f2fs: enable inline dir handling

Add inline dir functions into normal dir ops' function to handle inline ops.
Besides, we enable inline dir mode when a new dir inode is created if
inline_data option is on.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/file.c

@@ -314,7 +314,7 @@ static loff_t f2fs_seek_block(struct file *file, loff_t offset, int whence)
 		goto fail;
 
 	/* handle inline data case */
-	if (f2fs_has_inline_data(inode)) {
+	if (f2fs_has_inline_data(inode) || f2fs_has_inline_dentry(inode)) {
 		if (whence == SEEK_HOLE)
 			data_ofs = isize;
 		goto found;