From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34765) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1evMTP-0000Ip-2j for qemu-devel@nongnu.org; Mon, 12 Mar 2018 08:22:40 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1evMTN-0002Vw-VH for qemu-devel@nongnu.org; Mon, 12 Mar 2018 08:22:39 -0400 References: <20180224154033.29559-1-mreitz@redhat.com> <1d3b01d0-4cf8-9a3a-e7a6-862599cda2dc@redhat.com> From: Max Reitz Message-ID: <448e14c2-98c6-245d-d1af-a84743656bc7@redhat.com> Date: Mon, 12 Mar 2018 13:22:29 +0100 MIME-Version: 1.0 In-Reply-To: <1d3b01d0-4cf8-9a3a-e7a6-862599cda2dc@redhat.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="S6n229cyNuNOTT4q6cvhrWtpOCusVpOSk" Subject: Re: [Qemu-devel] [PATCH v3 0/7] block: Handle null backing link List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Blake , qemu-block@nongnu.org Cc: qemu-devel@nongnu.org, Markus Armbruster , Alberto Garcia , Michael Roth This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --S6n229cyNuNOTT4q6cvhrWtpOCusVpOSk From: Max Reitz To: Eric Blake , qemu-block@nongnu.org Cc: qemu-devel@nongnu.org, Markus Armbruster , Alberto Garcia , Michael Roth Message-ID: <448e14c2-98c6-245d-d1af-a84743656bc7@redhat.com> Subject: Re: [PATCH v3 0/7] block: Handle null backing link References: <20180224154033.29559-1-mreitz@redhat.com> <1d3b01d0-4cf8-9a3a-e7a6-862599cda2dc@redhat.com> In-Reply-To: <1d3b01d0-4cf8-9a3a-e7a6-862599cda2dc@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 2018-03-10 23:34, Eric Blake wrote: > On 02/24/2018 09:40 AM, Max Reitz wrote: >> Currently, we try to rewrite every occurrence of "backing": null into >> "backing": "" in qmp_blockdev_add().=C2=A0 However, that breaks using = the >> same "backing": null construction in json:{} file names (which do not = go >> through qmp_blockdev_add()).=C2=A0 Currently, these then just behave a= s if >> the option has not been specified. >> >> Since there is actually only one place where we evaluate the @backing >> option to find out whether not to use a backing file, we can instead >> just check for null there.=C2=A0 It doesn't matter that this changes t= he >> runtime state of the option from "" to null, because nobody really doe= s >> anything with that runtime state anyway (except put it into qemu again= , >> but qemu doesn't care whether it's "" or null). >> >> And in the future, it's much better if we get it to be null in that >> runtime state sooner than later -- see patch 7. >> >> >> Note that it was Markus (who's away having a good time, I hope) who >> proposed qobject_to(), so I guess he won't object too much to seeing t= he >> concept having landed in his tree once he returns. >> (Although he hasn't reviewed the previous iteration of this series, >> =C2=A0 which included it already.) >> >=20 > Thanks, applied to my QAPI staging tree (with qobject_to(type, obj) > reordering - it didn't take me too long after all): > git://repo.or.cz/qemu/ericb.git qapi > http://repo.or.cz/qemu/ericb.git/shortlog/refs/heads/qapi Thanks! Max --S6n229cyNuNOTT4q6cvhrWtpOCusVpOSk Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQFGBAEBCAAwFiEEkb62CjDbPohX0Rgp9AfbAGHVz0AFAlqmcQUSHG1yZWl0ekBy ZWRoYXQuY29tAAoJEPQH2wBh1c9AHugIALnCzHAKhBwz7Y6LtcQmSKKlKS6QI3T6 3f9Hm+U/5SWIwMUGS/zbUcKL/xloiDS1AyJ/6kjtAj1+mhfx1b6lZ55qGvHaF49t LUPn5jPuf6fBb3Fv2DP25iw3tAmQHDJ6vpFugxvvZ3P+4p63A3B/Gz8e1/Wg8aEl 2C7EeIQ39oEYCgETFOe9ZS9Tp81OtQJsi6ccfTY6UaL+IpFA4KnecIB9z6ML+sK4 7B9Rf08fQ7fGlOhiwkgryukQVoPxEsvU6vR4xqt1GEFhZsYwrOpOzWBU2hHpBgtu y6pQzvEvizhcqT3Fg/nkoYEZPtE2ZVh+Ti/pqUYpVKeLxgwpltNF4bg= =Y8AA -----END PGP SIGNATURE----- --S6n229cyNuNOTT4q6cvhrWtpOCusVpOSk--