Re: Review: Fix dbflush panic in xfs_qm_sync

Christoph Hellwig
2007-10-18T16:16:12Z

On Tue, Oct 16, 2007 at 09:29:23AM +1000, Donald Douwsma wrote:
> The recent behaviour layer removal dropped the check for quotas that have
> been
> requested at mount time but have subsequently been turned off. This results
> in a panic when accessing m_quotainfo which has been freed.
>
> This patch adds the check originally made by xfs_qm_syncall() to
> xfs_qm_sync()

Hmm. We do the same check just a few lines below, but inbetween
we access ->m_quotainfo to take the lock. I was under the impression
that's the only safe way to check anyway, but ->m_quotainfo might not
actually be present. It might me better to move the lock into xfs_mount
directly, but it's embedded into a xfs_dqhash and there's some complex
mess with gazillions of macros around it.

So I suspect restoring it to the original state might be good enough.