From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35765) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aW4Eh-0001n8-Pe for qemu-devel@nongnu.org; Wed, 17 Feb 2016 10:41:52 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aW4Eg-0003NC-RU for qemu-devel@nongnu.org; Wed, 17 Feb 2016 10:41:51 -0500 References: <1455646106-2047-1-git-send-email-mreitz@redhat.com> <1455646106-2047-8-git-send-email-mreitz@redhat.com> <20160217105345.GE29494@noname.str.redhat.com> From: Max Reitz Message-ID: <56C494B4.8020707@redhat.com> Date: Wed, 17 Feb 2016 16:41:40 +0100 MIME-Version: 1.0 In-Reply-To: <20160217105345.GE29494@noname.str.redhat.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="DF92DPa8TWP8qTAvfuIqcl9xfKOB1LPdq" Subject: Re: [Qemu-devel] [PATCH v3 07/14] blockdev: Add list of monitor-owned BlockBackends List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kevin Wolf Cc: Stefan Hajnoczi , qemu-devel@nongnu.org, qemu-block@nongnu.org, Markus Armbruster This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --DF92DPa8TWP8qTAvfuIqcl9xfKOB1LPdq Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable On 17.02.2016 11:53, Kevin Wolf wrote: > Am 16.02.2016 um 19:08 hat Max Reitz geschrieben: >> The monitor does hold references to some BlockBackends so it should ha= ve >=20 > s/does hold/holds/? It was intentional, so I'd keep it unless you drop the question mark. >> a list of those BBs; blk_backends is a different list, as it contains >> references to all BBs (after a follow-up patch, that is), and that >> should not be changed because we do need such a list. >> >> monitor_remove_blk() is idempotent so that we can call it in >> blockdev_auto_del() without having to care whether it had been called = in >> do_drive_del() before. monitor_add_blk() is idempotent for symmetry >> reasons (monitor_remove_blk() is, so it would be strange for >> monitor_add_blk() not to be). >> >> Signed-off-by: Max Reitz >=20 > I think hmp_drive_add() needs a monitor_remove_blk() in its error path.= You're right, thanks. In addition, if we really do say that a BB having a name equals being referenced by the monitor, then maybe we don't need explicit calls to monitor_add_blk() because any BB that is created with a non-NULL name should be automatically added to the list of monitor BBs. But that would mean that qemu-img's, qemu-nbd's and qemu-io's BBs would have to be monitor-owned, too, and they'd all have to call monitor_remove_blk() all over the place... Unless we'd allow NULL BB names now and make them use it (I don't really see a reason why not; them calling their BBs "hda" seems weird anyway), or implicitly call monitor_remove_blk() in blk_delete(). Or maybe both, because the latter seems convenient anyway. Max --DF92DPa8TWP8qTAvfuIqcl9xfKOB1LPdq Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAEBCAAGBQJWxJS0AAoJEDuxQgLoOKytwqUH/RETETzc8hEdz2XOMz4NIbAF UXsD5AvYWdDNbVi5EPTTuRJwlexmZbmIG8wLHaHLStYmMc/vi8c6ltrVvj5IxzAB 0H8bVXL92iEniXXa7SNjuZGhKZHfukbRPbf5xwr7M/sSxQqEp4yM7bH2e2M0uHyy obTThKIxYtnVmlUXLB2txY+senVYAwsBrRCNifldyWgHD6f/GO4q60zW+bEwTDy6 9MTBEcQokqdXUqdoOdob8P7jvm8KKE7kcZGs4Fqi2GdAMOqtBrcZtHeYe3Nc9X4z TeI0dKTDF93Etkw3DODgpMQP1SFtwMw30Lx3teeST8B9Barm2NfGsCwYkE/6YBk= =09+G -----END PGP SIGNATURE----- --DF92DPa8TWP8qTAvfuIqcl9xfKOB1LPdq--