From patchwork Fri Oct 27 15:53:13 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 13455678 Received: from list by lists.gnu.org with archive (Exim 4.90_1) id 1qwPAN-00050q-3C for mharc-qemu-devel@gnu.org; Fri, 27 Oct 2023 11:54:31 -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 1qwPA4-0003cb-DM for qemu-devel@nongnu.org; Fri, 27 Oct 2023 11:54:14 -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 1qwPA0-0002qh-4z for qemu-devel@nongnu.org; Fri, 27 Oct 2023 11:54:10 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1698422046; 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=8n1p1gBw9ivIpdFQwDES/eILOv+tD05l554oZG6yHTk=; b=Bp/rVhQ5QwiCfOJIUei6ii1ZhNS2Jx3/itQsrFVfUrisQeKAU9nErd1YDqShiJf09aWY4Z 4nFJ1K7Qz/tLBdxSOECInHoYQVws4iWt9ZTRi6VsIuS4FQwxcgbjEH/WsVcrSIhOX7N5pe khmBfbCpNqeEKMQUHcztU3pKvGZUHjA= 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-124-9-Y_BfRiMN-aarNYkc4_HQ-1; Fri, 27 Oct 2023 11:53:47 -0400 X-MC-Unique: 9-Y_BfRiMN-aarNYkc4_HQ-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 323622800B37; Fri, 27 Oct 2023 15:53:47 +0000 (UTC) Received: from merkur.fritz.box (unknown [10.39.194.78]) by smtp.corp.redhat.com (Postfix) with ESMTP id 03CF85027; Fri, 27 Oct 2023 15:53:45 +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 04/24] block: Mark bdrv_root_attach_child() GRAPH_WRLOCK Date: Fri, 27 Oct 2023 17:53:13 +0200 Message-ID: <20231027155333.420094-5-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, SPF_PASS=-0.001 autolearn=unavailable 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 15:54:16 -0000 Instead of taking the writer lock internally, require callers to already hold it when calling bdrv_root_attach_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 --- include/block/block_int-global-state.h | 13 +++++++------ block.c | 5 +---- block/block-backend.c | 2 ++ blockjob.c | 2 ++ 4 files changed, 12 insertions(+), 10 deletions(-) diff --git a/include/block/block_int-global-state.h b/include/block/block_int-global-state.h index 074b677838..afce6c4416 100644 --- a/include/block/block_int-global-state.h +++ b/include/block/block_int-global-state.h @@ -196,12 +196,13 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs, BlockCompletionFunc *cb, void *opaque, JobTxn *txn, Error **errp); -BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs, - const char *child_name, - const BdrvChildClass *child_class, - BdrvChildRole child_role, - uint64_t perm, uint64_t shared_perm, - void *opaque, Error **errp); +BdrvChild * GRAPH_WRLOCK +bdrv_root_attach_child(BlockDriverState *child_bs, const char *child_name, + const BdrvChildClass *child_class, + BdrvChildRole child_role, + uint64_t perm, uint64_t shared_perm, + void *opaque, Error **errp); + void GRAPH_WRLOCK bdrv_root_unref_child(BdrvChild *child); void GRAPH_RDLOCK bdrv_get_cumulative_perm(BlockDriverState *bs, uint64_t *perm, diff --git a/block.c b/block.c index d85738b7dc..5f92eb4950 100644 --- a/block.c +++ b/block.c @@ -3214,8 +3214,6 @@ BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs, GLOBAL_STATE_CODE(); - bdrv_graph_wrlock(child_bs); - child = bdrv_attach_child_common(child_bs, child_name, child_class, child_role, perm, shared_perm, opaque, tran, errp); @@ -3228,9 +3226,8 @@ BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs, out: tran_finalize(tran, ret); - bdrv_graph_wrunlock(); - bdrv_unref(child_bs); + bdrv_schedule_unref(child_bs); return ret < 0 ? NULL : child; } diff --git a/block/block-backend.c b/block/block-backend.c index 53cf3bb8b8..075a0dfa95 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -931,10 +931,12 @@ int blk_insert_bs(BlockBackend *blk, BlockDriverState *bs, Error **errp) ThrottleGroupMember *tgm = &blk->public.throttle_group_member; GLOBAL_STATE_CODE(); bdrv_ref(bs); + bdrv_graph_wrlock(bs); blk->root = bdrv_root_attach_child(bs, "root", &child_root, BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY, blk->perm, blk->shared_perm, blk, errp); + bdrv_graph_wrunlock(); if (blk->root == NULL) { return -EPERM; } diff --git a/blockjob.c b/blockjob.c index 953dc1b6dc..48559fc154 100644 --- a/blockjob.c +++ b/blockjob.c @@ -248,8 +248,10 @@ int block_job_add_bdrv(BlockJob *job, const char *name, BlockDriverState *bs, } aio_context_acquire(ctx); } + bdrv_graph_wrlock(bs); c = bdrv_root_attach_child(bs, name, &child_job, 0, perm, shared_perm, job, errp); + bdrv_graph_wrunlock(); if (need_context_ops) { aio_context_release(ctx); if (job->job.aio_context != qemu_get_aio_context()) {