From patchwork Thu Oct 12 16:22:17 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 13419456 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 7F1CACDB47E for ; Thu, 12 Oct 2023 16:31:31 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qqySv-0003fM-Om; Thu, 12 Oct 2023 12:23:13 -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 1qqySt-0003dG-CW for qemu-devel@nongnu.org; Thu, 12 Oct 2023 12:23:11 -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 1qqySb-0000dA-UI for qemu-devel@nongnu.org; Thu, 12 Oct 2023 12:23:10 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1697127773; 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=jEAQXZ7nPkyIQXMGmzvHo0o30n05BeF5a2ngP1GHsOg=; b=S8bqI28URVypWf42TvfOH56+DWSj0vcnXuIMB8PVd3bJd5p26iJARIrWsweTtNwtuE7NGR jD3gn0E6+xiDTMyUhX50+DRkXf7YzB6pc/FU8J5pCTfQoQAptN58hs1Naky8LVqBIUf8AH bBVOsaquGbWbthaRmZwNUtkihWULWQc= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-16-pZvPFpIGNTWmBNmGlRwvaA-1; Thu, 12 Oct 2023 12:22:51 -0400 X-MC-Unique: pZvPFpIGNTWmBNmGlRwvaA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 4DDBC8DBAE1; Thu, 12 Oct 2023 16:22:51 +0000 (UTC) Received: from merkur.fritz.box (unknown [10.39.192.233]) by smtp.corp.redhat.com (Postfix) with ESMTP id B277B2026831; Thu, 12 Oct 2023 16:22:50 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Cc: kwolf@redhat.com, qemu-devel@nongnu.org Subject: [PULL 19/26] qcow2: Mark qcow2_inactivate() and callers GRAPH_RDLOCK Date: Thu, 12 Oct 2023 18:22:17 +0200 Message-ID: <20231012162224.240535-20-kwolf@redhat.com> In-Reply-To: <20231012162224.240535-1-kwolf@redhat.com> References: <20231012162224.240535-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 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, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 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 This adds GRAPH_RDLOCK annotations to declare that callers of qcow2_inactivate() need to hold a reader lock for the graph because it calls bdrv_get_device_or_node_name(), which accesses the parents list of a node. qcow2_do_close() is a bit strange because it is called from different contexts. If close_data_file = true, we know that we were called from non-coroutine main loop context (more specifically, we're coming from qcow2_close()) and can safely drop the reader lock temporarily with bdrv_graph_rdunlock_main_loop() and acquire the writer lock. Signed-off-by: Kevin Wolf Message-ID: <20230929145157.45443-16-kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- block/qcow2.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/block/qcow2.c b/block/qcow2.c index 137c036ea4..aa01d9e7b5 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -2737,14 +2737,12 @@ fail_nometa: return ret; } -static int qcow2_inactivate(BlockDriverState *bs) +static int GRAPH_RDLOCK qcow2_inactivate(BlockDriverState *bs) { BDRVQcow2State *s = bs->opaque; int ret, result = 0; Error *local_err = NULL; - assume_graph_lock(); /* FIXME */ - qcow2_store_persistent_dirty_bitmaps(bs, true, &local_err); if (local_err != NULL) { result = -EINVAL; @@ -2774,7 +2772,8 @@ static int qcow2_inactivate(BlockDriverState *bs) return result; } -static void qcow2_do_close(BlockDriverState *bs, bool close_data_file) +static void coroutine_mixed_fn GRAPH_RDLOCK +qcow2_do_close(BlockDriverState *bs, bool close_data_file) { BDRVQcow2State *s = bs->opaque; qemu_vfree(s->l1_table); @@ -2801,18 +2800,24 @@ static void qcow2_do_close(BlockDriverState *bs, bool close_data_file) g_free(s->image_backing_format); if (close_data_file && has_data_file(bs)) { + GLOBAL_STATE_CODE(); + bdrv_graph_rdunlock_main_loop(); bdrv_graph_wrlock(NULL); bdrv_unref_child(bs, s->data_file); bdrv_graph_wrunlock(); s->data_file = NULL; + bdrv_graph_rdlock_main_loop(); } qcow2_refcount_close(bs); qcow2_free_snapshots(bs); } -static void qcow2_close(BlockDriverState *bs) +static void GRAPH_UNLOCKED qcow2_close(BlockDriverState *bs) { + GLOBAL_STATE_CODE(); + GRAPH_RDLOCK_GUARD_MAINLOOP(); + qcow2_do_close(bs, true); }