f2fs: avoid multiple node page writes due to inline_data

The sceanrio is:
1. create fully node blocks
2. flush node blocks
3. write inline_data for all the node blocks again
4. flush node blocks redundantly

So, this patch tries to flush inline_data when flushing node blocks.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/data.c

@@ -1463,6 +1463,7 @@ static int prepare_write_begin(struct f2fs_sb_info *sbi,
 		if (pos + len <= MAX_INLINE_DATA) {
 			read_inline_data(page, ipage);
 			set_inode_flag(F2FS_I(inode), FI_DATA_EXIST);
+			set_inline_node(ipage);
 			sync_inode_page(&dn);
 		} else {
 			err = f2fs_convert_inline_page(&dn, page);

fs/f2fs/inline.c

@@ -159,6 +159,7 @@ int f2fs_convert_inline_page(struct dnode_of_data *dn, struct page *page)
 
 	/* clear inline data and flag after data writeback */
 	truncate_inline_inode(dn->inode_page, 0);
+	clear_inline_node(dn->inode_page);
 clear_out:
 	stat_dec_inline_inode(dn->inode);
 	f2fs_clear_inline_inode(dn->inode);
@@ -233,6 +234,7 @@ int f2fs_write_inline_data(struct inode *inode, struct page *page)
 	set_inode_flag(F2FS_I(inode), FI_DATA_EXIST);
 
 	sync_inode_page(&dn);
+	clear_inline_node(dn.inode_page);
 	f2fs_put_dnode(&dn);
 	return 0;
 }

fs/f2fs/inode.c

@@ -263,6 +263,10 @@ int update_inode(struct inode *inode, struct page *node_page)
 	set_cold_node(inode, node_page);
 	clear_inode_flag(F2FS_I(inode), FI_DIRTY_INODE);
 
+	/* deleted inode */
+	if (inode->i_nlink == 0)
+		clear_inline_node(node_page);
+
 	return set_page_dirty(node_page);
 }
 

fs/f2fs/node.c

@@ -1154,6 +1154,39 @@ void sync_inode_page(struct dnode_of_data *dn)
 	dn->node_changed = ret ? true: false;
 }
 
+static void flush_inline_data(struct f2fs_sb_info *sbi, nid_t ino)
+{
+	struct inode *inode;
+	struct page *page;
+
+	/* should flush inline_data before evict_inode */
+	inode = ilookup(sbi->sb, ino);
+	if (!inode)
+		return;
+
+	page = pagecache_get_page(inode->i_mapping, 0, FGP_LOCK|FGP_NOWAIT, 0);
+	if (!page)
+		goto iput_out;
+
+	if (!PageUptodate(page))
+		goto page_out;
+
+	if (!PageDirty(page))
+		goto page_out;
+
+	if (!clear_page_dirty_for_io(page))
+		goto page_out;
+
+	if (!f2fs_write_inline_data(inode, page))
+		inode_dec_dirty_pages(inode);
+	else
+		set_page_dirty(page);
+page_out:
+	f2fs_put_page(page, 1);
+iput_out:
+	iput(inode);
+}
+
 int sync_node_pages(struct f2fs_sb_info *sbi, nid_t ino,
 					struct writeback_control *wbc)
 {
@@ -1221,6 +1254,14 @@ int sync_node_pages(struct f2fs_sb_info *sbi, nid_t ino,
 				goto continue_unlock;
 			}
 
+			/* flush inline_data */
+			if (!ino && is_inline_node(page)) {
+				clear_inline_node(page);
+				unlock_page(page);
+				flush_inline_data(sbi, ino_of_node(page));
+				continue;
+			}
+
 			if (!clear_page_dirty_for_io(page))
 				goto continue_unlock;
 

fs/f2fs/node.h

@@ -379,6 +379,21 @@ static inline int is_node(struct page *page, int type)
 #define is_fsync_dnode(page)	is_node(page, FSYNC_BIT_SHIFT)
 #define is_dent_dnode(page)	is_node(page, DENT_BIT_SHIFT)
 
+static inline int is_inline_node(struct page *page)
+{
+	return PageChecked(page);
+}
+
+static inline void set_inline_node(struct page *page)
+{
+	SetPageChecked(page);
+}
+
+static inline void clear_inline_node(struct page *page)
+{
+	ClearPageChecked(page);
+}
+
 static inline void set_cold_node(struct inode *inode, struct page *page)
 {
 	struct f2fs_node *rn = F2FS_NODE(page);