[sheepdog] [PATCH v5 5/7] sheep: rename journal_file.c as journal.c

MORITA Kazutaka morita.kazutaka at lab.ntt.co.jp
Mon Apr 8 06:21:08 CEST 2013

At Mon, 08 Apr 2013 10:52:52 +0800,
Liu Yuan wrote:
> On 04/08/2013 12:48 AM, Hitoshi Mitake wrote:
> > I have a naive question about the design of this journaling
> > mechanism. It seems that jfile.pos is increased when new journal entry
> > is appended and is set as 0 when switching of journal files is caused.
> > 
> > So the replay_journal_entry() has a possibility of overwriting epoch,
> > config, and object with identical data which is already stored in the
> > files. This may cause an overhead during initialization process of
> > sheep.
> The rewrite happens only at the case that sheep crashes before journal
> committing. The normal process(jsize = 0) won't trigger journal
> recovery. But, there might be a corner case for shutdown. At shutdown,
> we should assure journal is committed (jfile size is set to 0). But this
> is out of scope of this patch set. It would be great if you can submit a

Then, I think it's better to explain what is not implemented yet in
the commit log or source code.



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