From patchwork Tue Dec 5 17:14:41 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Krempa X-Patchwork-Id: 13480510 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id D9659C46CA3 for ; Tue, 5 Dec 2023 17:15:41 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rAZ0d-0006zP-PP; Tue, 05 Dec 2023 12:14:59 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rAZ0a-0006xk-TV for qemu-devel@nongnu.org; Tue, 05 Dec 2023 12:14:56 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rAZ0X-00018Z-M3 for qemu-devel@nongnu.org; Tue, 05 Dec 2023 12:14:56 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1701796493; 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=8SUy7gwXurVOO/8WCWicU8H3pIHc/VgPYRSD9nwubn8=; b=O81jPT9nLvm50cddw+rvQa4HnPBupBkvZHopaAm8Xb4GxLhQotGge7azQKeMhcTGKbkR9v LxVRGtOoZ5OYuv9MaaphVheGgy8MmQ5hZmxi66OJ8raaTTdPdBzST+A+S/oeH6pmvTfdTK HBWyaQRoeaq6f8iR2z6wKlPFcseeM0k= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-147-1tH-LLUEObmD1cBU5oxiIw-1; Tue, 05 Dec 2023 12:14:48 -0500 X-MC-Unique: 1tH-LLUEObmD1cBU5oxiIw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 3E4D488D4E9; Tue, 5 Dec 2023 17:14:48 +0000 (UTC) Received: from speedmetal.lan (unknown [10.45.242.18]) by smtp.corp.redhat.com (Postfix) with ESMTP id 19BE851E3; Tue, 5 Dec 2023 17:14:45 +0000 (UTC) From: Peter Krempa To: qemu-devel@nongnu.org Cc: Kevin Wolf , Hanna Reitz , John Snow , Vladimir Sementsov-Ogievskiy , Eric Blake , Markus Armbruster , qemu-block@nongnu.org Subject: [PATCH v3 1/2] block: commit: Allow users to request only format driver names in backing file format Date: Tue, 5 Dec 2023 18:14:41 +0100 Message-ID: <2cb46e37093ce793ea1604abc8bbb90f4c8e434b.1701796348.git.pkrempa@redhat.com> In-Reply-To: References: MIME-Version: 1.0 Content-type: text/plain X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.5 Received-SPF: pass client-ip=170.10.129.124; envelope-from=pkrempa@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Introduce a new flag 'backing-mask-protocol' for the block-commit QMP command which instructs the internals to use 'raw' instead of the protocol driver in case when a image is used without a dummy 'raw' wrapper. The flag is designed such that it can be always asserted by management tools even when there isn't any update to backing files. The flag will be used by libvirt so that the backing images still reference the proper format even when libvirt will stop using the dummy raw driver (raw driver with no other config). Libvirt needs this so that the images stay compatible with older libvirt versions which didn't expect that a protocol driver name can appear in the backing file format field. Signed-off-by: Peter Krempa Reviewed-by: Vladimir Sementsov-Ogievskiy --- block.c | 37 +++++++++++++++++++++----- block/commit.c | 6 ++++- blockdev.c | 6 +++++ include/block/block-global-state.h | 3 ++- include/block/block_int-common.h | 4 ++- include/block/block_int-global-state.h | 3 +++ qapi/block-core.json | 8 +++++- tests/unit/test-bdrv-drain.c | 3 ++- 8 files changed, 58 insertions(+), 12 deletions(-) diff --git a/block.c b/block.c index bfb0861ec6..771a00a14d 100644 --- a/block.c +++ b/block.c @@ -1309,11 +1309,14 @@ static void bdrv_backing_detach(BdrvChild *c) } static int bdrv_backing_update_filename(BdrvChild *c, BlockDriverState *base, - const char *filename, Error **errp) + const char *filename, + bool backing_mask_protocol, + Error **errp) { BlockDriverState *parent = c->opaque; bool read_only = bdrv_is_read_only(parent); int ret; + const char *format_name; GLOBAL_STATE_CODE(); if (read_only) { @@ -1323,9 +1326,23 @@ static int bdrv_backing_update_filename(BdrvChild *c, BlockDriverState *base, } } - ret = bdrv_change_backing_file(parent, filename, - base->drv ? base->drv->format_name : "", - false); + if (base->drv) { + /* + * If the new base image doesn't have a format driver layer, which we + * detect by the fact that @base is a protocol driver, we record + * 'raw' as the format instead of putting the protocol name as the + * backing format + */ + if (backing_mask_protocol && base->drv->protocol_name) { + format_name = "raw"; + } else { + format_name = base->drv->format_name; + } + } else { + format_name = ""; + } + + ret = bdrv_change_backing_file(parent, filename, format_name, false); if (ret < 0) { error_setg_errno(errp, -ret, "Could not update backing file link"); } @@ -1479,10 +1496,14 @@ static void GRAPH_WRLOCK bdrv_child_cb_detach(BdrvChild *child) } static int bdrv_child_cb_update_filename(BdrvChild *c, BlockDriverState *base, - const char *filename, Error **errp) + const char *filename, + bool backing_mask_protocol, + Error **errp) { if (c->role & BDRV_CHILD_COW) { - return bdrv_backing_update_filename(c, base, filename, errp); + return bdrv_backing_update_filename(c, base, filename, + backing_mask_protocol, + errp); } return 0; } @@ -5961,7 +5982,8 @@ void bdrv_unfreeze_backing_chain(BlockDriverState *bs, BlockDriverState *base) * */ int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base, - const char *backing_file_str) + const char *backing_file_str, + bool backing_mask_protocol) { BlockDriverState *explicit_top = top; bool update_inherits_from; @@ -6027,6 +6049,7 @@ int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base, if (c->klass->update_filename) { ret = c->klass->update_filename(c, base, backing_file_str, + backing_mask_protocol, &local_err); if (ret < 0) { /* diff --git a/block/commit.c b/block/commit.c index 69cc75be0c..4c351644c1 100644 --- a/block/commit.c +++ b/block/commit.c @@ -42,6 +42,7 @@ typedef struct CommitBlockJob { bool base_read_only; bool chain_frozen; char *backing_file_str; + bool backing_mask_protocol; } CommitBlockJob; static int commit_prepare(Job *job) @@ -61,7 +62,8 @@ static int commit_prepare(Job *job) /* FIXME: bdrv_drop_intermediate treats total failures and partial failures * identically. Further work is needed to disambiguate these cases. */ return bdrv_drop_intermediate(s->commit_top_bs, s->base_bs, - s->backing_file_str); + s->backing_file_str, + s->backing_mask_protocol); } static void commit_abort(Job *job) @@ -254,6 +256,7 @@ void commit_start(const char *job_id, BlockDriverState *bs, BlockDriverState *base, BlockDriverState *top, int creation_flags, int64_t speed, BlockdevOnError on_error, const char *backing_file_str, + bool backing_mask_protocol, const char *filter_node_name, Error **errp) { CommitBlockJob *s; @@ -408,6 +411,7 @@ void commit_start(const char *job_id, BlockDriverState *bs, blk_set_disable_request_queuing(s->top, true); s->backing_file_str = g_strdup(backing_file_str); + s->backing_mask_protocol = backing_mask_protocol; s->on_error = on_error; trace_commit_start(bs, base, top, s); diff --git a/blockdev.c b/blockdev.c index 4c1177e8db..9ced07a8c4 100644 --- a/blockdev.c +++ b/blockdev.c @@ -2555,6 +2555,8 @@ void qmp_block_commit(const char *job_id, const char *device, const char *top_node, const char *top, const char *backing_file, + bool has_backing_mask_protocol, + bool backing_mask_protocol, bool has_speed, int64_t speed, bool has_on_error, BlockdevOnError on_error, const char *filter_node_name, @@ -2585,6 +2587,9 @@ void qmp_block_commit(const char *job_id, const char *device, if (has_auto_dismiss && !auto_dismiss) { job_flags |= JOB_MANUAL_DISMISS; } + if (!has_backing_mask_protocol) { + backing_mask_protocol = false; + } /* Important Note: * libvirt relies on the DeviceNotFound error class in order to probe for @@ -2727,6 +2732,7 @@ void qmp_block_commit(const char *job_id, const char *device, } commit_start(job_id, bs, base_bs, top_bs, job_flags, speed, on_error, backing_file, + backing_mask_protocol, filter_node_name, &local_err); } if (local_err != NULL) { diff --git a/include/block/block-global-state.h b/include/block/block-global-state.h index 6b21fbc73f..5f4a6da1fe 100644 --- a/include/block/block-global-state.h +++ b/include/block/block-global-state.h @@ -145,7 +145,8 @@ int GRAPH_RDLOCK bdrv_make_empty(BdrvChild *c, Error **errp); void bdrv_register(BlockDriver *bdrv); int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base, - const char *backing_file_str); + const char *backing_file_str, + bool backing_mask_protocol); BlockDriverState * GRAPH_RDLOCK bdrv_find_overlay(BlockDriverState *active, BlockDriverState *bs); diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h index 4e31d161c5..561f35ddb6 100644 --- a/include/block/block_int-common.h +++ b/include/block/block_int-common.h @@ -985,7 +985,9 @@ struct BdrvChildClass { * can update its reference. */ int (*update_filename)(BdrvChild *child, BlockDriverState *new_base, - const char *filename, Error **errp); + const char *filename, + bool backing_mask_protocol, + Error **errp); bool (*change_aio_ctx)(BdrvChild *child, AioContext *ctx, GHashTable *visited, Transaction *tran, diff --git a/include/block/block_int-global-state.h b/include/block/block_int-global-state.h index ef31c58bb3..2162269df6 100644 --- a/include/block/block_int-global-state.h +++ b/include/block/block_int-global-state.h @@ -82,6 +82,8 @@ void stream_start(const char *job_id, BlockDriverState *bs, * @speed: The maximum speed, in bytes per second, or 0 for unlimited. * @on_error: The action to take upon error. * @backing_file_str: String to use as the backing file in @top's overlay + * @backing_mask_protocol: Replace potential protocol name with 'raw' in + * 'backing file format' header * @filter_node_name: The node name that should be assigned to the filter * driver that the commit job inserts into the graph above @top. NULL means * that a node name should be autogenerated. @@ -92,6 +94,7 @@ void commit_start(const char *job_id, BlockDriverState *bs, BlockDriverState *base, BlockDriverState *top, int creation_flags, int64_t speed, BlockdevOnError on_error, const char *backing_file_str, + bool backing_mask_protocol, const char *filter_node_name, Error **errp); /** * commit_active_start: diff --git a/qapi/block-core.json b/qapi/block-core.json index ca390c5700..726145ec8a 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -1810,6 +1810,11 @@ # Care should be taken when specifying the string, to specify a # valid filename or protocol. (Since 2.1) # +# @backing-mask-protocol: If true, replace any protocol mentioned in the +# 'backing file format' with 'raw', rather than storing the protocol +# name as the backing format. Can be used even when no image header +# will be updated (default false; since 9.0). +# # @speed: the maximum speed, in bytes per second # # @on-error: the action to take on an error. 'ignore' means that the @@ -1856,7 +1861,8 @@ '*base': { 'type': 'str', 'features': [ 'deprecated' ] }, '*top-node': 'str', '*top': { 'type': 'str', 'features': [ 'deprecated' ] }, - '*backing-file': 'str', '*speed': 'int', + '*backing-file': 'str', '*backing-mask-protocol': 'bool', + '*speed': 'int', '*on-error': 'BlockdevOnError', '*filter-node-name': 'str', '*auto-finalize': 'bool', '*auto-dismiss': 'bool' }, diff --git a/tests/unit/test-bdrv-drain.c b/tests/unit/test-bdrv-drain.c index 704d1a3f36..1009dd2d18 100644 --- a/tests/unit/test-bdrv-drain.c +++ b/tests/unit/test-bdrv-drain.c @@ -1638,6 +1638,7 @@ static const BlockJobDriver test_simple_job_driver = { static int drop_intermediate_poll_update_filename(BdrvChild *child, BlockDriverState *new_base, const char *filename, + bool backing_mask_protocol, Error **errp) { /* @@ -1749,7 +1750,7 @@ static void test_drop_intermediate_poll(void) job->should_complete = true; g_assert(!job_has_completed); - ret = bdrv_drop_intermediate(chain[1], chain[0], NULL); + ret = bdrv_drop_intermediate(chain[1], chain[0], NULL, false); aio_poll(qemu_get_aio_context(), false); g_assert(ret == 0); g_assert(job_has_completed);