From patchwork Fri Oct 27 15:53:16 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 13455668 Received: from list by lists.gnu.org with archive (Exim 4.90_1) id 1qwPAB-0003x7-D2 for mharc-qemu-devel@gnu.org; Fri, 27 Oct 2023 11:54:19 -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 1qwP9s-0003X2-45 for qemu-devel@nongnu.org; Fri, 27 Oct 2023 11:54:04 -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 1qwP9p-0002hA-RC for qemu-devel@nongnu.org; Fri, 27 Oct 2023 11:53:59 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1698422035; 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=YJixdduL9wkJySlcO//9WNDhqlP8t6g/aFoESpJs4m4=; b=cZvmsJiUtH+ZjxfB3F1kyS0pKMFIZxRQWejknU1HPQyfVwb4F9/PQYM0Ff8N0t3EeWSXdj qcPFIgNv0ifiP6Tahs0OCPYMEL0pUFU1p/IqF6jiIxX9Wxx+MHI7IM9dfE/qw5iCjzyH/n HRDfWrLx31MNRFUFcIkyO8u0YUgDjUc= 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-82-3Qu7_-3zNMqYno3SBgQwZg-1; Fri, 27 Oct 2023 11:53:51 -0400 X-MC-Unique: 3Qu7_-3zNMqYno3SBgQwZg-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 6B1853821355; Fri, 27 Oct 2023 15:53:51 +0000 (UTC) Received: from merkur.fritz.box (unknown [10.39.194.78]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3E0C85027; Fri, 27 Oct 2023 15:53:50 +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 07/24] block: Mark bdrv_skip_implicit_filters() and callers GRAPH_RDLOCK Date: Fri, 27 Oct 2023 17:53:16 +0200 Message-ID: <20231027155333.420094-8-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 15:54:06 -0000 This adds GRAPH_RDLOCK annotations to declare that callers of bdrv_skip_implicit_filters() need to hold a reader lock for the graph because it calls bdrv_filter_child(), which accesses bs->file/backing. Signed-off-by: Kevin Wolf --- include/block/block_int-global-state.h | 3 ++- block.c | 28 +++++++++++++++++--------- block/monitor/block-hmp-cmds.c | 3 +++ blockdev.c | 14 +++++++------ 4 files changed, 32 insertions(+), 16 deletions(-) diff --git a/include/block/block_int-global-state.h b/include/block/block_int-global-state.h index afce6c4416..ef31c58bb3 100644 --- a/include/block/block_int-global-state.h +++ b/include/block/block_int-global-state.h @@ -277,7 +277,8 @@ BdrvDirtyBitmap *block_dirty_bitmap_remove(const char *node, const char *name, Error **errp); -BlockDriverState *bdrv_skip_implicit_filters(BlockDriverState *bs); +BlockDriverState * GRAPH_RDLOCK +bdrv_skip_implicit_filters(BlockDriverState *bs); /** * bdrv_add_aio_context_notifier: diff --git a/block.c b/block.c index a6060eddbc..7e8b39711b 100644 --- a/block.c +++ b/block.c @@ -4778,6 +4778,8 @@ bdrv_reopen_parse_file_or_backing(BDRVReopenState *reopen_state, return 0; } + bdrv_graph_rdlock_main_loop(); + switch (qobject_type(value)) { case QTYPE_QNULL: assert(is_backing); /* The 'file' option does not allow a null value */ @@ -4787,17 +4789,16 @@ bdrv_reopen_parse_file_or_backing(BDRVReopenState *reopen_state, str = qstring_get_str(qobject_to(QString, value)); new_child_bs = bdrv_lookup_bs(NULL, str, errp); if (new_child_bs == NULL) { - return -EINVAL; + ret = -EINVAL; + goto out_rdlock; } - bdrv_graph_rdlock_main_loop(); has_child = bdrv_recurse_has_child(new_child_bs, bs); - bdrv_graph_rdunlock_main_loop(); - if (has_child) { error_setg(errp, "Making '%s' a %s child of '%s' would create a " "cycle", str, child_name, bs->node_name); - return -EINVAL; + ret = -EINVAL; + goto out_rdlock; } break; default: @@ -4809,18 +4810,21 @@ bdrv_reopen_parse_file_or_backing(BDRVReopenState *reopen_state, } if (old_child_bs == new_child_bs) { - return 0; + ret = 0; + goto out_rdlock; } if (old_child_bs) { if (bdrv_skip_implicit_filters(old_child_bs) == new_child_bs) { - return 0; + ret = 0; + goto out_rdlock; } if (old_child_bs->implicit) { error_setg(errp, "Cannot replace implicit %s child of %s", child_name, bs->node_name); - return -EPERM; + ret = -EPERM; + goto out_rdlock; } } @@ -4831,7 +4835,8 @@ bdrv_reopen_parse_file_or_backing(BDRVReopenState *reopen_state, */ error_setg(errp, "'%s' is a %s filter node that does not support a " "%s child", bs->node_name, bs->drv->format_name, child_name); - return -EINVAL; + ret = -EINVAL; + goto out_rdlock; } if (is_backing) { @@ -4852,6 +4857,7 @@ bdrv_reopen_parse_file_or_backing(BDRVReopenState *reopen_state, aio_context_acquire(ctx); } + bdrv_graph_rdunlock_main_loop(); bdrv_graph_wrlock(new_child_bs); ret = bdrv_set_file_or_backing_noperm(bs, new_child_bs, is_backing, @@ -4870,6 +4876,10 @@ bdrv_reopen_parse_file_or_backing(BDRVReopenState *reopen_state, } return ret; + +out_rdlock: + bdrv_graph_rdunlock_main_loop(); + return ret; } /* diff --git a/block/monitor/block-hmp-cmds.c b/block/monitor/block-hmp-cmds.c index 7645c7e5fb..d55278099d 100644 --- a/block/monitor/block-hmp-cmds.c +++ b/block/monitor/block-hmp-cmds.c @@ -206,6 +206,9 @@ void hmp_commit(Monitor *mon, const QDict *qdict) BlockBackend *blk; int ret; + GLOBAL_STATE_CODE(); + GRAPH_RDLOCK_GUARD_MAINLOOP(); + if (!strcmp(device, "all")) { ret = blk_commit_all(); } else { diff --git a/blockdev.c b/blockdev.c index 240834b6d4..52236f2639 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1737,10 +1737,10 @@ static void drive_backup_action(DriveBackup *backup, assert(format); if (source) { /* Implicit filters should not appear in the filename */ - BlockDriverState *explicit_backing = - bdrv_skip_implicit_filters(source); + BlockDriverState *explicit_backing; bdrv_graph_rdlock_main_loop(); + explicit_backing = bdrv_skip_implicit_filters(source); bdrv_refresh_filename(explicit_backing); bdrv_graph_rdunlock_main_loop(); @@ -3099,16 +3099,18 @@ void qmp_drive_mirror(DriveMirror *arg, Error **errp) bdrv_img_create(arg->target, format, NULL, NULL, NULL, size, flags, false, &local_err); } else { - /* Implicit filters should not appear in the filename */ - BlockDriverState *explicit_backing = - bdrv_skip_implicit_filters(target_backing_bs); + BlockDriverState *explicit_backing; switch (arg->mode) { case NEW_IMAGE_MODE_EXISTING: break; case NEW_IMAGE_MODE_ABSOLUTE_PATHS: - /* create new image with backing file */ + /* + * Create new image with backing file. + * Implicit filters should not appear in the filename. + */ bdrv_graph_rdlock_main_loop(); + explicit_backing = bdrv_skip_implicit_filters(target_backing_bs); bdrv_refresh_filename(explicit_backing); bdrv_graph_rdunlock_main_loop();