[PATCH 58/71] xfs: garbage collect old cowextsz reservations

[Darrick J. Wong]

On Tue, Sep 27, 2016 at 01:15:01PM -0700, Christoph Hellwig wrote:
> On Mon, Sep 26, 2016 at 02:52:09PM -0700, Darrick J. Wong wrote:
> > On Sat, Sep 24, 2016 at 12:42:34PM -0700, Christoph Hellwig wrote:
> > > On Thu, Aug 25, 2016 at 04:38:14PM -0700, Darrick J. Wong wrote:
> > > > Trim CoW reservations made on behalf of a cowextsz hint if they get too
> > > > old or we run low on quota, so long as we don't have dirty data awaiting
> > > > writeback or directio operations in progress.
> > > 
> > > FYI, at least in your latest tree we only ever seem to set
> > > xfs_inode_set_cowblocks_tag in xfs_swap_extents, so this effectively
> > > isn't used during normal fs usage.
> > 
> > The tag should be set at the end of __xfs_iomap_write_delay if we're
> > creating a DA reservation in the CoW fork. 
> 
> We'll need to add that call then, as your current tree still doesn't
> have it.

Aha, it snuck out the back door during the iomap rewrite. :)

Good catch!

--D