From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33135) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dsDIx-0006jH-8m for qemu-devel@nongnu.org; Wed, 13 Sep 2017 15:26:36 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dsDIw-0004t2-6S for qemu-devel@nongnu.org; Wed, 13 Sep 2017 15:26:35 -0400 References: <20170913160333.23622-1-eblake@redhat.com> <20170913160333.23622-22-eblake@redhat.com> From: Eric Blake Message-ID: Date: Wed, 13 Sep 2017 14:26:19 -0500 MIME-Version: 1.0 In-Reply-To: <20170913160333.23622-22-eblake@redhat.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="vU6dL22Hkrx27xjxT4Eq44kkiPxbVKJtE" Subject: Re: [Qemu-devel] [PATCH v4 21/23] block: Align block status requests List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kwolf@redhat.com, famz@redhat.com, qemu-block@nongnu.org, Max Reitz , Stefan Hajnoczi , jsnow@redhat.com This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --vU6dL22Hkrx27xjxT4Eq44kkiPxbVKJtE From: Eric Blake To: qemu-devel@nongnu.org Cc: kwolf@redhat.com, famz@redhat.com, qemu-block@nongnu.org, Max Reitz , Stefan Hajnoczi , jsnow@redhat.com Message-ID: Subject: Re: [Qemu-devel] [PATCH v4 21/23] block: Align block status requests References: <20170913160333.23622-1-eblake@redhat.com> <20170913160333.23622-22-eblake@redhat.com> In-Reply-To: <20170913160333.23622-22-eblake@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 09/13/2017 11:03 AM, Eric Blake wrote: > Any device that has request_alignment greater than 512 should be > unable to report status at a finer granularity; it may also be > simpler for such devices to be guaranteed that the block layer > has rounded things out to the granularity boundary (the way the > block layer already rounds all other I/O out). Besides, getting > the code correct for super-sector alignment also benefits us > for the fact that our public interface now has byte granularity, > even though none of our drivers have byte-level callbacks. >=20 > Add an assertion in blkdebug that proves that the block layer > never requests status of unaligned sections, similar to what it > does on other requests (while still keeping the generic helper > in place for when future patches add a throttle driver). Note > that iotest 177 already covers this (it would fail if you use > just the blkdebug.c hunk without the io.c changes). Meanwhile, > we can drop assertions in callers that no longer have to pass > in sector-aligned addresses. Bummer - 'git bisect' says this patch causes iotests 190 to hang. I'm investigating root cause, but I'll have to post a fixup once I figure it out. --=20 Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org --vU6dL22Hkrx27xjxT4Eq44kkiPxbVKJtE 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/ iQEzBAEBCAAdFiEEccLMIrHEYCkn0vOqp6FrSiUnQ2oFAlm5hlsACgkQp6FrSiUn Q2q/lAf/cnnAHzYPLGgKGUvtfHVbaLJPn9jgm7OS/3uGZxtDHY0kj9RPEIxljUqP w1uhbDKX2jtQfbgahPXXQA9tCGC/s/M5M4qIUkmSAtjy0YrqZLAoGcHOprJbtghR cLKd1Oirp5j8+9HC2mkjmBXCgUU7o39gl6+JcKVPE7YmPqWhz+yaC+9l6zcGMfxx WIzLK2BpIHnj4X3vmsJY3vbgNAwoZkoxs2wNFAIRa82AyuXKeXXTDy1+w/RCNaYD tRFH4+mk+ulFgF4xBI0p96ehgn4Y7RVTN0pF1gKhsc2fDmxEAntEjbsRLHjgpQWJ hXBVmoUKsRWqgAoJ6YCihDmxRanjAw== =mTXH -----END PGP SIGNATURE----- --vU6dL22Hkrx27xjxT4Eq44kkiPxbVKJtE--