From mboxrd@z Thu Jan 1 00:00:00 1970 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=-17.0 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 AC760C433F5 for ; Tue, 14 Sep 2021 08:57:22 +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 368BD610D1 for ; Tue, 14 Sep 2021 08:57:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 368BD610D1 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:40252 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mQ4Fl-0000Dh-EQ for qemu-devel@archiver.kernel.org; Tue, 14 Sep 2021 04:57:21 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:59908) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mQ4D7-0005J8-R5 for qemu-devel@nongnu.org; Tue, 14 Sep 2021 04:54:39 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:50611) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mQ4D3-0000sx-Tq for qemu-devel@nongnu.org; Tue, 14 Sep 2021 04:54:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1631609672; 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=GKTbNZ3gWKTTBNqqb81VtQvASTcP/qe7/2shVDcWhQA=; b=C+/aXN7yphYpaYKPoV9xG5KzrrDuhkaon/Pop6vz3pO5YVAbqjx0r7O/u+ZwNs3xi1+mJ7 Zt6FE+w9tNtcYW4il+wnEDLl4WHhynCQ3RTF/i7rd2UwnWdB2FLWAF0GviYdArqKq65I6L nyaHnKRO0Q8LehixLBb5wNxXvieXK+k= Received: from mail-wr1-f69.google.com (mail-wr1-f69.google.com [209.85.221.69]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-158-HFYj9WIBO7aC6rsKjn5FQA-1; Tue, 14 Sep 2021 04:54:31 -0400 X-MC-Unique: HFYj9WIBO7aC6rsKjn5FQA-1 Received: by mail-wr1-f69.google.com with SMTP id z2-20020a5d4c82000000b0015b140e0562so3702171wrs.7 for ; Tue, 14 Sep 2021 01:54:31 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=GKTbNZ3gWKTTBNqqb81VtQvASTcP/qe7/2shVDcWhQA=; b=UkQdVYltX78Sa57hLVC/KZAjuUbF6C0+Nsx8Y9fd0pryc0Esgw+VZDme0wANqNU15T GfPAt5YzAFuE4ByNCZ1NbB76DYh0WCpmLVfaVQ/yZikD693JzPFMJlQlFhtxZOm27YvS ru9Z4HZVXk3FEjePK4KmR0+glSX6jZhTeqlyGIw9WaFG3YgK5hziNxrzJGLBTyxXOGkL eO0UBZDLjLo+pphUaYNeSZosJhvv+OkbaMmpm+JTxjPcVvM6kmBm6OOCdkPnUeB6CQjq Jr4Qk0gdN+YThgcIPaPXhO0e0zF9CSEjK6A7iomuqyJmLz6NIHARxsRUHAWmC20HdInP dWzA== X-Gm-Message-State: AOAM533peNUPbrDWpymPf/fSElaoj/ioBBE38iXMBdITNXuwkI6Yh5kA rhKThpLbuzIuwru1JQ9qpAXHYt+2x++ewIBtb0m3UwaLTrBW7UCqP1qpBCa53uFo1davymsfbul qukXXq8f0fXP9cZE= X-Received: by 2002:a05:600c:510a:: with SMTP id o10mr887633wms.81.1631609670200; Tue, 14 Sep 2021 01:54:30 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzGLf39Vd0e/n2SzQ24dAf/xs3NQ3MVIG12/4U1iTb5PjUT5K8cGAeHTDDsicBhXFcqQzNZFg== X-Received: by 2002:a05:600c:510a:: with SMTP id o10mr887619wms.81.1631609670034; Tue, 14 Sep 2021 01:54:30 -0700 (PDT) Received: from dresden.str.redhat.com ([2a02:908:1e42:9e20:fd73:7ee2:9975:24d9]) by smtp.gmail.com with ESMTPSA id i2sm5736654wrq.78.2021.09.14.01.54.29 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 14 Sep 2021 01:54:29 -0700 (PDT) Subject: Re: [PATCH v3 06/10] qcow2-refcount: check_refcounts_l2(): check l2_bitmap To: Vladimir Sementsov-Ogievskiy , qemu-block@nongnu.org References: <20210524142031.142109-1-vsementsov@virtuozzo.com> <20210524142031.142109-7-vsementsov@virtuozzo.com> From: Hanna Reitz Message-ID: <704ed8a0-387a-d2e7-827f-39957f67b892@redhat.com> Date: Tue, 14 Sep 2021 10:54:28 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <20210524142031.142109-7-vsementsov@virtuozzo.com> Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=hreitz@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Received-SPF: pass client-ip=170.10.133.124; envelope-from=hreitz@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -32 X-Spam_score: -3.3 X-Spam_bar: --- X-Spam_report: (-3.3 / 5.0 requ) DKIMWL_WL_HIGH=-0.398, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-1.969, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action 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, berto@igalia.com, qemu-devel@nongnu.org, mreitz@redhat.com, ktkhai@virtuozzo.com, den@openvz.org, eblake@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 24.05.21 16:20, Vladimir Sementsov-Ogievskiy wrote: > Check subcluster bitmap of the l2 entry for different types of > clusters: > > - for compressed it must be zero > - for allocated check consistency of two parts of the bitmap > - for unallocated all subclusters should be unallocated > (or zero-plain) > > For unallocated clusters we can safely fix the entry by making it > zero-plain. > > Signed-off-by: Vladimir Sementsov-Ogievskiy > Reviewed-by: Eric Blake > Tested-by: Kirill Tkhai > --- > block/qcow2-refcount.c | 30 +++++++++++++++++++++++++++++- > 1 file changed, 29 insertions(+), 1 deletion(-) > > diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c > index f48c5e1b5d..062ec48a15 100644 > --- a/block/qcow2-refcount.c > +++ b/block/qcow2-refcount.c > @@ -1681,6 +1681,7 @@ static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res, > uint64_t coffset; > int csize; > l2_entry = get_l2_entry(s, l2_table, i); > + uint64_t l2_bitmap = get_l2_bitmap(s, l2_table, i); This is a declaration after a statement.  (Easily fixable by moving the l2_entry declaration here, though.  Or by putting the l2_bitmap declaration where l2_entry is declared.) [...] > @@ -1800,6 +1815,19 @@ static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res, > > case QCOW2_CLUSTER_ZERO_PLAIN: > case QCOW2_CLUSTER_UNALLOCATED: > + if (l2_bitmap & QCOW_L2_BITMAP_ALL_ALLOC) { > + res->corruptions++; > + fprintf(stderr, "%s: Unallocated " > + "cluster has non-zero subcluster allocation map\n", > + fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR"); > + if (fix & BDRV_FIX_ERRORS) { > + ret = fix_l2_entry_by_zero(bs, res, l2_offset, l2_table, i, > + active, &metadata_overlap); I believe this is indeed the correct repair method for QCOW2_CLUSTER_ZERO_PLAIN, but I’m not so sure for QCOW2_CLUSTER_UNALLOCATED.  As far as I can tell, qcow2_get_subcluster_type() will return QCOW2_SUBCLUSTER_INVALID for this case, and so trying to read from this clusters will produce I/O errors.  But still, shouldn’t we rather make such a cluster unallocated rather than zero then? And as for QCOW2_CLUSTER_ZERO_PLAIN, I believe qcow2_get_cluster_type() will never return it when subclusters are enabled.  So this repair path will never happen with a cluster type of ZERO_PLAIN, but only for UNALLOCATED. Hanna > + if (metadata_overlap) { > + return ret; > + } > + } > + } > break; > > default: