From patchwork Fri Nov 14 13:06:12 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Max Reitz X-Patchwork-Id: 410831 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id AE86D140082 for ; Sat, 15 Nov 2014 00:15:41 +1100 (AEDT) Received: from localhost ([::1]:36453 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XpGix-0007Nw-QP for incoming@patchwork.ozlabs.org; Fri, 14 Nov 2014 08:15:39 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50089) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XpGah-0008RC-B8 for qemu-devel@nongnu.org; Fri, 14 Nov 2014 08:07:13 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XpGab-0003NO-6W for qemu-devel@nongnu.org; Fri, 14 Nov 2014 08:07:07 -0500 Received: from mx1.redhat.com ([209.132.183.28]:58078) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XpGaa-0003NC-Qv for qemu-devel@nongnu.org; Fri, 14 Nov 2014 08:07:01 -0500 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id sAED6uog007452 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 14 Nov 2014 08:06:56 -0500 Received: from localhost (dhcp-192-247.str.redhat.com [10.33.192.247]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id sAED6t0s023037 (version=TLSv1/SSLv3 cipher=AES128-GCM-SHA256 bits=128 verify=NO); Fri, 14 Nov 2014 08:06:56 -0500 From: Max Reitz To: qemu-devel@nongnu.org Date: Fri, 14 Nov 2014 14:06:12 +0100 Message-Id: <1415970374-16811-20-git-send-email-mreitz@redhat.com> In-Reply-To: <1415970374-16811-1-git-send-email-mreitz@redhat.com> References: <1415970374-16811-1-git-send-email-mreitz@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: Kevin Wolf , Peter Lieven , Stefan Hajnoczi , Max Reitz Subject: [Qemu-devel] [PATCH v2 19/21] qcow2: Invoke refcount order amendment function X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Make use of qcow2_change_refcount_order() to support changing the refcount order with qemu-img amend. Signed-off-by: Max Reitz Reviewed-by: Eric Blake --- block/qcow2.c | 44 +++++++++++++++++++++++++++++++++++--------- 1 file changed, 35 insertions(+), 9 deletions(-) diff --git a/block/qcow2.c b/block/qcow2.c index 0263019..469650b 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -2607,13 +2607,7 @@ static int qcow2_downgrade(BlockDriverState *bs, int target_version, } if (s->refcount_order != 4) { - /* we would have to convert the image to a refcount_order == 4 image - * here; however, since qemu (at the time of writing this) does not - * support anything different than 4 anyway, there is no point in doing - * so right now; however, we should error out (if qemu supports this in - * the future and this code has not been adapted) */ - error_report("qcow2_downgrade: Image refcount orders other than 4 are " - "currently not supported."); + error_report("compat=0.10 requires refcount_width=16"); return -ENOTSUP; } @@ -2661,6 +2655,7 @@ typedef enum Qcow2AmendOperation { * invocation from an operation change */ QCOW2_NO_OPERATION = 0, + QCOW2_CHANGING_REFCOUNT_ORDER, QCOW2_DOWNGRADING, } Qcow2AmendOperation; @@ -2736,6 +2731,7 @@ static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts, const char *compat = NULL; uint64_t cluster_size = s->cluster_size; bool encrypt; + int refcount_width = s->refcount_bits; int ret; QemuOptDesc *desc = opts->list->desc; Qcow2AmendHelperCBInfo helper_cb_info; @@ -2785,8 +2781,16 @@ static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts, lazy_refcounts = qemu_opt_get_bool(opts, "lazy_refcounts", lazy_refcounts); } else if (!strcmp(desc->name, "refcount_width")) { - error_report("Cannot change refcount entry width"); - return -ENOTSUP; + refcount_width = qemu_opt_get_number(opts, "refcount_width", + refcount_width); + + if (refcount_width <= 0 || refcount_width > 64 || + !is_power_of_2(refcount_width)) + { + error_report("Refcount width must be a power of two and may " + "not exceed 64 bits"); + return -EINVAL; + } } else { /* if this point is reached, this probably means a new option was * added without having it covered here */ @@ -2800,6 +2804,7 @@ static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts, .original_status_cb = status_cb, .original_cb_opaque = cb_opaque, .total_operations = (new_version < old_version) + + (s->refcount_bits != refcount_width) }; /* Upgrade first (some features may require compat=1.1) */ @@ -2812,6 +2817,27 @@ static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts, } } + if (s->refcount_bits != refcount_width) { + int refcount_order = ffs(refcount_width) - 1; + Error *local_error = NULL; + + if (new_version < 3 && refcount_width != 16) { + error_report("Different refcount widths than 16 bits require " + "compatibility level 1.1 or above (use compat=1.1 or " + "greater)"); + return -EINVAL; + } + + helper_cb_info.current_operation = QCOW2_CHANGING_REFCOUNT_ORDER; + ret = qcow2_change_refcount_order(bs, refcount_order, + &qcow2_amend_helper_cb, + &helper_cb_info, &local_error); + if (ret < 0) { + qerror_report_err(local_error); + return ret; + } + } + if (backing_file || backing_format) { ret = qcow2_change_backing_file(bs, backing_file ?: bs->backing_file, backing_format ?: bs->backing_format);