From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35762) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1faiT5-0003NI-Co for qemu-devel@nongnu.org; Wed, 04 Jul 2018 10:09:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1faiT4-0003Al-Ex for qemu-devel@nongnu.org; Wed, 04 Jul 2018 10:09:15 -0400 References: <20180702025836.20957-1-famz@redhat.com> <02d1f79b-c055-bb2a-edd5-3429ff64af90@redhat.com> <20180703012626.GB485@lemon.usersys.redhat.com> From: Max Reitz Message-ID: Date: Wed, 4 Jul 2018 16:09:04 +0200 MIME-Version: 1.0 In-Reply-To: <20180703012626.GB485@lemon.usersys.redhat.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="CIA6RBFzzO5G7xNj3NjhivydGSToU6TWD" Subject: Re: [Qemu-devel] [PATCH 0/4] block: Trivial fixes in offloading code List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Fam Zheng Cc: qemu-devel@nongnu.org, Kevin Wolf , qemu-block@nongnu.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --CIA6RBFzzO5G7xNj3NjhivydGSToU6TWD From: Max Reitz To: Fam Zheng Cc: qemu-devel@nongnu.org, Kevin Wolf , qemu-block@nongnu.org Message-ID: Subject: Re: [PATCH 0/4] block: Trivial fixes in offloading code References: <20180702025836.20957-1-famz@redhat.com> <02d1f79b-c055-bb2a-edd5-3429ff64af90@redhat.com> <20180703012626.GB485@lemon.usersys.redhat.com> In-Reply-To: <20180703012626.GB485@lemon.usersys.redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 2018-07-03 03:26, Fam Zheng wrote: > On Mon, 07/02 14:35, Max Reitz wrote: >> On 2018-07-02 04:58, Fam Zheng wrote: >>> These are the low priority ones spotted by Kevin and Max last week. >>> >>> Fam Zheng (4): >>> qcow2: Drop unused cluster_data >>> file-posix: Fix fd_open check in raw_co_copy_range_to >>> qcow2: Drop unreachable break >>> raw: Drop superfluous semicolon >>> >>> block/file-posix.c | 2 +- >>> block/qcow2.c | 3 --- >>> block/raw-format.c | 2 +- >>> 3 files changed, 2 insertions(+), 5 deletions(-) >> >> Thanks, applied to my block branch: >> >> https://git.xanclic.moe/XanClic/qemu/commits/branch/block >> >> >> Do you want to make qcow2_co_copy_range_to() do something special on >> BDRV_REQ_ZERO_WRITE? To me, it seems natural, but on the other hand >> maybe it wouldn't bring anything. If the protocol layer supports copy= >> offloading, then it'll probably do that zero write efficiently anyway.= >> If it doesn't, qemu-img convert will just fall back to the usual >> implementation which involves writing zeroes when zeroes are read, so.= =2E. >> What's your opinion? >=20 > In bdrv_co_copy_range_internal() there is >=20 > if (flags & BDRV_REQ_ZERO_WRITE) { > return bdrv_co_pwrite_zeroes(dst, dst_offset, bytes, flags); > } >=20 > before calling driver .bdrv_co_copy_range_to() callback. I think this i= s enough? Ah, right... Yep, that's enough. :-) Max --CIA6RBFzzO5G7xNj3NjhivydGSToU6TWD Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEkb62CjDbPohX0Rgp9AfbAGHVz0AFAls81QAACgkQ9AfbAGHV z0AYxQgAnVic2zMkW94JnGzo2lFmgB74zOmSYtY9t+yLIn+smhc8hkhjZBv8Nj1O PvOB/VLucMmfapdDQtoDnblFWxlDjN3w5n8Z6usl4cnbvqvC0dHhzqOu8sL2ZOq/ nyTnlMc/GuNAU0kx38gsXC9qohFh4pkjDKx+/lE0LPZyWo4XK1mu+86gxDPOQkAE bBQhIbDwVdXmPC6igUs23aytA1SoAN0F274r2OA/EP/vkv/yIMuethmOZPpDyJ3I EkC/7LGxgpR2ECgyROWKRV1LMj9u4U3X3te25h8uWwx+Slx9hQ8oSrgEF8dvJ3lc yILF41cknIoKZQl5oird7m3qF/XlNQ== =l/qL -----END PGP SIGNATURE----- --CIA6RBFzzO5G7xNj3NjhivydGSToU6TWD--