search for: memshr_vbd_issue_ro_request

...;'((&vreq->req)->seg[treq.sidx].gref)'' in functions- ''__tapdisk_vbd_complete_td_request'' and ''__tapdisk_vbd_reissue_td_request'' [tapdisk-vbd.c]. I mean, is gref=0 bad? If I keep this condition the control is never transferred to ''memshr_vbd_issue_ro_request'' or ''memshr_vbd_complete_ro_request'' [interface.c] as gref is always 0 everytime I run my DomUs. And if I remove this condition, the check ''(page->count_info != (PGC_allocated | (2 + expected_refcnt)))'' fails in ''page_make_sharable''...

This patch series copies the core of the tapdisk process from blktap2, with updates coming from blktap2.5. Signed-off-by: Thanos Makatos <thanos.makatos@citrix.com>