1) tune2fs hiccups when presented with journal device fs. Should it instead at least report "this is a journal device" rather than "invalid super block"?
2) no way to create journal_dev with metadata_csum. This would provide checksum for the fs superblock.
3) dumpe2fs should still display journal flags for journal_dev; currently it fails to display journal flags.
4) s_jnl_blocks in the superblock should be zeroed when removing a journal (ie ^has_journal) or when setting the journal to journal_dev. Currently, the legacy (now dead) block list is maintained. I'd argue that will invite misuse.
On Thu, Sep 04, 2014 at 12:14:32AM -0400, TR Reardon wrote:
> 1) tune2fs hiccups when presented with journal device fs. Should it instead
> at least report "this is a journal device" rather than "invalid super block"?
Yes. e2fsck/debugfs seem to issue the 'unsupported features' complaint but
without the 'invalid superblock' wording.
> 2) no way to create journal_dev with metadata_csum. This would provide
> checksum for the fs superblock.
Not sure how useful this is since most of the SB is irrelevant here. But I
don't see any reason why we shouldn't let users turn it on.
> 3) dumpe2fs should still display journal flags for journal_dev; currently it
> fails to display journal flags.
Ick. Yes, that should work.
> 4) s_jnl_blocks in the superblock should be zeroed when removing a journal
> (ie ^has_journal) or when setting the journal to journal_dev. Currently, the
> legacy (now dead) block list is maintained. I'd argue that will invite
> misuse.
Seems like a reasonable precaution.
Now, does anyone know why ext4 reports a df size of 64ZB when I create an
external journal FS? :)
--D