From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56679) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f8q5t-0001gG-BT for qemu-devel@nongnu.org; Wed, 18 Apr 2018 12:38:07 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1f8q5s-0001dK-Bp for qemu-devel@nongnu.org; Wed, 18 Apr 2018 12:38:05 -0400 References: <20180413143156.11409-1-vsementsov@virtuozzo.com> From: Eric Blake Message-ID: <461d56f3-4381-4cd6-f66d-1dd510c35fa8@redhat.com> Date: Wed, 18 Apr 2018 11:37:58 -0500 MIME-Version: 1.0 In-Reply-To: <20180413143156.11409-1-vsementsov@virtuozzo.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="wNFogd4faKh9fixph79vwXk82t5I1GaZN" Subject: Re: [Qemu-devel] [PATCH] nbd/server: introduce NBD_CMD_CACHE List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Vladimir Sementsov-Ogievskiy , qemu-devel@nongnu.org, qemu-block@nongnu.org Cc: mreitz@redhat.com, kwolf@redhat.com, den@openvz.org, pbonzini@redhat.com This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --wNFogd4faKh9fixph79vwXk82t5I1GaZN From: Eric Blake To: Vladimir Sementsov-Ogievskiy , qemu-devel@nongnu.org, qemu-block@nongnu.org Cc: mreitz@redhat.com, kwolf@redhat.com, den@openvz.org, pbonzini@redhat.com Message-ID: <461d56f3-4381-4cd6-f66d-1dd510c35fa8@redhat.com> Subject: Re: [PATCH] nbd/server: introduce NBD_CMD_CACHE References: <20180413143156.11409-1-vsementsov@virtuozzo.com> In-Reply-To: <20180413143156.11409-1-vsementsov@virtuozzo.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 04/13/2018 09:31 AM, Vladimir Sementsov-Ogievskiy wrote: > Handle nbd CACHE command. Just do read, without sending read data back.= > Cache mechanism should be done by exported node driver chain. >=20 > Signed-off-by: Vladimir Sementsov-Ogievskiy > --- > include/block/nbd.h | 3 ++- > nbd/server.c | 10 ++++++---- > 2 files changed, 8 insertions(+), 5 deletions(-) >=20 > diff --git a/include/block/nbd.h b/include/block/nbd.h > index fcdcd54502..b4793d0a29 100644 > --- a/include/block/nbd.h > +++ b/include/block/nbd.h > @@ -135,6 +135,7 @@ typedef struct NBDExtent { > #define NBD_FLAG_SEND_TRIM (1 << 5) /* Send TRIM (discard) */ > #define NBD_FLAG_SEND_WRITE_ZEROES (1 << 6) /* Send WRITE_ZEROES */ > #define NBD_FLAG_SEND_DF (1 << 7) /* Send DF (Do not Fragmen= t) */ > +#define NBD_FLAG_SEND_CACHE (1 << 8) /* Send CACHE (prefetch) *= / Hmm, this flag is not documented in the upstream NBD protocol yet; are we sure it matches the xNBD implementation? We'll want at least a documentation patch proposed for the NBD list before taking this. --=20 Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org --wNFogd4faKh9fixph79vwXk82t5I1GaZN Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Comment: Public key at http://people.redhat.com/eblake/eblake.gpg Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEzBAEBCAAdFiEEccLMIrHEYCkn0vOqp6FrSiUnQ2oFAlrXdGYACgkQp6FrSiUn Q2rgBgf+Kvio5uHx62e1ZAlEZW6fhnL6gcHFMPPOGggEamrKhQ/BUb1o4oHC4E91 NeUiVdbuionSA7cDHvBmmZSAfXRcqVdo7e9c6pt06wuwa3BJLHnGg7K0XK1y0JOx lP20CchQxwHNOxrBKUt3F/Nb/IznvPKCOKbpgnFiYp6ZLvwbDG8kooscz1GNYna/ 0cfAfcXOmdZf7K2Z1OSQ4/zgnvQmPA62LpySqsOzDzxB04KlsjQNNvFVd3PmELsb Zw2JhNkRvIbpo/nd64a44a6Z6dnnP5JRUl2PRTXDZNV7bXYYMnISSsIrRvSbNxmJ OwCCA0WD7R5S1mu12tp8RbmAoGlahw== =rLjL -----END PGP SIGNATURE----- --wNFogd4faKh9fixph79vwXk82t5I1GaZN--