From patchwork Fri Sep 15 14:43:35 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 1834955 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=F5ySiwkx; dkim-atps=neutral Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=patchwork.ozlabs.org) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4RnHB015pCz1yhZ for ; Sat, 16 Sep 2023 00:48:24 +1000 (AEST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qhA3R-0000O8-M2; Fri, 15 Sep 2023 10:44:21 -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 1qhA3F-0000DX-CS for qemu-devel@nongnu.org; Fri, 15 Sep 2023 10:44:09 -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 1qhA3D-00052K-5x for qemu-devel@nongnu.org; Fri, 15 Sep 2023 10:44:09 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1694789046; 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=XZ1D4R9jhu++H7Mpns8Tpkm6NV/lISKF/b1UzDCZoh4=; b=F5ySiwkxSDQsQ+ffbBS6KNSNM/n9zPTHbFPIyK+VVU7UYQZc157vgGBlk/o/inPmlFrHNj 4n5qBNImFaohepN2Br+/6vf9k2x+GALzbukwgSZloPWgII73OQLYre9VdJ7OA2518zRWYw 7aVxUradUGKTrNmQFDWs4XniSUCiw/w= 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-232-SsxkMUfjOHC4fLzejvNJXw-1; Fri, 15 Sep 2023 10:44:05 -0400 X-MC-Unique: SsxkMUfjOHC4fLzejvNJXw-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 58957811E98; Fri, 15 Sep 2023 14:44:04 +0000 (UTC) Received: from merkur.fritz.box (unknown [10.39.193.146]) by smtp.corp.redhat.com (Postfix) with ESMTP id B9EE82026D4B; Fri, 15 Sep 2023 14:44:03 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Cc: kwolf@redhat.com, qemu-devel@nongnu.org Subject: [PULL 19/28] block: Mark bdrv_root_unref_child() GRAPH_WRLOCK Date: Fri, 15 Sep 2023 16:43:35 +0200 Message-ID: <20230915144344.238596-20-kwolf@redhat.com> In-Reply-To: <20230915144344.238596-1-kwolf@redhat.com> References: <20230915144344.238596-1-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+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Instead of taking the writer lock internally, require callers to already hold it when calling bdrv_root_unref_child(). These callers will typically already hold the graph lock once the locking work is completed, which means that they can't call functions that take it internally. Signed-off-by: Kevin Wolf Reviewed-by: Emanuele Giuseppe Esposito Reviewed-by: Stefan Hajnoczi Message-ID: <20230911094620.45040-20-kwolf@redhat.com> Signed-off-by: Kevin Wolf --- include/block/block_int-global-state.h | 2 +- block.c | 6 +++--- block/block-backend.c | 3 +++ blockjob.c | 2 ++ 4 files changed, 9 insertions(+), 4 deletions(-) diff --git a/include/block/block_int-global-state.h b/include/block/block_int-global-state.h index e2304db58b..074b677838 100644 --- a/include/block/block_int-global-state.h +++ b/include/block/block_int-global-state.h @@ -202,7 +202,7 @@ BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs, BdrvChildRole child_role, uint64_t perm, uint64_t shared_perm, void *opaque, Error **errp); -void bdrv_root_unref_child(BdrvChild *child); +void GRAPH_WRLOCK bdrv_root_unref_child(BdrvChild *child); void GRAPH_RDLOCK bdrv_get_cumulative_perm(BlockDriverState *bs, uint64_t *perm, uint64_t *shared_perm); diff --git a/block.c b/block.c index 8e589bb2e4..9ea8333a28 100644 --- a/block.c +++ b/block.c @@ -3268,7 +3268,6 @@ void bdrv_root_unref_child(BdrvChild *child) BlockDriverState *child_bs = child->bs; GLOBAL_STATE_CODE(); - bdrv_graph_wrlock(NULL); bdrv_replace_child_noperm(child, NULL); bdrv_child_free(child); @@ -3288,8 +3287,7 @@ void bdrv_root_unref_child(BdrvChild *child) NULL); } - bdrv_graph_wrunlock(); - bdrv_unref(child_bs); + bdrv_schedule_unref(child_bs); } typedef struct BdrvSetInheritsFrom { @@ -3366,8 +3364,10 @@ void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child) return; } + bdrv_graph_wrlock(NULL); bdrv_unset_inherits_from(parent, child, NULL); bdrv_root_unref_child(child); + bdrv_graph_wrunlock(); } diff --git a/block/block-backend.c b/block/block-backend.c index 8d0282a5d9..c2636f4351 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -915,7 +915,10 @@ void blk_remove_bs(BlockBackend *blk) blk_drain(blk); root = blk->root; blk->root = NULL; + + bdrv_graph_wrlock(NULL); bdrv_root_unref_child(root); + bdrv_graph_wrunlock(); } /* diff --git a/blockjob.c b/blockjob.c index 25fe8e625d..58c5d64539 100644 --- a/blockjob.c +++ b/blockjob.c @@ -198,6 +198,7 @@ void block_job_remove_all_bdrv(BlockJob *job) * one to make sure that such a concurrent access does not attempt * to process an already freed BdrvChild. */ + bdrv_graph_wrlock(NULL); while (job->nodes) { GSList *l = job->nodes; BdrvChild *c = l->data; @@ -209,6 +210,7 @@ void block_job_remove_all_bdrv(BlockJob *job) g_slist_free_1(l); } + bdrv_graph_wrunlock(); } bool block_job_has_bdrv(BlockJob *job, BlockDriverState *bs)