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Wed, 11 Sep 2019 06:21:51 +0000 (UTC) Received: from dresden.str.redhat.com (ovpn-116-94.ams2.redhat.com [10.36.116.94]) by smtp.corp.redhat.com (Postfix) with ESMTPS id A67E65C21E; Wed, 11 Sep 2019 06:21:49 +0000 (UTC) To: Kevin Wolf References: <20190809161407.11920-1-mreitz@redhat.com> <20190809161407.11920-24-mreitz@redhat.com> <20190910150241.GJ4446@localhost.localdomain> From: Max Reitz Openpgp: preference=signencrypt Autocrypt: addr=mreitz@redhat.com; prefer-encrypt=mutual; keydata= mQENBFXOJlcBCADEyyhOTsoa/2ujoTRAJj4MKA21dkxxELVj3cuILpLTmtachWj7QW+TVG8U /PsMCFbpwsQR7oEy8eHHZwuGQsNpEtNC2G/L8Yka0BIBzv7dEgrPzIu+W3anZXQW4702+uES U29G8TP/NGfXRRHGlbBIH9KNUnOSUD2vRtpOLXkWsV5CN6vQFYgQfFvmp5ZpPeUe6xNplu8V mcTw8OSEDW/ZnxJc8TekCKZSpdzYoxfzjm7xGmZqB18VFwgJZlIibt1HE0EB4w5GsD7x5ekh awIe3RwoZgZDLQMdOitJ1tUc8aqaxvgA4tz6J6st8D8pS//m1gAoYJWGwwIVj1DjTYLtABEB AAG0HU1heCBSZWl0eiA8bXJlaXR6QHJlZGhhdC5jb20+iQFTBBMBCAA9AhsDBQkSzAMABQsJ CAcCBhUICQoLAgQWAgMBAh4BAheABQJVzie5FRhoa3A6Ly9rZXlzLmdudXBnLm5ldAAKCRD0 B9sAYdXPQDcIB/9uNkbYEex1rHKz3mr12uxYMwLOOFY9fstP5aoVJQ1nWQVB6m2cfKGdcRe1 2/nFaHSNAzT0NnKz2MjhZVmcrpyd2Gp2QyISCfb1FbT82GMtXFj1wiHmPb3CixYmWGQUUh+I AvUqsevLA+WihgBUyaJq/vuDVM1/K9Un+w+Tz5vpeMidlIsTYhcsMhn0L9wlCjoucljvbDy/ 8C9L2DUdgi3XTa0ORKeflUhdL4gucWoAMrKX2nmPjBMKLgU7WLBc8AtV+84b9OWFML6NEyo4 4cP7cM/07VlJK53pqNg5cHtnWwjHcbpGkQvx6RUx6F1My3y52vM24rNUA3+ligVEgPYBuQEN BFXOJlcBCADAmcVUNTWT6yLWQHvxZ0o47KCP8OcLqD+67T0RCe6d0LP8GsWtrJdeDIQk+T+F xO7DolQPS6iQ6Ak2/lJaPX8L0BkEAiMuLCKFU6Bn3lFOkrQeKp3u05wCSV1iKnhg0UPji9V2 W5eNfy8F4ZQHpeGUGy+liGXlxqkeRVhLyevUqfU0WgNqAJpfhHSGpBgihUupmyUg7lfUPeRM DzAN1pIqoFuxnN+BRHdAecpsLcbR8sQddXmDg9BpSKozO/JyBmaS1RlquI8HERQoe6EynJhd 64aICHDfj61rp+/0jTIcevxIIAzW70IadoS/y3DVIkuhncgDBvGbF3aBtjrJVP+5ABEBAAGJ ASUEGAEIAA8FAlXOJlcCGwwFCRLMAwAACgkQ9AfbAGHVz0CbFwf9F/PXxQR9i4N0iipISYjU sxVdjJOM2TMut+ZZcQ6NSMvhZ0ogQxJ+iEQ5OjnIputKvPVd5U7WRh+4lF1lB/NQGrGZQ1ic alkj6ocscQyFwfib+xIe9w8TG1CVGkII7+TbS5pXHRxZH1niaRpoi/hYtgzkuOPp35jJyqT/ /ELbqQTDAWcqtJhzxKLE/ugcOMK520dJDeb6x2xVES+S5LXby0D4juZlvUj+1fwZu+7Io5+B bkhSVPb/QdOVTpnz7zWNyNw+OONo1aBUKkhq2UIByYXgORPFnbfMY7QWHcjpBVw9MgC4tGeF R4bv+1nAMMxKmb5VvQCExr0eFhJUAHAhVg== Message-ID: Date: Wed, 11 Sep 2019 08:21:47 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190910150241.GJ4446@localhost.localdomain> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="myHKyDAxXlc4PcvsFb4SFoMxmtGn4Aud7" X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.45]); Wed, 11 Sep 2019 06:21:51 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [PATCH v6 23/42] blockdev: Use CAF in external_snapshot_prepare() X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Vladimir Sementsov-Ogievskiy , qemu-devel@nongnu.org, qemu-block@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --myHKyDAxXlc4PcvsFb4SFoMxmtGn4Aud7 Content-Type: multipart/mixed; boundary="p9PtTpMyHYC89agw1KAShYkZ4YPpKE9lX"; protected-headers="v1" From: Max Reitz To: Kevin Wolf Cc: qemu-block@nongnu.org, qemu-devel@nongnu.org, Vladimir Sementsov-Ogievskiy Message-ID: Subject: Re: [PATCH v6 23/42] blockdev: Use CAF in external_snapshot_prepare() References: <20190809161407.11920-1-mreitz@redhat.com> <20190809161407.11920-24-mreitz@redhat.com> <20190910150241.GJ4446@localhost.localdomain> In-Reply-To: <20190910150241.GJ4446@localhost.localdomain> --p9PtTpMyHYC89agw1KAShYkZ4YPpKE9lX Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 10.09.19 17:02, Kevin Wolf wrote: > Am 09.08.2019 um 18:13 hat Max Reitz geschrieben: >> This allows us to differentiate between filters and nodes with COW >> backing files: Filters cannot be used as overlays at all (for this >> function). >> >> Signed-off-by: Max Reitz >> Reviewed-by: Vladimir Sementsov-Ogievskiy >=20 > Didn't we occasionally advertise blockdev-snapshot as the way to insert= > filters on top at runtime? I can only remember advertising for it as the only graph manipulation tool we had, and maybe saying =E2=80=9CWe=E2=80=99d want something like blockdev-snapshot for filters, too=E2=80=9D. Max > Though it seems it has always only worked for > filters that use bs->backing, among which I think there aren't any > user-creatable ones. So we're probably good. >=20 > Kevin >=20 >> blockdev.c | 7 ++++++- >> 1 file changed, 6 insertions(+), 1 deletion(-) >> >> diff --git a/blockdev.c b/blockdev.c >> index 29c6c6044a..c540802127 100644 >> --- a/blockdev.c >> +++ b/blockdev.c >> @@ -1664,7 +1664,12 @@ static void external_snapshot_prepare(BlkAction= State *common, >> goto out; >> } >> =20 >> - if (state->new_bs->backing !=3D NULL) { >> + if (state->new_bs->drv->is_filter) { >> + error_setg(errp, "Filters cannot be used as overlays"); >> + goto out; >> + } >> + >> + if (bdrv_filtered_cow_child(state->new_bs)) { >> error_setg(errp, "The overlay already has a backing image"); >> goto out; >> } >> --=20 >> 2.21.0 >> --p9PtTpMyHYC89agw1KAShYkZ4YPpKE9lX-- --myHKyDAxXlc4PcvsFb4SFoMxmtGn4Aud7 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEkb62CjDbPohX0Rgp9AfbAGHVz0AFAl14knsACgkQ9AfbAGHV z0DJ/wgAj/B3q2kDwaM72wGdtSLE2FWURyQ482/hODFJQglq9IqiXXy/AWKtKqoR /bylE8EyxR1bv180klhOLwDmp2+QT+fkxnqPBQkxT6xCNVZuyJ8XT2gRk7hovtGL Stj4elBG+CvedeuAkzRgU/RMwcw0VzZltUWiv028nSfVACddhkJ40+x8WXglf4w8 dGtQHuBXjhsBp1rieGuOpzIV9l6q24lT6S63sBF3qIQf1wCuAVn6ESKD9zX7S8TQ Rv2IXEW21dKRxyzdZD+eYRKBgE2on2sl4rAHXy9vgS7XVU679AvcQvRJ/5SndOXM NCERc5TJLdlNGgw0HwLEdM50t896fA== =/qrC -----END PGP SIGNATURE----- --myHKyDAxXlc4PcvsFb4SFoMxmtGn4Aud7--