Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 3320 insertions, 0 deletions

diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
new file mode 100644
index 000000000..02cb1c806
--- /dev/null
+++ b/fs/f2fs/node.c
@@ -0,0 +1,3320 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * fs/f2fs/node.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ */
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+#include <linux/mpage.h>
+#include <linux/backing-dev.h>
+#include <linux/blkdev.h>
+#include <linux/pagevec.h>
+#include <linux/swap.h>
+
+#include "f2fs.h"
+#include "node.h"
+#include "segment.h"
+#include "xattr.h"
+#include "trace.h"
+#include <trace/events/f2fs.h>
+
+#define on_f2fs_build_free_nids(nmi) mutex_is_locked(&(nm_i)->build_lock)
+
+static struct kmem_cache *nat_entry_slab;
+static struct kmem_cache *free_nid_slab;
+static struct kmem_cache *nat_entry_set_slab;
+static struct kmem_cache *fsync_node_entry_slab;
+
+/*
+ * Check whether the given nid is within node id range.
+ */
+int f2fs_check_nid_range(struct f2fs_sb_info *sbi, nid_t nid)
+{
+	if (unlikely(nid < F2FS_ROOT_INO(sbi) || nid >= NM_I(sbi)->max_nid)) {
+		set_sbi_flag(sbi, SBI_NEED_FSCK);
+		f2fs_warn(sbi, "%s: out-of-range nid=%x, run fsck to fix.",
+			  __func__, nid);
+		return -EFSCORRUPTED;
+	}
+	return 0;
+}
+
+bool f2fs_available_free_memory(struct f2fs_sb_info *sbi, int type)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct sysinfo val;
+	unsigned long avail_ram;
+	unsigned long mem_size = 0;
+	bool res = false;
+
+	si_meminfo(&val);
+
+	/* only uses low memory */
+	avail_ram = val.totalram - val.totalhigh;
+
+	/*
+	 * give 25%, 25%, 50%, 50%, 50% memory for each components respectively
+	 */
+	if (type == FREE_NIDS) {
+		mem_size = (nm_i->nid_cnt[FREE_NID] *
+				sizeof(struct free_nid)) >> PAGE_SHIFT;
+		res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 2);
+	} else if (type == NAT_ENTRIES) {
+		mem_size = (nm_i->nat_cnt[TOTAL_NAT] *
+				sizeof(struct nat_entry)) >> PAGE_SHIFT;
+		res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 2);
+		if (excess_cached_nats(sbi))
+			res = false;
+	} else if (type == DIRTY_DENTS) {
+		if (sbi->sb->s_bdi->wb.dirty_exceeded)
+			return false;
+		mem_size = get_pages(sbi, F2FS_DIRTY_DENTS);
+		res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 1);
+	} else if (type == INO_ENTRIES) {
+		int i;
+
+		for (i = 0; i < MAX_INO_ENTRY; i++)
+			mem_size += sbi->im[i].ino_num *
+						sizeof(struct ino_entry);
+		mem_size >>= PAGE_SHIFT;
+		res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 1);
+	} else if (type == EXTENT_CACHE) {
+		mem_size = (atomic_read(&sbi->total_ext_tree) *
+				sizeof(struct extent_tree) +
+				atomic_read(&sbi->total_ext_node) *
+				sizeof(struct extent_node)) >> PAGE_SHIFT;
+		res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 1);
+	} else if (type == INMEM_PAGES) {
+		/* it allows 20% / total_ram for inmemory pages */
+		mem_size = get_pages(sbi, F2FS_INMEM_PAGES);
+		res = mem_size < (val.totalram / 5);
+	} else {
+		if (!sbi->sb->s_bdi->wb.dirty_exceeded)
+			return true;
+	}
+	return res;
+}
+
+static void clear_node_page_dirty(struct page *page)
+{
+	if (PageDirty(page)) {
+		f2fs_clear_page_cache_dirty_tag(page);
+		clear_page_dirty_for_io(page);
+		dec_page_count(F2FS_P_SB(page), F2FS_DIRTY_NODES);
+	}
+	ClearPageUptodate(page);
+}
+
+static struct page *get_current_nat_page(struct f2fs_sb_info *sbi, nid_t nid)
+{
+	return f2fs_get_meta_page_retry(sbi, current_nat_addr(sbi, nid));
+}
+
+static struct page *get_next_nat_page(struct f2fs_sb_info *sbi, nid_t nid)
+{
+	struct page *src_page;
+	struct page *dst_page;
+	pgoff_t dst_off;
+	void *src_addr;
+	void *dst_addr;
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+
+	dst_off = next_nat_addr(sbi, current_nat_addr(sbi, nid));
+
+	/* get current nat block page with lock */
+	src_page = get_current_nat_page(sbi, nid);
+	if (IS_ERR(src_page))
+		return src_page;
+	dst_page = f2fs_grab_meta_page(sbi, dst_off);
+	f2fs_bug_on(sbi, PageDirty(src_page));
+
+	src_addr = page_address(src_page);
+	dst_addr = page_address(dst_page);
+	memcpy(dst_addr, src_addr, PAGE_SIZE);
+	set_page_dirty(dst_page);
+	f2fs_put_page(src_page, 1);
+
+	set_to_next_nat(nm_i, nid);
+
+	return dst_page;
+}
+
+static struct nat_entry *__alloc_nat_entry(nid_t nid, bool no_fail)
+{
+	struct nat_entry *new;
+
+	if (no_fail)
+		new = f2fs_kmem_cache_alloc(nat_entry_slab, GFP_F2FS_ZERO);
+	else
+		new = kmem_cache_alloc(nat_entry_slab, GFP_F2FS_ZERO);
+	if (new) {
+		nat_set_nid(new, nid);
+		nat_reset_flag(new);
+	}
+	return new;
+}
+
+static void __free_nat_entry(struct nat_entry *e)
+{
+	kmem_cache_free(nat_entry_slab, e);
+}
+
+/* must be locked by nat_tree_lock */
+static struct nat_entry *__init_nat_entry(struct f2fs_nm_info *nm_i,
+	struct nat_entry *ne, struct f2fs_nat_entry *raw_ne, bool no_fail)
+{
+	if (no_fail)
+		f2fs_radix_tree_insert(&nm_i->nat_root, nat_get_nid(ne), ne);
+	else if (radix_tree_insert(&nm_i->nat_root, nat_get_nid(ne), ne))
+		return NULL;
+
+	if (raw_ne)
+		node_info_from_raw_nat(&ne->ni, raw_ne);
+
+	spin_lock(&nm_i->nat_list_lock);
+	list_add_tail(&ne->list, &nm_i->nat_entries);
+	spin_unlock(&nm_i->nat_list_lock);
+
+	nm_i->nat_cnt[TOTAL_NAT]++;
+	nm_i->nat_cnt[RECLAIMABLE_NAT]++;
+	return ne;
+}
+
+static struct nat_entry *__lookup_nat_cache(struct f2fs_nm_info *nm_i, nid_t n)
+{
+	struct nat_entry *ne;
+
+	ne = radix_tree_lookup(&nm_i->nat_root, n);
+
+	/* for recent accessed nat entry, move it to tail of lru list */
+	if (ne && !get_nat_flag(ne, IS_DIRTY)) {
+		spin_lock(&nm_i->nat_list_lock);
+		if (!list_empty(&ne->list))
+			list_move_tail(&ne->list, &nm_i->nat_entries);
+		spin_unlock(&nm_i->nat_list_lock);
+	}
+
+	return ne;
+}
+
+static unsigned int __gang_lookup_nat_cache(struct f2fs_nm_info *nm_i,
+		nid_t start, unsigned int nr, struct nat_entry **ep)
+{
+	return radix_tree_gang_lookup(&nm_i->nat_root, (void **)ep, start, nr);
+}
+
+static void __del_from_nat_cache(struct f2fs_nm_info *nm_i, struct nat_entry *e)
+{
+	radix_tree_delete(&nm_i->nat_root, nat_get_nid(e));
+	nm_i->nat_cnt[TOTAL_NAT]--;
+	nm_i->nat_cnt[RECLAIMABLE_NAT]--;
+	__free_nat_entry(e);
+}
+
+static struct nat_entry_set *__grab_nat_entry_set(struct f2fs_nm_info *nm_i,
+							struct nat_entry *ne)
+{
+	nid_t set = NAT_BLOCK_OFFSET(ne->ni.nid);
+	struct nat_entry_set *head;
+
+	head = radix_tree_lookup(&nm_i->nat_set_root, set);
+	if (!head) {
+		head = f2fs_kmem_cache_alloc(nat_entry_set_slab, GFP_NOFS);
+
+		INIT_LIST_HEAD(&head->entry_list);
+		INIT_LIST_HEAD(&head->set_list);
+		head->set = set;
+		head->entry_cnt = 0;
+		f2fs_radix_tree_insert(&nm_i->nat_set_root, set, head);
+	}
+	return head;
+}
+
+static void __set_nat_cache_dirty(struct f2fs_nm_info *nm_i,
+						struct nat_entry *ne)
+{
+	struct nat_entry_set *head;
+	bool new_ne = nat_get_blkaddr(ne) == NEW_ADDR;
+
+	if (!new_ne)
+		head = __grab_nat_entry_set(nm_i, ne);
+
+	/*
+	 * update entry_cnt in below condition:
+	 * 1. update NEW_ADDR to valid block address;
+	 * 2. update old block address to new one;
+	 */
+	if (!new_ne && (get_nat_flag(ne, IS_PREALLOC) ||
+				!get_nat_flag(ne, IS_DIRTY)))
+		head->entry_cnt++;
+
+	set_nat_flag(ne, IS_PREALLOC, new_ne);
+
+	if (get_nat_flag(ne, IS_DIRTY))
+		goto refresh_list;
+
+	nm_i->nat_cnt[DIRTY_NAT]++;
+	nm_i->nat_cnt[RECLAIMABLE_NAT]--;
+	set_nat_flag(ne, IS_DIRTY, true);
+refresh_list:
+	spin_lock(&nm_i->nat_list_lock);
+	if (new_ne)
+		list_del_init(&ne->list);
+	else
+		list_move_tail(&ne->list, &head->entry_list);
+	spin_unlock(&nm_i->nat_list_lock);
+}
+
+static void __clear_nat_cache_dirty(struct f2fs_nm_info *nm_i,
+		struct nat_entry_set *set, struct nat_entry *ne)
+{
+	spin_lock(&nm_i->nat_list_lock);
+	list_move_tail(&ne->list, &nm_i->nat_entries);
+	spin_unlock(&nm_i->nat_list_lock);
+
+	set_nat_flag(ne, IS_DIRTY, false);
+	set->entry_cnt--;
+	nm_i->nat_cnt[DIRTY_NAT]--;
+	nm_i->nat_cnt[RECLAIMABLE_NAT]++;
+}
+
+static unsigned int __gang_lookup_nat_set(struct f2fs_nm_info *nm_i,
+		nid_t start, unsigned int nr, struct nat_entry_set **ep)
+{
+	return radix_tree_gang_lookup(&nm_i->nat_set_root, (void **)ep,
+							start, nr);
+}
+
+bool f2fs_in_warm_node_list(struct f2fs_sb_info *sbi, struct page *page)
+{
+	return NODE_MAPPING(sbi) == page->mapping &&
+			IS_DNODE(page) && is_cold_node(page);
+}
+
+void f2fs_init_fsync_node_info(struct f2fs_sb_info *sbi)
+{
+	spin_lock_init(&sbi->fsync_node_lock);
+	INIT_LIST_HEAD(&sbi->fsync_node_list);
+	sbi->fsync_seg_id = 0;
+	sbi->fsync_node_num = 0;
+}
+
+static unsigned int f2fs_add_fsync_node_entry(struct f2fs_sb_info *sbi,
+							struct page *page)
+{
+	struct fsync_node_entry *fn;
+	unsigned long flags;
+	unsigned int seq_id;
+
+	fn = f2fs_kmem_cache_alloc(fsync_node_entry_slab, GFP_NOFS);
+
+	get_page(page);
+	fn->page = page;
+	INIT_LIST_HEAD(&fn->list);
+
+	spin_lock_irqsave(&sbi->fsync_node_lock, flags);
+	list_add_tail(&fn->list, &sbi->fsync_node_list);
+	fn->seq_id = sbi->fsync_seg_id++;
+	seq_id = fn->seq_id;
+	sbi->fsync_node_num++;
+	spin_unlock_irqrestore(&sbi->fsync_node_lock, flags);
+
+	return seq_id;
+}
+
+void f2fs_del_fsync_node_entry(struct f2fs_sb_info *sbi, struct page *page)
+{
+	struct fsync_node_entry *fn;
+	unsigned long flags;
+
+	spin_lock_irqsave(&sbi->fsync_node_lock, flags);
+	list_for_each_entry(fn, &sbi->fsync_node_list, list) {
+		if (fn->page == page) {
+			list_del(&fn->list);
+			sbi->fsync_node_num--;
+			spin_unlock_irqrestore(&sbi->fsync_node_lock, flags);
+			kmem_cache_free(fsync_node_entry_slab, fn);
+			put_page(page);
+			return;
+		}
+	}
+	spin_unlock_irqrestore(&sbi->fsync_node_lock, flags);
+	f2fs_bug_on(sbi, 1);
+}
+
+void f2fs_reset_fsync_node_info(struct f2fs_sb_info *sbi)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&sbi->fsync_node_lock, flags);
+	sbi->fsync_seg_id = 0;
+	spin_unlock_irqrestore(&sbi->fsync_node_lock, flags);
+}
+
+int f2fs_need_dentry_mark(struct f2fs_sb_info *sbi, nid_t nid)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct nat_entry *e;
+	bool need = false;
+
+	down_read(&nm_i->nat_tree_lock);
+	e = __lookup_nat_cache(nm_i, nid);
+	if (e) {
+		if (!get_nat_flag(e, IS_CHECKPOINTED) &&
+				!get_nat_flag(e, HAS_FSYNCED_INODE))
+			need = true;
+	}
+	up_read(&nm_i->nat_tree_lock);
+	return need;
+}
+
+bool f2fs_is_checkpointed_node(struct f2fs_sb_info *sbi, nid_t nid)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct nat_entry *e;
+	bool is_cp = true;
+
+	down_read(&nm_i->nat_tree_lock);
+	e = __lookup_nat_cache(nm_i, nid);
+	if (e && !get_nat_flag(e, IS_CHECKPOINTED))
+		is_cp = false;
+	up_read(&nm_i->nat_tree_lock);
+	return is_cp;
+}
+
+bool f2fs_need_inode_block_update(struct f2fs_sb_info *sbi, nid_t ino)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct nat_entry *e;
+	bool need_update = true;
+
+	down_read(&nm_i->nat_tree_lock);
+	e = __lookup_nat_cache(nm_i, ino);
+	if (e && get_nat_flag(e, HAS_LAST_FSYNC) &&
+			(get_nat_flag(e, IS_CHECKPOINTED) ||
+			 get_nat_flag(e, HAS_FSYNCED_INODE)))
+		need_update = false;
+	up_read(&nm_i->nat_tree_lock);
+	return need_update;
+}
+
+/* must be locked by nat_tree_lock */
+static void cache_nat_entry(struct f2fs_sb_info *sbi, nid_t nid,
+						struct f2fs_nat_entry *ne)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct nat_entry *new, *e;
+
+	new = __alloc_nat_entry(nid, false);
+	if (!new)
+		return;
+
+	down_write(&nm_i->nat_tree_lock);
+	e = __lookup_nat_cache(nm_i, nid);
+	if (!e)
+		e = __init_nat_entry(nm_i, new, ne, false);
+	else
+		f2fs_bug_on(sbi, nat_get_ino(e) != le32_to_cpu(ne->ino) ||
+				nat_get_blkaddr(e) !=
+					le32_to_cpu(ne->block_addr) ||
+				nat_get_version(e) != ne->version);
+	up_write(&nm_i->nat_tree_lock);
+	if (e != new)
+		__free_nat_entry(new);
+}
+
+static void set_node_addr(struct f2fs_sb_info *sbi, struct node_info *ni,
+			block_t new_blkaddr, bool fsync_done)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct nat_entry *e;
+	struct nat_entry *new = __alloc_nat_entry(ni->nid, true);
+
+	down_write(&nm_i->nat_tree_lock);
+	e = __lookup_nat_cache(nm_i, ni->nid);
+	if (!e) {
+		e = __init_nat_entry(nm_i, new, NULL, true);
+		copy_node_info(&e->ni, ni);
+		f2fs_bug_on(sbi, ni->blk_addr == NEW_ADDR);
+	} else if (new_blkaddr == NEW_ADDR) {
+		/*
+		 * when nid is reallocated,
+		 * previous nat entry can be remained in nat cache.
+		 * So, reinitialize it with new information.
+		 */
+		copy_node_info(&e->ni, ni);
+		f2fs_bug_on(sbi, ni->blk_addr != NULL_ADDR);
+	}
+	/* let's free early to reduce memory consumption */
+	if (e != new)
+		__free_nat_entry(new);
+
+	/* sanity check */
+	f2fs_bug_on(sbi, nat_get_blkaddr(e) != ni->blk_addr);
+	f2fs_bug_on(sbi, nat_get_blkaddr(e) == NULL_ADDR &&
+			new_blkaddr == NULL_ADDR);
+	f2fs_bug_on(sbi, nat_get_blkaddr(e) == NEW_ADDR &&
+			new_blkaddr == NEW_ADDR);
+	f2fs_bug_on(sbi, __is_valid_data_blkaddr(nat_get_blkaddr(e)) &&
+			new_blkaddr == NEW_ADDR);
+
+	/* increment version no as node is removed */
+	if (nat_get_blkaddr(e) != NEW_ADDR && new_blkaddr == NULL_ADDR) {
+		unsigned char version = nat_get_version(e);
+		nat_set_version(e, inc_node_version(version));
+	}
+
+	/* change address */
+	nat_set_blkaddr(e, new_blkaddr);
+	if (!__is_valid_data_blkaddr(new_blkaddr))
+		set_nat_flag(e, IS_CHECKPOINTED, false);
+	__set_nat_cache_dirty(nm_i, e);
+
+	/* update fsync_mark if its inode nat entry is still alive */
+	if (ni->nid != ni->ino)
+		e = __lookup_nat_cache(nm_i, ni->ino);
+	if (e) {
+		if (fsync_done && ni->nid == ni->ino)
+			set_nat_flag(e, HAS_FSYNCED_INODE, true);
+		set_nat_flag(e, HAS_LAST_FSYNC, fsync_done);
+	}
+	up_write(&nm_i->nat_tree_lock);
+}
+
+int f2fs_try_to_free_nats(struct f2fs_sb_info *sbi, int nr_shrink)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	int nr = nr_shrink;
+
+	if (!down_write_trylock(&nm_i->nat_tree_lock))
+		return 0;
+
+	spin_lock(&nm_i->nat_list_lock);
+	while (nr_shrink) {
+		struct nat_entry *ne;
+
+		if (list_empty(&nm_i->nat_entries))
+			break;
+
+		ne = list_first_entry(&nm_i->nat_entries,
+					struct nat_entry, list);
+		list_del(&ne->list);
+		spin_unlock(&nm_i->nat_list_lock);
+
+		__del_from_nat_cache(nm_i, ne);
+		nr_shrink--;
+
+		spin_lock(&nm_i->nat_list_lock);
+	}
+	spin_unlock(&nm_i->nat_list_lock);
+
+	up_write(&nm_i->nat_tree_lock);
+	return nr - nr_shrink;
+}
+
+int f2fs_get_node_info(struct f2fs_sb_info *sbi, nid_t nid,
+						struct node_info *ni)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
+	struct f2fs_journal *journal = curseg->journal;
+	nid_t start_nid = START_NID(nid);
+	struct f2fs_nat_block *nat_blk;
+	struct page *page = NULL;
+	struct f2fs_nat_entry ne;
+	struct nat_entry *e;
+	pgoff_t index;
+	block_t blkaddr;
+	int i;
+
+	ni->nid = nid;
+
+	/* Check nat cache */
+	down_read(&nm_i->nat_tree_lock);
+	e = __lookup_nat_cache(nm_i, nid);
+	if (e) {
+		ni->ino = nat_get_ino(e);
+		ni->blk_addr = nat_get_blkaddr(e);
+		ni->version = nat_get_version(e);
+		up_read(&nm_i->nat_tree_lock);
+		return 0;
+	}
+
+	memset(&ne, 0, sizeof(struct f2fs_nat_entry));
+
+	/* Check current segment summary */
+	down_read(&curseg->journal_rwsem);
+	i = f2fs_lookup_journal_in_cursum(journal, NAT_JOURNAL, nid, 0);
+	if (i >= 0) {
+		ne = nat_in_journal(journal, i);
+		node_info_from_raw_nat(ni, &ne);
+	}
+	up_read(&curseg->journal_rwsem);
+	if (i >= 0) {
+		up_read(&nm_i->nat_tree_lock);
+		goto cache;
+	}
+
+	/* Fill node_info from nat page */
+	index = current_nat_addr(sbi, nid);
+	up_read(&nm_i->nat_tree_lock);
+
+	page = f2fs_get_meta_page(sbi, index);
+	if (IS_ERR(page))
+		return PTR_ERR(page);
+
+	nat_blk = (struct f2fs_nat_block *)page_address(page);
+	ne = nat_blk->entries[nid - start_nid];
+	node_info_from_raw_nat(ni, &ne);
+	f2fs_put_page(page, 1);
+cache:
+	blkaddr = le32_to_cpu(ne.block_addr);
+	if (__is_valid_data_blkaddr(blkaddr) &&
+		!f2fs_is_valid_blkaddr(sbi, blkaddr, DATA_GENERIC_ENHANCE))
+		return -EFAULT;
+
+	/* cache nat entry */
+	cache_nat_entry(sbi, nid, &ne);
+	return 0;
+}
+
+/*
+ * readahead MAX_RA_NODE number of node pages.
+ */
+static void f2fs_ra_node_pages(struct page *parent, int start, int n)
+{
+	struct f2fs_sb_info *sbi = F2FS_P_SB(parent);
+	struct blk_plug plug;
+	int i, end;
+	nid_t nid;
+
+	blk_start_plug(&plug);
+
+	/* Then, try readahead for siblings of the desired node */
+	end = start + n;
+	end = min(end, NIDS_PER_BLOCK);
+	for (i = start; i < end; i++) {
+		nid = get_nid(parent, i, false);
+		f2fs_ra_node_page(sbi, nid);
+	}
+
+	blk_finish_plug(&plug);
+}
+
+pgoff_t f2fs_get_next_page_offset(struct dnode_of_data *dn, pgoff_t pgofs)
+{
+	const long direct_index = ADDRS_PER_INODE(dn->inode);
+	const long direct_blks = ADDRS_PER_BLOCK(dn->inode);
+	const long indirect_blks = ADDRS_PER_BLOCK(dn->inode) * NIDS_PER_BLOCK;
+	unsigned int skipped_unit = ADDRS_PER_BLOCK(dn->inode);
+	int cur_level = dn->cur_level;
+	int max_level = dn->max_level;
+	pgoff_t base = 0;
+
+	if (!dn->max_level)
+		return pgofs + 1;
+
+	while (max_level-- > cur_level)
+		skipped_unit *= NIDS_PER_BLOCK;
+
+	switch (dn->max_level) {
+	case 3:
+		base += 2 * indirect_blks;
+		fallthrough;
+	case 2:
+		base += 2 * direct_blks;
+		fallthrough;
+	case 1:
+		base += direct_index;
+		break;
+	default:
+		f2fs_bug_on(F2FS_I_SB(dn->inode), 1);
+	}
+
+	return ((pgofs - base) / skipped_unit + 1) * skipped_unit + base;
+}
+
+/*
+ * The maximum depth is four.
+ * Offset[0] will have raw inode offset.
+ */
+static int get_node_path(struct inode *inode, long block,
+				int offset[4], unsigned int noffset[4])
+{
+	const long direct_index = ADDRS_PER_INODE(inode);
+	const long direct_blks = ADDRS_PER_BLOCK(inode);
+	const long dptrs_per_blk = NIDS_PER_BLOCK;
+	const long indirect_blks = ADDRS_PER_BLOCK(inode) * NIDS_PER_BLOCK;
+	const long dindirect_blks = indirect_blks * NIDS_PER_BLOCK;
+	int n = 0;
+	int level = 0;
+
+	noffset[0] = 0;
+
+	if (block < direct_index) {
+		offset[n] = block;
+		goto got;
+	}
+	block -= direct_index;
+	if (block < direct_blks) {
+		offset[n++] = NODE_DIR1_BLOCK;
+		noffset[n] = 1;
+		offset[n] = block;
+		level = 1;
+		goto got;
+	}
+	block -= direct_blks;
+	if (block < direct_blks) {
+		offset[n++] = NODE_DIR2_BLOCK;
+		noffset[n] = 2;
+		offset[n] = block;
+		level = 1;
+		goto got;
+	}
+	block -= direct_blks;
+	if (block < indirect_blks) {
+		offset[n++] = NODE_IND1_BLOCK;
+		noffset[n] = 3;
+		offset[n++] = block / direct_blks;
+		noffset[n] = 4 + offset[n - 1];
+		offset[n] = block % direct_blks;
+		level = 2;
+		goto got;
+	}
+	block -= indirect_blks;
+	if (block < indirect_blks) {
+		offset[n++] = NODE_IND2_BLOCK;
+		noffset[n] = 4 + dptrs_per_blk;
+		offset[n++] = block / direct_blks;
+		noffset[n] = 5 + dptrs_per_blk + offset[n - 1];
+		offset[n] = block % direct_blks;
+		level = 2;
+		goto got;
+	}
+	block -= indirect_blks;
+	if (block < dindirect_blks) {
+		offset[n++] = NODE_DIND_BLOCK;
+		noffset[n] = 5 + (dptrs_per_blk * 2);
+		offset[n++] = block / indirect_blks;
+		noffset[n] = 6 + (dptrs_per_blk * 2) +
+			      offset[n - 1] * (dptrs_per_blk + 1);
+		offset[n++] = (block / direct_blks) % dptrs_per_blk;
+		noffset[n] = 7 + (dptrs_per_blk * 2) +
+			      offset[n - 2] * (dptrs_per_blk + 1) +
+			      offset[n - 1];
+		offset[n] = block % direct_blks;
+		level = 3;
+		goto got;
+	} else {
+		return -E2BIG;
+	}
+got:
+	return level;
+}
+
+/*
+ * Caller should call f2fs_put_dnode(dn).
+ * Also, it should grab and release a rwsem by calling f2fs_lock_op() and
+ * f2fs_unlock_op() only if mode is set with ALLOC_NODE.
+ */
+int f2fs_get_dnode_of_data(struct dnode_of_data *dn, pgoff_t index, int mode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
+	struct page *npage[4];
+	struct page *parent = NULL;
+	int offset[4];
+	unsigned int noffset[4];
+	nid_t nids[4];
+	int level, i = 0;
+	int err = 0;
+
+	level = get_node_path(dn->inode, index, offset, noffset);
+	if (level < 0)
+		return level;
+
+	nids[0] = dn->inode->i_ino;
+	npage[0] = dn->inode_page;
+
+	if (!npage[0]) {
+		npage[0] = f2fs_get_node_page(sbi, nids[0]);
+		if (IS_ERR(npage[0]))
+			return PTR_ERR(npage[0]);
+	}
+
+	/* if inline_data is set, should not report any block indices */
+	if (f2fs_has_inline_data(dn->inode) && index) {
+		err = -ENOENT;
+		f2fs_put_page(npage[0], 1);
+		goto release_out;
+	}
+
+	parent = npage[0];
+	if (level != 0)
+		nids[1] = get_nid(parent, offset[0], true);
+	dn->inode_page = npage[0];
+	dn->inode_page_locked = true;
+
+	/* get indirect or direct nodes */
+	for (i = 1; i <= level; i++) {
+		bool done = false;
+
+		if (!nids[i] && mode == ALLOC_NODE) {
+			/* alloc new node */
+			if (!f2fs_alloc_nid(sbi, &(nids[i]))) {
+				err = -ENOSPC;
+				goto release_pages;
+			}
+
+			dn->nid = nids[i];
+			npage[i] = f2fs_new_node_page(dn, noffset[i]);
+			if (IS_ERR(npage[i])) {
+				f2fs_alloc_nid_failed(sbi, nids[i]);
+				err = PTR_ERR(npage[i]);
+				goto release_pages;
+			}
+
+			set_nid(parent, offset[i - 1], nids[i], i == 1);
+			f2fs_alloc_nid_done(sbi, nids[i]);
+			done = true;
+		} else if (mode == LOOKUP_NODE_RA && i == level && level > 1) {
+			npage[i] = f2fs_get_node_page_ra(parent, offset[i - 1]);
+			if (IS_ERR(npage[i])) {
+				err = PTR_ERR(npage[i]);
+				goto release_pages;
+			}
+			done = true;
+		}
+		if (i == 1) {
+			dn->inode_page_locked = false;
+			unlock_page(parent);
+		} else {
+			f2fs_put_page(parent, 1);
+		}
+
+		if (!done) {
+			npage[i] = f2fs_get_node_page(sbi, nids[i]);
+			if (IS_ERR(npage[i])) {
+				err = PTR_ERR(npage[i]);
+				f2fs_put_page(npage[0], 0);
+				goto release_out;
+			}
+		}
+		if (i < level) {
+			parent = npage[i];
+			nids[i + 1] = get_nid(parent, offset[i], false);
+		}
+	}
+	dn->nid = nids[level];
+	dn->ofs_in_node = offset[level];
+	dn->node_page = npage[level];
+	dn->data_blkaddr = f2fs_data_blkaddr(dn);
+	return 0;
+
+release_pages:
+	f2fs_put_page(parent, 1);
+	if (i > 1)
+		f2fs_put_page(npage[0], 0);
+release_out:
+	dn->inode_page = NULL;
+	dn->node_page = NULL;
+	if (err == -ENOENT) {
+		dn->cur_level = i;
+		dn->max_level = level;
+		dn->ofs_in_node = offset[level];
+	}
+	return err;
+}
+
+static int truncate_node(struct dnode_of_data *dn)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
+	struct node_info ni;
+	int err;
+	pgoff_t index;
+
+	err = f2fs_get_node_info(sbi, dn->nid, &ni);
+	if (err)
+		return err;
+
+	/* Deallocate node address */
+	f2fs_invalidate_blocks(sbi, ni.blk_addr);
+	dec_valid_node_count(sbi, dn->inode, dn->nid == dn->inode->i_ino);
+	set_node_addr(sbi, &ni, NULL_ADDR, false);
+
+	if (dn->nid == dn->inode->i_ino) {
+		f2fs_remove_orphan_inode(sbi, dn->nid);
+		dec_valid_inode_count(sbi);
+		f2fs_inode_synced(dn->inode);
+	}
+
+	clear_node_page_dirty(dn->node_page);
+	set_sbi_flag(sbi, SBI_IS_DIRTY);
+
+	index = dn->node_page->index;
+	f2fs_put_page(dn->node_page, 1);
+
+	invalidate_mapping_pages(NODE_MAPPING(sbi),
+			index, index);
+
+	dn->node_page = NULL;
+	trace_f2fs_truncate_node(dn->inode, dn->nid, ni.blk_addr);
+
+	return 0;
+}
+
+static int truncate_dnode(struct dnode_of_data *dn)
+{
+	struct page *page;
+	int err;
+
+	if (dn->nid == 0)
+		return 1;
+
+	/* get direct node */
+	page = f2fs_get_node_page(F2FS_I_SB(dn->inode), dn->nid);
+	if (PTR_ERR(page) == -ENOENT)
+		return 1;
+	else if (IS_ERR(page))
+		return PTR_ERR(page);
+
+	/* Make dnode_of_data for parameter */
+	dn->node_page = page;
+	dn->ofs_in_node = 0;
+	f2fs_truncate_data_blocks(dn);
+	err = truncate_node(dn);
+	if (err) {
+		f2fs_put_page(page, 1);
+		return err;
+	}
+
+	return 1;
+}
+
+static int truncate_nodes(struct dnode_of_data *dn, unsigned int nofs,
+						int ofs, int depth)
+{
+	struct dnode_of_data rdn = *dn;
+	struct page *page;
+	struct f2fs_node *rn;
+	nid_t child_nid;
+	unsigned int child_nofs;
+	int freed = 0;
+	int i, ret;
+
+	if (dn->nid == 0)
+		return NIDS_PER_BLOCK + 1;
+
+	trace_f2fs_truncate_nodes_enter(dn->inode, dn->nid, dn->data_blkaddr);
+
+	page = f2fs_get_node_page(F2FS_I_SB(dn->inode), dn->nid);
+	if (IS_ERR(page)) {
+		trace_f2fs_truncate_nodes_exit(dn->inode, PTR_ERR(page));
+		return PTR_ERR(page);
+	}
+
+	f2fs_ra_node_pages(page, ofs, NIDS_PER_BLOCK);
+
+	rn = F2FS_NODE(page);
+	if (depth < 3) {
+		for (i = ofs; i < NIDS_PER_BLOCK; i++, freed++) {
+			child_nid = le32_to_cpu(rn->in.nid[i]);
+			if (child_nid == 0)
+				continue;
+			rdn.nid = child_nid;
+			ret = truncate_dnode(&rdn);
+			if (ret < 0)
+				goto out_err;
+			if (set_nid(page, i, 0, false))
+				dn->node_changed = true;
+		}
+	} else {
+		child_nofs = nofs + ofs * (NIDS_PER_BLOCK + 1) + 1;
+		for (i = ofs; i < NIDS_PER_BLOCK; i++) {
+			child_nid = le32_to_cpu(rn->in.nid[i]);
+			if (child_nid == 0) {
+				child_nofs += NIDS_PER_BLOCK + 1;
+				continue;
+			}
+			rdn.nid = child_nid;
+			ret = truncate_nodes(&rdn, child_nofs, 0, depth - 1);
+			if (ret == (NIDS_PER_BLOCK + 1)) {
+				if (set_nid(page, i, 0, false))
+					dn->node_changed = true;
+				child_nofs += ret;
+			} else if (ret < 0 && ret != -ENOENT) {
+				goto out_err;
+			}
+		}
+		freed = child_nofs;
+	}
+
+	if (!ofs) {
+		/* remove current indirect node */
+		dn->node_page = page;
+		ret = truncate_node(dn);
+		if (ret)
+			goto out_err;
+		freed++;
+	} else {
+		f2fs_put_page(page, 1);
+	}
+	trace_f2fs_truncate_nodes_exit(dn->inode, freed);
+	return freed;
+
+out_err:
+	f2fs_put_page(page, 1);
+	trace_f2fs_truncate_nodes_exit(dn->inode, ret);
+	return ret;
+}
+
+static int truncate_partial_nodes(struct dnode_of_data *dn,
+			struct f2fs_inode *ri, int *offset, int depth)
+{
+	struct page *pages[2];
+	nid_t nid[3];
+	nid_t child_nid;
+	int err = 0;
+	int i;
+	int idx = depth - 2;
+
+	nid[0] = le32_to_cpu(ri->i_nid[offset[0] - NODE_DIR1_BLOCK]);
+	if (!nid[0])
+		return 0;
+
+	/* get indirect nodes in the path */
+	for (i = 0; i < idx + 1; i++) {
+		/* reference count'll be increased */
+		pages[i] = f2fs_get_node_page(F2FS_I_SB(dn->inode), nid[i]);
+		if (IS_ERR(pages[i])) {
+			err = PTR_ERR(pages[i]);
+			idx = i - 1;
+			goto fail;
+		}
+		nid[i + 1] = get_nid(pages[i], offset[i + 1], false);
+	}
+
+	f2fs_ra_node_pages(pages[idx], offset[idx + 1], NIDS_PER_BLOCK);
+
+	/* free direct nodes linked to a partial indirect node */
+	for (i = offset[idx + 1]; i < NIDS_PER_BLOCK; i++) {
+		child_nid = get_nid(pages[idx], i, false);
+		if (!child_nid)
+			continue;
+		dn->nid = child_nid;
+		err = truncate_dnode(dn);
+		if (err < 0)
+			goto fail;
+		if (set_nid(pages[idx], i, 0, false))
+			dn->node_changed = true;
+	}
+
+	if (offset[idx + 1] == 0) {
+		dn->node_page = pages[idx];
+		dn->nid = nid[idx];
+		err = truncate_node(dn);
+		if (err)
+			goto fail;
+	} else {
+		f2fs_put_page(pages[idx], 1);
+	}
+	offset[idx]++;
+	offset[idx + 1] = 0;
+	idx--;
+fail:
+	for (i = idx; i >= 0; i--)
+		f2fs_put_page(pages[i], 1);
+
+	trace_f2fs_truncate_partial_nodes(dn->inode, nid, depth, err);
+
+	return err;
+}
+
+/*
+ * All the block addresses of data and nodes should be nullified.
+ */
+int f2fs_truncate_inode_blocks(struct inode *inode, pgoff_t from)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	int err = 0, cont = 1;
+	int level, offset[4], noffset[4];
+	unsigned int nofs = 0;
+	struct f2fs_inode *ri;
+	struct dnode_of_data dn;
+	struct page *page;
+
+	trace_f2fs_truncate_inode_blocks_enter(inode, from);
+
+	level = get_node_path(inode, from, offset, noffset);
+	if (level < 0) {
+		trace_f2fs_truncate_inode_blocks_exit(inode, level);
+		return level;
+	}
+
+	page = f2fs_get_node_page(sbi, inode->i_ino);
+	if (IS_ERR(page)) {
+		trace_f2fs_truncate_inode_blocks_exit(inode, PTR_ERR(page));
+		return PTR_ERR(page);
+	}
+
+	set_new_dnode(&dn, inode, page, NULL, 0);
+	unlock_page(page);
+
+	ri = F2FS_INODE(page);
+	switch (level) {
+	case 0:
+	case 1:
+		nofs = noffset[1];
+		break;
+	case 2:
+		nofs = noffset[1];
+		if (!offset[level - 1])
+			goto skip_partial;
+		err = truncate_partial_nodes(&dn, ri, offset, level);
+		if (err < 0 && err != -ENOENT)
+			goto fail;
+		nofs += 1 + NIDS_PER_BLOCK;
+		break;
+	case 3:
+		nofs = 5 + 2 * NIDS_PER_BLOCK;
+		if (!offset[level - 1])
+			goto skip_partial;
+		err = truncate_partial_nodes(&dn, ri, offset, level);
+		if (err < 0 && err != -ENOENT)
+			goto fail;
+		break;
+	default:
+		BUG();
+	}
+
+skip_partial:
+	while (cont) {
+		dn.nid = le32_to_cpu(ri->i_nid[offset[0] - NODE_DIR1_BLOCK]);
+		switch (offset[0]) {
+		case NODE_DIR1_BLOCK:
+		case NODE_DIR2_BLOCK:
+			err = truncate_dnode(&dn);
+			break;
+
+		case NODE_IND1_BLOCK:
+		case NODE_IND2_BLOCK:
+			err = truncate_nodes(&dn, nofs, offset[1], 2);
+			break;
+
+		case NODE_DIND_BLOCK:
+			err = truncate_nodes(&dn, nofs, offset[1], 3);
+			cont = 0;
+			break;
+
+		default:
+			BUG();
+		}
+		if (err < 0 && err != -ENOENT)
+			goto fail;
+		if (offset[1] == 0 &&
+				ri->i_nid[offset[0] - NODE_DIR1_BLOCK]) {
+			lock_page(page);
+			BUG_ON(page->mapping != NODE_MAPPING(sbi));
+			f2fs_wait_on_page_writeback(page, NODE, true, true);
+			ri->i_nid[offset[0] - NODE_DIR1_BLOCK] = 0;
+			set_page_dirty(page);
+			unlock_page(page);
+		}
+		offset[1] = 0;
+		offset[0]++;
+		nofs += err;
+	}
+fail:
+	f2fs_put_page(page, 0);
+	trace_f2fs_truncate_inode_blocks_exit(inode, err);
+	return err > 0 ? 0 : err;
+}
+
+/* caller must lock inode page */
+int f2fs_truncate_xattr_node(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	nid_t nid = F2FS_I(inode)->i_xattr_nid;
+	struct dnode_of_data dn;
+	struct page *npage;
+	int err;
+
+	if (!nid)
+		return 0;
+
+	npage = f2fs_get_node_page(sbi, nid);
+	if (IS_ERR(npage))
+		return PTR_ERR(npage);
+
+	set_new_dnode(&dn, inode, NULL, npage, nid);
+	err = truncate_node(&dn);
+	if (err) {
+		f2fs_put_page(npage, 1);
+		return err;
+	}
+
+	f2fs_i_xnid_write(inode, 0);
+
+	return 0;
+}
+
+/*
+ * Caller should grab and release a rwsem by calling f2fs_lock_op() and
+ * f2fs_unlock_op().
+ */
+int f2fs_remove_inode_page(struct inode *inode)
+{
+	struct dnode_of_data dn;
+	int err;
+
+	set_new_dnode(&dn, inode, NULL, NULL, inode->i_ino);
+	err = f2fs_get_dnode_of_data(&dn, 0, LOOKUP_NODE);
+	if (err)
+		return err;
+
+	err = f2fs_truncate_xattr_node(inode);
+	if (err) {
+		f2fs_put_dnode(&dn);
+		return err;
+	}
+
+	/* remove potential inline_data blocks */
+	if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
+				S_ISLNK(inode->i_mode))
+		f2fs_truncate_data_blocks_range(&dn, 1);
+
+	/* 0 is possible, after f2fs_new_inode() has failed */
+	if (unlikely(f2fs_cp_error(F2FS_I_SB(inode)))) {
+		f2fs_put_dnode(&dn);
+		return -EIO;
+	}
+
+	if (unlikely(inode->i_blocks != 0 && inode->i_blocks != 8)) {
+		f2fs_warn(F2FS_I_SB(inode),
+			"f2fs_remove_inode_page: inconsistent i_blocks, ino:%lu, iblocks:%llu",
+			inode->i_ino, (unsigned long long)inode->i_blocks);
+		set_sbi_flag(F2FS_I_SB(inode), SBI_NEED_FSCK);
+	}
+
+	/* will put inode & node pages */
+	err = truncate_node(&dn);
+	if (err) {
+		f2fs_put_dnode(&dn);
+		return err;
+	}
+	return 0;
+}
+
+struct page *f2fs_new_inode_page(struct inode *inode)
+{
+	struct dnode_of_data dn;
+
+	/* allocate inode page for new inode */
+	set_new_dnode(&dn, inode, NULL, NULL, inode->i_ino);
+
+	/* caller should f2fs_put_page(page, 1); */
+	return f2fs_new_node_page(&dn, 0);
+}
+
+struct page *f2fs_new_node_page(struct dnode_of_data *dn, unsigned int ofs)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
+	struct node_info new_ni;
+	struct page *page;
+	int err;
+
+	if (unlikely(is_inode_flag_set(dn->inode, FI_NO_ALLOC)))
+		return ERR_PTR(-EPERM);
+
+	page = f2fs_grab_cache_page(NODE_MAPPING(sbi), dn->nid, false);
+	if (!page)
+		return ERR_PTR(-ENOMEM);
+
+	if (unlikely((err = inc_valid_node_count(sbi, dn->inode, !ofs))))
+		goto fail;
+
+#ifdef CONFIG_F2FS_CHECK_FS
+	err = f2fs_get_node_info(sbi, dn->nid, &new_ni);
+	if (err) {
+		dec_valid_node_count(sbi, dn->inode, !ofs);
+		goto fail;
+	}
+	if (unlikely(new_ni.blk_addr != NULL_ADDR)) {
+		err = -EFSCORRUPTED;
+		set_sbi_flag(sbi, SBI_NEED_FSCK);
+		goto fail;
+	}
+#endif
+	new_ni.nid = dn->nid;
+	new_ni.ino = dn->inode->i_ino;
+	new_ni.blk_addr = NULL_ADDR;
+	new_ni.flag = 0;
+	new_ni.version = 0;
+	set_node_addr(sbi, &new_ni, NEW_ADDR, false);
+
+	f2fs_wait_on_page_writeback(page, NODE, true, true);
+	fill_node_footer(page, dn->nid, dn->inode->i_ino, ofs, true);
+	set_cold_node(page, S_ISDIR(dn->inode->i_mode));
+	if (!PageUptodate(page))
+		SetPageUptodate(page);
+	if (set_page_dirty(page))
+		dn->node_changed = true;
+
+	if (f2fs_has_xattr_block(ofs))
+		f2fs_i_xnid_write(dn->inode, dn->nid);
+
+	if (ofs == 0)
+		inc_valid_inode_count(sbi);
+	return page;
+
+fail:
+	clear_node_page_dirty(page);
+	f2fs_put_page(page, 1);
+	return ERR_PTR(err);
+}
+
+/*
+ * Caller should do after getting the following values.
+ * 0: f2fs_put_page(page, 0)
+ * LOCKED_PAGE or error: f2fs_put_page(page, 1)
+ */
+static int read_node_page(struct page *page, int op_flags)
+{
+	struct f2fs_sb_info *sbi = F2FS_P_SB(page);
+	struct node_info ni;
+	struct f2fs_io_info fio = {
+		.sbi = sbi,
+		.type = NODE,
+		.op = REQ_OP_READ,
+		.op_flags = op_flags,
+		.page = page,
+		.encrypted_page = NULL,
+	};
+	int err;
+
+	if (PageUptodate(page)) {
+		if (!f2fs_inode_chksum_verify(sbi, page)) {
+			ClearPageUptodate(page);
+			return -EFSBADCRC;
+		}
+		return LOCKED_PAGE;
+	}
+
+	err = f2fs_get_node_info(sbi, page->index, &ni);
+	if (err)
+		return err;
+
+	if (unlikely(ni.blk_addr == NULL_ADDR) ||
+			is_sbi_flag_set(sbi, SBI_IS_SHUTDOWN)) {
+		ClearPageUptodate(page);
+		return -ENOENT;
+	}
+
+	fio.new_blkaddr = fio.old_blkaddr = ni.blk_addr;
+
+	err = f2fs_submit_page_bio(&fio);
+
+	if (!err)
+		f2fs_update_iostat(sbi, FS_NODE_READ_IO, F2FS_BLKSIZE);
+
+	return err;
+}
+
+/*
+ * Readahead a node page
+ */
+void f2fs_ra_node_page(struct f2fs_sb_info *sbi, nid_t nid)
+{
+	struct page *apage;
+	int err;
+
+	if (!nid)
+		return;
+	if (f2fs_check_nid_range(sbi, nid))
+		return;
+
+	apage = xa_load(&NODE_MAPPING(sbi)->i_pages, nid);
+	if (apage)
+		return;
+
+	apage = f2fs_grab_cache_page(NODE_MAPPING(sbi), nid, false);
+	if (!apage)
+		return;
+
+	err = read_node_page(apage, REQ_RAHEAD);
+	f2fs_put_page(apage, err ? 1 : 0);
+}
+
+static struct page *__get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid,
+					struct page *parent, int start)
+{
+	struct page *page;
+	int err;
+
+	if (!nid)
+		return ERR_PTR(-ENOENT);
+	if (f2fs_check_nid_range(sbi, nid))
+		return ERR_PTR(-EINVAL);
+repeat:
+	page = f2fs_grab_cache_page(NODE_MAPPING(sbi), nid, false);
+	if (!page)
+		return ERR_PTR(-ENOMEM);
+
+	err = read_node_page(page, 0);
+	if (err < 0) {
+		f2fs_put_page(page, 1);
+		return ERR_PTR(err);
+	} else if (err == LOCKED_PAGE) {
+		err = 0;
+		goto page_hit;
+	}
+
+	if (parent)
+		f2fs_ra_node_pages(parent, start + 1, MAX_RA_NODE);
+
+	lock_page(page);
+
+	if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
+		f2fs_put_page(page, 1);
+		goto repeat;
+	}
+
+	if (unlikely(!PageUptodate(page))) {
+		err = -EIO;
+		goto out_err;
+	}
+
+	if (!f2fs_inode_chksum_verify(sbi, page)) {
+		err = -EFSBADCRC;
+		goto out_err;
+	}
+page_hit:
+	if(unlikely(nid != nid_of_node(page))) {
+		f2fs_warn(sbi, "inconsistent node block, nid:%lu, node_footer[nid:%u,ino:%u,ofs:%u,cpver:%llu,blkaddr:%u]",
+			  nid, nid_of_node(page), ino_of_node(page),
+			  ofs_of_node(page), cpver_of_node(page),
+			  next_blkaddr_of_node(page));
+		set_sbi_flag(sbi, SBI_NEED_FSCK);
+		err = -EINVAL;
+out_err:
+		ClearPageUptodate(page);
+		f2fs_put_page(page, 1);
+		return ERR_PTR(err);
+	}
+	return page;
+}
+
+struct page *f2fs_get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid)
+{
+	return __get_node_page(sbi, nid, NULL, 0);
+}
+
+struct page *f2fs_get_node_page_ra(struct page *parent, int start)
+{
+	struct f2fs_sb_info *sbi = F2FS_P_SB(parent);
+	nid_t nid = get_nid(parent, start, false);
+
+	return __get_node_page(sbi, nid, parent, start);
+}
+
+static void flush_inline_data(struct f2fs_sb_info *sbi, nid_t ino)
+{
+	struct inode *inode;
+	struct page *page;
+	int ret;
+
+	/* should flush inline_data before evict_inode */
+	inode = ilookup(sbi->sb, ino);
+	if (!inode)
+		return;
+
+	page = f2fs_pagecache_get_page(inode->i_mapping, 0,
+					FGP_LOCK|FGP_NOWAIT, 0);
+	if (!page)
+		goto iput_out;
+
+	if (!PageUptodate(page))
+		goto page_out;
+
+	if (!PageDirty(page))
+		goto page_out;
+
+	if (!clear_page_dirty_for_io(page))
+		goto page_out;
+
+	ret = f2fs_write_inline_data(inode, page);
+	inode_dec_dirty_pages(inode);
+	f2fs_remove_dirty_inode(inode);
+	if (ret)
+		set_page_dirty(page);
+page_out:
+	f2fs_put_page(page, 1);
+iput_out:
+	iput(inode);
+}
+
+static struct page *last_fsync_dnode(struct f2fs_sb_info *sbi, nid_t ino)
+{
+	pgoff_t index;
+	struct pagevec pvec;
+	struct page *last_page = NULL;
+	int nr_pages;
+
+	pagevec_init(&pvec);
+	index = 0;
+
+	while ((nr_pages = pagevec_lookup_tag(&pvec, NODE_MAPPING(sbi), &index,
+				PAGECACHE_TAG_DIRTY))) {
+		int i;
+
+		for (i = 0; i < nr_pages; i++) {
+			struct page *page = pvec.pages[i];
+
+			if (unlikely(f2fs_cp_error(sbi))) {
+				f2fs_put_page(last_page, 0);
+				pagevec_release(&pvec);
+				return ERR_PTR(-EIO);
+			}
+
+			if (!IS_DNODE(page) || !is_cold_node(page))
+				continue;
+			if (ino_of_node(page) != ino)
+				continue;
+
+			lock_page(page);
+
+			if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
+continue_unlock:
+				unlock_page(page);
+				continue;
+			}
+			if (ino_of_node(page) != ino)
+				goto continue_unlock;
+
+			if (!PageDirty(page)) {
+				/* someone wrote it for us */
+				goto continue_unlock;
+			}
+
+			if (last_page)
+				f2fs_put_page(last_page, 0);
+
+			get_page(page);
+			last_page = page;
+			unlock_page(page);
+		}
+		pagevec_release(&pvec);
+		cond_resched();
+	}
+	return last_page;
+}
+
+static int __write_node_page(struct page *page, bool atomic, bool *submitted,
+				struct writeback_control *wbc, bool do_balance,
+				enum iostat_type io_type, unsigned int *seq_id)
+{
+	struct f2fs_sb_info *sbi = F2FS_P_SB(page);
+	nid_t nid;
+	struct node_info ni;
+	struct f2fs_io_info fio = {
+		.sbi = sbi,
+		.ino = ino_of_node(page),
+		.type = NODE,
+		.op = REQ_OP_WRITE,
+		.op_flags = wbc_to_write_flags(wbc),
+		.page = page,
+		.encrypted_page = NULL,
+		.submitted = false,
+		.io_type = io_type,
+		.io_wbc = wbc,
+	};
+	unsigned int seq;
+
+	trace_f2fs_writepage(page, NODE);
+
+	if (unlikely(f2fs_cp_error(sbi))) {
+		if (is_sbi_flag_set(sbi, SBI_IS_CLOSE)) {
+			ClearPageUptodate(page);
+			dec_page_count(sbi, F2FS_DIRTY_NODES);
+			unlock_page(page);
+			return 0;
+		}
+		goto redirty_out;
+	}
+
+	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
+		goto redirty_out;
+
+	if (!is_sbi_flag_set(sbi, SBI_CP_DISABLED) &&
+			wbc->sync_mode == WB_SYNC_NONE &&
+			IS_DNODE(page) && is_cold_node(page))
+		goto redirty_out;
+
+	/* get old block addr of this node page */
+	nid = nid_of_node(page);
+	f2fs_bug_on(sbi, page->index != nid);
+
+	if (f2fs_get_node_info(sbi, nid, &ni))
+		goto redirty_out;
+
+	if (wbc->for_reclaim) {
+		if (!down_read_trylock(&sbi->node_write))
+			goto redirty_out;
+	} else {
+		down_read(&sbi->node_write);
+	}
+
+	/* This page is already truncated */
+	if (unlikely(ni.blk_addr == NULL_ADDR)) {
+		ClearPageUptodate(page);
+		dec_page_count(sbi, F2FS_DIRTY_NODES);
+		up_read(&sbi->node_write);
+		unlock_page(page);
+		return 0;
+	}
+
+	if (__is_valid_data_blkaddr(ni.blk_addr) &&
+		!f2fs_is_valid_blkaddr(sbi, ni.blk_addr,
+					DATA_GENERIC_ENHANCE)) {
+		up_read(&sbi->node_write);
+		goto redirty_out;
+	}
+
+	if (atomic && !test_opt(sbi, NOBARRIER))
+		fio.op_flags |= REQ_PREFLUSH | REQ_FUA;
+
+	/* should add to global list before clearing PAGECACHE status */
+	if (f2fs_in_warm_node_list(sbi, page)) {
+		seq = f2fs_add_fsync_node_entry(sbi, page);
+		if (seq_id)
+			*seq_id = seq;
+	}
+
+	set_page_writeback(page);
+	ClearPageError(page);
+
+	fio.old_blkaddr = ni.blk_addr;
+	f2fs_do_write_node_page(nid, &fio);
+	set_node_addr(sbi, &ni, fio.new_blkaddr, is_fsync_dnode(page));
+	dec_page_count(sbi, F2FS_DIRTY_NODES);
+	up_read(&sbi->node_write);
+
+	if (wbc->for_reclaim) {
+		f2fs_submit_merged_write_cond(sbi, NULL, page, 0, NODE);
+		submitted = NULL;
+	}
+
+	unlock_page(page);
+
+	if (unlikely(f2fs_cp_error(sbi))) {
+		f2fs_submit_merged_write(sbi, NODE);
+		submitted = NULL;
+	}
+	if (submitted)
+		*submitted = fio.submitted;
+
+	if (do_balance)
+		f2fs_balance_fs(sbi, false);
+	return 0;
+
+redirty_out:
+	redirty_page_for_writepage(wbc, page);
+	return AOP_WRITEPAGE_ACTIVATE;
+}
+
+int f2fs_move_node_page(struct page *node_page, int gc_type)
+{
+	int err = 0;
+
+	if (gc_type == FG_GC) {
+		struct writeback_control wbc = {
+			.sync_mode = WB_SYNC_ALL,
+			.nr_to_write = 1,
+			.for_reclaim = 0,
+		};
+
+		f2fs_wait_on_page_writeback(node_page, NODE, true, true);
+
+		set_page_dirty(node_page);
+
+		if (!clear_page_dirty_for_io(node_page)) {
+			err = -EAGAIN;
+			goto out_page;
+		}
+
+		if (__write_node_page(node_page, false, NULL,
+					&wbc, false, FS_GC_NODE_IO, NULL)) {
+			err = -EAGAIN;
+			unlock_page(node_page);
+		}
+		goto release_page;
+	} else {
+		/* set page dirty and write it */
+		if (!PageWriteback(node_page))
+			set_page_dirty(node_page);
+	}
+out_page:
+	unlock_page(node_page);
+release_page:
+	f2fs_put_page(node_page, 0);
+	return err;
+}
+
+static int f2fs_write_node_page(struct page *page,
+				struct writeback_control *wbc)
+{
+	return __write_node_page(page, false, NULL, wbc, false,
+						FS_NODE_IO, NULL);
+}
+
+int f2fs_fsync_node_pages(struct f2fs_sb_info *sbi, struct inode *inode,
+			struct writeback_control *wbc, bool atomic,
+			unsigned int *seq_id)
+{
+	pgoff_t index;
+	struct pagevec pvec;
+	int ret = 0;
+	struct page *last_page = NULL;
+	bool marked = false;
+	nid_t ino = inode->i_ino;
+	int nr_pages;
+	int nwritten = 0;
+
+	if (atomic) {
+		last_page = last_fsync_dnode(sbi, ino);
+		if (IS_ERR_OR_NULL(last_page))
+			return PTR_ERR_OR_ZERO(last_page);
+	}
+retry:
+	pagevec_init(&pvec);
+	index = 0;
+
+	while ((nr_pages = pagevec_lookup_tag(&pvec, NODE_MAPPING(sbi), &index,
+				PAGECACHE_TAG_DIRTY))) {
+		int i;
+
+		for (i = 0; i < nr_pages; i++) {
+			struct page *page = pvec.pages[i];
+			bool submitted = false;
+
+			if (unlikely(f2fs_cp_error(sbi))) {
+				f2fs_put_page(last_page, 0);
+				pagevec_release(&pvec);
+				ret = -EIO;
+				goto out;
+			}
+
+			if (!IS_DNODE(page) || !is_cold_node(page))
+				continue;
+			if (ino_of_node(page) != ino)
+				continue;
+
+			lock_page(page);
+
+			if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
+continue_unlock:
+				unlock_page(page);
+				continue;
+			}
+			if (ino_of_node(page) != ino)
+				goto continue_unlock;
+
+			if (!PageDirty(page) && page != last_page) {
+				/* someone wrote it for us */
+				goto continue_unlock;
+			}
+
+			f2fs_wait_on_page_writeback(page, NODE, true, true);
+
+			set_fsync_mark(page, 0);
+			set_dentry_mark(page, 0);
+
+			if (!atomic || page == last_page) {
+				set_fsync_mark(page, 1);
+				if (IS_INODE(page)) {
+					if (is_inode_flag_set(inode,
+								FI_DIRTY_INODE))
+						f2fs_update_inode(inode, page);
+					set_dentry_mark(page,
+						f2fs_need_dentry_mark(sbi, ino));
+				}
+				/* may be written by other thread */
+				if (!PageDirty(page))
+					set_page_dirty(page);
+			}
+
+			if (!clear_page_dirty_for_io(page))
+				goto continue_unlock;
+
+			ret = __write_node_page(page, atomic &&
+						page == last_page,
+						&submitted, wbc, true,
+						FS_NODE_IO, seq_id);
+			if (ret) {
+				unlock_page(page);
+				f2fs_put_page(last_page, 0);
+				break;
+			} else if (submitted) {
+				nwritten++;
+			}
+
+			if (page == last_page) {
+				f2fs_put_page(page, 0);
+				marked = true;
+				break;
+			}
+		}
+		pagevec_release(&pvec);
+		cond_resched();
+
+		if (ret || marked)
+			break;
+	}
+	if (!ret && atomic && !marked) {
+		f2fs_debug(sbi, "Retry to write fsync mark: ino=%u, idx=%lx",
+			   ino, last_page->index);
+		lock_page(last_page);
+		f2fs_wait_on_page_writeback(last_page, NODE, true, true);
+		set_page_dirty(last_page);
+		unlock_page(last_page);
+		goto retry;
+	}
+out:
+	if (nwritten)
+		f2fs_submit_merged_write_cond(sbi, NULL, NULL, ino, NODE);
+	return ret ? -EIO: 0;
+}
+
+static int f2fs_match_ino(struct inode *inode, unsigned long ino, void *data)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	bool clean;
+
+	if (inode->i_ino != ino)
+		return 0;
+
+	if (!is_inode_flag_set(inode, FI_DIRTY_INODE))
+		return 0;
+
+	spin_lock(&sbi->inode_lock[DIRTY_META]);
+	clean = list_empty(&F2FS_I(inode)->gdirty_list);
+	spin_unlock(&sbi->inode_lock[DIRTY_META]);
+
+	if (clean)
+		return 0;
+
+	inode = igrab(inode);
+	if (!inode)
+		return 0;
+	return 1;
+}
+
+static bool flush_dirty_inode(struct page *page)
+{
+	struct f2fs_sb_info *sbi = F2FS_P_SB(page);
+	struct inode *inode;
+	nid_t ino = ino_of_node(page);
+
+	inode = find_inode_nowait(sbi->sb, ino, f2fs_match_ino, NULL);
+	if (!inode)
+		return false;
+
+	f2fs_update_inode(inode, page);
+	unlock_page(page);
+
+	iput(inode);
+	return true;
+}
+
+void f2fs_flush_inline_data(struct f2fs_sb_info *sbi)
+{
+	pgoff_t index = 0;
+	struct pagevec pvec;
+	int nr_pages;
+
+	pagevec_init(&pvec);
+
+	while ((nr_pages = pagevec_lookup_tag(&pvec,
+			NODE_MAPPING(sbi), &index, PAGECACHE_TAG_DIRTY))) {
+		int i;
+
+		for (i = 0; i < nr_pages; i++) {
+			struct page *page = pvec.pages[i];
+
+			if (!IS_DNODE(page))
+				continue;
+
+			lock_page(page);
+
+			if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
+continue_unlock:
+				unlock_page(page);
+				continue;
+			}
+
+			if (!PageDirty(page)) {
+				/* someone wrote it for us */
+				goto continue_unlock;
+			}
+
+			/* flush inline_data, if it's async context. */
+			if (is_inline_node(page)) {
+				clear_inline_node(page);
+				unlock_page(page);
+				flush_inline_data(sbi, ino_of_node(page));
+				continue;
+			}
+			unlock_page(page);
+		}
+		pagevec_release(&pvec);
+		cond_resched();
+	}
+}
+
+int f2fs_sync_node_pages(struct f2fs_sb_info *sbi,
+				struct writeback_control *wbc,
+				bool do_balance, enum iostat_type io_type)
+{
+	pgoff_t index;
+	struct pagevec pvec;
+	int step = 0;
+	int nwritten = 0;
+	int ret = 0;
+	int nr_pages, done = 0;
+
+	pagevec_init(&pvec);
+
+next_step:
+	index = 0;
+
+	while (!done && (nr_pages = pagevec_lookup_tag(&pvec,
+			NODE_MAPPING(sbi), &index, PAGECACHE_TAG_DIRTY))) {
+		int i;
+
+		for (i = 0; i < nr_pages; i++) {
+			struct page *page = pvec.pages[i];
+			bool submitted = false;
+			bool may_dirty = true;
+
+			/* give a priority to WB_SYNC threads */
+			if (atomic_read(&sbi->wb_sync_req[NODE]) &&
+					wbc->sync_mode == WB_SYNC_NONE) {
+				done = 1;
+				break;
+			}
+
+			/*
+			 * flushing sequence with step:
+			 * 0. indirect nodes
+			 * 1. dentry dnodes
+			 * 2. file dnodes
+			 */
+			if (step == 0 && IS_DNODE(page))
+				continue;
+			if (step == 1 && (!IS_DNODE(page) ||
+						is_cold_node(page)))
+				continue;
+			if (step == 2 && (!IS_DNODE(page) ||
+						!is_cold_node(page)))
+				continue;
+lock_node:
+			if (wbc->sync_mode == WB_SYNC_ALL)
+				lock_page(page);
+			else if (!trylock_page(page))
+				continue;
+
+			if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
+continue_unlock:
+				unlock_page(page);
+				continue;
+			}
+
+			if (!PageDirty(page)) {
+				/* someone wrote it for us */
+				goto continue_unlock;
+			}
+
+			/* flush inline_data/inode, if it's async context. */
+			if (!do_balance)
+				goto write_node;
+
+			/* flush inline_data */
+			if (is_inline_node(page)) {
+				clear_inline_node(page);
+				unlock_page(page);
+				flush_inline_data(sbi, ino_of_node(page));
+				goto lock_node;
+			}
+
+			/* flush dirty inode */
+			if (IS_INODE(page) && may_dirty) {
+				may_dirty = false;
+				if (flush_dirty_inode(page))
+					goto lock_node;
+			}
+write_node:
+			f2fs_wait_on_page_writeback(page, NODE, true, true);
+
+			if (!clear_page_dirty_for_io(page))
+				goto continue_unlock;
+
+			set_fsync_mark(page, 0);
+			set_dentry_mark(page, 0);
+
+			ret = __write_node_page(page, false, &submitted,
+						wbc, do_balance, io_type, NULL);
+			if (ret)
+				unlock_page(page);
+			else if (submitted)
+				nwritten++;
+
+			if (--wbc->nr_to_write == 0)
+				break;
+		}
+		pagevec_release(&pvec);
+		cond_resched();
+
+		if (wbc->nr_to_write == 0) {
+			step = 2;
+			break;
+		}
+	}
+
+	if (step < 2) {
+		if (!is_sbi_flag_set(sbi, SBI_CP_DISABLED) &&
+				wbc->sync_mode == WB_SYNC_NONE && step == 1)
+			goto out;
+		step++;
+		goto next_step;
+	}
+out:
+	if (nwritten)
+		f2fs_submit_merged_write(sbi, NODE);
+
+	if (unlikely(f2fs_cp_error(sbi)))
+		return -EIO;
+	return ret;
+}
+
+int f2fs_wait_on_node_pages_writeback(struct f2fs_sb_info *sbi,
+						unsigned int seq_id)
+{
+	struct fsync_node_entry *fn;
+	struct page *page;
+	struct list_head *head = &sbi->fsync_node_list;
+	unsigned long flags;
+	unsigned int cur_seq_id = 0;
+	int ret2, ret = 0;
+
+	while (seq_id && cur_seq_id < seq_id) {
+		spin_lock_irqsave(&sbi->fsync_node_lock, flags);
+		if (list_empty(head)) {
+			spin_unlock_irqrestore(&sbi->fsync_node_lock, flags);
+			break;
+		}
+		fn = list_first_entry(head, struct fsync_node_entry, list);
+		if (fn->seq_id > seq_id) {
+			spin_unlock_irqrestore(&sbi->fsync_node_lock, flags);
+			break;
+		}
+		cur_seq_id = fn->seq_id;
+		page = fn->page;
+		get_page(page);
+		spin_unlock_irqrestore(&sbi->fsync_node_lock, flags);
+
+		f2fs_wait_on_page_writeback(page, NODE, true, false);
+		if (TestClearPageError(page))
+			ret = -EIO;
+
+		put_page(page);
+
+		if (ret)
+			break;
+	}
+
+	ret2 = filemap_check_errors(NODE_MAPPING(sbi));
+	if (!ret)
+		ret = ret2;
+
+	return ret;
+}
+
+static int f2fs_write_node_pages(struct address_space *mapping,
+			    struct writeback_control *wbc)
+{
+	struct f2fs_sb_info *sbi = F2FS_M_SB(mapping);
+	struct blk_plug plug;
+	long diff;
+
+	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
+		goto skip_write;
+
+	/* balancing f2fs's metadata in background */
+	f2fs_balance_fs_bg(sbi, true);
+
+	/* collect a number of dirty node pages and write together */
+	if (wbc->sync_mode != WB_SYNC_ALL &&
+			get_pages(sbi, F2FS_DIRTY_NODES) <
+					nr_pages_to_skip(sbi, NODE))
+		goto skip_write;
+
+	if (wbc->sync_mode == WB_SYNC_ALL)
+		atomic_inc(&sbi->wb_sync_req[NODE]);
+	else if (atomic_read(&sbi->wb_sync_req[NODE])) {
+		/* to avoid potential deadlock */
+		if (current->plug)
+			blk_finish_plug(current->plug);
+		goto skip_write;
+	}
+
+	trace_f2fs_writepages(mapping->host, wbc, NODE);
+
+	diff = nr_pages_to_write(sbi, NODE, wbc);
+	blk_start_plug(&plug);
+	f2fs_sync_node_pages(sbi, wbc, true, FS_NODE_IO);
+	blk_finish_plug(&plug);
+	wbc->nr_to_write = max((long)0, wbc->nr_to_write - diff);
+
+	if (wbc->sync_mode == WB_SYNC_ALL)
+		atomic_dec(&sbi->wb_sync_req[NODE]);
+	return 0;
+
+skip_write:
+	wbc->pages_skipped += get_pages(sbi, F2FS_DIRTY_NODES);
+	trace_f2fs_writepages(mapping->host, wbc, NODE);
+	return 0;
+}
+
+static int f2fs_set_node_page_dirty(struct page *page)
+{
+	trace_f2fs_set_page_dirty(page, NODE);
+
+	if (!PageUptodate(page))
+		SetPageUptodate(page);
+#ifdef CONFIG_F2FS_CHECK_FS
+	if (IS_INODE(page))
+		f2fs_inode_chksum_set(F2FS_P_SB(page), page);
+#endif
+	if (!PageDirty(page)) {
+		__set_page_dirty_nobuffers(page);
+		inc_page_count(F2FS_P_SB(page), F2FS_DIRTY_NODES);
+		f2fs_set_page_private(page, 0);
+		f2fs_trace_pid(page);
+		return 1;
+	}
+	return 0;
+}
+
+/*
+ * Structure of the f2fs node operations
+ */
+const struct address_space_operations f2fs_node_aops = {
+	.writepage	= f2fs_write_node_page,
+	.writepages	= f2fs_write_node_pages,
+	.set_page_dirty	= f2fs_set_node_page_dirty,
+	.invalidatepage	= f2fs_invalidate_page,
+	.releasepage	= f2fs_release_page,
+#ifdef CONFIG_MIGRATION
+	.migratepage	= f2fs_migrate_page,
+#endif
+};
+
+static struct free_nid *__lookup_free_nid_list(struct f2fs_nm_info *nm_i,
+						nid_t n)
+{
+	return radix_tree_lookup(&nm_i->free_nid_root, n);
+}
+
+static int __insert_free_nid(struct f2fs_sb_info *sbi,
+				struct free_nid *i)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+
+	int err = radix_tree_insert(&nm_i->free_nid_root, i->nid, i);
+	if (err)
+		return err;
+
+	nm_i->nid_cnt[FREE_NID]++;
+	list_add_tail(&i->list, &nm_i->free_nid_list);
+	return 0;
+}
+
+static void __remove_free_nid(struct f2fs_sb_info *sbi,
+			struct free_nid *i, enum nid_state state)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+
+	f2fs_bug_on(sbi, state != i->state);
+	nm_i->nid_cnt[state]--;
+	if (state == FREE_NID)
+		list_del(&i->list);
+	radix_tree_delete(&nm_i->free_nid_root, i->nid);
+}
+
+static void __move_free_nid(struct f2fs_sb_info *sbi, struct free_nid *i,
+			enum nid_state org_state, enum nid_state dst_state)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+
+	f2fs_bug_on(sbi, org_state != i->state);
+	i->state = dst_state;
+	nm_i->nid_cnt[org_state]--;
+	nm_i->nid_cnt[dst_state]++;
+
+	switch (dst_state) {
+	case PREALLOC_NID:
+		list_del(&i->list);
+		break;
+	case FREE_NID:
+		list_add_tail(&i->list, &nm_i->free_nid_list);
+		break;
+	default:
+		BUG_ON(1);
+	}
+}
+
+static void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid,
+							bool set, bool build)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	unsigned int nat_ofs = NAT_BLOCK_OFFSET(nid);
+	unsigned int nid_ofs = nid - START_NID(nid);
+
+	if (!test_bit_le(nat_ofs, nm_i->nat_block_bitmap))
+		return;
+
+	if (set) {
+		if (test_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]))
+			return;
+		__set_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]);
+		nm_i->free_nid_count[nat_ofs]++;
+	} else {
+		if (!test_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]))
+			return;
+		__clear_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]);
+		if (!build)
+			nm_i->free_nid_count[nat_ofs]--;
+	}
+}
+
+/* return if the nid is recognized as free */
+static bool add_free_nid(struct f2fs_sb_info *sbi,
+				nid_t nid, bool build, bool update)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct free_nid *i, *e;
+	struct nat_entry *ne;
+	int err = -EINVAL;
+	bool ret = false;
+
+	/* 0 nid should not be used */
+	if (unlikely(nid == 0))
+		return false;
+
+	if (unlikely(f2fs_check_nid_range(sbi, nid)))
+		return false;
+
+	i = f2fs_kmem_cache_alloc(free_nid_slab, GFP_NOFS);
+	i->nid = nid;
+	i->state = FREE_NID;
+
+	radix_tree_preload(GFP_NOFS | __GFP_NOFAIL);
+
+	spin_lock(&nm_i->nid_list_lock);
+
+	if (build) {
+		/*
+		 *   Thread A             Thread B
+		 *  - f2fs_create
+		 *   - f2fs_new_inode
+		 *    - f2fs_alloc_nid
+		 *     - __insert_nid_to_list(PREALLOC_NID)
+		 *                     - f2fs_balance_fs_bg
+		 *                      - f2fs_build_free_nids
+		 *                       - __f2fs_build_free_nids
+		 *                        - scan_nat_page
+		 *                         - add_free_nid
+		 *                          - __lookup_nat_cache
+		 *  - f2fs_add_link
+		 *   - f2fs_init_inode_metadata
+		 *    - f2fs_new_inode_page
+		 *     - f2fs_new_node_page
+		 *      - set_node_addr
+		 *  - f2fs_alloc_nid_done
+		 *   - __remove_nid_from_list(PREALLOC_NID)
+		 *                         - __insert_nid_to_list(FREE_NID)
+		 */
+		ne = __lookup_nat_cache(nm_i, nid);
+		if (ne && (!get_nat_flag(ne, IS_CHECKPOINTED) ||
+				nat_get_blkaddr(ne) != NULL_ADDR))
+			goto err_out;
+
+		e = __lookup_free_nid_list(nm_i, nid);
+		if (e) {
+			if (e->state == FREE_NID)
+				ret = true;
+			goto err_out;
+		}
+	}
+	ret = true;
+	err = __insert_free_nid(sbi, i);
+err_out:
+	if (update) {
+		update_free_nid_bitmap(sbi, nid, ret, build);
+		if (!build)
+			nm_i->available_nids++;
+	}
+	spin_unlock(&nm_i->nid_list_lock);
+	radix_tree_preload_end();
+
+	if (err)
+		kmem_cache_free(free_nid_slab, i);
+	return ret;
+}
+
+static void remove_free_nid(struct f2fs_sb_info *sbi, nid_t nid)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct free_nid *i;
+	bool need_free = false;
+
+	spin_lock(&nm_i->nid_list_lock);
+	i = __lookup_free_nid_list(nm_i, nid);
+	if (i && i->state == FREE_NID) {
+		__remove_free_nid(sbi, i, FREE_NID);
+		need_free = true;
+	}
+	spin_unlock(&nm_i->nid_list_lock);
+
+	if (need_free)
+		kmem_cache_free(free_nid_slab, i);
+}
+
+static int scan_nat_page(struct f2fs_sb_info *sbi,
+			struct page *nat_page, nid_t start_nid)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct f2fs_nat_block *nat_blk = page_address(nat_page);
+	block_t blk_addr;
+	unsigned int nat_ofs = NAT_BLOCK_OFFSET(start_nid);
+	int i;
+
+	__set_bit_le(nat_ofs, nm_i->nat_block_bitmap);
+
+	i = start_nid % NAT_ENTRY_PER_BLOCK;
+
+	for (; i < NAT_ENTRY_PER_BLOCK; i++, start_nid++) {
+		if (unlikely(start_nid >= nm_i->max_nid))
+			break;
+
+		blk_addr = le32_to_cpu(nat_blk->entries[i].block_addr);
+
+		if (blk_addr == NEW_ADDR)
+			return -EINVAL;
+
+		if (blk_addr == NULL_ADDR) {
+			add_free_nid(sbi, start_nid, true, true);
+		} else {
+			spin_lock(&NM_I(sbi)->nid_list_lock);
+			update_free_nid_bitmap(sbi, start_nid, false, true);
+			spin_unlock(&NM_I(sbi)->nid_list_lock);
+		}
+	}
+
+	return 0;
+}
+
+static void scan_curseg_cache(struct f2fs_sb_info *sbi)
+{
+	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
+	struct f2fs_journal *journal = curseg->journal;
+	int i;
+
+	down_read(&curseg->journal_rwsem);
+	for (i = 0; i < nats_in_cursum(journal); i++) {
+		block_t addr;
+		nid_t nid;
+
+		addr = le32_to_cpu(nat_in_journal(journal, i).block_addr);
+		nid = le32_to_cpu(nid_in_journal(journal, i));
+		if (addr == NULL_ADDR)
+			add_free_nid(sbi, nid, true, false);
+		else
+			remove_free_nid(sbi, nid);
+	}
+	up_read(&curseg->journal_rwsem);
+}
+
+static void scan_free_nid_bits(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	unsigned int i, idx;
+	nid_t nid;
+
+	down_read(&nm_i->nat_tree_lock);
+
+	for (i = 0; i < nm_i->nat_blocks; i++) {
+		if (!test_bit_le(i, nm_i->nat_block_bitmap))
+			continue;
+		if (!nm_i->free_nid_count[i])
+			continue;
+		for (idx = 0; idx < NAT_ENTRY_PER_BLOCK; idx++) {
+			idx = find_next_bit_le(nm_i->free_nid_bitmap[i],
+						NAT_ENTRY_PER_BLOCK, idx);
+			if (idx >= NAT_ENTRY_PER_BLOCK)
+				break;
+
+			nid = i * NAT_ENTRY_PER_BLOCK + idx;
+			add_free_nid(sbi, nid, true, false);
+
+			if (nm_i->nid_cnt[FREE_NID] >= MAX_FREE_NIDS)
+				goto out;
+		}
+	}
+out:
+	scan_curseg_cache(sbi);
+
+	up_read(&nm_i->nat_tree_lock);
+}
+
+static int __f2fs_build_free_nids(struct f2fs_sb_info *sbi,
+						bool sync, bool mount)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	int i = 0, ret;
+	nid_t nid = nm_i->next_scan_nid;
+
+	if (unlikely(nid >= nm_i->max_nid))
+		nid = 0;
+
+	if (unlikely(nid % NAT_ENTRY_PER_BLOCK))
+		nid = NAT_BLOCK_OFFSET(nid) * NAT_ENTRY_PER_BLOCK;
+
+	/* Enough entries */
+	if (nm_i->nid_cnt[FREE_NID] >= NAT_ENTRY_PER_BLOCK)
+		return 0;
+
+	if (!sync && !f2fs_available_free_memory(sbi, FREE_NIDS))
+		return 0;
+
+	if (!mount) {
+		/* try to find free nids in free_nid_bitmap */
+		scan_free_nid_bits(sbi);
+
+		if (nm_i->nid_cnt[FREE_NID] >= NAT_ENTRY_PER_BLOCK)
+			return 0;
+	}
+
+	/* readahead nat pages to be scanned */
+	f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), FREE_NID_PAGES,
+							META_NAT, true);
+
+	down_read(&nm_i->nat_tree_lock);
+
+	while (1) {
+		if (!test_bit_le(NAT_BLOCK_OFFSET(nid),
+						nm_i->nat_block_bitmap)) {
+			struct page *page = get_current_nat_page(sbi, nid);
+
+			if (IS_ERR(page)) {
+				ret = PTR_ERR(page);
+			} else {
+				ret = scan_nat_page(sbi, page, nid);
+				f2fs_put_page(page, 1);
+			}
+
+			if (ret) {
+				up_read(&nm_i->nat_tree_lock);
+				f2fs_err(sbi, "NAT is corrupt, run fsck to fix it");
+				return ret;
+			}
+		}
+
+		nid += (NAT_ENTRY_PER_BLOCK - (nid % NAT_ENTRY_PER_BLOCK));
+		if (unlikely(nid >= nm_i->max_nid))
+			nid = 0;
+
+		if (++i >= FREE_NID_PAGES)
+			break;
+	}
+
+	/* go to the next free nat pages to find free nids abundantly */
+	nm_i->next_scan_nid = nid;
+
+	/* find free nids from current sum_pages */
+	scan_curseg_cache(sbi);
+
+	up_read(&nm_i->nat_tree_lock);
+
+	f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nm_i->next_scan_nid),
+					nm_i->ra_nid_pages, META_NAT, false);
+
+	return 0;
+}
+
+int f2fs_build_free_nids(struct f2fs_sb_info *sbi, bool sync, bool mount)
+{
+	int ret;
+
+	mutex_lock(&NM_I(sbi)->build_lock);
+	ret = __f2fs_build_free_nids(sbi, sync, mount);
+	mutex_unlock(&NM_I(sbi)->build_lock);
+
+	return ret;
+}
+
+/*
+ * If this function returns success, caller can obtain a new nid
+ * from second parameter of this function.
+ * The returned nid could be used ino as well as nid when inode is created.
+ */
+bool f2fs_alloc_nid(struct f2fs_sb_info *sbi, nid_t *nid)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct free_nid *i = NULL;
+retry:
+	if (time_to_inject(sbi, FAULT_ALLOC_NID)) {
+		f2fs_show_injection_info(sbi, FAULT_ALLOC_NID);
+		return false;
+	}
+
+	spin_lock(&nm_i->nid_list_lock);
+
+	if (unlikely(nm_i->available_nids == 0)) {
+		spin_unlock(&nm_i->nid_list_lock);
+		return false;
+	}
+
+	/* We should not use stale free nids created by f2fs_build_free_nids */
+	if (nm_i->nid_cnt[FREE_NID] && !on_f2fs_build_free_nids(nm_i)) {
+		f2fs_bug_on(sbi, list_empty(&nm_i->free_nid_list));
+		i = list_first_entry(&nm_i->free_nid_list,
+					struct free_nid, list);
+		*nid = i->nid;
+
+		__move_free_nid(sbi, i, FREE_NID, PREALLOC_NID);
+		nm_i->available_nids--;
+
+		update_free_nid_bitmap(sbi, *nid, false, false);
+
+		spin_unlock(&nm_i->nid_list_lock);
+		return true;
+	}
+	spin_unlock(&nm_i->nid_list_lock);
+
+	/* Let's scan nat pages and its caches to get free nids */
+	if (!f2fs_build_free_nids(sbi, true, false))
+		goto retry;
+	return false;
+}
+
+/*
+ * f2fs_alloc_nid() should be called prior to this function.
+ */
+void f2fs_alloc_nid_done(struct f2fs_sb_info *sbi, nid_t nid)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct free_nid *i;
+
+	spin_lock(&nm_i->nid_list_lock);
+	i = __lookup_free_nid_list(nm_i, nid);
+	f2fs_bug_on(sbi, !i);
+	__remove_free_nid(sbi, i, PREALLOC_NID);
+	spin_unlock(&nm_i->nid_list_lock);
+
+	kmem_cache_free(free_nid_slab, i);
+}
+
+/*
+ * f2fs_alloc_nid() should be called prior to this function.
+ */
+void f2fs_alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct free_nid *i;
+	bool need_free = false;
+
+	if (!nid)
+		return;
+
+	spin_lock(&nm_i->nid_list_lock);
+	i = __lookup_free_nid_list(nm_i, nid);
+	f2fs_bug_on(sbi, !i);
+
+	if (!f2fs_available_free_memory(sbi, FREE_NIDS)) {
+		__remove_free_nid(sbi, i, PREALLOC_NID);
+		need_free = true;
+	} else {
+		__move_free_nid(sbi, i, PREALLOC_NID, FREE_NID);
+	}
+
+	nm_i->available_nids++;
+
+	update_free_nid_bitmap(sbi, nid, true, false);
+
+	spin_unlock(&nm_i->nid_list_lock);
+
+	if (need_free)
+		kmem_cache_free(free_nid_slab, i);
+}
+
+int f2fs_try_to_free_nids(struct f2fs_sb_info *sbi, int nr_shrink)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	int nr = nr_shrink;
+
+	if (nm_i->nid_cnt[FREE_NID] <= MAX_FREE_NIDS)
+		return 0;
+
+	if (!mutex_trylock(&nm_i->build_lock))
+		return 0;
+
+	while (nr_shrink && nm_i->nid_cnt[FREE_NID] > MAX_FREE_NIDS) {
+		struct free_nid *i, *next;
+		unsigned int batch = SHRINK_NID_BATCH_SIZE;
+
+		spin_lock(&nm_i->nid_list_lock);
+		list_for_each_entry_safe(i, next, &nm_i->free_nid_list, list) {
+			if (!nr_shrink || !batch ||
+				nm_i->nid_cnt[FREE_NID] <= MAX_FREE_NIDS)
+				break;
+			__remove_free_nid(sbi, i, FREE_NID);
+			kmem_cache_free(free_nid_slab, i);
+			nr_shrink--;
+			batch--;
+		}
+		spin_unlock(&nm_i->nid_list_lock);
+	}
+
+	mutex_unlock(&nm_i->build_lock);
+
+	return nr - nr_shrink;
+}
+
+int f2fs_recover_inline_xattr(struct inode *inode, struct page *page)
+{
+	void *src_addr, *dst_addr;
+	size_t inline_size;
+	struct page *ipage;
+	struct f2fs_inode *ri;
+
+	ipage = f2fs_get_node_page(F2FS_I_SB(inode), inode->i_ino);
+	if (IS_ERR(ipage))
+		return PTR_ERR(ipage);
+
+	ri = F2FS_INODE(page);
+	if (ri->i_inline & F2FS_INLINE_XATTR) {
+		set_inode_flag(inode, FI_INLINE_XATTR);
+	} else {
+		clear_inode_flag(inode, FI_INLINE_XATTR);
+		goto update_inode;
+	}
+
+	dst_addr = inline_xattr_addr(inode, ipage);
+	src_addr = inline_xattr_addr(inode, page);
+	inline_size = inline_xattr_size(inode);
+
+	f2fs_wait_on_page_writeback(ipage, NODE, true, true);
+	memcpy(dst_addr, src_addr, inline_size);
+update_inode:
+	f2fs_update_inode(inode, ipage);
+	f2fs_put_page(ipage, 1);
+	return 0;
+}
+
+int f2fs_recover_xattr_data(struct inode *inode, struct page *page)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	nid_t prev_xnid = F2FS_I(inode)->i_xattr_nid;
+	nid_t new_xnid;
+	struct dnode_of_data dn;
+	struct node_info ni;
+	struct page *xpage;
+	int err;
+
+	if (!prev_xnid)
+		goto recover_xnid;
+
+	/* 1: invalidate the previous xattr nid */
+	err = f2fs_get_node_info(sbi, prev_xnid, &ni);
+	if (err)
+		return err;
+
+	f2fs_invalidate_blocks(sbi, ni.blk_addr);
+	dec_valid_node_count(sbi, inode, false);
+	set_node_addr(sbi, &ni, NULL_ADDR, false);
+
+recover_xnid:
+	/* 2: update xattr nid in inode */
+	if (!f2fs_alloc_nid(sbi, &new_xnid))
+		return -ENOSPC;
+
+	set_new_dnode(&dn, inode, NULL, NULL, new_xnid);
+	xpage = f2fs_new_node_page(&dn, XATTR_NODE_OFFSET);
+	if (IS_ERR(xpage)) {
+		f2fs_alloc_nid_failed(sbi, new_xnid);
+		return PTR_ERR(xpage);
+	}
+
+	f2fs_alloc_nid_done(sbi, new_xnid);
+	f2fs_update_inode_page(inode);
+
+	/* 3: update and set xattr node page dirty */
+	memcpy(F2FS_NODE(xpage), F2FS_NODE(page), VALID_XATTR_BLOCK_SIZE);
+
+	set_page_dirty(xpage);
+	f2fs_put_page(xpage, 1);
+
+	return 0;
+}
+
+int f2fs_recover_inode_page(struct f2fs_sb_info *sbi, struct page *page)
+{
+	struct f2fs_inode *src, *dst;
+	nid_t ino = ino_of_node(page);
+	struct node_info old_ni, new_ni;
+	struct page *ipage;
+	int err;
+
+	err = f2fs_get_node_info(sbi, ino, &old_ni);
+	if (err)
+		return err;
+
+	if (unlikely(old_ni.blk_addr != NULL_ADDR))
+		return -EINVAL;
+retry:
+	ipage = f2fs_grab_cache_page(NODE_MAPPING(sbi), ino, false);
+	if (!ipage) {
+		congestion_wait(BLK_RW_ASYNC, DEFAULT_IO_TIMEOUT);
+		goto retry;
+	}
+
+	/* Should not use this inode from free nid list */
+	remove_free_nid(sbi, ino);
+
+	if (!PageUptodate(ipage))
+		SetPageUptodate(ipage);
+	fill_node_footer(ipage, ino, ino, 0, true);
+	set_cold_node(ipage, false);
+
+	src = F2FS_INODE(page);
+	dst = F2FS_INODE(ipage);
+
+	memcpy(dst, src, (unsigned long)&src->i_ext - (unsigned long)src);
+	dst->i_size = 0;
+	dst->i_blocks = cpu_to_le64(1);
+	dst->i_links = cpu_to_le32(1);
+	dst->i_xattr_nid = 0;
+	dst->i_inline = src->i_inline & (F2FS_INLINE_XATTR | F2FS_EXTRA_ATTR);
+	if (dst->i_inline & F2FS_EXTRA_ATTR) {
+		dst->i_extra_isize = src->i_extra_isize;
+
+		if (f2fs_sb_has_flexible_inline_xattr(sbi) &&
+			F2FS_FITS_IN_INODE(src, le16_to_cpu(src->i_extra_isize),
+							i_inline_xattr_size))
+			dst->i_inline_xattr_size = src->i_inline_xattr_size;
+
+		if (f2fs_sb_has_project_quota(sbi) &&
+			F2FS_FITS_IN_INODE(src, le16_to_cpu(src->i_extra_isize),
+								i_projid))
+			dst->i_projid = src->i_projid;
+
+		if (f2fs_sb_has_inode_crtime(sbi) &&
+			F2FS_FITS_IN_INODE(src, le16_to_cpu(src->i_extra_isize),
+							i_crtime_nsec)) {
+			dst->i_crtime = src->i_crtime;
+			dst->i_crtime_nsec = src->i_crtime_nsec;
+		}
+	}
+
+	new_ni = old_ni;
+	new_ni.ino = ino;
+
+	if (unlikely(inc_valid_node_count(sbi, NULL, true)))
+		WARN_ON(1);
+	set_node_addr(sbi, &new_ni, NEW_ADDR, false);
+	inc_valid_inode_count(sbi);
+	set_page_dirty(ipage);
+	f2fs_put_page(ipage, 1);
+	return 0;
+}
+
+int f2fs_restore_node_summary(struct f2fs_sb_info *sbi,
+			unsigned int segno, struct f2fs_summary_block *sum)
+{
+	struct f2fs_node *rn;
+	struct f2fs_summary *sum_entry;
+	block_t addr;
+	int i, idx, last_offset, nrpages;
+
+	/* scan the node segment */
+	last_offset = sbi->blocks_per_seg;
+	addr = START_BLOCK(sbi, segno);
+	sum_entry = &sum->entries[0];
+
+	for (i = 0; i < last_offset; i += nrpages, addr += nrpages) {
+		nrpages = min(last_offset - i, BIO_MAX_PAGES);
+
+		/* readahead node pages */
+		f2fs_ra_meta_pages(sbi, addr, nrpages, META_POR, true);
+
+		for (idx = addr; idx < addr + nrpages; idx++) {
+			struct page *page = f2fs_get_tmp_page(sbi, idx);
+
+			if (IS_ERR(page))
+				return PTR_ERR(page);
+
+			rn = F2FS_NODE(page);
+			sum_entry->nid = rn->footer.nid;
+			sum_entry->version = 0;
+			sum_entry->ofs_in_node = 0;
+			sum_entry++;
+			f2fs_put_page(page, 1);
+		}
+
+		invalidate_mapping_pages(META_MAPPING(sbi), addr,
+							addr + nrpages);
+	}
+	return 0;
+}
+
+static void remove_nats_in_journal(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
+	struct f2fs_journal *journal = curseg->journal;
+	int i;
+
+	down_write(&curseg->journal_rwsem);
+	for (i = 0; i < nats_in_cursum(journal); i++) {
+		struct nat_entry *ne;
+		struct f2fs_nat_entry raw_ne;
+		nid_t nid = le32_to_cpu(nid_in_journal(journal, i));
+
+		if (f2fs_check_nid_range(sbi, nid))
+			continue;
+
+		raw_ne = nat_in_journal(journal, i);
+
+		ne = __lookup_nat_cache(nm_i, nid);
+		if (!ne) {
+			ne = __alloc_nat_entry(nid, true);
+			__init_nat_entry(nm_i, ne, &raw_ne, true);
+		}
+
+		/*
+		 * if a free nat in journal has not been used after last
+		 * checkpoint, we should remove it from available nids,
+		 * since later we will add it again.
+		 */
+		if (!get_nat_flag(ne, IS_DIRTY) &&
+				le32_to_cpu(raw_ne.block_addr) == NULL_ADDR) {
+			spin_lock(&nm_i->nid_list_lock);
+			nm_i->available_nids--;
+			spin_unlock(&nm_i->nid_list_lock);
+		}
+
+		__set_nat_cache_dirty(nm_i, ne);
+	}
+	update_nats_in_cursum(journal, -i);
+	up_write(&curseg->journal_rwsem);
+}
+
+static void __adjust_nat_entry_set(struct nat_entry_set *nes,
+						struct list_head *head, int max)
+{
+	struct nat_entry_set *cur;
+
+	if (nes->entry_cnt >= max)
+		goto add_out;
+
+	list_for_each_entry(cur, head, set_list) {
+		if (cur->entry_cnt >= nes->entry_cnt) {
+			list_add(&nes->set_list, cur->set_list.prev);
+			return;
+		}
+	}
+add_out:
+	list_add_tail(&nes->set_list, head);
+}
+
+static void __update_nat_bits(struct f2fs_sb_info *sbi, nid_t start_nid,
+						struct page *page)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	unsigned int nat_index = start_nid / NAT_ENTRY_PER_BLOCK;
+	struct f2fs_nat_block *nat_blk = page_address(page);
+	int valid = 0;
+	int i = 0;
+
+	if (!enabled_nat_bits(sbi, NULL))
+		return;
+
+	if (nat_index == 0) {
+		valid = 1;
+		i = 1;
+	}
+	for (; i < NAT_ENTRY_PER_BLOCK; i++) {
+		if (le32_to_cpu(nat_blk->entries[i].block_addr) != NULL_ADDR)
+			valid++;
+	}
+	if (valid == 0) {
+		__set_bit_le(nat_index, nm_i->empty_nat_bits);
+		__clear_bit_le(nat_index, nm_i->full_nat_bits);
+		return;
+	}
+
+	__clear_bit_le(nat_index, nm_i->empty_nat_bits);
+	if (valid == NAT_ENTRY_PER_BLOCK)
+		__set_bit_le(nat_index, nm_i->full_nat_bits);
+	else
+		__clear_bit_le(nat_index, nm_i->full_nat_bits);
+}
+
+static int __flush_nat_entry_set(struct f2fs_sb_info *sbi,
+		struct nat_entry_set *set, struct cp_control *cpc)
+{
+	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
+	struct f2fs_journal *journal = curseg->journal;
+	nid_t start_nid = set->set * NAT_ENTRY_PER_BLOCK;
+	bool to_journal = true;
+	struct f2fs_nat_block *nat_blk;
+	struct nat_entry *ne, *cur;
+	struct page *page = NULL;
+
+	/*
+	 * there are two steps to flush nat entries:
+	 * #1, flush nat entries to journal in current hot data summary block.
+	 * #2, flush nat entries to nat page.
+	 */
+	if (enabled_nat_bits(sbi, cpc) ||
+		!__has_cursum_space(journal, set->entry_cnt, NAT_JOURNAL))
+		to_journal = false;
+
+	if (to_journal) {
+		down_write(&curseg->journal_rwsem);
+	} else {
+		page = get_next_nat_page(sbi, start_nid);
+		if (IS_ERR(page))
+			return PTR_ERR(page);
+
+		nat_blk = page_address(page);
+		f2fs_bug_on(sbi, !nat_blk);
+	}
+
+	/* flush dirty nats in nat entry set */
+	list_for_each_entry_safe(ne, cur, &set->entry_list, list) {
+		struct f2fs_nat_entry *raw_ne;
+		nid_t nid = nat_get_nid(ne);
+		int offset;
+
+		f2fs_bug_on(sbi, nat_get_blkaddr(ne) == NEW_ADDR);
+
+		if (to_journal) {
+			offset = f2fs_lookup_journal_in_cursum(journal,
+							NAT_JOURNAL, nid, 1);
+			f2fs_bug_on(sbi, offset < 0);
+			raw_ne = &nat_in_journal(journal, offset);
+			nid_in_journal(journal, offset) = cpu_to_le32(nid);
+		} else {
+			raw_ne = &nat_blk->entries[nid - start_nid];
+		}
+		raw_nat_from_node_info(raw_ne, &ne->ni);
+		nat_reset_flag(ne);
+		__clear_nat_cache_dirty(NM_I(sbi), set, ne);
+		if (nat_get_blkaddr(ne) == NULL_ADDR) {
+			add_free_nid(sbi, nid, false, true);
+		} else {
+			spin_lock(&NM_I(sbi)->nid_list_lock);
+			update_free_nid_bitmap(sbi, nid, false, false);
+			spin_unlock(&NM_I(sbi)->nid_list_lock);
+		}
+	}
+
+	if (to_journal) {
+		up_write(&curseg->journal_rwsem);
+	} else {
+		__update_nat_bits(sbi, start_nid, page);
+		f2fs_put_page(page, 1);
+	}
+
+	/* Allow dirty nats by node block allocation in write_begin */
+	if (!set->entry_cnt) {
+		radix_tree_delete(&NM_I(sbi)->nat_set_root, set->set);
+		kmem_cache_free(nat_entry_set_slab, set);
+	}
+	return 0;
+}
+
+/*
+ * This function is called during the checkpointing process.
+ */
+int f2fs_flush_nat_entries(struct f2fs_sb_info *sbi, struct cp_control *cpc)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
+	struct f2fs_journal *journal = curseg->journal;
+	struct nat_entry_set *setvec[SETVEC_SIZE];
+	struct nat_entry_set *set, *tmp;
+	unsigned int found;
+	nid_t set_idx = 0;
+	LIST_HEAD(sets);
+	int err = 0;
+
+	/*
+	 * during unmount, let's flush nat_bits before checking
+	 * nat_cnt[DIRTY_NAT].
+	 */
+	if (enabled_nat_bits(sbi, cpc)) {
+		down_write(&nm_i->nat_tree_lock);
+		remove_nats_in_journal(sbi);
+		up_write(&nm_i->nat_tree_lock);
+	}
+
+	if (!nm_i->nat_cnt[DIRTY_NAT])
+		return 0;
+
+	down_write(&nm_i->nat_tree_lock);
+
+	/*
+	 * if there are no enough space in journal to store dirty nat
+	 * entries, remove all entries from journal and merge them
+	 * into nat entry set.
+	 */
+	if (enabled_nat_bits(sbi, cpc) ||
+		!__has_cursum_space(journal,
+			nm_i->nat_cnt[DIRTY_NAT], NAT_JOURNAL))
+		remove_nats_in_journal(sbi);
+
+	while ((found = __gang_lookup_nat_set(nm_i,
+					set_idx, SETVEC_SIZE, setvec))) {
+		unsigned idx;
+		set_idx = setvec[found - 1]->set + 1;
+		for (idx = 0; idx < found; idx++)
+			__adjust_nat_entry_set(setvec[idx], &sets,
+						MAX_NAT_JENTRIES(journal));
+	}
+
+	/* flush dirty nats in nat entry set */
+	list_for_each_entry_safe(set, tmp, &sets, set_list) {
+		err = __flush_nat_entry_set(sbi, set, cpc);
+		if (err)
+			break;
+	}
+
+	up_write(&nm_i->nat_tree_lock);
+	/* Allow dirty nats by node block allocation in write_begin */
+
+	return err;
+}
+
+static int __get_nat_bitmaps(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	unsigned int nat_bits_bytes = nm_i->nat_blocks / BITS_PER_BYTE;
+	unsigned int i;
+	__u64 cp_ver = cur_cp_version(ckpt);
+	block_t nat_bits_addr;
+
+	if (!enabled_nat_bits(sbi, NULL))
+		return 0;
+
+	nm_i->nat_bits_blocks = F2FS_BLK_ALIGN((nat_bits_bytes << 1) + 8);
+	nm_i->nat_bits = f2fs_kvzalloc(sbi,
+			nm_i->nat_bits_blocks << F2FS_BLKSIZE_BITS, GFP_KERNEL);
+	if (!nm_i->nat_bits)
+		return -ENOMEM;
+
+	nat_bits_addr = __start_cp_addr(sbi) + sbi->blocks_per_seg -
+						nm_i->nat_bits_blocks;
+	for (i = 0; i < nm_i->nat_bits_blocks; i++) {
+		struct page *page;
+
+		page = f2fs_get_meta_page(sbi, nat_bits_addr++);
+		if (IS_ERR(page))
+			return PTR_ERR(page);
+
+		memcpy(nm_i->nat_bits + (i << F2FS_BLKSIZE_BITS),
+					page_address(page), F2FS_BLKSIZE);
+		f2fs_put_page(page, 1);
+	}
+
+	cp_ver |= (cur_cp_crc(ckpt) << 32);
+	if (cpu_to_le64(cp_ver) != *(__le64 *)nm_i->nat_bits) {
+		disable_nat_bits(sbi, true);
+		return 0;
+	}
+
+	nm_i->full_nat_bits = nm_i->nat_bits + 8;
+	nm_i->empty_nat_bits = nm_i->full_nat_bits + nat_bits_bytes;
+
+	f2fs_notice(sbi, "Found nat_bits in checkpoint");
+	return 0;
+}
+
+static inline void load_free_nid_bitmap(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	unsigned int i = 0;
+	nid_t nid, last_nid;
+
+	if (!enabled_nat_bits(sbi, NULL))
+		return;
+
+	for (i = 0; i < nm_i->nat_blocks; i++) {
+		i = find_next_bit_le(nm_i->empty_nat_bits, nm_i->nat_blocks, i);
+		if (i >= nm_i->nat_blocks)
+			break;
+
+		__set_bit_le(i, nm_i->nat_block_bitmap);
+
+		nid = i * NAT_ENTRY_PER_BLOCK;
+		last_nid = nid + NAT_ENTRY_PER_BLOCK;
+
+		spin_lock(&NM_I(sbi)->nid_list_lock);
+		for (; nid < last_nid; nid++)
+			update_free_nid_bitmap(sbi, nid, true, true);
+		spin_unlock(&NM_I(sbi)->nid_list_lock);
+	}
+
+	for (i = 0; i < nm_i->nat_blocks; i++) {
+		i = find_next_bit_le(nm_i->full_nat_bits, nm_i->nat_blocks, i);
+		if (i >= nm_i->nat_blocks)
+			break;
+
+		__set_bit_le(i, nm_i->nat_block_bitmap);
+	}
+}
+
+static int init_node_manager(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_super_block *sb_raw = F2FS_RAW_SUPER(sbi);
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	unsigned char *version_bitmap;
+	unsigned int nat_segs;
+	int err;
+
+	nm_i->nat_blkaddr = le32_to_cpu(sb_raw->nat_blkaddr);
+
+	/* segment_count_nat includes pair segment so divide to 2. */
+	nat_segs = le32_to_cpu(sb_raw->segment_count_nat) >> 1;
+	nm_i->nat_blocks = nat_segs << le32_to_cpu(sb_raw->log_blocks_per_seg);
+	nm_i->max_nid = NAT_ENTRY_PER_BLOCK * nm_i->nat_blocks;
+
+	/* not used nids: 0, node, meta, (and root counted as valid node) */
+	nm_i->available_nids = nm_i->max_nid - sbi->total_valid_node_count -
+						F2FS_RESERVED_NODE_NUM;
+	nm_i->nid_cnt[FREE_NID] = 0;
+	nm_i->nid_cnt[PREALLOC_NID] = 0;
+	nm_i->ram_thresh = DEF_RAM_THRESHOLD;
+	nm_i->ra_nid_pages = DEF_RA_NID_PAGES;
+	nm_i->dirty_nats_ratio = DEF_DIRTY_NAT_RATIO_THRESHOLD;
+
+	INIT_RADIX_TREE(&nm_i->free_nid_root, GFP_ATOMIC);
+	INIT_LIST_HEAD(&nm_i->free_nid_list);
+	INIT_RADIX_TREE(&nm_i->nat_root, GFP_NOIO);
+	INIT_RADIX_TREE(&nm_i->nat_set_root, GFP_NOIO);
+	INIT_LIST_HEAD(&nm_i->nat_entries);
+	spin_lock_init(&nm_i->nat_list_lock);
+
+	mutex_init(&nm_i->build_lock);
+	spin_lock_init(&nm_i->nid_list_lock);
+	init_rwsem(&nm_i->nat_tree_lock);
+
+	nm_i->next_scan_nid = le32_to_cpu(sbi->ckpt->next_free_nid);
+	nm_i->bitmap_size = __bitmap_size(sbi, NAT_BITMAP);
+	version_bitmap = __bitmap_ptr(sbi, NAT_BITMAP);
+	nm_i->nat_bitmap = kmemdup(version_bitmap, nm_i->bitmap_size,
+					GFP_KERNEL);
+	if (!nm_i->nat_bitmap)
+		return -ENOMEM;
+
+	err = __get_nat_bitmaps(sbi);
+	if (err)
+		return err;
+
+#ifdef CONFIG_F2FS_CHECK_FS
+	nm_i->nat_bitmap_mir = kmemdup(version_bitmap, nm_i->bitmap_size,
+					GFP_KERNEL);
+	if (!nm_i->nat_bitmap_mir)
+		return -ENOMEM;
+#endif
+
+	return 0;
+}
+
+static int init_free_nid_cache(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	int i;
+
+	nm_i->free_nid_bitmap =
+		f2fs_kvzalloc(sbi, array_size(sizeof(unsigned char *),
+					      nm_i->nat_blocks),
+			      GFP_KERNEL);
+	if (!nm_i->free_nid_bitmap)
+		return -ENOMEM;
+
+	for (i = 0; i < nm_i->nat_blocks; i++) {
+		nm_i->free_nid_bitmap[i] = f2fs_kvzalloc(sbi,
+			f2fs_bitmap_size(NAT_ENTRY_PER_BLOCK), GFP_KERNEL);
+		if (!nm_i->free_nid_bitmap[i])
+			return -ENOMEM;
+	}
+
+	nm_i->nat_block_bitmap = f2fs_kvzalloc(sbi, nm_i->nat_blocks / 8,
+								GFP_KERNEL);
+	if (!nm_i->nat_block_bitmap)
+		return -ENOMEM;
+
+	nm_i->free_nid_count =
+		f2fs_kvzalloc(sbi, array_size(sizeof(unsigned short),
+					      nm_i->nat_blocks),
+			      GFP_KERNEL);
+	if (!nm_i->free_nid_count)
+		return -ENOMEM;
+	return 0;
+}
+
+int f2fs_build_node_manager(struct f2fs_sb_info *sbi)
+{
+	int err;
+
+	sbi->nm_info = f2fs_kzalloc(sbi, sizeof(struct f2fs_nm_info),
+							GFP_KERNEL);
+	if (!sbi->nm_info)
+		return -ENOMEM;
+
+	err = init_node_manager(sbi);
+	if (err)
+		return err;
+
+	err = init_free_nid_cache(sbi);
+	if (err)
+		return err;
+
+	/* load free nid status from nat_bits table */
+	load_free_nid_bitmap(sbi);
+
+	return f2fs_build_free_nids(sbi, true, true);
+}
+
+void f2fs_destroy_node_manager(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct free_nid *i, *next_i;
+	struct nat_entry *natvec[NATVEC_SIZE];
+	struct nat_entry_set *setvec[SETVEC_SIZE];
+	nid_t nid = 0;
+	unsigned int found;
+
+	if (!nm_i)
+		return;
+
+	/* destroy free nid list */
+	spin_lock(&nm_i->nid_list_lock);
+	list_for_each_entry_safe(i, next_i, &nm_i->free_nid_list, list) {
+		__remove_free_nid(sbi, i, FREE_NID);
+		spin_unlock(&nm_i->nid_list_lock);
+		kmem_cache_free(free_nid_slab, i);
+		spin_lock(&nm_i->nid_list_lock);
+	}
+	f2fs_bug_on(sbi, nm_i->nid_cnt[FREE_NID]);
+	f2fs_bug_on(sbi, nm_i->nid_cnt[PREALLOC_NID]);
+	f2fs_bug_on(sbi, !list_empty(&nm_i->free_nid_list));
+	spin_unlock(&nm_i->nid_list_lock);
+
+	/* destroy nat cache */
+	down_write(&nm_i->nat_tree_lock);
+	while ((found = __gang_lookup_nat_cache(nm_i,
+					nid, NATVEC_SIZE, natvec))) {
+		unsigned idx;
+
+		nid = nat_get_nid(natvec[found - 1]) + 1;
+		for (idx = 0; idx < found; idx++) {
+			spin_lock(&nm_i->nat_list_lock);
+			list_del(&natvec[idx]->list);
+			spin_unlock(&nm_i->nat_list_lock);
+
+			__del_from_nat_cache(nm_i, natvec[idx]);
+		}
+	}
+	f2fs_bug_on(sbi, nm_i->nat_cnt[TOTAL_NAT]);
+
+	/* destroy nat set cache */
+	nid = 0;
+	while ((found = __gang_lookup_nat_set(nm_i,
+					nid, SETVEC_SIZE, setvec))) {
+		unsigned idx;
+
+		nid = setvec[found - 1]->set + 1;
+		for (idx = 0; idx < found; idx++) {
+			/* entry_cnt is not zero, when cp_error was occurred */
+			f2fs_bug_on(sbi, !list_empty(&setvec[idx]->entry_list));
+			radix_tree_delete(&nm_i->nat_set_root, setvec[idx]->set);
+			kmem_cache_free(nat_entry_set_slab, setvec[idx]);
+		}
+	}
+	up_write(&nm_i->nat_tree_lock);
+
+	kvfree(nm_i->nat_block_bitmap);
+	if (nm_i->free_nid_bitmap) {
+		int i;
+
+		for (i = 0; i < nm_i->nat_blocks; i++)
+			kvfree(nm_i->free_nid_bitmap[i]);
+		kvfree(nm_i->free_nid_bitmap);
+	}
+	kvfree(nm_i->free_nid_count);
+
+	kvfree(nm_i->nat_bitmap);
+	kvfree(nm_i->nat_bits);
+#ifdef CONFIG_F2FS_CHECK_FS
+	kvfree(nm_i->nat_bitmap_mir);
+#endif
+	sbi->nm_info = NULL;
+	kfree(nm_i);
+}
+
+int __init f2fs_create_node_manager_caches(void)
+{
+	nat_entry_slab = f2fs_kmem_cache_create("f2fs_nat_entry",
+			sizeof(struct nat_entry));
+	if (!nat_entry_slab)
+		goto fail;
+
+	free_nid_slab = f2fs_kmem_cache_create("f2fs_free_nid",
+			sizeof(struct free_nid));
+	if (!free_nid_slab)
+		goto destroy_nat_entry;
+
+	nat_entry_set_slab = f2fs_kmem_cache_create("f2fs_nat_entry_set",
+			sizeof(struct nat_entry_set));
+	if (!nat_entry_set_slab)
+		goto destroy_free_nid;
+
+	fsync_node_entry_slab = f2fs_kmem_cache_create("f2fs_fsync_node_entry",
+			sizeof(struct fsync_node_entry));
+	if (!fsync_node_entry_slab)
+		goto destroy_nat_entry_set;
+	return 0;
+
+destroy_nat_entry_set:
+	kmem_cache_destroy(nat_entry_set_slab);
+destroy_free_nid:
+	kmem_cache_destroy(free_nid_slab);
+destroy_nat_entry:
+	kmem_cache_destroy(nat_entry_slab);
+fail:
+	return -ENOMEM;
+}
+
+void f2fs_destroy_node_manager_caches(void)
+{
+	kmem_cache_destroy(fsync_node_entry_slab);
+	kmem_cache_destroy(nat_entry_set_slab);
+	kmem_cache_destroy(free_nid_slab);
+	kmem_cache_destroy(nat_entry_slab);
+}