[systemd-devel] journal file boot_id and tail_entry_monotonic

[Lennart Poettering]

On Do, 15.03.18 07:02, Matthijs van Duin (matthijsvanduin at gmail.com) wrote:

> While studying a bit how journal works, I noticed something odd:
> 
> My understanding of the boot_id field in the file header is that it should
> reflect the boot_id of the tail entry, to allow correct interpretation of
> the tail_entry_monotonic timestamp. This also agrees with the checks done
> by journal_file_verify().
> 
> However, in journal_file_refresh_header(), the boot_id field is updated to
> the current boot id even though no entry is being added there. This is even
> being done before the journal file is set online!

I am pretty sure the boot ID should reflect the boot the file was last
set online on. Hence I'd say journal_file_verify() is wrong, and
journal_file_refresh_header() is right.

Will fix!

> Shouldn't the header boot_id instead be refreshed
> in journal_file_link_entry(), where the tail_entry timestamps are being
> updated?
> 
> (also, the tail_entry_monotonic_valid flag of JournalFile doesn't seem to
> get tested anywhere?)

True! I guess we can drop that.

Will fix, too!

Thanks for the hints, such code reviews are very welcome!

Lennart

-- 
Lennart Poettering, Red Hat