Merge tag 'for-f2fs-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs

Pull f2fs updates from Jaegeuk Kim:
"This patch-set includes the following major enhancement patches.
- introduce large directory support
- introduce f2fs_issue_flush to merge redundant flush commands
- merge write IOs as much as possible aligned to the segment
- add sysfs entries to tune the f2fs configuration
- use radix_tree for the free_nid_list to reduce in-memory operations
- remove costly bit operations in f2fs_find_entry
- enhance the readahead flow for CP/NAT/SIT/SSA blocks

The other bug fixes are as follows:
- recover xattr node blocks correctly after sudden-power-cut
- fix to calculate the maximum number of node ids
- enhance to handle many error cases

And, there are a bunch of cleanups"

* tag 'for-f2fs-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (62 commits)
f2fs: fix wrong statistics of inline data
f2fs: check the acl's validity before setting
f2fs: introduce f2fs_issue_flush to avoid redundant flush issue
f2fs: fix to cover io->bio with io_rwsem
f2fs: fix error path when fail to read inline data
f2fs: use list_for_each_entry{_safe} for simplyfying code
f2fs: avoid free slab cache under spinlock
f2fs: avoid unneeded lookup when xattr name length is too long
f2fs: avoid unnecessary bio submit when wait page writeback
f2fs: return -EIO when node id is not matched
f2fs: avoid RECLAIM_FS-ON-W warning
f2fs: skip unnecessary node writes during fsync
f2fs: introduce fi->i_sem to protect fi's info
f2fs: change reclaim rate in percentage
f2fs: add missing documentation for dir_level
f2fs: remove unnecessary threshold
f2fs: throttle the memory footprint with a sysfs entry
f2fs: avoid to drop nat entries due to the negative nr_shrink
f2fs: call f2fs_wait_on_page_writeback instead of native function
f2fs: introduce nr_pages_to_write for segment alignment
...

Documentation/ABI/testing/sysfs-fs-f2fs

···
 Contact:	"Jaegeuk Kim" <[e-mail]>
 Description:
 		 Controls the number of trials to find a victim segment.
+
+What:		/sys/fs/f2fs/<disk>/dir_level
+Date:		March 2014
+Contact:	"Jaegeuk Kim" <[e-mail]>
+Description:
+		 Controls the directory level for large directory.
+
+What:		/sys/fs/f2fs/<disk>/ram_thresh
+Date:		March 2014
+Contact:	"Jaegeuk Kim" <[e-mail]>
+Description:
+		 Controls the memory footprint used by f2fs.

Documentation/filesystems/f2fs.txt

···
 inline_xattr           Enable the inline xattrs feature.
 inline_data            Enable the inline data feature: New created small(<~3.4k)
                        files can be written into inode block.
+flush_merge	       Merge concurrent cache_flush commands as much as possible
+                       to eliminate redundant command issues. If the underlying
+		       device handles the cache_flush command relatively slowly,
+		       recommend to enable this option.
 
 ================================================================================
 DEBUGFS ENTRIES
···
 
  reclaim_segments             This parameter controls the number of prefree
                               segments to be reclaimed. If the number of prefree
-			      segments is larger than this number, f2fs tries to
-			      conduct checkpoint to reclaim the prefree segments
-			      to free segments. By default, 100 segments, 200MB.
+			      segments is larger than the number of segments
+			      in the proportion to the percentage over total
+			      volume size, f2fs tries to conduct checkpoint to
+			      reclaim the prefree segments to free segments.
+			      By default, 5% over total # of segments.
 
  max_small_discards	      This parameter controls the number of discard
 			      commands that consist small blocks less than 2MB.
···
 			      find a victim segment when conducting SSR and
 			      cleaning operations. The default value is 4096
 			      which covers 8GB block address range.
+
+ dir_level                    This parameter controls the directory level to
+			      support large directory. If a directory has a
+			      number of files, it can reduce the file lookup
+			      latency by increasing this dir_level value.
+			      Otherwise, it needs to decrease this value to
+			      reduce the space overhead. The default value is 0.
+
+ ram_thresh                   This parameter controls the memory footprint used
+			      by free nids and cached nat entries. By default,
+			      10 is set, which indicates 10 MB / 1 GB RAM.
 
 ================================================================================
 USAGE
···
   # of blocks in level #n = |
                             `- 4, Otherwise
 
-                             ,- 2^n, if n < MAX_DIR_HASH_DEPTH / 2,
+                             ,- 2^ (n + dir_level),
+			     |            if n < MAX_DIR_HASH_DEPTH / 2,
   # of buckets in level #n = |
-                             `- 2^((MAX_DIR_HASH_DEPTH / 2) - 1), Otherwise
+                             `- 2^((MAX_DIR_HASH_DEPTH / 2 + dir_level) - 1),
+			                  Otherwise
 
 When F2FS finds a file name in a directory, at first a hash value of the file
 name is calculated. Then, F2FS scans the hash table in level #0 to find the

fs/f2fs/acl.c

···
 
 	retval = f2fs_getxattr(inode, name_index, "", NULL, 0);
 	if (retval > 0) {
-		value = kmalloc(retval, GFP_KERNEL);
+		value = kmalloc(retval, GFP_F2FS_ZERO);
 		if (!value)
 			return ERR_PTR(-ENOMEM);
 		retval = f2fs_getxattr(inode, name_index, "", value, retval);
···
 	void *value = NULL;
 	size_t size = 0;
 	int error;
+
+	if (acl) {
+		error = posix_acl_valid(acl);
+		if (error < 0)
+			return error;
+	}
 
 	switch (type) {
 	case ACL_TYPE_ACCESS:

fs/f2fs/checkpoint.c

···
 	struct address_space *mapping = META_MAPPING(sbi);
 	struct page *page = NULL;
 repeat:
-	page = grab_cache_page(mapping, index);
+	page = grab_cache_page_write_begin(mapping, index, AOP_FLAG_NOFS);
 	if (!page) {
 		cond_resched();
 		goto repeat;
 	}
 
-	/* We wait writeback only inside grab_meta_page() */
-	wait_on_page_writeback(page);
 	SetPageUptodate(page);
 	return page;
 }
···
 	return page;
 }
 
+inline int get_max_meta_blks(struct f2fs_sb_info *sbi, int type)
+{
+	switch (type) {
+	case META_NAT:
+		return NM_I(sbi)->max_nid / NAT_ENTRY_PER_BLOCK;
+	case META_SIT:
+		return SIT_BLK_CNT(sbi);
+	case META_SSA:
+	case META_CP:
+		return 0;
+	default:
+		BUG();
+	}
+}
+
+/*
+ * Readahead CP/NAT/SIT/SSA pages
+ */
+int ra_meta_pages(struct f2fs_sb_info *sbi, int start, int nrpages, int type)
+{
+	block_t prev_blk_addr = 0;
+	struct page *page;
+	int blkno = start;
+	int max_blks = get_max_meta_blks(sbi, type);
+
+	struct f2fs_io_info fio = {
+		.type = META,
+		.rw = READ_SYNC | REQ_META | REQ_PRIO
+	};
+
+	for (; nrpages-- > 0; blkno++) {
+		block_t blk_addr;
+
+		switch (type) {
+		case META_NAT:
+			/* get nat block addr */
+			if (unlikely(blkno >= max_blks))
+				blkno = 0;
+			blk_addr = current_nat_addr(sbi,
+					blkno * NAT_ENTRY_PER_BLOCK);
+			break;
+		case META_SIT:
+			/* get sit block addr */
+			if (unlikely(blkno >= max_blks))
+				goto out;
+			blk_addr = current_sit_addr(sbi,
+					blkno * SIT_ENTRY_PER_BLOCK);
+			if (blkno != start && prev_blk_addr + 1 != blk_addr)
+				goto out;
+			prev_blk_addr = blk_addr;
+			break;
+		case META_SSA:
+		case META_CP:
+			/* get ssa/cp block addr */
+			blk_addr = blkno;
+			break;
+		default:
+			BUG();
+		}
+
+		page = grab_cache_page(META_MAPPING(sbi), blk_addr);
+		if (!page)
+			continue;
+		if (PageUptodate(page)) {
+			mark_page_accessed(page);
+			f2fs_put_page(page, 1);
+			continue;
+		}
+
+		f2fs_submit_page_mbio(sbi, page, blk_addr, &fio);
+		mark_page_accessed(page);
+		f2fs_put_page(page, 0);
+	}
+out:
+	f2fs_submit_merged_bio(sbi, META, READ);
+	return blkno - start;
+}
+
 static int f2fs_write_meta_page(struct page *page,
 				struct writeback_control *wbc)
 {
 	struct inode *inode = page->mapping->host;
 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 
-	/* Should not write any meta pages, if any IO error was occurred */
-	if (unlikely(sbi->por_doing ||
-			is_set_ckpt_flags(F2FS_CKPT(sbi), CP_ERROR_FLAG)))
+	if (unlikely(sbi->por_doing))
 		goto redirty_out;
-
 	if (wbc->for_reclaim)
 		goto redirty_out;
 
-	wait_on_page_writeback(page);
+	/* Should not write any meta pages, if any IO error was occurred */
+	if (unlikely(is_set_ckpt_flags(F2FS_CKPT(sbi), CP_ERROR_FLAG)))
+		goto no_write;
 
+	f2fs_wait_on_page_writeback(page, META);
 	write_meta_page(sbi, page);
+no_write:
 	dec_page_count(sbi, F2FS_DIRTY_META);
 	unlock_page(page);
 	return 0;
···
 redirty_out:
 	dec_page_count(sbi, F2FS_DIRTY_META);
 	wbc->pages_skipped++;
+	account_page_redirty(page);
 	set_page_dirty(page);
 	return AOP_WRITEPAGE_ACTIVATE;
 }
···
 				struct writeback_control *wbc)
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(mapping->host->i_sb);
-	int nrpages = MAX_BIO_BLOCKS(max_hw_blocks(sbi));
-	long written;
-
-	if (wbc->for_kupdate)
-		return 0;
+	long diff, written;
 
 	/* collect a number of dirty meta pages and write together */
-	if (get_pages(sbi, F2FS_DIRTY_META) < nrpages)
-		return 0;
+	if (wbc->for_kupdate ||
+		get_pages(sbi, F2FS_DIRTY_META) < nr_pages_to_skip(sbi, META))
+		goto skip_write;
 
 	/* if mounting is failed, skip writing node pages */
 	mutex_lock(&sbi->cp_mutex);
-	written = sync_meta_pages(sbi, META, nrpages);
+	diff = nr_pages_to_write(sbi, META, wbc);
+	written = sync_meta_pages(sbi, META, wbc->nr_to_write);
 	mutex_unlock(&sbi->cp_mutex);
-	wbc->nr_to_write -= written;
+	wbc->nr_to_write = max((long)0, wbc->nr_to_write - written - diff);
+	return 0;
+
+skip_write:
+	wbc->pages_skipped += get_pages(sbi, F2FS_DIRTY_META);
 	return 0;
 }
 
···
 
 		for (i = 0; i < nr_pages; i++) {
 			struct page *page = pvec.pages[i];
+
 			lock_page(page);
-			f2fs_bug_on(page->mapping != mapping);
-			f2fs_bug_on(!PageDirty(page));
-			clear_page_dirty_for_io(page);
+
+			if (unlikely(page->mapping != mapping)) {
+continue_unlock:
+				unlock_page(page);
+				continue;
+			}
+			if (!PageDirty(page)) {
+				/* someone wrote it for us */
+				goto continue_unlock;
+			}
+
+			if (!clear_page_dirty_for_io(page))
+				goto continue_unlock;
+
 			if (f2fs_write_meta_page(page, &wbc)) {
 				unlock_page(page);
 				break;
···
 
 void add_orphan_inode(struct f2fs_sb_info *sbi, nid_t ino)
 {
-	struct list_head *head, *this;
-	struct orphan_inode_entry *new = NULL, *orphan = NULL;
+	struct list_head *head;
+	struct orphan_inode_entry *new, *orphan;
 
 	new = f2fs_kmem_cache_alloc(orphan_entry_slab, GFP_ATOMIC);
 	new->ino = ino;
 
 	spin_lock(&sbi->orphan_inode_lock);
 	head = &sbi->orphan_inode_list;
-	list_for_each(this, head) {
-		orphan = list_entry(this, struct orphan_inode_entry, list);
+	list_for_each_entry(orphan, head, list) {
 		if (orphan->ino == ino) {
 			spin_unlock(&sbi->orphan_inode_lock);
 			kmem_cache_free(orphan_entry_slab, new);
···
 
 		if (orphan->ino > ino)
 			break;
-		orphan = NULL;
 	}
 
-	/* add new_oentry into list which is sorted by inode number */
-	if (orphan)
-		list_add(&new->list, this->prev);
-	else
-		list_add_tail(&new->list, head);
+	/* add new orphan entry into list which is sorted by inode number */
+	list_add_tail(&new->list, &orphan->list);
 	spin_unlock(&sbi->orphan_inode_lock);
 }
 
···
 	list_for_each_entry(orphan, head, list) {
 		if (orphan->ino == ino) {
 			list_del(&orphan->list);
-			kmem_cache_free(orphan_entry_slab, orphan);
 			f2fs_bug_on(sbi->n_orphans == 0);
 			sbi->n_orphans--;
-			break;
+			spin_unlock(&sbi->orphan_inode_lock);
+			kmem_cache_free(orphan_entry_slab, orphan);
+			return;
 		}
 	}
 	spin_unlock(&sbi->orphan_inode_lock);
···
 	sbi->por_doing = true;
 	start_blk = __start_cp_addr(sbi) + 1;
 	orphan_blkaddr = __start_sum_addr(sbi) - 1;
+
+	ra_meta_pages(sbi, start_blk, orphan_blkaddr, META_CP);
 
 	for (i = 0; i < orphan_blkaddr; i++) {
 		struct page *page = get_meta_page(sbi, start_blk + i);
···
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 	struct list_head *head = &sbi->dir_inode_list;
-	struct list_head *this;
+	struct dir_inode_entry *entry;
 
-	list_for_each(this, head) {
-		struct dir_inode_entry *entry;
-		entry = list_entry(this, struct dir_inode_entry, list);
+	list_for_each_entry(entry, head, list)
 		if (unlikely(entry->inode == inode))
 			return -EEXIST;
-	}
+
 	list_add_tail(&new->list, head);
 	stat_inc_dirty_dir(sbi);
 	return 0;
···
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 	struct dir_inode_entry *new;
+	int ret = 0;
 
 	if (!S_ISDIR(inode->i_mode))
 		return;
···
 	INIT_LIST_HEAD(&new->list);
 
 	spin_lock(&sbi->dir_inode_lock);
-	if (__add_dirty_inode(inode, new))
-		kmem_cache_free(inode_entry_slab, new);
-
-	inc_page_count(sbi, F2FS_DIRTY_DENTS);
+	ret = __add_dirty_inode(inode, new);
 	inode_inc_dirty_dents(inode);
 	SetPagePrivate(page);
 	spin_unlock(&sbi->dir_inode_lock);
+
+	if (ret)
+		kmem_cache_free(inode_entry_slab, new);
 }
 
 void add_dirty_dir_inode(struct inode *inode)
···
 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 	struct dir_inode_entry *new =
 			f2fs_kmem_cache_alloc(inode_entry_slab, GFP_NOFS);
+	int ret = 0;
 
 	new->inode = inode;
 	INIT_LIST_HEAD(&new->list);
 
 	spin_lock(&sbi->dir_inode_lock);
-	if (__add_dirty_inode(inode, new))
-		kmem_cache_free(inode_entry_slab, new);
+	ret = __add_dirty_inode(inode, new);
 	spin_unlock(&sbi->dir_inode_lock);
+
+	if (ret)
+		kmem_cache_free(inode_entry_slab, new);
 }
 
 void remove_dirty_dir_inode(struct inode *inode)
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
-
-	struct list_head *this, *head;
+	struct list_head *head;
+	struct dir_inode_entry *entry;
 
 	if (!S_ISDIR(inode->i_mode))
 		return;
 
 	spin_lock(&sbi->dir_inode_lock);
-	if (atomic_read(&F2FS_I(inode)->dirty_dents)) {
+	if (get_dirty_dents(inode)) {
 		spin_unlock(&sbi->dir_inode_lock);
 		return;
 	}
 
 	head = &sbi->dir_inode_list;
-	list_for_each(this, head) {
-		struct dir_inode_entry *entry;
-		entry = list_entry(this, struct dir_inode_entry, list);
+	list_for_each_entry(entry, head, list) {
 		if (entry->inode == inode) {
 			list_del(&entry->list);
-			kmem_cache_free(inode_entry_slab, entry);
 			stat_dec_dirty_dir(sbi);
-			break;
+			spin_unlock(&sbi->dir_inode_lock);
+			kmem_cache_free(inode_entry_slab, entry);
+			goto done;
 		}
 	}
 	spin_unlock(&sbi->dir_inode_lock);
 
+done:
 	/* Only from the recovery routine */
 	if (is_inode_flag_set(F2FS_I(inode), FI_DELAY_IPUT)) {
 		clear_inode_flag(F2FS_I(inode), FI_DELAY_IPUT);
···
 struct inode *check_dirty_dir_inode(struct f2fs_sb_info *sbi, nid_t ino)
 {
 
-	struct list_head *this, *head;
+	struct list_head *head;
 	struct inode *inode = NULL;
+	struct dir_inode_entry *entry;
 
 	spin_lock(&sbi->dir_inode_lock);
 
 	head = &sbi->dir_inode_list;
-	list_for_each(this, head) {
-		struct dir_inode_entry *entry;
-		entry = list_entry(this, struct dir_inode_entry, list);
+	list_for_each_entry(entry, head, list) {
 		if (entry->inode->i_ino == ino) {
 			inode = entry->inode;
 			break;
···
 	inode = igrab(entry->inode);
 	spin_unlock(&sbi->dir_inode_lock);
 	if (inode) {
-		filemap_flush(inode->i_mapping);
+		filemap_fdatawrite(inode->i_mapping);
 		iput(inode);
 	} else {
 		/*
···
 	unblock_operations(sbi);
 	mutex_unlock(&sbi->cp_mutex);
 
+	stat_inc_cp_count(sbi->stat_info);
 	trace_f2fs_write_checkpoint(sbi->sb, is_umount, "finish checkpoint");
 }
 
···
 int __init create_checkpoint_caches(void)
 {
 	orphan_entry_slab = f2fs_kmem_cache_create("f2fs_orphan_entry",
-			sizeof(struct orphan_inode_entry), NULL);
+			sizeof(struct orphan_inode_entry));
 	if (!orphan_entry_slab)
 		return -ENOMEM;
 	inode_entry_slab = f2fs_kmem_cache_create("f2fs_dirty_dir_entry",
-			sizeof(struct dir_inode_entry), NULL);
+			sizeof(struct dir_inode_entry));
 	if (!inode_entry_slab) {
 		kmem_cache_destroy(orphan_entry_slab);
 		return -ENOMEM;

fs/f2fs/data.c

···
 
 static void f2fs_write_end_io(struct bio *bio, int err)
 {
-	struct f2fs_sb_info *sbi = F2FS_SB(bio->bi_io_vec->bv_page->mapping->host->i_sb);
+	struct f2fs_sb_info *sbi = bio->bi_private;
 	struct bio_vec *bvec;
 	int i;
 
···
 		if (unlikely(err)) {
 			SetPageError(page);
 			set_bit(AS_EIO, &page->mapping->flags);
-			set_ckpt_flags(sbi->ckpt, CP_ERROR_FLAG);
-			sbi->sb->s_flags |= MS_RDONLY;
+			f2fs_stop_checkpoint(sbi);
 		}
 		end_page_writeback(page);
 		dec_page_count(sbi, F2FS_WRITEBACK);
 	}
 
-	if (bio->bi_private)
-		complete(bio->bi_private);
+	if (sbi->wait_io) {
+		complete(sbi->wait_io);
+		sbi->wait_io = NULL;
+	}
 
 	if (!get_pages(sbi, F2FS_WRITEBACK) &&
 			!list_empty(&sbi->cp_wait.task_list))
···
 	bio->bi_bdev = sbi->sb->s_bdev;
 	bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(sbi, blk_addr);
 	bio->bi_end_io = is_read ? f2fs_read_end_io : f2fs_write_end_io;
+	bio->bi_private = sbi;
 
 	return bio;
 }
···
 		 */
 		if (fio->type == META_FLUSH) {
 			DECLARE_COMPLETION_ONSTACK(wait);
-			io->bio->bi_private = &wait;
+			io->sbi->wait_io = &wait;
 			submit_bio(rw, io->bio);
 			wait_for_completion(&wait);
 		} else {
···
 
 	io = is_read_io(rw) ? &sbi->read_io : &sbi->write_io[btype];
 
-	mutex_lock(&io->io_mutex);
+	down_write(&io->io_rwsem);
 
 	/* change META to META_FLUSH in the checkpoint procedure */
 	if (type >= META_FLUSH) {
···
 		io->fio.rw = WRITE_FLUSH_FUA | REQ_META | REQ_PRIO;
 	}
 	__submit_merged_bio(io);
-	mutex_unlock(&io->io_mutex);
+	up_write(&io->io_rwsem);
 }
 
 /*
···
 
 	verify_block_addr(sbi, blk_addr);
 
-	mutex_lock(&io->io_mutex);
+	down_write(&io->io_rwsem);
 
 	if (!is_read)
 		inc_page_count(sbi, F2FS_WRITEBACK);
···
 
 	io->last_block_in_bio = blk_addr;
 
-	mutex_unlock(&io->io_mutex);
+	up_write(&io->io_rwsem);
 	trace_f2fs_submit_page_mbio(page, fio->rw, fio->type, blk_addr);
 }
 
···
 	 */
 	offset = i_size & (PAGE_CACHE_SIZE - 1);
 	if ((page->index >= end_index + 1) || !offset) {
-		if (S_ISDIR(inode->i_mode)) {
-			dec_page_count(sbi, F2FS_DIRTY_DENTS);
-			inode_dec_dirty_dents(inode);
-		}
+		inode_dec_dirty_dents(inode);
 		goto out;
 	}
 
 	zero_user_segment(page, offset, PAGE_CACHE_SIZE);
 write:
-	if (unlikely(sbi->por_doing)) {
-		err = AOP_WRITEPAGE_ACTIVATE;
+	if (unlikely(sbi->por_doing))
 		goto redirty_out;
-	}
 
 	/* Dentry blocks are controlled by checkpoint */
 	if (S_ISDIR(inode->i_mode)) {
-		dec_page_count(sbi, F2FS_DIRTY_DENTS);
 		inode_dec_dirty_dents(inode);
 		err = do_write_data_page(page, &fio);
-	} else {
-		f2fs_lock_op(sbi);
-
-		if (f2fs_has_inline_data(inode) || f2fs_may_inline(inode)) {
-			err = f2fs_write_inline_data(inode, page, offset);
-			f2fs_unlock_op(sbi);
-			goto out;
-		} else {
-			err = do_write_data_page(page, &fio);
-		}
-
-		f2fs_unlock_op(sbi);
-		need_balance_fs = true;
+		goto done;
 	}
-	if (err == -ENOENT)
-		goto out;
-	else if (err)
+
+	if (!wbc->for_reclaim)
+		need_balance_fs = true;
+	else if (has_not_enough_free_secs(sbi, 0))
 		goto redirty_out;
 
-	if (wbc->for_reclaim) {
-		f2fs_submit_merged_bio(sbi, DATA, WRITE);
-		need_balance_fs = false;
-	}
+	f2fs_lock_op(sbi);
+	if (f2fs_has_inline_data(inode) || f2fs_may_inline(inode))
+		err = f2fs_write_inline_data(inode, page, offset);
+	else
+		err = do_write_data_page(page, &fio);
+	f2fs_unlock_op(sbi);
+done:
+	if (err && err != -ENOENT)
+		goto redirty_out;
 
 	clear_cold_data(page);
 out:
···
 
 redirty_out:
 	wbc->pages_skipped++;
+	account_page_redirty(page);
 	set_page_dirty(page);
-	return err;
+	return AOP_WRITEPAGE_ACTIVATE;
 }
-
-#define MAX_DESIRED_PAGES_WP	4096
 
 static int __f2fs_writepage(struct page *page, struct writeback_control *wbc,
 			void *data)
···
 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 	bool locked = false;
 	int ret;
-	long excess_nrtw = 0, desired_nrtw;
+	long diff;
 
 	/* deal with chardevs and other special file */
 	if (!mapping->a_ops->writepage)
 		return 0;
 
-	if (wbc->nr_to_write < MAX_DESIRED_PAGES_WP) {
-		desired_nrtw = MAX_DESIRED_PAGES_WP;
-		excess_nrtw = desired_nrtw - wbc->nr_to_write;
-		wbc->nr_to_write = desired_nrtw;
-	}
+	if (S_ISDIR(inode->i_mode) && wbc->sync_mode == WB_SYNC_NONE &&
+			get_dirty_dents(inode) < nr_pages_to_skip(sbi, DATA))
+		goto skip_write;
+
+	diff = nr_pages_to_write(sbi, DATA, wbc);
 
 	if (!S_ISDIR(inode->i_mode)) {
 		mutex_lock(&sbi->writepages);
···
 
 	remove_dirty_dir_inode(inode);
 
-	wbc->nr_to_write -= excess_nrtw;
+	wbc->nr_to_write = max((long)0, wbc->nr_to_write - diff);
 	return ret;
+
+skip_write:
+	wbc->pages_skipped += get_dirty_dents(inode);
+	return 0;
 }
 
 static int f2fs_write_begin(struct file *file, struct address_space *mapping,
···
 	if (dn.data_blkaddr == NEW_ADDR) {
 		zero_user_segment(page, 0, PAGE_CACHE_SIZE);
 	} else {
-		if (f2fs_has_inline_data(inode))
+		if (f2fs_has_inline_data(inode)) {
 			err = f2fs_read_inline_data(inode, page);
-		else
+			if (err) {
+				page_cache_release(page);
+				return err;
+			}
+		} else {
 			err = f2fs_submit_page_bio(sbi, page, dn.data_blkaddr,
 							READ_SYNC);
-		if (err)
-			return err;
+			if (err)
+				return err;
+		}
+
 		lock_page(page);
 		if (unlikely(!PageUptodate(page))) {
 			f2fs_put_page(page, 1);
···
 				      unsigned int length)
 {
 	struct inode *inode = page->mapping->host;
-	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
-	if (S_ISDIR(inode->i_mode) && PageDirty(page)) {
-		dec_page_count(sbi, F2FS_DIRTY_DENTS);
+	if (PageDirty(page))
 		inode_dec_dirty_dents(inode);
-	}
 	ClearPagePrivate(page);
 }
 

fs/f2fs/debug.c

···
 {
 	struct f2fs_stat_info *si = F2FS_STAT(sbi);
 	unsigned int blks_per_sec, hblks_per_sec, total_vblocks, bimodal, dist;
-	struct sit_info *sit_i = SIT_I(sbi);
 	unsigned int segno, vblocks;
 	int ndirty = 0;
 
···
 	total_vblocks = 0;
 	blks_per_sec = sbi->segs_per_sec * (1 << sbi->log_blocks_per_seg);
 	hblks_per_sec = blks_per_sec / 2;
-	mutex_lock(&sit_i->sentry_lock);
 	for (segno = 0; segno < TOTAL_SEGS(sbi); segno += sbi->segs_per_sec) {
 		vblocks = get_valid_blocks(sbi, segno, sbi->segs_per_sec);
 		dist = abs(vblocks - hblks_per_sec);
···
 			ndirty++;
 		}
 	}
-	mutex_unlock(&sit_i->sentry_lock);
 	dist = TOTAL_SECS(sbi) * hblks_per_sec * hblks_per_sec / 100;
 	si->bimodal = bimodal / dist;
 	if (si->dirty_count)
···
 			   si->dirty_count);
 		seq_printf(s, "  - Prefree: %d\n  - Free: %d (%d)\n\n",
 			   si->prefree_count, si->free_segs, si->free_secs);
+		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);
···
 			   si->ndirty_dent, si->ndirty_dirs);
 		seq_printf(s, "  - meta: %4d in %4d\n",
 			   si->ndirty_meta, si->meta_pages);
-		seq_printf(s, "  - NATs: %5d > %lu\n",
-			   si->nats, NM_WOUT_THRESHOLD);
-		seq_printf(s, "  - SITs: %5d\n  - free_nids: %5d\n",
-			   si->sits, si->fnids);
+		seq_printf(s, "  - NATs: %9d\n  - SITs: %9d\n",
+			   si->nats, si->sits);
+		seq_printf(s, "  - free_nids: %9d\n",
+			   si->fnids);
 		seq_puts(s, "\nDistribution of User Blocks:");
 		seq_puts(s, " [ valid | invalid | free ]\n");
 		seq_puts(s, "  [");

fs/f2fs/dir.c

···
 							>> PAGE_CACHE_SHIFT;
 }
 
-static unsigned int dir_buckets(unsigned int level)
+static unsigned int dir_buckets(unsigned int level, int dir_level)
 {
 	if (level < MAX_DIR_HASH_DEPTH / 2)
-		return 1 << level;
+		return 1 << (level + dir_level);
 	else
-		return 1 << ((MAX_DIR_HASH_DEPTH / 2) - 1);
+		return 1 << ((MAX_DIR_HASH_DEPTH / 2 + dir_level) - 1);
 }
 
 static unsigned int bucket_blocks(unsigned int level)
···
 	de->file_type = f2fs_type_by_mode[(mode & S_IFMT) >> S_SHIFT];
 }
 
-static unsigned long dir_block_index(unsigned int level, unsigned int idx)
+static unsigned long dir_block_index(unsigned int level,
+				int dir_level, unsigned int idx)
 {
 	unsigned long i;
 	unsigned long bidx = 0;
 
 	for (i = 0; i < level; i++)
-		bidx += dir_buckets(i) * bucket_blocks(i);
+		bidx += dir_buckets(i, dir_level) * bucket_blocks(i);
 	bidx += idx * bucket_blocks(level);
 	return bidx;
 }
···
 			f2fs_hash_t namehash, struct page **res_page)
 {
 	struct f2fs_dir_entry *de;
-	unsigned long bit_pos, end_pos, next_pos;
+	unsigned long bit_pos = 0;
 	struct f2fs_dentry_block *dentry_blk = kmap(dentry_page);
-	int slots;
+	const void *dentry_bits = &dentry_blk->dentry_bitmap;
+	int max_len = 0;
 
-	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
-					NR_DENTRY_IN_BLOCK, 0);
 	while (bit_pos < NR_DENTRY_IN_BLOCK) {
+		if (!test_bit_le(bit_pos, dentry_bits)) {
+			if (bit_pos == 0)
+				max_len = 1;
+			else if (!test_bit_le(bit_pos - 1, dentry_bits))
+				max_len++;
+			bit_pos++;
+			continue;
+		}
 		de = &dentry_blk->dentry[bit_pos];
-		slots = GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
-
 		if (early_match_name(name, namelen, namehash, de)) {
 			if (!memcmp(dentry_blk->filename[bit_pos],
 							name, namelen)) {
···
 				goto found;
 			}
 		}
-		next_pos = bit_pos + slots;
-		bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
-				NR_DENTRY_IN_BLOCK, next_pos);
-		if (bit_pos >= NR_DENTRY_IN_BLOCK)
-			end_pos = NR_DENTRY_IN_BLOCK;
-		else
-			end_pos = bit_pos;
-		if (*max_slots < end_pos - next_pos)
-			*max_slots = end_pos - next_pos;
+		if (max_len > *max_slots) {
+			*max_slots = max_len;
+			max_len = 0;
+		}
+		bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
 	}
 
 	de = NULL;
 	kunmap(dentry_page);
 found:
+	if (max_len > *max_slots)
+		*max_slots = max_len;
 	return de;
 }
 
···
 
 	f2fs_bug_on(level > MAX_DIR_HASH_DEPTH);
 
-	nbucket = dir_buckets(level);
+	nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
 	nblock = bucket_blocks(level);
 
-	bidx = dir_block_index(level, le32_to_cpu(namehash) % nbucket);
+	bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
+					le32_to_cpu(namehash) % nbucket);
 	end_block = bidx + nblock;
 
 	for (; bidx < end_block; bidx++) {
···
 		struct page *page, struct inode *inode)
 {
 	lock_page(page);
-	wait_on_page_writeback(page);
+	f2fs_wait_on_page_writeback(page, DATA);
 	de->ino = cpu_to_le32(inode->i_ino);
 	set_de_type(de, inode);
 	kunmap(page);
···
 		err = f2fs_init_security(inode, dir, name, page);
 		if (err)
 			goto put_error;
-
-		wait_on_page_writeback(page);
 	} else {
 		page = get_node_page(F2FS_SB(dir->i_sb), inode->i_ino);
 		if (IS_ERR(page))
 			return page;
 
-		wait_on_page_writeback(page);
 		set_cold_node(inode, page);
 	}
 
···
 
 put_error:
 	f2fs_put_page(page, 1);
+	/* once the failed inode becomes a bad inode, i_mode is S_IFREG */
+	truncate_inode_pages(&inode->i_data, 0);
+	truncate_blocks(inode, 0);
+	remove_dirty_dir_inode(inode);
 error:
 	remove_inode_page(inode);
 	return ERR_PTR(err);
···
 		F2FS_I(dir)->i_current_depth = current_depth;
 		set_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
 	}
-
-	if (is_inode_flag_set(F2FS_I(dir), FI_UPDATE_DIR))
-		update_inode_page(dir);
 
 	if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK))
 		clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
···
 	if (level == current_depth)
 		++current_depth;
 
-	nbucket = dir_buckets(level);
+	nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
 	nblock = bucket_blocks(level);
 
-	bidx = dir_block_index(level, (le32_to_cpu(dentry_hash) % nbucket));
+	bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
+				(le32_to_cpu(dentry_hash) % nbucket));
 
 	for (block = bidx; block <= (bidx + nblock - 1); block++) {
 		dentry_page = get_new_data_page(dir, NULL, block, true);
···
 	++level;
 	goto start;
 add_dentry:
-	wait_on_page_writeback(dentry_page);
+	f2fs_wait_on_page_writeback(dentry_page, DATA);
 
+	down_write(&F2FS_I(inode)->i_sem);
 	page = init_inode_metadata(inode, dir, name);
 	if (IS_ERR(page)) {
 		err = PTR_ERR(page);
···
 
 	update_parent_metadata(dir, inode, current_depth);
 fail:
-	clear_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
+	up_write(&F2FS_I(inode)->i_sem);
+
+	if (is_inode_flag_set(F2FS_I(dir), FI_UPDATE_DIR)) {
+		update_inode_page(dir);
+		clear_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
+	}
 	kunmap(dentry_page);
 	f2fs_put_page(dentry_page, 1);
 	return err;
···
 	unsigned int bit_pos;
 	struct address_space *mapping = page->mapping;
 	struct inode *dir = mapping->host;
-	struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
 	int slots = GET_DENTRY_SLOTS(le16_to_cpu(dentry->name_len));
 	void *kaddr = page_address(page);
 	int i;
 
 	lock_page(page);
-	wait_on_page_writeback(page);
+	f2fs_wait_on_page_writeback(page, DATA);
 
 	dentry_blk = (struct f2fs_dentry_block *)kaddr;
 	bit_pos = dentry - (struct f2fs_dir_entry *)dentry_blk->dentry;
···
 	dir->i_ctime = dir->i_mtime = CURRENT_TIME;
 
 	if (inode) {
+		struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
+
+		down_write(&F2FS_I(inode)->i_sem);
+
 		if (S_ISDIR(inode->i_mode)) {
 			drop_nlink(dir);
 			update_inode_page(dir);
···
 			drop_nlink(inode);
 			i_size_write(inode, 0);
 		}
+		up_write(&F2FS_I(inode)->i_sem);
 		update_inode_page(inode);
 
 		if (inode->i_nlink == 0)
···
 		truncate_hole(dir, page->index, page->index + 1);
 		clear_page_dirty_for_io(page);
 		ClearPageUptodate(page);
-		dec_page_count(sbi, F2FS_DIRTY_DENTS);
 		inode_dec_dirty_dents(dir);
 	}
 	f2fs_put_page(page, 1);

fs/f2fs/f2fs.h

···
 #define F2FS_MOUNT_DISABLE_EXT_IDENTIFY	0x00000040
 #define F2FS_MOUNT_INLINE_XATTR		0x00000080
 #define F2FS_MOUNT_INLINE_DATA		0x00000100
+#define F2FS_MOUNT_FLUSH_MERGE		0x00000200
 
 #define clear_opt(sbi, option)	(sbi->mount_opt.opt &= ~F2FS_MOUNT_##option)
 #define set_opt(sbi, option)	(sbi->mount_opt.opt |= F2FS_MOUNT_##option)
···
 enum {
 	NAT_BITMAP,
 	SIT_BITMAP
+};
+
+/*
+ * For CP/NAT/SIT/SSA readahead
+ */
+enum {
+	META_CP,
+	META_NAT,
+	META_SIT,
+	META_SSA
 };
 
 /* for the list of orphan inodes */
···
 #define FADVISE_COLD_BIT	0x01
 #define FADVISE_LOST_PINO_BIT	0x02
 
+#define DEF_DIR_LEVEL		0
+
 struct f2fs_inode_info {
 	struct inode vfs_inode;		/* serve a vfs inode */
 	unsigned long i_flags;		/* keep an inode flags for ioctl */
 	unsigned char i_advise;		/* use to give file attribute hints */
+	unsigned char i_dir_level;	/* use for dentry level for large dir */
 	unsigned int i_current_depth;	/* use only in directory structure */
 	unsigned int i_pino;		/* parent inode number */
 	umode_t i_acl_mode;		/* keep file acl mode temporarily */
 
 	/* Use below internally in f2fs*/
 	unsigned long flags;		/* use to pass per-file flags */
+	struct rw_semaphore i_sem;	/* protect fi info */
 	atomic_t dirty_dents;		/* # of dirty dentry pages */
 	f2fs_hash_t chash;		/* hash value of given file name */
 	unsigned int clevel;		/* maximum level of given file name */
···
 	block_t nat_blkaddr;		/* base disk address of NAT */
 	nid_t max_nid;			/* maximum possible node ids */
 	nid_t next_scan_nid;		/* the next nid to be scanned */
+	unsigned int ram_thresh;	/* control the memory footprint */
 
 	/* NAT cache management */
 	struct radix_tree_root nat_root;/* root of the nat entry cache */
···
 	struct list_head dirty_nat_entries; /* cached nat entry list (dirty) */
 
 	/* free node ids management */
+	struct radix_tree_root free_nid_root;/* root of the free_nid cache */
 	struct list_head free_nid_list;	/* a list for free nids */
 	spinlock_t free_nid_list_lock;	/* protect free nid list */
 	unsigned int fcnt;		/* the number of free node id */
···
 	NO_CHECK_TYPE
 };
 
+struct flush_cmd {
+	struct flush_cmd *next;
+	struct completion wait;
+	int ret;
+};
+
 struct f2fs_sm_info {
 	struct sit_info *sit_info;		/* whole segment information */
 	struct free_segmap_info *free_info;	/* free segment information */
···
 
 	unsigned int ipu_policy;	/* in-place-update policy */
 	unsigned int min_ipu_util;	/* in-place-update threshold */
+
+	/* for flush command control */
+	struct task_struct *f2fs_issue_flush;	/* flush thread */
+	wait_queue_head_t flush_wait_queue;	/* waiting queue for wake-up */
+	struct flush_cmd *issue_list;		/* list for command issue */
+	struct flush_cmd *dispatch_list;	/* list for command dispatch */
+	spinlock_t issue_lock;			/* for issue list lock */
+	struct flush_cmd *issue_tail;		/* list tail of issue list */
 };
 
 /*
···
 	struct bio *bio;		/* bios to merge */
 	sector_t last_block_in_bio;	/* last block number */
 	struct f2fs_io_info fio;	/* store buffered io info. */
-	struct mutex io_mutex;		/* mutex for bio */
+	struct rw_semaphore io_rwsem;	/* blocking op for bio */
 };
 
 struct f2fs_sb_info {
···
 	/* for bio operations */
 	struct f2fs_bio_info read_io;			/* for read bios */
 	struct f2fs_bio_info write_io[NR_PAGE_TYPE];	/* for write bios */
+	struct completion *wait_io;		/* for completion bios */
 
 	/* for checkpoint */
 	struct f2fs_checkpoint *ckpt;		/* raw checkpoint pointer */
···
 	struct mutex node_write;		/* locking node writes */
 	struct mutex writepages;		/* mutex for writepages() */
 	bool por_doing;				/* recovery is doing or not */
-	bool on_build_free_nids;		/* build_free_nids is doing */
 	wait_queue_head_t cp_wait;
 
 	/* for orphan inode management */
···
 	unsigned int total_valid_node_count;	/* valid node block count */
 	unsigned int total_valid_inode_count;	/* valid inode count */
 	int active_logs;			/* # of active logs */
+	int dir_level;				/* directory level */
 
 	block_t user_block_count;		/* # of user blocks */
 	block_t total_valid_block_count;	/* # of valid blocks */
···
 		return inode->i_blocks > F2FS_DEFAULT_ALLOCATED_BLOCKS;
 }
 
+static inline bool f2fs_has_xattr_block(unsigned int ofs)
+{
+	return ofs == XATTR_NODE_OFFSET;
+}
+
 static inline bool inc_valid_block_count(struct f2fs_sb_info *sbi,
 				 struct inode *inode, blkcnt_t count)
 {
···
 
 static inline void inode_inc_dirty_dents(struct inode *inode)
 {
+	inc_page_count(F2FS_SB(inode->i_sb), F2FS_DIRTY_DENTS);
 	atomic_inc(&F2FS_I(inode)->dirty_dents);
 }
 
···
 
 static inline void inode_dec_dirty_dents(struct inode *inode)
 {
+	if (!S_ISDIR(inode->i_mode))
+		return;
+
+	dec_page_count(F2FS_SB(inode->i_sb), F2FS_DIRTY_DENTS);
 	atomic_dec(&F2FS_I(inode)->dirty_dents);
 }
 
 static inline int get_pages(struct f2fs_sb_info *sbi, int count_type)
 {
 	return atomic_read(&sbi->nr_pages[count_type]);
+}
+
+static inline int get_dirty_dents(struct inode *inode)
+{
+	return atomic_read(&F2FS_I(inode)->dirty_dents);
 }
 
 static inline int get_blocktype_secs(struct f2fs_sb_info *sbi, int block_type)
···
 
 static inline block_t valid_user_blocks(struct f2fs_sb_info *sbi)
 {
-	block_t ret;
-	spin_lock(&sbi->stat_lock);
-	ret = sbi->total_valid_block_count;
-	spin_unlock(&sbi->stat_lock);
-	return ret;
+	return sbi->total_valid_block_count;
 }
 
 static inline unsigned long __bitmap_size(struct f2fs_sb_info *sbi, int flag)
···
 
 static inline unsigned int valid_node_count(struct f2fs_sb_info *sbi)
 {
-	unsigned int ret;
-	spin_lock(&sbi->stat_lock);
-	ret = sbi->total_valid_node_count;
-	spin_unlock(&sbi->stat_lock);
-	return ret;
+	return sbi->total_valid_node_count;
 }
 
 static inline void inc_valid_inode_count(struct f2fs_sb_info *sbi)
···
 
 static inline unsigned int valid_inode_count(struct f2fs_sb_info *sbi)
 {
-	unsigned int ret;
-	spin_lock(&sbi->stat_lock);
-	ret = sbi->total_valid_inode_count;
-	spin_unlock(&sbi->stat_lock);
-	return ret;
+	return sbi->total_valid_inode_count;
 }
 
 static inline void f2fs_put_page(struct page *page, int unlock)
···
 }
 
 static inline struct kmem_cache *f2fs_kmem_cache_create(const char *name,
-					size_t size, void (*ctor)(void *))
+					size_t size)
 {
-	return kmem_cache_create(name, size, 0, SLAB_RECLAIM_ACCOUNT, ctor);
+	return kmem_cache_create(name, size, 0, SLAB_RECLAIM_ACCOUNT, NULL);
 }
 
 static inline void *f2fs_kmem_cache_alloc(struct kmem_cache *cachep,
···
 		ri->i_inline |= F2FS_INLINE_DATA;
 }
 
+static inline int f2fs_has_inline_xattr(struct inode *inode)
+{
+	return is_inode_flag_set(F2FS_I(inode), FI_INLINE_XATTR);
+}
+
 static inline unsigned int addrs_per_inode(struct f2fs_inode_info *fi)
 {
-	if (is_inode_flag_set(fi, FI_INLINE_XATTR))
+	if (f2fs_has_inline_xattr(&fi->vfs_inode))
 		return DEF_ADDRS_PER_INODE - F2FS_INLINE_XATTR_ADDRS;
 	return DEF_ADDRS_PER_INODE;
 }
 
 static inline void *inline_xattr_addr(struct page *page)
 {
-	struct f2fs_inode *ri;
-	ri = (struct f2fs_inode *)page_address(page);
+	struct f2fs_inode *ri = F2FS_INODE(page);
 	return (void *)&(ri->i_addr[DEF_ADDRS_PER_INODE -
 					F2FS_INLINE_XATTR_ADDRS]);
 }
 
 static inline int inline_xattr_size(struct inode *inode)
 {
-	if (is_inode_flag_set(F2FS_I(inode), FI_INLINE_XATTR))
+	if (f2fs_has_inline_xattr(inode))
 		return F2FS_INLINE_XATTR_ADDRS << 2;
 	else
 		return 0;
···
 
 static inline void *inline_data_addr(struct page *page)
 {
-	struct f2fs_inode *ri;
-	ri = (struct f2fs_inode *)page_address(page);
+	struct f2fs_inode *ri = F2FS_INODE(page);
 	return (void *)&(ri->i_addr[1]);
 }
 
 static inline int f2fs_readonly(struct super_block *sb)
 {
 	return sb->s_flags & MS_RDONLY;
+}
+
+static inline void f2fs_stop_checkpoint(struct f2fs_sb_info *sbi)
+{
+	set_ckpt_flags(sbi->ckpt, CP_ERROR_FLAG);
+	sbi->sb->s_flags |= MS_RDONLY;
 }
 
 #define get_inode_mode(i) \
···
 struct inode *f2fs_iget(struct super_block *, unsigned long);
 int try_to_free_nats(struct f2fs_sb_info *, int);
 void update_inode(struct inode *, struct page *);
-int update_inode_page(struct inode *);
+void update_inode_page(struct inode *);
 int f2fs_write_inode(struct inode *, struct writeback_control *);
 void f2fs_evict_inode(struct inode *);
 
···
 struct node_info;
 
 int is_checkpointed_node(struct f2fs_sb_info *, nid_t);
+bool fsync_mark_done(struct f2fs_sb_info *, nid_t);
 void get_node_info(struct f2fs_sb_info *, nid_t, struct node_info *);
 int get_dnode_of_data(struct dnode_of_data *, pgoff_t, int);
 int truncate_inode_blocks(struct inode *, pgoff_t);
···
 void alloc_nid_failed(struct f2fs_sb_info *, nid_t);
 void recover_node_page(struct f2fs_sb_info *, struct page *,
 		struct f2fs_summary *, struct node_info *, block_t);
+bool recover_xattr_data(struct inode *, struct page *, block_t);
 int recover_inode_page(struct f2fs_sb_info *, struct page *);
 int restore_node_summary(struct f2fs_sb_info *, unsigned int,
 				struct f2fs_summary_block *);
···
  */
 void f2fs_balance_fs(struct f2fs_sb_info *);
 void f2fs_balance_fs_bg(struct f2fs_sb_info *);
+int f2fs_issue_flush(struct f2fs_sb_info *);
 void invalidate_blocks(struct f2fs_sb_info *, block_t);
+void refresh_sit_entry(struct f2fs_sb_info *, block_t, block_t);
 void clear_prefree_segments(struct f2fs_sb_info *);
 int npages_for_summary_flush(struct f2fs_sb_info *);
 void allocate_new_segments(struct f2fs_sb_info *);
···
  */
 struct page *grab_meta_page(struct f2fs_sb_info *, pgoff_t);
 struct page *get_meta_page(struct f2fs_sb_info *, pgoff_t);
+int ra_meta_pages(struct f2fs_sb_info *, int, int, int);
 long sync_meta_pages(struct f2fs_sb_info *, enum page_type, long);
 int acquire_orphan_inode(struct f2fs_sb_info *);
 void release_orphan_inode(struct f2fs_sb_info *);
···
 	int util_free, util_valid, util_invalid;
 	int rsvd_segs, overp_segs;
 	int dirty_count, node_pages, meta_pages;
-	int prefree_count, call_count;
+	int prefree_count, call_count, cp_count;
 	int tot_segs, node_segs, data_segs, free_segs, free_secs;
 	int tot_blks, data_blks, node_blks;
 	int curseg[NR_CURSEG_TYPE];
···
 	return (struct f2fs_stat_info *)sbi->stat_info;
 }
 
+#define stat_inc_cp_count(si)		((si)->cp_count++)
 #define stat_inc_call_count(si)		((si)->call_count++)
 #define stat_inc_bggc_count(sbi)	((sbi)->bg_gc++)
 #define stat_inc_dirty_dir(sbi)		((sbi)->n_dirty_dirs++)
···
 void __init f2fs_create_root_stats(void);
 void f2fs_destroy_root_stats(void);
 #else
+#define stat_inc_cp_count(si)
 #define stat_inc_call_count(si)
 #define stat_inc_bggc_count(si)
 #define stat_inc_dirty_dir(sbi)

fs/f2fs/file.c

···
 	trace_f2fs_vm_page_mkwrite(page, DATA);
 mapped:
 	/* fill the page */
-	wait_on_page_writeback(page);
+	f2fs_wait_on_page_writeback(page, DATA);
 out:
 	sb_end_pagefault(inode->i_sb);
 	return block_page_mkwrite_return(err);
···
 int f2fs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
 {
 	struct inode *inode = file->f_mapping->host;
+	struct f2fs_inode_info *fi = F2FS_I(inode);
 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 	int ret = 0;
 	bool need_cp = false;
 	struct writeback_control wbc = {
-		.sync_mode = WB_SYNC_NONE,
+		.sync_mode = WB_SYNC_ALL,
 		.nr_to_write = LONG_MAX,
 		.for_reclaim = 0,
 	};
···
 	/* guarantee free sections for fsync */
 	f2fs_balance_fs(sbi);
 
-	mutex_lock(&inode->i_mutex);
+	down_read(&fi->i_sem);
 
 	/*
 	 * Both of fdatasync() and fsync() are able to be recovered from
···
 	else if (F2FS_I(inode)->xattr_ver == cur_cp_version(F2FS_CKPT(sbi)))
 		need_cp = true;
 
+	up_read(&fi->i_sem);
+
 	if (need_cp) {
 		nid_t pino;
 
-		F2FS_I(inode)->xattr_ver = 0;
-
 		/* all the dirty node pages should be flushed for POR */
 		ret = f2fs_sync_fs(inode->i_sb, 1);
+
+		down_write(&fi->i_sem);
+		F2FS_I(inode)->xattr_ver = 0;
 		if (file_wrong_pino(inode) && inode->i_nlink == 1 &&
 					get_parent_ino(inode, &pino)) {
 			F2FS_I(inode)->i_pino = pino;
 			file_got_pino(inode);
+			up_write(&fi->i_sem);
 			mark_inode_dirty_sync(inode);
 			ret = f2fs_write_inode(inode, NULL);
 			if (ret)
 				goto out;
+		} else {
+			up_write(&fi->i_sem);
 		}
 	} else {
 		/* if there is no written node page, write its inode page */
 		while (!sync_node_pages(sbi, inode->i_ino, &wbc)) {
+			if (fsync_mark_done(sbi, inode->i_ino))
+				goto out;
 			mark_inode_dirty_sync(inode);
 			ret = f2fs_write_inode(inode, NULL);
 			if (ret)
···
 		ret = wait_on_node_pages_writeback(sbi, inode->i_ino);
 		if (ret)
 			goto out;
-		ret = blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
+		ret = f2fs_issue_flush(F2FS_SB(inode->i_sb));
 	}
 out:
-	mutex_unlock(&inode->i_mutex);
 	trace_f2fs_sync_file_exit(inode, need_cp, datasync, ret);
 	return ret;
 }
···
 		f2fs_put_page(page, 1);
 		return;
 	}
-	wait_on_page_writeback(page);
+	f2fs_wait_on_page_writeback(page, DATA);
 	zero_user(page, offset, PAGE_CACHE_SIZE - offset);
 	set_page_dirty(page);
 	f2fs_put_page(page, 1);
···
 	f2fs_unlock_op(sbi);
 
 	if (!IS_ERR(page)) {
-		wait_on_page_writeback(page);
+		f2fs_wait_on_page_writeback(page, DATA);
 		zero_user(page, start, len);
 		set_page_dirty(page);
 		f2fs_put_page(page, 1);
···
 	if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
 		return -EOPNOTSUPP;
 
+	mutex_lock(&inode->i_mutex);
+
 	if (mode & FALLOC_FL_PUNCH_HOLE)
 		ret = punch_hole(inode, offset, len);
 	else
···
 		inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 		mark_inode_dirty(inode);
 	}
+
+	mutex_unlock(&inode->i_mutex);
+
 	trace_f2fs_fallocate(inode, mode, offset, len, ret);
 	return ret;
 }

fs/f2fs/gc.c

···
 		set_page_dirty(page);
 		set_cold_data(page);
 	} else {
-		struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
-
 		f2fs_wait_on_page_writeback(page, DATA);
 
-		if (clear_page_dirty_for_io(page) &&
-			S_ISDIR(inode->i_mode)) {
-			dec_page_count(sbi, F2FS_DIRTY_DENTS);
+		if (clear_page_dirty_for_io(page))
 			inode_dec_dirty_dents(inode);
-		}
 		set_cold_data(page);
 		do_write_data_page(page, &fio);
 		clear_cold_data(page);
···
 gc_more:
 	if (unlikely(!(sbi->sb->s_flags & MS_ACTIVE)))
 		goto stop;
+	if (unlikely(is_set_ckpt_flags(F2FS_CKPT(sbi), CP_ERROR_FLAG)))
+		goto stop;
 
 	if (gc_type == BG_GC && has_not_enough_free_secs(sbi, nfree)) {
 		gc_type = FG_GC;
···
 	if (!__get_victim(sbi, &segno, gc_type, NO_CHECK_TYPE))
 		goto stop;
 	ret = 0;
+
+	/* readahead multi ssa blocks those have contiguous address */
+	if (sbi->segs_per_sec > 1)
+		ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno), sbi->segs_per_sec,
+								META_SSA);
 
 	for (i = 0; i < sbi->segs_per_sec; i++)
 		do_garbage_collect(sbi, segno + i, &ilist, gc_type);
···
 int __init create_gc_caches(void)
 {
 	winode_slab = f2fs_kmem_cache_create("f2fs_gc_inodes",
-			sizeof(struct inode_entry), NULL);
+			sizeof(struct inode_entry));
 	if (!winode_slab)
 		return -ENOMEM;
 	return 0;

fs/f2fs/inline.c

···
 	}
 
 	ipage = get_node_page(sbi, inode->i_ino);
-	if (IS_ERR(ipage))
+	if (IS_ERR(ipage)) {
+		unlock_page(page);
 		return PTR_ERR(ipage);
+	}
 
 	zero_user_segment(page, MAX_INLINE_DATA, PAGE_CACHE_SIZE);
 

fs/f2fs/inode.c

···
 	fi->flags = 0;
 	fi->i_advise = ri->i_advise;
 	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);
 	get_inline_info(fi, ri);
···
 	ri->i_flags = cpu_to_le32(F2FS_I(inode)->i_flags);
 	ri->i_pino = cpu_to_le32(F2FS_I(inode)->i_pino);
 	ri->i_generation = cpu_to_le32(inode->i_generation);
+	ri->i_dir_level = F2FS_I(inode)->i_dir_level;
 
 	__set_inode_rdev(inode, ri);
 	set_cold_node(inode, node_page);
···
 	clear_inode_flag(F2FS_I(inode), FI_DIRTY_INODE);
 }
 
-int update_inode_page(struct inode *inode)
+void update_inode_page(struct inode *inode)
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 	struct page *node_page;
-
+retry:
 	node_page = get_node_page(sbi, inode->i_ino);
-	if (IS_ERR(node_page))
-		return PTR_ERR(node_page);
-
+	if (IS_ERR(node_page)) {
+		int err = PTR_ERR(node_page);
+		if (err == -ENOMEM) {
+			cond_resched();
+			goto retry;
+		} else if (err != -ENOENT) {
+			f2fs_stop_checkpoint(sbi);
+		}
+		return;
+	}
 	update_inode(inode, node_page);
 	f2fs_put_page(node_page, 1);
-	return 0;
 }
 
 int f2fs_write_inode(struct inode *inode, struct writeback_control *wbc)
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
-	int ret;
 
 	if (inode->i_ino == F2FS_NODE_INO(sbi) ||
 			inode->i_ino == F2FS_META_INO(sbi))
···
 	 * during the urgent cleaning time when runing out of free sections.
 	 */
 	f2fs_lock_op(sbi);
-	ret = update_inode_page(inode);
+	update_inode_page(inode);
 	f2fs_unlock_op(sbi);
 
 	if (wbc)
 		f2fs_balance_fs(sbi);
 
-	return ret;
+	return 0;
 }
 
 /*
···
 			inode->i_ino == F2FS_META_INO(sbi))
 		goto no_delete;
 
-	f2fs_bug_on(atomic_read(&F2FS_I(inode)->dirty_dents));
+	f2fs_bug_on(get_dirty_dents(inode));
 	remove_dirty_dir_inode(inode);
 
 	if (inode->i_nlink || is_bad_inode(inode))

fs/f2fs/namei.c

···
 		inode = f2fs_iget(dir->i_sb, ino);
 		if (IS_ERR(inode))
 			return ERR_CAST(inode);
+
+		stat_inc_inline_inode(inode);
 	}
 
 	return d_splice_alias(inode, dentry);
···
 		}
 
 		f2fs_set_link(new_dir, new_entry, new_page, old_inode);
+		down_write(&F2FS_I(old_inode)->i_sem);
 		F2FS_I(old_inode)->i_pino = new_dir->i_ino;
+		up_write(&F2FS_I(old_inode)->i_sem);
 
 		new_inode->i_ctime = CURRENT_TIME;
+		down_write(&F2FS_I(new_inode)->i_sem);
 		if (old_dir_entry)
 			drop_nlink(new_inode);
 		drop_nlink(new_inode);
+		up_write(&F2FS_I(new_inode)->i_sem);
+
 		mark_inode_dirty(new_inode);
 
 		if (!new_inode->i_nlink)
···
 		if (old_dir != new_dir) {
 			f2fs_set_link(old_inode, old_dir_entry,
 						old_dir_page, new_dir);
+			down_write(&F2FS_I(old_inode)->i_sem);
 			F2FS_I(old_inode)->i_pino = new_dir->i_ino;
+			up_write(&F2FS_I(old_inode)->i_sem);
 			update_inode_page(old_inode);
 		} else {
 			kunmap(old_dir_page);

fs/f2fs/node.c

···
 #include "segment.h"
 #include <trace/events/f2fs.h>
 
+#define on_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 inline bool available_free_memory(struct f2fs_nm_info *nm_i, int type)
+{
+	struct sysinfo val;
+	unsigned long mem_size = 0;
+
+	si_meminfo(&val);
+	if (type == FREE_NIDS)
+		mem_size = nm_i->fcnt * sizeof(struct free_nid);
+	else if (type == NAT_ENTRIES)
+		mem_size += nm_i->nat_cnt * sizeof(struct nat_entry);
+	mem_size >>= 12;
+
+	/* give 50:50 memory for free nids and nat caches respectively */
+	return (mem_size < ((val.totalram * nm_i->ram_thresh) >> 11));
+}
 
 static void clear_node_page_dirty(struct page *page)
 {
···
 	return dst_page;
 }
 
-/*
- * Readahead NAT pages
- */
-static void ra_nat_pages(struct f2fs_sb_info *sbi, int nid)
-{
-	struct address_space *mapping = META_MAPPING(sbi);
-	struct f2fs_nm_info *nm_i = NM_I(sbi);
-	struct page *page;
-	pgoff_t index;
-	int i;
-	struct f2fs_io_info fio = {
-		.type = META,
-		.rw = READ_SYNC | REQ_META | REQ_PRIO
-	};
-
-
-	for (i = 0; i < FREE_NID_PAGES; i++, nid += NAT_ENTRY_PER_BLOCK) {
-		if (unlikely(nid >= nm_i->max_nid))
-			nid = 0;
-		index = current_nat_addr(sbi, nid);
-
-		page = grab_cache_page(mapping, index);
-		if (!page)
-			continue;
-		if (PageUptodate(page)) {
-			mark_page_accessed(page);
-			f2fs_put_page(page, 1);
-			continue;
-		}
-		f2fs_submit_page_mbio(sbi, page, index, &fio);
-		mark_page_accessed(page);
-		f2fs_put_page(page, 0);
-	}
-	f2fs_submit_merged_bio(sbi, META, READ);
-}
-
 static struct nat_entry *__lookup_nat_cache(struct f2fs_nm_info *nm_i, nid_t n)
 {
 	return radix_tree_lookup(&nm_i->nat_root, n);
···
 	return is_cp;
 }
 
+bool fsync_mark_done(struct f2fs_sb_info *sbi, nid_t nid)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct nat_entry *e;
+	bool fsync_done = false;
+
+	read_lock(&nm_i->nat_tree_lock);
+	e = __lookup_nat_cache(nm_i, nid);
+	if (e)
+		fsync_done = e->fsync_done;
+	read_unlock(&nm_i->nat_tree_lock);
+	return fsync_done;
+}
+
 static struct nat_entry *grab_nat_entry(struct f2fs_nm_info *nm_i, nid_t nid)
 {
 	struct nat_entry *new;
···
 	}
 	memset(new, 0, sizeof(struct nat_entry));
 	nat_set_nid(new, nid);
+	new->checkpointed = true;
 	list_add_tail(&new->list, &nm_i->nat_entries);
 	nm_i->nat_cnt++;
 	return new;
···
 		nat_set_blkaddr(e, le32_to_cpu(ne->block_addr));
 		nat_set_ino(e, le32_to_cpu(ne->ino));
 		nat_set_version(e, ne->version);
-		e->checkpointed = true;
 	}
 	write_unlock(&nm_i->nat_tree_lock);
 }
 
 static void set_node_addr(struct f2fs_sb_info *sbi, struct node_info *ni,
-			block_t new_blkaddr)
+			block_t new_blkaddr, bool fsync_done)
 {
 	struct f2fs_nm_info *nm_i = NM_I(sbi);
 	struct nat_entry *e;
···
 			goto retry;
 		}
 		e->ni = *ni;
-		e->checkpointed = true;
 		f2fs_bug_on(ni->blk_addr == NEW_ADDR);
 	} else if (new_blkaddr == NEW_ADDR) {
 		/*
···
 		e->ni = *ni;
 		f2fs_bug_on(ni->blk_addr != NULL_ADDR);
 	}
-
-	if (new_blkaddr == NEW_ADDR)
-		e->checkpointed = false;
 
 	/* sanity check */
 	f2fs_bug_on(nat_get_blkaddr(e) != ni->blk_addr);
···
 	/* change address */
 	nat_set_blkaddr(e, new_blkaddr);
 	__set_nat_cache_dirty(nm_i, e);
+
+	/* update fsync_mark if its inode nat entry is still alive */
+	e = __lookup_nat_cache(nm_i, ni->ino);
+	if (e)
+		e->fsync_done = fsync_done;
 	write_unlock(&nm_i->nat_tree_lock);
 }
 
···
 {
 	struct f2fs_nm_info *nm_i = NM_I(sbi);
 
-	if (nm_i->nat_cnt <= NM_WOUT_THRESHOLD)
+	if (available_free_memory(nm_i, NAT_ENTRIES))
 		return 0;
 
 	write_lock(&nm_i->nat_tree_lock);
···
 	/* Deallocate node address */
 	invalidate_blocks(sbi, ni.blk_addr);
 	dec_valid_node_count(sbi, dn->inode);
-	set_node_addr(sbi, &ni, NULL_ADDR);
+	set_node_addr(sbi, &ni, NULL_ADDR, false);
 
 	if (dn->nid == dn->inode->i_ino) {
 		remove_orphan_inode(sbi, dn->nid);
···
 				f2fs_put_page(page, 1);
 				goto restart;
 			}
-			wait_on_page_writeback(page);
+			f2fs_wait_on_page_writeback(page, NODE);
 			ri->i_nid[offset[0] - NODE_DIR1_BLOCK] = 0;
 			set_page_dirty(page);
 			unlock_page(page);
···
 	if (unlikely(is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC)))
 		return ERR_PTR(-EPERM);
 
-	page = grab_cache_page(NODE_MAPPING(sbi), dn->nid);
+	page = grab_cache_page_write_begin(NODE_MAPPING(sbi),
+					dn->nid, AOP_FLAG_NOFS);
 	if (!page)
 		return ERR_PTR(-ENOMEM);
 
···
 	f2fs_bug_on(old_ni.blk_addr != NULL_ADDR);
 	new_ni = old_ni;
 	new_ni.ino = dn->inode->i_ino;
-	set_node_addr(sbi, &new_ni, NEW_ADDR);
+	set_node_addr(sbi, &new_ni, NEW_ADDR, false);
 
 	fill_node_footer(page, dn->nid, dn->inode->i_ino, ofs, true);
 	set_cold_node(dn->inode, page);
 	SetPageUptodate(page);
 	set_page_dirty(page);
 
-	if (ofs == XATTR_NODE_OFFSET)
+	if (f2fs_has_xattr_block(ofs))
 		F2FS_I(dn->inode)->i_xattr_nid = dn->nid;
 
 	dn->node_page = page;
···
 	struct page *page;
 	int err;
 repeat:
-	page = grab_cache_page(NODE_MAPPING(sbi), nid);
+	page = grab_cache_page_write_begin(NODE_MAPPING(sbi),
+					nid, AOP_FLAG_NOFS);
 	if (!page)
 		return ERR_PTR(-ENOMEM);
 
···
 		goto got_it;
 
 	lock_page(page);
-	if (unlikely(!PageUptodate(page))) {
+	if (unlikely(!PageUptodate(page) || nid != nid_of_node(page))) {
 		f2fs_put_page(page, 1);
 		return ERR_PTR(-EIO);
 	}
···
 		goto repeat;
 	}
 got_it:
-	f2fs_bug_on(nid != nid_of_node(page));
 	mark_page_accessed(page);
 	return page;
 }
···
 				continue;
 
 			if (ino && ino_of_node(page) == ino) {
-				wait_on_page_writeback(page);
+				f2fs_wait_on_page_writeback(page, NODE);
 				if (TestClearPageError(page))
 					ret = -EIO;
 			}
···
 	if (unlikely(sbi->por_doing))
 		goto redirty_out;
 
-	wait_on_page_writeback(page);
+	f2fs_wait_on_page_writeback(page, NODE);
 
 	/* get old block addr of this node page */
 	nid = nid_of_node(page);
···
 	mutex_lock(&sbi->node_write);
 	set_page_writeback(page);
 	write_node_page(sbi, page, &fio, nid, ni.blk_addr, &new_addr);
-	set_node_addr(sbi, &ni, new_addr);
+	set_node_addr(sbi, &ni, new_addr, is_fsync_dnode(page));
 	dec_page_count(sbi, F2FS_DIRTY_NODES);
 	mutex_unlock(&sbi->node_write);
 	unlock_page(page);
···
 redirty_out:
 	dec_page_count(sbi, F2FS_DIRTY_NODES);
 	wbc->pages_skipped++;
+	account_page_redirty(page);
 	set_page_dirty(page);
 	return AOP_WRITEPAGE_ACTIVATE;
 }
 
-/*
- * It is very important to gather dirty pages and write at once, so that we can
- * submit a big bio without interfering other data writes.
- * Be default, 512 pages (2MB) * 3 node types, is more reasonable.
- */
-#define COLLECT_DIRTY_NODES	1536
 static int f2fs_write_node_pages(struct address_space *mapping,
 			    struct writeback_control *wbc)
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(mapping->host->i_sb);
-	long nr_to_write = wbc->nr_to_write;
+	long diff;
 
 	/* balancing f2fs's metadata in background */
 	f2fs_balance_fs_bg(sbi);
 
 	/* collect a number of dirty node pages and write together */
-	if (get_pages(sbi, F2FS_DIRTY_NODES) < COLLECT_DIRTY_NODES)
-		return 0;
+	if (get_pages(sbi, F2FS_DIRTY_NODES) < nr_pages_to_skip(sbi, NODE))
+		goto skip_write;
 
-	/* if mounting is failed, skip writing node pages */
-	wbc->nr_to_write = 3 * max_hw_blocks(sbi);
+	diff = nr_pages_to_write(sbi, NODE, wbc);
 	wbc->sync_mode = WB_SYNC_NONE;
 	sync_node_pages(sbi, 0, wbc);
-	wbc->nr_to_write = nr_to_write - (3 * max_hw_blocks(sbi) -
-						wbc->nr_to_write);
+	wbc->nr_to_write = max((long)0, wbc->nr_to_write - diff);
+	return 0;
+
+skip_write:
+	wbc->pages_skipped += get_pages(sbi, F2FS_DIRTY_NODES);
 	return 0;
 }
 
···
 	.releasepage	= f2fs_release_node_page,
 };
 
-static struct free_nid *__lookup_free_nid_list(nid_t n, struct list_head *head)
+static struct free_nid *__lookup_free_nid_list(struct f2fs_nm_info *nm_i,
+						nid_t n)
 {
-	struct list_head *this;
-	struct free_nid *i;
-	list_for_each(this, head) {
-		i = list_entry(this, struct free_nid, list);
-		if (i->nid == n)
-			return i;
-	}
-	return NULL;
+	return radix_tree_lookup(&nm_i->free_nid_root, n);
 }
 
-static void __del_from_free_nid_list(struct free_nid *i)
+static void __del_from_free_nid_list(struct f2fs_nm_info *nm_i,
+						struct free_nid *i)
 {
 	list_del(&i->list);
-	kmem_cache_free(free_nid_slab, i);
+	radix_tree_delete(&nm_i->free_nid_root, i->nid);
 }
 
 static int add_free_nid(struct f2fs_nm_info *nm_i, nid_t nid, bool build)
···
 	struct nat_entry *ne;
 	bool allocated = false;
 
-	if (nm_i->fcnt > 2 * MAX_FREE_NIDS)
+	if (!available_free_memory(nm_i, FREE_NIDS))
 		return -1;
 
 	/* 0 nid should not be used */
···
 		/* do not add allocated nids */
 		read_lock(&nm_i->nat_tree_lock);
 		ne = __lookup_nat_cache(nm_i, nid);
-		if (ne && nat_get_blkaddr(ne) != NULL_ADDR)
+		if (ne &&
+			(!ne->checkpointed || nat_get_blkaddr(ne) != NULL_ADDR))
 			allocated = true;
 		read_unlock(&nm_i->nat_tree_lock);
 		if (allocated)
···
 	i->state = NID_NEW;
 
 	spin_lock(&nm_i->free_nid_list_lock);
-	if (__lookup_free_nid_list(nid, &nm_i->free_nid_list)) {
+	if (radix_tree_insert(&nm_i->free_nid_root, i->nid, i)) {
 		spin_unlock(&nm_i->free_nid_list_lock);
 		kmem_cache_free(free_nid_slab, i);
 		return 0;
···
 static void remove_free_nid(struct f2fs_nm_info *nm_i, nid_t nid)
 {
 	struct free_nid *i;
+	bool need_free = false;
+
 	spin_lock(&nm_i->free_nid_list_lock);
-	i = __lookup_free_nid_list(nid, &nm_i->free_nid_list);
+	i = __lookup_free_nid_list(nm_i, nid);
 	if (i && i->state == NID_NEW) {
-		__del_from_free_nid_list(i);
+		__del_from_free_nid_list(nm_i, i);
 		nm_i->fcnt--;
+		need_free = true;
 	}
 	spin_unlock(&nm_i->free_nid_list_lock);
+
+	if (need_free)
+		kmem_cache_free(free_nid_slab, i);
 }
 
 static void scan_nat_page(struct f2fs_nm_info *nm_i,
···
 		return;
 
 	/* readahead nat pages to be scanned */
-	ra_nat_pages(sbi, nid);
+	ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), FREE_NID_PAGES, META_NAT);
 
 	while (1) {
 		struct page *page = get_current_nat_page(sbi, nid);
···
 {
 	struct f2fs_nm_info *nm_i = NM_I(sbi);
 	struct free_nid *i = NULL;
-	struct list_head *this;
 retry:
 	if (unlikely(sbi->total_valid_node_count + 1 >= nm_i->max_nid))
 		return false;
···
 	spin_lock(&nm_i->free_nid_list_lock);
 
 	/* We should not use stale free nids created by build_free_nids */
-	if (nm_i->fcnt && !sbi->on_build_free_nids) {
+	if (nm_i->fcnt && !on_build_free_nids(nm_i)) {
 		f2fs_bug_on(list_empty(&nm_i->free_nid_list));
-		list_for_each(this, &nm_i->free_nid_list) {
-			i = list_entry(this, struct free_nid, list);
+		list_for_each_entry(i, &nm_i->free_nid_list, list)
 			if (i->state == NID_NEW)
 				break;
-		}
 
 		f2fs_bug_on(i->state != NID_NEW);
 		*nid = i->nid;
···
 
 	/* Let's scan nat pages and its caches to get free nids */
 	mutex_lock(&nm_i->build_lock);
-	sbi->on_build_free_nids = true;
 	build_free_nids(sbi);
-	sbi->on_build_free_nids = false;
 	mutex_unlock(&nm_i->build_lock);
 	goto retry;
 }
···
 	struct free_nid *i;
 
 	spin_lock(&nm_i->free_nid_list_lock);
-	i = __lookup_free_nid_list(nid, &nm_i->free_nid_list);
+	i = __lookup_free_nid_list(nm_i, nid);
 	f2fs_bug_on(!i || i->state != NID_ALLOC);
-	__del_from_free_nid_list(i);
+	__del_from_free_nid_list(nm_i, i);
 	spin_unlock(&nm_i->free_nid_list_lock);
+
+	kmem_cache_free(free_nid_slab, i);
 }
 
 /*
···
 {
 	struct f2fs_nm_info *nm_i = NM_I(sbi);
 	struct free_nid *i;
+	bool need_free = false;
 
 	if (!nid)
 		return;
 
 	spin_lock(&nm_i->free_nid_list_lock);
-	i = __lookup_free_nid_list(nid, &nm_i->free_nid_list);
+	i = __lookup_free_nid_list(nm_i, nid);
 	f2fs_bug_on(!i || i->state != NID_ALLOC);
-	if (nm_i->fcnt > 2 * MAX_FREE_NIDS) {
-		__del_from_free_nid_list(i);
+	if (!available_free_memory(nm_i, FREE_NIDS)) {
+		__del_from_free_nid_list(nm_i, i);
+		need_free = true;
 	} else {
 		i->state = NID_NEW;
 		nm_i->fcnt++;
 	}
 	spin_unlock(&nm_i->free_nid_list_lock);
+
+	if (need_free)
+		kmem_cache_free(free_nid_slab, i);
 }
 
 void recover_node_page(struct f2fs_sb_info *sbi, struct page *page,
···
 		block_t new_blkaddr)
 {
 	rewrite_node_page(sbi, page, sum, ni->blk_addr, new_blkaddr);
-	set_node_addr(sbi, ni, new_blkaddr);
+	set_node_addr(sbi, ni, new_blkaddr, false);
 	clear_node_page_dirty(page);
+}
+
+void recover_inline_xattr(struct inode *inode, struct page *page)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+	void *src_addr, *dst_addr;
+	size_t inline_size;
+	struct page *ipage;
+	struct f2fs_inode *ri;
+
+	if (!f2fs_has_inline_xattr(inode))
+		return;
+
+	if (!IS_INODE(page))
+		return;
+
+	ri = F2FS_INODE(page);
+	if (!(ri->i_inline & F2FS_INLINE_XATTR))
+		return;
+
+	ipage = get_node_page(sbi, inode->i_ino);
+	f2fs_bug_on(IS_ERR(ipage));
+
+	dst_addr = inline_xattr_addr(ipage);
+	src_addr = inline_xattr_addr(page);
+	inline_size = inline_xattr_size(inode);
+
+	memcpy(dst_addr, src_addr, inline_size);
+
+	update_inode(inode, ipage);
+	f2fs_put_page(ipage, 1);
+}
+
+bool recover_xattr_data(struct inode *inode, struct page *page, block_t blkaddr)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+	nid_t prev_xnid = F2FS_I(inode)->i_xattr_nid;
+	nid_t new_xnid = nid_of_node(page);
+	struct node_info ni;
+
+	recover_inline_xattr(inode, page);
+
+	if (!f2fs_has_xattr_block(ofs_of_node(page)))
+		return false;
+
+	/* 1: invalidate the previous xattr nid */
+	if (!prev_xnid)
+		goto recover_xnid;
+
+	/* Deallocate node address */
+	get_node_info(sbi, prev_xnid, &ni);
+	f2fs_bug_on(ni.blk_addr == NULL_ADDR);
+	invalidate_blocks(sbi, ni.blk_addr);
+	dec_valid_node_count(sbi, inode);
+	set_node_addr(sbi, &ni, NULL_ADDR, false);
+
+recover_xnid:
+	/* 2: allocate new xattr nid */
+	if (unlikely(!inc_valid_node_count(sbi, inode)))
+		f2fs_bug_on(1);
+
+	remove_free_nid(NM_I(sbi), new_xnid);
+	get_node_info(sbi, new_xnid, &ni);
+	ni.ino = inode->i_ino;
+	set_node_addr(sbi, &ni, NEW_ADDR, false);
+	F2FS_I(inode)->i_xattr_nid = new_xnid;
+
+	/* 3: update xattr blkaddr */
+	refresh_sit_entry(sbi, NEW_ADDR, blkaddr);
+	set_node_addr(sbi, &ni, blkaddr, false);
+
+	update_inode_page(inode);
+	return true;
 }
 
 int recover_inode_page(struct f2fs_sb_info *sbi, struct page *page)
···
 
 	if (unlikely(!inc_valid_node_count(sbi, NULL)))
 		WARN_ON(1);
-	set_node_addr(sbi, &new_ni, NEW_ADDR);
+	set_node_addr(sbi, &new_ni, NEW_ADDR, false);
 	inc_valid_inode_count(sbi);
 	f2fs_put_page(ipage, 1);
 	return 0;
···
 	for (; page_idx < start + nrpages; page_idx++) {
 		/* alloc temporal page for read node summary info*/
 		page = alloc_page(GFP_F2FS_ZERO);
-		if (!page) {
-			struct page *tmp;
-			list_for_each_entry_safe(page, tmp, pages, lru) {
-				list_del(&page->lru);
-				unlock_page(page);
-				__free_pages(page, 0);
-			}
-			return -ENOMEM;
-		}
+		if (!page)
+			break;
 
 		lock_page(page);
 		page->index = page_idx;
···
 		f2fs_submit_page_mbio(sbi, page, page->index, &fio);
 
 	f2fs_submit_merged_bio(sbi, META, READ);
-	return 0;
+
+	return page_idx - start;
 }
 
 int restore_node_summary(struct f2fs_sb_info *sbi,
···
 	addr = START_BLOCK(sbi, segno);
 	sum_entry = &sum->entries[0];
 
-	for (i = 0; i < last_offset; i += nrpages, addr += nrpages) {
+	for (i = 0; !err && i < last_offset; i += nrpages, addr += nrpages) {
 		nrpages = min(last_offset - i, bio_blocks);
 
 		/* read ahead node pages */
-		err = ra_sum_pages(sbi, &page_list, addr, nrpages);
-		if (err)
-			return err;
+		nrpages = ra_sum_pages(sbi, &page_list, addr, nrpages);
+		if (!nrpages)
+			return -ENOMEM;
 
 		list_for_each_entry_safe(page, tmp, &page_list, lru) {
+			if (err)
+				goto skip;
 
 			lock_page(page);
 			if (unlikely(!PageUptodate(page))) {
···
 				sum_entry->ofs_in_node = 0;
 				sum_entry++;
 			}
-
-			list_del(&page->lru);
 			unlock_page(page);
+skip:
+			list_del(&page->lru);
 			__free_pages(page, 0);
 		}
 	}
···
 	struct f2fs_nm_info *nm_i = NM_I(sbi);
 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
 	struct f2fs_summary_block *sum = curseg->sum_blk;
-	struct list_head *cur, *n;
+	struct nat_entry *ne, *cur;
 	struct page *page = NULL;
 	struct f2fs_nat_block *nat_blk = NULL;
 	nid_t start_nid = 0, end_nid = 0;
···
 		mutex_lock(&curseg->curseg_mutex);
 
 	/* 1) flush dirty nat caches */
-	list_for_each_safe(cur, n, &nm_i->dirty_nat_entries) {
-		struct nat_entry *ne;
+	list_for_each_entry_safe(ne, cur, &nm_i->dirty_nat_entries, list) {
 		nid_t nid;
 		struct f2fs_nat_entry raw_ne;
 		int offset = -1;
 		block_t new_blkaddr;
 
-		ne = list_entry(cur, struct nat_entry, list);
-		nid = nat_get_nid(ne);
-
 		if (nat_get_blkaddr(ne) == NEW_ADDR)
 			continue;
+
+		nid = nat_get_nid(ne);
+
 		if (flushed)
 			goto to_nat_page;
 
···
 		} else {
 			write_lock(&nm_i->nat_tree_lock);
 			__clear_nat_cache_dirty(nm_i, ne);
-			ne->checkpointed = true;
 			write_unlock(&nm_i->nat_tree_lock);
 		}
 	}
 	if (!flushed)
 		mutex_unlock(&curseg->curseg_mutex);
 	f2fs_put_page(page, 1);
-
-	/* 2) shrink nat caches if necessary */
-	try_to_free_nats(sbi, nm_i->nat_cnt - NM_WOUT_THRESHOLD);
 }
 
 static int init_node_manager(struct f2fs_sb_info *sbi)
···
 	/* segment_count_nat includes pair segment so divide to 2. */
 	nat_segs = le32_to_cpu(sb_raw->segment_count_nat) >> 1;
 	nat_blocks = nat_segs << le32_to_cpu(sb_raw->log_blocks_per_seg);
-	nm_i->max_nid = NAT_ENTRY_PER_BLOCK * nat_blocks;
+
+	/* not used nids: 0, node, meta, (and root counted as valid node) */
+	nm_i->max_nid = NAT_ENTRY_PER_BLOCK * nat_blocks - 3;
 	nm_i->fcnt = 0;
 	nm_i->nat_cnt = 0;
+	nm_i->ram_thresh = DEF_RAM_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_ATOMIC);
 	INIT_LIST_HEAD(&nm_i->nat_entries);
···
 	spin_lock(&nm_i->free_nid_list_lock);
 	list_for_each_entry_safe(i, next_i, &nm_i->free_nid_list, list) {
 		f2fs_bug_on(i->state == NID_ALLOC);
-		__del_from_free_nid_list(i);
+		__del_from_free_nid_list(nm_i, i);
 		nm_i->fcnt--;
+		spin_unlock(&nm_i->free_nid_list_lock);
+		kmem_cache_free(free_nid_slab, i);
+		spin_lock(&nm_i->free_nid_list_lock);
 	}
 	f2fs_bug_on(nm_i->fcnt);
 	spin_unlock(&nm_i->free_nid_list_lock);
···
 	while ((found = __gang_lookup_nat_cache(nm_i,
 					nid, NATVEC_SIZE, natvec))) {
 		unsigned idx;
-		for (idx = 0; idx < found; idx++) {
-			struct nat_entry *e = natvec[idx];
-			nid = nat_get_nid(e) + 1;
-			__del_from_nat_cache(nm_i, e);
-		}
+		nid = nat_get_nid(natvec[found - 1]) + 1;
+		for (idx = 0; idx < found; idx++)
+			__del_from_nat_cache(nm_i, natvec[idx]);
 	}
 	f2fs_bug_on(nm_i->nat_cnt);
 	write_unlock(&nm_i->nat_tree_lock);
···
 int __init create_node_manager_caches(void)
 {
 	nat_entry_slab = f2fs_kmem_cache_create("nat_entry",
-			sizeof(struct nat_entry), NULL);
+			sizeof(struct nat_entry));
 	if (!nat_entry_slab)
 		return -ENOMEM;
 
 	free_nid_slab = f2fs_kmem_cache_create("free_nid",
-			sizeof(struct free_nid), NULL);
+			sizeof(struct free_nid));
 	if (!free_nid_slab) {
 		kmem_cache_destroy(nat_entry_slab);
 		return -ENOMEM;

fs/f2fs/node.h

···
 /* # of pages to perform readahead before building free nids */
 #define FREE_NID_PAGES 4
 
-/* maximum # of free node ids to produce during build_free_nids */
-#define MAX_FREE_NIDS (NAT_ENTRY_PER_BLOCK * FREE_NID_PAGES)
-
 /* maximum readahead size for node during getting data blocks */
 #define MAX_RA_NODE		128
 
-/* maximum cached nat entries to manage memory footprint */
-#define NM_WOUT_THRESHOLD	(64 * NAT_ENTRY_PER_BLOCK)
+/* control the memory footprint threshold (10MB per 1GB ram) */
+#define DEF_RAM_THRESHOLD	10
 
 /* vector size for gang look-up from nat cache that consists of radix tree */
 #define NATVEC_SIZE	64
···
 struct nat_entry {
 	struct list_head list;	/* for clean or dirty nat list */
 	bool checkpointed;	/* whether it is checkpointed or not */
+	bool fsync_done;	/* whether the latest node has fsync mark */
 	struct node_info ni;	/* in-memory node information */
 };
 
···
 #define nat_set_version(nat, v)		(nat->ni.version = v)
 
 #define __set_nat_cache_dirty(nm_i, ne)					\
-	list_move_tail(&ne->list, &nm_i->dirty_nat_entries);
+	do {								\
+		ne->checkpointed = false;				\
+		list_move_tail(&ne->list, &nm_i->dirty_nat_entries);	\
+	} while (0);
 #define __clear_nat_cache_dirty(nm_i, ne)				\
-	list_move_tail(&ne->list, &nm_i->nat_entries);
+	do {								\
+		ne->checkpointed = true;				\
+		list_move_tail(&ne->list, &nm_i->nat_entries);		\
+	} while (0);
 #define inc_node_version(version)	(++version)
 
 static inline void node_info_from_raw_nat(struct node_info *ni,
···
 	ni->blk_addr = le32_to_cpu(raw_ne->block_addr);
 	ni->version = raw_ne->version;
 }
+
+enum nid_type {
+	FREE_NIDS,	/* indicates the free nid list */
+	NAT_ENTRIES	/* indicates the cached nat entry */
+};
 
 /*
  * For free nid mangement
···
 {
 	unsigned int ofs = ofs_of_node(node_page);
 
-	if (ofs == XATTR_NODE_OFFSET)
+	if (f2fs_has_xattr_block(ofs))
 		return false;
 
 	if (ofs == 3 || ofs == 4 + NIDS_PER_BLOCK ||

fs/f2fs/recovery.c

···
 static struct fsync_inode_entry *get_fsync_inode(struct list_head *head,
 								nid_t ino)
 {
-	struct list_head *this;
 	struct fsync_inode_entry *entry;
 
-	list_for_each(this, head) {
-		entry = list_entry(this, struct fsync_inode_entry, list);
+	list_for_each_entry(entry, head, list)
 		if (entry->inode->i_ino == ino)
 			return entry;
-	}
+
 	return NULL;
 }
 
···
 
 	/* get node pages in the current segment */
 	curseg = CURSEG_I(sbi, CURSEG_WARM_NODE);
-	blkaddr = START_BLOCK(sbi, curseg->segno) + curseg->next_blkoff;
+	blkaddr = NEXT_FREE_BLKADDR(sbi, curseg);
 
 	/* read node page */
 	page = alloc_page(GFP_F2FS_ZERO);
···
 {
 	struct seg_entry *sentry;
 	unsigned int segno = GET_SEGNO(sbi, blkaddr);
-	unsigned short blkoff = GET_SEGOFF_FROM_SEG0(sbi, blkaddr) &
-					(sbi->blocks_per_seg - 1);
+	unsigned short blkoff = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
+	struct f2fs_summary_block *sum_node;
 	struct f2fs_summary sum;
+	struct page *sum_page, *node_page;
 	nid_t ino, nid;
-	void *kaddr;
 	struct inode *inode;
-	struct page *node_page;
 	unsigned int offset;
 	block_t bidx;
 	int i;
···
 		struct curseg_info *curseg = CURSEG_I(sbi, i);
 		if (curseg->segno == segno) {
 			sum = curseg->sum_blk->entries[blkoff];
-			break;
+			goto got_it;
 		}
 	}
-	if (i > CURSEG_COLD_DATA) {
-		struct page *sum_page = get_sum_page(sbi, segno);
-		struct f2fs_summary_block *sum_node;
-		kaddr = page_address(sum_page);
-		sum_node = (struct f2fs_summary_block *)kaddr;
-		sum = sum_node->entries[blkoff];
-		f2fs_put_page(sum_page, 1);
-	}
 
+	sum_page = get_sum_page(sbi, segno);
+	sum_node = (struct f2fs_summary_block *)page_address(sum_page);
+	sum = sum_node->entries[blkoff];
+	f2fs_put_page(sum_page, 1);
+got_it:
 	/* Use the locked dnode page and inode */
 	nid = le32_to_cpu(sum.nid);
 	if (dn->inode->i_ino == nid) {
···
 	if (recover_inline_data(inode, page))
 		goto out;
 
+	if (recover_xattr_data(inode, page, blkaddr))
+		goto out;
+
 	start = start_bidx_of_node(ofs_of_node(page), fi);
 	if (IS_INODE(page))
 		end = start + ADDRS_PER_INODE(fi);
···
 		goto out;
 	}
 
-	wait_on_page_writeback(dn.node_page);
+	f2fs_wait_on_page_writeback(dn.node_page, NODE);
 
 	get_node_info(sbi, dn.nid, &ni);
 	f2fs_bug_on(ni.ino != ino_of_node(page));
···
 	bool need_writecp = false;
 
 	fsync_entry_slab = f2fs_kmem_cache_create("f2fs_fsync_inode_entry",
-			sizeof(struct fsync_inode_entry), NULL);
+			sizeof(struct fsync_inode_entry));
 	if (!fsync_entry_slab)
 		return -ENOMEM;
 

fs/f2fs/segment.c

···
 #include <linux/bio.h>
 #include <linux/blkdev.h>
 #include <linux/prefetch.h>
+#include <linux/kthread.h>
 #include <linux/vmalloc.h>
 #include <linux/swap.h>
 
···
 #define __reverse_ffz(x) __reverse_ffs(~(x))
 
 static struct kmem_cache *discard_entry_slab;
+static struct kmem_cache *flush_cmd_slab;
 
 /*
  * __reverse_ffs is copied from include/asm-generic/bitops/__ffs.h since
···
 		f2fs_sync_fs(sbi->sb, true);
 }
 
+static int issue_flush_thread(void *data)
+{
+	struct f2fs_sb_info *sbi = data;
+	struct f2fs_sm_info *sm_i = SM_I(sbi);
+	wait_queue_head_t *q = &sm_i->flush_wait_queue;
+repeat:
+	if (kthread_should_stop())
+		return 0;
+
+	spin_lock(&sm_i->issue_lock);
+	if (sm_i->issue_list) {
+		sm_i->dispatch_list = sm_i->issue_list;
+		sm_i->issue_list = sm_i->issue_tail = NULL;
+	}
+	spin_unlock(&sm_i->issue_lock);
+
+	if (sm_i->dispatch_list) {
+		struct bio *bio = bio_alloc(GFP_NOIO, 0);
+		struct flush_cmd *cmd, *next;
+		int ret;
+
+		bio->bi_bdev = sbi->sb->s_bdev;
+		ret = submit_bio_wait(WRITE_FLUSH, bio);
+
+		for (cmd = sm_i->dispatch_list; cmd; cmd = next) {
+			cmd->ret = ret;
+			next = cmd->next;
+			complete(&cmd->wait);
+		}
+		sm_i->dispatch_list = NULL;
+	}
+
+	wait_event_interruptible(*q, kthread_should_stop() || sm_i->issue_list);
+	goto repeat;
+}
+
+int f2fs_issue_flush(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_sm_info *sm_i = SM_I(sbi);
+	struct flush_cmd *cmd;
+	int ret;
+
+	if (!test_opt(sbi, FLUSH_MERGE))
+		return blkdev_issue_flush(sbi->sb->s_bdev, GFP_KERNEL, NULL);
+
+	cmd = f2fs_kmem_cache_alloc(flush_cmd_slab, GFP_ATOMIC);
+	cmd->next = NULL;
+	cmd->ret = 0;
+	init_completion(&cmd->wait);
+
+	spin_lock(&sm_i->issue_lock);
+	if (sm_i->issue_list)
+		sm_i->issue_tail->next = cmd;
+	else
+		sm_i->issue_list = cmd;
+	sm_i->issue_tail = cmd;
+	spin_unlock(&sm_i->issue_lock);
+
+	if (!sm_i->dispatch_list)
+		wake_up(&sm_i->flush_wait_queue);
+
+	wait_for_completion(&cmd->wait);
+	ret = cmd->ret;
+	kmem_cache_free(flush_cmd_slab, cmd);
+	return ret;
+}
+
 static void __locate_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno,
 		enum dirty_type dirty_type)
 {
···
 void clear_prefree_segments(struct f2fs_sb_info *sbi)
 {
 	struct list_head *head = &(SM_I(sbi)->discard_list);
-	struct list_head *this, *next;
-	struct discard_entry *entry;
+	struct discard_entry *entry, *this;
 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 	unsigned long *prefree_map = dirty_i->dirty_segmap[PRE];
 	unsigned int total_segs = TOTAL_SEGS(sbi);
···
 	mutex_unlock(&dirty_i->seglist_lock);
 
 	/* send small discards */
-	list_for_each_safe(this, next, head) {
-		entry = list_entry(this, struct discard_entry, list);
+	list_for_each_entry_safe(entry, this, head, list) {
 		f2fs_issue_discard(sbi, entry->blkaddr, entry->len);
 		list_del(&entry->list);
 		SM_I(sbi)->nr_discards -= entry->len;
···
 
 	se = get_seg_entry(sbi, segno);
 	new_vblocks = se->valid_blocks + del;
-	offset = GET_SEGOFF_FROM_SEG0(sbi, blkaddr) & (sbi->blocks_per_seg - 1);
+	offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
 
 	f2fs_bug_on((new_vblocks >> (sizeof(unsigned short) << 3) ||
 				(new_vblocks > sbi->blocks_per_seg)));
···
 		get_sec_entry(sbi, segno)->valid_blocks += del;
 }
 
-static void refresh_sit_entry(struct f2fs_sb_info *sbi,
-			block_t old_blkaddr, block_t new_blkaddr)
+void refresh_sit_entry(struct f2fs_sb_info *sbi, block_t old, block_t new)
 {
-	update_sit_entry(sbi, new_blkaddr, 1);
-	if (GET_SEGNO(sbi, old_blkaddr) != NULL_SEGNO)
-		update_sit_entry(sbi, old_blkaddr, -1);
+	update_sit_entry(sbi, new, 1);
+	if (GET_SEGNO(sbi, old) != NULL_SEGNO)
+		update_sit_entry(sbi, old, -1);
+
+	locate_dirty_segment(sbi, GET_SEGNO(sbi, old));
+	locate_dirty_segment(sbi, GET_SEGNO(sbi, new));
 }
 
 void invalidate_blocks(struct f2fs_sb_info *sbi, block_t addr)
···
 
 	stat_inc_block_count(sbi, curseg);
 
+	if (!__has_curseg_space(sbi, type))
+		sit_i->s_ops->allocate_segment(sbi, type, false);
 	/*
 	 * SIT information should be updated before segment allocation,
 	 * since SSR needs latest valid block information.
 	 */
 	refresh_sit_entry(sbi, old_blkaddr, *new_blkaddr);
-
-	if (!__has_curseg_space(sbi, type))
-		sit_i->s_ops->allocate_segment(sbi, type, false);
-
 	locate_dirty_segment(sbi, old_cursegno);
-	locate_dirty_segment(sbi, GET_SEGNO(sbi, old_blkaddr));
+
 	mutex_unlock(&sit_i->sentry_lock);
 
 	if (page && IS_NODESEG(type))
···
 		change_curseg(sbi, type, true);
 	}
 
-	curseg->next_blkoff = GET_SEGOFF_FROM_SEG0(sbi, new_blkaddr) &
-					(sbi->blocks_per_seg - 1);
+	curseg->next_blkoff = GET_BLKOFF_FROM_SEG0(sbi, new_blkaddr);
 	__add_sum_entry(sbi, type, sum);
 
 	refresh_sit_entry(sbi, old_blkaddr, new_blkaddr);
-
 	locate_dirty_segment(sbi, old_cursegno);
-	locate_dirty_segment(sbi, GET_SEGNO(sbi, old_blkaddr));
 
 	mutex_unlock(&sit_i->sentry_lock);
 	mutex_unlock(&curseg->curseg_mutex);
···
 		curseg->next_segno = segno;
 		change_curseg(sbi, type, true);
 	}
-	curseg->next_blkoff = GET_SEGOFF_FROM_SEG0(sbi, new_blkaddr) &
-					(sbi->blocks_per_seg - 1);
+	curseg->next_blkoff = GET_BLKOFF_FROM_SEG0(sbi, new_blkaddr);
 	__add_sum_entry(sbi, type, sum);
 
 	/* change the current log to the next block addr in advance */
···
 		curseg->next_segno = next_segno;
 		change_curseg(sbi, type, true);
 	}
-	curseg->next_blkoff = GET_SEGOFF_FROM_SEG0(sbi, next_blkaddr) &
-					(sbi->blocks_per_seg - 1);
+	curseg->next_blkoff = GET_BLKOFF_FROM_SEG0(sbi, next_blkaddr);
 
 	/* rewrite node page */
 	set_page_writeback(page);
 	f2fs_submit_page_mbio(sbi, page, new_blkaddr, &fio);
 	f2fs_submit_merged_bio(sbi, NODE, WRITE);
 	refresh_sit_entry(sbi, old_blkaddr, new_blkaddr);
-
 	locate_dirty_segment(sbi, old_cursegno);
-	locate_dirty_segment(sbi, GET_SEGNO(sbi, old_blkaddr));
 
 	mutex_unlock(&sit_i->sentry_lock);
 	mutex_unlock(&curseg->curseg_mutex);
+}
+
+static inline bool is_merged_page(struct f2fs_sb_info *sbi,
+					struct page *page, enum page_type type)
+{
+	enum page_type btype = PAGE_TYPE_OF_BIO(type);
+	struct f2fs_bio_info *io = &sbi->write_io[btype];
+	struct bio_vec *bvec;
+	int i;
+
+	down_read(&io->io_rwsem);
+	if (!io->bio)
+		goto out;
+
+	bio_for_each_segment_all(bvec, io->bio, i) {
+		if (page == bvec->bv_page) {
+			up_read(&io->io_rwsem);
+			return true;
+		}
+	}
+
+out:
+	up_read(&io->io_rwsem);
+	return false;
 }
 
 void f2fs_wait_on_page_writeback(struct page *page,
···
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(page->mapping->host->i_sb);
 	if (PageWriteback(page)) {
-		f2fs_submit_merged_bio(sbi, type, WRITE);
+		if (is_merged_page(sbi, page, type))
+			f2fs_submit_merged_bio(sbi, type, WRITE);
 		wait_on_page_writeback(page);
 	}
 }
···
 				ns->ofs_in_node = 0;
 			}
 		} else {
-			if (restore_node_summary(sbi, segno, sum)) {
+			int err;
+
+			err = restore_node_summary(sbi, segno, sum);
+			if (err) {
 				f2fs_put_page(new, 1);
-				return -EINVAL;
+				return err;
 			}
 		}
 	}
···
 static int restore_curseg_summaries(struct f2fs_sb_info *sbi)
 {
 	int type = CURSEG_HOT_DATA;
+	int err;
 
 	if (is_set_ckpt_flags(F2FS_CKPT(sbi), CP_COMPACT_SUM_FLAG)) {
 		/* restore for compacted data summary */
···
 		type = CURSEG_HOT_NODE;
 	}
 
-	for (; type <= CURSEG_COLD_NODE; type++)
-		if (read_normal_summaries(sbi, type))
-			return -EINVAL;
+	for (; type <= CURSEG_COLD_NODE; type++) {
+		err = read_normal_summaries(sbi, type);
+		if (err)
+			return err;
+	}
+
 	return 0;
 }
 
···
 	return restore_curseg_summaries(sbi);
 }
 
-static int ra_sit_pages(struct f2fs_sb_info *sbi, int start, int nrpages)
-{
-	struct address_space *mapping = META_MAPPING(sbi);
-	struct page *page;
-	block_t blk_addr, prev_blk_addr = 0;
-	int sit_blk_cnt = SIT_BLK_CNT(sbi);
-	int blkno = start;
-	struct f2fs_io_info fio = {
-		.type = META,
-		.rw = READ_SYNC | REQ_META | REQ_PRIO
-	};
-
-	for (; blkno < start + nrpages && blkno < sit_blk_cnt; blkno++) {
-
-		blk_addr = current_sit_addr(sbi, blkno * SIT_ENTRY_PER_BLOCK);
-
-		if (blkno != start && prev_blk_addr + 1 != blk_addr)
-			break;
-		prev_blk_addr = blk_addr;
-repeat:
-		page = grab_cache_page(mapping, blk_addr);
-		if (!page) {
-			cond_resched();
-			goto repeat;
-		}
-		if (PageUptodate(page)) {
-			mark_page_accessed(page);
-			f2fs_put_page(page, 1);
-			continue;
-		}
-
-		f2fs_submit_page_mbio(sbi, page, blk_addr, &fio);
-
-		mark_page_accessed(page);
-		f2fs_put_page(page, 0);
-	}
-
-	f2fs_submit_merged_bio(sbi, META, READ);
-	return blkno - start;
-}
-
 static void build_sit_entries(struct f2fs_sb_info *sbi)
 {
 	struct sit_info *sit_i = SIT_I(sbi);
···
 	int nrpages = MAX_BIO_BLOCKS(max_hw_blocks(sbi));
 
 	do {
-		readed = ra_sit_pages(sbi, start_blk, nrpages);
+		readed = ra_meta_pages(sbi, start_blk, nrpages, META_SIT);
 
 		start = start_blk * sit_i->sents_per_block;
 		end = (start_blk + readed) * sit_i->sents_per_block;
···
 {
 	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
+	dev_t dev = sbi->sb->s_bdev->bd_dev;
 	struct f2fs_sm_info *sm_info;
 	int err;
 
···
 	sm_info->ovp_segments = le32_to_cpu(ckpt->overprov_segment_count);
 	sm_info->main_segments = le32_to_cpu(raw_super->segment_count_main);
 	sm_info->ssa_blkaddr = le32_to_cpu(raw_super->ssa_blkaddr);
-	sm_info->rec_prefree_segments = DEF_RECLAIM_PREFREE_SEGMENTS;
+	sm_info->rec_prefree_segments = sm_info->main_segments *
+					DEF_RECLAIM_PREFREE_SEGMENTS / 100;
 	sm_info->ipu_policy = F2FS_IPU_DISABLE;
 	sm_info->min_ipu_util = DEF_MIN_IPU_UTIL;
 
 	INIT_LIST_HEAD(&sm_info->discard_list);
 	sm_info->nr_discards = 0;
 	sm_info->max_discards = 0;
+
+	if (test_opt(sbi, FLUSH_MERGE)) {
+		spin_lock_init(&sm_info->issue_lock);
+		init_waitqueue_head(&sm_info->flush_wait_queue);
+
+		sm_info->f2fs_issue_flush = kthread_run(issue_flush_thread, sbi,
+				"f2fs_flush-%u:%u", MAJOR(dev), MINOR(dev));
+		if (IS_ERR(sm_info->f2fs_issue_flush))
+			return PTR_ERR(sm_info->f2fs_issue_flush);
+	}
 
 	err = build_sit_info(sbi);
 	if (err)
···
 	struct f2fs_sm_info *sm_info = SM_I(sbi);
 	if (!sm_info)
 		return;
+	if (sm_info->f2fs_issue_flush)
+		kthread_stop(sm_info->f2fs_issue_flush);
 	destroy_dirty_segmap(sbi);
 	destroy_curseg(sbi);
 	destroy_free_segmap(sbi);
···
 int __init create_segment_manager_caches(void)
 {
 	discard_entry_slab = f2fs_kmem_cache_create("discard_entry",
-			sizeof(struct discard_entry), NULL);
+			sizeof(struct discard_entry));
 	if (!discard_entry_slab)
 		return -ENOMEM;
+	flush_cmd_slab = f2fs_kmem_cache_create("flush_command",
+			sizeof(struct flush_cmd));
+	if (!flush_cmd_slab) {
+		kmem_cache_destroy(discard_entry_slab);
+		return -ENOMEM;
+	}
 	return 0;
 }
 
 void destroy_segment_manager_caches(void)
 {
 	kmem_cache_destroy(discard_entry_slab);
+	kmem_cache_destroy(flush_cmd_slab);
 }

fs/f2fs/segment.h

···
 #define NULL_SEGNO			((unsigned int)(~0))
 #define NULL_SECNO			((unsigned int)(~0))
 
-#define DEF_RECLAIM_PREFREE_SEGMENTS	100	/* 200MB of prefree segments */
+#define DEF_RECLAIM_PREFREE_SEGMENTS	5	/* 5% over total segments */
 
 /* L: Logical segment # in volume, R: Relative segment # in main area */
 #define GET_L2R_SEGNO(free_i, segno)	(segno - free_i->start_segno)
···
 	((blk_addr) - SM_I(sbi)->seg0_blkaddr)
 #define GET_SEGNO_FROM_SEG0(sbi, blk_addr)				\
 	(GET_SEGOFF_FROM_SEG0(sbi, blk_addr) >> sbi->log_blocks_per_seg)
+#define GET_BLKOFF_FROM_SEG0(sbi, blk_addr)				\
+	(GET_SEGOFF_FROM_SEG0(sbi, blk_addr) & (sbi->blocks_per_seg - 1))
+
 #define GET_SEGNO(sbi, blk_addr)					\
 	(((blk_addr == NULL_ADDR) || (blk_addr == NEW_ADDR)) ?		\
 	NULL_SEGNO : GET_L2R_SEGNO(FREE_I(sbi),			\
···
 
 static inline block_t written_block_count(struct f2fs_sb_info *sbi)
 {
-	struct sit_info *sit_i = SIT_I(sbi);
-	block_t vblocks;
-
-	mutex_lock(&sit_i->sentry_lock);
-	vblocks = sit_i->written_valid_blocks;
-	mutex_unlock(&sit_i->sentry_lock);
-
-	return vblocks;
+	return SIT_I(sbi)->written_valid_blocks;
 }
 
 static inline unsigned int free_segments(struct f2fs_sb_info *sbi)
 {
-	struct free_segmap_info *free_i = FREE_I(sbi);
-	unsigned int free_segs;
-
-	read_lock(&free_i->segmap_lock);
-	free_segs = free_i->free_segments;
-	read_unlock(&free_i->segmap_lock);
-
-	return free_segs;
+	return FREE_I(sbi)->free_segments;
 }
 
 static inline int reserved_segments(struct f2fs_sb_info *sbi)
···
 
 static inline unsigned int free_sections(struct f2fs_sb_info *sbi)
 {
-	struct free_segmap_info *free_i = FREE_I(sbi);
-	unsigned int free_secs;
-
-	read_lock(&free_i->segmap_lock);
-	free_secs = free_i->free_sections;
-	read_unlock(&free_i->segmap_lock);
-
-	return free_secs;
+	return FREE_I(sbi)->free_sections;
 }
 
 static inline unsigned int prefree_segments(struct f2fs_sb_info *sbi)
···
 	struct block_device *bdev = sbi->sb->s_bdev;
 	struct request_queue *q = bdev_get_queue(bdev);
 	return SECTOR_TO_BLOCK(sbi, queue_max_sectors(q));
+}
+
+/*
+ * It is very important to gather dirty pages and write at once, so that we can
+ * submit a big bio without interfering other data writes.
+ * By default, 512 pages for directory data,
+ * 512 pages (2MB) * 3 for three types of nodes, and
+ * max_bio_blocks for meta are set.
+ */
+static inline int nr_pages_to_skip(struct f2fs_sb_info *sbi, int type)
+{
+	if (type == DATA)
+		return sbi->blocks_per_seg;
+	else if (type == NODE)
+		return 3 * sbi->blocks_per_seg;
+	else if (type == META)
+		return MAX_BIO_BLOCKS(max_hw_blocks(sbi));
+	else
+		return 0;
+}
+
+/*
+ * When writing pages, it'd better align nr_to_write for segment size.
+ */
+static inline long nr_pages_to_write(struct f2fs_sb_info *sbi, int type,
+					struct writeback_control *wbc)
+{
+	long nr_to_write, desired;
+
+	if (wbc->sync_mode != WB_SYNC_NONE)
+		return 0;
+
+	nr_to_write = wbc->nr_to_write;
+
+	if (type == DATA)
+		desired = 4096;
+	else if (type == NODE)
+		desired = 3 * max_hw_blocks(sbi);
+	else
+		desired = MAX_BIO_BLOCKS(max_hw_blocks(sbi));
+
+	wbc->nr_to_write = desired;
+	return desired - nr_to_write;
 }

fs/f2fs/super.c

···
 	Opt_disable_ext_identify,
 	Opt_inline_xattr,
 	Opt_inline_data,
+	Opt_flush_merge,
 	Opt_err,
 };
 
···
 	{Opt_disable_ext_identify, "disable_ext_identify"},
 	{Opt_inline_xattr, "inline_xattr"},
 	{Opt_inline_data, "inline_data"},
+	{Opt_flush_merge, "flush_merge"},
 	{Opt_err, NULL},
 };
 
···
 enum {
 	GC_THREAD,	/* struct f2fs_gc_thread */
 	SM_INFO,	/* struct f2fs_sm_info */
+	NM_INFO,	/* struct f2fs_nm_info */
 	F2FS_SBI,	/* struct f2fs_sb_info */
 };
 
···
 		return (unsigned char *)sbi->gc_thread;
 	else if (struct_type == SM_INFO)
 		return (unsigned char *)SM_I(sbi);
+	else if (struct_type == NM_INFO)
+		return (unsigned char *)NM_I(sbi);
 	else if (struct_type == F2FS_SBI)
 		return (unsigned char *)sbi;
 	return NULL;
···
 F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, max_small_discards, max_discards);
 F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, ipu_policy, ipu_policy);
 F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_ipu_util, min_ipu_util);
+F2FS_RW_ATTR(NM_INFO, f2fs_nm_info, ram_thresh, ram_thresh);
 F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, max_victim_search, max_victim_search);
+F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, dir_level, dir_level);
 
 #define ATTR_LIST(name) (&f2fs_attr_##name.attr)
 static struct attribute *f2fs_attrs[] = {
···
 	ATTR_LIST(ipu_policy),
 	ATTR_LIST(min_ipu_util),
 	ATTR_LIST(max_victim_search),
+	ATTR_LIST(dir_level),
+	ATTR_LIST(ram_thresh),
 	NULL,
 };
 
···
 
 			if (!name)
 				return -ENOMEM;
-			if (!strncmp(name, "on", 2))
+			if (strlen(name) == 2 && !strncmp(name, "on", 2))
 				set_opt(sbi, BG_GC);
-			else if (!strncmp(name, "off", 3))
+			else if (strlen(name) == 3 && !strncmp(name, "off", 3))
 				clear_opt(sbi, BG_GC);
 			else {
 				kfree(name);
···
 		case Opt_inline_data:
 			set_opt(sbi, INLINE_DATA);
 			break;
+		case Opt_flush_merge:
+			set_opt(sbi, FLUSH_MERGE);
+			break;
 		default:
 			f2fs_msg(sb, KERN_ERR,
 				"Unrecognized mount option \"%s\" or missing value",
···
 	fi->i_current_depth = 1;
 	fi->i_advise = 0;
 	rwlock_init(&fi->ext.ext_lock);
+	init_rwsem(&fi->i_sem);
 
 	set_inode_flag(fi, FI_NEW_INODE);
 
 	if (test_opt(F2FS_SB(sb), INLINE_XATTR))
 		set_inode_flag(fi, FI_INLINE_XATTR);
+
+	/* Will be used by directory only */
+	fi->i_dir_level = F2FS_SB(sb)->dir_level;
 
 	return &fi->vfs_inode;
 }
···
 		seq_puts(seq, ",disable_ext_identify");
 	if (test_opt(sbi, INLINE_DATA))
 		seq_puts(seq, ",inline_data");
+	if (test_opt(sbi, FLUSH_MERGE))
+		seq_puts(seq, ",flush_merge");
 	seq_printf(seq, ",active_logs=%u", sbi->active_logs);
 
 	return 0;
···
 			le32_to_cpu(sbi->raw_super->segment_count_main);
 	int i;
 
+	seq_puts(seq, "format: segment_type|valid_blocks\n"
+		"segment_type(0:HD, 1:WD, 2:CD, 3:HN, 4:WN, 5:CN)\n");
+
 	for (i = 0; i < total_segs; i++) {
-		seq_printf(seq, "%u", get_valid_blocks(sbi, i, 1));
-		if (i != 0 && (i % 10) == 0)
-			seq_puts(seq, "\n");
+		struct seg_entry *se = get_seg_entry(sbi, i);
+
+		if ((i % 10) == 0)
+			seq_printf(seq, "%-5d", i);
+		seq_printf(seq, "%d|%-3u", se->type,
+					get_valid_blocks(sbi, i, 1));
+		if ((i % 10) == 9 || i == (total_segs - 1))
+			seq_putc(seq, '\n');
 		else
-			seq_puts(seq, " ");
+			seq_putc(seq, ' ');
 	}
+
 	return 0;
 }
 
···
 	struct inode *inode;
 
 	if (unlikely(ino < F2FS_ROOT_INO(sbi)))
+		return ERR_PTR(-ESTALE);
+	if (unlikely(ino >= NM_I(sbi)->max_nid))
 		return ERR_PTR(-ESTALE);
 
 	/*
···
 
 	for (i = 0; i < NR_COUNT_TYPE; i++)
 		atomic_set(&sbi->nr_pages[i], 0);
+
+	sbi->dir_level = DEF_DIR_LEVEL;
 }
 
 /*
···
 	sbi->por_doing = false;
 	spin_lock_init(&sbi->stat_lock);
 
-	mutex_init(&sbi->read_io.io_mutex);
+	init_rwsem(&sbi->read_io.io_rwsem);
 	sbi->read_io.sbi = sbi;
 	sbi->read_io.bio = NULL;
 	for (i = 0; i < NR_PAGE_TYPE; i++) {
-		mutex_init(&sbi->write_io[i].io_mutex);
+		init_rwsem(&sbi->write_io[i].io_rwsem);
 		sbi->write_io[i].sbi = sbi;
 		sbi->write_io[i].bio = NULL;
 	}
···
 		goto free_root_inode;
 	}
 
-	/* recover fsynced data */
-	if (!test_opt(sbi, DISABLE_ROLL_FORWARD)) {
-		err = recover_fsync_data(sbi);
-		if (err)
-			f2fs_msg(sb, KERN_ERR,
-				"Cannot recover all fsync data errno=%ld", err);
-	}
-
-	/*
-	 * If filesystem is not mounted as read-only then
-	 * do start the gc_thread.
-	 */
-	if (!(sb->s_flags & MS_RDONLY)) {
-		/* After POR, we can run background GC thread.*/
-		err = start_gc_thread(sbi);
-		if (err)
-			goto free_gc;
-	}
-
 	err = f2fs_build_stats(sbi);
 	if (err)
-		goto free_gc;
+		goto free_root_inode;
 
 	if (f2fs_proc_root)
 		sbi->s_proc = proc_mkdir(sb->s_id, f2fs_proc_root);
···
 	err = kobject_init_and_add(&sbi->s_kobj, &f2fs_ktype, NULL,
 							"%s", sb->s_id);
 	if (err)
-		goto fail;
+		goto free_proc;
 
+	/* recover fsynced data */
+	if (!test_opt(sbi, DISABLE_ROLL_FORWARD)) {
+		err = recover_fsync_data(sbi);
+		if (err)
+			f2fs_msg(sb, KERN_ERR,
+				"Cannot recover all fsync data errno=%ld", err);
+	}
+
+	/*
+	 * If filesystem is not mounted as read-only then
+	 * do start the gc_thread.
+	 */
+	if (!(sb->s_flags & MS_RDONLY)) {
+		/* After POR, we can run background GC thread.*/
+		err = start_gc_thread(sbi);
+		if (err)
+			goto free_kobj;
+	}
 	return 0;
-fail:
+
+free_kobj:
+	kobject_del(&sbi->s_kobj);
+free_proc:
 	if (sbi->s_proc) {
 		remove_proc_entry("segment_info", sbi->s_proc);
 		remove_proc_entry(sb->s_id, f2fs_proc_root);
 	}
 	f2fs_destroy_stats(sbi);
-free_gc:
-	stop_gc_thread(sbi);
 free_root_inode:
 	dput(sb->s_root);
 	sb->s_root = NULL;
···
 static int __init init_inodecache(void)
 {
 	f2fs_inode_cachep = f2fs_kmem_cache_create("f2fs_inode_cache",
-			sizeof(struct f2fs_inode_info), NULL);
+			sizeof(struct f2fs_inode_info));
 	if (!f2fs_inode_cachep)
 		return -ENOMEM;
 	return 0;

fs/f2fs/xattr.c

···
 
 	inline_size = inline_xattr_size(inode);
 
-	txattr_addr = kzalloc(inline_size + size, GFP_KERNEL);
+	txattr_addr = kzalloc(inline_size + size, GFP_F2FS_ZERO);
 	if (!txattr_addr)
 		return NULL;
 
···
 	if (name == NULL)
 		return -EINVAL;
 	name_len = strlen(name);
+	if (name_len > F2FS_NAME_LEN)
+		return -ERANGE;
 
 	base_addr = read_all_xattrs(inode, NULL);
 	if (!base_addr)
···
 	f2fs_balance_fs(sbi);
 
 	f2fs_lock_op(sbi);
+	/* protect xattr_ver */
+	down_write(&F2FS_I(inode)->i_sem);
 	err = __f2fs_setxattr(inode, name_index, name, value, value_len, ipage);
+	up_write(&F2FS_I(inode)->i_sem);
 	f2fs_unlock_op(sbi);
 
 	return err;

include/linux/f2fs_fs.h

···
 	__le32 i_pino;			/* parent inode number */
 	__le32 i_namelen;		/* file name length */
 	__u8 i_name[F2FS_NAME_LEN];	/* file name for SPOR */
-	__u8 i_reserved2;		/* for backward compatibility */
+	__u8 i_dir_level;		/* dentry_level for large dir */
 
 	struct f2fs_extent i_ext;	/* caching a largest extent */