Merge tag 'for-f2fs-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs

Pull f2fs updates from Jaegeuk Kim:
 "New features:
   - in-memory extent_cache
   - fs_shutdown to test power-off-recovery
   - use inline_data to store symlink path
   - show f2fs as a non-misc filesystem

  Major fixes:
   - avoid CPU stalls on sync_dirty_dir_inodes
   - fix some power-off-recovery procedure
   - fix handling of broken symlink correctly
   - fix missing dot and dotdot made by sudden power cuts
   - handle wrong data index during roll-forward recovery
   - preallocate data blocks for direct_io

  ... and a bunch of minor bug fixes and cleanups"

* tag 'for-f2fs-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (71 commits)
  f2fs: pass checkpoint reason on roll-forward recovery
  f2fs: avoid abnormal behavior on broken symlink
  f2fs: flush symlink path to avoid broken symlink after POR
  f2fs: change 0 to false for bool type
  f2fs: do not recover wrong data index
  f2fs: do not increase link count during recovery
  f2fs: assign parent's i_mode for empty dir
  f2fs: add F2FS_INLINE_DOTS to recover missing dot dentries
  f2fs: fix mismatching lock and unlock pages for roll-forward recovery
  f2fs: fix sparse warnings
  f2fs: limit b_size of mapped bh in f2fs_map_bh
  f2fs: persist system.advise into on-disk inode
  f2fs: avoid NULL pointer dereference in f2fs_xattr_advise_get
  f2fs: preallocate fallocated blocks for direct IO
  f2fs: enable inline data by default
  f2fs: preserve extent info for extent cache
  f2fs: initialize extent tree with on-disk extent info of inode
  f2fs: introduce __{find,grab}_extent_tree
  f2fs: split set_data_blkaddr from f2fs_update_extent_cache
  f2fs: enable fast symlink by utilizing inline data
  ...

19 files changed, 1229 insertions, 260 deletions

diff --git a/fs/f2fs/Kconfig b/fs/f2fs/Kconfig
index 94e2d2f..05f0f66 100644
--- a/fs/f2fs/Kconfig
+++ b/fs/f2fs/Kconfig
@@ -1,5 +1,5 @@
 config F2FS_FS
-	tristate "F2FS filesystem support (EXPERIMENTAL)"
+	tristate "F2FS filesystem support"
 	depends on BLOCK
 	help
 	  F2FS is based on Log-structured File System (LFS), which supports
diff --git a/fs/f2fs/acl.c b/fs/f2fs/acl.c
index 7422027..4320ffa 100644
--- a/fs/f2fs/acl.c
+++ b/fs/f2fs/acl.c
@@ -351,13 +351,11 @@ static int f2fs_acl_create(struct inode *dir, umode_t *mode,
 
 	*acl = f2fs_acl_clone(p, GFP_NOFS);
 	if (!*acl)
-		return -ENOMEM;
+		goto no_mem;
 
 	ret = f2fs_acl_create_masq(*acl, mode);
-	if (ret < 0) {
-		posix_acl_release(*acl);
-		return -ENOMEM;
-	}
+	if (ret < 0)
+		goto no_mem_clone;
 
 	if (ret == 0) {
 		posix_acl_release(*acl);
@@ -378,6 +376,12 @@ no_acl:
 	*default_acl = NULL;
 	*acl = NULL;
 	return 0;
+
+no_mem_clone:
+	posix_acl_release(*acl);
+no_mem:
+	posix_acl_release(p);
+	return -ENOMEM;
 }
 
 int f2fs_init_acl(struct inode *inode, struct inode *dir, struct page *ipage,
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 7f794b7..a5e17a2 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -276,7 +276,7 @@ continue_unlock:
 			if (!clear_page_dirty_for_io(page))
 				goto continue_unlock;
 
-			if (f2fs_write_meta_page(page, &wbc)) {
+			if (mapping->a_ops->writepage(page, &wbc)) {
 				unlock_page(page);
 				break;
 			}
@@ -464,20 +464,19 @@ static void recover_orphan_inode(struct f2fs_sb_info *sbi, nid_t ino)
 
 void recover_orphan_inodes(struct f2fs_sb_info *sbi)
 {
-	block_t start_blk, orphan_blkaddr, i, j;
+	block_t start_blk, orphan_blocks, i, j;
 
 	if (!is_set_ckpt_flags(F2FS_CKPT(sbi), CP_ORPHAN_PRESENT_FLAG))
 		return;
 
 	set_sbi_flag(sbi, SBI_POR_DOING);
 
-	start_blk = __start_cp_addr(sbi) + 1 +
-		le32_to_cpu(F2FS_RAW_SUPER(sbi)->cp_payload);
-	orphan_blkaddr = __start_sum_addr(sbi) - 1;
+	start_blk = __start_cp_addr(sbi) + 1 + __cp_payload(sbi);
+	orphan_blocks = __start_sum_addr(sbi) - 1 - __cp_payload(sbi);
 
-	ra_meta_pages(sbi, start_blk, orphan_blkaddr, META_CP);
+	ra_meta_pages(sbi, start_blk, orphan_blocks, META_CP);
 
-	for (i = 0; i < orphan_blkaddr; i++) {
+	for (i = 0; i < orphan_blocks; i++) {
 		struct page *page = get_meta_page(sbi, start_blk + i);
 		struct f2fs_orphan_block *orphan_blk;
 
@@ -615,7 +614,7 @@ int get_valid_checkpoint(struct f2fs_sb_info *sbi)
 	unsigned long blk_size = sbi->blocksize;
 	unsigned long long cp1_version = 0, cp2_version = 0;
 	unsigned long long cp_start_blk_no;
-	unsigned int cp_blks = 1 + le32_to_cpu(F2FS_RAW_SUPER(sbi)->cp_payload);
+	unsigned int cp_blks = 1 + __cp_payload(sbi);
 	block_t cp_blk_no;
 	int i;
 
@@ -796,6 +795,7 @@ retry:
 		 * wribacking dentry pages in the freeing inode.
 		 */
 		f2fs_submit_merged_bio(sbi, DATA, WRITE);
+		cond_resched();
 	}
 	goto retry;
 }
@@ -884,7 +884,7 @@ static void do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 	__u32 crc32 = 0;
 	void *kaddr;
 	int i;
-	int cp_payload_blks = le32_to_cpu(F2FS_RAW_SUPER(sbi)->cp_payload);
+	int cp_payload_blks = __cp_payload(sbi);
 
 	/*
 	 * This avoids to conduct wrong roll-forward operations and uses
@@ -1048,17 +1048,18 @@ void write_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
 	unsigned long long ckpt_ver;
 
-	trace_f2fs_write_checkpoint(sbi->sb, cpc->reason, "start block_ops");
-
 	mutex_lock(&sbi->cp_mutex);
 
 	if (!is_sbi_flag_set(sbi, SBI_IS_DIRTY) &&
-			cpc->reason != CP_DISCARD && cpc->reason != CP_UMOUNT)
+		(cpc->reason == CP_FASTBOOT || cpc->reason == CP_SYNC))
 		goto out;
 	if (unlikely(f2fs_cp_error(sbi)))
 		goto out;
 	if (f2fs_readonly(sbi->sb))
 		goto out;
+
+	trace_f2fs_write_checkpoint(sbi->sb, cpc->reason, "start block_ops");
+
 	if (block_operations(sbi))
 		goto out;
 
@@ -1085,6 +1086,10 @@ void write_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 
 	unblock_operations(sbi);
 	stat_inc_cp_count(sbi->stat_info);
+
+	if (cpc->reason == CP_RECOVERY)
+		f2fs_msg(sbi->sb, KERN_NOTICE,
+			"checkpoint: version = %llx", ckpt_ver);
 out:
 	mutex_unlock(&sbi->cp_mutex);
 	trace_f2fs_write_checkpoint(sbi->sb, cpc->reason, "finish checkpoint");
@@ -1103,14 +1108,9 @@ void init_ino_entry_info(struct f2fs_sb_info *sbi)
 		im->ino_num = 0;
 	}
 
-	/*
-	 * considering 512 blocks in a segment 8 blocks are needed for cp
-	 * and log segment summaries. Remaining blocks are used to keep
-	 * orphan entries with the limitation one reserved segment
-	 * for cp pack we can have max 1020*504 orphan entries
-	 */
 	sbi->max_orphans = (sbi->blocks_per_seg - F2FS_CP_PACKS -
-			NR_CURSEG_TYPE) * F2FS_ORPHANS_PER_BLOCK;
+			NR_CURSEG_TYPE - __cp_payload(sbi)) *
+				F2FS_ORPHANS_PER_BLOCK;
 }
 
 int __init create_checkpoint_caches(void)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 319eda5..b91b0e1 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -25,6 +25,9 @@
 #include "trace.h"
 #include <trace/events/f2fs.h>
 
+static struct kmem_cache *extent_tree_slab;
+static struct kmem_cache *extent_node_slab;
+
 static void f2fs_read_end_io(struct bio *bio, int err)
 {
 	struct bio_vec *bvec;
@@ -197,7 +200,7 @@ alloc_new:
  *  ->node_page
  *    update block addresses in the node page
  */
-static void __set_data_blkaddr(struct dnode_of_data *dn)
+void set_data_blkaddr(struct dnode_of_data *dn)
 {
 	struct f2fs_node *rn;
 	__le32 *addr_array;
@@ -226,7 +229,7 @@ int reserve_new_block(struct dnode_of_data *dn)
 	trace_f2fs_reserve_new_block(dn->inode, dn->nid, dn->ofs_in_node);
 
 	dn->data_blkaddr = NEW_ADDR;
-	__set_data_blkaddr(dn);
+	set_data_blkaddr(dn);
 	mark_inode_dirty(dn->inode);
 	sync_inode_page(dn);
 	return 0;
@@ -248,73 +251,62 @@ int f2fs_reserve_block(struct dnode_of_data *dn, pgoff_t index)
 	return err;
 }
 
-static int check_extent_cache(struct inode *inode, pgoff_t pgofs,
-					struct buffer_head *bh_result)
+static void f2fs_map_bh(struct super_block *sb, pgoff_t pgofs,
+			struct extent_info *ei, struct buffer_head *bh_result)
+{
+	unsigned int blkbits = sb->s_blocksize_bits;
+	size_t max_size = bh_result->b_size;
+	size_t mapped_size;
+
+	clear_buffer_new(bh_result);
+	map_bh(bh_result, sb, ei->blk + pgofs - ei->fofs);
+	mapped_size = (ei->fofs + ei->len - pgofs) << blkbits;
+	bh_result->b_size = min(max_size, mapped_size);
+}
+
+static bool lookup_extent_info(struct inode *inode, pgoff_t pgofs,
+							struct extent_info *ei)
 {
 	struct f2fs_inode_info *fi = F2FS_I(inode);
 	pgoff_t start_fofs, end_fofs;
 	block_t start_blkaddr;
 
-	if (is_inode_flag_set(fi, FI_NO_EXTENT))
-		return 0;
-
-	read_lock(&fi->ext.ext_lock);
+	read_lock(&fi->ext_lock);
 	if (fi->ext.len == 0) {
-		read_unlock(&fi->ext.ext_lock);
-		return 0;
+		read_unlock(&fi->ext_lock);
+		return false;
 	}
 
 	stat_inc_total_hit(inode->i_sb);
 
 	start_fofs = fi->ext.fofs;
 	end_fofs = fi->ext.fofs + fi->ext.len - 1;
-	start_blkaddr = fi->ext.blk_addr;
+	start_blkaddr = fi->ext.blk;
 
 	if (pgofs >= start_fofs && pgofs <= end_fofs) {
-		unsigned int blkbits = inode->i_sb->s_blocksize_bits;
-		size_t count;
-
-		set_buffer_new(bh_result);
-		map_bh(bh_result, inode->i_sb,
-				start_blkaddr + pgofs - start_fofs);
-		count = end_fofs - pgofs + 1;
-		if (count < (UINT_MAX >> blkbits))
-			bh_result->b_size = (count << blkbits);
-		else
-			bh_result->b_size = UINT_MAX;
-
+		*ei = fi->ext;
 		stat_inc_read_hit(inode->i_sb);
-		read_unlock(&fi->ext.ext_lock);
-		return 1;
+		read_unlock(&fi->ext_lock);
+		return true;
 	}
-	read_unlock(&fi->ext.ext_lock);
-	return 0;
+	read_unlock(&fi->ext_lock);
+	return false;
 }
 
-void update_extent_cache(struct dnode_of_data *dn)
+static bool update_extent_info(struct inode *inode, pgoff_t fofs,
+								block_t blkaddr)
 {
-	struct f2fs_inode_info *fi = F2FS_I(dn->inode);
-	pgoff_t fofs, start_fofs, end_fofs;
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	pgoff_t start_fofs, end_fofs;
 	block_t start_blkaddr, end_blkaddr;
 	int need_update = true;
 
-	f2fs_bug_on(F2FS_I_SB(dn->inode), dn->data_blkaddr == NEW_ADDR);
-
-	/* Update the page address in the parent node */
-	__set_data_blkaddr(dn);
-
-	if (is_inode_flag_set(fi, FI_NO_EXTENT))
-		return;
-
-	fofs = start_bidx_of_node(ofs_of_node(dn->node_page), fi) +
-							dn->ofs_in_node;
-
-	write_lock(&fi->ext.ext_lock);
+	write_lock(&fi->ext_lock);
 
 	start_fofs = fi->ext.fofs;
 	end_fofs = fi->ext.fofs + fi->ext.len - 1;
-	start_blkaddr = fi->ext.blk_addr;
-	end_blkaddr = fi->ext.blk_addr + fi->ext.len - 1;
+	start_blkaddr = fi->ext.blk;
+	end_blkaddr = fi->ext.blk + fi->ext.len - 1;
 
 	/* Drop and initialize the matched extent */
 	if (fi->ext.len == 1 && fofs == start_fofs)
@@ -322,24 +314,24 @@ void update_extent_cache(struct dnode_of_data *dn)
 
 	/* Initial extent */
 	if (fi->ext.len == 0) {
-		if (dn->data_blkaddr != NULL_ADDR) {
+		if (blkaddr != NULL_ADDR) {
 			fi->ext.fofs = fofs;
-			fi->ext.blk_addr = dn->data_blkaddr;
+			fi->ext.blk = blkaddr;
 			fi->ext.len = 1;
 		}
 		goto end_update;
 	}
 
 	/* Front merge */
-	if (fofs == start_fofs - 1 && dn->data_blkaddr == start_blkaddr - 1) {
+	if (fofs == start_fofs - 1 && blkaddr == start_blkaddr - 1) {
 		fi->ext.fofs--;
-		fi->ext.blk_addr--;
+		fi->ext.blk--;
 		fi->ext.len++;
 		goto end_update;
 	}
 
 	/* Back merge */
-	if (fofs == end_fofs + 1 && dn->data_blkaddr == end_blkaddr + 1) {
+	if (fofs == end_fofs + 1 && blkaddr == end_blkaddr + 1) {
 		fi->ext.len++;
 		goto end_update;
 	}
@@ -351,8 +343,7 @@ void update_extent_cache(struct dnode_of_data *dn)
 			fi->ext.len = fofs - start_fofs;
 		} else {
 			fi->ext.fofs = fofs + 1;
-			fi->ext.blk_addr = start_blkaddr +
-					fofs - start_fofs + 1;
+			fi->ext.blk = start_blkaddr + fofs - start_fofs + 1;
 			fi->ext.len -= fofs - start_fofs + 1;
 		}
 	} else {
@@ -366,27 +357,583 @@ void update_extent_cache(struct dnode_of_data *dn)
 		need_update = true;
 	}
 end_update:
-	write_unlock(&fi->ext.ext_lock);
-	if (need_update)
-		sync_inode_page(dn);
+	write_unlock(&fi->ext_lock);
+	return need_update;
+}
+
+static struct extent_node *__attach_extent_node(struct f2fs_sb_info *sbi,
+				struct extent_tree *et, struct extent_info *ei,
+				struct rb_node *parent, struct rb_node **p)
+{
+	struct extent_node *en;
+
+	en = kmem_cache_alloc(extent_node_slab, GFP_ATOMIC);
+	if (!en)
+		return NULL;
+
+	en->ei = *ei;
+	INIT_LIST_HEAD(&en->list);
+
+	rb_link_node(&en->rb_node, parent, p);
+	rb_insert_color(&en->rb_node, &et->root);
+	et->count++;
+	atomic_inc(&sbi->total_ext_node);
+	return en;
+}
+
+static void __detach_extent_node(struct f2fs_sb_info *sbi,
+				struct extent_tree *et, struct extent_node *en)
+{
+	rb_erase(&en->rb_node, &et->root);
+	et->count--;
+	atomic_dec(&sbi->total_ext_node);
+
+	if (et->cached_en == en)
+		et->cached_en = NULL;
+}
+
+static struct extent_tree *__find_extent_tree(struct f2fs_sb_info *sbi,
+							nid_t ino)
+{
+	struct extent_tree *et;
+
+	down_read(&sbi->extent_tree_lock);
+	et = radix_tree_lookup(&sbi->extent_tree_root, ino);
+	if (!et) {
+		up_read(&sbi->extent_tree_lock);
+		return NULL;
+	}
+	atomic_inc(&et->refcount);
+	up_read(&sbi->extent_tree_lock);
+
+	return et;
+}
+
+static struct extent_tree *__grab_extent_tree(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct extent_tree *et;
+	nid_t ino = inode->i_ino;
+
+	down_write(&sbi->extent_tree_lock);
+	et = radix_tree_lookup(&sbi->extent_tree_root, ino);
+	if (!et) {
+		et = f2fs_kmem_cache_alloc(extent_tree_slab, GFP_NOFS);
+		f2fs_radix_tree_insert(&sbi->extent_tree_root, ino, et);
+		memset(et, 0, sizeof(struct extent_tree));
+		et->ino = ino;
+		et->root = RB_ROOT;
+		et->cached_en = NULL;
+		rwlock_init(&et->lock);
+		atomic_set(&et->refcount, 0);
+		et->count = 0;
+		sbi->total_ext_tree++;
+	}
+	atomic_inc(&et->refcount);
+	up_write(&sbi->extent_tree_lock);
+
+	return et;
+}
+
+static struct extent_node *__lookup_extent_tree(struct extent_tree *et,
+							unsigned int fofs)
+{
+	struct rb_node *node = et->root.rb_node;
+	struct extent_node *en;
+
+	if (et->cached_en) {
+		struct extent_info *cei = &et->cached_en->ei;
+
+		if (cei->fofs <= fofs && cei->fofs + cei->len > fofs)
+			return et->cached_en;
+	}
+
+	while (node) {
+		en = rb_entry(node, struct extent_node, rb_node);
+
+		if (fofs < en->ei.fofs) {
+			node = node->rb_left;
+		} else if (fofs >= en->ei.fofs + en->ei.len) {
+			node = node->rb_right;
+		} else {
+			et->cached_en = en;
+			return en;
+		}
+	}
+	return NULL;
+}
+
+static struct extent_node *__try_back_merge(struct f2fs_sb_info *sbi,
+				struct extent_tree *et, struct extent_node *en)
+{
+	struct extent_node *prev;
+	struct rb_node *node;
+
+	node = rb_prev(&en->rb_node);
+	if (!node)
+		return NULL;
+
+	prev = rb_entry(node, struct extent_node, rb_node);
+	if (__is_back_mergeable(&en->ei, &prev->ei)) {
+		en->ei.fofs = prev->ei.fofs;
+		en->ei.blk = prev->ei.blk;
+		en->ei.len += prev->ei.len;
+		__detach_extent_node(sbi, et, prev);
+		return prev;
+	}
+	return NULL;
+}
+
+static struct extent_node *__try_front_merge(struct f2fs_sb_info *sbi,
+				struct extent_tree *et, struct extent_node *en)
+{
+	struct extent_node *next;
+	struct rb_node *node;
+
+	node = rb_next(&en->rb_node);
+	if (!node)
+		return NULL;
+
+	next = rb_entry(node, struct extent_node, rb_node);
+	if (__is_front_mergeable(&en->ei, &next->ei)) {
+		en->ei.len += next->ei.len;
+		__detach_extent_node(sbi, et, next);
+		return next;
+	}
+	return NULL;
+}
+
+static struct extent_node *__insert_extent_tree(struct f2fs_sb_info *sbi,
+				struct extent_tree *et, struct extent_info *ei,
+				struct extent_node **den)
+{
+	struct rb_node **p = &et->root.rb_node;
+	struct rb_node *parent = NULL;
+	struct extent_node *en;
+
+	while (*p) {
+		parent = *p;
+		en = rb_entry(parent, struct extent_node, rb_node);
+
+		if (ei->fofs < en->ei.fofs) {
+			if (__is_front_mergeable(ei, &en->ei)) {
+				f2fs_bug_on(sbi, !den);
+				en->ei.fofs = ei->fofs;
+				en->ei.blk = ei->blk;
+				en->ei.len += ei->len;
+				*den = __try_back_merge(sbi, et, en);
+				return en;
+			}
+			p = &(*p)->rb_left;
+		} else if (ei->fofs >= en->ei.fofs + en->ei.len) {
+			if (__is_back_mergeable(ei, &en->ei)) {
+				f2fs_bug_on(sbi, !den);
+				en->ei.len += ei->len;
+				*den = __try_front_merge(sbi, et, en);
+				return en;
+			}
+			p = &(*p)->rb_right;
+		} else {
+			f2fs_bug_on(sbi, 1);
+		}
+	}
+
+	return __attach_extent_node(sbi, et, ei, parent, p);
+}
+
+static unsigned int __free_extent_tree(struct f2fs_sb_info *sbi,
+					struct extent_tree *et, bool free_all)
+{
+	struct rb_node *node, *next;
+	struct extent_node *en;
+	unsigned int count = et->count;
+
+	node = rb_first(&et->root);
+	while (node) {
+		next = rb_next(node);
+		en = rb_entry(node, struct extent_node, rb_node);
+
+		if (free_all) {
+			spin_lock(&sbi->extent_lock);
+			if (!list_empty(&en->list))
+				list_del_init(&en->list);
+			spin_unlock(&sbi->extent_lock);
+		}
+
+		if (free_all || list_empty(&en->list)) {
+			__detach_extent_node(sbi, et, en);
+			kmem_cache_free(extent_node_slab, en);
+		}
+		node = next;
+	}
+
+	return count - et->count;
+}
+
+static void f2fs_init_extent_tree(struct inode *inode,
+						struct f2fs_extent *i_ext)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct extent_tree *et;
+	struct extent_node *en;
+	struct extent_info ei;
+
+	if (le32_to_cpu(i_ext->len) < F2FS_MIN_EXTENT_LEN)
+		return;
+
+	et = __grab_extent_tree(inode);
+
+	write_lock(&et->lock);
+	if (et->count)
+		goto out;
+
+	set_extent_info(&ei, le32_to_cpu(i_ext->fofs),
+		le32_to_cpu(i_ext->blk), le32_to_cpu(i_ext->len));
+
+	en = __insert_extent_tree(sbi, et, &ei, NULL);
+	if (en) {
+		et->cached_en = en;
+
+		spin_lock(&sbi->extent_lock);
+		list_add_tail(&en->list, &sbi->extent_list);
+		spin_unlock(&sbi->extent_lock);
+	}
+out:
+	write_unlock(&et->lock);
+	atomic_dec(&et->refcount);
+}
+
+static bool f2fs_lookup_extent_tree(struct inode *inode, pgoff_t pgofs,
+							struct extent_info *ei)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct extent_tree *et;
+	struct extent_node *en;
+
+	trace_f2fs_lookup_extent_tree_start(inode, pgofs);
+
+	et = __find_extent_tree(sbi, inode->i_ino);
+	if (!et)
+		return false;
+
+	read_lock(&et->lock);
+	en = __lookup_extent_tree(et, pgofs);
+	if (en) {
+		*ei = en->ei;
+		spin_lock(&sbi->extent_lock);
+		if (!list_empty(&en->list))
+			list_move_tail(&en->list, &sbi->extent_list);
+		spin_unlock(&sbi->extent_lock);
+		stat_inc_read_hit(sbi->sb);
+	}
+	stat_inc_total_hit(sbi->sb);
+	read_unlock(&et->lock);
+
+	trace_f2fs_lookup_extent_tree_end(inode, pgofs, en);
+
+	atomic_dec(&et->refcount);
+	return en ? true : false;
+}
+
+static void f2fs_update_extent_tree(struct inode *inode, pgoff_t fofs,
+							block_t blkaddr)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct extent_tree *et;
+	struct extent_node *en = NULL, *en1 = NULL, *en2 = NULL, *en3 = NULL;
+	struct extent_node *den = NULL;
+	struct extent_info ei, dei;
+	unsigned int endofs;
+
+	trace_f2fs_update_extent_tree(inode, fofs, blkaddr);
+
+	et = __grab_extent_tree(inode);
+
+	write_lock(&et->lock);
+
+	/* 1. lookup and remove existing extent info in cache */
+	en = __lookup_extent_tree(et, fofs);
+	if (!en)
+		goto update_extent;
+
+	dei = en->ei;
+	__detach_extent_node(sbi, et, en);
+
+	/* 2. if extent can be split more, split and insert the left part */
+	if (dei.len > 1) {
+		/*  insert left part of split extent into cache */
+		if (fofs - dei.fofs >= F2FS_MIN_EXTENT_LEN) {
+			set_extent_info(&ei, dei.fofs, dei.blk,
+							fofs - dei.fofs);
+			en1 = __insert_extent_tree(sbi, et, &ei, NULL);
+		}
+
+		/* insert right part of split extent into cache */
+		endofs = dei.fofs + dei.len - 1;
+		if (endofs - fofs >= F2FS_MIN_EXTENT_LEN) {
+			set_extent_info(&ei, fofs + 1,
+				fofs - dei.fofs + dei.blk, endofs - fofs);
+			en2 = __insert_extent_tree(sbi, et, &ei, NULL);
+		}
+	}
+
+update_extent:
+	/* 3. update extent in extent cache */
+	if (blkaddr) {
+		set_extent_info(&ei, fofs, blkaddr, 1);
+		en3 = __insert_extent_tree(sbi, et, &ei, &den);
+	}
+
+	/* 4. update in global extent list */
+	spin_lock(&sbi->extent_lock);
+	if (en && !list_empty(&en->list))
+		list_del(&en->list);
+	/*
+	 * en1 and en2 split from en, they will become more and more smaller
+	 * fragments after splitting several times. So if the length is smaller
+	 * than F2FS_MIN_EXTENT_LEN, we will not add them into extent tree.
+	 */
+	if (en1)
+		list_add_tail(&en1->list, &sbi->extent_list);
+	if (en2)
+		list_add_tail(&en2->list, &sbi->extent_list);
+	if (en3) {
+		if (list_empty(&en3->list))
+			list_add_tail(&en3->list, &sbi->extent_list);
+		else
+			list_move_tail(&en3->list, &sbi->extent_list);
+	}
+	if (den && !list_empty(&den->list))
+		list_del(&den->list);
+	spin_unlock(&sbi->extent_lock);
+
+	/* 5. release extent node */
+	if (en)
+		kmem_cache_free(extent_node_slab, en);
+	if (den)
+		kmem_cache_free(extent_node_slab, den);
+
+	write_unlock(&et->lock);
+	atomic_dec(&et->refcount);
+}
+
+void f2fs_preserve_extent_tree(struct inode *inode)
+{
+	struct extent_tree *et;
+	struct extent_info *ext = &F2FS_I(inode)->ext;
+	bool sync = false;
+
+	if (!test_opt(F2FS_I_SB(inode), EXTENT_CACHE))
+		return;
+
+	et = __find_extent_tree(F2FS_I_SB(inode), inode->i_ino);
+	if (!et) {
+		if (ext->len) {
+			ext->len = 0;
+			update_inode_page(inode);
+		}
+		return;
+	}
+
+	read_lock(&et->lock);
+	if (et->count) {
+		struct extent_node *en;
+
+		if (et->cached_en) {
+			en = et->cached_en;
+		} else {
+			struct rb_node *node = rb_first(&et->root);
+
+			if (!node)
+				node = rb_last(&et->root);
+			en = rb_entry(node, struct extent_node, rb_node);
+		}
+
+		if (__is_extent_same(ext, &en->ei))
+			goto out;
+
+		*ext = en->ei;
+		sync = true;
+	} else if (ext->len) {
+		ext->len = 0;
+		sync = true;
+	}
+out:
+	read_unlock(&et->lock);
+	atomic_dec(&et->refcount);
+
+	if (sync)
+		update_inode_page(inode);
+}
+
+void f2fs_shrink_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink)
+{
+	struct extent_tree *treevec[EXT_TREE_VEC_SIZE];
+	struct extent_node *en, *tmp;
+	unsigned long ino = F2FS_ROOT_INO(sbi);
+	struct radix_tree_iter iter;
+	void **slot;
+	unsigned int found;
+	unsigned int node_cnt = 0, tree_cnt = 0;
+
+	if (!test_opt(sbi, EXTENT_CACHE))
+		return;
+
+	if (available_free_memory(sbi, EXTENT_CACHE))
+		return;
+
+	spin_lock(&sbi->extent_lock);
+	list_for_each_entry_safe(en, tmp, &sbi->extent_list, list) {
+		if (!nr_shrink--)
+			break;
+		list_del_init(&en->list);
+	}
+	spin_unlock(&sbi->extent_lock);
+
+	down_read(&sbi->extent_tree_lock);
+	while ((found = radix_tree_gang_lookup(&sbi->extent_tree_root,
+				(void **)treevec, ino, EXT_TREE_VEC_SIZE))) {
+		unsigned i;
+
+		ino = treevec[found - 1]->ino + 1;
+		for (i = 0; i < found; i++) {
+			struct extent_tree *et = treevec[i];
+
+			atomic_inc(&et->refcount);
+			write_lock(&et->lock);
+			node_cnt += __free_extent_tree(sbi, et, false);
+			write_unlock(&et->lock);
+			atomic_dec(&et->refcount);
+		}
+	}
+	up_read(&sbi->extent_tree_lock);
+
+	down_write(&sbi->extent_tree_lock);
+	radix_tree_for_each_slot(slot, &sbi->extent_tree_root, &iter,
+							F2FS_ROOT_INO(sbi)) {
+		struct extent_tree *et = (struct extent_tree *)*slot;
+
+		if (!atomic_read(&et->refcount) && !et->count) {
+			radix_tree_delete(&sbi->extent_tree_root, et->ino);
+			kmem_cache_free(extent_tree_slab, et);
+			sbi->total_ext_tree--;
+			tree_cnt++;
+		}
+	}
+	up_write(&sbi->extent_tree_lock);
+
+	trace_f2fs_shrink_extent_tree(sbi, node_cnt, tree_cnt);
+}
+
+void f2fs_destroy_extent_tree(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct extent_tree *et;
+	unsigned int node_cnt = 0;
+
+	if (!test_opt(sbi, EXTENT_CACHE))
+		return;
+
+	et = __find_extent_tree(sbi, inode->i_ino);
+	if (!et)
+		goto out;
+
+	/* free all extent info belong to this extent tree */
+	write_lock(&et->lock);
+	node_cnt = __free_extent_tree(sbi, et, true);
+	write_unlock(&et->lock);
+
+	atomic_dec(&et->refcount);
+
+	/* try to find and delete extent tree entry in radix tree */
+	down_write(&sbi->extent_tree_lock);
+	et = radix_tree_lookup(&sbi->extent_tree_root, inode->i_ino);
+	if (!et) {
+		up_write(&sbi->extent_tree_lock);
+		goto out;
+	}
+	f2fs_bug_on(sbi, atomic_read(&et->refcount) || et->count);
+	radix_tree_delete(&sbi->extent_tree_root, inode->i_ino);
+	kmem_cache_free(extent_tree_slab, et);
+	sbi->total_ext_tree--;
+	up_write(&sbi->extent_tree_lock);
+out:
+	trace_f2fs_destroy_extent_tree(inode, node_cnt);
 	return;
 }
 
+void f2fs_init_extent_cache(struct inode *inode, struct f2fs_extent *i_ext)
+{
+	if (test_opt(F2FS_I_SB(inode), EXTENT_CACHE))
+		f2fs_init_extent_tree(inode, i_ext);
+
+	write_lock(&F2FS_I(inode)->ext_lock);
+	get_extent_info(&F2FS_I(inode)->ext, *i_ext);
+	write_unlock(&F2FS_I(inode)->ext_lock);
+}
+
+static bool f2fs_lookup_extent_cache(struct inode *inode, pgoff_t pgofs,
+							struct extent_info *ei)
+{
+	if (is_inode_flag_set(F2FS_I(inode), FI_NO_EXTENT))
+		return false;
+
+	if (test_opt(F2FS_I_SB(inode), EXTENT_CACHE))
+		return f2fs_lookup_extent_tree(inode, pgofs, ei);
+
+	return lookup_extent_info(inode, pgofs, ei);
+}
+
+void f2fs_update_extent_cache(struct dnode_of_data *dn)
+{
+	struct f2fs_inode_info *fi = F2FS_I(dn->inode);
+	pgoff_t fofs;
+
+	f2fs_bug_on(F2FS_I_SB(dn->inode), dn->data_blkaddr == NEW_ADDR);
+
+	if (is_inode_flag_set(fi, FI_NO_EXTENT))
+		return;
+
+	fofs = start_bidx_of_node(ofs_of_node(dn->node_page), fi) +
+							dn->ofs_in_node;
+
+	if (test_opt(F2FS_I_SB(dn->inode), EXTENT_CACHE))
+		return f2fs_update_extent_tree(dn->inode, fofs,
+							dn->data_blkaddr);
+
+	if (update_extent_info(dn->inode, fofs, dn->data_blkaddr))
+		sync_inode_page(dn);
+}
+
 struct page *find_data_page(struct inode *inode, pgoff_t index, bool sync)
 {
 	struct address_space *mapping = inode->i_mapping;
 	struct dnode_of_data dn;
 	struct page *page;
+	struct extent_info ei;
 	int err;
 	struct f2fs_io_info fio = {
 		.type = DATA,
 		.rw = sync ? READ_SYNC : READA,
 	};
 
+	/*
+	 * If sync is false, it needs to check its block allocation.
+	 * This is need and triggered by two flows:
+	 *   gc and truncate_partial_data_page.
+	 */
+	if (!sync)
+		goto search;
+
 	page = find_get_page(mapping, index);
 	if (page && PageUptodate(page))
 		return page;
 	f2fs_put_page(page, 0);
+search:
+	if (f2fs_lookup_extent_cache(inode, index, &ei)) {
+		dn.data_blkaddr = ei.blk + index - ei.fofs;
+		goto got_it;
+	}
 
 	set_new_dnode(&dn, inode, NULL, NULL, 0);
 	err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
@@ -401,6 +948,7 @@ struct page *find_data_page(struct inode *inode, pgoff_t index, bool sync)
 	if (unlikely(dn.data_blkaddr == NEW_ADDR))
 		return ERR_PTR(-EINVAL);
 
+got_it:
 	page = grab_cache_page(mapping, index);
 	if (!page)
 		return ERR_PTR(-ENOMEM);
@@ -435,6 +983,7 @@ struct page *get_lock_data_page(struct inode *inode, pgoff_t index)
 	struct address_space *mapping = inode->i_mapping;
 	struct dnode_of_data dn;
 	struct page *page;
+	struct extent_info ei;
 	int err;
 	struct f2fs_io_info fio = {
 		.type = DATA,
@@ -445,6 +994,11 @@ repeat:
 	if (!page)
 		return ERR_PTR(-ENOMEM);
 
+	if (f2fs_lookup_extent_cache(inode, index, &ei)) {
+		dn.data_blkaddr = ei.blk + index - ei.fofs;
+		goto got_it;
+	}
+
 	set_new_dnode(&dn, inode, NULL, NULL, 0);
 	err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
 	if (err) {
@@ -458,6 +1012,7 @@ repeat:
 		return ERR_PTR(-ENOENT);
 	}
 
+got_it:
 	if (PageUptodate(page))
 		return page;
 
@@ -569,19 +1124,26 @@ static int __allocate_data_block(struct dnode_of_data *dn)
 
 	if (unlikely(is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC)))
 		return -EPERM;
+
+	dn->data_blkaddr = datablock_addr(dn->node_page, dn->ofs_in_node);
+	if (dn->data_blkaddr == NEW_ADDR)
+		goto alloc;
+
 	if (unlikely(!inc_valid_block_count(sbi, dn->inode, 1)))
 		return -ENOSPC;
 
+alloc:
 	get_node_info(sbi, dn->nid, &ni);
 	set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version);
 
 	if (dn->ofs_in_node == 0 && dn->inode_page == dn->node_page)
 		seg = CURSEG_DIRECT_IO;
 
-	allocate_data_block(sbi, NULL, NULL_ADDR, &dn->data_blkaddr, &sum, seg);
+	allocate_data_block(sbi, NULL, dn->data_blkaddr, &dn->data_blkaddr,
+								&sum, seg);
 
 	/* direct IO doesn't use extent cache to maximize the performance */
-	__set_data_blkaddr(dn);
+	set_data_blkaddr(dn);
 
 	/* update i_size */
 	fofs = start_bidx_of_node(ofs_of_node(dn->node_page), fi) +
@@ -615,7 +1177,10 @@ static void __allocate_data_blocks(struct inode *inode, loff_t offset,
 		end_offset = ADDRS_PER_PAGE(dn.node_page, F2FS_I(inode));
 
 		while (dn.ofs_in_node < end_offset && len) {
-			if (dn.data_blkaddr == NULL_ADDR) {
+			block_t blkaddr;
+
+			blkaddr = datablock_addr(dn.node_page, dn.ofs_in_node);
+			if (blkaddr == NULL_ADDR || blkaddr == NEW_ADDR) {
 				if (__allocate_data_block(&dn))
 					goto sync_out;
 				allocated = true;
@@ -659,13 +1224,16 @@ static int __get_data_block(struct inode *inode, sector_t iblock,
 	int mode = create ? ALLOC_NODE : LOOKUP_NODE_RA;
 	pgoff_t pgofs, end_offset;
 	int err = 0, ofs = 1;
+	struct extent_info ei;
 	bool allocated = false;
 
 	/* Get the page offset from the block offset(iblock) */
 	pgofs =	(pgoff_t)(iblock >> (PAGE_CACHE_SHIFT - blkbits));
 
-	if (check_extent_cache(inode, pgofs, bh_result))
+	if (f2fs_lookup_extent_cache(inode, pgofs, &ei)) {
+		f2fs_map_bh(inode->i_sb, pgofs, &ei, bh_result);
 		goto out;
+	}
 
 	if (create)
 		f2fs_lock_op(F2FS_I_SB(inode));
@@ -682,7 +1250,7 @@ static int __get_data_block(struct inode *inode, sector_t iblock,
 		goto put_out;
 
 	if (dn.data_blkaddr != NULL_ADDR) {
-		set_buffer_new(bh_result);
+		clear_buffer_new(bh_result);
 		map_bh(bh_result, inode->i_sb, dn.data_blkaddr);
 	} else if (create) {
 		err = __allocate_data_block(&dn);
@@ -727,6 +1295,7 @@ get_next:
 			if (err)
 				goto sync_out;
 			allocated = true;
+			set_buffer_new(bh_result);
 			blkaddr = dn.data_blkaddr;
 		}
 		/* Give more consecutive addresses for the readahead */
@@ -813,8 +1382,10 @@ int do_write_data_page(struct page *page, struct f2fs_io_info *fio)
 	fio->blk_addr = dn.data_blkaddr;
 
 	/* This page is already truncated */
-	if (fio->blk_addr == NULL_ADDR)
+	if (fio->blk_addr == NULL_ADDR) {
+		ClearPageUptodate(page);
 		goto out_writepage;
+	}
 
 	set_page_writeback(page);
 
@@ -827,10 +1398,15 @@ int do_write_data_page(struct page *page, struct f2fs_io_info *fio)
 			need_inplace_update(inode))) {
 		rewrite_data_page(page, fio);
 		set_inode_flag(F2FS_I(inode), FI_UPDATE_WRITE);
+		trace_f2fs_do_write_data_page(page, IPU);
 	} else {
 		write_data_page(page, &dn, fio);
-		update_extent_cache(&dn);
+		set_data_blkaddr(&dn);
+		f2fs_update_extent_cache(&dn);
+		trace_f2fs_do_write_data_page(page, OPU);
 		set_inode_flag(F2FS_I(inode), FI_APPEND_WRITE);
+		if (page->index == 0)
+			set_inode_flag(F2FS_I(inode), FI_FIRST_BLOCK_WRITTEN);
 	}
 out_writepage:
 	f2fs_put_dnode(&dn);
@@ -909,6 +1485,8 @@ done:
 	clear_cold_data(page);
 out:
 	inode_dec_dirty_pages(inode);
+	if (err)
+		ClearPageUptodate(page);
 	unlock_page(page);
 	if (need_balance_fs)
 		f2fs_balance_fs(sbi);
@@ -935,7 +1513,6 @@ static int f2fs_write_data_pages(struct address_space *mapping,
 {
 	struct inode *inode = mapping->host;
 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
-	bool locked = false;
 	int ret;
 	long diff;
 
@@ -950,15 +1527,13 @@ static int f2fs_write_data_pages(struct address_space *mapping,
 			available_free_memory(sbi, DIRTY_DENTS))
 		goto skip_write;
 
+	/* during POR, we don't need to trigger writepage at all. */
+	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
+		goto skip_write;
+
 	diff = nr_pages_to_write(sbi, DATA, wbc);
 
-	if (!S_ISDIR(inode->i_mode)) {
-		mutex_lock(&sbi->writepages);
-		locked = true;
-	}
 	ret = write_cache_pages(mapping, wbc, __f2fs_writepage, mapping);
-	if (locked)
-		mutex_unlock(&sbi->writepages);
 
 	f2fs_submit_merged_bio(sbi, DATA, WRITE);
 
@@ -1236,6 +1811,37 @@ static sector_t f2fs_bmap(struct address_space *mapping, sector_t block)
 	return generic_block_bmap(mapping, block, get_data_block);
 }
 
+void init_extent_cache_info(struct f2fs_sb_info *sbi)
+{
+	INIT_RADIX_TREE(&sbi->extent_tree_root, GFP_NOIO);
+	init_rwsem(&sbi->extent_tree_lock);
+	INIT_LIST_HEAD(&sbi->extent_list);
+	spin_lock_init(&sbi->extent_lock);
+	sbi->total_ext_tree = 0;
+	atomic_set(&sbi->total_ext_node, 0);
+}
+
+int __init create_extent_cache(void)
+{
+	extent_tree_slab = f2fs_kmem_cache_create("f2fs_extent_tree",
+			sizeof(struct extent_tree));
+	if (!extent_tree_slab)
+		return -ENOMEM;
+	extent_node_slab = f2fs_kmem_cache_create("f2fs_extent_node",
+			sizeof(struct extent_node));
+	if (!extent_node_slab) {
+		kmem_cache_destroy(extent_tree_slab);
+		return -ENOMEM;
+	}
+	return 0;
+}
+
+void destroy_extent_cache(void)
+{
+	kmem_cache_destroy(extent_node_slab);
+	kmem_cache_destroy(extent_tree_slab);
+}
+
 const struct address_space_operations f2fs_dblock_aops = {
 	.readpage	= f2fs_read_data_page,
 	.readpages	= f2fs_read_data_pages,
diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c
index e671373..f5388f3 100644
--- a/fs/f2fs/debug.c
+++ b/fs/f2fs/debug.c
@@ -35,6 +35,8 @@ static void update_general_status(struct f2fs_sb_info *sbi)
 	/* validation check of the segment numbers */
 	si->hit_ext = sbi->read_hit_ext;
 	si->total_ext = sbi->total_hit_ext;
+	si->ext_tree = sbi->total_ext_tree;
+	si->ext_node = atomic_read(&sbi->total_ext_node);
 	si->ndirty_node = get_pages(sbi, F2FS_DIRTY_NODES);
 	si->ndirty_dent = get_pages(sbi, F2FS_DIRTY_DENTS);
 	si->ndirty_dirs = sbi->n_dirty_dirs;
@@ -185,6 +187,9 @@ get_cache:
 	si->cache_mem += sbi->n_dirty_dirs * sizeof(struct inode_entry);
 	for (i = 0; i <= UPDATE_INO; i++)
 		si->cache_mem += sbi->im[i].ino_num * sizeof(struct ino_entry);
+	si->cache_mem += sbi->total_ext_tree * sizeof(struct extent_tree);
+	si->cache_mem += atomic_read(&sbi->total_ext_node) *
+						sizeof(struct extent_node);
 
 	si->page_mem = 0;
 	npages = NODE_MAPPING(sbi)->nrpages;
@@ -260,13 +265,20 @@ static int stat_show(struct seq_file *s, void *v)
 		seq_printf(s, "CP calls: %d\n", si->cp_count);
 		seq_printf(s, "GC calls: %d (BG: %d)\n",
 			   si->call_count, si->bg_gc);
-		seq_printf(s, "  - data segments : %d\n", si->data_segs);
-		seq_printf(s, "  - node segments : %d\n", si->node_segs);
-		seq_printf(s, "Try to move %d blocks\n", si->tot_blks);
-		seq_printf(s, "  - data blocks : %d\n", si->data_blks);
-		seq_printf(s, "  - node blocks : %d\n", si->node_blks);
+		seq_printf(s, "  - data segments : %d (%d)\n",
+				si->data_segs, si->bg_data_segs);
+		seq_printf(s, "  - node segments : %d (%d)\n",
+				si->node_segs, si->bg_node_segs);
+		seq_printf(s, "Try to move %d blocks (BG: %d)\n", si->tot_blks,
+				si->bg_data_blks + si->bg_node_blks);
+		seq_printf(s, "  - data blocks : %d (%d)\n", si->data_blks,
+				si->bg_data_blks);
+		seq_printf(s, "  - node blocks : %d (%d)\n", si->node_blks,
+				si->bg_node_blks);
 		seq_printf(s, "\nExtent Hit Ratio: %d / %d\n",
 			   si->hit_ext, si->total_ext);
+		seq_printf(s, "\nExtent Tree Count: %d\n", si->ext_tree);
+		seq_printf(s, "\nExtent Node Count: %d\n", si->ext_node);
 		seq_puts(s, "\nBalancing F2FS Async:\n");
 		seq_printf(s, "  - inmem: %4d, wb: %4d\n",
 			   si->inmem_pages, si->wb_pages);
diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index b74097a..3a3302a 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -59,9 +59,8 @@ static unsigned char f2fs_type_by_mode[S_IFMT >> S_SHIFT] = {
 	[S_IFLNK >> S_SHIFT]	= F2FS_FT_SYMLINK,
 };
 
-void set_de_type(struct f2fs_dir_entry *de, struct inode *inode)
+void set_de_type(struct f2fs_dir_entry *de, umode_t mode)
 {
-	umode_t mode = inode->i_mode;
 	de->file_type = f2fs_type_by_mode[(mode & S_IFMT) >> S_SHIFT];
 }
 
@@ -127,22 +126,19 @@ struct f2fs_dir_entry *find_target_dentry(struct qstr *name, int *max_slots,
 		*max_slots = 0;
 	while (bit_pos < d->max) {
 		if (!test_bit_le(bit_pos, d->bitmap)) {
-			if (bit_pos == 0)
-				max_len = 1;
-			else if (!test_bit_le(bit_pos - 1, d->bitmap))
-				max_len++;
 			bit_pos++;
+			max_len++;
 			continue;
 		}
+
 		de = &d->dentry[bit_pos];
 		if (early_match_name(name->len, namehash, de) &&
 			!memcmp(d->filename[bit_pos], name->name, name->len))
 			goto found;
 
-		if (max_slots && *max_slots >= 0 && max_len > *max_slots) {
+		if (max_slots && max_len > *max_slots)
 			*max_slots = max_len;
-			max_len = 0;
-		}
+		max_len = 0;
 
 		/* remain bug on condition */
 		if (unlikely(!de->name_len))
@@ -219,14 +215,14 @@ struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir,
 	unsigned int max_depth;
 	unsigned int level;
 
+	*res_page = NULL;
+
 	if (f2fs_has_inline_dentry(dir))
 		return find_in_inline_dir(dir, child, res_page);
 
 	if (npages == 0)
 		return NULL;
 
-	*res_page = NULL;
-
 	name_hash = f2fs_dentry_hash(child);
 	max_depth = F2FS_I(dir)->i_current_depth;
 
@@ -285,7 +281,7 @@ void f2fs_set_link(struct inode *dir, struct f2fs_dir_entry *de,
 	lock_page(page);
 	f2fs_wait_on_page_writeback(page, type);
 	de->ino = cpu_to_le32(inode->i_ino);
-	set_de_type(de, inode);
+	set_de_type(de, inode->i_mode);
 	f2fs_dentry_kunmap(dir, page);
 	set_page_dirty(page);
 	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
@@ -331,14 +327,14 @@ void do_make_empty_dir(struct inode *inode, struct inode *parent,
 	de->hash_code = 0;
 	de->ino = cpu_to_le32(inode->i_ino);
 	memcpy(d->filename[0], ".", 1);
-	set_de_type(de, inode);
+	set_de_type(de, inode->i_mode);
 
 	de = &d->dentry[1];
 	de->hash_code = 0;
 	de->name_len = cpu_to_le16(2);
 	de->ino = cpu_to_le32(parent->i_ino);
 	memcpy(d->filename[1], "..", 2);
-	set_de_type(de, inode);
+	set_de_type(de, parent->i_mode);
 
 	test_and_set_bit_le(0, (void *)d->bitmap);
 	test_and_set_bit_le(1, (void *)d->bitmap);
@@ -435,7 +431,7 @@ error:
 void update_parent_metadata(struct inode *dir, struct inode *inode,
 						unsigned int current_depth)
 {
-	if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
+	if (inode && is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
 		if (S_ISDIR(inode->i_mode)) {
 			inc_nlink(dir);
 			set_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
@@ -450,7 +446,7 @@ void update_parent_metadata(struct inode *dir, struct inode *inode,
 		set_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
 	}
 
-	if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK))
+	if (inode && is_inode_flag_set(F2FS_I(inode), FI_INC_LINK))
 		clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
 }
 
@@ -474,30 +470,47 @@ next:
 	goto next;
 }
 
+void f2fs_update_dentry(nid_t ino, umode_t mode, struct f2fs_dentry_ptr *d,
+				const struct qstr *name, f2fs_hash_t name_hash,
+				unsigned int bit_pos)
+{
+	struct f2fs_dir_entry *de;
+	int slots = GET_DENTRY_SLOTS(name->len);
+	int i;
+
+	de = &d->dentry[bit_pos];
+	de->hash_code = name_hash;
+	de->name_len = cpu_to_le16(name->len);
+	memcpy(d->filename[bit_pos], name->name, name->len);
+	de->ino = cpu_to_le32(ino);
+	set_de_type(de, mode);
+	for (i = 0; i < slots; i++)
+		test_and_set_bit_le(bit_pos + i, (void *)d->bitmap);
+}
+
 /*
  * Caller should grab and release a rwsem by calling f2fs_lock_op() and
  * f2fs_unlock_op().
  */
 int __f2fs_add_link(struct inode *dir, const struct qstr *name,
-						struct inode *inode)
+				struct inode *inode, nid_t ino, umode_t mode)
 {
 	unsigned int bit_pos;
 	unsigned int level;
 	unsigned int current_depth;
 	unsigned long bidx, block;
 	f2fs_hash_t dentry_hash;
-	struct f2fs_dir_entry *de;
 	unsigned int nbucket, nblock;
 	size_t namelen = name->len;
 	struct page *dentry_page = NULL;
 	struct f2fs_dentry_block *dentry_blk = NULL;
+	struct f2fs_dentry_ptr d;
 	int slots = GET_DENTRY_SLOTS(namelen);
-	struct page *page;
+	struct page *page = NULL;
 	int err = 0;
-	int i;
 
 	if (f2fs_has_inline_dentry(dir)) {
-		err = f2fs_add_inline_entry(dir, name, inode);
+		err = f2fs_add_inline_entry(dir, name, inode, ino, mode);
 		if (!err || err != -EAGAIN)
 			return err;
 		else
@@ -547,30 +560,31 @@ start:
 add_dentry:
 	f2fs_wait_on_page_writeback(dentry_page, DATA);
 
-	down_write(&F2FS_I(inode)->i_sem);
-	page = init_inode_metadata(inode, dir, name, NULL);
-	if (IS_ERR(page)) {
-		err = PTR_ERR(page);
-		goto fail;
+	if (inode) {
+		down_write(&F2FS_I(inode)->i_sem);
+		page = init_inode_metadata(inode, dir, name, NULL);
+		if (IS_ERR(page)) {
+			err = PTR_ERR(page);
+			goto fail;
+		}
 	}
-	de = &dentry_blk->dentry[bit_pos];
-	de->hash_code = dentry_hash;
-	de->name_len = cpu_to_le16(namelen);
-	memcpy(dentry_blk->filename[bit_pos], name->name, name->len);
-	de->ino = cpu_to_le32(inode->i_ino);
-	set_de_type(de, inode);
-	for (i = 0; i < slots; i++)
-		test_and_set_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
+
+	make_dentry_ptr(&d, (void *)dentry_blk, 1);
+	f2fs_update_dentry(ino, mode, &d, name, dentry_hash, bit_pos);
+
 	set_page_dirty(dentry_page);
 
-	/* we don't need to mark_inode_dirty now */
-	F2FS_I(inode)->i_pino = dir->i_ino;
-	update_inode(inode, page);
-	f2fs_put_page(page, 1);
+	if (inode) {
+		/* we don't need to mark_inode_dirty now */
+		F2FS_I(inode)->i_pino = dir->i_ino;
+		update_inode(inode, page);
+		f2fs_put_page(page, 1);
+	}
 
 	update_parent_metadata(dir, inode, current_depth);
 fail:
-	up_write(&F2FS_I(inode)->i_sem);
+	if (inode)
+		up_write(&F2FS_I(inode)->i_sem);
 
 	if (is_inode_flag_set(F2FS_I(dir), FI_UPDATE_DIR)) {
 		update_inode_page(dir);
@@ -669,6 +683,7 @@ void f2fs_delete_entry(struct f2fs_dir_entry *dentry, struct page *page,
 	if (bit_pos == NR_DENTRY_IN_BLOCK) {
 		truncate_hole(dir, page->index, page->index + 1);
 		clear_page_dirty_for_io(page);
+		ClearPagePrivate(page);
 		ClearPageUptodate(page);
 		inode_dec_dirty_pages(dir);
 	}
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 7fa3313..c06a25e 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -50,6 +50,7 @@
 #define F2FS_MOUNT_FLUSH_MERGE		0x00000400
 #define F2FS_MOUNT_NOBARRIER		0x00000800
 #define F2FS_MOUNT_FASTBOOT		0x00001000
+#define F2FS_MOUNT_EXTENT_CACHE		0x00002000
 
 #define clear_opt(sbi, option)	(sbi->mount_opt.opt &= ~F2FS_MOUNT_##option)
 #define set_opt(sbi, option)	(sbi->mount_opt.opt |= F2FS_MOUNT_##option)
@@ -102,6 +103,7 @@ enum {
 	CP_UMOUNT,
 	CP_FASTBOOT,
 	CP_SYNC,
+	CP_RECOVERY,
 	CP_DISCARD,
 };
 
@@ -216,6 +218,15 @@ static inline bool __has_cursum_space(struct f2fs_summary_block *sum, int size,
 #define F2FS_IOC_RELEASE_VOLATILE_WRITE	_IO(F2FS_IOCTL_MAGIC, 4)
 #define F2FS_IOC_ABORT_VOLATILE_WRITE	_IO(F2FS_IOCTL_MAGIC, 5)
 
+/*
+ * should be same as XFS_IOC_GOINGDOWN.
+ * Flags for going down operation used by FS_IOC_GOINGDOWN
+ */
+#define F2FS_IOC_SHUTDOWN	_IOR('X', 125, __u32)	/* Shutdown */
+#define F2FS_GOING_DOWN_FULLSYNC	0x0	/* going down with full sync */
+#define F2FS_GOING_DOWN_METASYNC	0x1	/* going down with metadata */
+#define F2FS_GOING_DOWN_NOSYNC		0x2	/* going down */
+
 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
 /*
  * ioctl commands in 32 bit emulation
@@ -273,14 +284,34 @@ enum {
 
 #define MAX_DIR_RA_PAGES	4	/* maximum ra pages of dir */
 
+/* vector size for gang look-up from extent cache that consists of radix tree */
+#define EXT_TREE_VEC_SIZE	64
+
 /* for in-memory extent cache entry */
-#define F2FS_MIN_EXTENT_LEN	16	/* minimum extent length */
+#define F2FS_MIN_EXTENT_LEN	64	/* minimum extent length */
+
+/* number of extent info in extent cache we try to shrink */
+#define EXTENT_CACHE_SHRINK_NUMBER	128
 
 struct extent_info {
-	rwlock_t ext_lock;	/* rwlock for consistency */
-	unsigned int fofs;	/* start offset in a file */
-	u32 blk_addr;		/* start block address of the extent */
-	unsigned int len;	/* length of the extent */
+	unsigned int fofs;		/* start offset in a file */
+	u32 blk;			/* start block address of the extent */
+	unsigned int len;		/* length of the extent */
+};
+
+struct extent_node {
+	struct rb_node rb_node;		/* rb node located in rb-tree */
+	struct list_head list;		/* node in global extent list of sbi */
+	struct extent_info ei;		/* extent info */
+};
+
+struct extent_tree {
+	nid_t ino;			/* inode number */
+	struct rb_root root;		/* root of extent info rb-tree */
+	struct extent_node *cached_en;	/* recently accessed extent node */
+	rwlock_t lock;			/* protect extent info rb-tree */
+	atomic_t refcount;		/* reference count of rb-tree */
+	unsigned int count;		/* # of extent node in rb-tree*/
 };
 
 /*
@@ -309,6 +340,7 @@ struct f2fs_inode_info {
 	nid_t i_xattr_nid;		/* node id that contains xattrs */
 	unsigned long long xattr_ver;	/* cp version of xattr modification */
 	struct extent_info ext;		/* in-memory extent cache entry */
+	rwlock_t ext_lock;		/* rwlock for single extent cache */
 	struct inode_entry *dirty_dir;	/* the pointer of dirty dir */
 
 	struct radix_tree_root inmem_root;	/* radix tree for inmem pages */
@@ -319,21 +351,51 @@ struct f2fs_inode_info {
 static inline void get_extent_info(struct extent_info *ext,
 					struct f2fs_extent i_ext)
 {
-	write_lock(&ext->ext_lock);
 	ext->fofs = le32_to_cpu(i_ext.fofs);
-	ext->blk_addr = le32_to_cpu(i_ext.blk_addr);
+	ext->blk = le32_to_cpu(i_ext.blk);
 	ext->len = le32_to_cpu(i_ext.len);
-	write_unlock(&ext->ext_lock);
 }
 
 static inline void set_raw_extent(struct extent_info *ext,
 					struct f2fs_extent *i_ext)
 {
-	read_lock(&ext->ext_lock);
 	i_ext->fofs = cpu_to_le32(ext->fofs);
-	i_ext->blk_addr = cpu_to_le32(ext->blk_addr);
+	i_ext->blk = cpu_to_le32(ext->blk);
 	i_ext->len = cpu_to_le32(ext->len);
-	read_unlock(&ext->ext_lock);
+}
+
+static inline void set_extent_info(struct extent_info *ei, unsigned int fofs,
+						u32 blk, unsigned int len)
+{
+	ei->fofs = fofs;
+	ei->blk = blk;
+	ei->len = len;
+}
+
+static inline bool __is_extent_same(struct extent_info *ei1,
+						struct extent_info *ei2)
+{
+	return (ei1->fofs == ei2->fofs && ei1->blk == ei2->blk &&
+						ei1->len == ei2->len);
+}
+
+static inline bool __is_extent_mergeable(struct extent_info *back,
+						struct extent_info *front)
+{
+	return (back->fofs + back->len == front->fofs &&
+			back->blk + back->len == front->blk);
+}
+
+static inline bool __is_back_mergeable(struct extent_info *cur,
+						struct extent_info *back)
+{
+	return __is_extent_mergeable(back, cur);
+}
+
+static inline bool __is_front_mergeable(struct extent_info *cur,
+						struct extent_info *front)
+{
+	return __is_extent_mergeable(cur, front);
 }
 
 struct f2fs_nm_info {
@@ -502,6 +564,10 @@ enum page_type {
 	META,
 	NR_PAGE_TYPE,
 	META_FLUSH,
+	INMEM,		/* the below types are used by tracepoints only. */
+	INMEM_DROP,
+	IPU,
+	OPU,
 };
 
 struct f2fs_io_info {
@@ -559,7 +625,6 @@ struct f2fs_sb_info {
 	struct mutex cp_mutex;			/* checkpoint procedure lock */
 	struct rw_semaphore cp_rwsem;		/* blocking FS operations */
 	struct rw_semaphore node_write;		/* locking node writes */
-	struct mutex writepages;		/* mutex for writepages() */
 	wait_queue_head_t cp_wait;
 
 	struct inode_management im[MAX_INO_ENTRY];      /* manage inode cache */
@@ -571,6 +636,14 @@ struct f2fs_sb_info {
 	struct list_head dir_inode_list;	/* dir inode list */
 	spinlock_t dir_inode_lock;		/* for dir inode list lock */
 
+	/* for extent tree cache */
+	struct radix_tree_root extent_tree_root;/* cache extent cache entries */
+	struct rw_semaphore extent_tree_lock;	/* locking extent radix tree */
+	struct list_head extent_list;		/* lru list for shrinker */
+	spinlock_t extent_lock;			/* locking extent lru list */
+	int total_ext_tree;			/* extent tree count */
+	atomic_t total_ext_node;		/* extent info count */
+
 	/* basic filesystem units */
 	unsigned int log_sectors_per_block;	/* log2 sectors per block */
 	unsigned int log_blocksize;		/* log2 block size */
@@ -920,12 +993,17 @@ static inline unsigned long __bitmap_size(struct f2fs_sb_info *sbi, int flag)
 	return 0;
 }
 
+static inline block_t __cp_payload(struct f2fs_sb_info *sbi)
+{
+	return le32_to_cpu(F2FS_RAW_SUPER(sbi)->cp_payload);
+}
+
 static inline void *__bitmap_ptr(struct f2fs_sb_info *sbi, int flag)
 {
 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
 	int offset;
 
-	if (le32_to_cpu(F2FS_RAW_SUPER(sbi)->cp_payload) > 0) {
+	if (__cp_payload(sbi) > 0) {
 		if (flag == NAT_BITMAP)
 			return &ckpt->sit_nat_version_bitmap;
 		else
@@ -1166,8 +1244,10 @@ enum {
 	FI_NEED_IPU,		/* used for ipu per file */
 	FI_ATOMIC_FILE,		/* indicate atomic file */
 	FI_VOLATILE_FILE,	/* indicate volatile file */
+	FI_FIRST_BLOCK_WRITTEN,	/* indicate #0 data block was written */
 	FI_DROP_CACHE,		/* drop dirty page cache */
 	FI_DATA_EXIST,		/* indicate data exists */
+	FI_INLINE_DOTS,		/* indicate inline dot dentries */
 };
 
 static inline void set_inode_flag(struct f2fs_inode_info *fi, int flag)
@@ -1204,6 +1284,8 @@ static inline void get_inline_info(struct f2fs_inode_info *fi,
 		set_inode_flag(fi, FI_INLINE_DENTRY);
 	if (ri->i_inline & F2FS_DATA_EXIST)
 		set_inode_flag(fi, FI_DATA_EXIST);
+	if (ri->i_inline & F2FS_INLINE_DOTS)
+		set_inode_flag(fi, FI_INLINE_DOTS);
 }
 
 static inline void set_raw_inline(struct f2fs_inode_info *fi,
@@ -1219,6 +1301,8 @@ static inline void set_raw_inline(struct f2fs_inode_info *fi,
 		ri->i_inline |= F2FS_INLINE_DENTRY;
 	if (is_inode_flag_set(fi, FI_DATA_EXIST))
 		ri->i_inline |= F2FS_DATA_EXIST;
+	if (is_inode_flag_set(fi, FI_INLINE_DOTS))
+		ri->i_inline |= F2FS_INLINE_DOTS;
 }
 
 static inline int f2fs_has_inline_xattr(struct inode *inode)
@@ -1264,6 +1348,11 @@ static inline int f2fs_exist_data(struct inode *inode)
 	return is_inode_flag_set(F2FS_I(inode), FI_DATA_EXIST);
 }
 
+static inline int f2fs_has_inline_dots(struct inode *inode)
+{
+	return is_inode_flag_set(F2FS_I(inode), FI_INLINE_DOTS);
+}
+
 static inline bool f2fs_is_atomic_file(struct inode *inode)
 {
 	return is_inode_flag_set(F2FS_I(inode), FI_ATOMIC_FILE);
@@ -1274,6 +1363,11 @@ static inline bool f2fs_is_volatile_file(struct inode *inode)
 	return is_inode_flag_set(F2FS_I(inode), FI_VOLATILE_FILE);
 }
 
+static inline bool f2fs_is_first_block_written(struct inode *inode)
+{
+	return is_inode_flag_set(F2FS_I(inode), FI_FIRST_BLOCK_WRITTEN);
+}
+
 static inline bool f2fs_is_drop_cache(struct inode *inode)
 {
 	return is_inode_flag_set(F2FS_I(inode), FI_DROP_CACHE);
@@ -1290,12 +1384,6 @@ static inline int f2fs_has_inline_dentry(struct inode *inode)
 	return is_inode_flag_set(F2FS_I(inode), FI_INLINE_DENTRY);
 }
 
-static inline void *inline_dentry_addr(struct page *page)
-{
-	struct f2fs_inode *ri = F2FS_INODE(page);
-	return (void *)&(ri->i_addr[1]);
-}
-
 static inline void f2fs_dentry_kunmap(struct inode *dir, struct page *page)
 {
 	if (!f2fs_has_inline_dentry(dir))
@@ -1363,7 +1451,7 @@ struct dentry *f2fs_get_parent(struct dentry *child);
  * dir.c
  */
 extern unsigned char f2fs_filetype_table[F2FS_FT_MAX];
-void set_de_type(struct f2fs_dir_entry *, struct inode *);
+void set_de_type(struct f2fs_dir_entry *, umode_t);
 struct f2fs_dir_entry *find_target_dentry(struct qstr *, int *,
 			struct f2fs_dentry_ptr *);
 bool f2fs_fill_dentries(struct dir_context *, struct f2fs_dentry_ptr *,
@@ -1382,7 +1470,10 @@ ino_t f2fs_inode_by_name(struct inode *, struct qstr *);
 void f2fs_set_link(struct inode *, struct f2fs_dir_entry *,
 				struct page *, struct inode *);
 int update_dent_inode(struct inode *, const struct qstr *);
-int __f2fs_add_link(struct inode *, const struct qstr *, struct inode *);
+void f2fs_update_dentry(nid_t ino, umode_t mode, struct f2fs_dentry_ptr *,
+			const struct qstr *, f2fs_hash_t , unsigned int);
+int __f2fs_add_link(struct inode *, const struct qstr *, struct inode *, nid_t,
+			umode_t);
 void f2fs_delete_entry(struct f2fs_dir_entry *, struct page *, struct inode *,
 							struct inode *);
 int f2fs_do_tmpfile(struct inode *, struct inode *);
@@ -1392,7 +1483,7 @@ bool f2fs_empty_dir(struct inode *);
 static inline int f2fs_add_link(struct dentry *dentry, struct inode *inode)
 {
 	return __f2fs_add_link(dentry->d_parent->d_inode, &dentry->d_name,
-				inode);
+				inode, inode->i_ino, inode->i_mode);
 }
 
 /*
@@ -1519,14 +1610,22 @@ int f2fs_submit_page_bio(struct f2fs_sb_info *, struct page *,
 						struct f2fs_io_info *);
 void f2fs_submit_page_mbio(struct f2fs_sb_info *, struct page *,
 						struct f2fs_io_info *);
+void set_data_blkaddr(struct dnode_of_data *);
 int reserve_new_block(struct dnode_of_data *);
 int f2fs_reserve_block(struct dnode_of_data *, pgoff_t);
-void update_extent_cache(struct dnode_of_data *);
+void f2fs_shrink_extent_tree(struct f2fs_sb_info *, int);
+void f2fs_destroy_extent_tree(struct inode *);
+void f2fs_init_extent_cache(struct inode *, struct f2fs_extent *);
+void f2fs_update_extent_cache(struct dnode_of_data *);
+void f2fs_preserve_extent_tree(struct inode *);
 struct page *find_data_page(struct inode *, pgoff_t, bool);
 struct page *get_lock_data_page(struct inode *, pgoff_t);
 struct page *get_new_data_page(struct inode *, struct page *, pgoff_t, bool);
 int do_write_data_page(struct page *, struct f2fs_io_info *);
 int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *, u64, u64);
+void init_extent_cache_info(struct f2fs_sb_info *);
+int __init create_extent_cache(void);
+void destroy_extent_cache(void);
 void f2fs_invalidate_page(struct page *, unsigned int, unsigned int);
 int f2fs_release_page(struct page *, gfp_t);
 
@@ -1554,7 +1653,7 @@ struct f2fs_stat_info {
 	struct f2fs_sb_info *sbi;
 	int all_area_segs, sit_area_segs, nat_area_segs, ssa_area_segs;
 	int main_area_segs, main_area_sections, main_area_zones;
-	int hit_ext, total_ext;
+	int hit_ext, total_ext, ext_tree, ext_node;
 	int ndirty_node, ndirty_dent, ndirty_dirs, ndirty_meta;
 	int nats, dirty_nats, sits, dirty_sits, fnids;
 	int total_count, utilization;
@@ -1566,7 +1665,9 @@ struct f2fs_stat_info {
 	int dirty_count, node_pages, meta_pages;
 	int prefree_count, call_count, cp_count;
 	int tot_segs, node_segs, data_segs, free_segs, free_secs;
+	int bg_node_segs, bg_data_segs;
 	int tot_blks, data_blks, node_blks;
+	int bg_data_blks, bg_node_blks;
 	int curseg[NR_CURSEG_TYPE];
 	int cursec[NR_CURSEG_TYPE];
 	int curzone[NR_CURSEG_TYPE];
@@ -1615,31 +1716,36 @@ static inline struct f2fs_stat_info *F2FS_STAT(struct f2fs_sb_info *sbi)
 		((sbi)->block_count[(curseg)->alloc_type]++)
 #define stat_inc_inplace_blocks(sbi)					\
 		(atomic_inc(&(sbi)->inplace_count))
-#define stat_inc_seg_count(sbi, type)					\
+#define stat_inc_seg_count(sbi, type, gc_type)				\
 	do {								\
 		struct f2fs_stat_info *si = F2FS_STAT(sbi);		\
 		(si)->tot_segs++;					\
-		if (type == SUM_TYPE_DATA)				\
+		if (type == SUM_TYPE_DATA) {				\
 			si->data_segs++;				\
-		else							\
+			si->bg_data_segs += (gc_type == BG_GC) ? 1 : 0;	\
+		} else {						\
 			si->node_segs++;				\
+			si->bg_node_segs += (gc_type == BG_GC) ? 1 : 0;	\
+		}							\
 	} while (0)
 
 #define stat_inc_tot_blk_count(si, blks)				\
 	(si->tot_blks += (blks))
 
-#define stat_inc_data_blk_count(sbi, blks)				\
+#define stat_inc_data_blk_count(sbi, blks, gc_type)			\
 	do {								\
 		struct f2fs_stat_info *si = F2FS_STAT(sbi);		\
 		stat_inc_tot_blk_count(si, blks);			\
 		si->data_blks += (blks);				\
+		si->bg_data_blks += (gc_type == BG_GC) ? (blks) : 0;	\
 	} while (0)
 
-#define stat_inc_node_blk_count(sbi, blks)				\
+#define stat_inc_node_blk_count(sbi, blks, gc_type)			\
 	do {								\
 		struct f2fs_stat_info *si = F2FS_STAT(sbi);		\
 		stat_inc_tot_blk_count(si, blks);			\
 		si->node_blks += (blks);				\
+		si->bg_node_blks += (gc_type == BG_GC) ? (blks) : 0;	\
 	} while (0)
 
 int f2fs_build_stats(struct f2fs_sb_info *);
@@ -1661,10 +1767,10 @@ void f2fs_destroy_root_stats(void);
 #define stat_inc_seg_type(sbi, curseg)
 #define stat_inc_block_count(sbi, curseg)
 #define stat_inc_inplace_blocks(sbi)
-#define stat_inc_seg_count(si, type)
+#define stat_inc_seg_count(sbi, type, gc_type)
 #define stat_inc_tot_blk_count(si, blks)
-#define stat_inc_data_blk_count(si, blks)
-#define stat_inc_node_blk_count(sbi, blks)
+#define stat_inc_data_blk_count(sbi, blks, gc_type)
+#define stat_inc_node_blk_count(sbi, blks, gc_type)
 
 static inline int f2fs_build_stats(struct f2fs_sb_info *sbi) { return 0; }
 static inline void f2fs_destroy_stats(struct f2fs_sb_info *sbi) { }
@@ -1688,6 +1794,7 @@ extern struct kmem_cache *inode_entry_slab;
  */
 bool f2fs_may_inline(struct inode *);
 void read_inline_data(struct page *, struct page *);
+bool truncate_inline_inode(struct page *, u64);
 int f2fs_read_inline_data(struct inode *, struct page *);
 int f2fs_convert_inline_page(struct dnode_of_data *, struct page *);
 int f2fs_convert_inline_inode(struct inode *);
@@ -1697,7 +1804,8 @@ struct f2fs_dir_entry *find_in_inline_dir(struct inode *, struct qstr *,
 							struct page **);
 struct f2fs_dir_entry *f2fs_parent_inline_dir(struct inode *, struct page **);
 int make_empty_inline_dir(struct inode *inode, struct inode *, struct page *);
-int f2fs_add_inline_entry(struct inode *, const struct qstr *, struct inode *);
+int f2fs_add_inline_entry(struct inode *, const struct qstr *, struct inode *,
+						nid_t, umode_t);
 void f2fs_delete_inline_entry(struct f2fs_dir_entry *, struct page *,
 						struct inode *, struct inode *);
 bool f2fs_empty_inline_dir(struct inode *);
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index df6a059..a6f3f61 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -241,6 +241,8 @@ go_write:
 		 * will be used only for fsynced inodes after checkpoint.
 		 */
 		try_to_fix_pino(inode);
+		clear_inode_flag(fi, FI_APPEND_WRITE);
+		clear_inode_flag(fi, FI_UPDATE_WRITE);
 		goto out;
 	}
 sync_nodes:
@@ -433,8 +435,12 @@ int truncate_data_blocks_range(struct dnode_of_data *dn, int count)
 			continue;
 
 		dn->data_blkaddr = NULL_ADDR;
-		update_extent_cache(dn);
+		set_data_blkaddr(dn);
+		f2fs_update_extent_cache(dn);
 		invalidate_blocks(sbi, blkaddr);
+		if (dn->ofs_in_node == 0 && IS_INODE(dn->node_page))
+			clear_inode_flag(F2FS_I(dn->inode),
+						FI_FIRST_BLOCK_WRITTEN);
 		nr_free++;
 	}
 	if (nr_free) {
@@ -454,15 +460,16 @@ void truncate_data_blocks(struct dnode_of_data *dn)
 	truncate_data_blocks_range(dn, ADDRS_PER_BLOCK);
 }
 
-static int truncate_partial_data_page(struct inode *inode, u64 from)
+static int truncate_partial_data_page(struct inode *inode, u64 from,
+								bool force)
 {
 	unsigned offset = from & (PAGE_CACHE_SIZE - 1);
 	struct page *page;
 
-	if (!offset)
+	if (!offset && !force)
 		return 0;
 
-	page = find_data_page(inode, from >> PAGE_CACHE_SHIFT, false);
+	page = find_data_page(inode, from >> PAGE_CACHE_SHIFT, force);
 	if (IS_ERR(page))
 		return 0;
 
@@ -473,7 +480,8 @@ static int truncate_partial_data_page(struct inode *inode, u64 from)
 
 	f2fs_wait_on_page_writeback(page, DATA);
 	zero_user(page, offset, PAGE_CACHE_SIZE - offset);
-	set_page_dirty(page);
+	if (!force)
+		set_page_dirty(page);
 out:
 	f2fs_put_page(page, 1);
 	return 0;
@@ -487,6 +495,7 @@ int truncate_blocks(struct inode *inode, u64 from, bool lock)
 	pgoff_t free_from;
 	int count = 0, err = 0;
 	struct page *ipage;
+	bool truncate_page = false;
 
 	trace_f2fs_truncate_blocks_enter(inode, from);
 
@@ -502,7 +511,10 @@ int truncate_blocks(struct inode *inode, u64 from, bool lock)
 	}
 
 	if (f2fs_has_inline_data(inode)) {
+		if (truncate_inline_inode(ipage, from))
+			set_page_dirty(ipage);
 		f2fs_put_page(ipage, 1);
+		truncate_page = true;
 		goto out;
 	}
 
@@ -533,7 +545,7 @@ out:
 
 	/* lastly zero out the first data page */
 	if (!err)
-		err = truncate_partial_data_page(inode, from);
+		err = truncate_partial_data_page(inode, from, truncate_page);
 
 	trace_f2fs_truncate_blocks_exit(inode, err);
 	return err;
@@ -997,6 +1009,9 @@ static int f2fs_ioc_release_volatile_write(struct file *filp)
 	if (!f2fs_is_volatile_file(inode))
 		return 0;
 
+	if (!f2fs_is_first_block_written(inode))
+		return truncate_partial_data_page(inode, 0, true);
+
 	punch_hole(inode, 0, F2FS_BLKSIZE);
 	return 0;
 }
@@ -1029,6 +1044,41 @@ static int f2fs_ioc_abort_volatile_write(struct file *filp)
 	return ret;
 }
 
+static int f2fs_ioc_shutdown(struct file *filp, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct super_block *sb = sbi->sb;
+	__u32 in;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	if (get_user(in, (__u32 __user *)arg))
+		return -EFAULT;
+
+	switch (in) {
+	case F2FS_GOING_DOWN_FULLSYNC:
+		sb = freeze_bdev(sb->s_bdev);
+		if (sb && !IS_ERR(sb)) {
+			f2fs_stop_checkpoint(sbi);
+			thaw_bdev(sb->s_bdev, sb);
+		}
+		break;
+	case F2FS_GOING_DOWN_METASYNC:
+		/* do checkpoint only */
+		f2fs_sync_fs(sb, 1);
+		f2fs_stop_checkpoint(sbi);
+		break;
+	case F2FS_GOING_DOWN_NOSYNC:
+		f2fs_stop_checkpoint(sbi);
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
 static int f2fs_ioc_fitrim(struct file *filp, unsigned long arg)
 {
 	struct inode *inode = file_inode(filp);
@@ -1078,6 +1128,8 @@ long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		return f2fs_ioc_release_volatile_write(filp);
 	case F2FS_IOC_ABORT_VOLATILE_WRITE:
 		return f2fs_ioc_abort_volatile_write(filp);
+	case F2FS_IOC_SHUTDOWN:
+		return f2fs_ioc_shutdown(filp, arg);
 	case FITRIM:
 		return f2fs_ioc_fitrim(filp, arg);
 	default:
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 76adbc3..ed58211 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -435,7 +435,7 @@ next_step:
 				set_page_dirty(node_page);
 		}
 		f2fs_put_page(node_page, 1);
-		stat_inc_node_blk_count(sbi, 1);
+		stat_inc_node_blk_count(sbi, 1, gc_type);
 	}
 
 	if (initial) {
@@ -622,7 +622,7 @@ next_step:
 			if (IS_ERR(data_page))
 				continue;
 			move_data_page(inode, data_page, gc_type);
-			stat_inc_data_blk_count(sbi, 1);
+			stat_inc_data_blk_count(sbi, 1, gc_type);
 		}
 	}
 
@@ -680,7 +680,7 @@ static void do_garbage_collect(struct f2fs_sb_info *sbi, unsigned int segno,
 	}
 	blk_finish_plug(&plug);
 
-	stat_inc_seg_count(sbi, GET_SUM_TYPE((&sum->footer)));
+	stat_inc_seg_count(sbi, GET_SUM_TYPE((&sum->footer)), gc_type);
 	stat_inc_call_count(sbi->stat_info);
 
 	f2fs_put_page(sum_page, 1);
diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c
index 1484c00..8140e4f 100644
--- a/fs/f2fs/inline.c
+++ b/fs/f2fs/inline.c
@@ -21,7 +21,7 @@ bool f2fs_may_inline(struct inode *inode)
 	if (f2fs_is_atomic_file(inode))
 		return false;
 
-	if (!S_ISREG(inode->i_mode))
+	if (!S_ISREG(inode->i_mode) && !S_ISLNK(inode->i_mode))
 		return false;
 
 	if (i_size_read(inode) > MAX_INLINE_DATA)
@@ -50,10 +50,19 @@ void read_inline_data(struct page *page, struct page *ipage)
 	SetPageUptodate(page);
 }
 
-static void truncate_inline_data(struct page *ipage)
+bool truncate_inline_inode(struct page *ipage, u64 from)
 {
+	void *addr;
+
+	if (from >= MAX_INLINE_DATA)
+		return false;
+
+	addr = inline_data_addr(ipage);
+
 	f2fs_wait_on_page_writeback(ipage, NODE);
-	memset(inline_data_addr(ipage), 0, MAX_INLINE_DATA);
+	memset(addr + from, 0, MAX_INLINE_DATA - from);
+
+	return true;
 }
 
 int f2fs_read_inline_data(struct inode *inode, struct page *page)
@@ -122,7 +131,8 @@ no_update:
 	set_page_writeback(page);
 	fio.blk_addr = dn->data_blkaddr;
 	write_data_page(page, dn, &fio);
-	update_extent_cache(dn);
+	set_data_blkaddr(dn);
+	f2fs_update_extent_cache(dn);
 	f2fs_wait_on_page_writeback(page, DATA);
 	if (dirty)
 		inode_dec_dirty_pages(dn->inode);
@@ -131,7 +141,7 @@ no_update:
 	set_inode_flag(F2FS_I(dn->inode), FI_APPEND_WRITE);
 
 	/* clear inline data and flag after data writeback */
-	truncate_inline_data(dn->inode_page);
+	truncate_inline_inode(dn->inode_page, 0);
 clear_out:
 	stat_dec_inline_inode(dn->inode);
 	f2fs_clear_inline_inode(dn->inode);
@@ -245,7 +255,7 @@ process_inline:
 	if (f2fs_has_inline_data(inode)) {
 		ipage = get_node_page(sbi, inode->i_ino);
 		f2fs_bug_on(sbi, IS_ERR(ipage));
-		truncate_inline_data(ipage);
+		truncate_inline_inode(ipage, 0);
 		f2fs_clear_inline_inode(inode);
 		update_inode(inode, ipage);
 		f2fs_put_page(ipage, 1);
@@ -363,7 +373,7 @@ static int f2fs_convert_inline_dir(struct inode *dir, struct page *ipage,
 	set_page_dirty(page);
 
 	/* clear inline dir and flag after data writeback */
-	truncate_inline_data(ipage);
+	truncate_inline_inode(ipage, 0);
 
 	stat_dec_inline_dir(dir);
 	clear_inode_flag(F2FS_I(dir), FI_INLINE_DENTRY);
@@ -380,21 +390,18 @@ out:
 }
 
 int f2fs_add_inline_entry(struct inode *dir, const struct qstr *name,
-						struct inode *inode)
+			struct inode *inode, nid_t ino, umode_t mode)
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
 	struct page *ipage;
 	unsigned int bit_pos;
 	f2fs_hash_t name_hash;
-	struct f2fs_dir_entry *de;
 	size_t namelen = name->len;
 	struct f2fs_inline_dentry *dentry_blk = NULL;
+	struct f2fs_dentry_ptr d;
 	int slots = GET_DENTRY_SLOTS(namelen);
-	struct page *page;
+	struct page *page = NULL;
 	int err = 0;
-	int i;
-
-	name_hash = f2fs_dentry_hash(name);
 
 	ipage = get_node_page(sbi, dir->i_ino);
 	if (IS_ERR(ipage))
@@ -410,32 +417,34 @@ int f2fs_add_inline_entry(struct inode *dir, const struct qstr *name,
 		goto out;
 	}
 
-	down_write(&F2FS_I(inode)->i_sem);
-	page = init_inode_metadata(inode, dir, name, ipage);
-	if (IS_ERR(page)) {
-		err = PTR_ERR(page);
-		goto fail;
+	if (inode) {
+		down_write(&F2FS_I(inode)->i_sem);
+		page = init_inode_metadata(inode, dir, name, ipage);
+		if (IS_ERR(page)) {
+			err = PTR_ERR(page);
+			goto fail;
+		}
 	}
 
 	f2fs_wait_on_page_writeback(ipage, NODE);
-	de = &dentry_blk->dentry[bit_pos];
-	de->hash_code = name_hash;
-	de->name_len = cpu_to_le16(namelen);
-	memcpy(dentry_blk->filename[bit_pos], name->name, name->len);
-	de->ino = cpu_to_le32(inode->i_ino);
-	set_de_type(de, inode);
-	for (i = 0; i < slots; i++)
-		test_and_set_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
+
+	name_hash = f2fs_dentry_hash(name);
+	make_dentry_ptr(&d, (void *)dentry_blk, 2);
+	f2fs_update_dentry(ino, mode, &d, name, name_hash, bit_pos);
+
 	set_page_dirty(ipage);
 
 	/* we don't need to mark_inode_dirty now */
-	F2FS_I(inode)->i_pino = dir->i_ino;
-	update_inode(inode, page);
-	f2fs_put_page(page, 1);
+	if (inode) {
+		F2FS_I(inode)->i_pino = dir->i_ino;
+		update_inode(inode, page);
+		f2fs_put_page(page, 1);
+	}
 
 	update_parent_metadata(dir, inode, 0);
 fail:
-	up_write(&F2FS_I(inode)->i_sem);
+	if (inode)
+		up_write(&F2FS_I(inode)->i_sem);
 
 	if (is_inode_flag_set(F2FS_I(dir), FI_UPDATE_DIR)) {
 		update_inode(dir, ipage);
diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
index 2d002e3..e622ec9 100644
--- a/fs/f2fs/inode.c
+++ b/fs/f2fs/inode.c
@@ -51,6 +51,15 @@ static void __get_inode_rdev(struct inode *inode, struct f2fs_inode *ri)
 	}
 }
 
+static bool __written_first_block(struct f2fs_inode *ri)
+{
+	block_t addr = le32_to_cpu(ri->i_addr[0]);
+
+	if (addr != NEW_ADDR && addr != NULL_ADDR)
+		return true;
+	return false;
+}
+
 static void __set_inode_rdev(struct inode *inode, struct f2fs_inode *ri)
 {
 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
@@ -130,7 +139,8 @@ static int do_read_inode(struct inode *inode)
 	fi->i_pino = le32_to_cpu(ri->i_pino);
 	fi->i_dir_level = ri->i_dir_level;
 
-	get_extent_info(&fi->ext, ri->i_ext);
+	f2fs_init_extent_cache(inode, &ri->i_ext);
+
 	get_inline_info(fi, ri);
 
 	/* check data exist */
@@ -140,6 +150,9 @@ static int do_read_inode(struct inode *inode)
 	/* get rdev by using inline_info */
 	__get_inode_rdev(inode, ri);
 
+	if (__written_first_block(ri))
+		set_inode_flag(F2FS_I(inode), FI_FIRST_BLOCK_WRITTEN);
+
 	f2fs_put_page(node_page, 1);
 
 	stat_inc_inline_inode(inode);
@@ -220,7 +233,11 @@ void update_inode(struct inode *inode, struct page *node_page)
 	ri->i_links = cpu_to_le32(inode->i_nlink);
 	ri->i_size = cpu_to_le64(i_size_read(inode));
 	ri->i_blocks = cpu_to_le64(inode->i_blocks);
+
+	read_lock(&F2FS_I(inode)->ext_lock);
 	set_raw_extent(&F2FS_I(inode)->ext, &ri->i_ext);
+	read_unlock(&F2FS_I(inode)->ext_lock);
+
 	set_raw_inline(F2FS_I(inode), ri);
 
 	ri->i_atime = cpu_to_le64(inode->i_atime.tv_sec);
@@ -328,6 +345,12 @@ void f2fs_evict_inode(struct inode *inode)
 no_delete:
 	stat_dec_inline_dir(inode);
 	stat_dec_inline_inode(inode);
+
+	/* update extent info in inode */
+	if (inode->i_nlink)
+		f2fs_preserve_extent_tree(inode);
+	f2fs_destroy_extent_tree(inode);
+
 	invalidate_mapping_pages(NODE_MAPPING(sbi), inode->i_ino, inode->i_ino);
 	if (xnid)
 		invalidate_mapping_pages(NODE_MAPPING(sbi), xnid, xnid);
diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index e79639a9..407dde3 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -14,6 +14,7 @@
 #include <linux/sched.h>
 #include <linux/ctype.h>
 #include <linux/dcache.h>
+#include <linux/namei.h>
 
 #include "f2fs.h"
 #include "node.h"
@@ -187,6 +188,44 @@ struct dentry *f2fs_get_parent(struct dentry *child)
 	return d_obtain_alias(f2fs_iget(child->d_inode->i_sb, ino));
 }
 
+static int __recover_dot_dentries(struct inode *dir, nid_t pino)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
+	struct qstr dot = QSTR_INIT(".", 1);
+	struct qstr dotdot = QSTR_INIT("..", 2);
+	struct f2fs_dir_entry *de;
+	struct page *page;
+	int err = 0;
+
+	f2fs_lock_op(sbi);
+
+	de = f2fs_find_entry(dir, &dot, &page);
+	if (de) {
+		f2fs_dentry_kunmap(dir, page);
+		f2fs_put_page(page, 0);
+	} else {
+		err = __f2fs_add_link(dir, &dot, NULL, dir->i_ino, S_IFDIR);
+		if (err)
+			goto out;
+	}
+
+	de = f2fs_find_entry(dir, &dotdot, &page);
+	if (de) {
+		f2fs_dentry_kunmap(dir, page);
+		f2fs_put_page(page, 0);
+	} else {
+		err = __f2fs_add_link(dir, &dotdot, NULL, pino, S_IFDIR);
+	}
+out:
+	if (!err) {
+		clear_inode_flag(F2FS_I(dir), FI_INLINE_DOTS);
+		mark_inode_dirty(dir);
+	}
+
+	f2fs_unlock_op(sbi);
+	return err;
+}
+
 static struct dentry *f2fs_lookup(struct inode *dir, struct dentry *dentry,
 		unsigned int flags)
 {
@@ -206,6 +245,16 @@ static struct dentry *f2fs_lookup(struct inode *dir, struct dentry *dentry,
 		inode = f2fs_iget(dir->i_sb, ino);
 		if (IS_ERR(inode))
 			return ERR_CAST(inode);
+
+		if (f2fs_has_inline_dots(inode)) {
+			int err;
+
+			err = __recover_dot_dentries(inode, dir->i_ino);
+			if (err) {
+				iget_failed(inode);
+				return ERR_PTR(err);
+			}
+		}
 	}
 
 	return d_splice_alias(inode, dentry);
@@ -247,6 +296,23 @@ fail:
 	return err;
 }
 
+static void *f2fs_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+	struct page *page;
+
+	page = page_follow_link_light(dentry, nd);
+	if (IS_ERR(page))
+		return page;
+
+	/* this is broken symlink case */
+	if (*nd_get_link(nd) == 0) {
+		kunmap(page);
+		page_cache_release(page);
+		return ERR_PTR(-ENOENT);
+	}
+	return page;
+}
+
 static int f2fs_symlink(struct inode *dir, struct dentry *dentry,
 					const char *symname)
 {
@@ -276,6 +342,17 @@ static int f2fs_symlink(struct inode *dir, struct dentry *dentry,
 	d_instantiate(dentry, inode);
 	unlock_new_inode(inode);
 
+	/*
+	 * Let's flush symlink data in order to avoid broken symlink as much as
+	 * possible. Nevertheless, fsyncing is the best way, but there is no
+	 * way to get a file descriptor in order to flush that.
+	 *
+	 * Note that, it needs to do dir->fsync to make this recoverable.
+	 * If the symlink path is stored into inline_data, there is no
+	 * performance regression.
+	 */
+	filemap_write_and_wait_range(inode->i_mapping, 0, symlen - 1);
+
 	if (IS_DIRSYNC(dir))
 		f2fs_sync_fs(sbi->sb, 1);
 	return err;
@@ -693,6 +770,8 @@ static int f2fs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
 	f2fs_unlock_op(sbi);
 
 	alloc_nid_done(sbi, inode->i_ino);
+
+	stat_inc_inline_inode(inode);
 	d_tmpfile(dentry, inode);
 	unlock_new_inode(inode);
 	return 0;
@@ -729,7 +808,7 @@ const struct inode_operations f2fs_dir_inode_operations = {
 
 const struct inode_operations f2fs_symlink_inode_operations = {
 	.readlink       = generic_readlink,
-	.follow_link    = page_follow_link_light,
+	.follow_link    = f2fs_follow_link,
 	.put_link       = page_put_link,
 	.getattr	= f2fs_getattr,
 	.setattr	= f2fs_setattr,
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 97bd9d3..8ab0cf1 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -41,7 +41,9 @@ bool available_free_memory(struct f2fs_sb_info *sbi, int type)
 	/* only uses low memory */
 	avail_ram = val.totalram - val.totalhigh;
 
-	/* give 25%, 25%, 50%, 50% memory for each components respectively */
+	/*
+	 * give 25%, 25%, 50%, 50%, 50% memory for each components respectively
+	 */
 	if (type == FREE_NIDS) {
 		mem_size = (nm_i->fcnt * sizeof(struct free_nid)) >>
 							PAGE_CACHE_SHIFT;
@@ -62,6 +64,11 @@ bool available_free_memory(struct f2fs_sb_info *sbi, int type)
 			mem_size += (sbi->im[i].ino_num *
 				sizeof(struct ino_entry)) >> PAGE_CACHE_SHIFT;
 		res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 1);
+	} else if (type == EXTENT_CACHE) {
+		mem_size = (sbi->total_ext_tree * sizeof(struct extent_tree) +
+				atomic_read(&sbi->total_ext_node) *
+				sizeof(struct extent_node)) >> PAGE_CACHE_SHIFT;
+		res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 1);
 	} else {
 		if (sbi->sb->s_bdi->dirty_exceeded)
 			return false;
@@ -494,7 +501,7 @@ int get_dnode_of_data(struct dnode_of_data *dn, pgoff_t index, int mode)
 
 	/* if inline_data is set, should not report any block indices */
 	if (f2fs_has_inline_data(dn->inode) && index) {
-		err = -EINVAL;
+		err = -ENOENT;
 		f2fs_put_page(npage[0], 1);
 		goto release_out;
 	}
@@ -995,6 +1002,7 @@ static int read_node_page(struct page *page, int rw)
 	get_node_info(sbi, page->index, &ni);
 
 	if (unlikely(ni.blk_addr == NULL_ADDR)) {
+		ClearPageUptodate(page);
 		f2fs_put_page(page, 1);
 		return -ENOENT;
 	}
@@ -1306,6 +1314,7 @@ static int f2fs_write_node_page(struct page *page,
 
 	/* This page is already truncated */
 	if (unlikely(ni.blk_addr == NULL_ADDR)) {
+		ClearPageUptodate(page);
 		dec_page_count(sbi, F2FS_DIRTY_NODES);
 		unlock_page(page);
 		return 0;
@@ -1821,6 +1830,7 @@ static void __flush_nat_entry_set(struct f2fs_sb_info *sbi,
 	struct f2fs_nat_block *nat_blk;
 	struct nat_entry *ne, *cur;
 	struct page *page = NULL;
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
 
 	/*
 	 * there are two steps to flush nat entries:
@@ -1874,7 +1884,9 @@ static void __flush_nat_entry_set(struct f2fs_sb_info *sbi,
 
 	f2fs_bug_on(sbi, set->entry_cnt);
 
+	down_write(&nm_i->nat_tree_lock);
 	radix_tree_delete(&NM_I(sbi)->nat_set_root, set->set);
+	up_write(&nm_i->nat_tree_lock);
 	kmem_cache_free(nat_entry_set_slab, set);
 }
 
@@ -1902,6 +1914,7 @@ void flush_nat_entries(struct f2fs_sb_info *sbi)
 	if (!__has_cursum_space(sum, nm_i->dirty_nat_cnt, NAT_JOURNAL))
 		remove_nats_in_journal(sbi);
 
+	down_write(&nm_i->nat_tree_lock);
 	while ((found = __gang_lookup_nat_set(nm_i,
 					set_idx, SETVEC_SIZE, setvec))) {
 		unsigned idx;
@@ -1910,6 +1923,7 @@ void flush_nat_entries(struct f2fs_sb_info *sbi)
 			__adjust_nat_entry_set(setvec[idx], &sets,
 							MAX_NAT_JENTRIES(sum));
 	}
+	up_write(&nm_i->nat_tree_lock);
 
 	/* flush dirty nats in nat entry set */
 	list_for_each_entry_safe(set, tmp, &sets, set_list)
diff --git a/fs/f2fs/node.h b/fs/f2fs/node.h
index f405bbf..c56026f 100644
--- a/fs/f2fs/node.h
+++ b/fs/f2fs/node.h
@@ -120,6 +120,7 @@ enum mem_type {
 	NAT_ENTRIES,	/* indicates the cached nat entry */
 	DIRTY_DENTS,	/* indicates dirty dentry pages */
 	INO_ENTRIES,	/* indicates inode entries */
+	EXTENT_CACHE,	/* indicates extent cache */
 	BASE_CHECK,	/* check kernel status */
 };
 
diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
index 41afb95..8d8ea99 100644
--- a/fs/f2fs/recovery.c
+++ b/fs/f2fs/recovery.c
@@ -93,10 +93,9 @@ static int recover_dentry(struct inode *inode, struct page *ipage)
 	}
 retry:
 	de = f2fs_find_entry(dir, &name, &page);
-	if (de && inode->i_ino == le32_to_cpu(de->ino)) {
-		clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
+	if (de && inode->i_ino == le32_to_cpu(de->ino))
 		goto out_unmap_put;
-	}
+
 	if (de) {
 		einode = f2fs_iget(inode->i_sb, le32_to_cpu(de->ino));
 		if (IS_ERR(einode)) {
@@ -115,7 +114,7 @@ retry:
 		iput(einode);
 		goto retry;
 	}
-	err = __f2fs_add_link(dir, &name, inode);
+	err = __f2fs_add_link(dir, &name, inode, inode->i_ino, inode->i_mode);
 	if (err)
 		goto out_err;
 
@@ -187,11 +186,7 @@ static int find_fsync_dnodes(struct f2fs_sb_info *sbi, struct list_head *head)
 			goto next;
 
 		entry = get_fsync_inode(head, ino_of_node(page));
-		if (entry) {
-			if (IS_INODE(page) && is_dent_dnode(page))
-				set_inode_flag(F2FS_I(entry->inode),
-							FI_INC_LINK);
-		} else {
+		if (!entry) {
 			if (IS_INODE(page) && is_dent_dnode(page)) {
 				err = recover_inode_page(sbi, page);
 				if (err)
@@ -212,8 +207,10 @@ static int find_fsync_dnodes(struct f2fs_sb_info *sbi, struct list_head *head)
 			if (IS_ERR(entry->inode)) {
 				err = PTR_ERR(entry->inode);
 				kmem_cache_free(fsync_entry_slab, entry);
-				if (err == -ENOENT)
+				if (err == -ENOENT) {
+					err = 0;
 					goto next;
+				}
 				break;
 			}
 			list_add_tail(&entry->list, head);
@@ -256,6 +253,7 @@ static int check_index_in_prev_nodes(struct f2fs_sb_info *sbi,
 	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;
@@ -283,17 +281,15 @@ got_it:
 	/* Use the locked dnode page and inode */
 	nid = le32_to_cpu(sum.nid);
 	if (dn->inode->i_ino == nid) {
-		struct dnode_of_data tdn = *dn;
 		tdn.nid = nid;
+		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);
-		truncate_data_blocks_range(&tdn, 1);
-		return 0;
+		goto truncate_out;
 	} else if (dn->nid == nid) {
-		struct dnode_of_data tdn = *dn;
 		tdn.ofs_in_node = le16_to_cpu(sum.ofs_in_node);
-		truncate_data_blocks_range(&tdn, 1);
-		return 0;
+		goto truncate_out;
 	}
 
 	/* Get the node page */
@@ -317,18 +313,33 @@ got_it:
 	bidx = start_bidx_of_node(offset, F2FS_I(inode)) +
 			le16_to_cpu(sum.ofs_in_node);
 
-	if (ino != dn->inode->i_ino) {
-		truncate_hole(inode, bidx, bidx + 1);
+	/*
+	 * 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 {
-		struct dnode_of_data tdn;
-		set_new_dnode(&tdn, inode, dn->inode_page, NULL, 0);
-		if (get_dnode_of_data(&tdn, bidx, LOOKUP_NODE))
-			return 0;
-		if (tdn.data_blkaddr != NULL_ADDR)
-			truncate_data_blocks_range(&tdn, 1);
-		f2fs_put_page(tdn.node_page, 1);
-	}
+	else if (dn->inode_page_locked)
+		lock_page(dn->inode_page);
+	return 0;
+
+truncate_out:
+	if (datablock_addr(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;
 }
 
@@ -384,7 +395,9 @@ static int do_recover_data(struct f2fs_sb_info *sbi, struct inode *inode,
 		src = datablock_addr(dn.node_page, dn.ofs_in_node);
 		dest = datablock_addr(page, dn.ofs_in_node);
 
-		if (src != dest && dest != NEW_ADDR && dest != NULL_ADDR) {
+		if (src != dest && dest != NEW_ADDR && dest != NULL_ADDR &&
+			dest >= MAIN_BLKADDR(sbi) && dest < MAX_BLKADDR(sbi)) {
+
 			if (src == NULL_ADDR) {
 				err = reserve_new_block(&dn);
 				/* We should not get -ENOSPC */
@@ -401,14 +414,13 @@ static int do_recover_data(struct f2fs_sb_info *sbi, struct inode *inode,
 			/* write dummy data page */
 			recover_data_page(sbi, NULL, &sum, src, dest);
 			dn.data_blkaddr = dest;
-			update_extent_cache(&dn);
+			set_data_blkaddr(&dn);
+			f2fs_update_extent_cache(&dn);
 			recovered++;
 		}
 		dn.ofs_in_node++;
 	}
 
-	/* write node page in place */
-	set_summary(&sum, dn.nid, 0, 0);
 	if (IS_INODE(dn.node_page))
 		sync_inode_page(&dn);
 
@@ -552,7 +564,7 @@ out:
 		mutex_unlock(&sbi->cp_mutex);
 	} else if (need_writecp) {
 		struct cp_control cpc = {
-			.reason = CP_SYNC,
+			.reason = CP_RECOVERY,
 		};
 		mutex_unlock(&sbi->cp_mutex);
 		write_checkpoint(sbi, &cpc);
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index daee4ab..f939660 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -205,6 +205,8 @@ retry:
 	list_add_tail(&new->list, &fi->inmem_pages);
 	inc_page_count(F2FS_I_SB(inode), F2FS_INMEM_PAGES);
 	mutex_unlock(&fi->inmem_lock);
+
+	trace_f2fs_register_inmem_page(page, INMEM);
 }
 
 void commit_inmem_pages(struct inode *inode, bool abort)
@@ -238,11 +240,13 @@ void commit_inmem_pages(struct inode *inode, bool abort)
 				f2fs_wait_on_page_writeback(cur->page, DATA);
 				if (clear_page_dirty_for_io(cur->page))
 					inode_dec_dirty_pages(inode);
+				trace_f2fs_commit_inmem_page(cur->page, INMEM);
 				do_write_data_page(cur->page, &fio);
 				submit_bio = true;
 			}
 			f2fs_put_page(cur->page, 1);
 		} else {
+			trace_f2fs_commit_inmem_page(cur->page, INMEM_DROP);
 			put_page(cur->page);
 		}
 		radix_tree_delete(&fi->inmem_root, cur->page->index);
@@ -277,6 +281,9 @@ void f2fs_balance_fs(struct f2fs_sb_info *sbi)
 
 void f2fs_balance_fs_bg(struct f2fs_sb_info *sbi)
 {
+	/* try to shrink extent cache when there is no enough memory */
+	f2fs_shrink_extent_tree(sbi, EXTENT_CACHE_SHRINK_NUMBER);
+
 	/* check the # of cached NAT entries and prefree segments */
 	if (try_to_free_nats(sbi, NAT_ENTRY_PER_BLOCK) ||
 			excess_prefree_segs(sbi) ||
@@ -549,7 +556,7 @@ static void add_discard_addrs(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 
 		end = __find_rev_next_zero_bit(dmap, max_blocks, start + 1);
 
-		if (end - start < cpc->trim_minlen)
+		if (force && end - start < cpc->trim_minlen)
 			continue;
 
 		__add_discard_entry(sbi, cpc, start, end);
@@ -1164,6 +1171,7 @@ void allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
 	curseg = CURSEG_I(sbi, type);
 
 	mutex_lock(&curseg->curseg_mutex);
+	mutex_lock(&sit_i->sentry_lock);
 
 	/* direct_io'ed data is aligned to the segment for better performance */
 	if (direct_io && curseg->next_blkoff)
@@ -1178,7 +1186,6 @@ void allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
 	 */
 	__add_sum_entry(sbi, type, sum);
 
-	mutex_lock(&sit_i->sentry_lock);
 	__refresh_next_blkoff(sbi, curseg);
 
 	stat_inc_block_count(sbi, curseg);
@@ -1730,6 +1737,9 @@ void flush_sit_entries(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 	mutex_lock(&curseg->curseg_mutex);
 	mutex_lock(&sit_i->sentry_lock);
 
+	if (!sit_i->dirty_sentries)
+		goto out;
+
 	/*
 	 * add and account sit entries of dirty bitmap in sit entry
 	 * set temporarily
@@ -1744,9 +1754,6 @@ void flush_sit_entries(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 	if (!__has_cursum_space(sum, sit_i->dirty_sentries, SIT_JOURNAL))
 		remove_sits_in_journal(sbi);
 
-	if (!sit_i->dirty_sentries)
-		goto out;
-
 	/*
 	 * there are two steps to flush sit entries:
 	 * #1, flush sit entries to journal in current cold data summary block.
diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index 7fd3511..85d7fa7 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -336,7 +336,8 @@ static inline void __set_free(struct f2fs_sb_info *sbi, unsigned int segno)
 	clear_bit(segno, free_i->free_segmap);
 	free_i->free_segments++;
 
-	next = find_next_bit(free_i->free_segmap, MAIN_SEGS(sbi), start_segno);
+	next = find_next_bit(free_i->free_segmap,
+			start_segno + sbi->segs_per_sec, start_segno);
 	if (next >= start_segno + sbi->segs_per_sec) {
 		clear_bit(secno, free_i->free_secmap);
 		free_i->free_sections++;
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index f2fe666..160b883 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -57,6 +57,8 @@ enum {
 	Opt_flush_merge,
 	Opt_nobarrier,
 	Opt_fastboot,
+	Opt_extent_cache,
+	Opt_noinline_data,
 	Opt_err,
 };
 
@@ -78,6 +80,8 @@ static match_table_t f2fs_tokens = {
 	{Opt_flush_merge, "flush_merge"},
 	{Opt_nobarrier, "nobarrier"},
 	{Opt_fastboot, "fastboot"},
+	{Opt_extent_cache, "extent_cache"},
+	{Opt_noinline_data, "noinline_data"},
 	{Opt_err, NULL},
 };
 
@@ -367,6 +371,12 @@ static int parse_options(struct super_block *sb, char *options)
 		case Opt_fastboot:
 			set_opt(sbi, FASTBOOT);
 			break;
+		case Opt_extent_cache:
+			set_opt(sbi, EXTENT_CACHE);
+			break;
+		case Opt_noinline_data:
+			clear_opt(sbi, INLINE_DATA);
+			break;
 		default:
 			f2fs_msg(sb, KERN_ERR,
 				"Unrecognized mount option \"%s\" or missing value",
@@ -392,7 +402,7 @@ static struct inode *f2fs_alloc_inode(struct super_block *sb)
 	atomic_set(&fi->dirty_pages, 0);
 	fi->i_current_depth = 1;
 	fi->i_advise = 0;
-	rwlock_init(&fi->ext.ext_lock);
+	rwlock_init(&fi->ext_lock);
 	init_rwsem(&fi->i_sem);
 	INIT_RADIX_TREE(&fi->inmem_root, GFP_NOFS);
 	INIT_LIST_HEAD(&fi->inmem_pages);
@@ -591,6 +601,8 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
 		seq_puts(seq, ",disable_ext_identify");
 	if (test_opt(sbi, INLINE_DATA))
 		seq_puts(seq, ",inline_data");
+	else
+		seq_puts(seq, ",noinline_data");
 	if (test_opt(sbi, INLINE_DENTRY))
 		seq_puts(seq, ",inline_dentry");
 	if (!f2fs_readonly(sbi->sb) && test_opt(sbi, FLUSH_MERGE))
@@ -599,6 +611,8 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
 		seq_puts(seq, ",nobarrier");
 	if (test_opt(sbi, FASTBOOT))
 		seq_puts(seq, ",fastboot");
+	if (test_opt(sbi, EXTENT_CACHE))
+		seq_puts(seq, ",extent_cache");
 	seq_printf(seq, ",active_logs=%u", sbi->active_logs);
 
 	return 0;
@@ -959,7 +973,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 	struct buffer_head *raw_super_buf;
 	struct inode *root;
 	long err = -EINVAL;
-	bool retry = true;
+	bool retry = true, need_fsck = false;
 	char *options = NULL;
 	int i;
 
@@ -984,6 +998,7 @@ try_onemore:
 	sbi->active_logs = NR_CURSEG_TYPE;
 
 	set_opt(sbi, BG_GC);
+	set_opt(sbi, INLINE_DATA);
 
 #ifdef CONFIG_F2FS_FS_XATTR
 	set_opt(sbi, XATTR_USER);
@@ -1020,7 +1035,6 @@ try_onemore:
 	sbi->raw_super = raw_super;
 	sbi->raw_super_buf = raw_super_buf;
 	mutex_init(&sbi->gc_mutex);
-	mutex_init(&sbi->writepages);
 	mutex_init(&sbi->cp_mutex);
 	init_rwsem(&sbi->node_write);
 	clear_sbi_flag(sbi, SBI_POR_DOING);
@@ -1072,6 +1086,8 @@ try_onemore:
 	INIT_LIST_HEAD(&sbi->dir_inode_list);
 	spin_lock_init(&sbi->dir_inode_lock);
 
+	init_extent_cache_info(sbi);
+
 	init_ino_entry_info(sbi);
 
 	/* setup f2fs internal modules */
@@ -1146,9 +1162,6 @@ try_onemore:
 	if (err)
 		goto free_proc;
 
-	if (!retry)
-		set_sbi_flag(sbi, SBI_NEED_FSCK);
-
 	/* recover fsynced data */
 	if (!test_opt(sbi, DISABLE_ROLL_FORWARD)) {
 		/*
@@ -1160,8 +1173,13 @@ try_onemore:
 			err = -EROFS;
 			goto free_kobj;
 		}
+
+		if (need_fsck)
+			set_sbi_flag(sbi, SBI_NEED_FSCK);
+
 		err = recover_fsync_data(sbi);
 		if (err) {
+			need_fsck = true;
 			f2fs_msg(sb, KERN_ERR,
 				"Cannot recover all fsync data errno=%ld", err);
 			goto free_kobj;
@@ -1212,7 +1230,7 @@ free_sbi:
 
 	/* give only one another chance */
 	if (retry) {
-		retry = 0;
+		retry = false;
 		shrink_dcache_sb(sb);
 		goto try_onemore;
 	}
@@ -1278,10 +1296,13 @@ static int __init init_f2fs_fs(void)
 	err = create_checkpoint_caches();
 	if (err)
 		goto free_segment_manager_caches;
+	err = create_extent_cache();
+	if (err)
+		goto free_checkpoint_caches;
 	f2fs_kset = kset_create_and_add("f2fs", NULL, fs_kobj);
 	if (!f2fs_kset) {
 		err = -ENOMEM;
-		goto free_checkpoint_caches;
+		goto free_extent_cache;
 	}
 	err = register_filesystem(&f2fs_fs_type);
 	if (err)
@@ -1292,6 +1313,8 @@ static int __init init_f2fs_fs(void)
 
 free_kset:
 	kset_unregister(f2fs_kset);
+free_extent_cache:
+	destroy_extent_cache();
 free_checkpoint_caches:
 	destroy_checkpoint_caches();
 free_segment_manager_caches:
@@ -1309,6 +1332,7 @@ static void __exit exit_f2fs_fs(void)
 	remove_proc_entry("fs/f2fs", NULL);
 	f2fs_destroy_root_stats();
 	unregister_filesystem(&f2fs_fs_type);
+	destroy_extent_cache();
 	destroy_checkpoint_caches();
 	destroy_segment_manager_caches();
 	destroy_node_manager_caches();
diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c
index 5072bf9..b0fd2f2 100644
--- a/fs/f2fs/xattr.c
+++ b/fs/f2fs/xattr.c
@@ -135,7 +135,8 @@ static int f2fs_xattr_advise_get(struct dentry *dentry, const char *name,
 	if (strcmp(name, "") != 0)
 		return -EINVAL;
 
-	*((char *)buffer) = F2FS_I(inode)->i_advise;
+	if (buffer)
+		*((char *)buffer) = F2FS_I(inode)->i_advise;
 	return sizeof(char);
 }
 
@@ -152,6 +153,7 @@ static int f2fs_xattr_advise_set(struct dentry *dentry, const char *name,
 		return -EINVAL;
 
 	F2FS_I(inode)->i_advise |= *(char *)value;
+	mark_inode_dirty(inode);
 	return 0;
 }