From patchwork Thu Apr 23 15:01:21 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 284009 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5C6F6C54FD0 for ; Thu, 23 Apr 2020 15:07:03 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2258520857 for ; Thu, 23 Apr 2020 15:07:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="JR2C35Qf" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2258520857 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:45176 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jRdRO-0004II-6B for qemu-devel@archiver.kernel.org; Thu, 23 Apr 2020 11:07:02 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:40972) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jRdMQ-00052W-ST for qemu-devel@nongnu.org; Thu, 23 Apr 2020 11:01:58 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.90_1) (envelope-from ) id 1jRdMO-0005fD-GY for qemu-devel@nongnu.org; Thu, 23 Apr 2020 11:01:54 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:46469 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jRdMN-0005cB-IL for qemu-devel@nongnu.org; Thu, 23 Apr 2020 11:01:51 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1587654108; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=fSzpbwFqcetssAHV7O9Qdmxy1jcL+ITFbiKVQpjaoHo=; b=JR2C35Qf4i2ywxhJySU1ISu2QG/UM98NaaZHo9ZAdZN6bJAQWqoxG03yqAWiuLILJ1mfzQ FpeI3GrBN5GoZvKAmTcXDu06z2cP5vIi90IEhbBAiqdy1EXwih1zuQVJ7oL1FIQJY3kCoS MT0Q81aCJVgd7TEWPpcsvkNKvPrVOqU= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-444-NyWkPPTyNHKQf5K4sLl5Fg-1; Thu, 23 Apr 2020 11:01:46 -0400 X-MC-Unique: NyWkPPTyNHKQf5K4sLl5Fg-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 51528800FC7; Thu, 23 Apr 2020 15:01:45 +0000 (UTC) Received: from linux.fritz.box.com (ovpn-114-28.ams2.redhat.com [10.36.114.28]) by smtp.corp.redhat.com (Postfix) with ESMTP id A870660C81; Thu, 23 Apr 2020 15:01:43 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Subject: [PATCH v6 04/10] qcow2: Support BDRV_REQ_ZERO_WRITE for truncate Date: Thu, 23 Apr 2020 17:01:21 +0200 Message-Id: <20200423150127.142609-5-kwolf@redhat.com> In-Reply-To: <20200423150127.142609-1-kwolf@redhat.com> References: <20200423150127.142609-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=205.139.110.61; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/04/23 03:23:21 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] X-Received-From: 205.139.110.61 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, vsementsov@virtuozzo.com, berto@igalia.com, qemu-devel@nongnu.org, mreitz@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" If BDRV_REQ_ZERO_WRITE is set and we're extending the image, calling qcow2_cluster_zeroize() with flags=0 does the right thing: It doesn't undo any previous preallocation, but just adds the zero flag to all relevant L2 entries. If an external data file is in use, a write_zeroes request to the data file is made instead. Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz --- block/qcow2-cluster.c | 2 +- block/qcow2.c | 33 +++++++++++++++++++++++++++++++++ 2 files changed, 34 insertions(+), 1 deletion(-) diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index 17f1363279..4b5fc8c4a7 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -1795,7 +1795,7 @@ int qcow2_cluster_zeroize(BlockDriverState *bs, uint64_t offset, /* Caller must pass aligned values, except at image end */ assert(QEMU_IS_ALIGNED(offset, s->cluster_size)); assert(QEMU_IS_ALIGNED(end_offset, s->cluster_size) || - end_offset == bs->total_sectors << BDRV_SECTOR_BITS); + end_offset >= bs->total_sectors << BDRV_SECTOR_BITS); /* The zero flag is only supported by version 3 and newer */ if (s->qcow_version < 3) { diff --git a/block/qcow2.c b/block/qcow2.c index 9cfbdfc939..ad621fe404 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -1726,6 +1726,7 @@ static int coroutine_fn qcow2_do_open(BlockDriverState *bs, QDict *options, bs->supported_zero_flags = header.version >= 3 ? BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK : 0; + bs->supported_truncate_flags = BDRV_REQ_ZERO_WRITE; /* Repair image if dirty */ if (!(flags & (BDRV_O_CHECK | BDRV_O_INACTIVE)) && !bs->read_only && @@ -4214,6 +4215,38 @@ static int coroutine_fn qcow2_co_truncate(BlockDriverState *bs, int64_t offset, g_assert_not_reached(); } + if ((flags & BDRV_REQ_ZERO_WRITE) && offset > old_length) { + uint64_t zero_start = QEMU_ALIGN_UP(old_length, s->cluster_size); + + /* + * Use zero clusters as much as we can. qcow2_cluster_zeroize() + * requires a cluster-aligned start. The end may be unaligned if it is + * at the end of the image (which it is here). + */ + ret = qcow2_cluster_zeroize(bs, zero_start, offset - zero_start, 0); + if (ret < 0) { + error_setg_errno(errp, -ret, "Failed to zero out new clusters"); + goto fail; + } + + /* Write explicit zeros for the unaligned head */ + if (zero_start > old_length) { + uint8_t *buf = qemu_blockalign0(bs, s->cluster_size); + QEMUIOVector qiov; + qemu_iovec_init_buf(&qiov, buf, zero_start - old_length); + + qemu_co_mutex_unlock(&s->lock); + ret = qcow2_co_pwritev_part(bs, old_length, qiov.size, &qiov, 0, 0); + qemu_co_mutex_lock(&s->lock); + + qemu_vfree(buf); + if (ret < 0) { + error_setg_errno(errp, -ret, "Failed to zero out the new area"); + goto fail; + } + } + } + if (prealloc != PREALLOC_MODE_OFF) { /* Flush metadata before actually changing the image size */ ret = qcow2_write_caches(bs);