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=-9.4 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 B25D0C433E1 for ; Thu, 20 Aug 2020 01:18:40 +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 76E4D2078D for ; Thu, 20 Aug 2020 01:18:40 +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="AY2aecKR" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 76E4D2078D 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]:46348 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1k8ZDz-0005SZ-OA for qemu-devel@archiver.kernel.org; Wed, 19 Aug 2020 21:18:39 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:59810) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k8ZDE-0004wc-S4 for qemu-devel@nongnu.org; Wed, 19 Aug 2020 21:17:52 -0400 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:59539 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 1k8ZDB-0000rX-SD for qemu-devel@nongnu.org; Wed, 19 Aug 2020 21:17:52 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1597886269; 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=XH1IReQjdNkvPwaBkhQNHJksVV/Br90uUBVvpUD4kwI=; b=AY2aecKRKJxe7Kz9etWLZ/d/xwxXa7HdNUE3UZFddNwt3Z0o7178I68yBPsQBmFxG94mjn cuwcvO9x9rURvYBrTYI2/+GVpnw9I3nBGWcFVXwjgku9qbCgsQncZCwXdxj98CPek8yMQL mxfw41Mu1BPxoGepjFAd0ueF4KnQTgo= 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-543-IubC1JZrM4mpkgGo8NJ3bQ-1; Wed, 19 Aug 2020 21:17:45 -0400 X-MC-Unique: IubC1JZrM4mpkgGo8NJ3bQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 7005BD6383; Thu, 20 Aug 2020 01:17:44 +0000 (UTC) Received: from [10.3.112.136] (ovpn-112-136.phx2.redhat.com [10.3.112.136]) by smtp.corp.redhat.com (Postfix) with ESMTPS id AD2E8600DD; Thu, 20 Aug 2020 01:17:43 +0000 (UTC) Subject: Re: [PATCH v4 1/4] migration: Add block-bitmap-mapping parameter To: Max Reitz , qemu-block@nongnu.org References: <20200818133240.195840-1-mreitz@redhat.com> <20200818133240.195840-2-mreitz@redhat.com> From: Eric Blake Organization: Red Hat, Inc. Message-ID: <1c7e187c-fef5-9515-2b4a-f8a32e763ce8@redhat.com> Date: Wed, 19 Aug 2020 20:17:43 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: <20200818133240.195840-2-mreitz@redhat.com> Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eblake@redhat.com X-Mimecast-Spam-Score: 0.002 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=207.211.31.81; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/08/19 20:12:44 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -40 X-Spam_score: -4.1 X-Spam_bar: ---- X-Spam_report: (-4.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-1, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable 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: Kevin Wolf , Vladimir Sementsov-Ogievskiy , Juan Quintela , qemu-devel@nongnu.org, "Dr . David Alan Gilbert" , Peter Krempa , John Snow Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 8/18/20 8:32 AM, Max Reitz wrote: > This migration parameter allows mapping block node names and bitmap > names to aliases for the purpose of block dirty bitmap migration. > > This way, management tools can use different node and bitmap names on > the source and destination and pass the mapping of how bitmaps are to be > transferred to qemu (on the source, the destination, or even both with > arbitrary aliases in the migration stream). > > While touching this code, fix a bug where bitmap names longer than 255 > bytes would fail an assertion in qemu_put_counted_string(). > > Suggested-by: Vladimir Sementsov-Ogievskiy > Signed-off-by: Max Reitz > --- > +## > +# @BitmapMigrationNodeAlias: > +# > +# Maps a block node name and the bitmaps it has to aliases for dirty > +# bitmap migration. > +# > +# @node-name: A block node name. > +# > +# @alias: An alias block node name for migration (for example the > +# node name on the opposite site). > +# > +# @bitmaps: Mappings for the bitmaps on this node. > +# > +# Since: 5.2 > +## > +{ 'struct': 'BitmapMigrationNodeAlias', > + 'data': { > + 'node-name': 'str', > + 'alias': 'str', > + 'bitmaps': [ 'BitmapMigrationBitmapAlias' ] > + } } Possible change: should 'alias' be optional (if absent, it defaults to 'node-name')? But that can be done on top, if we like it. > +static GHashTable *construct_alias_map(const BitmapMigrationNodeAliasList *bbm, > + bool name_to_alias, > + Error **errp) > +{ > + GHashTable *alias_map; > + size_t max_node_name_len = > + sizeof(((BlockDriverState *)NULL)->node_name) - 1; Looks a bit nicer as = sizeof_field(BlockDriverState, node_name) - 1. > + > + alias_map = g_hash_table_new_full(g_str_hash, g_str_equal, > + g_free, free_alias_map_inner_node); > + > + for (; bbm; bbm = bbm->next) { > + const BitmapMigrationNodeAlias *bmna = bbm->value; > + const BitmapMigrationBitmapAliasList *bmbal; > + AliasMapInnerNode *amin; > + GHashTable *bitmaps_map; > + const char *node_map_from, *node_map_to; > + > + if (!id_wellformed(bmna->alias)) { > + error_setg(errp, "The node alias '%s' is not well-formed", > + bmna->alias); > + goto fail; > + } > + > + if (strlen(bmna->alias) > 255) { Magic number. UINT8_MAX seems better (since the limit really is due to our migration format limiting to one byte). ... > + g_hash_table_insert(alias_map, g_strdup(node_map_from), amin); > + > + for (bmbal = bmna->bitmaps; bmbal; bmbal = bmbal->next) { > + const BitmapMigrationBitmapAlias *bmba = bmbal->value; > + const char *bmap_map_from, *bmap_map_to; > + > + if (strlen(bmba->alias) > 255) { and again > + error_setg(errp, > + "The bitmap alias '%s' is longer than 255 bytes", > + bmba->alias); > + goto fail; > + } Thanks for adding in the length checking since last revision! > @@ -326,12 +538,29 @@ static int add_bitmaps_to_list(DBMSaveState *s, BlockDriverState *bs, > return -1; > } > > + if (bitmap_aliases) { > + bitmap_alias = g_hash_table_lookup(bitmap_aliases, bitmap_name); > + if (!bitmap_alias) { > + /* Skip bitmaps with no alias */ > + continue; > + } > + } else { > + if (strlen(bitmap_name) > 255) { > + error_report("Cannot migrate bitmap '%s' on node '%s': " > + "Name is longer than 255 bytes", > + bitmap_name, bs_name); > + return -1; Another one. Reviewed-by: Eric Blake I'm happy to make those touchups, and put this on my bitmaps queue for a pull request as soon as Paolo's meson stuff stabilizes. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org