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=-6.8 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 653E9C433DF for ; Thu, 25 Jun 2020 15:38:52 +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 2C4A5207D8 for ; Thu, 25 Jun 2020 15:38:52 +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="DB8HRouu" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2C4A5207D8 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]:50222 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1joTxj-0003Ws-Ec for qemu-devel@archiver.kernel.org; Thu, 25 Jun 2020 11:38:51 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:37296) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1joTiO-0005gn-KE for qemu-devel@nongnu.org; Thu, 25 Jun 2020 11:23:01 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:47375 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 1joTiK-0000oM-3e for qemu-devel@nongnu.org; Thu, 25 Jun 2020 11:23:00 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1593098574; 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=2yEX1cwu7AhSnNJ+xZkL8DLXxlRL6pDn3Gj2dmxQeiE=; b=DB8HRouuBcvjLrPUmppzH3hDjtKrtXGZ13RDHzZvRf9RcRlx7YCCZkIDCCECmM/U7wlc9a bRK73rspUxioLbjxePz6WAX41noz6lXbvzH3pYLb61LbI8P2gDyn2bHTQ1O205ZT2P8UJY /bcmH8MCxf5QncXdYdoVxnFDXiYJ/xw= 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-360-b62nW2fXOOuSiKDzXYfpiQ-1; Thu, 25 Jun 2020 11:22:53 -0400 X-MC-Unique: b62nW2fXOOuSiKDzXYfpiQ-1 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 mimecast-mx01.redhat.com (Postfix) with ESMTPS id 53AA61009455; Thu, 25 Jun 2020 15:22:52 +0000 (UTC) Received: from localhost (ovpn-113-182.ams2.redhat.com [10.36.113.182]) by smtp.corp.redhat.com (Postfix) with ESMTPS id EA47C7C214; Thu, 25 Jun 2020 15:22:51 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Subject: [PATCH v7 15/47] block: Use CAFs when working with backing chains Date: Thu, 25 Jun 2020 17:21:43 +0200 Message-Id: <20200625152215.941773-16-mreitz@redhat.com> In-Reply-To: <20200625152215.941773-1-mreitz@redhat.com> References: <20200625152215.941773-1-mreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=205.139.110.61; envelope-from=mreitz@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/06/25 00:45:15 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 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_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=_AUTOLEARN 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 , qemu-devel@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Use child access functions when iterating through backing chains so filters do not break the chain. In addition, bdrv_find_overlay() will now always return the actual overlay; that is, it will never return a filter node but only one with a COW backing file (there may be filter nodes between that node and @bs). Signed-off-by: Max Reitz --- block.c | 41 +++++++++++++++++++++++++++++------------ 1 file changed, 29 insertions(+), 12 deletions(-) diff --git a/block.c b/block.c index a44af9c3c1..712230ef5c 100644 --- a/block.c +++ b/block.c @@ -4724,7 +4724,8 @@ int bdrv_change_backing_file(BlockDriverState *bs, } /* - * Finds the image layer in the chain that has 'bs' as its backing file. + * Finds the image layer in the chain that has 'bs' (or a filter on + * top of it) as its backing file. * * active is the current topmost image. * @@ -4736,11 +4737,18 @@ int bdrv_change_backing_file(BlockDriverState *bs, BlockDriverState *bdrv_find_overlay(BlockDriverState *active, BlockDriverState *bs) { - while (active && bs != backing_bs(active)) { - active = backing_bs(active); + bs = bdrv_skip_filters(bs); + active = bdrv_skip_filters(active); + + while (active) { + BlockDriverState *next = bdrv_backing_chain_next(active); + if (bs == next) { + return active; + } + active = next; } - return active; + return NULL; } /* Given a BDS, searches for the base layer. */ @@ -4892,9 +4900,7 @@ int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base, * other intermediate nodes have been dropped. * If 'top' is an implicit node (e.g. "commit_top") we should skip * it because no one inherits from it. We use explicit_top for that. */ - while (explicit_top && explicit_top->implicit) { - explicit_top = backing_bs(explicit_top); - } + explicit_top = bdrv_skip_implicit_filters(explicit_top); update_inherits_from = bdrv_inherits_from_recursive(base, explicit_top); /* success - we can delete the intermediate states, and link top->base */ @@ -5351,7 +5357,7 @@ BlockDriverState *bdrv_lookup_bs(const char *device, bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base) { while (top && top != base) { - top = backing_bs(top); + top = bdrv_filter_or_cow_bs(top); } return top != NULL; @@ -5607,6 +5613,7 @@ BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, int is_protocol = 0; BlockDriverState *curr_bs = NULL; BlockDriverState *retval = NULL; + BlockDriverState *bs_below; if (!bs || !bs->drv || !backing_file) { return NULL; @@ -5617,7 +5624,17 @@ BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, is_protocol = path_has_protocol(backing_file); - for (curr_bs = bs; curr_bs->backing; curr_bs = curr_bs->backing->bs) { + /* + * Being largely a legacy function, skip any filters here + * (because filters do not have normal filenames, so they cannot + * match anyway; and allowing json:{} filenames is a bit out of + * scope). + */ + for (curr_bs = bdrv_skip_filters(bs); + bdrv_cow_child(curr_bs) != NULL; + curr_bs = bs_below) + { + bs_below = bdrv_backing_chain_next(curr_bs); /* If either of the filename paths is actually a protocol, then * compare unmodified paths; otherwise make paths relative */ @@ -5625,7 +5642,7 @@ BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, char *backing_file_full_ret; if (strcmp(backing_file, curr_bs->backing_file) == 0) { - retval = curr_bs->backing->bs; + retval = bs_below; break; } /* Also check against the full backing filename for the image */ @@ -5635,7 +5652,7 @@ BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, bool equal = strcmp(backing_file, backing_file_full_ret) == 0; g_free(backing_file_full_ret); if (equal) { - retval = curr_bs->backing->bs; + retval = bs_below; break; } } @@ -5661,7 +5678,7 @@ BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, g_free(filename_tmp); if (strcmp(backing_file_full, filename_full) == 0) { - retval = curr_bs->backing->bs; + retval = bs_below; break; } } -- 2.26.2