2fs_inode_info *) foo;
+
+	inode_init_once(&fi->vfs_inode);
+}
+
+static int parse_options(struct super_block *sb, char *options)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+	substring_t args[MAX_OPT_ARGS];
+	char *p, *name;
+	int arg = 0;
+
+	if (!options)
+		return 0;
+
+	while ((p = strsep(&options, ",")) != NULL) {
+		int token;
+		if (!*p)
+			continue;
+		/*
+		 * Initialize args struct so we know whether arg was
+		 * found; some options take optional arguments.
+		 */
+		args[0].to = args[0].from = NULL;
+		token = match_token(p, f2fs_tokens, args);
+
+		switch (token) {
+		case Opt_gc_background:
+			name = match_strdup(&args[0]);
+
+			if (!name)
+				return -ENOMEM;
+			if (strlen(name) == 2 && !strncmp(name, "on", 2))
+				set_opt(sbi, BG_GC);
+			else if (strlen(name) == 3 && !strncmp(name, "off", 3))
+				clear_opt(sbi, BG_GC);
+			else {
+				kfree(name);
+				return -EINVAL;
+			}
+			kfree(name);
+			break;
+		case Opt_disable_roll_forward:
+			set_opt(sbi, DISABLE_ROLL_FORWARD);
+			break;
+		case Opt_norecovery:
+			/* this option mounts f2fs with ro */
+			set_opt(sbi, DISABLE_ROLL_FORWARD);
+			if (!f2fs_readonly(sb))
+				return -EINVAL;
+			break;
+		case Opt_discard:
+			set_opt(sbi, DISCARD);
+			break;
+		case Opt_noheap:
+			set_opt(sbi, NOHEAP);
+			break;
+#ifdef CONFIG_F2FS_FS_XATTR
+		case Opt_user_xattr:
+			set_opt(sbi, XATTR_USER);
+			break;
+		case Opt_nouser_xattr:
+			clear_opt(sbi, XATTR_USER);
+			break;
+		case Opt_inline_xattr:
+			set_opt(sbi, INLINE_XATTR);
+			break;
+#else
+		case Opt_user_xattr:
+			f2fs_msg(sb, KERN_INFO,
+				"user_xattr options not supported");
+			break;
+		case Opt_nouser_xattr:
+			f2fs_msg(sb, KERN_INFO,
+				"nouser_xattr options not supported");
+			break;
+		case Opt_inline_xattr:
+			f2fs_msg(sb, KERN_INFO,
+				"inline_xattr options not supported");
+			break;
+#endif
+#ifdef CONFIG_F2FS_FS_POSIX_ACL
+		case Opt_acl:
+			set_opt(sbi, POSIX_ACL);
+			break;
+		case Opt_noacl:
+			clear_opt(sbi, POSIX_ACL);
+			break;
+#else
+		case Opt_acl:
+			f2fs_msg(sb, KERN_INFO, "acl options not supported");
+			break;
+		case Opt_noacl:
+			f2fs_msg(sb, KERN_INFO, "noacl options not supported");
+			break;
+#endif
+		case Opt_active_logs:
+			if (args->from && match_int(args, &arg))
+				return -EINVAL;
+			if (arg != 2 && arg != 4 && arg != NR_CURSEG_TYPE)
+				return -EINVAL;
+			sbi->active_logs = arg;
+			break;
+		case Opt_disable_ext_identify:
+			set_opt(sbi, DISABLE_EXT_IDENTIFY);
+			break;
+		case Opt_inline_data:
+			set_opt(sbi, INLINE_DATA);
+			break;
+		case Opt_inline_dentry:
+			set_opt(sbi, INLINE_DENTRY);
+			break;
+		case Opt_flush_merge:
+			set_opt(sbi, FLUSH_MERGE);
+			break;
+		case Opt_nobarrier:
+			set_opt(sbi, NOBARRIER);
+			break;
+		case Opt_fastboot:
+			set_opt(sbi, FASTBOOT);
+			break;
+		case Opt_extent_cache:
+			set_opt(sbi, EXTENT_CACHE);
+			break;
+		case Opt_noinline_data:
+			clear_opt(sbi, INLINE_DATA);
+			break;
+		default:
+			f2fs_msg(sb, KERN_ERR,
+				"Unrecognized mount option \"%s\" or missing value",
+				p);
+			return -EINVAL;
+		}
+	}
+	return 0;
+}
+
+static struct inode *f2fs_alloc_inode(struct super_block *sb)
+{
+	struct f2fs_inode_info *fi;
+
+	fi = kmem_cache_alloc(f2fs_inode_cachep, GFP_F2FS_ZERO);
+	if (!fi)
+		return NULL;
+
+	init_once((void *) fi);
+
+	/* Initialize f2fs-specific inode info */
+	fi->vfs_inode.i_version = 1;
+	atomic_set(&fi->dirty_pages, 0);
+	fi->i_current_depth = 1;
+	fi->i_advise = 0;
+	rwlock_init(&fi->ext_lock);
+	init_rwsem(&fi->i_sem);
+	INIT_RADIX_TREE(&fi->inmem_root, GFP_NOFS);
+	INIT_LIST_HEAD(&fi->inmem_pages);
+	mutex_init(&fi->inmem_lock);
+
+	set_inode_flag(fi, FI_NEW_INODE);
+
+	if (test_opt(F2FS_SB(sb), INLINE_XATTR))
+		set_inode_flag(fi, FI_INLINE_XATTR);
+
+	/* Will be used by directory only */
+	fi->i_dir_level = F2FS_SB(sb)->dir_level;
+
+	return &fi->vfs_inode;
+}
+
+static int f2fs_drop_inode(struct inode *inode)
+{
+	/*
+	 * This is to avoid a deadlock condition like below.
+	 * writeback_single_inode(inode)
+	 *  - f2fs_write_data_page
+	 *    - f2fs_gc -> iput -> evict
+	 *       - inode_wait_for_writeback(inode)
+	 */
+	if (!inode_unhashed(inode) && inode->i_state & I_SYNC)
+		return 0;
+	return generic_drop_inode(inode);
+}
+
+/*
+ * f2fs_dirty_inode() is called from __mark_inode_dirty()
+ *
+ * We should call set_dirty_inode to write the dirty inode through write_inode.
+ */
+static void f2fs_dirty_inode(struct inode *inode, int flags)
+{
+	set_inode_flag(F2FS_I(inode), FI_DIRTY_INODE);
+}
+
+static void f2fs_i_callback(struct rcu_head *head)
+{
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	kmem_cache_free(f2fs_inode_cachep, F2FS_I(inode));
+}
+
+static void f2fs_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, f2fs_i_callback);
+}
+
+static void f2fs_put_super(struct super_block *sb)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+
+	if (sbi->s_proc) {
+		remove_proc_entry("segment_info", sbi->s_proc);
+		remove_proc_entry(sb->s_id, f2fs_proc_root);
+	}
+	kobject_del(&sbi->s_kobj);
+
+	f2fs_destroy_stats(sbi);
+	stop_gc_thread(sbi);
+
+	/*
+	 * We don't need to do checkpoint when superblock is clean.
+	 * But, the previous checkpoint was not done by umount, it needs to do
+	 * clean checkpoint again.
+	 */
+	if (is_sbi_flag_set(sbi, SBI_IS_DIRTY) ||
+			!is_set_ckpt_flags(F2FS_CKPT(sbi), CP_UMOUNT_FLAG)) {
+		struct cp_control cpc = {
+			.reason = CP_UMOUNT,
+		};
+		write_checkpoint(sbi, &cpc);
+	}
+
+	/*
+	 * normally superblock is clean, so we need to release this.
+	 * In addition, EIO will skip do checkpoint, we need this as well.
+	 */
+	release_dirty_inode(sbi);
+	release_discard_addrs(sbi);
+
+	iput(sbi->node_inode);
+	iput(sbi->meta_inode);
+
+	/* destroy f2fs internal modules */
+	destroy_node_manager(sbi);
+	destroy_segment_manager(sbi);
+
+	kfree(sbi->ckpt);
+	kobject_put(&sbi->s_kobj);
+	wait_for_completion(&sbi->s_kobj_unregister);
+
+	sb->s_fs_info = NULL;
+	brelse(sbi->raw_super_buf);
+	kfree(sbi);
+}
+
+int f2fs_sync_fs(struct super_block *sb, int sync)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+
+	trace_f2fs_sync_fs(sb, sync);
+
+	if (sync) {
+		struct cp_control cpc;
+
+		cpc.reason = __get_cp_reason(sbi);
+
+		mutex_lock(&sbi->gc_mutex);
+		write_checkpoint(sbi, &cpc);
+		mutex_unlock(&sbi->gc_mutex);
+	} else {
+		f2fs_balance_fs(sbi);
+	}
+	f2fs_trace_ios(NULL, NULL, 1);
+
+	return 0;
+}
+
+static int f2fs_freeze(struct super_block *sb)
+{
+	int err;
+
+	if (f2fs_readonly(sb))
+		return 0;
+
+	err = f2fs_sync_fs(sb, 1);
+	return err;
+}
+
+static int f2fs_unfreeze(struct super_block *sb)
+{
+	return 0;
+}
+
+static int f2fs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+	struct super_block *sb = dentry->d_sb;
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
+	block_t total_count, user_block_count, start_count, ovp_count;
+
+	total_count = le64_to_cpu(sbi->raw_super->block_count);
+	user_block_count = sbi->user_block_count;
+	start_count = le32_to_cpu(sbi->raw_super->segment0_blkaddr);
+	ovp_count = SM_I(sbi)->ovp_segments << sbi->log_blocks_per_seg;
+	buf->f_type = F2FS_SUPER_MAGIC;
+	buf->f_bsize = sbi->blocksize;
+
+	buf->f_blocks = total_count - start_count;
+	buf->f_bfree = buf->f_blocks - valid_user_blocks(sbi) - ovp_count;
+	buf->f_bavail = user_block_count - valid_user_blocks(sbi);
+
+	buf->f_files = sbi->total_node_count - F2FS_RESERVED_NODE_NUM;
+	buf->f_ffree = buf->f_files - valid_inode_count(sbi);
+
+	buf->f_namelen = F2FS_NAME_LEN;
+	buf->f_fsid.val[0] = (u32)id;
+	buf->f_fsid.val[1] = (u32)(id >> 32);
+
+	return 0;
+}
+
+static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(root->d_sb);
+
+	if (!f2fs_readonly(sbi->sb) && test_opt(sbi, BG_GC))
+		seq_printf(seq, ",background_gc=%s", "on");
+	else
+		seq_printf(seq, ",background_gc=%s", "off");
+	if (test_opt(sbi, DISABLE_ROLL_FORWARD))
+		seq_puts(seq, ",disable_roll_forward");
+	if (test_opt(sbi, DISCARD))
+		seq_puts(seq, ",discard");
+	if (test_opt(sbi, NOHEAP))
+		seq_puts(seq, ",no_heap_alloc");
+#ifdef CONFIG_F2FS_FS_XATTR
+	if (test_opt(sbi, XATTR_USER))
+		seq_puts(seq, ",user_xattr");
+	else
+		seq_puts(seq, ",nouser_xattr");
+	if (test_opt(sbi, INLINE_XATTR))
+		seq_puts(seq, ",inline_xattr");
+#endif
+#ifdef CONFIG_F2FS_FS_POSIX_ACL
+	if (test_opt(sbi, POSIX_ACL))
+		seq_puts(seq, ",acl");
+	else
+		seq_puts(seq, ",noacl");
+#endif
+	if (test_opt(sbi, DISABLE_EXT_IDENTIFY))
+		seq_puts(seq, ",disable_ext_identify");
+	if (test_opt(sbi, INLINE_DATA))
+		seq_puts(seq, ",inline_data");
+	else
+		seq_puts(seq, ",noinline_data");
+	if (test_opt(sbi, INLINE_DENTRY))
+		seq_puts(seq, ",inline_dentry");
+	if (!f2fs_readonly(sbi->sb) && test_opt(sbi, FLUSH_MERGE))
+		seq_puts(seq, ",flush_merge");
+	if (test_opt(sbi, NOBARRIER))
+		seq_puts(seq, ",nobarrier");
+	if (test_opt(sbi, FASTBOOT))
+		seq_puts(seq, ",fastboot");
+	if (test_opt(sbi, EXTENT_CACHE))
+		seq_puts(seq, ",extent_cache");
+	seq_printf(seq, ",active_logs=%u", sbi->active_logs);
+
+	return 0;
+}
+
+static int segment_info_seq_show(struct seq_file *seq, void *offset)
+{
+	struct super_block *sb = seq->private;
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+	unsigned int total_segs =
+			le32_to_cpu(sbi->raw_super->segment_count_main);
+	int i;
+
+	seq_puts(seq, "format: segment_type|valid_blocks\n"
+		"segment_type(0:HD, 1:WD, 2:CD, 3:HN, 4:WN, 5:CN)\n");
+
+	for (i = 0; i < total_segs; i++) {
+		struct seg_entry *se = get_seg_entry(sbi, i);
+
+		if ((i % 10) == 0)
+			seq_printf(seq, "%-5d", i);
+		seq_printf(seq, "%d|%-3u", se->type,
+					get_valid_blocks(sbi, i, 1));
+		if ((i % 10) == 9 || i == (total_segs - 1))
+			seq_putc(seq, '\n');
+		else
+			seq_putc(seq, ' ');
+	}
+
+	return 0;
+}
+
+static int segment_info_open_fs(struct inode *inode, struct file *file)
+{
+	return single_open(file, segment_info_seq_show, PDE_DATA(inode));
+}
+
+static const struct file_operations f2fs_seq_segment_info_fops = {
+	.owner = THIS_MODULE,
+	.open = segment_info_open_fs,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+static int f2fs_remount(struct super_block *sb, int *flags, char *data)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+	struct f2fs_mount_info org_mount_opt;
+	int err, active_logs;
+	bool need_restart_gc = false;
+	bool need_stop_gc = false;
+
+	sync_filesystem(sb);
+
+	/*
+	 * Save the old mount options in case we
+	 * need to restore them.
+	 */
+	org_mount_opt = sbi->mount_opt;
+	active_logs = sbi->active_logs;
+
+	sbi->mount_opt.opt = 0;
+	sbi->active_logs = NR_CURSEG_TYPE;
+
+	/* parse mount options */
+	err = parse_options(sb, data);
+	if (err)
+		goto restore_opts;
+
+	/*
+	 * Previous and new state of filesystem is RO,
+	 * so skip checking GC and FLUSH_MERGE conditions.
+	 */
+	if (f2fs_readonly(sb) && (*flags & MS_RDONLY))
+		goto skip;
+
+	/*
+	 * We stop the GC thread if FS is mounted as RO
+	 * or if background_gc = off is passed in mount
+	 * option. Also sync the filesystem.
+	 */
+	if ((*flags & MS_RDONLY) || !test_opt(sbi, BG_GC)) {
+		if (sbi->gc_thread) {
+			stop_gc_thread(sbi);
+			f2fs_sync_fs(sb, 1);
+			need_restart_gc = true;
+		}
+	} else if (!sbi->gc_thread) {
+		err = start_gc_thread(sbi);
+		if (err)
+			goto restore_opts;
+		need_stop_gc = true;
+	}
+
+	/*
+	 * We stop issue flush thread if FS is mounted as RO
+	 * or if flush_merge is not passed in mount option.
+	 */
+	if ((*flags & MS_RDONLY) || !test_opt(sbi, FLUSH_MERGE)) {
+		destroy_flush_cmd_control(sbi);
+	} else if (!SM_I(sbi)->cmd_control_info) {
+		err = create_flush_cmd_control(sbi);
+		if (err)
+			goto restore_gc;
+	}
+skip:
+	/* Update the POSIXACL Flag */
+	 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
+		(test_opt(sbi, POSIX_ACL) ? MS_POSIXACL : 0);
+	return 0;
+restore_gc:
+	if (need_restart_gc) {
+		if (start_gc_thread(sbi))
+			f2fs_msg(sbi->sb, KERN_WARNING,
+				"background gc thread has stopped");
+	} else if (need_stop_gc) {
+		stop_gc_thread(sbi);
+	}
+restore_opts:
+	sbi->mount_opt = org_mount_opt;
+	sbi->active_logs = active_logs;
+	return err;
+}
+
+static struct super_operations f2fs_sops = {
+	.alloc_inode	= f2fs_alloc_inode,
+	.drop_inode	= f2fs_drop_inode,
+	.destroy_inode	= f2fs_destroy_inode,
+	.write_inode	= f2fs_write_inode,
+	.dirty_inode	= f2fs_dirty_inode,
+	.show_options	= f2fs_show_options,
+	.evict_inode	= f2fs_evict_inode,
+	.put_super	= f2fs_put_super,
+	.sync_fs	= f2fs_sync_fs,
+	.freeze_fs	= f2fs_freeze,
+	.unfreeze_fs	= f2fs_unfreeze,
+	.statfs		= f2fs_statfs,
+	.remount_fs	= f2fs_remount,
+};
+
+static struct inode *f2fs_nfs_get_inode(struct super_block *sb,
+		u64 ino, u32 generation)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+	struct inode *inode;
+
+	if (check_nid_range(sbi, ino))
+		return ERR_PTR(-ESTALE);
+
+	/*
+	 * f2fs_iget isn't quite right if the inode is currently unallocated!
+	 * However f2fs_iget currently does appropriate checks to handle stale
+	 * inodes so everything is OK.
+	 */
+	inode = f2fs_iget(sb, ino);
+	if (IS_ERR(inode))
+		return ERR_CAST(inode);
+	if (unlikely(generation && inode->i_generation != generation)) {
+		/* we didn't find the right inode.. */
+		iput(inode);
+		return ERR_PTR(-ESTALE);
+	}
+	return inode;
+}
+
+static struct dentry *f2fs_fh_to_dentry(struct super_block *sb, struct fid *fid,
+		int fh_len, int fh_type)
+{
+	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
+				    f2fs_nfs_get_inode);
+}
+
+static struct dentry *f2fs_fh_to_parent(struct super_block *sb, struct fid *fid,
+		int fh_len, int fh_type)
+{
+	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
+				    f2fs_nfs_get_inode);
+}
+
+static const struct export_operations f2fs_export_ops = {
+	.fh_to_dentry = f2fs_fh_to_dentry,
+	.fh_to_parent = f2fs_fh_to_parent,
+	.get_parent = f2fs_get_parent,
+};
+
+static loff_t max_file_size(unsigned bits)
+{
+	loff_t result = (DEF_ADDRS_PER_INODE - F2FS_INLINE_XATTR_ADDRS);
+	loff_t leaf_count = ADDRS_PER_BLOCK;
+
+	/* two direct node blocks */
+	result += (leaf_count * 2);
+
+	/* two indirect node blocks */
+	leaf_count *= NIDS_PER_BLOCK;
+	result += (leaf_count * 2);
+
+	/* one double indirect node block */
+	leaf_count *= NIDS_PER_BLOCK;
+	result += leaf_count;
+
+	result <<= bits;
+	return result;
+}
+
+static int sanity_check_raw_super(struct super_block *sb,
+			struct f2fs_super_block *raw_super)
+{
+	unsigned int blocksize;
+
+	if (F2FS_SUPER_MAGIC != le32_to_cpu(raw_super->magic)) {
+		f2fs_msg(sb, KERN_INFO,
+			"Magic Mismatch, valid(0x%x) - read(0x%x)",
+			F2FS_SUPER_MAGIC, le32_to_cpu(raw_super->magic));
+		return 1;
+	}
+
+	/* Currently, support only 4KB page cache size */
+	if (F2FS_BLKSIZE != PAGE_CACHE_SIZE) {
+		f2fs_msg(sb, KERN_INFO,
+			"Invalid page_cache_size (%lu), supports only 4KB\n",
+			PAGE_CACHE_SIZE);
+		return 1;
+	}
+
+	/* Currently, support only 4KB block size */
+	blocksize = 1 << le32_to_cpu(raw_super->log_blocksize);
+	if (blocksize != F2FS_BLKSIZE) {
+		f2fs_msg(sb, KERN_INFO,
+			"Invalid blocksize (%u), supports only 4KB\n",
+			blocksize);
+		return 1;
+	}
+
+	/* Currently, support 512/1024/2048/4096 bytes sector size */
+	if (le32_to_cpu(raw_super->log_sectorsize) >
+				F2FS_MAX_LOG_SECTOR_SIZE ||
+		le32_to_cpu(raw_super->log_sectorsize) <
+				F2FS_MIN_LOG_SECTOR_SIZE) {
+		f2fs_msg(sb, KERN_INFO, "Invalid log sectorsize (%u)",
+			le32_to_cpu(raw_super->log_sectorsize));
+		return 1;
+	}
+	if (le32_to_cpu(raw_super->log_sectors_per_block) +
+		le32_to_cpu(raw_super->log_sectorsize) !=
+			F2FS_MAX_LOG_SECTOR_SIZE) {
+		f2fs_msg(sb, KERN_INFO,
+			"Invalid log sectors per block(%u) log sectorsize(%u)",
+			le32_to_cpu(raw_super->log_sectors_per_block),
+			le32_to_cpu(raw_super->log_sectorsize));
+		return 1;
+	}
+	return 0;
+}
+
+static int sanity_check_ckpt(struct f2fs_sb_info *sbi)
+{
+	unsigned int total, fsmeta;
+	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
+	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
+
+	total = le32_to_cpu(raw_super->segment_count);
+	fsmeta = le32_to_cpu(raw_super->segment_count_ckpt);
+	fsmeta += le32_to_cpu(raw_super->segment_count_sit);
+	fsmeta += le32_to_cpu(raw_super->segment_count_nat);
+	fsmeta += le32_to_cpu(ckpt->rsvd_segment_count);
+	fsmeta += le32_to_cpu(raw_super->segment_count_ssa);
+
+	if (unlikely(fsmeta >= total))
+		return 1;
+
+	if (unlikely(f2fs_cp_error(sbi))) {
+		f2fs_msg(sbi->sb, KERN_ERR, "A bug case: need to run fsck");
+		return 1;
+	}
+	return 0;
+}
+
+static void init_sb_info(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_super_block *raw_super = sbi->raw_super;
+	int i;
+
+	sbi->log_sectors_per_block =
+		le32_to_cpu(raw_super->log_sectors_per_block);
+	sbi->log_blocksize = le32_to_cpu(raw_super->log_blocksize);
+	sbi->blocksize = 1 << sbi->log_blocksize;
+	sbi->log_blocks_per_seg = le32_to_cpu(raw_super->log_blocks_per_seg);
+	sbi->blocks_per_seg = 1 << sbi->log_blocks_per_seg;
+	sbi->segs_per_sec = le32_to_cpu(raw_super->segs_per_sec);
+	sbi->secs_per_zone = le32_to_cpu(raw_super->secs_per_zone);
+	sbi->total_sections = le32_to_cpu(raw_super->section_count);
+	sbi->total_node_count =
+		(le32_to_cpu(raw_super->segment_count_nat) / 2)
+			* sbi->blocks_per_seg * NAT_ENTRY_PER_BLOCK;
+	sbi->root_ino_num = le32_to_cpu(raw_super->root_ino);
+	sbi->node_ino_num = le32_to_cpu(raw_super->node_ino);
+	sbi->meta_ino_num = le32_to_cpu(raw_super->meta_ino);
+	sbi->cur_victim_sec = NULL_SECNO;
+	sbi->max_victim_search = DEF_MAX_VICTIM_SEARCH;
+
+	for (i = 0; i < NR_COUNT_TYPE; i++)
+		atomic_set(&sbi->nr_pages[i], 0);
+
+	sbi->dir_level = DEF_DIR_LEVEL;
+	clear_sbi_flag(sbi, SBI_NEED_FSCK);
+}
+
+/*
+ * Read f2fs raw super block.
+ * Because we have two copies of super block, so read the first one at first,
+ * if the first one is invalid, move to read the second one.
+ */
+static int read_raw_super_block(struct super_block *sb,
+			struct f2fs_super_block **raw_super,
+			struct buffer_head **raw_super_buf)
+{
+	int block = 0;
+
+retry:
+	*raw_super_buf = sb_bread(sb, block);
+	if (!*raw_super_buf) {
+		f2fs_msg(sb, KERN_ERR, "Unable to read %dth superblock",
+				block + 1);
+		if (block == 0) {
+			block++;
+			goto retry;
+		} else {
+			return -EIO;
+		}
+	}
+
+	*raw_super = (struct f2fs_super_block *)
+		((char *)(*raw_super_buf)->b_data + F2FS_SUPER_OFFSET);
+
+	/* sanity checking of raw super */
+	if (sanity_check_raw_super(sb, *raw_super)) {
+		brelse(*raw_super_buf);
+		f2fs_msg(sb, KERN_ERR,
+			"Can't find valid F2FS filesystem in %dth superblock",
+								block + 1);
+		if (block == 0) {
+			block++;
+			goto retry;
+		} else {
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
+{
+	struct f2fs_sb_info *sbi;
+	struct f2fs_super_block *raw_super = NULL;
+	struct buffer_head *raw_super_buf;
+	struct inode *root;
+	long err = -EINVAL;
+	bool retry = true, need_fsck = false;
+	char *options = NULL;
+	int i;
+
+try_onemore:
+	/* allocate memory for f2fs-specific super block info */
+	sbi = kzalloc(sizeof(struct f2fs_sb_info), GFP_KERNEL);
+	if (!sbi)
+		return -ENOMEM;
+
+	/* set a block size */
+	if (unlikely(!sb_set_blocksize(sb, F2FS_BLKSIZE))) {
+		f2fs_msg(sb, KERN_ERR, "unable to set blocksize");
+		goto free_sbi;
+	}
+
+	err = read_raw_super_block(sb, &raw_super, &raw_super_buf);
+	if (err)
+		goto free_sbi;
+
+	sb->s_fs_info = sbi;
+	/* init some FS parameters */
+	sbi->active_logs = NR_CURSEG_TYPE;
+
+	set_opt(sbi, BG_GC);
+	set_opt(sbi, INLINE_DATA);
+
+#ifdef CONFIG_F2FS_FS_XATTR
+	set_opt(sbi, XATTR_USER);
+#endif
+#ifdef CONFIG_F2FS_FS_POSIX_ACL
+	set_opt(sbi, POSIX_ACL);
+#endif
+	/* parse mount options */
+	options = kstrdup((const char *)data, GFP_KERNEL);
+	if (data && !options) {
+		err = -ENOMEM;
+		goto free_sb_buf;
+	}
+
+	err = parse_options(sb, options);
+	if (err)
+		goto free_options;
+
+	sb->s_maxbytes = max_file_size(le32_to_cpu(raw_super->log_blocksize));
+	sb->s_max_links = F2FS_LINK_MAX;
+	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
+
+	sb->s_op = &f2fs_sops;
+	sb->s_xattr = f2fs_xattr_handlers;
+	sb->s_export_op = &f2fs_export_ops;
+	sb->s_magic = F2FS_SUPER_MAGIC;
+	sb->s_time_gran = 1;
+	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
+		(test_opt(sbi, POSIX_ACL) ? MS_POSIXACL : 0);
+	memcpy(sb->s_uuid, raw_super->uuid, sizeof(raw_super->uuid));
+
+	/* init f2fs-specific super block info */
+	sbi->sb = sb;
+	sbi->raw_super = raw_super;
+	sbi->raw_super_buf = raw_super_buf;
+	mutex_init(&sbi->gc_mutex);
+	mutex_init(&sbi->writepages);
+	mutex_init(&sbi->cp_mutex);
+	init_rwsem(&sbi->node_write);
+	clear_sbi_flag(sbi, SBI_POR_DOING);
+	spin_lock_init(&sbi->stat_lock);
+
+	init_rwsem(&sbi->read_io.io_rwsem);
+	sbi->read_io.sbi = sbi;
+	sbi->read_io.bio = NULL;
+	for (i = 0; i < NR_PAGE_TYPE; i++) {
+		init_rwsem(&sbi->write_io[i].io_rwsem);
+		sbi->write_io[i].sbi = sbi;
+		sbi->write_io[i].bio = NULL;
+	}
+
+	init_rwsem(&sbi->cp_rwsem);
+	init_waitqueue_head(&sbi->cp_wait);
+	init_sb_info(sbi);
+
+	/* get an inode for meta space */
+	sbi->meta_inode = f2fs_iget(sb, F2FS_META_INO(sbi));
+	if (IS_ERR(sbi->meta_inode)) {
+		f2fs_msg(sb, KERN_ERR, "Failed to read F2FS meta data inode");
+		err = PTR_ERR(sbi->meta_inode);
+		goto free_options;
+	}
+
+	err = get_valid_checkpoint(sbi);
+	if (err) {
+		f2fs_msg(sb, KERN_ERR, "Failed to get valid F2FS checkpoint");
+		goto free_meta_inode;
+	}
+
+	/* sanity checking of checkpoint */
+	err = -EINVAL;
+	if (sanity_check_ckpt(sbi)) {
+		f2fs_msg(sb, KERN_ERR, "Invalid F2FS checkpoint");
+		goto free_cp;
+	}
+
+	sbi->total_valid_node_count =
+				le32_to_cpu(sbi->ckpt->valid_node_count);
+	sbi->total_valid_inode_count =
+				le32_to_cpu(sbi->ckpt->valid_inode_count);
+	sbi->user_block_count = le64_to_cpu(sbi->ckpt->user_block_count);
+	sbi->total_valid_block_count =
+				le64_to_cpu(sbi->ckpt->valid_block_count);
+	sbi->last_valid_block_count = sbi->total_valid_block_count;
+	sbi->alloc_valid_block_count = 0;
+	INIT_LIST_HEAD(&sbi->dir_inode_list);
+	spin_lock_init(&sbi->dir_inode_lock);
+
+	init_extent_cache_info(sbi);
+
+	init_ino_entry_info(sbi);
+
+	/* setup f2fs internal modules */
+	err = build_segment_manager(sbi);
+	if (err) {
+		f2fs_msg(sb, KERN_ERR,
+			"Failed to initialize F2FS segment manager");
+		goto free_sm;
+	}
+	err = build_node_manager(sbi);
+	if (err) {
+		f2fs_msg(sb, KERN_ERR,
+			"Failed to initialize F2FS node manager");
+		goto free_nm;
+	}
+
+	build_gc_manager(sbi);
+
+	/* get an inode for node space */
+	sbi->node_inode = f2fs_iget(sb, F2FS_NODE_INO(sbi));
+	if (IS_ERR(sbi->node_inode)) {
+		f2fs_msg(sb, KERN_ERR, "Failed to read node inode");
+		err = PTR_ERR(sbi->node_inode);
+		goto free_nm;
+	}
+
+	/* if there are nt orphan nodes free them */
+	recover_orphan_inodes(sbi);
+
+	/* read root inode and dentry */
+	root = f2fs_iget(sb, F2FS_ROOT_INO(sbi));
+	if (IS_ERR(root)) {
+		f2fs_msg(sb, KERN_ERR, "Failed to read root inode");
+		err = PTR_ERR(root);
+		goto free_node_inode;
+	}
+	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
+		iput(root);
+		err = -EINVAL;
+		goto free_node_inode;
+	}
+
+	sb->s_root = d_make_root(root); /* allocate root dentry */
+	if (!sb->s_root) {
+		err = -ENOMEM;
+		goto free_root_inode;
+	}
+
+	err = f2fs_build_stats(sbi);
+	if (err)
+		goto free_root_inode;
+
+	if (f2fs_proc_root)
+		sbi->s_proc = proc_mkdir(sb->s_id, f2fs_proc_root);
+
+	if (sbi->s_proc)
+		proc_create_data("segment_info", S_IRUGO, sbi->s_proc,
+				 &f2fs_seq_segment_info_fops, sb);
+
+	if (test_opt(sbi, DISCARD)) {
+		struct request_queue *q = bdev_get_queue(sb->s_bdev);
+		if (!blk_queue_discard(q))
+			f2fs_msg(sb, KERN_WARNING,
+					"mounting with \"discard\" option, but "
+					"the device does not support discard");
+	}
+
+	sbi->s_kobj.kset = f2fs_kset;
+	init_completion(&sbi->s_kobj_unregister);
+	err = kobject_init_and_add(&sbi->s_kobj, &f2fs_ktype, NULL,
+							"%s", sb->s_id);
+	if (err)
+		goto free_proc;
+
+	/* recover fsynced data */
+	if (!test_opt(sbi, DISABLE_ROLL_FORWARD)) {
+		/*
+		 * mount should be failed, when device has readonly mode, and
+		 * previous checkpoint was not done by clean system shutdown.
+		 */
+		if (bdev_read_only(sb->s_bdev) &&
+				!is_set_ckpt_flags(sbi->ckpt, CP_UMOUNT_FLAG)) {
+			err = -EROFS;
+			goto free_kobj;
+		}
+
+		if (need_fsck)
+			set_sbi_flag(sbi, SBI_NEED_FSCK);
+
+		err = recover_fsync_data(sbi);
+		if (err) {
+			need_fsck = true;
+			f2fs_msg(sb, KERN_ERR,
+				"Cannot recover all fsync data errno=%ld", err);
+			goto free_kobj;
+		}
+	}
+
+	/*
+	 * If filesystem is not mounted as read-only then
+	 * do start the gc_thread.
+	 */
+	if (test_opt(sbi, BG_GC) && !f2fs_readonly(sb)) {
+		/* After POR, we can run background GC thread.*/
+		err = start_gc_thread(sbi);
+		if (err)
+			goto free_kobj;
+	}
+	kfree(options);
+	return 0;
+
+free_kobj:
+	kobject_del(&sbi->s_kobj);
+free_proc:
+	if (sbi->s_proc) {
+		remove_proc_entry("segment_info", sbi->s_proc);
+		remove_proc_entry(sb->s_id, f2fs_proc_root);
+	}
+	f2fs_destroy_stats(sbi);
+free_root_inode:
+	dput(sb->s_root);
+	sb->s_root = NULL;
+free_node_inode:
+	iput(sbi->node_inode);
+free_nm:
+	destroy_node_manager(sbi);
+free_sm:
+	destroy_segment_manager(sbi);
+free_cp:
+	kfree(sbi->ckpt);
+free_meta_inode:
+	make_bad_inode(sbi->meta_inode);
+	iput(sbi->meta_inode);
+free_options:
+	kfree(options);
+free_sb_buf:
+	brelse(raw_super_buf);
+free_sbi:
+	kfree(sbi);
+
+	/* give only one another chance */
+	if (retry) {
+		retry = false;
+		shrink_dcache_sb(sb);
+		goto try_onemore;
+	}
+	return err;
+}
+
+static struct dentry *f2fs_mount(struct file_system_type *fs_type, int flags,
+			const char *dev_name, void *data)
+{
+	return mount_bdev(fs_type, flags, dev_name, data, f2fs_fill_super);
+}
+
+static void kill_f2fs_super(struct super_block *sb)
+{
+	if (sb->s_root)
+		set_sbi_flag(F2FS_SB(sb), SBI_IS_CLOSE);
+	kill_block_super(sb);
+}
+
+static struct file_system_type f2fs_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "f2fs",
+	.mount		= f2fs_mount,
+	.kill_sb	= kill_f2fs_super,
+	.fs_flags	= FS_REQUIRES_DEV,
+};
+MODULE_ALIAS_FS("f2fs");
+
+static int __init init_inodecache(void)
+{
+	f2fs_inode_cachep = f2fs_kmem_cache_create("f2fs_inode_cache",
+			sizeof(struct f2fs_inode_info));
+	if (!f2fs_inode_cachep)
+		return -ENOMEM;
+	return 0;
+}
+
+static void destroy_inodecache(void)
+{
+	/*
+	 * Make sure all delayed rcu free inodes are flushed before we
+	 * destroy cache.
+	 */
+	rcu_barrier();
+	kmem_cache_destroy(f2fs_inode_cachep);
+}
+
+static int __init init_f2fs_fs(void)
+{
+	int err;
+
+	f2fs_build_trace_ios();
+
+	err = init_inodecache();
+	if (err)
+		goto fail;
+	err = create_node_manager_caches();
+	if (err)
+		goto free_inodecache;
+	err = create_segment_manager_caches();
+	if (err)
+		goto free_node_manager_caches;
+	err = create_checkpoint_caches();
+	if (err)
+		goto free_segment_manager_caches;
+	err = create_extent_cache();
+	if (err)
+		goto free_checkpoint_caches;
+	f2fs_kset = kset_create_and_add("f2fs", NULL, fs_kobj);
+	if (!f2fs_kset) {
+		err = -ENOMEM;
+		goto free_extent_cache;
+	}
+	err = register_filesystem(&f2fs_fs_type);
+	if (err)
+		goto free_kset;
+	f2fs_create_root_stats();
+	f2fs_proc_root = proc_mkdir("fs/f2fs", NULL);
+	return 0;
+
+free_kset:
+	kset_unregister(f2fs_kset);
+free_extent_cache:
+	destroy_extent_cache();
+free_checkpoint_caches:
+	destroy_checkpoint_caches();
+free_segment_manager_caches:
+	destroy_segment_manager_caches();
+free_node_manager_caches:
+	destroy_node_manager_caches();
+free_inodecache:
+	destroy_inodecache();
+fail:
+	return err;
+}
+
+static void __exit exit_f2fs_fs(void)
+{
+	remove_proc_entry("fs/f2fs", NULL);
+	f2fs_destroy_root_stats();
+	unregister_filesystem(&f2fs_fs_type);
+	destroy_extent_cache();
+	destroy_checkpoint_caches();
+	destroy_segment_manager_caches();
+	destroy_node_manager_caches();
+	destroy_inodecache();
+	kset_unregister(f2fs_kset);
+	f2fs_destroy_trace_ios();
+}
+
+module_init(init_f2fs_fs)
+module_exit(exit_f2fs_fs)
+
+MODULE_AUTHOR("Samsung Electronics's Praesto Team");
+MODULE_DESCRIPTION("Flash Friendly File System");
+MODULE_LICENSE("GPL");