confused on different inode size

[coly <colyli@gmail.com>]

Hi, list:

I find size of struct ext4_inode is 152 bytes, but from the dumpe2fs, it
tells me the inode size is 128 bytes.

I am confused that, the ext4_inode is the on-disk inode format, so how
can dumpe2fs tells the inode size is 128 bytes.

Further more, when I use sb_bread() to read inode from inode table (with
152 bytes inode size), I can not read proper data from the bh->b_data.
Once I use 128 bytes inode size, I can read what I want from the
bh->b_data.

I believe there is something I missed, can anybody give me some points ?

Thanks in advance.

Coly