On Wed, Sep 18, 2019 at 10:26:17AM -0700, Darrick J. Wong wrote: > Hmm. At first I thought this was a behavior change but I think it isn't > because prior to this patch we'd set cmap = imap and if _allocate_cow > didn't find a shared extent then it would just return without doing > anything or touching cmap. In the !shared case this would just set imap > to itself pointlessly. > > Now that we pass both imap and cmap to _allocate_cow, in the !shared > case we don't initialized cmap at all, so adding the @shared check is > required for correct operation, right? Exactly.