From nobody Mon Feb 9 14:34:01 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1492479532312873.3715364636153; Mon, 17 Apr 2017 18:38:52 -0700 (PDT) Received: from localhost ([::1]:39499 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d0I6V-0000FR-0g for importer@patchew.org; Mon, 17 Apr 2017 21:38:51 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33882) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d0I23-00056M-AZ for qemu-devel@nongnu.org; Mon, 17 Apr 2017 21:34:16 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d0I22-0003a7-Ef for qemu-devel@nongnu.org; Mon, 17 Apr 2017 21:34:15 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40064) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1d0I1x-0003Tl-Re; Mon, 17 Apr 2017 21:34:10 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B4DDB81235; Tue, 18 Apr 2017 01:34:08 +0000 (UTC) Received: from red.redhat.com (ovpn-121-102.rdu2.redhat.com [10.10.121.102]) by smtp.corp.redhat.com (Postfix) with ESMTP id C059553C35; Tue, 18 Apr 2017 01:34:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com B4DDB81235 Authentication-Results: ext-mx01.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx01.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=eblake@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com B4DDB81235 From: Eric Blake To: qemu-devel@nongnu.org Date: Mon, 17 Apr 2017 20:33:28 -0500 Message-Id: <20170418013356.3578-4-eblake@redhat.com> In-Reply-To: <20170418013356.3578-1-eblake@redhat.com> References: <20170418013356.3578-1-eblake@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Tue, 18 Apr 2017 01:34:08 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH 03/31] qcow2: Switch is_zero_sectors() to byte-based X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , kwolf@nongnu.org, jsnow@redhat.com, qemu-block@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" We are gradually converting to byte-based interfaces, as they are easier to reason about than sector-based. Convert another internal function (no semantic change), and rename it to is_zero_above() in the process. Signed-off-by: Eric Blake --- block/qcow2.c | 32 ++++++++++++++++++-------------- 1 file changed, 18 insertions(+), 14 deletions(-) diff --git a/block/qcow2.c b/block/qcow2.c index 4d34610..fe4ccf6 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -2442,23 +2442,30 @@ finish: } -static bool is_zero_sectors(BlockDriverState *bs, int64_t start, - uint32_t count) +static bool is_zero_above(BlockDriverState *bs, int64_t offset, int64_t by= tes) { int nr; BlockDriverState *file; int64_t res; + int64_t start; - if (start + count > bs->total_sectors) { - count =3D bs->total_sectors - start; + /* Widen to sector boundaries, then clamp to image length, before + * checking status of underlying sectors */ + start =3D QEMU_ALIGN_DOWN(offset, BDRV_SECTOR_SIZE); + bytes =3D QEMU_ALIGN_UP(offset + bytes, BDRV_SECTOR_SIZE) - start; + + if (start + bytes > bs->total_sectors * BDRV_SECTOR_SIZE) { + bytes =3D bs->total_sectors * BDRV_SECTOR_SIZE - offset; } - if (!count) { + if (!bytes) { return true; } - res =3D bdrv_get_block_status_above(bs, NULL, start, count, + res =3D bdrv_get_block_status_above(bs, NULL, start >> BDRV_SECTOR_BIT= S, + bytes >> BDRV_SECTOR_BITS, &nr, &file); - return res >=3D 0 && (res & BDRV_BLOCK_ZERO) && nr =3D=3D count; + return res >=3D 0 && (res & BDRV_BLOCK_ZERO) && + nr * BDRV_SECTOR_SIZE =3D=3D bytes; } static coroutine_fn int qcow2_co_pwrite_zeroes(BlockDriverState *bs, @@ -2476,24 +2483,21 @@ static coroutine_fn int qcow2_co_pwrite_zeroes(Bloc= kDriverState *bs, } if (head || tail) { - int64_t cl_start =3D (offset - head) >> BDRV_SECTOR_BITS; uint64_t off; unsigned int nr; assert(head + count <=3D s->cluster_size); /* check whether remainder of cluster already reads as zero */ - if (!(is_zero_sectors(bs, cl_start, - DIV_ROUND_UP(head, BDRV_SECTOR_SIZE)) && - is_zero_sectors(bs, (offset + count) >> BDRV_SECTOR_BITS, - DIV_ROUND_UP(-tail & (s->cluster_size - 1), - BDRV_SECTOR_SIZE)))) { + if (!(is_zero_above(bs, offset - head, head) && + is_zero_above(bs, offset + count, + tail ? s->cluster_size - tail : 0))) { return -ENOTSUP; } qemu_co_mutex_lock(&s->lock); /* We can have new write after previous check */ - offset =3D cl_start << BDRV_SECTOR_BITS; + offset =3D QEMU_ALIGN_DOWN(offset, s->cluster_size); count =3D s->cluster_size; nr =3D s->cluster_size; ret =3D qcow2_get_cluster_offset(bs, offset, &nr, &off); --=20 2.9.3