Define/reserve new ext4 superblock fields

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

include/linux/ext4_fs.h

@@ -513,7 +513,14 @@ struct ext4_super_block {
 /*150*/	__le32	s_blocks_count_hi;	/* Blocks count */
 	__le32	s_r_blocks_count_hi;	/* Reserved blocks count */
 	__le32	s_free_blocks_count_hi;	/* Free blocks count */
-	__u32	s_reserved[169];	/* Padding to the end of the block */
+	__u16	s_min_extra_isize;	/* All inodes have at least # bytes */
+	__u16	s_want_extra_isize; 	/* New inodes should reserve # bytes */
+	__u32	s_flags;		/* Miscellaneous flags */
+	__u16   s_raid_stride;		/* RAID stride */
+	__u16   s_mmp_interval;         /* # seconds to wait in MMP checking */
+	__u64   s_mmp_block;            /* Block for multi-mount protection */
+	__u32   s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
+	__u32   s_reserved[163];        /* Padding to the end of the block */
 };
 
 #ifdef __KERNEL__