From patchwork Tue Nov 7 18:45:44 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 13449201 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 C1833C4332F for ; Tue, 7 Nov 2023 18:46:44 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1r0R5j-0003vt-Gb; Tue, 07 Nov 2023 13:46:23 -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 1r0R5d-0003uJ-R9 for qemu-devel@nongnu.org; Tue, 07 Nov 2023 13:46:18 -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 1r0R5b-0001TY-JI for qemu-devel@nongnu.org; Tue, 07 Nov 2023 13:46:17 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1699382772; 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=tSDHhFfE5MUpEEQ9ubxFJ68KIm/3nj5cwYGsrXRHwGk=; b=CqVBnhFvBUnTPoCj3PW3QoUBcobFAnWF3vdezE1WqG+GPZ8M0qYyqy/c1p93VxAsc0ozw/ 8MC35fg3dST3c3JIorfzZYxhVfkqXRdgdGu3xgEgOd1Ar2qvEiMKfz9m+ckK7yLuosB5qU la1vPR8+Ee9sMz7MZS1/uPs+55n29yI= 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-651-10NxzuSEOru66IEy6wQ95A-1; Tue, 07 Nov 2023 13:46:11 -0500 X-MC-Unique: 10NxzuSEOru66IEy6wQ95A-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (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 BE70E1C068D2 for ; Tue, 7 Nov 2023 18:46:10 +0000 (UTC) Received: from merkur.fritz.box (unknown [10.39.194.197]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4A7ADC1596F; Tue, 7 Nov 2023 18:46:10 +0000 (UTC) From: Kevin Wolf To: qemu-devel@nongnu.org Cc: kwolf@redhat.com Subject: [PULL 04/25] block: Mark bdrv_root_attach_child() GRAPH_WRLOCK Date: Tue, 7 Nov 2023 19:45:44 +0100 Message-ID: <20231107184605.236540-5-kwolf@redhat.com> In-Reply-To: <20231107184605.236540-1-kwolf@redhat.com> References: <20231107184605.236540-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.8 Received-SPF: pass client-ip=170.10.129.124; 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_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 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 Message-ID: <20231027155333.420094-5-kwolf@redhat.com> Reviewed-by: Eric Blake 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 5b24de356d..7920f6e500 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()) {