fs/f2fs/recovery.c - third_party/kernel - Git at Google

 /*
  * 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"

 /*
  * Roll forward recovery scenarios.
  *
  * [Term] F: fsync_mark, D: dentry_mark
  *
  * 1. inode(x) | CP | inode(x) | dnode(F)
  * -> Update the latest inode(x).
  *
  * 2. inode(x) | CP | inode(F) | dnode(F)
  * -> No problem.
  *
  * 3. inode(x) | CP | dnode(F) | inode(x)
  * -> Recover to the latest dnode(F), and drop the last inode(x)
  *
  * 4. inode(x) | CP | dnode(F) | inode(F)
  * -> No problem.
  *
  * 5. CP | inode(x) | dnode(F)
  * -> The inode(DF) was missing. Should drop this dnode(F).
  *
  * 6. CP | inode(DF) | dnode(F)
  * -> No problem.
  *
  * 7. CP | dnode(F) | inode(DF)
  * -> If f2fs_iget fails, then goto next to find inode(DF).
  *
  * 8. CP | dnode(F) | inode(x)
  * -> If f2fs_iget fails, then goto next to find inode(DF).
  *    But it will fail due to no inode(DF).
  */

 static struct kmem_cache *fsync_entry_slab;

 bool space_for_roll_forward(struct f2fs_sb_info *sbi)
 {
 	s64 nalloc = percpu_counter_sum_positive(&sbi->alloc_valid_block_count);

 	if (sbi->last_valid_block_count + nalloc > sbi->user_block_count)
 		return false;
 	return true;
 }

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

 	list_for_each_entry(entry, head, list)
 		if (entry->inode->i_ino == ino)
 			return entry;

 	return NULL;
 }

 static struct fsync_inode_entry *add_fsync_inode(struct f2fs_sb_info *sbi,
 			struct list_head *head, nid_t ino, bool quota_inode)
 {
 	struct inode *inode;
 	struct fsync_inode_entry *entry;
 	int err;

 	inode = f2fs_iget_retry(sbi->sb, ino);
 	if (IS_ERR(inode))
 		return ERR_CAST(inode);

 	err = dquot_initialize(inode);
 	if (err)
 		goto err_out;

 	if (quota_inode) {
 		err = dquot_alloc_inode(inode);
 		if (err)
 			goto err_out;
 	}

 	entry = f2fs_kmem_cache_alloc(fsync_entry_slab, GFP_F2FS_ZERO);
 	entry->inode = inode;
 	list_add_tail(&entry->list, head);

 	return entry;
 err_out:
 	iput(inode);
 	return ERR_PTR(err);
 }

 static void del_fsync_inode(struct fsync_inode_entry *entry)
 {
 	iput(entry->inode);
 	list_del(&entry->list);
 	kmem_cache_free(fsync_entry_slab, entry);
 }

 static int recover_dentry(struct inode *inode, struct page *ipage,
 						struct list_head *dir_list)
 {
 	struct f2fs_inode *raw_inode = F2FS_INODE(ipage);
 	nid_t pino = le32_to_cpu(raw_inode->i_pino);
 	struct f2fs_dir_entry *de;
 	struct fscrypt_name fname;
 	struct page *page;
 	struct inode *dir, *einode;
 	struct fsync_inode_entry *entry;
 	int err = 0;
 	char *name;

 	entry = get_fsync_inode(dir_list, pino);
 	if (!entry) {
 		entry = add_fsync_inode(F2FS_I_SB(inode), dir_list,
 							pino, false);
 		if (IS_ERR(entry)) {
 			dir = ERR_CAST(entry);
 			err = PTR_ERR(entry);
 			goto out;
 		}
 	}

 	dir = entry->inode;

 	memset(&fname, 0, sizeof(struct fscrypt_name));
 	fname.disk_name.len = le32_to_cpu(raw_inode->i_namelen);
 	fname.disk_name.name = raw_inode->i_name;

 	if (unlikely(fname.disk_name.len > F2FS_NAME_LEN)) {
 		WARN_ON(1);
 		err = -ENAMETOOLONG;
 		goto out;
 	}
 retry:
 	de = __f2fs_find_entry(dir, &fname, &page);
 	if (de && inode->i_ino == le32_to_cpu(de->ino))
 		goto out_unmap_put;

 	if (de) {
 		einode = f2fs_iget_retry(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 = dquot_initialize(einode);
 		if (err) {
 			iput(einode);
 			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;
 	} else if (IS_ERR(page)) {
 		err = PTR_ERR(page);
 	} else {
 		err = __f2fs_do_add_link(dir, &fname, inode,
 					inode->i_ino, inode->i_mode);
 	}
 	if (err == -ENOMEM)
 		goto retry;
 	goto out;

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

 static void recover_inode(struct inode *inode, struct page *page)
 {
 	struct f2fs_inode *raw = F2FS_INODE(page);
 	char *name;

 	inode->i_mode = le16_to_cpu(raw->i_mode);
 	i_uid_write(inode, le32_to_cpu(raw->i_uid));
 	i_gid_write(inode, le32_to_cpu(raw->i_gid));

 	if (raw->i_inline & F2FS_EXTRA_ATTR) {
 		if (f2fs_sb_has_project_quota(F2FS_I_SB(inode)->sb) &&
 			F2FS_FITS_IN_INODE(raw, le16_to_cpu(raw->i_extra_isize),
 								i_projid)) {
 			projid_t i_projid;

 			i_projid = (projid_t)le32_to_cpu(raw->i_projid);
 			F2FS_I(inode)->i_projid =
 				make_kprojid(&init_user_ns, i_projid);
 		}
 	}

 	f2fs_i_size_write(inode, le64_to_cpu(raw->i_size));
 	inode->i_atime.tv_sec = le64_to_cpu(raw->i_atime);
 	inode->i_ctime.tv_sec = le64_to_cpu(raw->i_ctime);
 	inode->i_mtime.tv_sec = le64_to_cpu(raw->i_mtime);
 	inode->i_atime.tv_nsec = le32_to_cpu(raw->i_atime_nsec);
 	inode->i_ctime.tv_nsec = le32_to_cpu(raw->i_ctime_nsec);
 	inode->i_mtime.tv_nsec = le32_to_cpu(raw->i_mtime_nsec);

 	F2FS_I(inode)->i_advise = raw->i_advise;
 	F2FS_I(inode)->i_flags = le32_to_cpu(raw->i_flags);

 	f2fs_mark_inode_dirty_sync(inode, true);

 	if (file_enc_name(inode))
 		name = "<encrypted>";
 	else
 		name = F2FS_INODE(page)->i_name;

 	f2fs_msg(inode->i_sb, KERN_NOTICE, "recover_inode: ino = %x, name = %s",
 			ino_of_node(page), name);
 }

 static int find_fsync_dnodes(struct f2fs_sb_info *sbi, struct list_head *head,
 				bool check_only)
 {
 	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);

 	while (1) {
 		struct fsync_inode_entry *entry;

 		if (!f2fs_is_valid_blkaddr(sbi, blkaddr, META_POR))
 			return 0;

 		page = get_tmp_page(sbi, blkaddr);

 		if (!is_recoverable_dnode(page))
 			break;

 		if (!is_fsync_dnode(page))
 			goto next;

 		entry = get_fsync_inode(head, ino_of_node(page));
 		if (!entry) {
 			bool quota_inode = false;

 			if (!check_only &&
 					IS_INODE(page) && is_dent_dnode(page)) {
 				err = recover_inode_page(sbi, page);
 				if (err)
 					break;
 				quota_inode = true;
 			}

 			/*
 			 * CP | dnode(F) | inode(DF)
 			 * For this case, we should not give up now.
 			 */
 			entry = add_fsync_inode(sbi, head, ino_of_node(page),
 								quota_inode);
 			if (IS_ERR(entry)) {
 				err = PTR_ERR(entry);
 				if (err == -ENOENT) {
 					err = 0;
 					goto next;
 				}
 				break;
 			}
 		}
 		entry->blkaddr = blkaddr;

 		if (IS_INODE(page) && 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;
 }

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

 	list_for_each_entry_safe(entry, tmp, head, list)
 		del_fsync_inode(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_BLKOFF_FROM_SEG0(sbi, blkaddr);
 	struct f2fs_summary_block *sum_node;
 	struct f2fs_summary sum;
 	struct page *sum_page, *node_page;
 	struct dnode_of_data tdn = *dn;
 	nid_t ino, nid;
 	struct inode *inode;
 	unsigned int offset;
 	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_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
 		struct curseg_info *curseg = CURSEG_I(sbi, i);
 		if (curseg->segno == segno) {
 			sum = curseg->sum_blk->entries[blkoff];
 			goto got_it;
 		}
 	}

 	sum_page = get_sum_page(sbi, segno);
 	sum_node = (struct f2fs_summary_block *)page_address(sum_page);
 	sum = sum_node->entries[blkoff];
 	f2fs_put_page(sum_page, 1);
 got_it:
 	/* Use the locked dnode page and inode */
 	nid = le32_to_cpu(sum.nid);
 	if (dn->inode->i_ino == nid) {
 		tdn.nid = nid;
 		if (!dn->inode_page_locked)
 			lock_page(dn->inode_page);
 		tdn.node_page = dn->inode_page;
 		tdn.ofs_in_node = le16_to_cpu(sum.ofs_in_node);
 		goto truncate_out;
 	} else if (dn->nid == nid) {
 		tdn.ofs_in_node = le16_to_cpu(sum.ofs_in_node);
 		goto truncate_out;
 	}

 	/* Get the node page */
 	node_page = get_node_page(sbi, nid);
 	if (IS_ERR(node_page))
 		return PTR_ERR(node_page);

 	offset = ofs_of_node(node_page);
 	ino = ino_of_node(node_page);
 	f2fs_put_page(node_page, 1);

 	if (ino != dn->inode->i_ino) {
 		int ret;

 		/* Deallocate previous index in the node page */
 		inode = f2fs_iget_retry(sbi->sb, ino);
 		if (IS_ERR(inode))
 			return PTR_ERR(inode);

 		ret = dquot_initialize(inode);
 		if (ret) {
 			iput(inode);
 			return ret;
 		}
 	} else {
 		inode = dn->inode;
 	}

 	bidx = start_bidx_of_node(offset, inode) + le16_to_cpu(sum.ofs_in_node);

 	/*
 	 * if inode page is locked, unlock temporarily, but its reference
 	 * count keeps alive.
 	 */
 	if (ino == dn->inode->i_ino && dn->inode_page_locked)
 		unlock_page(dn->inode_page);

 	set_new_dnode(&tdn, inode, NULL, NULL, 0);
 	if (get_dnode_of_data(&tdn, bidx, LOOKUP_NODE))
 		goto out;

 	if (tdn.data_blkaddr == blkaddr)
 		truncate_data_blocks_range(&tdn, 1);

 	f2fs_put_dnode(&tdn);
 out:
 	if (ino != dn->inode->i_ino)
 		iput(inode);
 	else if (dn->inode_page_locked)
 		lock_page(dn->inode_page);
 	return 0;

 truncate_out:
 	if (datablock_addr(tdn.inode, tdn.node_page,
 					tdn.ofs_in_node) == blkaddr)
 		truncate_data_blocks_range(&tdn, 1);
 	if (dn->inode->i_ino == nid && !dn->inode_page_locked)
 		unlock_page(dn->inode_page);
 	return 0;
 }

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

 	/* step 1: recover xattr */
 	if (IS_INODE(page)) {
 		recover_inline_xattr(inode, page);
 	} else if (f2fs_has_xattr_block(ofs_of_node(page))) {
 		err = recover_xattr_data(inode, page, blkaddr);
 		if (!err)
 			recovered++;
 		goto out;
 	}

 	/* step 2: recover inline data */
 	if (recover_inline_data(inode, page))
 		goto out;

 	/* step 3: recover data indices */
 	start = start_bidx_of_node(ofs_of_node(page), inode);
 	end = start + ADDRS_PER_PAGE(page, inode);

 	set_new_dnode(&dn, inode, NULL, NULL, 0);
 retry_dn:
 	err = get_dnode_of_data(&dn, start, ALLOC_NODE);
 	if (err) {
 		if (err == -ENOMEM) {
 			congestion_wait(BLK_RW_ASYNC, HZ/50);
 			goto retry_dn;
 		}
 		goto out;
 	}

 	f2fs_wait_on_page_writeback(dn.node_page, NODE, true);

 	get_node_info(sbi, dn.nid, &ni);
 	f2fs_bug_on(sbi, ni.ino != ino_of_node(page));

 	if (ofs_of_node(dn.node_page) != ofs_of_node(page)) {
 		f2fs_msg(sbi->sb, KERN_WARNING,
 			"Inconsistent ofs_of_node, ino:%lu, ofs:%u, %u",
 			inode->i_ino, ofs_of_node(dn.node_page),
 			ofs_of_node(page));
 		err = -EFSCORRUPTED;
 		goto err;
 	}

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

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

 		/* skip recovering if dest is the same as src */
 		if (src == dest)
 			continue;

 		/* dest is invalid, just invalidate src block */
 		if (dest == NULL_ADDR) {
 			truncate_data_blocks_range(&dn, 1);
 			continue;
 		}

 		if (!file_keep_isize(inode) &&
 			(i_size_read(inode) <= ((loff_t)start << PAGE_SHIFT)))
 			f2fs_i_size_write(inode,
 				(loff_t)(start + 1) << PAGE_SHIFT);

 		/*
 		 * dest is reserved block, invalidate src block
 		 * and then reserve one new block in dnode page.
 		 */
 		if (dest == NEW_ADDR) {
 			truncate_data_blocks_range(&dn, 1);
 			reserve_new_block(&dn);
 			continue;
 		}

 		/* dest is valid block, try to recover from src to dest */
 		if (f2fs_is_valid_blkaddr(sbi, dest, META_POR)) {

 			if (src == NULL_ADDR) {
 				err = reserve_new_block(&dn);
 #ifdef CONFIG_F2FS_FAULT_INJECTION
 				while (err)
 					err = reserve_new_block(&dn);
 #endif
 				/* We should not get -ENOSPC */
 				f2fs_bug_on(sbi, err);
 				if (err)
 					goto err;
 			}
 retry_prev:
 			/* Check the previous node page having this index */
 			err = check_index_in_prev_nodes(sbi, dest, &dn);
 			if (err) {
 				if (err == -ENOMEM) {
 					congestion_wait(BLK_RW_ASYNC, HZ/50);
 					goto retry_prev;
 				}
 				goto err;
 			}

 			/* write dummy data page */
 			f2fs_replace_block(sbi, &dn, src, dest,
 						ni.version, false, false);
 			recovered++;
 		}
 	}

 	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);
 err:
 	f2fs_put_dnode(&dn);
 out:
 	f2fs_msg(sbi->sb, KERN_NOTICE,
 		"recover_data: ino = %lx (i_size: %s) recovered = %d, err = %d",
 		inode->i_ino,
 		file_keep_isize(inode) ? "keep" : "recover",
 		recovered, err);
 	return err;
 }

 static int recover_data(struct f2fs_sb_info *sbi, struct list_head *inode_list,
 						struct list_head *dir_list)
 {
 	struct curseg_info *curseg;
 	struct page *page = NULL;
 	int err = 0;
 	block_t blkaddr;

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

 	while (1) {
 		struct fsync_inode_entry *entry;

 		if (!f2fs_is_valid_blkaddr(sbi, blkaddr, META_POR))
 			break;

 		ra_meta_pages_cond(sbi, blkaddr);

 		page = get_tmp_page(sbi, blkaddr);

 		if (!is_recoverable_dnode(page)) {
 			f2fs_put_page(page, 1);
 			break;
 		}

 		entry = get_fsync_inode(inode_list, ino_of_node(page));
 		if (!entry)
 			goto next;
 		/*
 		 * inode(x) | CP | inode(x) | dnode(F)
 		 * In this case, we can lose the latest inode(x).
 		 * So, call recover_inode for the inode update.
 		 */
 		if (IS_INODE(page))
 			recover_inode(entry->inode, page);
 		if (entry->last_dentry == blkaddr) {
 			err = recover_dentry(entry->inode, page, dir_list);
 			if (err) {
 				f2fs_put_page(page, 1);
 				break;
 			}
 		}
 		err = do_recover_data(sbi, entry->inode, page, blkaddr);
 		if (err) {
 			f2fs_put_page(page, 1);
 			break;
 		}

 		if (entry->blkaddr == blkaddr)
 			del_fsync_inode(entry);
 next:
 		/* check next segment */
 		blkaddr = next_blkaddr_of_node(page);
 		f2fs_put_page(page, 1);
 	}
 	if (!err)
 		allocate_new_segments(sbi);
 	return err;
 }

 int recover_fsync_data(struct f2fs_sb_info *sbi, bool check_only)
 {
 	struct list_head inode_list;
 	struct list_head dir_list;
 	int err;
 	int ret = 0;
 	unsigned long s_flags = sbi->sb->s_flags;
 	bool need_writecp = false;

 	if (s_flags & MS_RDONLY) {
 		f2fs_msg(sbi->sb, KERN_INFO, "orphan cleanup on readonly fs");
 		sbi->sb->s_flags &= ~MS_RDONLY;
 	}

 #ifdef CONFIG_QUOTA
 	/* Needed for iput() to work correctly and not trash data */
 	sbi->sb->s_flags |= MS_ACTIVE;
 	/* Turn on quotas so that they are updated correctly */
 	f2fs_enable_quota_files(sbi);
 #endif

 	fsync_entry_slab = f2fs_kmem_cache_create("f2fs_fsync_inode_entry",
 			sizeof(struct fsync_inode_entry));
 	if (!fsync_entry_slab) {
 		err = -ENOMEM;
 		goto out;
 	}

 	INIT_LIST_HEAD(&inode_list);
 	INIT_LIST_HEAD(&dir_list);

 	/* prevent checkpoint */
 	mutex_lock(&sbi->cp_mutex);

 	/* step #1: find fsynced inode numbers */
 	err = find_fsync_dnodes(sbi, &inode_list, check_only);
 	if (err || list_empty(&inode_list))
 		goto skip;

 	if (check_only) {
 		ret = 1;
 		goto skip;
 	}

 	need_writecp = true;

 	/* step #2: recover data */
 	err = recover_data(sbi, &inode_list, &dir_list);
 	if (!err)
 		f2fs_bug_on(sbi, !list_empty(&inode_list));
 skip:
 	destroy_fsync_dnodes(&inode_list);

 	/* truncate meta pages to be used by the recovery */
 	truncate_inode_pages_range(META_MAPPING(sbi),
 			(loff_t)MAIN_BLKADDR(sbi) << PAGE_SHIFT, -1);

 	if (err) {
 		truncate_inode_pages_final(NODE_MAPPING(sbi));
 		truncate_inode_pages_final(META_MAPPING(sbi));
 	}

 	clear_sbi_flag(sbi, SBI_POR_DOING);
 	mutex_unlock(&sbi->cp_mutex);

 	/* let's drop all the directory inodes for clean checkpoint */
 	destroy_fsync_dnodes(&dir_list);

 	if (!err && need_writecp) {
 		struct cp_control cpc = {
 			.reason = CP_RECOVERY,
 		};
 		err = write_checkpoint(sbi, &cpc);
 	}

 	kmem_cache_destroy(fsync_entry_slab);
 out:
 #ifdef CONFIG_QUOTA
 	/* Turn quotas off */
 	f2fs_quota_off_umount(sbi->sb);
 #endif
 	sbi->sb->s_flags = s_flags; /* Restore MS_RDONLY status */

 	return ret ? ret: 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"

	/*
	* Roll forward recovery scenarios.
	*
	* [Term] F: fsync_mark, D: dentry_mark
	*
	* 1. inode(x) \| CP \| inode(x) \| dnode(F)
	* -> Update the latest inode(x).
	*
	* 2. inode(x) \| CP \| inode(F) \| dnode(F)
	* -> No problem.
	*
	* 3. inode(x) \| CP \| dnode(F) \| inode(x)
	* -> Recover to the latest dnode(F), and drop the last inode(x)
	*
	* 4. inode(x) \| CP \| dnode(F) \| inode(F)
	* -> No problem.
	*
	* 5. CP \| inode(x) \| dnode(F)
	* -> The inode(DF) was missing. Should drop this dnode(F).
	*
	* 6. CP \| inode(DF) \| dnode(F)
	* -> No problem.
	*
	* 7. CP \| dnode(F) \| inode(DF)
	* -> If f2fs_iget fails, then goto next to find inode(DF).
	*
	* 8. CP \| dnode(F) \| inode(x)
	* -> If f2fs_iget fails, then goto next to find inode(DF).
	* But it will fail due to no inode(DF).
	*/

	static struct kmem_cache *fsync_entry_slab;

	bool space_for_roll_forward(struct f2fs_sb_info *sbi)
	{
	s64 nalloc = percpu_counter_sum_positive(&sbi->alloc_valid_block_count);

	if (sbi->last_valid_block_count + nalloc > sbi->user_block_count)
	return false;
	return true;
	}

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

	list_for_each_entry(entry, head, list)
	if (entry->inode->i_ino == ino)
	return entry;

	return NULL;
	}

	static struct fsync_inode_entry add_fsync_inode(struct f2fs_sb_info sbi,
	struct list_head *head, nid_t ino, bool quota_inode)
	{
	struct inode *inode;
	struct fsync_inode_entry *entry;
	int err;

	inode = f2fs_iget_retry(sbi->sb, ino);
	if (IS_ERR(inode))
	return ERR_CAST(inode);

	err = dquot_initialize(inode);
	if (err)
	goto err_out;

	if (quota_inode) {
	err = dquot_alloc_inode(inode);
	if (err)
	goto err_out;
	}

	entry = f2fs_kmem_cache_alloc(fsync_entry_slab, GFP_F2FS_ZERO);
	entry->inode = inode;
	list_add_tail(&entry->list, head);

	return entry;
	err_out:
	iput(inode);
	return ERR_PTR(err);
	}

	static void del_fsync_inode(struct fsync_inode_entry *entry)
	{
	iput(entry->inode);
	list_del(&entry->list);
	kmem_cache_free(fsync_entry_slab, entry);
	}

	static int recover_dentry(struct inode inode, struct page ipage,
	struct list_head *dir_list)
	{
	struct f2fs_inode *raw_inode = F2FS_INODE(ipage);
	nid_t pino = le32_to_cpu(raw_inode->i_pino);
	struct f2fs_dir_entry *de;
	struct fscrypt_name fname;
	struct page *page;
	struct inode dir, einode;
	struct fsync_inode_entry *entry;
	int err = 0;
	char *name;

	entry = get_fsync_inode(dir_list, pino);
	if (!entry) {
	entry = add_fsync_inode(F2FS_I_SB(inode), dir_list,
	pino, false);
	if (IS_ERR(entry)) {
	dir = ERR_CAST(entry);
	err = PTR_ERR(entry);
	goto out;
	}
	}

	dir = entry->inode;

	memset(&fname, 0, sizeof(struct fscrypt_name));
	fname.disk_name.len = le32_to_cpu(raw_inode->i_namelen);
	fname.disk_name.name = raw_inode->i_name;

	if (unlikely(fname.disk_name.len > F2FS_NAME_LEN)) {
	WARN_ON(1);
	err = -ENAMETOOLONG;
	goto out;
	}
	retry:
	de = __f2fs_find_entry(dir, &fname, &page);
	if (de && inode->i_ino == le32_to_cpu(de->ino))
	goto out_unmap_put;

	if (de) {
	einode = f2fs_iget_retry(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 = dquot_initialize(einode);
	if (err) {
	iput(einode);
	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;
	} else if (IS_ERR(page)) {
	err = PTR_ERR(page);
	} else {
	err = __f2fs_do_add_link(dir, &fname, inode,
	inode->i_ino, inode->i_mode);
	}
	if (err == -ENOMEM)
	goto retry;
	goto out;

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

	static void recover_inode(struct inode inode, struct page page)
	{
	struct f2fs_inode *raw = F2FS_INODE(page);
	char *name;

	inode->i_mode = le16_to_cpu(raw->i_mode);
	i_uid_write(inode, le32_to_cpu(raw->i_uid));
	i_gid_write(inode, le32_to_cpu(raw->i_gid));

	if (raw->i_inline & F2FS_EXTRA_ATTR) {
	if (f2fs_sb_has_project_quota(F2FS_I_SB(inode)->sb) &&
	F2FS_FITS_IN_INODE(raw, le16_to_cpu(raw->i_extra_isize),
	i_projid)) {
	projid_t i_projid;

	i_projid = (projid_t)le32_to_cpu(raw->i_projid);
	F2FS_I(inode)->i_projid =
	make_kprojid(&init_user_ns, i_projid);
	}
	}

	f2fs_i_size_write(inode, le64_to_cpu(raw->i_size));
	inode->i_atime.tv_sec = le64_to_cpu(raw->i_atime);
	inode->i_ctime.tv_sec = le64_to_cpu(raw->i_ctime);
	inode->i_mtime.tv_sec = le64_to_cpu(raw->i_mtime);
	inode->i_atime.tv_nsec = le32_to_cpu(raw->i_atime_nsec);
	inode->i_ctime.tv_nsec = le32_to_cpu(raw->i_ctime_nsec);
	inode->i_mtime.tv_nsec = le32_to_cpu(raw->i_mtime_nsec);

	F2FS_I(inode)->i_advise = raw->i_advise;
	F2FS_I(inode)->i_flags = le32_to_cpu(raw->i_flags);

	f2fs_mark_inode_dirty_sync(inode, true);

	if (file_enc_name(inode))
	name = "<encrypted>";
	else
	name = F2FS_INODE(page)->i_name;

	f2fs_msg(inode->i_sb, KERN_NOTICE, "recover_inode: ino = %x, name = %s",
	ino_of_node(page), name);
	}

	static int find_fsync_dnodes(struct f2fs_sb_info sbi, struct list_head head,
	bool check_only)
	{
	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);

	while (1) {
	struct fsync_inode_entry *entry;

	if (!f2fs_is_valid_blkaddr(sbi, blkaddr, META_POR))
	return 0;

	page = get_tmp_page(sbi, blkaddr);

	if (!is_recoverable_dnode(page))
	break;

	if (!is_fsync_dnode(page))
	goto next;

	entry = get_fsync_inode(head, ino_of_node(page));
	if (!entry) {
	bool quota_inode = false;

	if (!check_only &&
	IS_INODE(page) && is_dent_dnode(page)) {
	err = recover_inode_page(sbi, page);
	if (err)
	break;
	quota_inode = true;
	}

	/*
	* CP \| dnode(F) \| inode(DF)
	* For this case, we should not give up now.
	*/
	entry = add_fsync_inode(sbi, head, ino_of_node(page),
	quota_inode);
	if (IS_ERR(entry)) {
	err = PTR_ERR(entry);
	if (err == -ENOENT) {
	err = 0;
	goto next;
	}
	break;
	}
	}
	entry->blkaddr = blkaddr;

	if (IS_INODE(page) && 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;
	}

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

	list_for_each_entry_safe(entry, tmp, head, list)
	del_fsync_inode(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_BLKOFF_FROM_SEG0(sbi, blkaddr);
	struct f2fs_summary_block *sum_node;
	struct f2fs_summary sum;
	struct page sum_page, node_page;
	struct dnode_of_data tdn = *dn;
	nid_t ino, nid;
	struct inode *inode;
	unsigned int offset;
	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_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
	struct curseg_info *curseg = CURSEG_I(sbi, i);
	if (curseg->segno == segno) {
	sum = curseg->sum_blk->entries[blkoff];
	goto got_it;
	}
	}

	sum_page = get_sum_page(sbi, segno);
	sum_node = (struct f2fs_summary_block *)page_address(sum_page);
	sum = sum_node->entries[blkoff];
	f2fs_put_page(sum_page, 1);
	got_it:
	/* Use the locked dnode page and inode */
	nid = le32_to_cpu(sum.nid);
	if (dn->inode->i_ino == nid) {
	tdn.nid = nid;
	if (!dn->inode_page_locked)
	lock_page(dn->inode_page);
	tdn.node_page = dn->inode_page;
	tdn.ofs_in_node = le16_to_cpu(sum.ofs_in_node);
	goto truncate_out;
	} else if (dn->nid == nid) {
	tdn.ofs_in_node = le16_to_cpu(sum.ofs_in_node);
	goto truncate_out;
	}

	/* Get the node page */
	node_page = get_node_page(sbi, nid);
	if (IS_ERR(node_page))
	return PTR_ERR(node_page);

	offset = ofs_of_node(node_page);
	ino = ino_of_node(node_page);
	f2fs_put_page(node_page, 1);

	if (ino != dn->inode->i_ino) {
	int ret;

	/* Deallocate previous index in the node page */
	inode = f2fs_iget_retry(sbi->sb, ino);
	if (IS_ERR(inode))
	return PTR_ERR(inode);

	ret = dquot_initialize(inode);
	if (ret) {
	iput(inode);
	return ret;
	}
	} else {
	inode = dn->inode;
	}

	bidx = start_bidx_of_node(offset, inode) + le16_to_cpu(sum.ofs_in_node);

	/*
	* if inode page is locked, unlock temporarily, but its reference
	* count keeps alive.
	*/
	if (ino == dn->inode->i_ino && dn->inode_page_locked)
	unlock_page(dn->inode_page);

	set_new_dnode(&tdn, inode, NULL, NULL, 0);
	if (get_dnode_of_data(&tdn, bidx, LOOKUP_NODE))
	goto out;

	if (tdn.data_blkaddr == blkaddr)
	truncate_data_blocks_range(&tdn, 1);

	f2fs_put_dnode(&tdn);
	out:
	if (ino != dn->inode->i_ino)
	iput(inode);
	else if (dn->inode_page_locked)
	lock_page(dn->inode_page);
	return 0;

	truncate_out:
	if (datablock_addr(tdn.inode, tdn.node_page,
	tdn.ofs_in_node) == blkaddr)
	truncate_data_blocks_range(&tdn, 1);
	if (dn->inode->i_ino == nid && !dn->inode_page_locked)
	unlock_page(dn->inode_page);
	return 0;
	}

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

	/* step 1: recover xattr */
	if (IS_INODE(page)) {
	recover_inline_xattr(inode, page);
	} else if (f2fs_has_xattr_block(ofs_of_node(page))) {
	err = recover_xattr_data(inode, page, blkaddr);
	if (!err)
	recovered++;
	goto out;
	}

	/* step 2: recover inline data */
	if (recover_inline_data(inode, page))
	goto out;

	/* step 3: recover data indices */
	start = start_bidx_of_node(ofs_of_node(page), inode);
	end = start + ADDRS_PER_PAGE(page, inode);

	set_new_dnode(&dn, inode, NULL, NULL, 0);
	retry_dn:
	err = get_dnode_of_data(&dn, start, ALLOC_NODE);
	if (err) {
	if (err == -ENOMEM) {
	congestion_wait(BLK_RW_ASYNC, HZ/50);
	goto retry_dn;
	}
	goto out;
	}

	f2fs_wait_on_page_writeback(dn.node_page, NODE, true);

	get_node_info(sbi, dn.nid, &ni);
	f2fs_bug_on(sbi, ni.ino != ino_of_node(page));

	if (ofs_of_node(dn.node_page) != ofs_of_node(page)) {
	f2fs_msg(sbi->sb, KERN_WARNING,
	"Inconsistent ofs_of_node, ino:%lu, ofs:%u, %u",
	inode->i_ino, ofs_of_node(dn.node_page),
	ofs_of_node(page));
	err = -EFSCORRUPTED;
	goto err;
	}

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

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

	/* skip recovering if dest is the same as src */
	if (src == dest)
	continue;

	/* dest is invalid, just invalidate src block */
	if (dest == NULL_ADDR) {
	truncate_data_blocks_range(&dn, 1);
	continue;
	}

	if (!file_keep_isize(inode) &&
	(i_size_read(inode) <= ((loff_t)start << PAGE_SHIFT)))
	f2fs_i_size_write(inode,
	(loff_t)(start + 1) << PAGE_SHIFT);

	/*
	* dest is reserved block, invalidate src block
	* and then reserve one new block in dnode page.
	*/
	if (dest == NEW_ADDR) {
	truncate_data_blocks_range(&dn, 1);
	reserve_new_block(&dn);
	continue;
	}

	/* dest is valid block, try to recover from src to dest */
	if (f2fs_is_valid_blkaddr(sbi, dest, META_POR)) {

	if (src == NULL_ADDR) {
	err = reserve_new_block(&dn);
	#ifdef CONFIG_F2FS_FAULT_INJECTION
	while (err)
	err = reserve_new_block(&dn);
	#endif
	/* We should not get -ENOSPC */
	f2fs_bug_on(sbi, err);
	if (err)
	goto err;
	}
	retry_prev:
	/* Check the previous node page having this index */
	err = check_index_in_prev_nodes(sbi, dest, &dn);
	if (err) {
	if (err == -ENOMEM) {
	congestion_wait(BLK_RW_ASYNC, HZ/50);
	goto retry_prev;
	}
	goto err;
	}

	/* write dummy data page */
	f2fs_replace_block(sbi, &dn, src, dest,
	ni.version, false, false);
	recovered++;
	}
	}

	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);
	err:
	f2fs_put_dnode(&dn);
	out:
	f2fs_msg(sbi->sb, KERN_NOTICE,
	"recover_data: ino = %lx (i_size: %s) recovered = %d, err = %d",
	inode->i_ino,
	file_keep_isize(inode) ? "keep" : "recover",
	recovered, err);
	return err;
	}

	static int recover_data(struct f2fs_sb_info sbi, struct list_head inode_list,
	struct list_head *dir_list)
	{
	struct curseg_info *curseg;
	struct page *page = NULL;
	int err = 0;
	block_t blkaddr;

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

	while (1) {
	struct fsync_inode_entry *entry;

	if (!f2fs_is_valid_blkaddr(sbi, blkaddr, META_POR))
	break;

	ra_meta_pages_cond(sbi, blkaddr);

	page = get_tmp_page(sbi, blkaddr);

	if (!is_recoverable_dnode(page)) {
	f2fs_put_page(page, 1);
	break;
	}

	entry = get_fsync_inode(inode_list, ino_of_node(page));
	if (!entry)
	goto next;
	/*
	* inode(x) \| CP \| inode(x) \| dnode(F)
	* In this case, we can lose the latest inode(x).
	* So, call recover_inode for the inode update.
	*/
	if (IS_INODE(page))
	recover_inode(entry->inode, page);
	if (entry->last_dentry == blkaddr) {
	err = recover_dentry(entry->inode, page, dir_list);
	if (err) {
	f2fs_put_page(page, 1);
	break;
	}
	}
	err = do_recover_data(sbi, entry->inode, page, blkaddr);
	if (err) {
	f2fs_put_page(page, 1);
	break;
	}

	if (entry->blkaddr == blkaddr)
	del_fsync_inode(entry);
	next:
	/* check next segment */
	blkaddr = next_blkaddr_of_node(page);
	f2fs_put_page(page, 1);
	}
	if (!err)
	allocate_new_segments(sbi);
	return err;
	}

	int recover_fsync_data(struct f2fs_sb_info *sbi, bool check_only)
	{
	struct list_head inode_list;
	struct list_head dir_list;
	int err;
	int ret = 0;
	unsigned long s_flags = sbi->sb->s_flags;
	bool need_writecp = false;

	if (s_flags & MS_RDONLY) {
	f2fs_msg(sbi->sb, KERN_INFO, "orphan cleanup on readonly fs");
	sbi->sb->s_flags &= ~MS_RDONLY;
	}

	#ifdef CONFIG_QUOTA
	/* Needed for iput() to work correctly and not trash data */
	sbi->sb->s_flags \|= MS_ACTIVE;
	/* Turn on quotas so that they are updated correctly */
	f2fs_enable_quota_files(sbi);
	#endif

	fsync_entry_slab = f2fs_kmem_cache_create("f2fs_fsync_inode_entry",
	sizeof(struct fsync_inode_entry));
	if (!fsync_entry_slab) {
	err = -ENOMEM;
	goto out;
	}

	INIT_LIST_HEAD(&inode_list);
	INIT_LIST_HEAD(&dir_list);

	/* prevent checkpoint */
	mutex_lock(&sbi->cp_mutex);

	/* step #1: find fsynced inode numbers */
	err = find_fsync_dnodes(sbi, &inode_list, check_only);
	if (err \|\| list_empty(&inode_list))
	goto skip;

	if (check_only) {
	ret = 1;
	goto skip;
	}

	need_writecp = true;

	/* step #2: recover data */
	err = recover_data(sbi, &inode_list, &dir_list);
	if (!err)
	f2fs_bug_on(sbi, !list_empty(&inode_list));
	skip:
	destroy_fsync_dnodes(&inode_list);

	/* truncate meta pages to be used by the recovery */
	truncate_inode_pages_range(META_MAPPING(sbi),
	(loff_t)MAIN_BLKADDR(sbi) << PAGE_SHIFT, -1);

	if (err) {
	truncate_inode_pages_final(NODE_MAPPING(sbi));
	truncate_inode_pages_final(META_MAPPING(sbi));
	}

	clear_sbi_flag(sbi, SBI_POR_DOING);
	mutex_unlock(&sbi->cp_mutex);

	/* let's drop all the directory inodes for clean checkpoint */
	destroy_fsync_dnodes(&dir_list);

	if (!err && need_writecp) {
	struct cp_control cpc = {
	.reason = CP_RECOVERY,
	};
	err = write_checkpoint(sbi, &cpc);
	}

	kmem_cache_destroy(fsync_entry_slab);
	out:
	#ifdef CONFIG_QUOTA
	/* Turn quotas off */
	f2fs_quota_off_umount(sbi->sb);
	#endif
	sbi->sb->s_flags = s_flags; /* Restore MS_RDONLY status */

	return ret ? ret: err;
	}