From patchwork Thu Oct 12 16:22:13 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 13419442 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 0CFA4CDB47E for ; Thu, 12 Oct 2023 16:29:59 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qqyTL-0003tu-J8; Thu, 12 Oct 2023 12:23:39 -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 1qqyTA-0003pW-Ry for qemu-devel@nongnu.org; Thu, 12 Oct 2023 12:23:29 -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 1qqySy-0000iL-7w for qemu-devel@nongnu.org; Thu, 12 Oct 2023 12:23:28 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1697127795; 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=nUk0LEhDC8wzkomDUXax6IERTNH3jaa23XaMvin57E4=; b=i4ljv5nslER5XH0BuI7LNOttekY0/RPVmdSuWilDeKhZIuTpZUvRFVB6BJ0CKPIxcyfViy GosiCAM24DC1ecBQrwn29fc2QgpjXYqZs6ORpyeglz1Gp/+ek21MSTyH8Xad7fhe+MIfVH 1411oBYygMxtEtOvtFZIfyudnUQakUY= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-444-_wukAmEwOaWhanQ2HoVzQg-1; Thu, 12 Oct 2023 12:22:48 -0400 X-MC-Unique: _wukAmEwOaWhanQ2HoVzQg-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 CBD9628AC1CD; Thu, 12 Oct 2023 16:22:47 +0000 (UTC) Received: from merkur.fritz.box (unknown [10.39.192.233]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3BB1520296DB; Thu, 12 Oct 2023 16:22:47 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Cc: kwolf@redhat.com, qemu-devel@nongnu.org Subject: [PULL 15/26] block: Mark bdrv_primary_child() and callers GRAPH_RDLOCK Date: Thu, 12 Oct 2023 18:22:13 +0200 Message-ID: <20231012162224.240535-16-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 bdrv_primary_child() need to hold a reader lock for the graph because it accesses the children list of a node. Signed-off-by: Kevin Wolf Message-ID: <20230929145157.45443-12-kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- include/block/block_int-io.h | 5 +++-- block.c | 11 ++++++++++- block/snapshot.c | 3 +++ 3 files changed, 16 insertions(+), 3 deletions(-) diff --git a/include/block/block_int-io.h b/include/block/block_int-io.h index eb0da7232e..2b6004ab93 100644 --- a/include/block/block_int-io.h +++ b/include/block/block_int-io.h @@ -133,7 +133,7 @@ bdrv_refresh_total_sectors(BlockDriverState *bs, int64_t hint); BdrvChild *bdrv_cow_child(BlockDriverState *bs); BdrvChild *bdrv_filter_child(BlockDriverState *bs); BdrvChild *bdrv_filter_or_cow_child(BlockDriverState *bs); -BdrvChild *bdrv_primary_child(BlockDriverState *bs); +BdrvChild * GRAPH_RDLOCK bdrv_primary_child(BlockDriverState *bs); BlockDriverState *bdrv_skip_filters(BlockDriverState *bs); BlockDriverState *bdrv_backing_chain_next(BlockDriverState *bs); @@ -155,7 +155,8 @@ static inline BlockDriverState *bdrv_filter_or_cow_bs(BlockDriverState *bs) return child_bs(bdrv_filter_or_cow_child(bs)); } -static inline BlockDriverState *bdrv_primary_bs(BlockDriverState *bs) +static inline BlockDriverState * GRAPH_RDLOCK +bdrv_primary_bs(BlockDriverState *bs) { IO_CODE(); return child_bs(bdrv_primary_child(bs)); diff --git a/block.c b/block.c index 142e1d5e2b..6ce3e2ad7a 100644 --- a/block.c +++ b/block.c @@ -6692,7 +6692,8 @@ void coroutine_fn bdrv_co_debug_event(BlockDriverState *bs, BlkdebugEvent event) bs->drv->bdrv_co_debug_event(bs, event); } -static BlockDriverState *bdrv_find_debug_node(BlockDriverState *bs) +static BlockDriverState * GRAPH_RDLOCK +bdrv_find_debug_node(BlockDriverState *bs) { GLOBAL_STATE_CODE(); while (bs && bs->drv && !bs->drv->bdrv_debug_breakpoint) { @@ -6711,6 +6712,8 @@ int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event, const char *tag) { GLOBAL_STATE_CODE(); + GRAPH_RDLOCK_GUARD_MAINLOOP(); + bs = bdrv_find_debug_node(bs); if (bs) { return bs->drv->bdrv_debug_breakpoint(bs, event, tag); @@ -6722,6 +6725,8 @@ int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event, int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag) { GLOBAL_STATE_CODE(); + GRAPH_RDLOCK_GUARD_MAINLOOP(); + bs = bdrv_find_debug_node(bs); if (bs) { return bs->drv->bdrv_debug_remove_breakpoint(bs, tag); @@ -6733,6 +6738,8 @@ int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag) int bdrv_debug_resume(BlockDriverState *bs, const char *tag) { GLOBAL_STATE_CODE(); + GRAPH_RDLOCK_GUARD_MAINLOOP(); + while (bs && (!bs->drv || !bs->drv->bdrv_debug_resume)) { bs = bdrv_primary_bs(bs); } @@ -6747,6 +6754,8 @@ int bdrv_debug_resume(BlockDriverState *bs, const char *tag) bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag) { GLOBAL_STATE_CODE(); + GRAPH_RDLOCK_GUARD_MAINLOOP(); + while (bs && bs->drv && !bs->drv->bdrv_debug_is_suspended) { bs = bdrv_primary_bs(bs); } diff --git a/block/snapshot.c b/block/snapshot.c index 554065578b..ad2bf6e068 100644 --- a/block/snapshot.c +++ b/block/snapshot.c @@ -311,7 +311,10 @@ int bdrv_snapshot_goto(BlockDriverState *bs, * respective option (with the qdict_put_str() call above). * Assert that .bdrv_open() has attached the right BDS as primary child. */ + bdrv_graph_rdlock_main_loop(); assert(bdrv_primary_bs(bs) == fallback_bs); + bdrv_graph_rdunlock_main_loop(); + bdrv_unref(fallback_bs); return ret; }