f2fs: use extent cache for dir

We update extent cache for all user inode of f2fs including dir inode, so this
patch gives another chance to try to get physical address of page from extent
cache for dir inode.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/data.c

@@ -806,6 +806,7 @@ struct page *find_data_page(struct inode *inode, pgoff_t index, bool sync)
 	struct address_space *mapping = inode->i_mapping;
 	struct dnode_of_data dn;
 	struct page *page;
+	struct extent_info ei;
 	int err;
 	struct f2fs_io_info fio = {
 		.type = DATA,
@@ -817,6 +818,11 @@ struct page *find_data_page(struct inode *inode, pgoff_t index, bool sync)
 		return page;
 	f2fs_put_page(page, 0);
 
+	if (f2fs_lookup_extent_cache(inode, index, &ei)) {
+		dn.data_blkaddr = ei.blk + index - ei.fofs;
+		goto got_it;
+	}
+
 	set_new_dnode(&dn, inode, NULL, NULL, 0);
 	err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
 	if (err)
@@ -830,6 +836,7 @@ struct page *find_data_page(struct inode *inode, pgoff_t index, bool sync)
 	if (unlikely(dn.data_blkaddr == NEW_ADDR))
 		return ERR_PTR(-EINVAL);
 
+got_it:
 	page = grab_cache_page(mapping, index);
 	if (!page)
 		return ERR_PTR(-ENOMEM);
@@ -864,6 +871,7 @@ struct page *get_lock_data_page(struct inode *inode, pgoff_t index)
 	struct address_space *mapping = inode->i_mapping;
 	struct dnode_of_data dn;
 	struct page *page;
+	struct extent_info ei;
 	int err;
 	struct f2fs_io_info fio = {
 		.type = DATA,
@@ -874,6 +882,11 @@ struct page *get_lock_data_page(struct inode *inode, pgoff_t index)
 	if (!page)
 		return ERR_PTR(-ENOMEM);
 
+	if (f2fs_lookup_extent_cache(inode, index, &ei)) {
+		dn.data_blkaddr = ei.blk + index - ei.fofs;
+		goto got_it;
+	}
+
 	set_new_dnode(&dn, inode, NULL, NULL, 0);
 	err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
 	if (err) {
@@ -887,6 +900,7 @@ struct page *get_lock_data_page(struct inode *inode, pgoff_t index)
 		return ERR_PTR(-ENOENT);
 	}
 
+got_it:
 	if (PageUptodate(page))
 		return page;