fs/f2fs/recovery.c - kernel/msm-4.9 - Gitiles

 /*
  * fs/f2fs/recovery.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/fs.h>
 #include <linux/f2fs_fs.h>
 #include "f2fs.h"
 #include "node.h"
 #include "segment.h"

 static struct kmem_cache *fsync_entry_slab;

 bool space_for_roll_forward(struct f2fs_sb_info *sbi)
 {
 	if (sbi->last_valid_block_count + sbi->alloc_valid_block_count
 			> sbi->user_block_count)
 		return false;
 	return true;
 }

 static struct fsync_inode_entry *get_fsync_inode(struct list_head *head,
 								nid_t ino)
 {
 	struct list_head *this;
 	struct fsync_inode_entry *entry;

 	list_for_each(this, head) {
 		entry = list_entry(this, struct fsync_inode_entry, list);
 		if (entry->inode->i_ino == ino)
 			return entry;
 	}
 	return NULL;
 }

 static int recover_dentry(struct page *ipage, struct inode *inode)
 {
 	void *kaddr = page_address(ipage);
 	struct f2fs_node *raw_node = (struct f2fs_node *)kaddr;
 	struct f2fs_inode *raw_inode = &(raw_node->i);
 	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 = check_dirty_dir_inode(F2FS_SB(inode->i_sb), pino);
 	if (!dir) {
 		dir = f2fs_iget(inode->i_sb, pino);
 		if (IS_ERR(dir)) {
 			err = PTR_ERR(dir);
 			goto out;
 		}
 		set_inode_flag(F2FS_I(dir), FI_DELAY_IPUT);
 		add_dirty_dir_inode(dir);
 	}

 	name.len = le32_to_cpu(raw_inode->i_namelen);
 	name.name = raw_inode->i_name;
 retry:
 	de = f2fs_find_entry(dir, &name, &page);
 	if (de && inode->i_ino == le32_to_cpu(de->ino)) {
 		kunmap(page);
 		f2fs_put_page(page, 0);
 		goto out;
 	}
 	if (de) {
 		einode = f2fs_iget(inode->i_sb, le32_to_cpu(de->ino));
 		if (IS_ERR(einode)) {
 			WARN_ON(1);
 			if (PTR_ERR(einode) == -ENOENT)
 				err = -EEXIST;
 			goto out;
 		}
 		f2fs_delete_entry(de, page, einode);
 		iput(einode);
 		goto retry;
 	}
 	err = __f2fs_add_link(dir, &name, inode);
 out:
 	f2fs_msg(inode->i_sb, KERN_NOTICE, "recover_inode and its dentry: "
 			"ino = %x, name = %s, dir = %lx, err = %d",
 			ino_of_node(ipage), raw_inode->i_name,
 			IS_ERR(dir) ? 0 : dir->i_ino, err);
 	return err;
 }

 static int recover_inode(struct inode *inode, struct page *node_page)
 {
 	void *kaddr = page_address(node_page);
 	struct f2fs_node *raw_node = (struct f2fs_node *)kaddr;
 	struct f2fs_inode *raw_inode = &(raw_node->i);

 	if (!IS_INODE(node_page))
 		return 0;

 	inode->i_mode = le16_to_cpu(raw_inode->i_mode);
 	i_size_write(inode, le64_to_cpu(raw_inode->i_size));
 	inode->i_atime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
 	inode->i_ctime.tv_sec = le64_to_cpu(raw_inode->i_ctime);
 	inode->i_mtime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
 	inode->i_atime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);
 	inode->i_ctime.tv_nsec = le32_to_cpu(raw_inode->i_ctime_nsec);
 	inode->i_mtime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);

 	if (is_dent_dnode(node_page))
 		return recover_dentry(node_page, inode);

 	f2fs_msg(inode->i_sb, KERN_NOTICE, "recover_inode: ino = %x, name = %s",
 			ino_of_node(node_page), raw_inode->i_name);
 	return 0;
 }

 static int find_fsync_dnodes(struct f2fs_sb_info *sbi, struct list_head *head)
 {
 	unsigned long long cp_ver = le64_to_cpu(sbi->ckpt->checkpoint_ver);
 	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 = START_BLOCK(sbi, curseg->segno) + curseg->next_blkoff;

 	/* read node page */
 	page = alloc_page(GFP_F2FS_ZERO);
 	if (IS_ERR(page))
 		return PTR_ERR(page);
 	lock_page(page);

 	while (1) {
 		struct fsync_inode_entry *entry;

 		err = f2fs_readpage(sbi, page, blkaddr, READ_SYNC);
 		if (err)
 			goto out;

 		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)
 					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);
 				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)
 			break;
 next:
 		/* check next segment */
 		blkaddr = next_blkaddr_of_node(page);
 	}
 	unlock_page(page);
 out:
 	__free_pages(page, 0);
 	return err;
 }

 static void destroy_fsync_dnodes(struct list_head *head)
 {
 	struct fsync_inode_entry *entry, *tmp;

 	list_for_each_entry_safe(entry, tmp, head, list) {
 		iput(entry->inode);
 		list_del(&entry->list);
 		kmem_cache_free(fsync_entry_slab, entry);
 	}
 }

 static int check_index_in_prev_nodes(struct f2fs_sb_info *sbi,
 			block_t blkaddr, struct dnode_of_data *dn)
 {
 	struct seg_entry *sentry;
 	unsigned int segno = GET_SEGNO(sbi, blkaddr);
 	unsigned short blkoff = GET_SEGOFF_FROM_SEG0(sbi, blkaddr) &
 					(sbi->blocks_per_seg - 1);
 	struct f2fs_summary sum;
 	nid_t ino, nid;
 	void *kaddr;
 	struct inode *inode;
 	struct page *node_page;
 	block_t bidx;
 	int i;

 	sentry = get_seg_entry(sbi, segno);
 	if (!f2fs_test_bit(blkoff, sentry->cur_valid_map))
 		return 0;

 	/* Get the previous summary */
 	for (i = CURSEG_WARM_DATA; i <= CURSEG_COLD_DATA; i++) {
 		struct curseg_info *curseg = CURSEG_I(sbi, i);
 		if (curseg->segno == segno) {
 			sum = curseg->sum_blk->entries[blkoff];
 			break;
 		}
 	}
 	if (i > CURSEG_COLD_DATA) {
 		struct page *sum_page = get_sum_page(sbi, segno);
 		struct f2fs_summary_block *sum_node;
 		kaddr = page_address(sum_page);
 		sum_node = (struct f2fs_summary_block *)kaddr;
 		sum = sum_node->entries[blkoff];
 		f2fs_put_page(sum_page, 1);
 	}

 	/* Use the locked dnode page and inode */
 	nid = le32_to_cpu(sum.nid);
 	if (dn->inode->i_ino == nid) {
 		struct dnode_of_data tdn = *dn;
 		tdn.nid = nid;
 		tdn.node_page = dn->inode_page;
 		tdn.ofs_in_node = le16_to_cpu(sum.ofs_in_node);
 		truncate_data_blocks_range(&tdn, 1);
 		return 0;
 	} else if (dn->nid == nid) {
 		struct dnode_of_data tdn = *dn;
 		tdn.ofs_in_node = le16_to_cpu(sum.ofs_in_node);
 		truncate_data_blocks_range(&tdn, 1);
 		return 0;
 	}

 	/* Get the node page */
 	node_page = get_node_page(sbi, nid);
 	if (IS_ERR(node_page))
 		return PTR_ERR(node_page);
 	bidx = start_bidx_of_node(ofs_of_node(node_page)) +
 					le16_to_cpu(sum.ofs_in_node);
 	ino = ino_of_node(node_page);
 	f2fs_put_page(node_page, 1);

 	/* Deallocate previous index in the node page */
 	inode = f2fs_iget(sbi->sb, ino);
 	if (IS_ERR(inode))
 		return PTR_ERR(inode);

 	truncate_hole(inode, bidx, bidx + 1);
 	iput(inode);
 	return 0;
 }

 static int do_recover_data(struct f2fs_sb_info *sbi, struct inode *inode,
 					struct page *page, block_t blkaddr)
 {
 	unsigned int start, end;
 	struct dnode_of_data dn;
 	struct f2fs_summary sum;
 	struct node_info ni;
 	int err = 0, recovered = 0;
 	int ilock;

 	start = start_bidx_of_node(ofs_of_node(page));
 	if (IS_INODE(page))
 		end = start + ADDRS_PER_INODE;
 	else
 		end = start + ADDRS_PER_BLOCK;

 	ilock = mutex_lock_op(sbi);
 	set_new_dnode(&dn, inode, NULL, NULL, 0);

 	err = get_dnode_of_data(&dn, start, ALLOC_NODE);
 	if (err) {
 		mutex_unlock_op(sbi, ilock);
 		return err;
 	}

 	wait_on_page_writeback(dn.node_page);

 	get_node_info(sbi, dn.nid, &ni);
 	BUG_ON(ni.ino != ino_of_node(page));
 	BUG_ON(ofs_of_node(dn.node_page) != ofs_of_node(page));

 	for (; start < end; start++) {
 		block_t src, dest;

 		src = datablock_addr(dn.node_page, dn.ofs_in_node);
 		dest = datablock_addr(page, dn.ofs_in_node);

 		if (src != dest && dest != NEW_ADDR && dest != NULL_ADDR) {
 			if (src == NULL_ADDR) {
 				int err = reserve_new_block(&dn);
 				/* We should not get -ENOSPC */
 				BUG_ON(err);
 			}

 			/* Check the previous node page having this index */
 			err = check_index_in_prev_nodes(sbi, dest, &dn);
 			if (err)
 				goto err;

 			set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version);

 			/* write dummy data page */
 			recover_data_page(sbi, NULL, &sum, src, dest);
 			update_extent_cache(dest, &dn);
 			recovered++;
 		}
 		dn.ofs_in_node++;
 	}

 	/* write node page in place */
 	set_summary(&sum, dn.nid, 0, 0);
 	if (IS_INODE(dn.node_page))
 		sync_inode_page(&dn);

 	copy_node_footer(dn.node_page, page);
 	fill_node_footer(dn.node_page, dn.nid, ni.ino,
 					ofs_of_node(page), false);
 	set_page_dirty(dn.node_page);

 	recover_node_page(sbi, dn.node_page, &sum, &ni, blkaddr);
 err:
 	f2fs_put_dnode(&dn);
 	mutex_unlock_op(sbi, ilock);

 	f2fs_msg(sbi->sb, KERN_NOTICE, "recover_data: ino = %lx, "
 			"recovered_data = %d blocks, err = %d",
 			inode->i_ino, recovered, err);
 	return err;
 }

 static int recover_data(struct f2fs_sb_info *sbi,
 				struct list_head *head, int type)
 {
 	unsigned long long cp_ver = le64_to_cpu(sbi->ckpt->checkpoint_ver);
 	struct curseg_info *curseg;
 	struct page *page;
 	int err = 0;
 	block_t blkaddr;

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

 	/* read node page */
 	page = alloc_page(GFP_NOFS | __GFP_ZERO);
 	if (IS_ERR(page))
 		return -ENOMEM;

 	lock_page(page);

 	while (1) {
 		struct fsync_inode_entry *entry;

 		err = f2fs_readpage(sbi, page, blkaddr, READ_SYNC);
 		if (err)
 			goto out;

 		lock_page(page);

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

 		entry = get_fsync_inode(head, ino_of_node(page));
 		if (!entry)
 			goto next;

 		err = do_recover_data(sbi, entry->inode, page, blkaddr);
 		if (err)
 			break;

 		if (entry->blkaddr == blkaddr) {
 			iput(entry->inode);
 			list_del(&entry->list);
 			kmem_cache_free(fsync_entry_slab, entry);
 		}
 next:
 		/* check next segment */
 		blkaddr = next_blkaddr_of_node(page);
 	}
 	unlock_page(page);
 out:
 	__free_pages(page, 0);

 	if (!err)
 		allocate_new_segments(sbi);
 	return err;
 }

 int recover_fsync_data(struct f2fs_sb_info *sbi)
 {
 	struct list_head inode_list;
 	int err;

 	fsync_entry_slab = f2fs_kmem_cache_create("f2fs_fsync_inode_entry",
 			sizeof(struct fsync_inode_entry), NULL);
 	if (unlikely(!fsync_entry_slab))
 		return -ENOMEM;

 	INIT_LIST_HEAD(&inode_list);

 	/* step #1: find fsynced inode numbers */
 	sbi->por_doing = 1;
 	err = find_fsync_dnodes(sbi, &inode_list);
 	if (err)
 		goto out;

 	if (list_empty(&inode_list))
 		goto out;

 	/* step #2: recover data */
 	err = recover_data(sbi, &inode_list, CURSEG_WARM_NODE);
 	BUG_ON(!list_empty(&inode_list));
 out:
 	destroy_fsync_dnodes(&inode_list);
 	kmem_cache_destroy(fsync_entry_slab);
 	sbi->por_doing = 0;
 	if (!err)
 		write_checkpoint(sbi, false);
 	return err;
 }
	/*
	* fs/f2fs/recovery.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/fs.h>
	#include <linux/f2fs_fs.h>
	#include "f2fs.h"
	#include "node.h"
	#include "segment.h"

	static struct kmem_cache *fsync_entry_slab;

	bool space_for_roll_forward(struct f2fs_sb_info *sbi)
	{
	if (sbi->last_valid_block_count + sbi->alloc_valid_block_count
	> sbi->user_block_count)
	return false;
	return true;
	}

	static struct fsync_inode_entry get_fsync_inode(struct list_head head,
	nid_t ino)
	{
	struct list_head *this;
	struct fsync_inode_entry *entry;

	list_for_each(this, head) {
	entry = list_entry(this, struct fsync_inode_entry, list);
	if (entry->inode->i_ino == ino)
	return entry;
	}
	return NULL;
	}

	static int recover_dentry(struct page ipage, struct inode inode)
	{
	void *kaddr = page_address(ipage);
	struct f2fs_node raw_node = (struct f2fs_node )kaddr;
	struct f2fs_inode *raw_inode = &(raw_node->i);
	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 = check_dirty_dir_inode(F2FS_SB(inode->i_sb), pino);
	if (!dir) {
	dir = f2fs_iget(inode->i_sb, pino);
	if (IS_ERR(dir)) {
	err = PTR_ERR(dir);
	goto out;
	}
	set_inode_flag(F2FS_I(dir), FI_DELAY_IPUT);
	add_dirty_dir_inode(dir);
	}

	name.len = le32_to_cpu(raw_inode->i_namelen);
	name.name = raw_inode->i_name;
	retry:
	de = f2fs_find_entry(dir, &name, &page);
	if (de && inode->i_ino == le32_to_cpu(de->ino)) {
	kunmap(page);
	f2fs_put_page(page, 0);
	goto out;
	}
	if (de) {
	einode = f2fs_iget(inode->i_sb, le32_to_cpu(de->ino));
	if (IS_ERR(einode)) {
	WARN_ON(1);
	if (PTR_ERR(einode) == -ENOENT)
	err = -EEXIST;
	goto out;
	}
	f2fs_delete_entry(de, page, einode);
	iput(einode);
	goto retry;
	}
	err = __f2fs_add_link(dir, &name, inode);
	out:
	f2fs_msg(inode->i_sb, KERN_NOTICE, "recover_inode and its dentry: "
	"ino = %x, name = %s, dir = %lx, err = %d",
	ino_of_node(ipage), raw_inode->i_name,
	IS_ERR(dir) ? 0 : dir->i_ino, err);
	return err;
	}

	static int recover_inode(struct inode inode, struct page node_page)
	{
	void *kaddr = page_address(node_page);
	struct f2fs_node raw_node = (struct f2fs_node )kaddr;
	struct f2fs_inode *raw_inode = &(raw_node->i);

	if (!IS_INODE(node_page))
	return 0;

	inode->i_mode = le16_to_cpu(raw_inode->i_mode);
	i_size_write(inode, le64_to_cpu(raw_inode->i_size));
	inode->i_atime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
	inode->i_ctime.tv_sec = le64_to_cpu(raw_inode->i_ctime);
	inode->i_mtime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
	inode->i_atime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);
	inode->i_ctime.tv_nsec = le32_to_cpu(raw_inode->i_ctime_nsec);
	inode->i_mtime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);

	if (is_dent_dnode(node_page))
	return recover_dentry(node_page, inode);

	f2fs_msg(inode->i_sb, KERN_NOTICE, "recover_inode: ino = %x, name = %s",
	ino_of_node(node_page), raw_inode->i_name);
	return 0;
	}

	static int find_fsync_dnodes(struct f2fs_sb_info sbi, struct list_head head)
	{
	unsigned long long cp_ver = le64_to_cpu(sbi->ckpt->checkpoint_ver);
	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 = START_BLOCK(sbi, curseg->segno) + curseg->next_blkoff;

	/* read node page */
	page = alloc_page(GFP_F2FS_ZERO);
	if (IS_ERR(page))
	return PTR_ERR(page);
	lock_page(page);

	while (1) {
	struct fsync_inode_entry *entry;

	err = f2fs_readpage(sbi, page, blkaddr, READ_SYNC);
	if (err)
	goto out;

	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)
	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);
	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)
	break;
	next:
	/* check next segment */
	blkaddr = next_blkaddr_of_node(page);
	}
	unlock_page(page);
	out:
	__free_pages(page, 0);
	return err;
	}

	static void destroy_fsync_dnodes(struct list_head *head)
	{
	struct fsync_inode_entry entry, tmp;

	list_for_each_entry_safe(entry, tmp, head, list) {
	iput(entry->inode);
	list_del(&entry->list);
	kmem_cache_free(fsync_entry_slab, entry);
	}
	}

	static int check_index_in_prev_nodes(struct f2fs_sb_info *sbi,
	block_t blkaddr, struct dnode_of_data *dn)
	{
	struct seg_entry *sentry;
	unsigned int segno = GET_SEGNO(sbi, blkaddr);
	unsigned short blkoff = GET_SEGOFF_FROM_SEG0(sbi, blkaddr) &
	(sbi->blocks_per_seg - 1);
	struct f2fs_summary sum;
	nid_t ino, nid;
	void *kaddr;
	struct inode *inode;
	struct page *node_page;
	block_t bidx;
	int i;

	sentry = get_seg_entry(sbi, segno);
	if (!f2fs_test_bit(blkoff, sentry->cur_valid_map))
	return 0;

	/* Get the previous summary */
	for (i = CURSEG_WARM_DATA; i <= CURSEG_COLD_DATA; i++) {
	struct curseg_info *curseg = CURSEG_I(sbi, i);
	if (curseg->segno == segno) {
	sum = curseg->sum_blk->entries[blkoff];
	break;
	}
	}
	if (i > CURSEG_COLD_DATA) {
	struct page *sum_page = get_sum_page(sbi, segno);
	struct f2fs_summary_block *sum_node;
	kaddr = page_address(sum_page);
	sum_node = (struct f2fs_summary_block *)kaddr;
	sum = sum_node->entries[blkoff];
	f2fs_put_page(sum_page, 1);
	}

	/* Use the locked dnode page and inode */
	nid = le32_to_cpu(sum.nid);
	if (dn->inode->i_ino == nid) {
	struct dnode_of_data tdn = *dn;
	tdn.nid = nid;
	tdn.node_page = dn->inode_page;
	tdn.ofs_in_node = le16_to_cpu(sum.ofs_in_node);
	truncate_data_blocks_range(&tdn, 1);
	return 0;
	} else if (dn->nid == nid) {
	struct dnode_of_data tdn = *dn;
	tdn.ofs_in_node = le16_to_cpu(sum.ofs_in_node);
	truncate_data_blocks_range(&tdn, 1);
	return 0;
	}

	/* Get the node page */
	node_page = get_node_page(sbi, nid);
	if (IS_ERR(node_page))
	return PTR_ERR(node_page);
	bidx = start_bidx_of_node(ofs_of_node(node_page)) +
	le16_to_cpu(sum.ofs_in_node);
	ino = ino_of_node(node_page);
	f2fs_put_page(node_page, 1);

	/* Deallocate previous index in the node page */
	inode = f2fs_iget(sbi->sb, ino);
	if (IS_ERR(inode))
	return PTR_ERR(inode);

	truncate_hole(inode, bidx, bidx + 1);
	iput(inode);
	return 0;
	}

	static int do_recover_data(struct f2fs_sb_info sbi, struct inode inode,
	struct page *page, block_t blkaddr)
	{
	unsigned int start, end;
	struct dnode_of_data dn;
	struct f2fs_summary sum;
	struct node_info ni;
	int err = 0, recovered = 0;
	int ilock;

	start = start_bidx_of_node(ofs_of_node(page));
	if (IS_INODE(page))
	end = start + ADDRS_PER_INODE;
	else
	end = start + ADDRS_PER_BLOCK;

	ilock = mutex_lock_op(sbi);
	set_new_dnode(&dn, inode, NULL, NULL, 0);

	err = get_dnode_of_data(&dn, start, ALLOC_NODE);
	if (err) {
	mutex_unlock_op(sbi, ilock);
	return err;
	}

	wait_on_page_writeback(dn.node_page);

	get_node_info(sbi, dn.nid, &ni);
	BUG_ON(ni.ino != ino_of_node(page));
	BUG_ON(ofs_of_node(dn.node_page) != ofs_of_node(page));

	for (; start < end; start++) {
	block_t src, dest;

	src = datablock_addr(dn.node_page, dn.ofs_in_node);
	dest = datablock_addr(page, dn.ofs_in_node);

	if (src != dest && dest != NEW_ADDR && dest != NULL_ADDR) {
	if (src == NULL_ADDR) {
	int err = reserve_new_block(&dn);
	/* We should not get -ENOSPC */
	BUG_ON(err);
	}

	/* Check the previous node page having this index */
	err = check_index_in_prev_nodes(sbi, dest, &dn);
	if (err)
	goto err;

	set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version);

	/* write dummy data page */
	recover_data_page(sbi, NULL, &sum, src, dest);
	update_extent_cache(dest, &dn);
	recovered++;
	}
	dn.ofs_in_node++;
	}

	/* write node page in place */
	set_summary(&sum, dn.nid, 0, 0);
	if (IS_INODE(dn.node_page))
	sync_inode_page(&dn);

	copy_node_footer(dn.node_page, page);
	fill_node_footer(dn.node_page, dn.nid, ni.ino,
	ofs_of_node(page), false);
	set_page_dirty(dn.node_page);

	recover_node_page(sbi, dn.node_page, &sum, &ni, blkaddr);
	err:
	f2fs_put_dnode(&dn);
	mutex_unlock_op(sbi, ilock);

	f2fs_msg(sbi->sb, KERN_NOTICE, "recover_data: ino = %lx, "
	"recovered_data = %d blocks, err = %d",
	inode->i_ino, recovered, err);
	return err;
	}

	static int recover_data(struct f2fs_sb_info *sbi,
	struct list_head *head, int type)
	{
	unsigned long long cp_ver = le64_to_cpu(sbi->ckpt->checkpoint_ver);
	struct curseg_info *curseg;
	struct page *page;
	int err = 0;
	block_t blkaddr;

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

	/* read node page */
	page = alloc_page(GFP_NOFS \| __GFP_ZERO);
	if (IS_ERR(page))
	return -ENOMEM;

	lock_page(page);

	while (1) {
	struct fsync_inode_entry *entry;

	err = f2fs_readpage(sbi, page, blkaddr, READ_SYNC);
	if (err)
	goto out;

	lock_page(page);

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

	entry = get_fsync_inode(head, ino_of_node(page));
	if (!entry)
	goto next;

	err = do_recover_data(sbi, entry->inode, page, blkaddr);
	if (err)
	break;

	if (entry->blkaddr == blkaddr) {
	iput(entry->inode);
	list_del(&entry->list);
	kmem_cache_free(fsync_entry_slab, entry);
	}
	next:
	/* check next segment */
	blkaddr = next_blkaddr_of_node(page);
	}
	unlock_page(page);
	out:
	__free_pages(page, 0);

	if (!err)
	allocate_new_segments(sbi);
	return err;
	}

	int recover_fsync_data(struct f2fs_sb_info *sbi)
	{
	struct list_head inode_list;
	int err;

	fsync_entry_slab = f2fs_kmem_cache_create("f2fs_fsync_inode_entry",
	sizeof(struct fsync_inode_entry), NULL);
	if (unlikely(!fsync_entry_slab))
	return -ENOMEM;

	INIT_LIST_HEAD(&inode_list);

	/* step #1: find fsynced inode numbers */
	sbi->por_doing = 1;
	err = find_fsync_dnodes(sbi, &inode_list);
	if (err)
	goto out;

	if (list_empty(&inode_list))
	goto out;

	/* step #2: recover data */
	err = recover_data(sbi, &inode_list, CURSEG_WARM_NODE);
	BUG_ON(!list_empty(&inode_list));
	out:
	destroy_fsync_dnodes(&inode_list);
	kmem_cache_destroy(fsync_entry_slab);
	sbi->por_doing = 0;
	if (!err)
	write_checkpoint(sbi, false);
	return err;
	}