[Ocfs2-devel] Question about incorrect free bits setting

[Goldwyn Rodrigues]

Hi joseph,

On 03/26/2015 09:27 PM, Joseph Qi wrote:
> Hi Goldwyn,
> I found you posted a mail to discuss about incorrect free bits setting.
> https://oss.oracle.com/pipermail/ocfs2-devel/2012-January/008458.html
>
> In this topic, Sunil said it was because of the patch added to delay
> dropping of the dentry locks (commit ea455f8ab683) and suggested to fix
> the quota issue in a different way.
> Then you reverted the patches based on Honza's new way to fix the quota
> issue.
> https://oss.oracle.com/pipermail/ocfs2-devel/2014-February/009662.html
>
> I have investigated these patches and still do not know how can it
> happen.
> Could you please tell me more about the case that bits to be cleared
> twice?

I am not sure how the quota patches were related. It was a long time ago.

However, what we fixed in Honza's patches is the way unlink is
performed. The problem was we were getting very bad performance because
of too much of journal activity. We realized that it was because the
inodes were shown as busy and hence moved orphan directory, when they
were not busy. It all came to the point that the open lock was still
being held because it was delayed/offloaded to another thread.

I am not sure, but I guess that this delay may be messing up the
accounting between the node being the owner of the lock and the one
deleting the file (also requesting for the lock). I have not seen this
issue for a long time now so I am not sure. Perhaps Sunil may be able to
give more inputs.


-- 
Goldwyn