From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42063) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ebY5K-00036n-Qy for qemu-devel@nongnu.org; Tue, 16 Jan 2018 15:43:55 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ebY5J-0002SG-UV for qemu-devel@nongnu.org; Tue, 16 Jan 2018 15:43:54 -0500 References: <1516107870-8110-1-git-send-email-anton.nefedov@virtuozzo.com> <1516107870-8110-5-git-send-email-anton.nefedov@virtuozzo.com> From: Eric Blake Message-ID: <45a18aa0-113b-a87e-39ee-97beb205c922@redhat.com> Date: Tue, 16 Jan 2018 14:43:28 -0600 MIME-Version: 1.0 In-Reply-To: <1516107870-8110-5-git-send-email-anton.nefedov@virtuozzo.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="nDIlh0zswpni3gKFb7CizEITdFEZSBw3N" Subject: Re: [Qemu-devel] [PATCH v6 4/9] block: treat BDRV_REQ_ALLOCATE as serialising List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anton Nefedov , qemu-devel@nongnu.org Cc: qemu-block@nongnu.org, kwolf@redhat.com, mreitz@redhat.com, den@virtuozzo.com, berto@igalia.com This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --nDIlh0zswpni3gKFb7CizEITdFEZSBw3N From: Eric Blake To: Anton Nefedov , qemu-devel@nongnu.org Cc: qemu-block@nongnu.org, kwolf@redhat.com, mreitz@redhat.com, den@virtuozzo.com, berto@igalia.com Message-ID: <45a18aa0-113b-a87e-39ee-97beb205c922@redhat.com> Subject: Re: [PATCH v6 4/9] block: treat BDRV_REQ_ALLOCATE as serialising References: <1516107870-8110-1-git-send-email-anton.nefedov@virtuozzo.com> <1516107870-8110-5-git-send-email-anton.nefedov@virtuozzo.com> In-Reply-To: <1516107870-8110-5-git-send-email-anton.nefedov@virtuozzo.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 01/16/2018 07:04 AM, Anton Nefedov wrote: > The idea is that ALLOCATE requests may overlap with other requests. > Reuse the existing block layer infrastructure for serialising requests.= > Use the following approach: > - mark ALLOCATE serialising, so subsequent requests to the area wait > - ALLOCATE request itself must never wait if another request is in fl= ight > already. Return EAGAIN, let the caller reconsider. >=20 > Signed-off-by: Anton Nefedov > --- > block/io.c | 27 +++++++++++++++++++-------- > 1 file changed, 19 insertions(+), 8 deletions(-) >=20 Reviewed-by: Eric Blake --=20 Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org --nDIlh0zswpni3gKFb7CizEITdFEZSBw3N 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/ iQEzBAEBCAAdFiEEccLMIrHEYCkn0vOqp6FrSiUnQ2oFAlpeY/AACgkQp6FrSiUn Q2pvwwf9HfSDCQ9EQ8pb7wRKHujLpIpH2e6XiPTrQbN4ckQ5QBWpCsk3NeJ3WhPd RcCzp2OBdOOk9Ak8XiQqza7aXDffGXY0Ar1r2ggrmfCGUhAt8BWPkS+Vxxd4qguI bKlUaCyGO/InhHZs3b/2TijOMbkc2RRNtZGYB/ddXpkhwRpLLtY9fCG1C0Aecnjq 4vdAMKcbVgErXQOaaVqidRKh7lhpMZTiQlldleNoAy0JH3AnKEprd8lZKutcaFzH b24YaaaRvQ9xp0GEPU5h8VSRn65Rg3Dp/kiPHsflW4/DaLOsTPUVKiGa3AUQW9ZI zYKF8TXUbY5nZL478txC1VXT8VtpQQ== =N3Zl -----END PGP SIGNATURE----- --nDIlh0zswpni3gKFb7CizEITdFEZSBw3N--