few ext2/ext3 questions (i_blocks usage and updating superblock in r-only)

[Evgeniy Ivanov <lolkaantimat@gmail.com>]

Hello,

What is correct way to treat i_blocks? i_blocks is a block counter,
but its values differ from real number of used blocks (e.g. 1 block is
used and written to i_block, but i_blocks is set to 8 and if I set
i_blocks to 1 e2fsck always wants to set it to 8). As I understand
preallocation shouldn't affect i_blocks and there are no unix holes.

Nothing on fs should be updated, when it's mounted in r-only (I mean
mount time, mount point attributes of superblock), right?

Btw, when I don't have problems with i_blocks, e2fsck's exit status is
1 (my ext2 implementation is guilty), but it doesn't say what was
wrong even with "-v". How can I get more verbose results?

Thanks in advance for any help.

--
Evgeniy Ivanov