From patchwork Fri Oct 27 15:53:12 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 13455667 Received: from list by lists.gnu.org with archive (Exim 4.90_1) id 1qwPAB-0003vS-3C for mharc-qemu-devel@gnu.org; Fri, 27 Oct 2023 11:54:19 -0400 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 1qwP9o-0003Vi-1R for qemu-devel@nongnu.org; Fri, 27 Oct 2023 11:53:56 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qwP9h-0002a9-RY for qemu-devel@nongnu.org; Fri, 27 Oct 2023 11:53:55 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1698422029; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=l1NnzZCowBmuKNuYhNQ8vcJ+qQQyuvECyRw+quTAl98=; b=OvXlDlzh43I79ILx0iCkbsZ8bfMLw1wKAPAE64g6PW+9ze5NiYfyO+lvECohPzEW3f28tT AXwpvKxZbTBB9YmBkuNe5XPdB/cKWgjXsobRDsrIFBGB00qKp5lSKQft0VE2ZQAbMmZ1Us 1AiIyPUUWsoSaC4m/2Iq4x7puMpSqxc= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-658-IFYSMD3qO3KOmjuVM5ktaA-1; Fri, 27 Oct 2023 11:53:46 -0400 X-MC-Unique: IFYSMD3qO3KOmjuVM5ktaA-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 C1EFC3C23646; Fri, 27 Oct 2023 15:53:45 +0000 (UTC) Received: from merkur.fritz.box (unknown [10.39.194.78]) by smtp.corp.redhat.com (Postfix) with ESMTP id 94F035027; Fri, 27 Oct 2023 15:53:44 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Cc: kwolf@redhat.com, stefanha@redhat.com, eesposit@redhat.com, eblake@redhat.com, pbonzini@redhat.com, vsementsov@yandex-team.ru, qemu-devel@nongnu.org Subject: [PATCH 03/24] block: Mark bdrv_filter_bs() and callers GRAPH_RDLOCK Date: Fri, 27 Oct 2023 17:53:12 +0200 Message-ID: <20231027155333.420094-4-kwolf@redhat.com> In-Reply-To: <20231027155333.420094-1-kwolf@redhat.com> References: <20231027155333.420094-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.5 Received-SPF: pass client-ip=170.10.133.124; envelope-from=kwolf@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_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, T_SPF_TEMPERROR=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: , X-List-Received-Date: Fri, 27 Oct 2023 15:53:57 -0000 This adds GRAPH_RDLOCK annotations to declare that callers of bdrv_filter_bs() need to hold a reader lock for the graph because it calls bdrv_filter_child(), which accesses bs->file/backing. Signed-off-by: Kevin Wolf --- include/block/block-io.h | 2 +- include/block/block_int-io.h | 3 ++- block.c | 9 +++++++-- block/stream.c | 2 ++ migration/block-dirty-bitmap.c | 4 ++++ 5 files changed, 16 insertions(+), 4 deletions(-) diff --git a/include/block/block-io.h b/include/block/block-io.h index ad270b6ad2..58c4cf50a0 100644 --- a/include/block/block-io.h +++ b/include/block/block-io.h @@ -183,7 +183,7 @@ bdrv_co_eject(BlockDriverState *bs, bool eject_flag); const char *bdrv_get_format_name(BlockDriverState *bs); -bool bdrv_supports_compressed_writes(BlockDriverState *bs); +bool GRAPH_RDLOCK bdrv_supports_compressed_writes(BlockDriverState *bs); const char *bdrv_get_node_name(const BlockDriverState *bs); const char * GRAPH_RDLOCK diff --git a/include/block/block_int-io.h b/include/block/block_int-io.h index 34eac72d7a..26bff94e4e 100644 --- a/include/block/block_int-io.h +++ b/include/block/block_int-io.h @@ -143,7 +143,8 @@ static inline BlockDriverState *bdrv_cow_bs(BlockDriverState *bs) return child_bs(bdrv_cow_child(bs)); } -static inline BlockDriverState *bdrv_filter_bs(BlockDriverState *bs) +static inline BlockDriverState * GRAPH_RDLOCK +bdrv_filter_bs(BlockDriverState *bs) { IO_CODE(); return child_bs(bdrv_filter_child(bs)); diff --git a/block.c b/block.c index 1171f47570..d85738b7dc 100644 --- a/block.c +++ b/block.c @@ -820,12 +820,17 @@ int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz) int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo) { BlockDriver *drv = bs->drv; - BlockDriverState *filtered = bdrv_filter_bs(bs); + BlockDriverState *filtered; + GLOBAL_STATE_CODE(); + GRAPH_RDLOCK_GUARD_MAINLOOP(); if (drv && drv->bdrv_probe_geometry) { return drv->bdrv_probe_geometry(bs, geo); - } else if (filtered) { + } + + filtered = bdrv_filter_bs(bs); + if (filtered) { return bdrv_probe_geometry(filtered, geo); } diff --git a/block/stream.c b/block/stream.c index ddaab7dbbd..b22d9c236b 100644 --- a/block/stream.c +++ b/block/stream.c @@ -268,6 +268,8 @@ void stream_start(const char *job_id, BlockDriverState *bs, assert(!bottom->drv->is_filter); base_overlay = above_base = bottom; } else { + GRAPH_RDLOCK_GUARD_MAINLOOP(); + base_overlay = bdrv_find_overlay(bs, base); if (!base_overlay) { error_setg(errp, "'%s' is not in the backing chain of '%s'", diff --git a/migration/block-dirty-bitmap.c b/migration/block-dirty-bitmap.c index 03cb2e72ee..24347ab0f7 100644 --- a/migration/block-dirty-bitmap.c +++ b/migration/block-dirty-bitmap.c @@ -607,6 +607,10 @@ static int init_dirty_bitmap_migration(DBMSaveState *s) BlockBackend *blk; GHashTable *alias_map = NULL; + /* Runs in the migration thread, but holds the iothread lock */ + GLOBAL_STATE_CODE(); + GRAPH_RDLOCK_GUARD_MAINLOOP(); + if (migrate_has_block_bitmap_mapping()) { alias_map = construct_alias_map(migrate_block_bitmap_mapping(), true, &error_abort);