From patchwork Wed Sep 1 15:15:55 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hanna Czenczek X-Patchwork-Id: 12469635 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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 C7442C432BE for ; Wed, 1 Sep 2021 15:37:45 +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 39F73600EF for ; Wed, 1 Sep 2021 15:37:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 39F73600EF 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]:42578 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mLSJ6-0004E4-EM for qemu-devel@archiver.kernel.org; Wed, 01 Sep 2021 11:37:44 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:49966) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mLRzh-0005cI-Db for qemu-devel@nongnu.org; Wed, 01 Sep 2021 11:17:41 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:27036) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mLRza-0003xX-Tn for qemu-devel@nongnu.org; Wed, 01 Sep 2021 11:17:40 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1630509454; 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=yWI7HfOc4ZaN7Ip2VvLJzPpi6fGTcUvJwalJHHSt93k=; b=UnkYmCgYM7LSdvKbUq8i0Rc+tV4iqSmc1MqM34Fpu23GT/b0gunphDRqOeauMjeBXoQ00P QGXyIMdIN3hz9g0Qr9BxR3EVSf91/pEHQCYXmLboWTyc34jOlNrDGfEDOHKyUNsdmT2ZX3 Kx3tqnW6oboqRFvMEJSLCKai+CCB120= 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-15-loDVQI27OwmBw3WGAAbB0A-1; Wed, 01 Sep 2021 11:17:32 -0400 X-MC-Unique: loDVQI27OwmBw3WGAAbB0A-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 0280CFC81; Wed, 1 Sep 2021 15:17:31 +0000 (UTC) Received: from localhost (unknown [10.39.193.250]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 9AB2760C05; Wed, 1 Sep 2021 15:17:30 +0000 (UTC) From: Hanna Reitz To: qemu-block@nongnu.org Subject: [PULL 32/56] block/copy-before-write: use file child instead of backing Date: Wed, 1 Sep 2021 17:15:55 +0200 Message-Id: <20210901151619.689075-33-hreitz@redhat.com> In-Reply-To: <20210901151619.689075-1-hreitz@redhat.com> References: <20210901151619.689075-1-hreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 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 Received-SPF: pass client-ip=170.10.129.124; envelope-from=hreitz@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -12 X-Spam_score: -1.3 X-Spam_bar: - X-Spam_report: (-1.3 / 5.0 requ) DKIMWL_WL_HIGH=-0.392, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, 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: Kevin Wolf , Peter Maydell , Hanna Reitz , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Vladimir Sementsov-Ogievskiy We are going to publish copy-before-write filter, and there no public backing-child-based filter in Qemu. No reason to create a precedent, so let's refactor copy-before-write filter instead. Signed-off-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Max Reitz Message-Id: <20210824083856.17408-13-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz --- block/copy-before-write.c | 39 ++++++++++++++++++++++----------------- 1 file changed, 22 insertions(+), 17 deletions(-) diff --git a/block/copy-before-write.c b/block/copy-before-write.c index 945d9340f4..7a6c15f141 100644 --- a/block/copy-before-write.c +++ b/block/copy-before-write.c @@ -43,7 +43,7 @@ static coroutine_fn int cbw_co_preadv( BlockDriverState *bs, uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags) { - return bdrv_co_preadv(bs->backing, offset, bytes, qiov, flags); + return bdrv_co_preadv(bs->file, offset, bytes, qiov, flags); } static coroutine_fn int cbw_do_copy_before_write(BlockDriverState *bs, @@ -71,7 +71,7 @@ static int coroutine_fn cbw_co_pdiscard(BlockDriverState *bs, return ret; } - return bdrv_co_pdiscard(bs->backing, offset, bytes); + return bdrv_co_pdiscard(bs->file, offset, bytes); } static int coroutine_fn cbw_co_pwrite_zeroes(BlockDriverState *bs, @@ -82,7 +82,7 @@ static int coroutine_fn cbw_co_pwrite_zeroes(BlockDriverState *bs, return ret; } - return bdrv_co_pwrite_zeroes(bs->backing, offset, bytes, flags); + return bdrv_co_pwrite_zeroes(bs->file, offset, bytes, flags); } static coroutine_fn int cbw_co_pwritev(BlockDriverState *bs, @@ -95,29 +95,22 @@ static coroutine_fn int cbw_co_pwritev(BlockDriverState *bs, return ret; } - return bdrv_co_pwritev(bs->backing, offset, bytes, qiov, flags); + return bdrv_co_pwritev(bs->file, offset, bytes, qiov, flags); } static int coroutine_fn cbw_co_flush(BlockDriverState *bs) { - if (!bs->backing) { + if (!bs->file) { return 0; } - return bdrv_co_flush(bs->backing->bs); + return bdrv_co_flush(bs->file->bs); } static void cbw_refresh_filename(BlockDriverState *bs) { - if (bs->backing == NULL) { - /* - * we can be here after failed bdrv_attach_child in - * bdrv_set_backing_hd - */ - return; - } pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), - bs->backing->bs->filename); + bs->file->bs->filename); } static void cbw_child_perm(BlockDriverState *bs, BdrvChild *c, @@ -186,6 +179,7 @@ BlockDriverState *bdrv_cbw_append(BlockDriverState *source, top = bdrv_new_open_driver(&bdrv_cbw_filter, filter_node_name, BDRV_O_RDWR, errp); if (!top) { + error_prepend(errp, "Cannot open driver: "); return NULL; } @@ -201,21 +195,32 @@ BlockDriverState *bdrv_cbw_append(BlockDriverState *source, state->target = bdrv_attach_child(top, target, "target", &child_of_bds, BDRV_CHILD_DATA, errp); if (!state->target) { + error_prepend(errp, "Cannot attach target child: "); + bdrv_unref(top); + return NULL; + } + + bdrv_ref(source); + top->file = bdrv_attach_child(top, source, "file", &child_of_bds, + BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY, + errp); + if (!top->file) { + error_prepend(errp, "Cannot attach file child: "); bdrv_unref(top); return NULL; } bdrv_drained_begin(source); - ret = bdrv_append(top, source, errp); + ret = bdrv_replace_node(source, top, errp); if (ret < 0) { error_prepend(errp, "Cannot append copy-before-write filter: "); goto fail; } appended = true; - state->bcs = block_copy_state_new(top->backing, state->target, - false, compress, errp); + state->bcs = block_copy_state_new(top->file, state->target, false, compress, + errp); if (!state->bcs) { error_prepend(errp, "Cannot create block-copy-state: "); goto fail;