/*
 * 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);
}

/*
 * Called at the last iput() if i_nlink is zero
 */
void f2fs_evict_inode(struct inode *inode)
{
	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
	struct f2fs_inode_info *fi = F2FS_I(inode);
	nid_t xnid = fi->i_xattr_nid;
	int err = 0;

	/* some remained atomic pages should discarded */
	if (f2fs_is_atomic_file(inode))
		commit_inmem_pages(inode, true);

	trace_f2fs_evict_inode(inode);
	truncate_inode_pages(&inode->i_data, 0);

	if (inode->i_ino == F2FS_NODE_INO(sbi) ||
			inode->i_ino == F2FS_META_INO(sbi))
		goto out_clear;

	f2fs_bug_on(sbi, get_dirty_pages(inode));
	remove_dirty_dir_inode(inode);

	f2fs_destroy_extent_tree(inode);

	if (inode->i_nlink || is_bad_inode(inode))
		goto no_delete;

	set_inode_flag(fi, FI_NO_ALLOC);
	i_size_write(inode, 0);

	if (F2FS_HAS_BLOCKS(inode))
		err = f2fs_truncate(inode, true);

	if (!err) {
		f2fs_lock_op(sbi);
		err = remove_inode_page(inode);
		f2fs_unlock_op(sbi);
	}

no_delete:
	stat_dec_inline_xattr(inode);
	stat_dec_inline_dir(inode);
	stat_dec_inline_inode(inode);

	invalidate_mapping_pages(NODE_MAPPING(sbi), inode->i_ino, inode->i_ino);
	if (xnid)
		invalidate_mapping_pages(NODE_MAPPING(sbi), xnid, xnid);
	if (is_inode_flag_set(fi, FI_APPEND_WRITE))
		add_dirty_inode(sbi, inode->i_ino, APPEND_INO);
	if (is_inode_flag_set(fi, FI_UPDATE_WRITE))
		add_dirty_inode(sbi, inode->i_ino, UPDATE_INO);
	if (is_inode_flag_set(fi, FI_FREE_NID)) {
		if (err && err != -ENOENT)
			alloc_nid_done(sbi, inode->i_ino);
		else
			alloc_nid_failed(sbi, inode->i_ino);
		clear_inode_flag(fi, FI_FREE_NID);
	}

	if (err && err != -ENOENT) {
		if (!exist_written_data(sbi, inode->i_ino, ORPHAN_INO)) {
			/*
			 * get here because we failed to release resource
			 * of inode previously, reminder our user to run fsck
			 * for fixing.
			 */
			set_sbi_flag(sbi, SBI_NEED_FSCK);
			f2fs_msg(sbi->sb, KERN_WARNING,
				"inode (ino:%lu) resource leak, run fsck "
				"to fix this issue!", inode->i_ino);
		}
	}
out_clear:
#ifdef CONFIG_F2FS_FS_ENCRYPTION
	if (fi->i_crypt_info)
		f2fs_free_encryption_info(inode, fi->i_crypt_info);
#endif
	end_writeback(inode);
}

int f2fs_convert_inline_page(struct dnode_of_data *dn, struct page *page)
{
	void *src_addr, *dst_addr;
	struct f2fs_io_info fio = {
		.type = DATA,
		.rw = WRITE_SYNC | REQ_PRIO,
	};
	int dirty, err;

	f2fs_bug_on(F2FS_I_SB(dn->inode), page->index);

	if (!f2fs_exist_data(dn->inode))
		goto clear_out;

	err = f2fs_reserve_block(dn, 0);
	if (err)
		return err;

	f2fs_wait_on_page_writeback(page, DATA);

	if (PageUptodate(page))
		goto no_update;

	zero_user_segment(page, MAX_INLINE_DATA, PAGE_CACHE_SIZE);

	/* Copy the whole inline data block */
	src_addr = inline_data_addr(dn->inode_page);
	dst_addr = kmap_atomic(page);
	memcpy(dst_addr, src_addr, MAX_INLINE_DATA);
	flush_dcache_page(page);
	kunmap_atomic(dst_addr);
	SetPageUptodate(page);
no_update:
	/* clear dirty state */
	dirty = clear_page_dirty_for_io(page);

	/* write data page to try to make data consistent */
	set_page_writeback(page);
	fio.blk_addr = dn->data_blkaddr;
	write_data_page(page, dn, &fio);
	update_extent_cache(dn);
	f2fs_wait_on_page_writeback(page, DATA);
	if (dirty)
		inode_dec_dirty_pages(dn->inode);

	/* this converted inline_data should be recovered. */
	set_inode_flag(F2FS_I(dn->inode), FI_APPEND_WRITE);

	/* clear inline data and flag after data writeback */
	truncate_inline_data(dn->inode_page);
clear_out:
	stat_dec_inline_inode(dn->inode);
	f2fs_clear_inline_inode(dn->inode);
	sync_inode_page(dn);
	f2fs_put_dnode(dn);
	return 0;
}

int f2fs_convert_inline_inode(struct inode *inode)
{
	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
	struct dnode_of_data dn;
	struct page *ipage, *page;
	int err = 0;

	page = grab_cache_page(inode->i_mapping, 0);
	if (!page)
		return -ENOMEM;

	f2fs_lock_op(sbi);

	ipage = get_node_page(sbi, inode->i_ino);
	if (IS_ERR(ipage)) {
		err = PTR_ERR(ipage);
		goto out;
	}

	set_new_dnode(&dn, inode, ipage, ipage, 0);

	if (f2fs_has_inline_data(inode))
		err = f2fs_convert_inline_page(&dn, page);

	f2fs_put_dnode(&dn);
out:
	f2fs_unlock_op(sbi);

	f2fs_put_page(page, 1);
	return err;
}

int f2fs_write_inline_data(struct inode *inode, struct page *page)
{
	void *src_addr, *dst_addr;
	struct dnode_of_data dn;
	int err;

	set_new_dnode(&dn, inode, NULL, NULL, 0);
	err = get_dnode_of_data(&dn, 0, LOOKUP_NODE);
	if (err)
		return err;
//.........这里部分代码省略.........

static int recover_dentry(struct inode *inode, struct page *ipage)
{
	struct f2fs_inode *raw_inode = F2FS_INODE(ipage);
	nid_t pino = le32_to_cpu(raw_inode->i_pino);
	struct f2fs_dir_entry *de;
	struct qstr name;
	struct page *page;
	struct inode *dir, *einode;
	int err = 0;

	dir = f2fs_iget(inode->i_sb, pino);
	if (IS_ERR(dir)) {
		err = PTR_ERR(dir);
		goto out;
	}

	if (file_enc_name(inode)) {
		iput(dir);
		return 0;
	}

	name.len = le32_to_cpu(raw_inode->i_namelen);
	name.name = raw_inode->i_name;

	if (unlikely(name.len > F2FS_NAME_LEN)) {
		WARN_ON(1);
		err = -ENAMETOOLONG;
		goto out_err;
	}
retry:
	de = f2fs_find_entry(dir, &name, &page);
	if (de && inode->i_ino == le32_to_cpu(de->ino))
		goto out_unmap_put;

	if (de) {
		einode = f2fs_iget(inode->i_sb, le32_to_cpu(de->ino));
		if (IS_ERR(einode)) {
			WARN_ON(1);
			err = PTR_ERR(einode);
			if (err == -ENOENT)
				err = -EEXIST;
			goto out_unmap_put;
		}
		err = acquire_orphan_inode(F2FS_I_SB(inode));
		if (err) {
			iput(einode);
			goto out_unmap_put;
		}
		f2fs_delete_entry(de, page, dir, einode);
		iput(einode);
		goto retry;
	}
	err = __f2fs_add_link(dir, &name, inode, inode->i_ino, inode->i_mode);
	if (err)
		goto out_err;

	if (is_inode_flag_set(F2FS_I(dir), FI_DELAY_IPUT)) {
		iput(dir);
	} else {
		add_dirty_dir_inode(dir);
		set_inode_flag(F2FS_I(dir), FI_DELAY_IPUT);
	}

	goto out;

out_unmap_put:
	f2fs_dentry_kunmap(dir, page);
	f2fs_put_page(page, 0);
out_err:
	iput(dir);
out:
	f2fs_msg(inode->i_sb, KERN_NOTICE,
			"%s: ino = %x, name = %s, dir = %lx, err = %d",
			__func__, ino_of_node(ipage), raw_inode->i_name,
			IS_ERR(dir) ? 0 : dir->i_ino, err);
	return err;
}

static int __f2fs_setxattr(struct inode *inode, int index,
			const char *name, const void *value, size_t size,
			struct page *ipage, int flags)
{
	struct f2fs_inode_info *fi = F2FS_I(inode);
	struct f2fs_xattr_entry *here, *last;
	void *base_addr;
	int found, newsize;
	size_t len;
	__u32 new_hsize;
	int error = -ENOMEM;

	if (name == NULL)
		return -EINVAL;

	if (value == NULL)
		size = 0;

	len = strlen(name);

	if (len > F2FS_NAME_LEN)
		return -ERANGE;

	if (size > MAX_VALUE_LEN(inode))
		return -E2BIG;

	base_addr = read_all_xattrs(inode, ipage);
	if (!base_addr)
		goto exit;

	/* find entry with wanted name. */
	here = __find_xattr(base_addr, index, len, name);

	found = IS_XATTR_LAST_ENTRY(here) ? 0 : 1;

	if ((flags & XATTR_REPLACE) && !found) {
		error = -ENODATA;
		goto exit;
	} else if ((flags & XATTR_CREATE) && found) {
		error = -EEXIST;
		goto exit;
	}

	last = here;
	while (!IS_XATTR_LAST_ENTRY(last))
		last = XATTR_NEXT_ENTRY(last);

	newsize = XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) + len + size);

	/* 1. Check space */
	if (value) {
		int free;
		/*
		 * If value is NULL, it is remove operation.
		 * In case of update operation, we calculate free.
		 */
		free = MIN_OFFSET(inode) - ((char *)last - (char *)base_addr);
		if (found)
			free = free + ENTRY_SIZE(here);

		if (unlikely(free < newsize)) {
			error = -ENOSPC;
			goto exit;
		}
	}

	/* 2. Remove old entry */
	if (found) {
		/*
		 * If entry is found, remove old entry.
		 * If not found, remove operation is not needed.
		 */
		struct f2fs_xattr_entry *next = XATTR_NEXT_ENTRY(here);
		int oldsize = ENTRY_SIZE(here);

		memmove(here, next, (char *)last - (char *)next);
		last = (struct f2fs_xattr_entry *)((char *)last - oldsize);
		memset(last, 0, oldsize);
	}

	new_hsize = (char *)last - (char *)base_addr;

	/* 3. Write new entry */
	if (value) {
		char *pval;
		/*
		 * Before we come here, old entry is removed.
		 * We just write new entry.
		 */
		memset(last, 0, newsize);
		last->e_name_index = index;
		last->e_name_len = len;
		memcpy(last->e_name, name, len);
		pval = last->e_name + len;
		memcpy(pval, value, size);
		last->e_value_size = cpu_to_le16(size);
		new_hsize += newsize;
	}

	error = write_all_xattrs(inode, new_hsize, base_addr, ipage);
//.........这里部分代码省略.........

static int find_fsync_dnodes(struct f2fs_sb_info *sbi, struct list_head *head)
{
	unsigned long long cp_ver = cur_cp_version(F2FS_CKPT(sbi));
	struct curseg_info *curseg;
	struct page *page;
	block_t blkaddr;
	int err = 0;

	/* get node pages in the current segment */
	curseg = CURSEG_I(sbi, CURSEG_WARM_NODE);
	blkaddr = NEXT_FREE_BLKADDR(sbi, curseg);

	/* read node page */
	page = alloc_page(GFP_F2FS_ZERO);
	if (!page)
		return -ENOMEM;
	lock_page(page);

	while (1) {
		struct fsync_inode_entry *entry;

		err = f2fs_submit_page_bio(sbi, page, blkaddr, READ_SYNC);
		if (err)
			return err;

		lock_page(page);

		if (cp_ver != cpver_of_node(page))
			break;

		if (!is_fsync_dnode(page))
			goto next;

		entry = get_fsync_inode(head, ino_of_node(page));
		if (entry) {
			if (IS_INODE(page) && is_dent_dnode(page))
				set_inode_flag(F2FS_I(entry->inode),
							FI_INC_LINK);
		} else {
			if (IS_INODE(page) && is_dent_dnode(page)) {
				err = recover_inode_page(sbi, page);
				if (err) {
					f2fs_msg(sbi->sb, KERN_INFO,
					 "%s: recover_inode_page failed: %d",
								__func__, err);
					break;
				}
			}

			/* add this fsync inode to the list */
			entry = kmem_cache_alloc(fsync_entry_slab, GFP_NOFS);
			if (!entry) {
				err = -ENOMEM;
				break;
			}

			entry->inode = f2fs_iget(sbi->sb, ino_of_node(page));
			if (IS_ERR(entry->inode)) {
				err = PTR_ERR(entry->inode);
				f2fs_msg(sbi->sb, KERN_INFO,
					"%s: f2fs_iget failed: %d",
					__func__, err);
				kmem_cache_free(fsync_entry_slab, entry);
				break;
			}
			list_add_tail(&entry->list, head);
		}
		entry->blkaddr = blkaddr;

		err = recover_inode(entry->inode, page);
		if (err && err != -ENOENT) {
			f2fs_msg(sbi->sb, KERN_INFO,
				"%s: recover_inode failed: %d",
				__func__, err);
			break;
		}
next:
		/* check next segment */
		blkaddr = next_blkaddr_of_node(page);
	}

	unlock_page(page);
	__free_pages(page, 0);

	return err;
}

int _f2fs_get_encryption_info(struct inode *inode)
{
	struct f2fs_inode_info *fi = F2FS_I(inode);
	struct f2fs_crypt_info *crypt_info;
	char full_key_descriptor[F2FS_KEY_DESC_PREFIX_SIZE +
				(F2FS_KEY_DESCRIPTOR_SIZE * 2) + 1];
	struct key *keyring_key = NULL;
	struct f2fs_encryption_key *master_key;
	struct f2fs_encryption_context ctx;
	const struct user_key_payload *ukp;
	struct crypto_skcipher *ctfm;
	const char *cipher_str;
	char raw_key[F2FS_MAX_KEY_SIZE];
	char mode;
	int res;

	res = f2fs_crypto_initialize();
	if (res)
		return res;
retry:
	crypt_info = ACCESS_ONCE(fi->i_crypt_info);
	if (crypt_info) {
		if (!crypt_info->ci_keyring_key ||
				key_validate(crypt_info->ci_keyring_key) == 0)
			return 0;
		f2fs_free_encryption_info(inode, crypt_info);
		goto retry;
	}

	res = f2fs_getxattr(inode, F2FS_XATTR_INDEX_ENCRYPTION,
				F2FS_XATTR_NAME_ENCRYPTION_CONTEXT,
				&ctx, sizeof(ctx), NULL);
	if (res < 0)
		return res;
	else if (res != sizeof(ctx))
		return -EINVAL;
	res = 0;

	crypt_info = kmem_cache_alloc(f2fs_crypt_info_cachep, GFP_NOFS);
	if (!crypt_info)
		return -ENOMEM;

	crypt_info->ci_flags = ctx.flags;
	crypt_info->ci_data_mode = ctx.contents_encryption_mode;
	crypt_info->ci_filename_mode = ctx.filenames_encryption_mode;
	crypt_info->ci_ctfm = NULL;
	crypt_info->ci_keyring_key = NULL;
	memcpy(crypt_info->ci_master_key, ctx.master_key_descriptor,
				sizeof(crypt_info->ci_master_key));
	if (S_ISREG(inode->i_mode))
		mode = crypt_info->ci_data_mode;
	else if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
		mode = crypt_info->ci_filename_mode;
	else
		BUG();

	switch (mode) {
	case F2FS_ENCRYPTION_MODE_AES_256_XTS:
		cipher_str = "xts(aes)";
		break;
	case F2FS_ENCRYPTION_MODE_AES_256_CTS:
		cipher_str = "cts(cbc(aes))";
		break;
	default:
		printk_once(KERN_WARNING
			    "f2fs: unsupported key mode %d (ino %u)\n",
			    mode, (unsigned) inode->i_ino);
		res = -ENOKEY;
		goto out;
	}

	memcpy(full_key_descriptor, F2FS_KEY_DESC_PREFIX,
					F2FS_KEY_DESC_PREFIX_SIZE);
	sprintf(full_key_descriptor + F2FS_KEY_DESC_PREFIX_SIZE,
					"%*phN", F2FS_KEY_DESCRIPTOR_SIZE,
					ctx.master_key_descriptor);
	full_key_descriptor[F2FS_KEY_DESC_PREFIX_SIZE +
					(2 * F2FS_KEY_DESCRIPTOR_SIZE)] = '\0';
	keyring_key = request_key(&key_type_logon, full_key_descriptor, NULL);
	if (IS_ERR(keyring_key)) {
		res = PTR_ERR(keyring_key);
		keyring_key = NULL;
		goto out;
	}
	crypt_info->ci_keyring_key = keyring_key;
	BUG_ON(keyring_key->type != &key_type_logon);
	ukp = user_key_payload(keyring_key);
	if (ukp->datalen != sizeof(struct f2fs_encryption_key)) {
		res = -EINVAL;
		goto out;
	}
	master_key = (struct f2fs_encryption_key *)ukp->data;
	BUILD_BUG_ON(F2FS_AES_128_ECB_KEY_SIZE !=
				F2FS_KEY_DERIVATION_NONCE_SIZE);
	BUG_ON(master_key->size != F2FS_AES_256_XTS_KEY_SIZE);
	res = f2fs_derive_key_aes(ctx.nonce, master_key->raw,
				  raw_key);
	if (res)
		goto out;

//.........这里部分代码省略.........

int f2fs_has_encryption_key(struct inode *inode)
{
	struct f2fs_inode_info *fi = F2FS_I(inode);

	return (fi->i_crypt_info != NULL);
}

static int f2fs_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
			     struct inode *new_dir, struct dentry *new_dentry)
{
	struct f2fs_sb_info *sbi = F2FS_I_SB(old_dir);
	struct inode *old_inode = old_dentry->d_inode;
	struct inode *new_inode = new_dentry->d_inode;
	struct page *old_dir_page, *new_dir_page;
	struct page *old_page, *new_page;
	struct f2fs_dir_entry *old_dir_entry = NULL, *new_dir_entry = NULL;
	struct f2fs_dir_entry *old_entry, *new_entry;
	int old_nlink = 0, new_nlink = 0;
	int err = -ENOENT;

	f2fs_balance_fs(sbi);

	old_entry = f2fs_find_entry(old_dir, &old_dentry->d_name, &old_page);
	if (!old_entry)
		goto out;

	new_entry = f2fs_find_entry(new_dir, &new_dentry->d_name, &new_page);
	if (!new_entry)
		goto out_old;

	/* prepare for updating ".." directory entry info later */
	if (old_dir != new_dir) {
		if (S_ISDIR(old_inode->i_mode)) {
			err = -EIO;
			old_dir_entry = f2fs_parent_dir(old_inode,
							&old_dir_page);
			if (!old_dir_entry)
				goto out_new;
		}

		if (S_ISDIR(new_inode->i_mode)) {
			err = -EIO;
			new_dir_entry = f2fs_parent_dir(new_inode,
							&new_dir_page);
			if (!new_dir_entry)
				goto out_old_dir;
		}
	}

	/*
	 * If cross rename between file and directory those are not
	 * in the same directory, we will inc nlink of file's parent
	 * later, so we should check upper boundary of its nlink.
	 */
	if ((!old_dir_entry || !new_dir_entry) &&
				old_dir_entry != new_dir_entry) {
		old_nlink = old_dir_entry ? -1 : 1;
		new_nlink = -old_nlink;
		err = -EMLINK;
		if ((old_nlink > 0 && old_inode->i_nlink >= F2FS_LINK_MAX) ||
			(new_nlink > 0 && new_inode->i_nlink >= F2FS_LINK_MAX))
			goto out_new_dir;
	}

	f2fs_lock_op(sbi);

	err = update_dent_inode(old_inode, &new_dentry->d_name);
	if (err)
		goto out_unlock;

	err = update_dent_inode(new_inode, &old_dentry->d_name);
	if (err)
		goto out_undo;

	/* update ".." directory entry info of old dentry */
	if (old_dir_entry)
		f2fs_set_link(old_inode, old_dir_entry, old_dir_page, new_dir);

	/* update ".." directory entry info of new dentry */
	if (new_dir_entry)
		f2fs_set_link(new_inode, new_dir_entry, new_dir_page, old_dir);

	/* update directory entry info of old dir inode */
	f2fs_set_link(old_dir, old_entry, old_page, new_inode);

	down_write(&F2FS_I(old_inode)->i_sem);
	file_lost_pino(old_inode);
	up_write(&F2FS_I(old_inode)->i_sem);

	update_inode_page(old_inode);

	old_dir->i_ctime = CURRENT_TIME;
	if (old_nlink) {
		down_write(&F2FS_I(old_dir)->i_sem);
		if (old_nlink < 0)
			drop_nlink(old_dir);
		else
			inc_nlink(old_dir);
		up_write(&F2FS_I(old_dir)->i_sem);
	}
	mark_inode_dirty(old_dir);
	update_inode_page(old_dir);

	/* update directory entry info of new dir inode */
	f2fs_set_link(new_dir, new_entry, new_page, old_inode);

	down_write(&F2FS_I(new_inode)->i_sem);
//.........这里部分代码省略.........

int f2fs_setxattr(struct inode *inode, int name_index, const char *name,
			const void *value, size_t value_len, struct page *ipage)
{
	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
	struct f2fs_inode_info *fi = F2FS_I(inode);
	struct f2fs_xattr_header *header = NULL;
	struct f2fs_xattr_entry *here, *last;
	struct page *page;
	void *base_addr;
	int error, found, free, newsize;
	size_t name_len;
	char *pval;
	int ilock;

	if (name == NULL)
		return -EINVAL;

	if (value == NULL)
		value_len = 0;

	name_len = strlen(name);

	if (name_len > F2FS_NAME_LEN || value_len > MAX_VALUE_LEN)
		return -ERANGE;

	f2fs_balance_fs(sbi);

	ilock = mutex_lock_op(sbi);

	if (!fi->i_xattr_nid) {
		/* Allocate new attribute block */
		struct dnode_of_data dn;

		if (!alloc_nid(sbi, &fi->i_xattr_nid)) {
			error = -ENOSPC;
			goto exit;
		}
		set_new_dnode(&dn, inode, NULL, NULL, fi->i_xattr_nid);
		mark_inode_dirty(inode);

		page = new_node_page(&dn, XATTR_NODE_OFFSET, ipage);
		if (IS_ERR(page)) {
			alloc_nid_failed(sbi, fi->i_xattr_nid);
			fi->i_xattr_nid = 0;
			error = PTR_ERR(page);
			goto exit;
		}

		alloc_nid_done(sbi, fi->i_xattr_nid);
		base_addr = page_address(page);
		header = XATTR_HDR(base_addr);
		header->h_magic = cpu_to_le32(F2FS_XATTR_MAGIC);
		header->h_refcount = cpu_to_le32(1);
	} else {
		/* The inode already has an extended attribute block. */
		page = get_node_page(sbi, fi->i_xattr_nid);
		if (IS_ERR(page)) {
			error = PTR_ERR(page);
			goto exit;
		}

		base_addr = page_address(page);
		header = XATTR_HDR(base_addr);
	}

	if (le32_to_cpu(header->h_magic) != F2FS_XATTR_MAGIC) {
		error = -EIO;
		goto cleanup;
	}

	/* find entry with wanted name. */
	found = 0;
	list_for_each_xattr(here, base_addr) {
		if (here->e_name_index != name_index)
			continue;
		if (here->e_name_len != name_len)
			continue;
		if (!memcmp(here->e_name, name, name_len)) {
			found = 1;
			break;
		}
	}

	last = here;

	while (!IS_XATTR_LAST_ENTRY(last))
		last = XATTR_NEXT_ENTRY(last);

	newsize = XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) +
			name_len + value_len);

	/* 1. Check space */
	if (value) {
		/* If value is NULL, it is remove operation.
		 * In case of update operation, we caculate free.
		 */
		free = MIN_OFFSET - ((char *)last - (char *)header);
		if (found)
			free = free - ENTRY_SIZE(here);

//.........这里部分代码省略.........

//.........这里部分代码省略.........
	unlock_new_inode(inode);
	return err;
out:
	clear_nlink(inode);
	unlock_new_inode(inode);
	make_bad_inode(inode);
	iput(inode);
	alloc_nid_failed(sbi, inode->i_ino);
	return err;
}

static int f2fs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
	struct f2fs_sb_info *sbi;
	struct inode *inode;
	int err;

	if (dir->i_nlink >= F2FS_LINK_MAX)
		return -EMLINK;

	sbi = F2FS_SB(dir->i_sb);

	f2fs_balance_fs(sbi);

	inode = f2fs_new_inode(dir, S_IFDIR | mode);
	if (IS_ERR(inode))
		return PTR_ERR(inode);

	inode->i_op = &f2fs_dir_inode_operations;
	inode->i_fop = &f2fs_dir_operations;
	inode->i_mapping->a_ops = &f2fs_dblock_aops;
	mapping_set_gfp_mask(inode->i_mapping, GFP_F2FS_ZERO);

	set_inode_flag(F2FS_I(inode), FI_INC_LINK);
	f2fs_lock_op(sbi);
	err = f2fs_add_link(dentry, inode);
	f2fs_unlock_op(sbi);
	if (err)
		goto out_fail;

	alloc_nid_done(sbi, inode->i_ino);

	d_instantiate(dentry, inode);
	unlock_new_inode(inode);

	return 0;

out_fail:
	clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
	clear_nlink(inode);
	unlock_new_inode(inode);
	make_bad_inode(inode);
	iput(inode);
	alloc_nid_failed(sbi, inode->i_ino);
	return err;
}

static int f2fs_rmdir(struct inode *dir, struct dentry *dentry)
{
	struct inode *inode = dentry->d_inode;
	if (f2fs_empty_dir(inode))
		return f2fs_unlink(dir, dentry);
	return -ENOTEMPTY;
}

static int f2fs_mknod(struct inode *dir, struct dentry *dentry,

static int find_fsync_dnodes(struct f2fs_sb_info *sbi, struct list_head *head)
{
	unsigned long long cp_ver = cur_cp_version(F2FS_CKPT(sbi));
	struct curseg_info *curseg;
	struct page *page = NULL;
	block_t blkaddr;
	int err = 0;

	/* get node pages in the current segment */
	curseg = CURSEG_I(sbi, CURSEG_WARM_NODE);
	blkaddr = NEXT_FREE_BLKADDR(sbi, curseg);

	ra_meta_pages(sbi, blkaddr, 1, META_POR);

	while (1) {
		struct fsync_inode_entry *entry;

		if (blkaddr < MAIN_BLKADDR(sbi) || blkaddr >= MAX_BLKADDR(sbi))
			return 0;

		page = get_meta_page(sbi, blkaddr);

		if (cp_ver != cpver_of_node(page))
			break;

		if (!is_fsync_dnode(page))
			goto next;

		entry = get_fsync_inode(head, ino_of_node(page));
		if (entry) {
			if (IS_INODE(page) && is_dent_dnode(page))
				set_inode_flag(F2FS_I(entry->inode),
							FI_INC_LINK);
		} else {
			if (IS_INODE(page) && is_dent_dnode(page)) {
				err = recover_inode_page(sbi, page);
				if (err)
					break;
			}

			/* add this fsync inode to the list */
			entry = kmem_cache_alloc(fsync_entry_slab, GFP_F2FS_ZERO);
			if (!entry) {
				err = -ENOMEM;
				break;
			}
			/*
			 * CP | dnode(F) | inode(DF)
			 * For this case, we should not give up now.
			 */
			entry->inode = f2fs_iget(sbi->sb, ino_of_node(page));
			if (IS_ERR(entry->inode)) {
				err = PTR_ERR(entry->inode);
				kmem_cache_free(fsync_entry_slab, entry);
				if (err == -ENOENT)
					goto next;
				break;
			}
			list_add_tail(&entry->list, head);
		}
		entry->blkaddr = blkaddr;

		if (IS_INODE(page)) {
			entry->last_inode = blkaddr;
			if (is_dent_dnode(page))
				entry->last_dentry = blkaddr;
		}
next:
		/* check next segment */
		blkaddr = next_blkaddr_of_node(page);
		f2fs_put_page(page, 1);

		ra_meta_pages_cond(sbi, blkaddr);
	}
	f2fs_put_page(page, 1);
	return err;
}

/*
 * Called at the last iput() if i_nlink is zero
 */
void f2fs_evict_inode(struct inode *inode)
{
	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
	nid_t xnid = F2FS_I(inode)->i_xattr_nid;
	int err = 0;

	/* some remained atomic pages should discarded */
	if (f2fs_is_atomic_file(inode))
		drop_inmem_pages(inode);

	trace_f2fs_evict_inode(inode);
	truncate_inode_pages_final(&inode->i_data);

	if (inode->i_ino == F2FS_NODE_INO(sbi) ||
			inode->i_ino == F2FS_META_INO(sbi))
		goto out_clear;

	f2fs_bug_on(sbi, get_dirty_pages(inode));
	remove_dirty_inode(inode);

	f2fs_destroy_extent_tree(inode);

	if (inode->i_nlink || is_bad_inode(inode))
		goto no_delete;

	remove_ino_entry(sbi, inode->i_ino, APPEND_INO);
	remove_ino_entry(sbi, inode->i_ino, UPDATE_INO);

	sb_start_intwrite(inode->i_sb);
	set_inode_flag(inode, FI_NO_ALLOC);
	i_size_write(inode, 0);
retry:
	if (F2FS_HAS_BLOCKS(inode))
		err = f2fs_truncate(inode);

#ifdef CONFIG_F2FS_FAULT_INJECTION
	if (time_to_inject(sbi, FAULT_EVICT_INODE)) {
		f2fs_show_injection_info(FAULT_EVICT_INODE);
		err = -EIO;
	}
#endif
	if (!err) {
		f2fs_lock_op(sbi);
		err = remove_inode_page(inode);
		f2fs_unlock_op(sbi);
		if (err == -ENOENT)
			err = 0;
	}

	/* give more chances, if ENOMEM case */
	if (err == -ENOMEM) {
		err = 0;
		goto retry;
	}

	if (err)
		update_inode_page(inode);
	sb_end_intwrite(inode->i_sb);
no_delete:
	stat_dec_inline_xattr(inode);
	stat_dec_inline_dir(inode);
	stat_dec_inline_inode(inode);

	/* ino == 0, if f2fs_new_inode() was failed t*/
	if (inode->i_ino)
		invalidate_mapping_pages(NODE_MAPPING(sbi), inode->i_ino,
							inode->i_ino);
	if (xnid)
		invalidate_mapping_pages(NODE_MAPPING(sbi), xnid, xnid);
	if (inode->i_nlink) {
		if (is_inode_flag_set(inode, FI_APPEND_WRITE))
			add_ino_entry(sbi, inode->i_ino, APPEND_INO);
		if (is_inode_flag_set(inode, FI_UPDATE_WRITE))
			add_ino_entry(sbi, inode->i_ino, UPDATE_INO);
	}
	if (is_inode_flag_set(inode, FI_FREE_NID)) {
		alloc_nid_failed(sbi, inode->i_ino);
		clear_inode_flag(inode, FI_FREE_NID);
	}
	f2fs_bug_on(sbi, err &&
		!exist_written_data(sbi, inode->i_ino, ORPHAN_INO));
out_clear:
	fscrypt_put_encryption_info(inode, NULL);
	clear_inode(inode);
}

/*
 * Caller should grab and release a rwsem by calling f2fs_lock_op() and
 * f2fs_unlock_op().
 */
int __f2fs_add_link(struct inode *dir, const struct qstr *name,
						struct inode *inode)
{
	unsigned int bit_pos;
	unsigned int level;
	unsigned int current_depth;
	unsigned long bidx, block;
	f2fs_hash_t dentry_hash;
	struct f2fs_dir_entry *de;
	unsigned int nbucket, nblock;
	size_t namelen = name->len;
	struct page *dentry_page = NULL;
	struct f2fs_dentry_block *dentry_blk = NULL;
	int slots = GET_DENTRY_SLOTS(namelen);
	struct page *page;
	int err = 0;
	int i;

	dentry_hash = f2fs_dentry_hash(name->name, name->len);
	level = 0;
	current_depth = F2FS_I(dir)->i_current_depth;
	if (F2FS_I(dir)->chash == dentry_hash) {
		level = F2FS_I(dir)->clevel;
		F2FS_I(dir)->chash = 0;
	}

start:
	if (unlikely(current_depth == MAX_DIR_HASH_DEPTH))
		return -ENOSPC;

	/* Increase the depth, if required */
	if (level == current_depth)
		++current_depth;

	nbucket = dir_buckets(level);
	nblock = bucket_blocks(level);

	bidx = dir_block_index(level, (le32_to_cpu(dentry_hash) % nbucket));

	for (block = bidx; block <= (bidx + nblock - 1); block++) {
		dentry_page = get_new_data_page(dir, NULL, block, true);
		if (IS_ERR(dentry_page))
			return PTR_ERR(dentry_page);

		dentry_blk = kmap(dentry_page);
		bit_pos = room_for_filename(dentry_blk, slots);
		if (bit_pos < NR_DENTRY_IN_BLOCK)
			goto add_dentry;

		kunmap(dentry_page);
		f2fs_put_page(dentry_page, 1);
	}

	/* Move to next level to find the empty slot for new dentry */
	++level;
	goto start;
add_dentry:
	wait_on_page_writeback(dentry_page);

	page = init_inode_metadata(inode, dir, name);
	if (IS_ERR(page)) {
		err = PTR_ERR(page);
		goto fail;
	}
	de = &dentry_blk->dentry[bit_pos];
	de->hash_code = dentry_hash;
	de->name_len = cpu_to_le16(namelen);
	memcpy(dentry_blk->filename[bit_pos], name->name, name->len);
	de->ino = cpu_to_le32(inode->i_ino);
	set_de_type(de, inode);
	for (i = 0; i < slots; i++)
		test_and_set_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
	set_page_dirty(dentry_page);

	/* we don't need to mark_inode_dirty now */
	F2FS_I(inode)->i_pino = dir->i_ino;
	update_inode(inode, page);
	f2fs_put_page(page, 1);

	update_parent_metadata(dir, inode, current_depth);
fail:
	clear_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
	kunmap(dentry_page);
	f2fs_put_page(dentry_page, 1);
	return err;
}

int f2fs_add_inline_entry(struct inode *dir, const struct qstr *new_name,
				const struct qstr *orig_name,
				struct inode *inode, nid_t ino, umode_t mode)
{
	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
	struct page *ipage;
	unsigned int bit_pos;
	f2fs_hash_t name_hash;
	struct f2fs_inline_dentry *inline_dentry = NULL;
	struct f2fs_dentry_ptr d;
	int slots = GET_DENTRY_SLOTS(new_name->len);
	struct page *page = NULL;
	int err = 0;

	ipage = get_node_page(sbi, dir->i_ino);
	if (IS_ERR(ipage))
		return PTR_ERR(ipage);

	inline_dentry = inline_data_addr(ipage);
	bit_pos = room_for_filename(&inline_dentry->dentry_bitmap,
						slots, NR_INLINE_DENTRY);
	if (bit_pos >= NR_INLINE_DENTRY) {
		err = f2fs_convert_inline_dir(dir, ipage, inline_dentry);
		if (err)
			return err;
		err = -EAGAIN;
		goto out;
	}

	if (inode) {
		down_write(&F2FS_I(inode)->i_sem);
		page = init_inode_metadata(inode, dir, new_name,
						orig_name, ipage);
		if (IS_ERR(page)) {
			err = PTR_ERR(page);
			goto fail;
		}
	}

	f2fs_wait_on_page_writeback(ipage, NODE, true);

	name_hash = f2fs_dentry_hash(new_name, NULL);
	make_dentry_ptr_inline(NULL, &d, inline_dentry);
	f2fs_update_dentry(ino, mode, &d, new_name, name_hash, bit_pos);

	set_page_dirty(ipage);

	/* we don't need to mark_inode_dirty now */
	if (inode) {
		f2fs_i_pino_write(inode, dir->i_ino);
		f2fs_put_page(page, 1);
	}

	update_parent_metadata(dir, inode, 0);
fail:
	if (inode)
		up_write(&F2FS_I(inode)->i_sem);
out:
	f2fs_put_page(ipage, 1);
	return err;
}

static inline int write_all_xattrs(struct inode *inode, __u32 hsize,
				void *txattr_addr, struct page *ipage)
{
	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
	size_t inline_size = 0;
	void *xattr_addr;
	struct page *xpage;
	nid_t new_nid = 0;
	int err;

	inline_size = inline_xattr_size(inode);

	if (hsize > inline_size && !F2FS_I(inode)->i_xattr_nid)
		if (!alloc_nid(sbi, &new_nid))
			return -ENOSPC;

	/* write to inline xattr */
	if (inline_size) {
		struct page *page = NULL;
		void *inline_addr;

		if (ipage) {
			inline_addr = inline_xattr_addr(ipage);
			f2fs_wait_on_page_writeback(ipage, NODE);
		} else {
			page = get_node_page(sbi, inode->i_ino);
			if (IS_ERR(page)) {
				alloc_nid_failed(sbi, new_nid);
				return PTR_ERR(page);
			}
			inline_addr = inline_xattr_addr(page);
			f2fs_wait_on_page_writeback(page, NODE);
		}
		memcpy(inline_addr, txattr_addr, inline_size);
		f2fs_put_page(page, 1);

		/* no need to use xattr node block */
		if (hsize <= inline_size) {
			err = truncate_xattr_node(inode, ipage);
			alloc_nid_failed(sbi, new_nid);
			return err;
		}
	}

	/* write to xattr node block */
	if (F2FS_I(inode)->i_xattr_nid) {
		xpage = get_node_page(sbi, F2FS_I(inode)->i_xattr_nid);
		if (IS_ERR(xpage)) {
			alloc_nid_failed(sbi, new_nid);
			return PTR_ERR(xpage);
		}
		f2fs_bug_on(sbi, new_nid);
		f2fs_wait_on_page_writeback(xpage, NODE);
	} else {
		struct dnode_of_data dn;
		set_new_dnode(&dn, inode, NULL, NULL, new_nid);
		xpage = new_node_page(&dn, XATTR_NODE_OFFSET, ipage);
		if (IS_ERR(xpage)) {
			alloc_nid_failed(sbi, new_nid);
			return PTR_ERR(xpage);
		}
		alloc_nid_done(sbi, new_nid);
	}

	xattr_addr = page_address(xpage);
	memcpy(xattr_addr, txattr_addr + inline_size, PAGE_SIZE -
						sizeof(struct node_footer));
	set_page_dirty(xpage);
	f2fs_put_page(xpage, 1);

	/* need to checkpoint during fsync */
	F2FS_I(inode)->xattr_ver = cur_cp_version(F2FS_CKPT(sbi));
	return 0;
}

static inline int write_all_xattrs(struct inode *inode, __u32 hsize,
				void *txattr_addr, struct page *ipage)
{
	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
	size_t inline_size = inline_xattr_size(inode);
	struct page *in_page = NULL;
	void *xattr_addr;
	void *inline_addr = NULL;
	struct page *xpage;
	nid_t new_nid = 0;
	int err = 0;

	if (hsize > inline_size && !F2FS_I(inode)->i_xattr_nid)
		if (!alloc_nid(sbi, &new_nid))
			return -ENOSPC;

	/* write to inline xattr */
	if (inline_size) {
		if (ipage) {
			inline_addr = inline_xattr_addr(inode, ipage);
		} else {
			in_page = get_node_page(sbi, inode->i_ino);
			if (IS_ERR(in_page)) {
				alloc_nid_failed(sbi, new_nid);
				return PTR_ERR(in_page);
			}
			inline_addr = inline_xattr_addr(inode, in_page);
		}

		f2fs_wait_on_page_writeback(ipage ? ipage : in_page,
							NODE, true);
		/* no need to use xattr node block */
		if (hsize <= inline_size) {
			err = truncate_xattr_node(inode);
			alloc_nid_failed(sbi, new_nid);
			if (err) {
				f2fs_put_page(in_page, 1);
				return err;
			}
			memcpy(inline_addr, txattr_addr, inline_size);
			set_page_dirty(ipage ? ipage : in_page);
			goto in_page_out;
		}
	}

	/* write to xattr node block */
	if (F2FS_I(inode)->i_xattr_nid) {
		xpage = get_node_page(sbi, F2FS_I(inode)->i_xattr_nid);
		if (IS_ERR(xpage)) {
			alloc_nid_failed(sbi, new_nid);
			goto in_page_out;
		}
		f2fs_bug_on(sbi, new_nid);
		f2fs_wait_on_page_writeback(xpage, NODE, true);
	} else {
		struct dnode_of_data dn;
		set_new_dnode(&dn, inode, NULL, NULL, new_nid);
		xpage = new_node_page(&dn, XATTR_NODE_OFFSET);
		if (IS_ERR(xpage)) {
			alloc_nid_failed(sbi, new_nid);
			goto in_page_out;
		}
		alloc_nid_done(sbi, new_nid);
	}
	xattr_addr = page_address(xpage);

	if (inline_size)
		memcpy(inline_addr, txattr_addr, inline_size);
	memcpy(xattr_addr, txattr_addr + inline_size, VALID_XATTR_BLOCK_SIZE);

	if (inline_size)
		set_page_dirty(ipage ? ipage : in_page);
	set_page_dirty(xpage);

	f2fs_put_page(xpage, 1);
in_page_out:
	f2fs_put_page(in_page, 1);
	return err;
}

struct inode *f2fs_iget_nowait(struct super_block *sb, unsigned long ino)
{
	struct f2fs_iget_args args = {
		.ino = ino,
		.on_free = 0
	};
	struct inode *inode = ilookup5(sb, ino, f2fs_iget_test, &args);

	if (inode)
		return inode;
	if (!args.on_free)
		return f2fs_iget(sb, ino);
	return ERR_PTR(-ENOENT);
}

static int do_read_inode(struct inode *inode)
{
	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
	struct f2fs_inode_info *fi = F2FS_I(inode);
	struct page *node_page;
	struct f2fs_node *rn;
	struct f2fs_inode *ri;

	/* Check if ino is within scope */
	check_nid_range(sbi, inode->i_ino);

	node_page = get_node_page(sbi, inode->i_ino);
	if (IS_ERR(node_page))
		return PTR_ERR(node_page);

	rn = page_address(node_page);
	ri = &(rn->i);

	inode->i_mode = le16_to_cpu(ri->i_mode);
	i_uid_write(inode, le32_to_cpu(ri->i_uid));
	i_gid_write(inode, le32_to_cpu(ri->i_gid));
	set_nlink(inode, le32_to_cpu(ri->i_links));
	inode->i_size = le64_to_cpu(ri->i_size);
	inode->i_blocks = le64_to_cpu(ri->i_blocks);

	inode->i_atime.tv_sec = le64_to_cpu(ri->i_atime);
	inode->i_ctime.tv_sec = le64_to_cpu(ri->i_ctime);
	inode->i_mtime.tv_sec = le64_to_cpu(ri->i_mtime);
	inode->i_atime.tv_nsec = le32_to_cpu(ri->i_atime_nsec);
	inode->i_ctime.tv_nsec = le32_to_cpu(ri->i_ctime_nsec);
	inode->i_mtime.tv_nsec = le32_to_cpu(ri->i_mtime_nsec);
	inode->i_generation = le32_to_cpu(ri->i_generation);

	fi->i_current_depth = le32_to_cpu(ri->i_current_depth);
	fi->i_xattr_nid = le32_to_cpu(ri->i_xattr_nid);
	fi->i_flags = le32_to_cpu(ri->i_flags);
	fi->flags = 0;
	fi->data_version = le64_to_cpu(F2FS_CKPT(sbi)->checkpoint_ver) - 1;
	fi->i_advise = ri->i_advise;
	fi->i_pino = le32_to_cpu(ri->i_pino);
	get_extent_info(&fi->ext, ri->i_ext);
	f2fs_put_page(node_page, 1);
	return 0;
}

struct inode *f2fs_iget(struct super_block *sb, unsigned long ino)
{
	struct f2fs_sb_info *sbi = F2FS_SB(sb);
	struct inode *inode;
	int ret;

	inode = iget_locked(sb, ino);
	if (!inode)
		return ERR_PTR(-ENOMEM);
	if (!(inode->i_state & I_NEW))
		return inode;
	if (ino == F2FS_NODE_INO(sbi) || ino == F2FS_META_INO(sbi))
		goto make_now;

	ret = do_read_inode(inode);
	if (ret)
		goto bad_inode;

	if (!sbi->por_doing && inode->i_nlink == 0) {
		ret = -ENOENT;
		goto bad_inode;
	}

make_now:
	if (ino == F2FS_NODE_INO(sbi)) {
		inode->i_mapping->a_ops = &f2fs_node_aops;
		mapping_set_gfp_mask(inode->i_mapping, GFP_F2FS_ZERO);
	} else if (ino == F2FS_META_INO(sbi)) {
		inode->i_mapping->a_ops = &f2fs_meta_aops;
		mapping_set_gfp_mask(inode->i_mapping, GFP_F2FS_ZERO);
	} else if (S_ISREG(inode->i_mode)) {
		inode->i_op = &f2fs_file_inode_operations;
		inode->i_fop = &f2fs_file_operations;
		inode->i_mapping->a_ops = &f2fs_dblock_aops;
	} else if (S_ISDIR(inode->i_mode)) {
		inode->i_op = &f2fs_dir_inode_operations;
		inode->i_fop = &f2fs_dir_operations;
		inode->i_mapping->a_ops = &f2fs_dblock_aops;
		mapping_set_gfp_mask(inode->i_mapping, GFP_HIGHUSER_MOVABLE |
				__GFP_ZERO);
//.........这里部分代码省略.........

struct dentry *f2fs_get_parent(struct dentry *child)
{
	struct qstr dotdot = {.len = 2, .name = ".."};
	unsigned long ino = f2fs_inode_by_name(child->d_inode, &dotdot);
	if (!ino)
		return ERR_PTR(-ENOENT);
	return d_obtain_alias(f2fs_iget(child->d_inode->i_sb, ino));
}

static int __recover_dot_dentries(struct inode *dir, nid_t pino)
{
	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
	struct qstr dot = {.len = 1, .name = "."};
	struct qstr dotdot = {.len = 2, .name = ".."};
	struct f2fs_dir_entry *de;
	struct page *page;
	int err = 0;

	f2fs_lock_op(sbi);

	de = f2fs_find_entry(dir, &dot, &page);
	if (de) {
		f2fs_dentry_kunmap(dir, page);
		f2fs_put_page(page, 0);
	} else {
		err = __f2fs_add_link(dir, &dot, NULL, dir->i_ino, S_IFDIR);
		if (err)
			goto out;
	}

	de = f2fs_find_entry(dir, &dotdot, &page);
	if (de) {
		f2fs_dentry_kunmap(dir, page);
		f2fs_put_page(page, 0);
	} else {
		err = __f2fs_add_link(dir, &dotdot, NULL, pino, S_IFDIR);
	}
out:
	if (!err) {
		clear_inode_flag(F2FS_I(dir), FI_INLINE_DOTS);
		mark_inode_dirty(dir);
	}

	f2fs_unlock_op(sbi);
	return err;
}

static struct dentry *f2fs_lookup(struct inode *dir, struct dentry *dentry,
					struct nameidata *nd)
{
	struct inode *inode = NULL;
	struct f2fs_dir_entry *de;
	struct page *page;
	nid_t ino;
	int err = 0;

	if (dentry->d_name.len > F2FS_NAME_LEN)
		return ERR_PTR(-ENAMETOOLONG);

	de = f2fs_find_entry(dir, &dentry