From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 020E4C433B4 for ; Wed, 21 Apr 2021 14:02:37 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 0995861445 for ; Wed, 21 Apr 2021 14:02:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0995861445 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=yandex-team.ru Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:34660 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lZDR3-0000Zy-8b for qemu-devel@archiver.kernel.org; Wed, 21 Apr 2021 10:02:35 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:43066) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lZDPg-0008UK-N9; Wed, 21 Apr 2021 10:01:08 -0400 Received: from forwardcorp1j.mail.yandex.net ([2a02:6b8:0:1619::183]:46034) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lZDPb-0005nT-UQ; Wed, 21 Apr 2021 10:01:07 -0400 Received: from myt5-23f0be3aa648.qloud-c.yandex.net (myt5-23f0be3aa648.qloud-c.yandex.net [IPv6:2a02:6b8:c12:3e29:0:640:23f0:be3a]) by forwardcorp1j.mail.yandex.net (Yandex) with ESMTP id 7C8362E1567; Wed, 21 Apr 2021 17:00:55 +0300 (MSK) Received: from myt6-76f0a6db1a7e.qloud-c.yandex.net (myt6-76f0a6db1a7e.qloud-c.yandex.net [2a02:6b8:c12:422d:0:640:76f0:a6db]) by myt5-23f0be3aa648.qloud-c.yandex.net (mxbackcorp/Yandex) with ESMTP id kbKjsru6hp-0r00rkGL; Wed, 21 Apr 2021 17:00:55 +0300 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex-team.ru; s=default; t=1619013655; bh=b2MOXubJdz3oWgOppcbDbrIeoYF+Y6v96nIURKYJ3iU=; h=In-Reply-To:Message-ID:Subject:To:From:Cc:References:Date; b=yZqq0Q41jWWA35zNrLoduGGzKs5XghrC8nyMw+8OU66ZHkuKCZHByY068UXHKvqY4 PGd7fhbkva+zSuAowfaZkJl9WtkX4pP8SSeSXKdVmyf5TbGKpDQx5YA/z/XxAJCgK3 LxjE0H3Nwx/e8USsv6YmBXZEW/sagxQxlgqN/smE= Authentication-Results: myt5-23f0be3aa648.qloud-c.yandex.net; dkim=pass header.i=@yandex-team.ru Received: from dynamic-red3.dhcp.yndx.net (dynamic-red3.dhcp.yndx.net [2a02:6b8:0:419:7359:4dc3:71d:4c5a]) by myt6-76f0a6db1a7e.qloud-c.yandex.net (smtpcorp/Yandex) with ESMTPSA id 85bW5lFM9k-0rouX1H3; Wed, 21 Apr 2021 17:00:53 +0300 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (Client certificate not present) Date: Wed, 21 Apr 2021 17:00:49 +0300 From: Roman Kagan To: Vladimir Sementsov-Ogievskiy Subject: Re: [PATCH v3 02/33] block/nbd: fix how state is cleared on nbd_open() failure paths Message-ID: Mail-Followup-To: Roman Kagan , Vladimir Sementsov-Ogievskiy , qemu-block@nongnu.org, qemu-devel@nongnu.org, eblake@redhat.com, mreitz@redhat.com, kwolf@redhat.com, den@openvz.org References: <20210416080911.83197-1-vsementsov@virtuozzo.com> <20210416080911.83197-3-vsementsov@virtuozzo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210416080911.83197-3-vsementsov@virtuozzo.com> Received-SPF: pass client-ip=2a02:6b8:0:1619::183; envelope-from=rvkagan@yandex-team.ru; helo=forwardcorp1j.mail.yandex.net 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, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, 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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, qemu-block@nongnu.org, qemu-devel@nongnu.org, mreitz@redhat.com, den@openvz.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Fri, Apr 16, 2021 at 11:08:40AM +0300, Vladimir Sementsov-Ogievskiy wrote: > We have two "return error" paths in nbd_open() after > nbd_process_options(). Actually we should call nbd_clear_bdrvstate() > on these paths. Interesting that nbd_process_options() calls > nbd_clear_bdrvstate() by itself. > > Let's fix leaks and refactor things to be more obvious: > > - intialize yank at top of nbd_open() > - move yank cleanup to nbd_clear_bdrvstate() > - refactor nbd_open() so that all failure paths except for > yank-register goes through nbd_clear_bdrvstate() > > Signed-off-by: Vladimir Sementsov-Ogievskiy > --- > block/nbd.c | 36 ++++++++++++++++++------------------ > 1 file changed, 18 insertions(+), 18 deletions(-) > > diff --git a/block/nbd.c b/block/nbd.c > index 739ae2941f..a407a3814b 100644 > --- a/block/nbd.c > +++ b/block/nbd.c > @@ -152,8 +152,12 @@ static void nbd_co_establish_connection_cancel(BlockDriverState *bs, > static int nbd_client_handshake(BlockDriverState *bs, Error **errp); > static void nbd_yank(void *opaque); > > -static void nbd_clear_bdrvstate(BDRVNBDState *s) > +static void nbd_clear_bdrvstate(BlockDriverState *bs) > { > + BDRVNBDState *s = (BDRVNBDState *)bs->opaque; > + > + yank_unregister_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name)); > + > object_unref(OBJECT(s->tlscreds)); > qapi_free_SocketAddress(s->saddr); > s->saddr = NULL; > @@ -2279,9 +2283,6 @@ static int nbd_process_options(BlockDriverState *bs, QDict *options, > ret = 0; > > error: > - if (ret < 0) { > - nbd_clear_bdrvstate(s); > - } > qemu_opts_del(opts); > return ret; > } > @@ -2292,11 +2293,6 @@ static int nbd_open(BlockDriverState *bs, QDict *options, int flags, > int ret; > BDRVNBDState *s = (BDRVNBDState *)bs->opaque; > > - ret = nbd_process_options(bs, options, errp); > - if (ret < 0) { > - return ret; > - } > - > s->bs = bs; > qemu_co_mutex_init(&s->send_mutex); > qemu_co_queue_init(&s->free_sema); > @@ -2305,20 +2301,23 @@ static int nbd_open(BlockDriverState *bs, QDict *options, int flags, > return -EEXIST; > } > > + ret = nbd_process_options(bs, options, errp); > + if (ret < 0) { > + goto fail; > + } > + > /* > * establish TCP connection, return error if it fails > * TODO: Configurable retry-until-timeout behaviour. > */ > if (nbd_establish_connection(bs, s->saddr, errp) < 0) { > - yank_unregister_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name)); > - return -ECONNREFUSED; > + ret = -ECONNREFUSED; > + goto fail; > } > > ret = nbd_client_handshake(bs, errp); Not that this was introduced by this patch, but once you're at it: AFAICT nbd_client_handshake() calls yank_unregister_instance() on some error path(s); I assume this needs to go too, otherwise it's called twice (and asserts). Roman. > if (ret < 0) { > - yank_unregister_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name)); > - nbd_clear_bdrvstate(s); > - return ret; > + goto fail; > } > /* successfully connected */ > s->state = NBD_CLIENT_CONNECTED; > @@ -2330,6 +2329,10 @@ static int nbd_open(BlockDriverState *bs, QDict *options, int flags, > aio_co_schedule(bdrv_get_aio_context(bs), s->connection_co); > > return 0; > + > +fail: > + nbd_clear_bdrvstate(bs); > + return ret; > } > > static int nbd_co_flush(BlockDriverState *bs) > @@ -2373,11 +2376,8 @@ static void nbd_refresh_limits(BlockDriverState *bs, Error **errp) > > static void nbd_close(BlockDriverState *bs) > { > - BDRVNBDState *s = bs->opaque; > - > nbd_client_close(bs); > - yank_unregister_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name)); > - nbd_clear_bdrvstate(s); > + nbd_clear_bdrvstate(bs); > } > > /*