f2fs: support project quota

This patch adds to support plain project quota.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
index 0c79ddd..50f1766 100644
--- a/include/linux/f2fs_fs.h
+++ b/include/linux/f2fs_fs.h
@@ -239,6 +239,7 @@ struct f2fs_inode {
 		struct {
 			__le16 i_extra_isize;	/* extra inode attribute size */
 			__le16 i_padding;	/* padding */
+			__le32 i_projid;	/* project id */
 			__le32 i_extra_end[0];	/* for attribute size calculation */
 		};
 		__le32 i_addr[DEF_ADDRS_PER_INODE];	/* Pointers to data blocks */
@@ -522,4 +523,6 @@ enum {
 
 #define S_SHIFT 12
 
+#define	F2FS_DEF_PROJID		0	/* default project ID */
+
 #endif  /* _LINUX_F2FS_FS_H */